IPAC2014 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOYBA01	The Very High Intensity Future	target, ion, proton, heavy-ion	17
	J. Wei FRIB, East Lansing, Michigan, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 This paper surveys the key technologies and design challenges that form a basis for the next generation of very high intensity hadron accelerators, including projects operating, under construction, and under design for science and applications at MW beam power level.
	Slides MOYBA01 [7.187 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOYBA01
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MOYBA02	New Design Approaches for High Intensity Superconducting Linacs – The New ESS Linac Design	cryomodule, cavity, klystron, emittance	23
	D.P. McGinnis ESS, Lund, Sweden
	The cost of the next generation of high intensity accelerators has become so large that no single institution can solely afford to fund the construction of the project. To fund these large projects, institutions have embarked on forming ambitious collaboration structures with other laboratories. To induce other laboratories to join the collaboration, compromises must be made in the accelerator technical design to offer interesting and challenging projects to partner institutions. The cost of high intensity hadron accelerators is largely driven by RF system. A new design philosophy different from the traditional approach is emerging for the high intensity frontier machines. Emittance preservation is often less of an issue as long as beam losses are kept low. At ESS modifications were introduced to the linac design. One of the major changes is the reduction of final energy and an increase of gradient and beam current. As a result the design now meets the cost objective but for the price of a higher risk. The accelerator system designer must then try to balance the cost and technical risks while also satisfying the interests and external goals of the partner laboratories.
	Slides MOYBA02 [2.277 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOYBA02
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MOZA02	Advanced RF Design and Tuning Methods of RFQ for High Intensity Proton Linacs	rfq, coupling, dipole, operation	34
	A. France CEA/IRFU, Gif-sur-Yvette, France
	The injector of high intensity linacs includes a Radio Frequency Quadrupole (RFQ) which must sustain high surface fields and thermal effects while accelerating intense low energy beams. For this purpose, the modelisation, realisation and tuning of accurate field laws is mandatory to preserve beam emittances and minimize beam losses. This presentation reviews the progress of advanced methods for the RF design, RF measurements during fabrication and final tuning of RFQ for high intensity linacs. It reports the ongoing developments on the injectors of high intensity demonstrators and of the linacs under construction such as SPIRAL2, LINAC4 or IFMIF-EVEDA.
	Slides MOZA02 [2.026 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOZA02
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MOPRO001	Upgrade Status of Injector LINAC for SuperKEKB	positron, electron, emittance, gun	59
	T. Miura, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	The SuperKEKB collider is under construction to achieve 40-times higher luminosity than that of previous KEKB collider. The injector LINAC should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron for SuperKEKB based on a nano-beam scheme. A photocathode RF-gun for low emittance electron beam has been already installed and the commissioning has started. The construction of positron capture section using a flux-concentrator and the dumping ring for low emittance positron beam is in progress. The simultaneous top-up injections to four storage-rings including photon factories is also required. In the upstream of dumping ring, the compatible optics between positron and electron has been designed. In the downstream of dumping ring, RF phase, focusing, and steering magnets will be switched by pulse to pulse against each beam-mode for optimising beam-transportation. This paper describes recent upgrade status toward the SuperKEKB.
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MOPRO003	Towards Stable Acceleration in Linacs	klystron, acceleration, bunching, electron	65
	A. Dubrovskiy Private Address, Geneve, Switzerland
	Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.
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MOPRO012	Simulating Fast Beam-Ion Instability Studies in FFAG-Based ERHIc Rings	electron, ion, simulation, lattice	83
	G. Wang, V. Litvinenko, Y. Luo BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In an electron accelerator, ions generated from the residual gas by the circulating electrons act back to the trailing electrons. Under unfavorable conditions this feed-back can cause unstable motion of the electron bunches, the process known as the fast beam ion instability. Current eRHIC design has two FFAG rings transporting 21 electron beams at 11 different energies. In this study, we use numerical simulation to investigate the fast ion instability in this complicated system, compare the simulation results with theory and discuss possible measures to mitigate the instability.
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MOPRO034	Studies on Nonlinear Post-linac Protection for CLIC	sextupole, collimation, luminosity, octupole	148
	J. Resta-López Cockcroft Institute, Warrington, Cheshire, United Kingdom S.T. Boogert, J. Snuverink JAI, Egham, Surrey, United Kingdom A. Faus-Golfe, J. Resta-López IFIC, Valencia, Spain
	The post-linac energy collimation system of CLIC is designed to fulfill an essential function of protection of the Beam Delivery System (BDS) against miss-steered beams generated by failure modes in the main linac. Guaranteeing the collimator survivability in case of direct beam impact is very challenging, if we take into account the need to deal with an unprecedented transverse beam energy density per beam of the order of GJ/mm². This translates into a high damage potential of uncontrolled beams. In this paper we present an alternative nonlinear energy collimation system as a potential solution to guarantee the survival of the collimators. The performance and error tolerances of this system are studied by means of beam tracking simulations, and compared with those of the conventional baseline CLIC energy collimation system.
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MOPRO066	Status of FLUTE	laser, gun, electron, diagnostics	231
	M. Schuh, I. Birkel, A. Borysenko, A. Böhm, N. Hiller, E. Huttel, S. Höninger, V. Judin, S. Marsching, A.-S. Müller, A.-S. Müller, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schwarz, M. Weber, P. Wesolowski KIT, Karlsruhe, Germany R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb DESY, Hamburg, Germany H.-H. Braun, R. Ganter, V. Schlott, L. Stingelin PSI, Villigen PSI, Switzerland
	FLUTE, a new linac-based test facility and THz source is currently being built at the Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It consists of an RF photo gun and a traveling wave linac accelerating electrons to beam energies of ~41 MeV in the charge range from a few pC up to 3 nC. The electron bunch will then be compressed in a magnetic chicane in the range of 1 - 300 fs, depending on the charge, in order to generate coherent THz radiation with high peak power. An overview of the simulation and hardware status is given in this contribution.
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MOPRO078	The SPARC_LAB Thomson Source Commissioning	electron, laser, photon, emittance	267
	C. Vaccarezza, D. Alesini, M.P. Anania, M. Bellaveglia, E. Chiadroni, D. Di Giovenale, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, R. Pompili, S. Romeo, F. Villa INFN/LNF, Frascati (Roma), Italy A. Bacci, C. Curatolo, D.T. Palmer, V. Petrillo, A.R. Rossi, L. Serafini, P. Tomassini Istituto Nazionale di Fisica Nucleare, Milano, Italy P. Cardarelli, G. Di Domenico, M. Gambaccini INFN-Ferrara, Ferrara, Italy A. Cianchi INFN-Roma II, Roma, Italy P. Delogu INFN-Pisa, Pisa, Italy F. Filippi, A. Giribono INFN-Roma, Roma, Italy B. Golosio, P. Oliva INFN-Cagliari, Monserrato (Cagliari), Italy A. Mostacci Rome University La Sapienza, Roma, Italy
	The SPARC_LAB Thomson source is presently under commissioning at LNF. An electron beam of energy between 30-150 MeV collides head-on with the laser pulse provided by the Ti:Sapphire laser FLAME, characterized in this phase by a length of 6 ps FWHM and by an energy ranging between 1 and 5 J. The key features of this system are the wide range of tunability of the X-rays yield energy, i.e. 20-500 keV, and the availability of a coupled quadrupole and solenoid focusing system, allowing to reach an electron beam size of 10-20 microns at the interaction point. The experimental results obtained in the February 2014 shifts are presented.
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MOPRO106	Status of the HZB ERL Prototype BERLinPro	gun, cavity, SRF, booster	340
	M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, A. Burrill, V. Dürr, A. Jankowiak, C. Kalus, T. Kamps, G. Klemz, J. Knobloch, J. Kolbe, O. Kugeler, B.C. Kuske, A.N. Matveenko, A. Meseck, A. Neumann, K. Ott, E. Panofski, D. Pflückhahn, J. Rahn, J. Rudolph, M. Schmeißer, S.G. Schubert, O. Schüler, J. Völker, S. Wesch HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association. The Berlin Energy Recovery Linac Prototype BERLinPro is to be constructed at the Helmholtz Zentrum site in Berlin. The aim of the project is to expand the required accelerator physics and technology knowledge mandatory for the generation of a high current (100 mA), high brilliance (norm. emittance below 1 mm mrad) cw electron beam. Since the funding decision in October 2010 the project has entered a phase of detailed planning. Hardware specifications have been defined and various components have been ordered. Furthermore, extensive tests of principal superconducting accelerator components successfully demonstrated the envisaged hardware performance. A summary of the most recent activities together with the details of the project timeline for the coming years are given in this paper.
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MOPRO107	Multi-turn ERL-based Synchrotron Light Facility: Injector Design	emittance, gun, brilliance, booster	343
	A.N. Matveenko, T. Atkinson, A.V. Bondarenko, Y. Petenev HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association VH NG 636 and HRJRG-214 Multi-turn energy recovery linac based light sources are candidates for the future 4th generation synchrotron light sources. Using the superconducting linac technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photon beams of angstrom wavelength at 6 GeV final beam energy. The FSF is intended to be a multi-user facility and offers a variety of operation modes. An overview of the machine layout and magnetic optics design of the installation will be given in this paper with the focus on high brightness injector design.
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MOPRO108	Lattice and Start-to-end Simulation of the Mainz Energy Recovering Superconducting Accelerator MESA	lattice, experiment, simulation, optics	346
	R.G. Heine, K. Aulenbacher, F. Schlander, D. Simon IKP, Mainz, Germany
	Funding: work supported by the German Federal Ministery of Education and Research under the Cluster of Excellence "PRISMA" The institute for nuclear physics (IKPH) at Mainz University is designing a multi turn energy recovery linac for particle physics experiments . We present the current status of the lattice development of MESA together with a PARMELA start to end simulation. R. Heine, K. Aulenbacher, and R. Eichhorn: MESA-Sketch of an Energy Recovery LINAC for Nuclear Physics Experiments at Mainz, Proc. of the IPAC2012, New Orleans, Louisiana, USA, p. 1993-1995.
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MOPRO110	Present Status of the Compact ERL at KEK	recirculation, laser, dipole, injection	353
	N. Nakamura, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, O. Tanaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma JAEA, Ibaraki-ken, Japan J.G. Hwang KNU, Deagu, Republic of Korea M. Kuriki Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan Y. Seimiya HU/AdSM, Higashi-Hiroshima, Japan
	The Compact Energy Recovery Linac (cERL) project is ongoing at KEK in order to demonstrate excellent ERL performance as a future light source. The cERL injector was already constructed with its diagnostic beamline and successfully commissioned from April to June in 2013. In the next step, the cERL recirculation loop with a main superconducting linac and merger and dump sections has been constructed and its commissioning is scheduled to start in December 2013. Significant progress is expected by the IPAC14 conference date. In this presentation, we will describe the present status of the cERL including future developments.
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MOPRO112	Energy Recovering for Linac RF Injectors	cavity, gun, SRF, HOM	356
	V. Volkov, Ya.V. Getmanov, O.A. Shevchenko, N. Vinokurov BINP SB RAS, Novosibirsk, Russia A.N. Matveenko HZB, Berlin, Germany
	The article presents a new design of a CW RF high average current superconducting injector cavity. This design allows recovering energy in the injector, improving beam parameters and energy efficiency, reducing injector size, cost, and avoiding high average power coupler problem.
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MOPRO113	Beam-based HOM Measurements in Cornell's ERL Main Linac Cavity	HOM, cavity, dipole, quadrupole	359
	D.L. Hall, A.C. Bartnik, M.G. Billing, D. Gonnella, G.H. Hoffstaetter, M. Liepe, C.E. Mayes Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	A search for HOMs in Cornell’s ERL main linac cavity installed in a Horizontal Test Cryomodule (HTC) has been carried out using a bunch charge modulation method, as part of the effort towards building an Energy Recovery Linac (ERL). The beam-based HOM measurements offer the significant advantage of being able to detect trapped modes invisible to both the RF pickup probes and HOM damping loads, and allow for measuring the R/Q of the modes. For each HOM detected during the search, measurements were taken to determine its nature (monopole, dipole, etc.), frequency, loaded quality factor and shunt impedance. A selection of the most notable modes found is presented, compared to 3D HOM simulations, and their potential impact on the BBU current of the future Cornell ERL is discussed.
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MOPRO115	A Low Energy Electron-Scrapersystem for the S-DALINAC Injector	electron, acceleration, controls, target	366
	L.E. Jürgensen, T. Bahlo, C. Burandt, F. Hug, T. Kürzeder, N. Pietralla, T. Schösser, C. Ungethüm TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by DFG through SFB 634 The S-DALINAC is the superconducting linear accelerator of the Institut für Kernphysik at Technische Universität Darmstadt. It delivers an electron beam with energies up to 130 MeV. In order to improve the energy spread and the energy stability of the beam for further acceleration a new scrapersystem has been developed and installed between the 10 MeV injector and the main linac. The system was designed to ensure an energy spread of dE < 10^-03. After installation several tests have taken place, the results will be presented in this work.
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MOPME004	RFQ Solver based on the Method of Moments	rfq, simulation, impedance, quadrupole	382
	C. Raucy, C.V.G. Craeye UCL, Louvain-la-Neuve, Belgium D. Vandeplassche SCK•CEN, Mol, Belgium
	Funding: SCK•CEN The aim of this research is to improve the accuracy and the simulation time of solvers devoted to Radio Frequency Quadrupoles (RFQ). The Method of Moments is a full-wave method used to solve scattering problems. Its main advantage over FE or FDTD solvers is that unknowns are limited to the boundaries of the object. The resulting dense system of equations can be solved very rapidly with the help of domain-decomposition approaches (e.g. Macro Basis Functions), especially when the level of detail is very fine compared to the wavelength, which is definitely the case for RFQ’s. Such a method however needs a first regularization method to overcome the low-frequency breakdown in order to compute the Macro Basis Functions. The respective field contributions of different parts of the global structure (e.g. rods vs. stems) can also easily be finely investigated. Numerical results will be presented based on the Myrrha RFQ. The low-frequency breakdown issue due to the very fine mesh will be discussed and a solution based on the so-called Loop-Tree* decomposition will be detailed. * Ozdemir, N.A.; Gonzalez-Ovejero, D.; Craeye, C., IEEE Tr.AP, vol.61, no.4, pp.2088, 2098, April 2013 ** Andriulli, F.P., IEEE Tr.AP, vol.60, no.5, pp.2347, 2356, May 2012
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MOPME017	Study of Higher Order Modes in Multi-Cell Cavities for BESSY-VSR Upgrade	cavity, HOM, SRF, dipole	412
	T. Galek, K. Brackebusch, Sh. Gorgi Zadeh, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Work supported by Federal Ministry for Research and Education BMBF under contract 05K13HR1. BESSY-VSR is a planned scheme to upgrade the existing BESSY II storage ring to support variable electron pulse lengths. In addition to the present 0.5 GHz energy replenishment cavity, two additional SRF bunch compressing cavities operating at 1.5 GHz (3rd harmonic) and 1.75 GHz (sub-harmonic), will be installed. These cavities are essential to produce short 1.5 ps bunches with current of up to 0.8 mA per bunch. In order to achieve such high beam currents, higher order modes must be damped in the superconducting cavities. In this work we present analysis of higher order modes in cavities with different mid-cell shapes.
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MOPME018	Quantification of Geometric Uncertainties in Single Cell Cavities for BESSY VSR using Polynomial Chaos	cavity, simulation, HOM, SRF	415
	J. Heller, T. Flisgen, C. Schmidt, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Federal Ministry for Research and Education Germany under contract 05K13HR1 The electromagnetic properties of SRF cavities are mostly determined by their shape. Due to fabrication tolerances, tuning and limited resolution of measurement systems, the exact shape remains uncertain. In order to make assessments for the real life behaviour it is important to quantify how these geometrical uncertainties propagate through the mathematical system and influence certain electromagnetic properties, like the resonant frequencies of the structure's eigenmodes. This can be done by using non-intrusive straightforward methods like Monte-Carlo (MC) simulations. However, such simulations require a large number of deterministic problem solutions to obtain a sufficient accuracy. In order to avoid this scaling behaviour, the so-called polynomial chaos (PC) expansion is used. This technique allows for the relatively fast computation of uncertainty propagation for few uncertain parameters in the case of computationally expensive deterministic models. In this paper we use the PC expansion to quantify the propagation of uncertain geometry on the example of single cell cavities used for BESSY VSR as well as to compare the obtained results with the MC simulation.
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MOPME032	PIC Simulations in Low Energy Part of PIP-II Proton Linac	rfq, simulation, emittance, proton	448
	G.V. Romanov Fermilab, Batavia, Illinois, USA
	The front end of PIP-II linac is composed of a 30 keV ion source, low energy beam transport line (LEBT), 2.1 MeV radio frequency quadrupole (RFQ), and medium energy beam transport line (MEBT). This configuration is currently being assembled at Fermilab to support a complete systems test. The front end represents the primary technical risk with PIP-II, and so this step will validate the concept and demonstrate that the hardware can meet the specified requirements. SC accelerating cavities right after MEBT require high quality and well defined beam after RFQ to avoid excessive particle losses. In this paper we will present recent progress of beam dynamic study, using CST PIC simulation code, to investigate partial neutralization effect in LEBT, halo and tail formation in RFQ, total emittance growth and beam losses along low energy part of the linac.
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MOPME035	Current Status of the GPU-Accelerated ELEGANT	GPU, operation, simulation, acceleration	454
	I.V. Pogorelov, K.M. Amyx, J.R. King Tech-X, Boulder, Colorado, USA M. Borland, R. Soliday ANL, Argonne, Ilinois, USA
	Funding: Work supported by the DOE Office of Science, Office of Basic Energy Sciences grant No. DE-SC0004585, and in part by Tech-X Corporation. Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale tracking simulations. This presentation is an update on the current status of our work on accelerating Argonne National Lab’s particle accelerator simulation code ELEGANT using CUDA-enabled GPU. We summarize the performance of beamline elements ported to GPU, and discuss optimization techniques for some important collective effects kernels, in particular our methods of avoiding costly thread contention. We also present preliminary results of a scaling study of the GPU-accelerated version of the code.
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MOPME046	Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex	software, operation, monitoring, hardware	476
	M. Audrain, D. Anderson, M. Dragu, K. Fuchsberger, J.C. Garnier, A.A. Gorzawski, M. Koza, K.H. Krol, A. Moscatelli, B. Puccio, K. Stamos, M. Zerlauth CERN, Geneva, Switzerland
	The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integration of the Beam Interlock System software into the operational environment.
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MOPME059	Design of a Multi-harmonic Buncher for LINCE	ion, rfq, bunching, operation	508
	J. Labrador, C. Bonțoiu, J.A. Dueñas, I. Martel University of Huelva, Huelva, Spain M.A. Carrera, A. Garbayo AVS, Elgoibar, Spain A.C.C. Villari FRIB, East Lansing, Michigan, USA
	Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA. Continuous beams delivered by the LINCE ECR ion source will be bunched by a multi-harmonic buncher consisting of two copper-made electrodes. Its numerical design is reported here along with electric and magnetic field maps. Multi-frequency operation is proven by tracking a continuous beam and optimizing the its longitudinal phase space bunching for various ion species under the influence of space charge effects. A thermo-mechanical study carried out in order to estimate the needed water flow through the electrodes is presented as well.
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MOPRI002	Design, Manufacture and Operation of the Beam Spoiler for Positron Target Protection	target, positron, electron, alignment	573
	L. Zang, K. Kakihara, T. Kamitani, K. Mikawa, F. Miyahara, T. Suwada KEK, Ibaraki, Japan
	In order to produce positrons, intensive pulsed electron beam is used to strike on a tungsten target. The energy deposition is distributed non-uniformly over the target, leading to a mechanical stress. As a result of large thermal gradient, the target could be potentially damaged. To avoid the target destruction, the peak energy deposition density (PEDD) in the target should be well below the critical limit (35J/g) based on the SLAC operational experience. With an expected primary electron spot size on the target of the SuperKEKB positron source, the PEDD will exceeds the limit. We will introduce a beam spoiler to enlarge the spot size by multiple scattering in thin beam screen and aluminum plate. It reduces the PEDD down to half of the limit. This paper describes the design of the spoiler and the beam screen system used in the positron beam commissioning of the SuperKEKB positron source started in 2014.
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MOPRI036	Pulse Radiolysis Using Terahertz Probe Pulses	electron, laser, radiation, gun	676
	K. Kan, M. Gohdo, T. Kondoh, K. Norizawa, I. Nozawa, A. Ogata, T. Toigawa, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	Pulse radiolysis, which utilizes a pump electron beam and a probe pulse, is a powerful tool that can be used for the time-resolved observation of ultrafast radiation-induced phenomena. Recently, double-decker pulse radiolysis* using visible probe pulses were demonstrated based on a photocathode RF gun driven by two UV pulses, which enabled synchronized pump electron beam and visible probe pulses. In this study, pulse radiolysis using terahertz (THz) probe pulses which were realized by the “double-decker” electron beams and dynamics of transient quasi-free electrons in semiconductors are presented. * K. Kan et al., Rev. Sci. Instrum. 83, 073302 (2012).
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MOPRI037	Development of Iridium Cerium Photocathode for the Generation of High-Charge Electron Beam	laser, electron, cathode, gun	679
	D. Satoh TIT, Tokyo, Japan N. Hayashizaki RLNR, Tokyo, Japan T. Natsui, M. Yoshida KEK, Ibaraki, Japan
	We developed an iridium cerium cathode material made by new production method for multi-purpose electron source. For multi-purpose electron source, we focused on the Ir5Ce compound which has a high melting point (> 2100 K) and a low work function (2.57 eV). This material has some excellent properties as both a thermionic cathode and a photocathode. For example, Ir5Ce thermionic cathode can generate one-order higher electrical current than a LaB6 cathode at the same temperature. Another advantage is that an Ir5Ce thermionic cathode has a lifetime two orders longer than that of a LaB6 thermionic cathode under the same conditions. Moreover, we discovered that this material has a reasonably high quantum efficiency (2.70 × 10−3 @213nm at 1000°C) and long-lifetime (> LaB6) as a photocathode. Our research shows that Ir5Ce compound is optimum material for a thermionic cathode and photocathode. We focused on this good emission properties under the high temperature and we tried to develop a backside electron beam heating system and demonstrate a laser pre-pulse heating for a high current thermionic gun system or high charge photocathode gun.
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MOPRI054	Status of the APEX Project at LBNL	gun, cathode, cavity, FEL	727
	F. Sannibale, K.M. Baptiste, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, D. Filippetto, G.L. Harris, G. Huang, H. Huang, R. Huang, T.D. Kramasz, S. Kwiatkowski, R.E. Lellinger, V. Moroz, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, J.W. Staples, M. Vinco, S.P. Virostek, R.P. Wells, M.S. Zolotorev LBNL, Berkeley, California, USA R. Huang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 The Advanced Photo-injector EXperiment (APEX) at the Lawrence Berkeley National Laboratory (LBNL), consists in the development of an injector designed to demonstrate the capability of the VHF gun, a normal conducting 186 MHz RF gun operating in CW mode, to deliver the brightness required by X-ray FEL applications at MHz repetition rate. APEX is organized in 3 main phases where different aspects of the required performance are gradually demonstrated. The status and future plans for the project are presented.
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MOPRI082	Acceleration of High-Intensity Heavy-Ion Beams at RIKEN RI Beam Factory	ion, ion-source, cyclotron, ECRIS	800
	O. Kamigaito, T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, T. Nakagawa, M. Nakamura, J. Ohnishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe, K. Yamada, H. Yamasawa RIKEN Nishina Center, Wako, Japan T. Nagatomo RIKEN, Saitama, Japan
	Recent efforts concerning the RIBF accelerators in RIKEN have been directed towards achieving higher beam intensities of very heavy ions such as uranium and xenon. As presented in the last IPAC conference in 2013, the intensities of these ion beams have significantly improved due to the construction of a new injector, RILAC2, which is equipped with a 28-GHz superconducting ECR ion source, the development of a helium gas stripper, and upgrading of the bending power of the fRC. In this light, this paper presents the subsequent upgrade programs carried out in the last couple of years, such as developments of a new air stripper for xenon beams and a micro-oven for metallic ions. The current performance level of the RIBF accelerator complex, as well as a future plan to further increase the beam intensities, are also presented.
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MOPRI090	Beam Distribution Transformation with SFMs at 3MeV C-ADS Beamline	target, beam-transport, quadrupole, rfq	824
	H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The C-ADS project is building a test facility at the Institute of High Energy Physics. The design goal of the test facility is 10MeV beam energy with a continuous beam current of 10mA. To sustain the 100kW CW beam power at the beam dump, a beam distribution transform system is designed. The Step Field Magnets (SFMs) are used to transform the beam distribution from Gaussian to uniform. In this test stand, two sets of SFMs will be employed to manipulate the beam distribution. At the first commissioning stage, the bump dump line will be connected to the Medium Energy Beam Transport-1 (MEBT1) to test the beam manipulation scheme. The design and error analysis of this 3MeV beam dump line will be discussed in this paper.
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MOPRI103	Longitudinal Bunch Shortening for the Laser Stripping Project	laser, cavity, focusing, acceleration	861
	T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, V.V. Danilov, Y. Liu, M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation. Realization of high efficiency laser stripping at the SNS accelerator needs good longitudinal overlap between H⁻ bunch and laser pulse. The default H⁻ bunch length at the interaction point is 5 times bigger than needed in order to achieve 90% stripping efficiency. Theoretical and experimental studies of longitudinal H⁻ bunch shortening are presented in this paper.
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MOPRI108	Transverse H⁻ Beam Halo Scraper System in the J-PARC L3BT	radiation, injection, proton, operation	876
	K. Okabe, M. Kinsho, K. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-mura, Japan
	In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), transverse beam halo scraping for the injection beam is required to increase the output beam power. The transverse collimation system at the Linac-RCS beam transport line (L3BT) was utilized in a nominal beam operation because the area of the scraper section was contaminated when scrapers were working. In the summer-autumn period of 2013, we installed a new beam-halo scraper which had optimized scraper heads for mitigation of the radiation around the scraper system. In this poster, we report a preliminary result for a halo scraper at the L3BT.
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TUXA01	Commissioning the 400 MeV Linac at J-PARC and High Intensity Operation of the J-PARC RCS	injection, dipole, emittance, operation	899
	H. Hotchi JAEA/J-PARC, Tokai-mura, Japan
	J-PARC is currently upgrading their linac from 181MeV to 400 MEV with a new ACS section (annular coupled structure). This includes a triple frequency jump, and there should be some interesting results to report. As the result of the injector linac upgrade at J-PARC, the Rapid Cycle Synchrotron (RCS) will achieve a record-high intensity as a proton accelerator. This talk describes the recent performance of the RCS together with its beam-dynamical issues.
	Slides TUXA01 [3.611 MB]
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TUOBA02	Design Study of an ERL Test Facility at CERN	electron, cryomodule, cavity, optics	921
	E. Jensen, C. Bracco, O.S. Brüning, R. Calaga, N. Catalán Lasheras, B. Goddard, R. Torres-Sanchez, A. Valloni CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom
	The modern concept of an Energy Recovery Linac allows providing large electron currents at large beam energy with low power consumption. This concept is used in FEL’s, electron-ion colliders and electron coolers. CERN has started a Design Study of an ERL Test Facility with the purpose of 1) studying the ERL principle, its specific beam dynamics and operational issues, as relevant for LHeC, 2) providing a test bed for superconducting cavity modules, cryogenics and integration, 3) studying beam induced quenches in superconducting magnets and protection methods, 4) providing test beams for detector R&D and other applications. It will be complementary to existing or planned facilities and is fostering international collaboration. The operating frequency of 802 MHz was chosen for performance and for optimum synergy with SPS and LHC; the design of the cryomodule has started. The ERL Test Facility can be constructed in stages from initially 150 MeV to ultimately 1 GeV in 3 passes, with beam currents of up to 80 mA. Parameters to serve the above-mentioned purposes are well defined and possible lattice designs have well advanced.
	Slides TUOBA02 [14.419 MB]
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TUZA02	THz Facility at ELBE: A Versatile Test Facility for Electron Bunch Diagnostics on Quasi-CW Electron Beams	electron, diagnostics, SRF, operation	933
	M. Gensch, B.W. Green, J. Hauser, S. Kovalev, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig HZDR, Dresden, Germany A. Al-Shemmary, V. B. Asgekar, T. Golz, H. Schlarb, N. Stojanovic, S. Vilcins DESY, Hamburg, Germany A.S. Fisher SLAC, Menlo Park, California, USA G. Geloni XFEL. EU, Hamburg, Germany A.-S. Müller, M. Schwarz KIT, Karlsruhe, Germany N.E. Neumann, D. Plettemeier TU Dresden, Dresden, Germany
	At the Helmholtz-Zentrum Dresden-Rossendorf near Dresden a quasi-cw low-energy electron linear accelerator based on superconducting radiofrequency technology is operated successfully for more than 10 years. The ELBE accelerator is driving several secondary radiation sources including 2 infrared free electron lasers. A new addition will be a THz facility that aims to make use of super-radiant THz radiation. In its final form the THz facility shall consist of one coherent diffraction radiator and one undulator source which provide high-field THz pulses at unprecedented repetition rates. While the medium term goal is to establish a unique user facility for nonlinear THz science, the THz sources are already used as a test facility for novel diagnostic techniques on quasi-cw electron beams. The progress of the developments is reported and an outlook into future challenges and opportunities is given.
	Slides TUZA02 [3.041 MB]
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TUOCA01	The Linac Coherent Light Source-II Project	electron, undulator, cryomodule, laser	935
	J.N. Galayda SLAC, Menlo Park, California, USA
	Funding: Work supported by US DOE Contract DE-AC02-766SF00515 The “Linac Coherent Light Source–II” Project, initiated in September 2010, has gone through a radical transformation beginning in August 2013. In its new form, LCLS-II will construct a 4 GeV CW superconducting linac in the first kilometre of the existing linac tunnel. A new undulator, optimized as a soft x-ray (200-1,300 eV) source, will receive electrons from the new SC linac. The existing undulator system will be replaced with a new variable gap device, which will receive electrons from either the new SC linac (providing 1-5 keV photons) or the copper linac presently used by LCLS (providing 1-25 keV x-rays). First light from the new facility is expected in September 2019. galayda@slac.stanford.edu
	Slides TUOCA01 [9.380 MB]
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TUOCA02	Status of the Free Electron Laser User Facility FLASH	FEL, flattop, gun, laser	938
	M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch DESY, Hamburg, Germany
	FLASH, the Free Electron Laser User Facility at DESY (Hamburg, Germany), delivers high brilliance XUV and soft X-ray FEL radiation to photon experiments. After a shutdown to connect the second undulator beamline FLASH2 to the FLASH linac, re-commissioning of FLASH started in autumn 2013. The year 2014 is dedicated to FLASH1 user experiments. The commissioning of the FLASH2 beamline takes place in 2014 in parallel to FLASH1 operation.
	Slides TUOCA02 [9.156 MB]
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TUPRO036	Start-to-end Optic of the FSF Multi-turn ERL Project	emittance, injection, undulator, simulation	1099
	T. Atkinson, A.V. Bondarenko, A.N. Matveenko, Y. Petenev HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association VH NG 636 and HRJRG-214 Advanced magnetic optic designs are required to meet the heavy demands of future light sources: diffraction limited emittance, femto-second pulses and low energy spread. This paper highlights the magnetic optic that is presently being investigated in the ERL-simulation group at HZB. The injector optic is based on subtle emittance compensation techniques of space charge dominated beams. The high energy arcs are designed to suppress emittance growth due to CSR through horizontal phase advance manipulation, ISR effects by keeping the radiation integrals small and reduce the degradation due to chromatic aberrations. Optimised Start-to-End beam dynamic simulations are presented.
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TUPRO038	Beam Positioning Concept and Tolerance Considerations for BERLinPro	laser, emittance, gun, timing	1105
	B.C. Kuske, J. Rudolph HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association BERLinPro is an ERL project at Helmholtz-Zentrum Berlin, with the goal to illuminate the challenges and promises of a high brightness 100 mA superconducting RF gun in combination with a 50 MeV return loop and energy recovery [1, 2]. The precision of the beam position in a single turn machine might be relaxed compared to the demands in storage rings. Still, a trajectory correction concept has to be developed and the influence of trajectory offsets on the goal parameters, its dependence on fluctuating injection parameters or effects related to the low energy of 6.5-50 MeV have to be investigated. This paper covers the initial trajectory correction studies and first tolerance scenarios of BERLinPro using the projected hardware concept.
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TUPRO043	Status and Computer Simulations for the Front End of the Proton Injector for Fair	proton, ion, simulation, extraction	1120
	C. Ullmann, R. Berezov, J. Fils, R. Hollinger, V. Ivanova, O.K. Kester, W. Vinzenz GSI, Darmstadt, Germany N. Chauvin, O. Delferrière CEA/IRFU, Gif-sur-Yvette, France
	FAIR - the international facility for antiproton and ion research – located at GSI in Darmstadt, Germany is one of the largest research projects worldwide. It will provide an antiproton production rate of 7·10¹⁰ cooled pbars per hour, which is equivalent to a primary proton beam current of 2·1016 protons per hour. A high intensity proton linac (p-linac) will be built, with an operating rf-frequency of 325 MHz to accelerate a 70 mA proton beam up to 70 MeV, using conducting crossed-bar H-cavities. The repetition rate is 4 Hz with an ion beam pulse length of 36 μs[1]. Developed within a joint French-German collaboration - GSI/CEA-SACLAY/IAP – the compact proton linac will be injected by a microwave ion source and a low energy beam transport (LEBT). The 2.45 GHz ion source allows high brightness ion beams at an energy of 95 keV and will deliver a proton beam current of 100 mA at the entrance of the RFQ (Radio Frequency Quadrupole) within an emittance of 0.3π mm mrad (rms). To check on these parameters computer simulations with TraceWin, IGUN and IBSIMU of the ion extraction and LEBT (Low Energy Beam Transport) are performed.
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TUPRO044	Bunch Compression of the Low-energy ELBE Electron Beam for Super-radiant THz Sources	radiation, electron, emittance, undulator	1123
	U. Lehnert, P. Michel, R. Schurig HZDR, Dresden, Germany A.A. Aksoy Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey P.E. Evtushenko JLab, Newport News, Virginia, USA J.M. Krämer Danfysik A/S, Taastrup, Denmark
	At the ELBE radiation source two super-radiant THz sources, a broad-band trasnsition/diffraction radiation source and a planar undulator narrow-band sourc are under commissioning. At present the facility is driven from the ELBE linac with a CW electron beam of 100kHz repetition rate and up to 100pC of bunch charge. With the upgraded SRF electron gun bunch charges up to 1nC will become available. For the beam energies in the 20-30 MeV range buch compression into the sub-200 fs range becomes a major challenge. We present beam dynamics calculation of the attempted bunch compression scheme as well as first measurements obtained during the commissioning.
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TUPRO050	Measurements of the Optical Functions at FLASH	optics, quadrupole, controls, coupling	1141
	J. Zemella, T. Hellert, M. Scholz, M. Vogt DESY, Hamburg, Germany
	In 2013 the superconducting soft x-ray Free Electron Laser FLASH at DESY (Hamburg, Germany) the extraction section needed to connect the 2nd beam line FLASH2 was installed. In order to allow simultaneous operation of the two beam lines (FLASH1/2), the optical functions in the extraction area needed to be modified. During the recommissioning of FLASH we have optimized, measured and corrected the optical functions in the machine. We report on the the results and the methods.
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TUPRO053	Design and Optimization of Racetrack Microtron for Laser Compton Scattered Gamma-ray Sources	electron, simulation, dipole, injection	1150
	R. Hajima JAEA/ERL, Ibaraki, Japan M. Ferdows JAEA, Ibaraki-ken, Japan
	Funding: This work is supported by Funds for Integrated Promotion of Social System Reform and Research and Development. Racetrack microtron (RTM) is a compact accelerator to obtain electron beams with an energy above 100 MeV. Conventional RTM's have been designed to accelerate a train of electron bunch from a thermionic electron gun, where the bunch charge is typically 10 pC. In the industrial application of laser Compton scattered gamma-ray sources, RTM with 200-300 MeV electron energy will be a suitable device to produce 2-3 MeV gamma-ray beams. Single electron bunch from a photocathode RF gun is accelerated and a high-charge small-emittance beam is preferable in such RTM. In this paper, we adopt a simulation code, GPT, for design and optimization of RTM in view of high-charge and small-emittance beam generation.
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TUPRO055	Design Status of the RISP Test Facility LEBT	rfq, ECR, simulation, quadrupole	1156
	R.M. Bodenstein, D. Jeon IBS, Daejeon, Republic of Korea J. Bahng Kyungpook National University, Daegu, Republic of Korea
	Funding: Supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea Project No. 2011-0032011 Raon, the rare isotope accelerator of the the Rare Isotope Science Project (RISP) in Daejeon, South Korea, is being designed to accelerate multiple-charge-state beams simultaneously. Using an Electron Cyclotron Resonance (ECR) Ion Source to produce the ions, Raon will transport the beam through two 90-degree bending magnets and a Low Energy Beam Transport (LEBT) system to a Radio Frequency Quadrupole (RFQ). In order to test the components of the injector and LEBT system, a test facility is under development. A new LEBT, based upon the LEBT of the main driver linac, is being designed to fit within the test facility’s restrictive space requirements. This work will briefly review the main driver linac LEBT design, and then discuss the current status of the test facility LEBT design.
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TUPRO056	Merit Functions for the Linac Optics Design for Colliders and Light Sources	optics, emittance, focusing, quadrupole	1159
	S. Di Mitri, M. Cornacchia Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy H.-S. Kang PAL, Pohang, Kyungbuk, Republic of Korea
	Optics matching and transverse emittance preservation are key goals for a successful operation of modern high brightness electron linacs. The capability of controlling them in a real machine critically relies on a properly designed magnetic lattice. Conscious of this fact, we introduce an ensemble of optical functions* that permit to solve the often neglected conflict between strong focusing, typically implemented to counteract coherent synchrotron radiation and transverse wakefield instability, and distortion of the transverse phase space induced by chromatic aberrations and focusing errors. A numerical evaluation of the merit functions is applied to existing and planned linac-based free electron lasers. *S. Di Mitri and M. Cornacchia, Nucl. Instr. Meth. Phys. Research A 735, 60–65 (2014).
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TUPRO061	Benchmarking Beam Envelope Models for the European Spallation Source	DTL, simulation, dipole, space-charge	1174
	I. List Cosylab, Ljubljana, Slovenia E. Laface ESS, Lund, Sweden
	TraceWin is used at the European Spallation Source (ESS) as the design tool, while fast and accurate on-line models will be needed during the operations. Three models are compared: the ESS Linac Simulator (ELS), TraceWin and the OpenXAL. In all of the benchmarked models, dynamics of each beam-line element is, to the first order, represented by a transfer matrix. Differences in the matrices occur, since different reference frames are used and as well different assumptions about the energy of the particles are made. General transformations of the reference frames will be presented. Using those, the comparison of transfer maps among TraceWin and OpenXAL are given. When the differences between TraceWin and OpenXAL were unclear, the benchmark versus other code, like MAD-X and Dynac was done. The best implementations were combined into a new on-line model implementation Java ELS (or JELS) and at last the comparison of the latter with TraceWin is given.
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TUPRO064	Scaling Laws of Wake Field Effects for Gradient Changes in the CLIC Main Linac	wakefield, emittance, simulation, damping	1183
	J. Pfingstner, A. Latina, D. Schulte CERN, Geneva, Switzerland
	The main linac of CLIC is designed to maximize the transportable bunch charge, since this parameter determines the energy efficiency of the CLIC accelerating structures. The bunch charge is limited by short-range wake field effects, which increase the projected beam emittance. For the main linac cost optimisation, it is important to understand how the charge limit scales with the change of the gradient of the accelerating structures. In this paper, we determine such a scaling law via simulations studies. It is shown that from different possible scenarios, the charge limit for a lower gradient CLIC structure scales advantageous and a relatively high charge can be used.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO064
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TUPRO065	Tests of Beam-based Alignment at FACET	wakefield, emittance, simulation, alignment	1186
	A. Latina, J. Pfingstner, D. Schulte CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	Tests of Beam-Based Alignment have been performed at FACET, with successful results. A flight simulator based on PLACET has been put in place to test the correction algorithms before applying the correction to the real machine. The flight simulator not only helped studying the parameters space in a safe environment, but it also helped developing a graphical interface that the experimenter can use to set each parameter of the correction also during the on-line.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO065
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TUPRO091	Simple Characterization Method of Small High Gradient Permanent Magnet Quadrupoles	quadrupole, proton, focusing, permanent-magnet	1250
	C. Ronsivalle, L. Picardi, M. Vadrucci ENEA C.R. Frascati, Frascati (Roma), Italy F. Ambrosini URLS, Rome, Italy
	The application of quadrupoles with high or ultra-high gradient and small apertures requires a precise control over harmonic components of the field. A simple, fast, low cost measurement method on small size PMQs (Permanent Magnet Quadrupoles) is described. It is based on the same principle of the familiar "rotating coil technique", but in this case, profiting of the small dimensions of the PMQ, it consists in rotating the PMQ itself instead of the coil. In such way a gain on accuracy and measure time is obtained. It has been applied to characterize a set of commercial PMQs with a gradient around 200 T/m and an internal radius of 3.5 mm to be mounted in a SCDTL (Side Coupled Drift Tube Linac) structure for the acceleration of a proton beam from 7 to 12 MeV. This structure has been developed in the framework of the Italian TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for Radiotherapy) Project
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO091
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TUPRO095	Using One-dimensional Hall Probe to Measure the Solenoid Magnet for CSNS/RCS	solenoid, collimation, synchrotron, insertion	1262
	Z. Zhang, S. Li, F. Long, X.J. Sun IHEP, Beijing, People's Republic of China
	Abstract CSNS(China Spallation Neutron Source) construction is expected to start in 2010 and will last 6.5 years. A long beam transport line is followed with the DTL linac to send the beam a rapid cycling synchrotron (RCS) accelerator. The beam will be focused by the solenoid magnet. This magnet will be located in LEBT system. It has been used with one-dimensional Hall probe to measurement by Institute of High Energy Physics, China. After the measurement, the measurement results meet the design requirements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO095
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TUPRO100	Rare-Earth End Magnets of a Miniature Race-Track Microtron and their Tuning	microtron, quadrupole, simulation, permanent-magnet	1277
	I.Yu. Vladimirov, N.I. Pakhomov, V.I. Shvedunov MSU, Moscow, Russia Yu.A. Kubyshin UPC, Barcelona, Spain J.P. Rigla I3M, Valencia, Spain V.V. Zakharov Tehnomag ltd., Kaluga, Russia
	We report on the tuning of end magnets of a compact 12 MeV racetrack microtron (RTM) which is under construction at the Technical University of Catalonia. They are magnetic systems composed of four dipoles with the Rare-Earth Permanent Magnet (REPM) material used as a source of the magnetic field. The poles of the magnets are equipped with tuning plungers which allow to adjust the magnetic field level. In the article we describe the tuning procedure and different techniques that were used in order to fulfill strict requirements of the field characteristics of the end magnets. It is shown that the obtained magnetic systems provide correct beam trajectories in the 12 MeV RTM.
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TUPRO104	Design of the Beam Transfer Line Magnets for HIE-ISOLDE	dipole, quadrupole, lattice, operation	1289
	J. Bauche, A.V. Aloev CERN, Geneva, Switzerland
	This paper describes the design of the beam transfer line magnets of the HIE-ISOLDE facility. The technical solutions selected to face the challenges associated with the machine requirements are presented, and the final design parameters and field quality are reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO104
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TUPME002	An Optimization of Positron Injector of ILC	positron, target, electron, booster	1334
	M. Kuriki, Y. Seimiya HU/AdSM, Higashi-Hiroshima, Japan S. Kashiwagi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan T. Okugi, M. Satoh, J. Urakawa KEK, Ibaraki, Japan
	Funding: This work is supported by Photon and Quantum Basic Research Coordinated Development Program of MEXT. ILC (International Linear Collider) is a future project of high energy physics. In the current baseline design, positron generation by gamma rays from undulator radiation is assumed. However, this approach is totally new and it is very difficult to demonstrate the system prior to the construction because it requires more than 100 GeV beam as the driver. A conventional positron generation (e-driven) has been proposed as a technical backup option. In this method, the technology is well established, but the issue is to obtain an enough amount of positron with a manageable energy deposition on target. We present a result of a systematic study of capture efficiency defined by DR (Damping Ring) acceptance where the beam emittance is reduced by radiation damping. We performed a start-to-end simulation of the positron source of ILC and found that an enough amount of the positron per bunch is obtained with a manageable energy deposition on the production target.
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TUPME012	The US Muon Accelerator Program	collider, factory, proton, target	1367
	M.A. Palmer Fermilab, Batavia, Illinois, USA
	Funding: Work supported by US DOE under contract DE-AC02-07CH11359. A directed R&D program is presently underway in the U.S. to evaluate the designs and technologies required to provide muon-based high energy physics (HEP) accelerator capabilities. Such capabilities have the potential to provide unique physics reach for the HEP community. An overview of the status of the designs for the neutrino factory and muon collider applications is provided. Recent progress in the technology R&D program is summarized.
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TUPME013	Thermo-mechanical Tests for the CLIC Two-beam Module Study	operation, alignment, vacuum, experiment	1370
	A. Xydou, G. Riddone, A.L. Vamvakas CERN, Geneva, Switzerland E. Daskalaki NTUA, Athens, Greece
	The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite element analysis model and propagated back to engineering design. Finally, simulation of the most possible CLIC machine cycles is accomplished and preliminary results are analysed.
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TUPME040	Drive Beam Break-up Control and Practical Gradient Limitation in Collinear Dielectric Wakefield Accelerators	wakefield, acceleration, simulation, quadrupole	1443
	C. Li, W. Gai, J.G. Power, A. Zholents ANL, Argonne, Illinois, USA C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA C. Li, C.-X. Tang TUB, Beijing, People's Republic of China
	Dielectric wakefield accelerator (DWA) concept has gained significant attention for the need of the future large scale facilities. For a practical machine, one needs to overcome a major challenge for the DWA that is the efficient energy extraction and stable propagation at the same time for the drive beam. Typically, a slightly off axis beam become unstable in the dielectric channel due to transverse wakefield excitation, that could be controlled if a strong external alternating magnetic focusing channel applied at the same time. However, there is limitation on the practical magnetic field in the focusing channel (typically < 1 Tesla), thus imposing operating point for the DWA. In this article, we explore the operating point of the DWA for various structure frequencies and drive beam charge, particularly on the gradient and total acceleration distance, and provide guidance on the DWA design.
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TUPME041	The Advanced Superconducting Test Accelerator at Fermilab: Science Program	SRF, electron, emittance, laser	1447
	P. Piot, E.R. Harms, S. Henderson, J.R. Leibfritz, S. Nagaitsev, V.D. Shiltsev, A. Valishev Fermilab, Batavia, Illinois, USA
	Funding: This work is supported by DOE contract DE-AC02-07CH11359 to the Fermi Research Alliance LLC The Advanced Superconducting Test Accelerator (ASTA) currently in commissioning phase at Fermilab is foreseen to support a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop novel approaches to particle-beam generation, acceleration and manipulation. ASTA incorporates a superconducting radiofrequency (SCRF) linac coupled to a flexible high-brightness photoinjector. The facility also includes a small-circumference storage ring capable of storing electrons or protons. This report summarizes the facility capabilities, and provide an overview of the accelerator-science researches to be enabled.
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TUPME047	SINBAD - A Proposal for a Dedicated Accelerator Research Facility at DESY	plasma, experiment, electron, laser	1466
	R.W. Aßmann, C. Behrens, R. Brinkmann, U. Dorda, K. Flöttmann, B. Foster, J. Grebenyuk, I. Hartl, M. Hüning, Y.C. Nie, J. Osterhoff, A. Rühl, H. Schlarb, B. Schmidt DESY, Hamburg, Germany M. Groß, B. Marchetti, F. Stephan DESY Zeuthen, Zeuthen, Germany F.J. Grüner, B. Hidding, A.R. Maier Uni HH, Hamburg, Germany F.X. Kärtner, B. Zeitler CFEL, Hamburg, Germany A.-S. Müller, M. Schuh KIT, Karlsruhe, Germany
	A new, dedicated accelerator research facility SINBAD (Short INnovative Bunches and Accelerators at DESY) is proposed. This facility is aimed at promoting two major goals: (1) Short electron bunches for ultra-fast science. (2) Construction of a plasma accelerator module with useable beam quality. Research and development on these topics is presently ongoing at various places at DESY, as add-on experiments at operational facilities. The two research goals are intimately connected: short bunches and precise femtosecond timing are requirements for developing a plasma accelerator module. The scientific case of a dedicated facility for accelerator research at DESY is discussed. Further options are mentioned, like the use of a 1 GeV beam from Linac2 for FEL studies and the setup of an attosecond radiation source with advanced technology. The presently planned conversion of the DORIS storage ring and its central halls into the SINBAD facility is described. The available space will allow setting up several independent experiments with a cost-effective use of the same infrastructure. National and international contributions and proposals can be envisaged.
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TUPME084	On the Frequency Choice for the eRHIC SRF Linac	SRF, cavity, HOM, electron	1547
	S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, V. Ptitsyn, W. Xu BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, V. Ptitsyn Stony Brook University, Stony Brook, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE. eRHIC is a future electron-hadron collider proposed at BNL. It will collide high-intensity hadron beams from one of the existing rings of RHIC with a 50-mA electron beam from a multi-pass 10-GeV superconducting RF (SRF) Energy Recovery Linac (ERL). A novel approach to the multi-pass ERL utilizing a non-scaling FFAG was recently proposed. It has many advantages over the previous designs including significant cost savings. The current design has 11 passes in two FFAG rings. To mitigate various beam dynamics effects, it was proposed to lower RF frequency of the SRF linac from 704 MHz used in the previous design. In this paper we consider different effects driving the frequency choice of the SRF ERL and present our arguments for choosing lower RF frequency.
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TUPRI001	ESSnuSB: A New Facility Concept for the Production of Very Intense Neutrino Beams in Europe	proton, target, detector, simulation	1550
	E. Bouquerel, E. Baussan, M. Dracos, F.R. Osswald, P. Poussot, N. Vassilopoulos IPHC, Strasbourg Cedex 2, France
	A new project for the production of a very intense neutrino beam has arisen to enable the discovery of leptonic CP violation and neutrino mass hierarchy. This facility will use the proton linac of the European Spallation Source (ESS) in Lund to deliver the neutrino super beam. The ESS linac is expected to be fully operational at 5 MW power by 2022, producing 2 GeV and 2.86 ms long proton pulses at a rate of 14 Hz. An upgrade of the power to 10 MW and a frequency of 28 Hz, in which half is for the neutron beam, is necessary for the production of the neutrino beam. The primary proton beam-line completing the linac will consist of switchyards and accumulator rings. The secondary beam-line producing neutrinos will consist of a four-horn/target station, decay tunnel and beam dump. A megaton scale water Cherenkov detector will be located at a baseline of about 500 km in one of the existing mines in Sweden and it will measure the neutrino oscillations. The elements of the primary and secondary beam-lines and all the possible scenarios impacting the design of the ESSnuSB facility as well as the safety issues due to the high irradiation produced are presented and discussed in this paper.
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TUPRI002	The EUROnu Study for Future High Power Neutrino Oscillation Facilities	target, detector, factory, proton	1553
	T.R. Edgecock STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The EUROnu project was a 4 year FP7 design study to investigate and compare three possible options for future, high power neutrino oscillation facilities in Europe. These three facilities are a Neutrino Factory, a neutrino superbeam from CERN to the Frejus Laboratory and a so-called Beta Beam. The study was completed at the end of 2012 and has produced conceptual designs for the facilities and preliminary cost estimates. The designs were used to determine the physics performance. These have been used to compare the facilities. This paper will describe the designs, physics performance and costs and summarise the recommendations of the study.
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TUPRI044	Investigation of Microbunching-instability in BERLinPro	electron, simulation, space-charge, emittance	1662
	S.D. Rädel, A. Jankowiak, A. Meseck HZB, Berlin, Germany
	Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association BERLinPro is using the new energy recovery linac technology. As, maintaining the low emittance and energy spread is of major importance in an ERL, the deep understanding and control of effects which can degrade the emittance and energy spread such as space charge effects are of interest. The microbunching caused by the longitudinal space charge forces can lead to an increase in emittance and energy spread in the arcs of the loop. In this contribution, the impacts of the microbunching instability on the beam quality and its implication for BERLinPro are discussed.
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TUPRI080	Emittance Optimisation in the Drive Beam Recombination Complex at CTF3	emittance, feedback, controls, simulation	1754
	D. Gamba, F. Tecker CERN, Geneva, Switzerland D. Gamba JAI, Oxford, United Kingdom
	According to the Conceptual Design Report, the power to accelerate the main colliding beams of CLIC is taken from parallel high intensity (100 A), low energy (2.37 GeV) beams. These beams are generated by long trains, accelerated by conventional klystrons and then time-compressed in the so called Drive-Beam Recombination Complex (DBRC). A scaled version of the DBRC has been built at the CLIC Test Facility (CTF3) at CERN in order to prove its principle and study any arising feasibility issues. One of the main constraints is the emittance control during the recombination process. This work presents an overview of the studies ongoing at CTF3, keeping in view possible improvements of the nominal CLIC design. In particular, a generic feedback algorithm to solve (quasi-)linear systems has been implemented and used in order to optimise the process by tuning the energy of the beam and steer the orbits in the different lines, as well matching the design dispersion. Current results and possible room for further optimisation will be shown.
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TUPRI090	Linac Alignment for SuperKEKB Injector	alignment, laser, emittance, positron	1781
	T. Higo, K. Kakihara, T. Kamitani, M. Satoh, R. Sugahara, T. Suwada, M. Tanaka KEK, Ibaraki, Japan
	The misalignment of the linac beamline components amounted to be a millimeter level during the operation of KEKB, though the requirement of 0.1mm in mind. The limited effort toward improving such big misalignments has long been pursued but could not finish especially after the earthquake in March 2011. This linac is now under upgrade to the SuperKEKB, where the required alignment is 0.1mm in σ for the short distance in 100m span, while 0.3mm through the whole linac for the emittance preservation. The straight line as a reference for the alignment was defined by laser beam over 500m. The actual hardwares are set with respect to this reference line by using a laser tracker. The alignment present status is reported in this paper. On the other hand, we noticed, through the alignment measurements over months, that the tunnel floor moved in the range of 0.1mm or maybe more. The evaluation of this movement is on-going to discuss about how to achieve the required emittance and how to keep the situation. Various measurements to evaluate the movement are presented also in the paper.
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TUPRI091	Refinement of ARC Alignment between Two Straight Sections for Injector Linac of SuperKEKB	alignment, laser, emittance, quadrupole	1784
	M. Tanaka, T. Higo, K. Kakihara, T. Kamitani KEK, Ibaraki, Japan K. Kimura, K. Suzuki, N. Toyotomi, S. Ushimoto Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
	The beam line of the KEKB injector linac is under realignment as the restoration after the big Earthquake in 2011, but with the refinement for the SuperKEKB in mind. The linac consists of two straight sections connected by a 180 degree ARC. Precise alignment of the ARC magnets is one of the key issues for the emittance preservation of the electron beam. The ARC beam line was defined by measuring these two straight lines. Then, the misalignment of the ARC magnets were reduced from 3 mm maximum down to 0.1mm in the errors perpendicular to the beam direction. This paper describes how we defined the ARC beam line and performed the alignment. The connection method of the laser tracker data needed for the definition of the ARC was also studied and described.
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TUPRI092	Improvement of the Position Monitor using White Light Interferometer for Measuring Precise Movement of Compact ERL Superconducting Cavities in Cryomodule	target, cryomodule, cavity, operation	1787
	H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori KEK, Ibaraki, Japan T. Aoto, K. Hayashi, K. Kanzaki Tokyo Seimitsu Co. Ltd, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2K cooling with the resolution of 10um. However, some drift come from outer temperature and humidity were observed. In this paper, we describe the upgraded version of this monitor to suppress these drift for cERL beam operation.
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TUPRI095	Design and Study on a 5 Degree-of-freedom Adjustment Platform for CLIC Drive Beam Quadrupoles	quadrupole, alignment, linear-collider, collider	1796
	M. Sosin, M. Anastasopoulos, M. Duquenne, J. Kemppinen, H. Mainaud Durand, V. Rude, J. Sandomierski CERN, Geneva, Switzerland
	Since several years CERN is studying the feasibility of building a high energy e⁺ e⁻ linear collider: the CLIC (Compact LInear Collider). The pre-alignment precision and accuracy requirement for the transverse positions of the linac components is typically 14 micrometers over a sliding window of 200m. One of the challenges is precise adjustment of Drive Beam quadrupole’s magnetic axis. It has to be done with micrometric resolution along 5 DOF in a common support’s coordinate system. This paper describes the design and the study of a solution based on flexural components in a type of “Stewart Platform” configuration. The engineering approach, the lessons learned (“know how”), the issues of adjustment solution and the mechanical components behaviors are presented.
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TUPRI098	The New PLC based Radiation Safety Interlock System at S-DALINAC	electron, radiation, operation, status	1802
	M. Arnold, J. Birkhan, M. Brunken, J. Conrad, M. Hess, F. Hug, N. Pietralla, S.T. Sievers, P. von Neumann-Cosel TU Darmstadt, Darmstadt, Germany
	Funding: Supported by a HGS-HIRe travel grant The Superconducting Darmstadt Linear Electron Accelerator S-DALINAC has been running since 1991. It consists of an injector linac, a main linac with two recirculations and is mainly used for in-house nuclear physics experiments as well as accelerator physics and technology. Radiation safety regulations demand an interlock system during operation of the accelerator. Amongst other major projects increasing the versatility and operation stability of the S-DALINAC, the existing, hardware based, interlock system is going to be replaced in the next shutdown period. The new interlock system is based on a PLC (Programmable Logic Controller) and will provide two subsystems, a personnel interlock system as well as a machine safety interlock system. Whereas the first subsystem is to protect staff and visitors from being harmed by ionizing radiation, the latter subsystem prohibits the S-DALINAC beam transport and vacuum elements from being damaged due to malfunctioning of any components during accelerator operation. This contribution will give an overview on this new system and will show the latest status.
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TUPRI109	Construction and Commissioning of Event Timing System at SuperKEKB	timing, injection, positron, software	1829
	H. Kaji, K. Furukawa, M. Iwasaki, E. Kikutani, T. Kobayashi, F. Miyahara, T.T. Nakamura, M. Satoh, M. Suetake, M. Tobiyama KEK, Ibaraki, Japan T. Kudo, S. Kusano Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan T. Okazaki EJIT, Hitachi, Ibaraki, Japan
	The Event Timing System of Injector Linac at KEK is upgraded to satisfy the new requirements for the SuperKEKB project. After finishing the design and feasibility studies, we have constructed the new system at Main Trigger Station of Linac. The new functions are developed in this system to perform the injection control of positrons with the newly constructed damping ring. Besides, we integrate the capability to adjust the trigger timing just 20 ms before injection so that the injection RF-bucket of the ring can be decided at the last minute. Now, both the new system and the current working system are operational at Main Trigger Station. This is important for the smooth taking over of Event Timing System. Even during the construction period, Linac must be operated to provide beams into the two light source rings. In this situation, we can carry out enough tests with the actual condition. These tests do not disturb the regular operation and brush up the Event Timing System to enable the quick startup of the SuperKEKB operation. We report about the detailed configuration of the new system and its commissioning performed in the 2014 spring run period. H. Kaji et al., "Upgrade of Event Timing System at SuperKEKB", proceedings of ICALEPCS13, San Francisco, USA, October 6-11, 2013.
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WEYA01	Challenges of Radioactive Beam Facilities – Comparing Solutions at SPIRAL2 and FAIR	ion, target, ISOL, heavy-ion	1852
	R. Ferdinand GANIL, Caen, France
	The SPIRAL2 facility at GANIL will use a high-power p, d and heavy-ion driver to produce RIB though both ISOL and in-flight techniques. The SPIRAL2-injector beam is expected before the end of 2014. The construction of the FAIR facility has started at GSI and the outline of the accelerator complex is well defined. A clear strategy and construction schedule is defined in the framework of the international FAIR collaboration. This talk will give an overview of the accelerators at both facilities and compare the characteristics and benefits of these two approaches to meet their user needs.
	Slides WEYA01 [9.134 MB]
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WEOBA02	Superconducting Linac for Rare Isotope Science Project	cavity, cryomodule, ion, proton	1861
	H.J. Kim, H.J. Cha, M.O. Hyun, H. Jang, H.C. Jung, Y. Kim, M. Lee, G.-T. Park IBS, Daejeon, Republic of Korea
	Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.5 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the status of RISP linac design and the development of superconducting cavity and cryomodule.
	Slides WEOBA02 [9.226 MB]
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WEZA02	A Staged Muon Accelerator Facility for Neutrino and Collider Physics	collider, factory, proton, target	1872
	J.-P. Delahaye SLAC, Menlo Park, California, USA C.M. Ankenbrandt, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, S.D. Holmes, R.J. Lipton, D.V. Neuffer, M.A. Palmer Fermilab, Batavia, Illinois, USA S.A. Bogacz JLab, Newport News, Virginia, USA P. Huber Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA D.M. Kaplan, P. Snopok Illinois Institute of Technology, Chicago, Illinois, USA H.G. Kirk, R.B. Palmer BNL, Upton, Long Island, New York, USA R.D. Ryne LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Dept. of Energy under contracts DE-AC02-07CH11359 and DE-AC02-76SF00515 Muon-based facilities offer unique potential to provide capabilities at both the Intensity Frontier with Neutrino Factories and the Energy Frontier with Muon Colliders. They rely on a novel technology with challenging parameters, for which the feasibility is currently being evaluated by the Muon Accelerator Program (MAP). A realistic scenario for a complementary series of staged facilities with increasing complexity and significant physics potential at each stage has been developed. It takes advantage of and leverages the capabilities already planned for Fermilab, especially the strategy for long-term improvement of the accelerator complex being initiated with the Proton Improvement Plan (PIP-II) and the Long Baseline Neutrino Facility (LBNF). Each stage is designed to provide an R&D platform to validate the technologies required for subsequent stages. The rationale and sequence of the staging process and the critical issues to be addressed at each stage, are presented.
	Slides WEZA02 [27.263 MB]
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WEOAB03	Linear Electron Acceleration in THz Waveguides	electron, acceleration, laser, accelerating-gradient	1896
	E.A. Nanni, W.S. Graves, K.-H. Hong, W.R. Huang, F.X. Kärtner, KR. Ravi, L.J. Wong MIT, Cambridge, Massachusetts, USA A. Fallahi, F.X. Kärtner CFEL, Hamburg, Germany R.J.D. Miller DESY, Hamburg, Germany G. Moriena University of Toronto, Toronto, Ontario, Canada
	Funding: Supported by DARPA N66001-11-1-4192, CFEL DESY, DOE DEFG02-10ER46745, DOE DE-FG02-08ER41532, ERC Synergy Grant 609920 and NSF DMR-1042342. We report the first experimental demonstration of linear electron acceleration using an optically generated single cycle THz pulse centered at 0.45 THz. 7 keV of acceleration is achieved using 10 microJ THz pulses in a 3 mm interaction length. The THz pulse is produced via optical rectification of a 1.2 mJ, 1 micron laser pulse with a 1 kHz repetition rate. The THz pulse is coupled into a dielectric-loaded circular waveguide with 10 MeV/m on-axis accelerating gradient. A 25 fC input electron bunch is produced with a 60 keV DC photo-emitting cathode. The achievable accelerating gradient in the THz structures being investigated will scale rapidly by increasing the IR pulse energy (100 mJ - 1 J) and correspondingly the THz pulse energy. Additionally, with recent advances in the generation of THz pulses via optical rectification, in particular improvements to efficiency and generation of multi-cycle pulses, GeV/m accelerating gradients could be achieved. An ultra-compact high-gradient THz accelerator would be of interest for a wide variety of applications.
	Slides WEOAB03 [7.185 MB]
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WEYB01	Large Dynamic Range Beam Diagnostics for High Average Current Electron LINACs	diagnostics, FEL, brightness, optics	1900
	P.E. Evtushenko JLab, Newport News, Virginia, USA
	A number of applications is envisioned now for CW electron LINACs with high average current. A few examples are: driver-accelerators for the next generation of high average brightness SR sources, energy recovery LINACs to be used for frontier research in particle physics - search for dark matter candidate particles, industrial and defense applications. An average beam power of MWs is considered for such applications. Such machines will be required to operate simultaneously with high beam power and peak brightness comparable to the brightest electron beams generated in pulsed LINACs. Combining the high current advantages of storage rings and high peak brightness of LINACs will require such understanding and control of the beam dynamics that 10^-6 fraction of the beam current is taken in to account and controlled during the beam tuning. To make this possible a number of large dynamic range (LDR) (~10⁺⁶) beam diagnostics is under development and test at JLab FEL. Transverse and longitudinal LDR beam profile measurements can be used for LDR measurements of the phase space distribution and its evolution through the accelerator.
	Slides WEYB01 [4.581 MB]
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WEIB02	RF Sub-Systems for Cargo and Vehicle Inspection	detector, photon, vacuum, scattering	1917
	D.J. Mistry, T.A. Cross, C.R. Weatherup e2v, Chelmsford, Essex, United Kingdom
	X-ray screening for security is a well-established inspection technique. Whilst in terms of fielded systems the vast majority consist of low energy X-ray sources, typically used for hand baggage or mail screening. There is a smaller but high value niche market servicing the requirements for border security, and cargo and vehicle inspection (CVI). This latter application requires higher X-ray energies of up to 10 MeV using an electron linear accelerator (linac) source to penetrate fully loaded shipping containers. Increasingly, methods are required to improve throughput and provide a higher level of material discrimination during inspection. This paper will briefly review the elements required to make an effective X-ray source, whilst outlining the RF technology required to drive a linac-based X-ray security system. Following this, potential new developments in radiofrequency (RF) sub-systems will be discussed in the context of user benefits. Abstract redrafted 10.6.14 Original abstract: redrafted 6.12.13. 'The purpose of this presentation is to provide an understanding of global industry security systems and the role of accelerators…'
	Slides WEIB02 [5.892 MB]
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WEPRO005	Development of Superconducting Spoke Cavity for Laser Compton Scattered Photon Sources	cavity, HOM, brightness, photon	1946
	M. Sawamura, R. Hajima, R. Nagai JAEA, Ibaraki-ken, Japan H. Fujisawa, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan T. Kubo KEK, Ibaraki, Japan
	Funding: This work is supported by Photon and Quantum Basic Research Coordinated Development Program. We have launched a 5-year research program to develop superconducting spoke cavity for laser Compton scattered (LCS) photon sources. For realizing a wide use of LCS X-ray and gamma-ray sources in academic and industrial applications, we adopt 325-MHz superconducting spoke cavity to electron beam drivers for the LCS sources. The spoke cavity, originally invented for ion and proton acceleration, can be used for electron accelerators, in which we can make best use of features of spoke cavity: relative compactness in comparison with a TM cavity of the same frequency, robustness with respect to manufacturing inaccuracy due to its strong cell-to-cell coupling, couplers on outer conductor for the better packing in a linac, and so on. In this paper, we present our research plan and results of cavity shape optimization.
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WEPRO007	Nanometer Scale Coherent Current Modulation via a Nanotip Cathode Array and Emittance Exchange	electron, emittance, cavity, gun	1952
	E.A. Nanni, W.S. Graves MIT, Cambridge, Massachusetts, USA P. Piot Fermilab, Batavia, Illinois, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: NSF DMR-1042342, DARPA N66001-11-1-4192 We present PIC simulations of electron bunches with nm scale longitudinal modulation produced using a compact 2-20 MeV LINAC. The modulation is initially imparted in the transverse dimension of the electron bunch with a nano-patterned photo-emitter in a X-band RF gun with 2 MeV exit energy. The electron bunch passes through a 1 m standing wave X-band LINAC which can raise the beam energy up to 20 MeV. The transverse modulation is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. The modulation pitch can be tuned by adjusting the spacing of the nano-patterned photo-emitter or magnification of the transverse pitch with electron optics. The electron beam parameters are optimized to produce coherent XFEL radiation upon interacting with a “laser undulator”.
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WEPRO008	A Beam-driven Microwave Undulator for FEL	undulator, wakefield, electron, FEL	1956
	A. Kanareykin, C.-J. Jing, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia A. Zholents ANL, Argonne, Ilinois, USA
	Funding: DOE SBIR Microwave waveguides can in principle be used for undulators with periods less than 1 cm. Intensive work has been done on the recently proposed design that operates at the HE11 hybrid mode of a corrugated waveguide; successful experimental results have been reported recently [S.Tantawi Talk at POSIPOL 2012]. In this presentation we propose a beam driven design for an undulator based on an electron bunch train powering a microwave or mm waveguide. The drive bunch train propagates towards the undulating beam inside a dielectric loaded structure or corrugated waveguide generating high power RF. The “smart” waveguide design and a proper bunch spacing of the electron drive beam train provide single mode generation of the high magnitude undulating field that gives an undulator parameter in the range of K~1 for a high frequency device.* *A. Zholents, HBEB Workshop, Puerto-Rico, 2013.
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WEPRO015	RF Injector Beam Dynamics Optimization for LCLS-II	emittance, simulation, brightness, cathode	1974
	C. F. Papadopoulos, D. Filippetto, F. Sannibale LBNL, Berkeley, California, USA P. Emma, T.O. Raubenheimer, J.F. Schmerge, L. Wang, F. Zhou SLAC, Menlo Park, California, USA
	Funding: This work was supported in part by the Work supported, in part, by the LCLS-II Project and by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 LCLS-II is a proposal for a high repetition rate (>1 MHz) FEL, based on a CW, superconducting linac. The LCLS-II injector is being optimized by a collaboration from Cornell University, Fermilab, LBNL, and SLAC. There are a number of different possible technical choices for the injector including an rf gun or a high voltage DC gun. In this paper we present the status of the simulations for the injector optimization for an rf gun choice for LCLS-II. A multiobjective genetic optimizer is implemented for this reason, and optimized solutions for different bunch charges, corresponding to different operating modes, are presented. These operating points are also the initial part of the start-to-end simulations for LCLS-II. Finally, we discuss the trade-offs between compression and brightness conservation in the low energy (<100 MeV) part of the accelerator, as well as the status of sensitivity studies.
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WEPRO018	Theoretical Maximum Current of the NSLS-II Linac	simulation, beam-loading, cavity, gun	1980
	R.P. Fliller, F. Gao, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. An analysis of the maximum available NSLS-II linac current was performed as part of the preparation for NSLS-II Booster commissioning. The analysis was necessary in order to establish the maximum beam current available from the linac and the maximum current that would be available to the booster accelerator. In this paper we discuss the assumptions that were used in determining the maximum linac current, the model of the linac and comparison to operational conditions.
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WEPRO019	Comparison of the NSLS-II Linac Model to Measurements	cathode, emittance, simulation, gun	1983
	R.P. Fliller BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy The NSLS-II linac and associated transport lines were successfully installed and commissioned in the spring of 2012. Various beam measurements were performed to ensure that the linac met specifications and would be a suitable injector for the NSLS-II booster. In this paper we discuss the outcomes of these measurements and compare them to the model of the NSLS-II linac.
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WEPRO022	Modal Analysis of Helical Undulator Radiation In Cylindrical Waveguide	radiation, undulator, vacuum, FEL	1989
	T.L. Vardanyan, M. Ivanyan, V. Sahakyan, A.V. Tsakanian, G.S. Zanyan CANDLE SRI, Yerevan, Armenia
	The coherent radiation of the relativistic electron beam with helical orbit in circular waveguide is studied. The radiation field configuration is obtained using modal expansion technique. For short electron bunches the coherent part of radiation is evaluated. The coherent radiation effects on the bunch performance are analyzed.
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Paper

Title

Other Keywords

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MOYBA01

The Very High Intensity Future

target, ion, proton, heavy-ion

17

J. Wei
FRIB, East Lansing, Michigan, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
This paper surveys the key technologies and design challenges that form a basis for the next generation of very high intensity hadron accelerators, including projects operating, under construction, and under design for science and applications at MW beam power level.

Slides MOYBA01 [7.187 MB]

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MOYBA02

New Design Approaches for High Intensity Superconducting Linacs – The New ESS Linac Design

cryomodule, cavity, klystron, emittance

23

D.P. McGinnis
ESS, Lund, Sweden

The cost of the next generation of high intensity accelerators has become so large that no single institution can solely afford to fund the construction of the project. To fund these large projects, institutions have embarked on forming ambitious collaboration structures with other laboratories. To induce other laboratories to join the collaboration, compromises must be made in the accelerator technical design to offer interesting and challenging projects to partner institutions. The cost of high intensity hadron accelerators is largely driven by RF system. A new design philosophy different from the traditional approach is emerging for the high intensity frontier machines. Emittance preservation is often less of an issue as long as beam losses are kept low. At ESS modifications were introduced to the linac design. One of the major changes is the reduction of final energy and an increase of gradient and beam current. As a result the design now meets the cost objective but for the price of a higher risk. The accelerator system designer must then try to balance the cost and technical risks while also satisfying the interests and external goals of the partner laboratories.

Slides MOYBA02 [2.277 MB]

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MOZA02

Advanced RF Design and Tuning Methods of RFQ for High Intensity Proton Linacs

rfq, coupling, dipole, operation

34

A. France
CEA/IRFU, Gif-sur-Yvette, France

The injector of high intensity linacs includes a Radio Frequency Quadrupole (RFQ) which must sustain high surface fields and thermal effects while accelerating intense low energy beams. For this purpose, the modelisation, realisation and tuning of accurate field laws is mandatory to preserve beam emittances and minimize beam losses. This presentation reviews the progress of advanced methods for the RF design, RF measurements during fabrication and final tuning of RFQ for high intensity linacs. It reports the ongoing developments on the injectors of high intensity demonstrators and of the linacs under construction such as SPIRAL2, LINAC4 or IFMIF-EVEDA.

Slides MOZA02 [2.026 MB]

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MOPRO001

Upgrade Status of Injector LINAC for SuperKEKB

positron, electron, emittance, gun

59

T. Miura, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, R. Ichimiya, N. Iida, M. Ikeda, E. Kadokura, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takenaka, M. Tanaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

The SuperKEKB collider is under construction to achieve 40-times higher luminosity than that of previous KEKB collider. The injector LINAC should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron for SuperKEKB based on a nano-beam scheme. A photocathode RF-gun for low emittance electron beam has been already installed and the commissioning has started. The construction of positron capture section using a flux-concentrator and the dumping ring for low emittance positron beam is in progress. The simultaneous top-up injections to four storage-rings including photon factories is also required. In the upstream of dumping ring, the compatible optics between positron and electron has been designed. In the downstream of dumping ring, RF phase, focusing, and steering magnets will be switched by pulse to pulse against each beam-mode for optimising beam-transportation. This paper describes recent upgrade status toward the SuperKEKB.

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MOPRO003

Towards Stable Acceleration in Linacs

klystron, acceleration, bunching, electron

65

A. Dubrovskiy
Private Address, Geneve, Switzerland

Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

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MOPRO012

Simulating Fast Beam-Ion Instability Studies in FFAG-Based ERHIc Rings

electron, ion, simulation, lattice

83

G. Wang, V. Litvinenko, Y. Luo
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In an electron accelerator, ions generated from the residual gas by the circulating electrons act back to the trailing electrons. Under unfavorable conditions this feed-back can cause unstable motion of the electron bunches, the process known as the fast beam ion instability. Current eRHIC design has two FFAG rings transporting 21 electron beams at 11 different energies. In this study, we use numerical simulation to investigate the fast ion instability in this complicated system, compare the simulation results with theory and discuss possible measures to mitigate the instability.

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MOPRO034

Studies on Nonlinear Post-linac Protection for CLIC

sextupole, collimation, luminosity, octupole

148

J. Resta-López
Cockcroft Institute, Warrington, Cheshire, United Kingdom
S.T. Boogert, J. Snuverink
JAI, Egham, Surrey, United Kingdom
A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain

The post-linac energy collimation system of CLIC is designed to fulfill an essential function of protection of the Beam Delivery System (BDS) against miss-steered beams generated by failure modes in the main linac. Guaranteeing the collimator survivability in case of direct beam impact is very challenging, if we take into account the need to deal with an unprecedented transverse beam energy density per beam of the order of GJ/mm². This translates into a high damage potential of uncontrolled beams. In this paper we present an alternative nonlinear energy collimation system as a potential solution to guarantee the survival of the collimators. The performance and error tolerances of this system are studied by means of beam tracking simulations, and compared with those of the conventional baseline CLIC energy collimation system.

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MOPRO066

Status of FLUTE

laser, gun, electron, diagnostics

231

M. Schuh, I. Birkel, A. Borysenko, A. Böhm, N. Hiller, E. Huttel, S. Höninger, V. Judin, S. Marsching, A.-S. Müller, A.-S. Müller, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schwarz, M. Weber, P. Wesolowski
KIT, Karlsruhe, Germany
R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb
DESY, Hamburg, Germany
H.-H. Braun, R. Ganter, V. Schlott, L. Stingelin
PSI, Villigen PSI, Switzerland

FLUTE, a new linac-based test facility and THz source is currently being built at the Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It consists of an RF photo gun and a traveling wave linac accelerating electrons to beam energies of ~41 MeV in the charge range from a few pC up to 3 nC. The electron bunch will then be compressed in a magnetic chicane in the range of 1 - 300 fs, depending on the charge, in order to generate coherent THz radiation with high peak power. An overview of the simulation and hardware status is given in this contribution.

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MOPRO078

The SPARC_LAB Thomson Source Commissioning

electron, laser, photon, emittance

267

C. Vaccarezza, D. Alesini, M.P. Anania, M. Bellaveglia, E. Chiadroni, D. Di Giovenale, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, R. Pompili, S. Romeo, F. Villa
INFN/LNF, Frascati (Roma), Italy
A. Bacci, C. Curatolo, D.T. Palmer, V. Petrillo, A.R. Rossi, L. Serafini, P. Tomassini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
P. Cardarelli, G. Di Domenico, M. Gambaccini
INFN-Ferrara, Ferrara, Italy
A. Cianchi
INFN-Roma II, Roma, Italy
P. Delogu
INFN-Pisa, Pisa, Italy
F. Filippi, A. Giribono
INFN-Roma, Roma, Italy
B. Golosio, P. Oliva
INFN-Cagliari, Monserrato (Cagliari), Italy
A. Mostacci
Rome University La Sapienza, Roma, Italy

The SPARC_LAB Thomson source is presently under commissioning at LNF. An electron beam of energy between 30-150 MeV collides head-on with the laser pulse provided by the Ti:Sapphire laser FLAME, characterized in this phase by a length of 6 ps FWHM and by an energy ranging between 1 and 5 J. The key features of this system are the wide range of tunability of the X-rays yield energy, i.e. 20-500 keV, and the availability of a coupled quadrupole and solenoid focusing system, allowing to reach an electron beam size of 10-20 microns at the interaction point. The experimental results obtained in the February 2014 shifts are presented.

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MOPRO106

Status of the HZB ERL Prototype BERLinPro

gun, cavity, SRF, booster

340

M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, A. Burrill, V. Dürr, A. Jankowiak, C. Kalus, T. Kamps, G. Klemz, J. Knobloch, J. Kolbe, O. Kugeler, B.C. Kuske, A.N. Matveenko, A. Meseck, A. Neumann, K. Ott, E. Panofski, D. Pflückhahn, J. Rahn, J. Rudolph, M. Schmeißer, S.G. Schubert, O. Schüler, J. Völker, S. Wesch
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association.
The Berlin Energy Recovery Linac Prototype BERLinPro is to be constructed at the Helmholtz Zentrum site in Berlin. The aim of the project is to expand the required accelerator physics and technology knowledge mandatory for the generation of a high current (100 mA), high brilliance (norm. emittance below 1 mm mrad) cw electron beam. Since the funding decision in October 2010 the project has entered a phase of detailed planning. Hardware specifications have been defined and various components have been ordered. Furthermore, extensive tests of principal superconducting accelerator components successfully demonstrated the envisaged hardware performance. A summary of the most recent activities together with the details of the project timeline for the coming years are given in this paper.

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MOPRO107

Multi-turn ERL-based Synchrotron Light Facility: Injector Design

emittance, gun, brilliance, booster

343

A.N. Matveenko, T. Atkinson, A.V. Bondarenko, Y. Petenev
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association VH NG 636 and HRJRG-214
Multi-turn energy recovery linac based light sources are candidates for the future 4th generation synchrotron light sources. Using the superconducting linac technology, the Femto-Science-Factory (FSF) will provide its users with ultra-bright photon beams of angstrom wavelength at 6 GeV final beam energy. The FSF is intended to be a multi-user facility and offers a variety of operation modes. An overview of the machine layout and magnetic optics design of the installation will be given in this paper with the focus on high brightness injector design.

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MOPRO108

Lattice and Start-to-end Simulation of the Mainz Energy Recovering Superconducting Accelerator MESA

lattice, experiment, simulation, optics

346

R.G. Heine, K. Aulenbacher, F. Schlander, D. Simon
IKP, Mainz, Germany

Funding: work supported by the German Federal Ministery of Education and Research under the Cluster of Excellence "PRISMA"
The institute for nuclear physics (IKPH) at Mainz University is designing a multi turn energy recovery linac for particle physics experiments *. We present the current status of the lattice development of MESA together with a PARMELA start to end simulation.
* R. Heine, K. Aulenbacher, and R. Eichhorn: MESA-Sketch of an Energy Recovery LINAC for Nuclear Physics Experiments at Mainz, Proc. of the IPAC2012, New Orleans, Louisiana, USA, p. 1993-1995.

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MOPRO110

Present Status of the Compact ERL at KEK

recirculation, laser, dipole, injection

353

N. Nakamura, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sakanaka, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, O. Tanaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
JAEA, Ibaraki-ken, Japan
J.G. Hwang
KNU, Deagu, Republic of Korea
M. Kuriki
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
Y. Seimiya
HU/AdSM, Higashi-Hiroshima, Japan

The Compact Energy Recovery Linac (cERL) project is ongoing at KEK in order to demonstrate excellent ERL performance as a future light source. The cERL injector was already constructed with its diagnostic beamline and successfully commissioned from April to June in 2013. In the next step, the cERL recirculation loop with a main superconducting linac and merger and dump sections has been constructed and its commissioning is scheduled to start in December 2013. Significant progress is expected by the IPAC14 conference date. In this presentation, we will describe the present status of the cERL including future developments.

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MOPRO112

Energy Recovering for Linac RF Injectors

cavity, gun, SRF, HOM

356

V. Volkov, Ya.V. Getmanov, O.A. Shevchenko, N. Vinokurov
BINP SB RAS, Novosibirsk, Russia
A.N. Matveenko
HZB, Berlin, Germany

The article presents a new design of a CW RF high average current superconducting injector cavity. This design allows recovering energy in the injector, improving beam parameters and energy efficiency, reducing injector size, cost, and avoiding high average power coupler problem.

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MOPRO113

Beam-based HOM Measurements in Cornell's ERL Main Linac Cavity

HOM, cavity, dipole, quadrupole

359

D.L. Hall, A.C. Bartnik, M.G. Billing, D. Gonnella, G.H. Hoffstaetter, M. Liepe, C.E. Mayes
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

A search for HOMs in Cornell’s ERL main linac cavity installed in a Horizontal Test Cryomodule (HTC) has been carried out using a bunch charge modulation method, as part of the effort towards building an Energy Recovery Linac (ERL). The beam-based HOM measurements offer the significant advantage of being able to detect trapped modes invisible to both the RF pickup probes and HOM damping loads, and allow for measuring the R/Q of the modes. For each HOM detected during the search, measurements were taken to determine its nature (monopole, dipole, etc.), frequency, loaded quality factor and shunt impedance. A selection of the most notable modes found is presented, compared to 3D HOM simulations, and their potential impact on the BBU current of the future Cornell ERL is discussed.

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MOPRO115

A Low Energy Electron-Scrapersystem for the S-DALINAC Injector

electron, acceleration, controls, target

366

L.E. Jürgensen, T. Bahlo, C. Burandt, F. Hug, T. Kürzeder, N. Pietralla, T. Schösser, C. Ungethüm
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG through SFB 634
The S-DALINAC is the superconducting linear accelerator of the Institut für Kernphysik at Technische Universität Darmstadt. It delivers an electron beam with energies up to 130 MeV. In order to improve the energy spread and the energy stability of the beam for further acceleration a new scrapersystem has been developed and installed between the 10 MeV injector and the main linac. The system was designed to ensure an energy spread of dE < 10^-03. After installation several tests have taken place, the results will be presented in this work.

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MOPME004

RFQ Solver based on the Method of Moments

rfq, simulation, impedance, quadrupole

382

C. Raucy, C.V.G. Craeye
UCL, Louvain-la-Neuve, Belgium
D. Vandeplassche
SCK•CEN, Mol, Belgium

Funding: SCK•CEN
The aim of this research is to improve the accuracy and the simulation time of solvers devoted to Radio Frequency Quadrupoles (RFQ). The Method of Moments is a full-wave method used to solve scattering problems. Its main advantage over FE or FDTD solvers is that unknowns are limited to the boundaries of the object. The resulting dense system of equations can be solved very rapidly with the help of domain-decomposition approaches (e.g. Macro Basis Functions*), especially when the level of detail is very fine compared to the wavelength, which is definitely the case for RFQ’s. Such a method however needs a first regularization method to overcome the low-frequency breakdown in order to compute the Macro Basis Functions. The respective field contributions of different parts of the global structure (e.g. rods vs. stems) can also easily be finely investigated. Numerical results will be presented based on the Myrrha RFQ. The low-frequency breakdown issue due to the very fine mesh will be discussed and a solution based on the so-called Loop-Tree** decomposition will be detailed.
* Ozdemir, N.A.; Gonzalez-Ovejero, D.; Craeye, C., IEEE Tr.AP, vol.61, no.4, pp.2088, 2098, April 2013
** Andriulli, F.P., IEEE Tr.AP, vol.60, no.5, pp.2347, 2356, May 2012

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MOPME017

Study of Higher Order Modes in Multi-Cell Cavities for BESSY-VSR Upgrade

cavity, HOM, SRF, dipole

412

T. Galek, K. Brackebusch, Sh. Gorgi Zadeh, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Work supported by Federal Ministry for Research and Education BMBF under contract 05K13HR1.
BESSY-VSR is a planned scheme to upgrade the existing BESSY II storage ring to support variable electron pulse lengths. In addition to the present 0.5 GHz energy replenishment cavity, two additional SRF bunch compressing cavities operating at 1.5 GHz (3rd harmonic) and 1.75 GHz (sub-harmonic), will be installed. These cavities are essential to produce short 1.5 ps bunches with current of up to 0.8 mA per bunch. In order to achieve such high beam currents, higher order modes must be damped in the superconducting cavities. In this work we present analysis of higher order modes in cavities with different mid-cell shapes.

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MOPME018

Quantification of Geometric Uncertainties in Single Cell Cavities for BESSY VSR using Polynomial Chaos

cavity, simulation, HOM, SRF

415

J. Heller, T. Flisgen, C. Schmidt, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Federal Ministry for Research and Education Germany under contract 05K13HR1
The electromagnetic properties of SRF cavities are mostly determined by their shape. Due to fabrication tolerances, tuning and limited resolution of measurement systems, the exact shape remains uncertain. In order to make assessments for the real life behaviour it is important to quantify how these geometrical uncertainties propagate through the mathematical system and influence certain electromagnetic properties, like the resonant frequencies of the structure's eigenmodes. This can be done by using non-intrusive straightforward methods like Monte-Carlo (MC) simulations. However, such simulations require a large number of deterministic problem solutions to obtain a sufficient accuracy. In order to avoid this scaling behaviour, the so-called polynomial chaos (PC) expansion is used. This technique allows for the relatively fast computation of uncertainty propagation for few uncertain parameters in the case of computationally expensive deterministic models. In this paper we use the PC expansion to quantify the propagation of uncertain geometry on the example of single cell cavities used for BESSY VSR as well as to compare the obtained results with the MC simulation.

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MOPME032

PIC Simulations in Low Energy Part of PIP-II Proton Linac

rfq, simulation, emittance, proton

448

G.V. Romanov
Fermilab, Batavia, Illinois, USA

The front end of PIP-II linac is composed of a 30 keV ion source, low energy beam transport line (LEBT), 2.1 MeV radio frequency quadrupole (RFQ), and medium energy beam transport line (MEBT). This configuration is currently being assembled at Fermilab to support a complete systems test. The front end represents the primary technical risk with PIP-II, and so this step will validate the concept and demonstrate that the hardware can meet the specified requirements. SC accelerating cavities right after MEBT require high quality and well defined beam after RFQ to avoid excessive particle losses. In this paper we will present recent progress of beam dynamic study, using CST PIC simulation code, to investigate partial neutralization effect in LEBT, halo and tail formation in RFQ, total emittance growth and beam losses along low energy part of the linac.

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MOPME035

Current Status of the GPU-Accelerated ELEGANT

GPU, operation, simulation, acceleration

454

I.V. Pogorelov, K.M. Amyx, J.R. King
Tech-X, Boulder, Colorado, USA
M. Borland, R. Soliday
ANL, Argonne, Ilinois, USA

Funding: Work supported by the DOE Office of Science, Office of Basic Energy Sciences grant No. DE-SC0004585, and in part by Tech-X Corporation.
Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale tracking simulations. This presentation is an update on the current status of our work on accelerating Argonne National Lab’s particle accelerator simulation code ELEGANT using CUDA-enabled GPU. We summarize the performance of beamline elements ported to GPU, and discuss optimization techniques for some important collective effects kernels, in particular our methods of avoiding costly thread contention. We also present preliminary results of a scaling study of the GPU-accelerated version of the code.

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MOPME046

Supervision Software for the Integration of the Beam Interlock System with the CERN Accelerator Complex

software, operation, monitoring, hardware

476

M. Audrain, D. Anderson, M. Dragu, K. Fuchsberger, J.C. Garnier, A.A. Gorzawski, M. Koza, K.H. Krol, A. Moscatelli, B. Puccio, K. Stamos, M. Zerlauth
CERN, Geneva, Switzerland

The Accelerator complex at the European Organisation for Nuclear Research (CERN) is composed of many systems which are required to function in a valid state to ensure safe beam operation. One key component of machine protection, the Beam Interlock System (BIS), was designed to interface critical systems around the accelerator chain, provide fast and reliable transmission of beam dump requests and trigger beam extraction in case of malfunctioning of equipment systems or beam losses. Numerous upgrades of accelerator and controls components during the Long Shutdown 1 (LS1) are followed by subsequent software updates that need to be thoroughly validated before the restart of beam operation in 2015. In parallel, the ongoing deployments of the BIS hardware in the PS booster (PSB) and the future LINAC4 give rise to new requirements for the related controls and monitoring software due to their fast cycle times. This paper describes the current status and ongoing work as well as the long-term vision for the integration of the Beam Interlock System software into the operational environment.

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MOPME059

Design of a Multi-harmonic Buncher for LINCE

ion, rfq, bunching, operation

508

J. Labrador, C. Bonțoiu, J.A. Dueñas, I. Martel
University of Huelva, Huelva, Spain
M.A. Carrera, A. Garbayo
AVS, Elgoibar, Spain
A.C.C. Villari
FRIB, East Lansing, Michigan, USA

Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
Continuous beams delivered by the LINCE ECR ion source will be bunched by a multi-harmonic buncher consisting of two copper-made electrodes. Its numerical design is reported here along with electric and magnetic field maps. Multi-frequency operation is proven by tracking a continuous beam and optimizing the its longitudinal phase space bunching for various ion species under the influence of space charge effects. A thermo-mechanical study carried out in order to estimate the needed water flow through the electrodes is presented as well.

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MOPRI002

Design, Manufacture and Operation of the Beam Spoiler for Positron Target Protection

target, positron, electron, alignment

573

L. Zang, K. Kakihara, T. Kamitani, K. Mikawa, F. Miyahara, T. Suwada
KEK, Ibaraki, Japan

In order to produce positrons, intensive pulsed electron beam is used to strike on a tungsten target. The energy deposition is distributed non-uniformly over the target, leading to a mechanical stress. As a result of large thermal gradient, the target could be potentially damaged. To avoid the target destruction, the peak energy deposition density (PEDD) in the target should be well below the critical limit (35J/g) based on the SLAC operational experience. With an expected primary electron spot size on the target of the SuperKEKB positron source, the PEDD will exceeds the limit. We will introduce a beam spoiler to enlarge the spot size by multiple scattering in thin beam screen and aluminum plate. It reduces the PEDD down to half of the limit. This paper describes the design of the spoiler and the beam screen system used in the positron beam commissioning of the SuperKEKB positron source started in 2014.

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MOPRI036

Pulse Radiolysis Using Terahertz Probe Pulses

electron, laser, radiation, gun

676

K. Kan, M. Gohdo, T. Kondoh, K. Norizawa, I. Nozawa, A. Ogata, T. Toigawa, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Pulse radiolysis, which utilizes a pump electron beam and a probe pulse, is a powerful tool that can be used for the time-resolved observation of ultrafast radiation-induced phenomena. Recently, double-decker pulse radiolysis* using visible probe pulses were demonstrated based on a photocathode RF gun driven by two UV pulses, which enabled synchronized pump electron beam and visible probe pulses. In this study, pulse radiolysis using terahertz (THz) probe pulses which were realized by the “double-decker” electron beams and dynamics of transient quasi-free electrons in semiconductors are presented.
* K. Kan et al., Rev. Sci. Instrum. 83, 073302 (2012).

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MOPRI037

Development of Iridium Cerium Photocathode for the Generation of High-Charge Electron Beam

laser, electron, cathode, gun

679

D. Satoh
TIT, Tokyo, Japan
N. Hayashizaki
RLNR, Tokyo, Japan
T. Natsui, M. Yoshida
KEK, Ibaraki, Japan

We developed an iridium cerium cathode material made by new production method for multi-purpose electron source. For multi-purpose electron source, we focused on the Ir5Ce compound which has a high melting point (> 2100 K) and a low work function (2.57 eV). This material has some excellent properties as both a thermionic cathode and a photocathode. For example, Ir5Ce thermionic cathode can generate one-order higher electrical current than a LaB6 cathode at the same temperature. Another advantage is that an Ir5Ce thermionic cathode has a lifetime two orders longer than that of a LaB6 thermionic cathode under the same conditions. Moreover, we discovered that this material has a reasonably high quantum efficiency (2.70 × 10−3 @213nm at 1000°C) and long-lifetime (> LaB6) as a photocathode. Our research shows that Ir5Ce compound is optimum material for a thermionic cathode and photocathode. We focused on this good emission properties under the high temperature and we tried to develop a backside electron beam heating system and demonstrate a laser pre-pulse heating for a high current thermionic gun system or high charge photocathode gun.

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MOPRI054

Status of the APEX Project at LBNL

gun, cathode, cavity, FEL

727

F. Sannibale, K.M. Baptiste, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J.A. Doyle, D. Filippetto, G.L. Harris, G. Huang, H. Huang, R. Huang, T.D. Kramasz, S. Kwiatkowski, R.E. Lellinger, V. Moroz, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, J.W. Staples, M. Vinco, S.P. Virostek, R.P. Wells, M.S. Zolotorev
LBNL, Berkeley, California, USA
R. Huang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
The Advanced Photo-injector EXperiment (APEX) at the Lawrence Berkeley National Laboratory (LBNL), consists in the development of an injector designed to demonstrate the capability of the VHF gun, a normal conducting 186 MHz RF gun operating in CW mode, to deliver the brightness required by X-ray FEL applications at MHz repetition rate. APEX is organized in 3 main phases where different aspects of the required performance are gradually demonstrated. The status and future plans for the project are presented.

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MOPRI082

Acceleration of High-Intensity Heavy-Ion Beams at RIKEN RI Beam Factory

ion, ion-source, cyclotron, ECRIS

800

O. Kamigaito, T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, T. Nakagawa, M. Nakamura, J. Ohnishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, T. Watanabe, Y. Watanabe, K. Yamada, H. Yamasawa
RIKEN Nishina Center, Wako, Japan
T. Nagatomo
RIKEN, Saitama, Japan

Recent efforts concerning the RIBF accelerators in RIKEN have been directed towards achieving higher beam intensities of very heavy ions such as uranium and xenon. As presented in the last IPAC conference in 2013, the intensities of these ion beams have significantly improved due to the construction of a new injector, RILAC2, which is equipped with a 28-GHz superconducting ECR ion source, the development of a helium gas stripper, and upgrading of the bending power of the fRC. In this light, this paper presents the subsequent upgrade programs carried out in the last couple of years, such as developments of a new air stripper for xenon beams and a micro-oven for metallic ions. The current performance level of the RIBF accelerator complex, as well as a future plan to further increase the beam intensities, are also presented.

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MOPRI090

Beam Distribution Transformation with SFMs at 3MeV C-ADS Beamline

target, beam-transport, quadrupole, rfq

824

H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The C-ADS project is building a test facility at the Institute of High Energy Physics. The design goal of the test facility is 10MeV beam energy with a continuous beam current of 10mA. To sustain the 100kW CW beam power at the beam dump, a beam distribution transform system is designed. The Step Field Magnets (SFMs) are used to transform the beam distribution from Gaussian to uniform. In this test stand, two sets of SFMs will be employed to manipulate the beam distribution. At the first commissioning stage, the bump dump line will be connected to the Medium Energy Beam Transport-1 (MEBT1) to test the beam manipulation scheme. The design and error analysis of this 3MeV beam dump line will be discussed in this paper.

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MOPRI103

Longitudinal Bunch Shortening for the Laser Stripping Project

laser, cavity, focusing, acceleration

861

T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, V.V. Danilov, Y. Liu, M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation.
Realization of high efficiency laser stripping at the SNS accelerator needs good longitudinal overlap between H⁻ bunch and laser pulse. The default H⁻ bunch length at the interaction point is 5 times bigger than needed in order to achieve 90% stripping efficiency. Theoretical and experimental studies of longitudinal H⁻ bunch shortening are presented in this paper.

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MOPRI108

Transverse H⁻ Beam Halo Scraper System in the J-PARC L3BT

radiation, injection, proton, operation

876

K. Okabe, M. Kinsho, K. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-mura, Japan

In the Japan Proton Accelerator Research Complex (J-PARC) 3-GeV rapid cycle synchrotron (RCS), transverse beam halo scraping for the injection beam is required to increase the output beam power. The transverse collimation system at the Linac-RCS beam transport line (L3BT) was utilized in a nominal beam operation because the area of the scraper section was contaminated when scrapers were working. In the summer-autumn period of 2013, we installed a new beam-halo scraper which had optimized scraper heads for mitigation of the radiation around the scraper system. In this poster, we report a preliminary result for a halo scraper at the L3BT.

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TUXA01

Commissioning the 400 MeV Linac at J-PARC and High Intensity Operation of the J-PARC RCS

injection, dipole, emittance, operation

899

H. Hotchi
JAEA/J-PARC, Tokai-mura, Japan

J-PARC is currently upgrading their linac from 181MeV to 400 MEV with a new ACS section (annular coupled structure). This includes a triple frequency jump, and there should be some interesting results to report. As the result of the injector linac upgrade at J-PARC, the Rapid Cycle Synchrotron (RCS) will achieve a record-high intensity as a proton accelerator. This talk describes the recent performance of the RCS together with its beam-dynamical issues.

Slides TUXA01 [3.611 MB]

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TUOBA02

Design Study of an ERL Test Facility at CERN

electron, cryomodule, cavity, optics

921

E. Jensen, C. Bracco, O.S. Brüning, R. Calaga, N. Catalán Lasheras, B. Goddard, R. Torres-Sanchez, A. Valloni
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The modern concept of an Energy Recovery Linac allows providing large electron currents at large beam energy with low power consumption. This concept is used in FEL’s, electron-ion colliders and electron coolers. CERN has started a Design Study of an ERL Test Facility with the purpose of 1) studying the ERL principle, its specific beam dynamics and operational issues, as relevant for LHeC, 2) providing a test bed for superconducting cavity modules, cryogenics and integration, 3) studying beam induced quenches in superconducting magnets and protection methods, 4) providing test beams for detector R&D and other applications. It will be complementary to existing or planned facilities and is fostering international collaboration. The operating frequency of 802 MHz was chosen for performance and for optimum synergy with SPS and LHC; the design of the cryomodule has started. The ERL Test Facility can be constructed in stages from initially 150 MeV to ultimately 1 GeV in 3 passes, with beam currents of up to 80 mA. Parameters to serve the above-mentioned purposes are well defined and possible lattice designs have well advanced.

Slides TUOBA02 [14.419 MB]

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TUZA02

THz Facility at ELBE: A Versatile Test Facility for Electron Bunch Diagnostics on Quasi-CW Electron Beams

electron, diagnostics, SRF, operation

933

M. Gensch, B.W. Green, J. Hauser, S. Kovalev, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig
HZDR, Dresden, Germany
A. Al-Shemmary, V. B. Asgekar, T. Golz, H. Schlarb, N. Stojanovic, S. Vilcins
DESY, Hamburg, Germany
A.S. Fisher
SLAC, Menlo Park, California, USA
G. Geloni
XFEL. EU, Hamburg, Germany
A.-S. Müller, M. Schwarz
KIT, Karlsruhe, Germany
N.E. Neumann, D. Plettemeier
TU Dresden, Dresden, Germany

At the Helmholtz-Zentrum Dresden-Rossendorf near Dresden a quasi-cw low-energy electron linear accelerator based on superconducting radiofrequency technology is operated successfully for more than 10 years. The ELBE accelerator is driving several secondary radiation sources including 2 infrared free electron lasers. A new addition will be a THz facility that aims to make use of super-radiant THz radiation. In its final form the THz facility shall consist of one coherent diffraction radiator and one undulator source which provide high-field THz pulses at unprecedented repetition rates. While the medium term goal is to establish a unique user facility for nonlinear THz science, the THz sources are already used as a test facility for novel diagnostic techniques on quasi-cw electron beams. The progress of the developments is reported and an outlook into future challenges and opportunities is given.

Slides TUZA02 [3.041 MB]

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TUOCA01

The Linac Coherent Light Source-II Project

electron, undulator, cryomodule, laser

935

J.N. Galayda
SLAC, Menlo Park, California, USA

Funding: Work supported by US DOE Contract DE-AC02-766SF00515
The “Linac Coherent Light Source–II” Project, initiated in September 2010, has gone through a radical transformation beginning in August 2013. In its new form, LCLS-II will construct a 4 GeV CW superconducting linac in the first kilometre of the existing linac tunnel. A new undulator, optimized as a soft x-ray (200-1,300 eV) source, will receive electrons from the new SC linac. The existing undulator system will be replaced with a new variable gap device, which will receive electrons from either the new SC linac (providing 1-5 keV photons) or the copper linac presently used by LCLS (providing 1-25 keV x-rays). First light from the new facility is expected in September 2019.
galayda@slac.stanford.edu

Slides TUOCA01 [9.380 MB]

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TUOCA02

Status of the Free Electron Laser User Facility FLASH

FEL, flattop, gun, laser

938

M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch
DESY, Hamburg, Germany

FLASH, the Free Electron Laser User Facility at DESY (Hamburg, Germany), delivers high brilliance XUV and soft X-ray FEL radiation to photon experiments. After a shutdown to connect the second undulator beamline FLASH2 to the FLASH linac, re-commissioning of FLASH started in autumn 2013. The year 2014 is dedicated to FLASH1 user experiments. The commissioning of the FLASH2 beamline takes place in 2014 in parallel to FLASH1 operation.

Slides TUOCA02 [9.156 MB]

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TUPRO036

Start-to-end Optic of the FSF Multi-turn ERL Project

emittance, injection, undulator, simulation

1099

T. Atkinson, A.V. Bondarenko, A.N. Matveenko, Y. Petenev
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association VH NG 636 and HRJRG-214
Advanced magnetic optic designs are required to meet the heavy demands of future light sources: diffraction limited emittance, femto-second pulses and low energy spread. This paper highlights the magnetic optic that is presently being investigated in the ERL-simulation group at HZB. The injector optic is based on subtle emittance compensation techniques of space charge dominated beams. The high energy arcs are designed to suppress emittance growth due to CSR through horizontal phase advance manipulation, ISR effects by keeping the radiation integrals small and reduce the degradation due to chromatic aberrations. Optimised Start-to-End beam dynamic simulations are presented.

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TUPRO038

Beam Positioning Concept and Tolerance Considerations for BERLinPro

laser, emittance, gun, timing

1105

B.C. Kuske, J. Rudolph
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
BERLinPro is an ERL project at Helmholtz-Zentrum Berlin, with the goal to illuminate the challenges and promises of a high brightness 100 mA superconducting RF gun in combination with a 50 MeV return loop and energy recovery [1, 2]. The precision of the beam position in a single turn machine might be relaxed compared to the demands in storage rings. Still, a trajectory correction concept has to be developed and the influence of trajectory offsets on the goal parameters, its dependence on fluctuating injection parameters or effects related to the low energy of 6.5-50 MeV have to be investigated. This paper covers the initial trajectory correction studies and first tolerance scenarios of BERLinPro using the projected hardware concept.

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TUPRO043

Status and Computer Simulations for the Front End of the Proton Injector for Fair

proton, ion, simulation, extraction

1120

C. Ullmann, R. Berezov, J. Fils, R. Hollinger, V. Ivanova, O.K. Kester, W. Vinzenz
GSI, Darmstadt, Germany
N. Chauvin, O. Delferrière
CEA/IRFU, Gif-sur-Yvette, France

FAIR - the international facility for antiproton and ion research – located at GSI in Darmstadt, Germany is one of the largest research projects worldwide. It will provide an antiproton production rate of 7·10¹⁰ cooled pbars per hour, which is equivalent to a primary proton beam current of 2·1016 protons per hour. A high intensity proton linac (p-linac) will be built, with an operating rf-frequency of 325 MHz to accelerate a 70 mA proton beam up to 70 MeV, using conducting crossed-bar H-cavities. The repetition rate is 4 Hz with an ion beam pulse length of 36 μs[1]. Developed within a joint French-German collaboration - GSI/CEA-SACLAY/IAP – the compact proton linac will be injected by a microwave ion source and a low energy beam transport (LEBT). The 2.45 GHz ion source allows high brightness ion beams at an energy of 95 keV and will deliver a proton beam current of 100 mA at the entrance of the RFQ (Radio Frequency Quadrupole) within an emittance of 0.3π mm mrad (rms). To check on these parameters computer simulations with TraceWin, IGUN and IBSIMU of the ion extraction and LEBT (Low Energy Beam Transport) are performed.

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TUPRO044

Bunch Compression of the Low-energy ELBE Electron Beam for Super-radiant THz Sources

radiation, electron, emittance, undulator

1123

U. Lehnert, P. Michel, R. Schurig
HZDR, Dresden, Germany
A.A. Aksoy
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
P.E. Evtushenko
JLab, Newport News, Virginia, USA
J.M. Krämer
Danfysik A/S, Taastrup, Denmark

At the ELBE radiation source two super-radiant THz sources, a broad-band trasnsition/diffraction radiation source and a planar undulator narrow-band sourc are under commissioning. At present the facility is driven from the ELBE linac with a CW electron beam of 100kHz repetition rate and up to 100pC of bunch charge. With the upgraded SRF electron gun bunch charges up to 1nC will become available. For the beam energies in the 20-30 MeV range buch compression into the sub-200 fs range becomes a major challenge. We present beam dynamics calculation of the attempted bunch compression scheme as well as first measurements obtained during the commissioning.

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TUPRO050

Measurements of the Optical Functions at FLASH

optics, quadrupole, controls, coupling

1141

J. Zemella, T. Hellert, M. Scholz, M. Vogt
DESY, Hamburg, Germany

In 2013 the superconducting soft x-ray Free Electron Laser FLASH at DESY (Hamburg, Germany) the extraction section needed to connect the 2nd beam line FLASH2 was installed. In order to allow simultaneous operation of the two beam lines (FLASH1/2), the optical functions in the extraction area needed to be modified. During the recommissioning of FLASH we have optimized, measured and corrected the optical functions in the machine. We report on the the results and the methods.

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TUPRO053

Design and Optimization of Racetrack Microtron for Laser Compton Scattered Gamma-ray Sources

electron, simulation, dipole, injection

1150

R. Hajima
JAEA/ERL, Ibaraki, Japan
M. Ferdows
JAEA, Ibaraki-ken, Japan

Funding: This work is supported by Funds for Integrated Promotion of Social System Reform and Research and Development.
Racetrack microtron (RTM) is a compact accelerator to obtain electron beams with an energy above 100 MeV. Conventional RTM's have been designed to accelerate a train of electron bunch from a thermionic electron gun, where the bunch charge is typically 10 pC. In the industrial application of laser Compton scattered gamma-ray sources, RTM with 200-300 MeV electron energy will be a suitable device to produce 2-3 MeV gamma-ray beams. Single electron bunch from a photocathode RF gun is accelerated and a high-charge small-emittance beam is preferable in such RTM. In this paper, we adopt a simulation code, GPT, for design and optimization of RTM in view of high-charge and small-emittance beam generation.

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TUPRO055

Design Status of the RISP Test Facility LEBT

rfq, ECR, simulation, quadrupole

1156

R.M. Bodenstein, D. Jeon
IBS, Daejeon, Republic of Korea
J. Bahng
Kyungpook National University, Daegu, Republic of Korea

Funding: Supported by the Rare Isotope Science Project of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea Project No. 2011-0032011
Raon, the rare isotope accelerator of the the Rare Isotope Science Project (RISP) in Daejeon, South Korea, is being designed to accelerate multiple-charge-state beams simultaneously. Using an Electron Cyclotron Resonance (ECR) Ion Source to produce the ions, Raon will transport the beam through two 90-degree bending magnets and a Low Energy Beam Transport (LEBT) system to a Radio Frequency Quadrupole (RFQ). In order to test the components of the injector and LEBT system, a test facility is under development. A new LEBT, based upon the LEBT of the main driver linac, is being designed to fit within the test facility’s restrictive space requirements. This work will briefly review the main driver linac LEBT design, and then discuss the current status of the test facility LEBT design.

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TUPRO056

Merit Functions for the Linac Optics Design for Colliders and Light Sources

optics, emittance, focusing, quadrupole

1159

S. Di Mitri, M. Cornacchia
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea

Optics matching and transverse emittance preservation are key goals for a successful operation of modern high brightness electron linacs. The capability of controlling them in a real machine critically relies on a properly designed magnetic lattice. Conscious of this fact, we introduce an ensemble of optical functions* that permit to solve the often neglected conflict between strong focusing, typically implemented to counteract coherent synchrotron radiation and transverse wakefield instability, and distortion of the transverse phase space induced by chromatic aberrations and focusing errors. A numerical evaluation of the merit functions is applied to existing and planned linac-based free electron lasers.
*S. Di Mitri and M. Cornacchia, Nucl. Instr. Meth. Phys. Research A 735, 60–65 (2014).

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TUPRO061

Benchmarking Beam Envelope Models for the European Spallation Source

DTL, simulation, dipole, space-charge

1174

I. List
Cosylab, Ljubljana, Slovenia
E. Laface
ESS, Lund, Sweden

TraceWin is used at the European Spallation Source (ESS) as the design tool, while fast and accurate on-line models will be needed during the operations. Three models are compared: the ESS Linac Simulator (ELS), TraceWin and the OpenXAL. In all of the benchmarked models, dynamics of each beam-line element is, to the first order, represented by a transfer matrix. Differences in the matrices occur, since different reference frames are used and as well different assumptions about the energy of the particles are made. General transformations of the reference frames will be presented. Using those, the comparison of transfer maps among TraceWin and OpenXAL are given. When the differences between TraceWin and OpenXAL were unclear, the benchmark versus other code, like MAD-X and Dynac was done. The best implementations were combined into a new on-line model implementation Java ELS (or JELS) and at last the comparison of the latter with TraceWin is given.

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TUPRO064

Scaling Laws of Wake Field Effects for Gradient Changes in the CLIC Main Linac

wakefield, emittance, simulation, damping

1183

J. Pfingstner, A. Latina, D. Schulte
CERN, Geneva, Switzerland

The main linac of CLIC is designed to maximize the transportable bunch charge, since this parameter determines the energy efficiency of the CLIC accelerating structures. The bunch charge is limited by short-range wake field effects, which increase the projected beam emittance. For the main linac cost optimisation, it is important to understand how the charge limit scales with the change of the gradient of the accelerating structures. In this paper, we determine such a scaling law via simulations studies. It is shown that from different possible scenarios, the charge limit for a lower gradient CLIC structure scales advantageous and a relatively high charge can be used.

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TUPRO065

Tests of Beam-based Alignment at FACET

wakefield, emittance, simulation, alignment

1186

A. Latina, J. Pfingstner, D. Schulte
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

Tests of Beam-Based Alignment have been performed at FACET, with successful results. A flight simulator based on PLACET has been put in place to test the correction algorithms before applying the correction to the real machine. The flight simulator not only helped studying the parameters space in a safe environment, but it also helped developing a graphical interface that the experimenter can use to set each parameter of the correction also during the on-line.

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TUPRO091

Simple Characterization Method of Small High Gradient Permanent Magnet Quadrupoles

quadrupole, proton, focusing, permanent-magnet

1250

C. Ronsivalle, L. Picardi, M. Vadrucci
ENEA C.R. Frascati, Frascati (Roma), Italy
F. Ambrosini
URLS, Rome, Italy

The application of quadrupoles with high or ultra-high gradient and small apertures requires a precise control over harmonic components of the field. A simple, fast, low cost measurement method on small size PMQs (Permanent Magnet Quadrupoles) is described. It is based on the same principle of the familiar "rotating coil technique", but in this case, profiting of the small dimensions of the PMQ, it consists in rotating the PMQ itself instead of the coil. In such way a gain on accuracy and measure time is obtained. It has been applied to characterize a set of commercial PMQs with a gradient around 200 T/m and an internal radius of 3.5 mm to be mounted in a SCDTL (Side Coupled Drift Tube Linac) structure for the acceleration of a proton beam from 7 to 12 MeV. This structure has been developed in the framework of the Italian TOP-IMPLART (Intensity Modulated Proton Linear Accelerator for Radiotherapy) Project

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TUPRO095

Using One-dimensional Hall Probe to Measure the Solenoid Magnet for CSNS/RCS

solenoid, collimation, synchrotron, insertion

1262

Z. Zhang, S. Li, F. Long, X.J. Sun
IHEP, Beijing, People's Republic of China

Abstract CSNS(China Spallation Neutron Source) construction is expected to start in 2010 and will last 6.5 years. A long beam transport line is followed with the DTL linac to send the beam a rapid cycling synchrotron (RCS) accelerator. The beam will be focused by the solenoid magnet. This magnet will be located in LEBT system. It has been used with one-dimensional Hall probe to measurement by Institute of High Energy Physics, China. After the measurement, the measurement results meet the design requirements.

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TUPRO100

Rare-Earth End Magnets of a Miniature Race-Track Microtron and their Tuning

microtron, quadrupole, simulation, permanent-magnet

1277

I.Yu. Vladimirov, N.I. Pakhomov, V.I. Shvedunov
MSU, Moscow, Russia
Yu.A. Kubyshin
UPC, Barcelona, Spain
J.P. Rigla
I3M, Valencia, Spain
V.V. Zakharov
Tehnomag ltd., Kaluga, Russia

We report on the tuning of end magnets of a compact 12 MeV racetrack microtron (RTM) which is under construction at the Technical University of Catalonia. They are magnetic systems composed of four dipoles with the Rare-Earth Permanent Magnet (REPM) material used as a source of the magnetic field. The poles of the magnets are equipped with tuning plungers which allow to adjust the magnetic field level. In the article we describe the tuning procedure and different techniques that were used in order to fulfill strict requirements of the field characteristics of the end magnets. It is shown that the obtained magnetic systems provide correct beam trajectories in the 12 MeV RTM.

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TUPRO104

Design of the Beam Transfer Line Magnets for HIE-ISOLDE

dipole, quadrupole, lattice, operation

1289

J. Bauche, A.V. Aloev
CERN, Geneva, Switzerland

This paper describes the design of the beam transfer line magnets of the HIE-ISOLDE facility. The technical solutions selected to face the challenges associated with the machine requirements are presented, and the final design parameters and field quality are reported.

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TUPME002

An Optimization of Positron Injector of ILC

positron, target, electron, booster

1334

M. Kuriki, Y. Seimiya
HU/AdSM, Higashi-Hiroshima, Japan
S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
T. Okugi, M. Satoh, J. Urakawa
KEK, Ibaraki, Japan

Funding: This work is supported by Photon and Quantum Basic Research Coordinated Development Program of MEXT.
ILC (International Linear Collider) is a future project of high energy physics. In the current baseline design, positron generation by gamma rays from undulator radiation is assumed. However, this approach is totally new and it is very difficult to demonstrate the system prior to the construction because it requires more than 100 GeV beam as the driver. A conventional positron generation (e-driven) has been proposed as a technical backup option. In this method, the technology is well established, but the issue is to obtain an enough amount of positron with a manageable energy deposition on target. We present a result of a systematic study of capture efficiency defined by DR (Damping Ring) acceptance where the beam emittance is reduced by radiation damping. We performed a start-to-end simulation of the positron source of ILC and found that an enough amount of the positron per bunch is obtained with a manageable energy deposition on the production target.

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TUPME012

The US Muon Accelerator Program

collider, factory, proton, target

1367

M.A. Palmer
Fermilab, Batavia, Illinois, USA

Funding: Work supported by US DOE under contract DE-AC02-07CH11359.
A directed R&D program is presently underway in the U.S. to evaluate the designs and technologies required to provide muon-based high energy physics (HEP) accelerator capabilities. Such capabilities have the potential to provide unique physics reach for the HEP community. An overview of the status of the designs for the neutrino factory and muon collider applications is provided. Recent progress in the technology R&D program is summarized.

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TUPME013

Thermo-mechanical Tests for the CLIC Two-beam Module Study

operation, alignment, vacuum, experiment

1370

A. Xydou, G. Riddone, A.L. Vamvakas
CERN, Geneva, Switzerland
E. Daskalaki
NTUA, Athens, Greece

The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite element analysis model and propagated back to engineering design. Finally, simulation of the most possible CLIC machine cycles is accomplished and preliminary results are analysed.

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TUPME040

Drive Beam Break-up Control and Practical Gradient Limitation in Collinear Dielectric Wakefield Accelerators

wakefield, acceleration, simulation, quadrupole

1443

C. Li, W. Gai, J.G. Power, A. Zholents
ANL, Argonne, Illinois, USA
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
C. Li, C.-X. Tang
TUB, Beijing, People's Republic of China

Dielectric wakefield accelerator (DWA) concept has gained significant attention for the need of the future large scale facilities. For a practical machine, one needs to overcome a major challenge for the DWA that is the efficient energy extraction and stable propagation at the same time for the drive beam. Typically, a slightly off axis beam become unstable in the dielectric channel due to transverse wakefield excitation, that could be controlled if a strong external alternating magnetic focusing channel applied at the same time. However, there is limitation on the practical magnetic field in the focusing channel (typically < 1 Tesla), thus imposing operating point for the DWA. In this article, we explore the operating point of the DWA for various structure frequencies and drive beam charge, particularly on the gradient and total acceleration distance, and provide guidance on the DWA design.

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TUPME041

The Advanced Superconducting Test Accelerator at Fermilab: Science Program

SRF, electron, emittance, laser

1447

P. Piot, E.R. Harms, S. Henderson, J.R. Leibfritz, S. Nagaitsev, V.D. Shiltsev, A. Valishev
Fermilab, Batavia, Illinois, USA

Funding: This work is supported by DOE contract DE-AC02-07CH11359 to the Fermi Research Alliance LLC
The Advanced Superconducting Test Accelerator (ASTA) currently in commissioning phase at Fermilab is foreseen to support a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop novel approaches to particle-beam generation, acceleration and manipulation. ASTA incorporates a superconducting radiofrequency (SCRF) linac coupled to a flexible high-brightness photoinjector. The facility also includes a small-circumference storage ring capable of storing electrons or protons. This report summarizes the facility capabilities, and provide an overview of the accelerator-science researches to be enabled.

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TUPME047

SINBAD - A Proposal for a Dedicated Accelerator Research Facility at DESY

plasma, experiment, electron, laser

1466

R.W. Aßmann, C. Behrens, R. Brinkmann, U. Dorda, K. Flöttmann, B. Foster, J. Grebenyuk, I. Hartl, M. Hüning, Y.C. Nie, J. Osterhoff, A. Rühl, H. Schlarb, B. Schmidt
DESY, Hamburg, Germany
M. Groß, B. Marchetti, F. Stephan
DESY Zeuthen, Zeuthen, Germany
F.J. Grüner, B. Hidding, A.R. Maier
Uni HH, Hamburg, Germany
F.X. Kärtner, B. Zeitler
CFEL, Hamburg, Germany
A.-S. Müller, M. Schuh
KIT, Karlsruhe, Germany

A new, dedicated accelerator research facility SINBAD (Short INnovative Bunches and Accelerators at DESY) is proposed. This facility is aimed at promoting two major goals: (1) Short electron bunches for ultra-fast science. (2) Construction of a plasma accelerator module with useable beam quality. Research and development on these topics is presently ongoing at various places at DESY, as add-on experiments at operational facilities. The two research goals are intimately connected: short bunches and precise femtosecond timing are requirements for developing a plasma accelerator module. The scientific case of a dedicated facility for accelerator research at DESY is discussed. Further options are mentioned, like the use of a 1 GeV beam from Linac2 for FEL studies and the setup of an attosecond radiation source with advanced technology. The presently planned conversion of the DORIS storage ring and its central halls into the SINBAD facility is described. The available space will allow setting up several independent experiments with a cost-effective use of the same infrastructure. National and international contributions and proposals can be envisaged.

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TUPME084

On the Frequency Choice for the eRHIC SRF Linac

SRF, cavity, HOM, electron

1547

S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, V. Ptitsyn, W. Xu
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko, V. Ptitsyn
Stony Brook University, Stony Brook, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the US DOE.
eRHIC is a future electron-hadron collider proposed at BNL. It will collide high-intensity hadron beams from one of the existing rings of RHIC with a 50-mA electron beam from a multi-pass 10-GeV superconducting RF (SRF) Energy Recovery Linac (ERL). A novel approach to the multi-pass ERL utilizing a non-scaling FFAG was recently proposed. It has many advantages over the previous designs including significant cost savings. The current design has 11 passes in two FFAG rings. To mitigate various beam dynamics effects, it was proposed to lower RF frequency of the SRF linac from 704 MHz used in the previous design. In this paper we consider different effects driving the frequency choice of the SRF ERL and present our arguments for choosing lower RF frequency.

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TUPRI001

ESSnuSB: A New Facility Concept for the Production of Very Intense Neutrino Beams in Europe

proton, target, detector, simulation

1550

E. Bouquerel, E. Baussan, M. Dracos, F.R. Osswald, P. Poussot, N. Vassilopoulos
IPHC, Strasbourg Cedex 2, France

A new project for the production of a very intense neutrino beam has arisen to enable the discovery of leptonic CP violation and neutrino mass hierarchy. This facility will use the proton linac of the European Spallation Source (ESS) in Lund to deliver the neutrino super beam. The ESS linac is expected to be fully operational at 5 MW power by 2022, producing 2 GeV and 2.86 ms long proton pulses at a rate of 14 Hz. An upgrade of the power to 10 MW and a frequency of 28 Hz, in which half is for the neutron beam, is necessary for the production of the neutrino beam. The primary proton beam-line completing the linac will consist of switchyards and accumulator rings. The secondary beam-line producing neutrinos will consist of a four-horn/target station, decay tunnel and beam dump. A megaton scale water Cherenkov detector will be located at a baseline of about 500 km in one of the existing mines in Sweden and it will measure the neutrino oscillations. The elements of the primary and secondary beam-lines and all the possible scenarios impacting the design of the ESSnuSB facility as well as the safety issues due to the high irradiation produced are presented and discussed in this paper.

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TUPRI002

The EUROnu Study for Future High Power Neutrino Oscillation Facilities

target, detector, factory, proton

1553

T.R. Edgecock
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The EUROnu project was a 4 year FP7 design study to investigate and compare three possible options for future, high power neutrino oscillation facilities in Europe. These three facilities are a Neutrino Factory, a neutrino superbeam from CERN to the Frejus Laboratory and a so-called Beta Beam. The study was completed at the end of 2012 and has produced conceptual designs for the facilities and preliminary cost estimates. The designs were used to determine the physics performance. These have been used to compare the facilities. This paper will describe the designs, physics performance and costs and summarise the recommendations of the study.

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TUPRI044

Investigation of Microbunching-instability in BERLinPro

electron, simulation, space-charge, emittance

1662

S.D. Rädel, A. Jankowiak, A. Meseck
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
BERLinPro is using the new energy recovery linac technology. As, maintaining the low emittance and energy spread is of major importance in an ERL, the deep understanding and control of effects which can degrade the emittance and energy spread such as space charge effects are of interest. The microbunching caused by the longitudinal space charge forces can lead to an increase in emittance and energy spread in the arcs of the loop. In this contribution, the impacts of the microbunching instability on the beam quality and its implication for BERLinPro are discussed.

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TUPRI080

Emittance Optimisation in the Drive Beam Recombination Complex at CTF3

emittance, feedback, controls, simulation

1754

D. Gamba, F. Tecker
CERN, Geneva, Switzerland
D. Gamba
JAI, Oxford, United Kingdom

According to the Conceptual Design Report, the power to accelerate the main colliding beams of CLIC is taken from parallel high intensity (100 A), low energy (2.37 GeV) beams. These beams are generated by long trains, accelerated by conventional klystrons and then time-compressed in the so called Drive-Beam Recombination Complex (DBRC). A scaled version of the DBRC has been built at the CLIC Test Facility (CTF3) at CERN in order to prove its principle and study any arising feasibility issues. One of the main constraints is the emittance control during the recombination process. This work presents an overview of the studies ongoing at CTF3, keeping in view possible improvements of the nominal CLIC design. In particular, a generic feedback algorithm to solve (quasi-)linear systems has been implemented and used in order to optimise the process by tuning the energy of the beam and steer the orbits in the different lines, as well matching the design dispersion. Current results and possible room for further optimisation will be shown.

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TUPRI090

Linac Alignment for SuperKEKB Injector

alignment, laser, emittance, positron

1781

T. Higo, K. Kakihara, T. Kamitani, M. Satoh, R. Sugahara, T. Suwada, M. Tanaka
KEK, Ibaraki, Japan

The misalignment of the linac beamline components amounted to be a millimeter level during the operation of KEKB, though the requirement of 0.1mm in mind. The limited effort toward improving such big misalignments has long been pursued but could not finish especially after the earthquake in March 2011. This linac is now under upgrade to the SuperKEKB, where the required alignment is 0.1mm in σ for the short distance in 100m span, while 0.3mm through the whole linac for the emittance preservation. The straight line as a reference for the alignment was defined by laser beam over 500m. The actual hardwares are set with respect to this reference line by using a laser tracker. The alignment present status is reported in this paper. On the other hand, we noticed, through the alignment measurements over months, that the tunnel floor moved in the range of 0.1mm or maybe more. The evaluation of this movement is on-going to discuss about how to achieve the required emittance and how to keep the situation. Various measurements to evaluate the movement are presented also in the paper.

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TUPRI091

Refinement of ARC Alignment between Two Straight Sections for Injector Linac of SuperKEKB

alignment, laser, emittance, quadrupole

1784

M. Tanaka, T. Higo, K. Kakihara, T. Kamitani
KEK, Ibaraki, Japan
K. Kimura, K. Suzuki, N. Toyotomi, S. Ushimoto
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

The beam line of the KEKB injector linac is under realignment as the restoration after the big Earthquake in 2011, but with the refinement for the SuperKEKB in mind. The linac consists of two straight sections connected by a 180 degree ARC. Precise alignment of the ARC magnets is one of the key issues for the emittance preservation of the electron beam. The ARC beam line was defined by measuring these two straight lines. Then, the misalignment of the ARC magnets were reduced from 3 mm maximum down to 0.1mm in the errors perpendicular to the beam direction. This paper describes how we defined the ARC beam line and performed the alignment. The connection method of the laser tracker data needed for the definition of the ARC was also studied and described.

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TUPRI092

Improvement of the Position Monitor using White Light Interferometer for Measuring Precise Movement of Compact ERL Superconducting Cavities in Cryomodule

target, cryomodule, cavity, operation

1787

H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
T. Aoto, K. Hayashi, K. Kanzaki
Tokyo Seimitsu Co. Ltd, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

Alignment of superconducting cavities is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to liquid He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL (cERL) and successfully measured the displacement during 2K cooling with the resolution of 10um. However, some drift come from outer temperature and humidity were observed. In this paper, we describe the upgraded version of this monitor to suppress these drift for cERL beam operation.

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TUPRI095

Design and Study on a 5 Degree-of-freedom Adjustment Platform for CLIC Drive Beam Quadrupoles

quadrupole, alignment, linear-collider, collider

1796

M. Sosin, M. Anastasopoulos, M. Duquenne, J. Kemppinen, H. Mainaud Durand, V. Rude, J. Sandomierski
CERN, Geneva, Switzerland

Since several years CERN is studying the feasibility of building a high energy e⁺ e⁻ linear collider: the CLIC (Compact LInear Collider). The pre-alignment precision and accuracy requirement for the transverse positions of the linac components is typically 14 micrometers over a sliding window of 200m. One of the challenges is precise adjustment of Drive Beam quadrupole’s magnetic axis. It has to be done with micrometric resolution along 5 DOF in a common support’s coordinate system. This paper describes the design and the study of a solution based on flexural components in a type of “Stewart Platform” configuration. The engineering approach, the lessons learned (“know how”), the issues of adjustment solution and the mechanical components behaviors are presented.

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TUPRI098

The New PLC based Radiation Safety Interlock System at S-DALINAC

electron, radiation, operation, status

1802

M. Arnold, J. Birkhan, M. Brunken, J. Conrad, M. Hess, F. Hug, N. Pietralla, S.T. Sievers, P. von Neumann-Cosel
TU Darmstadt, Darmstadt, Germany

Funding: Supported by a HGS-HIRe travel grant
The Superconducting Darmstadt Linear Electron Accelerator S-DALINAC has been running since 1991. It consists of an injector linac, a main linac with two recirculations and is mainly used for in-house nuclear physics experiments as well as accelerator physics and technology. Radiation safety regulations demand an interlock system during operation of the accelerator. Amongst other major projects increasing the versatility and operation stability of the S-DALINAC, the existing, hardware based, interlock system is going to be replaced in the next shutdown period. The new interlock system is based on a PLC (Programmable Logic Controller) and will provide two subsystems, a personnel interlock system as well as a machine safety interlock system. Whereas the first subsystem is to protect staff and visitors from being harmed by ionizing radiation, the latter subsystem prohibits the S-DALINAC beam transport and vacuum elements from being damaged due to malfunctioning of any components during accelerator operation. This contribution will give an overview on this new system and will show the latest status.

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TUPRI109

Construction and Commissioning of Event Timing System at SuperKEKB

timing, injection, positron, software

1829

H. Kaji, K. Furukawa, M. Iwasaki, E. Kikutani, T. Kobayashi, F. Miyahara, T.T. Nakamura, M. Satoh, M. Suetake, M. Tobiyama
KEK, Ibaraki, Japan
T. Kudo, S. Kusano
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
T. Okazaki
EJIT, Hitachi, Ibaraki, Japan

The Event Timing System of Injector Linac at KEK is upgraded to satisfy the new requirements for the SuperKEKB project. After finishing the design and feasibility studies*, we have constructed the new system at Main Trigger Station of Linac. The new functions are developed in this system to perform the injection control of positrons with the newly constructed damping ring. Besides, we integrate the capability to adjust the trigger timing just 20 ms before injection so that the injection RF-bucket of the ring can be decided at the last minute. Now, both the new system and the current working system are operational at Main Trigger Station. This is important for the smooth taking over of Event Timing System. Even during the construction period, Linac must be operated to provide beams into the two light source rings. In this situation, we can carry out enough tests with the actual condition. These tests do not disturb the regular operation and brush up the Event Timing System to enable the quick startup of the SuperKEKB operation. We report about the detailed configuration of the new system and its commissioning performed in the 2014 spring run period.
* H. Kaji et al., "Upgrade of Event Timing System at SuperKEKB",
proceedings of ICALEPCS13, San Francisco, USA, October 6-11, 2013.

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WEYA01

Challenges of Radioactive Beam Facilities – Comparing Solutions at SPIRAL2 and FAIR

ion, target, ISOL, heavy-ion

1852

R. Ferdinand
GANIL, Caen, France

The SPIRAL2 facility at GANIL will use a high-power p, d and heavy-ion driver to produce RIB though both ISOL and in-flight techniques. The SPIRAL2-injector beam is expected before the end of 2014. The construction of the FAIR facility has started at GSI and the outline of the accelerator complex is well defined. A clear strategy and construction schedule is defined in the framework of the international FAIR collaboration. This talk will give an overview of the accelerators at both facilities and compare the characteristics and benefits of these two approaches to meet their user needs.

Slides WEYA01 [9.134 MB]

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WEOBA02

Superconducting Linac for Rare Isotope Science Project

cavity, cryomodule, ion, proton

1861

H.J. Kim, H.J. Cha, M.O. Hyun, H. Jang, H.C. Jung, Y. Kim, M. Lee, G.-T. Park
IBS, Daejeon, Republic of Korea

Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.5 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the status of RISP linac design and the development of superconducting cavity and cryomodule.

Slides WEOBA02 [9.226 MB]

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WEZA02

A Staged Muon Accelerator Facility for Neutrino and Collider Physics

collider, factory, proton, target

1872

J.-P. Delahaye
SLAC, Menlo Park, California, USA
C.M. Ankenbrandt, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, S.D. Holmes, R.J. Lipton, D.V. Neuffer, M.A. Palmer
Fermilab, Batavia, Illinois, USA
S.A. Bogacz
JLab, Newport News, Virginia, USA
P. Huber
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
D.M. Kaplan, P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA
H.G. Kirk, R.B. Palmer
BNL, Upton, Long Island, New York, USA
R.D. Ryne
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Dept. of Energy under contracts DE-AC02-07CH11359 and DE-AC02-76SF00515
Muon-based facilities offer unique potential to provide capabilities at both the Intensity Frontier with Neutrino Factories and the Energy Frontier with Muon Colliders. They rely on a novel technology with challenging parameters, for which the feasibility is currently being evaluated by the Muon Accelerator Program (MAP). A realistic scenario for a complementary series of staged facilities with increasing complexity and significant physics potential at each stage has been developed. It takes advantage of and leverages the capabilities already planned for Fermilab, especially the strategy for long-term improvement of the accelerator complex being initiated with the Proton Improvement Plan (PIP-II) and the Long Baseline Neutrino Facility (LBNF). Each stage is designed to provide an R&D platform to validate the technologies required for subsequent stages. The rationale and sequence of the staging process and the critical issues to be addressed at each stage, are presented.

Slides WEZA02 [27.263 MB]

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WEOAB03

Linear Electron Acceleration in THz Waveguides

electron, acceleration, laser, accelerating-gradient

1896

E.A. Nanni, W.S. Graves, K.-H. Hong, W.R. Huang, F.X. Kärtner, KR. Ravi, L.J. Wong
MIT, Cambridge, Massachusetts, USA
A. Fallahi, F.X. Kärtner
CFEL, Hamburg, Germany
R.J.D. Miller
DESY, Hamburg, Germany
G. Moriena
University of Toronto, Toronto, Ontario, Canada

Funding: Supported by DARPA N66001-11-1-4192, CFEL DESY, DOE DEFG02-10ER46745, DOE DE-FG02-08ER41532, ERC Synergy Grant 609920 and NSF DMR-1042342.
We report the first experimental demonstration of linear electron acceleration using an optically generated single cycle THz pulse centered at 0.45 THz. 7 keV of acceleration is achieved using 10 microJ THz pulses in a 3 mm interaction length. The THz pulse is produced via optical rectification of a 1.2 mJ, 1 micron laser pulse with a 1 kHz repetition rate. The THz pulse is coupled into a dielectric-loaded circular waveguide with 10 MeV/m on-axis accelerating gradient. A 25 fC input electron bunch is produced with a 60 keV DC photo-emitting cathode. The achievable accelerating gradient in the THz structures being investigated will scale rapidly by increasing the IR pulse energy (100 mJ - 1 J) and correspondingly the THz pulse energy. Additionally, with recent advances in the generation of THz pulses via optical rectification, in particular improvements to efficiency and generation of multi-cycle pulses, GeV/m accelerating gradients could be achieved. An ultra-compact high-gradient THz accelerator would be of interest for a wide variety of applications.

Slides WEOAB03 [7.185 MB]

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WEYB01

Large Dynamic Range Beam Diagnostics for High Average Current Electron LINACs

diagnostics, FEL, brightness, optics

1900

P.E. Evtushenko
JLab, Newport News, Virginia, USA

A number of applications is envisioned now for CW electron LINACs with high average current. A few examples are: driver-accelerators for the next generation of high average brightness SR sources, energy recovery LINACs to be used for frontier research in particle physics - search for dark matter candidate particles, industrial and defense applications. An average beam power of MWs is considered for such applications. Such machines will be required to operate simultaneously with high beam power and peak brightness comparable to the brightest electron beams generated in pulsed LINACs. Combining the high current advantages of storage rings and high peak brightness of LINACs will require such understanding and control of the beam dynamics that 10^-6 fraction of the beam current is taken in to account and controlled during the beam tuning. To make this possible a number of large dynamic range (LDR) (~10⁺⁶) beam diagnostics is under development and test at JLab FEL. Transverse and longitudinal LDR beam profile measurements can be used for LDR measurements of the phase space distribution and its evolution through the accelerator.

Slides WEYB01 [4.581 MB]

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WEIB02

RF Sub-Systems for Cargo and Vehicle Inspection

detector, photon, vacuum, scattering

1917

D.J. Mistry, T.A. Cross, C.R. Weatherup
e2v, Chelmsford, Essex, United Kingdom

X-ray screening for security is a well-established inspection technique. Whilst in terms of fielded systems the vast majority consist of low energy X-ray sources, typically used for hand baggage or mail screening. There is a smaller but high value niche market servicing the requirements for border security, and cargo and vehicle inspection (CVI). This latter application requires higher X-ray energies of up to 10 MeV using an electron linear accelerator (linac) source to penetrate fully loaded shipping containers. Increasingly, methods are required to improve throughput and provide a higher level of material discrimination during inspection. This paper will briefly review the elements required to make an effective X-ray source, whilst outlining the RF technology required to drive a linac-based X-ray security system. Following this, potential new developments in radiofrequency (RF) sub-systems will be discussed in the context of user benefits.
Abstract redrafted 10.6.14
Original abstract: redrafted 6.12.13. 'The purpose of this presentation is to provide an understanding of global industry security systems and the role of accelerators…'

Slides WEIB02 [5.892 MB]

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WEPRO005

Development of Superconducting Spoke Cavity for Laser Compton Scattered Photon Sources

cavity, HOM, brightness, photon

1946

M. Sawamura, R. Hajima, R. Nagai
JAEA, Ibaraki-ken, Japan
H. Fujisawa, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
T. Kubo
KEK, Ibaraki, Japan

Funding: This work is supported by Photon and Quantum Basic Research Coordinated Development Program.
We have launched a 5-year research program to develop superconducting spoke cavity for laser Compton scattered (LCS) photon sources. For realizing a wide use of LCS X-ray and gamma-ray sources in academic and industrial applications, we adopt 325-MHz superconducting spoke cavity to electron beam drivers for the LCS sources. The spoke cavity, originally invented for ion and proton acceleration, can be used for electron accelerators, in which we can make best use of features of spoke cavity: relative compactness in comparison with a TM cavity of the same frequency, robustness with respect to manufacturing inaccuracy due to its strong cell-to-cell coupling, couplers on outer conductor for the better packing in a linac, and so on. In this paper, we present our research plan and results of cavity shape optimization.

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WEPRO007

Nanometer Scale Coherent Current Modulation via a Nanotip Cathode Array and Emittance Exchange

electron, emittance, cavity, gun

1952

E.A. Nanni, W.S. Graves
MIT, Cambridge, Massachusetts, USA
P. Piot
Fermilab, Batavia, Illinois, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: NSF DMR-1042342, DARPA N66001-11-1-4192
We present PIC simulations of electron bunches with nm scale longitudinal modulation produced using a compact 2-20 MeV LINAC. The modulation is initially imparted in the transverse dimension of the electron bunch with a nano-patterned photo-emitter in a X-band RF gun with 2 MeV exit energy. The electron bunch passes through a 1 m standing wave X-band LINAC which can raise the beam energy up to 20 MeV. The transverse modulation is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. The modulation pitch can be tuned by adjusting the spacing of the nano-patterned photo-emitter or magnification of the transverse pitch with electron optics. The electron beam parameters are optimized to produce coherent XFEL radiation upon interacting with a “laser undulator”.

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WEPRO008

A Beam-driven Microwave Undulator for FEL

undulator, wakefield, electron, FEL

1956

A. Kanareykin, C.-J. Jing, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Baturin
LETI, Saint-Petersburg, Russia
A. Zholents
ANL, Argonne, Ilinois, USA

Funding: DOE SBIR
Microwave waveguides can in principle be used for undulators with periods less than 1 cm. Intensive work has been done on the recently proposed design that operates at the HE11 hybrid mode of a corrugated waveguide; successful experimental results have been reported recently [S.Tantawi Talk at POSIPOL 2012]. In this presentation we propose a beam driven design for an undulator based on an electron bunch train powering a microwave or mm waveguide. The drive bunch train propagates towards the undulating beam inside a dielectric loaded structure or corrugated waveguide generating high power RF. The “smart” waveguide design and a proper bunch spacing of the electron drive beam train provide single mode generation of the high magnitude undulating field that gives an undulator parameter in the range of K~1 for a high frequency device.*
*A. Zholents, HBEB Workshop, Puerto-Rico, 2013.

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WEPRO015

RF Injector Beam Dynamics Optimization for LCLS-II

emittance, simulation, brightness, cathode

1974

C. F. Papadopoulos, D. Filippetto, F. Sannibale
LBNL, Berkeley, California, USA
P. Emma, T.O. Raubenheimer, J.F. Schmerge, L. Wang, F. Zhou
SLAC, Menlo Park, California, USA

Funding: This work was supported in part by the Work supported, in part, by the LCLS-II Project and by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
LCLS-II is a proposal for a high repetition rate (>1 MHz) FEL, based on a CW, superconducting linac. The LCLS-II injector is being optimized by a collaboration from Cornell University, Fermilab, LBNL, and SLAC. There are a number of different possible technical choices for the injector including an rf gun or a high voltage DC gun. In this paper we present the status of the simulations for the injector optimization for an rf gun choice for LCLS-II. A multiobjective genetic optimizer is implemented for this reason, and optimized solutions for different bunch charges, corresponding to different operating modes, are presented. These operating points are also the initial part of the start-to-end simulations for LCLS-II. Finally, we discuss the trade-offs between compression and brightness conservation in the low energy (<100 MeV) part of the accelerator, as well as the status of sensitivity studies.

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WEPRO018

Theoretical Maximum Current of the NSLS-II Linac

simulation, beam-loading, cavity, gun

1980

R.P. Fliller, F. Gao, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An analysis of the maximum available NSLS-II linac current was performed as part of the preparation for NSLS-II Booster commissioning. The analysis was necessary in order to establish the maximum beam current available from the linac and the maximum current that would be available to the booster accelerator. In this paper we discuss the assumptions that were used in determining the maximum linac current, the model of the linac and comparison to operational conditions.

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WEPRO019

Comparison of the NSLS-II Linac Model to Measurements

cathode, emittance, simulation, gun

1983

R.P. Fliller
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
The NSLS-II linac and associated transport lines were successfully installed and commissioned in the spring of 2012. Various beam measurements were performed to ensure that the linac met specifications and would be a suitable injector for the NSLS-II booster. In this paper we discuss the outcomes of these measurements and compare them to the model of the NSLS-II linac.

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WEPRO022

Modal Analysis of Helical Undulator Radiation In Cylindrical Waveguide

radiation, undulator, vacuum, FEL

1989

T.L. Vardanyan, M. Ivanyan, V. Sahakyan, A.V. Tsakanian, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia

The coherent radiation of the relativistic electron beam with helical orbit in circular waveguide is studied. The radiation field configuration is obtained using modal expansion technique. For short electron bunches the coherent part of radiation is evaluated. The coherent radiation effects on the bunch performance are analyzed.

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WEPRO067

Development of NICA Injection Complex

ion, rfq, ion-source, DTL

2103

A.V. Butenko, E.E. Donets, A.D. Kovalenko, K.A. Levterov, A.O. Sidorin, G.V. Trubnikov
JINR/VBLHEP, Moscow, Russia
A. Belov
RAS/INR, Moscow, Russia
E.D. Donets, V.V. Fimushkin, A. Govorov, V. Kobets, V. Monchinsky
JINR, Dubna, Moscow Region, Russia
H. Höltermann, H. Podlech, U. Ratzinger, A. Schempp
BEVATECH, Frankfurt, Germany
T. Kulevoy, D.A. Liakin
ITEP, Moscow, Russia
S.M. Polozov
MEPhI, Moscow, Russia

The new accelerator complex Nuclotron-based Ion Collider fAcility (NICA) is assumed to operate using two linear accelerators: the Alvarez-type linac LU-20 as injector for light ions, polarized protons and deuterons and a new linac HILac for heavy ions. The new Booster and existing Nuclotron superconducting rings are the main parts of the injection complex of the NICA collider. The status of ion sources, both linacs and rings is presented.

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WEPRO072

The Design of the Fast Raster System for the European Spallation Source

target, timing, power-supply, controls

2118

H.D. Thomsen, S.P. Møller
ISA, Aarhus, Denmark

The ESS will nominally operate with an average (peak) proton current of 2.5 mA (62.5 mA) at 2.0 GeV. To reduce the beam peak current density at the spallation target, the ESS HEBT will apply a fast transverse raster system consisting of 8 dithering magnet dipoles. The raster system sweeps the linac beamlet on the target surface and gives a rectangular intensity outline within a macropulse of 2.86 ms. The magnets are driven by triangular current waveforms of up to 40 kHz. The preliminary magnet design and power supply topology will be discussed.

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WEPRO073

The ESS High Energy Beam Transport after the 2013 Design Update

optics, target, dipole, quadrupole

2121

H.D. Thomsen, S.P. Møller
ISA, Aarhus, Denmark

Following an optimization of the European Spallation Source (ESS) linac, a number of changes have been introduced in the High Energy Beam Transport (HEBT). In particular, about 120 m of beam transport has been allocated to enable an extension of the superconducting linac, thus providing some contingency against poor linac performance and potentially allowing a future beam power upgrade. The changes in layout and beam optics in all HEBT lines will be discussed.

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WEPRO075

The Conceptual Design of the China White Neutron Source

DTL, neutron, rfq, resonance

2127

J.H. Li, X.C. Ruan, X. Wang
CIAE, Beijing, People's Republic of China
J.H. Billen, K.R. Crandall
TechSource, Los Alamos, New Mexico, USA
J. Stovall
ESS, Lund, Sweden
J.Y. Tang
IHEP, Beijing, People's Republic of China
L.M. Young
AES, Medford, New York, USA

Funding: Work supported by NSFC of (91126003)
In order to feed the nuclear data needs for design of the Chinese Accelerator Driven sub-critical System (CADS) and new generation nuclear energy systems, we plan to construct the China White Neutron Source (CWNS). The CWNS will be composed of a Proton Linac, an Accumulator Ring, a Target and Experimental Facilities. The linac is designed to deliver a proton beam having an average current of 1 mA at energy up to 300 MeV. The revolution frequency of the accumulator ring will be ~1.4 MHz. Two spallation targets are planned, with one for short pulsed modes and the other for micro-pulsed mode.

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WEPRO076

Constructing the ESS Linear Accelerator: Pragmatic Approaches to Design and System Integration at the European Spallation Source

software, interface, hardware, proton

2131

G. Lanfranco, M.J. Conlon, N. Gazis, E. Tanke, E. Vaena
ESS, Lund, Sweden

The European Spallation Source (ESS) is a neutron science facility comprising a linear H⁺ accelerator, a tungsten target station, 22 neutron instruments, a suite of laboratories and a supercomputing data processing centre. The Accelerator project represents about a third of the total ESS construction budget and several European countries participate as in-kind contributing partners to it. It is crucial to guarantee requirements consistency, clarity of interface definition and proper space allocation. Potential functional and design inconsistencies must be promptly detected and actively resolved, bridging the project from the conceptual design towards a smooth, cost and time effective installation. Moreover, while the correct synergies are established and maintained, the organisational burden has to be minimized, aspect particularly relevant given the intrinsic prototypic nature of projects of this type. This paper describes the system architecture and the tools deployed to integrate the design of the ESS Linear Accelerator and to prepare for its installation.

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WEPRO079

Accelerator Systems Modifications for a Second Target Station at the Oak Ridge Spallation Neutron Source

septum, target, kicker, quadrupole

2140

M.A. Plum, J. Galambos, S.-H. Kim
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
A second target station is planned for the Oak Ridge Spallation Neutron Source. The ion source will be upgraded to increase the peak current from 38 to 49 mA, additional superconducting RF cavities will be added to the linac to increase the H− beam energy from 933 to 1300 MeV, and the accumulator ring will receive modifications to the injection and extraction systems to accommodate the higher beam energy. After pulse compression in the storage ring one sixth of the beam pulses (10 out of 60 Hz) will be diverted to the second target by kicker and septum magnets added to the existing Ring to Target Beam Transport (RTBT) line. No further modifications will be made to the RTBT so that when the kicker and septum magnets are turned off the original target 1 beam transport lattice will be unaffected. In this paper we will discuss these and other planned modifications and upgrades to the accelerator facility, and also the status of this project.

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WEPRO086

Experimental Activity in the ENEA-Frascati Irradiation Facility with 3-7 MeV Protons

proton, experiment, detector, DTL

2156

M. Vadrucci, A. Ampollini, F. Bonfigli, M.C. Carpanese, F. Marracino, R.M. Montereali, P. Nenzi, L. Picardi, M. Piccinini, C. Ronsivalle, V. Surrenti, M.A. Vincenti
ENEA C.R. Frascati, Frascati (Roma), Italy
F. Ambrosini
URLS, Rome, Italy
M. Balduzzi, C. Marino, C. Snels
ENEA Casaccia, Roma, Italy
M. Balucani, A. Klyshko
University of Rome "La Sapienza", Rome, Italy
C. De Angelis, G. Esposito, M.A. Tabocchini
ISS, Rome, Italy

A variable energy (3-7 MeV) and pulsed current (0.1 – 100 μA) proton beam has been made available for different applications (radiobiology experiments, detectors development, material studies) in an irradiation facility at ENEA-Frascati based on the 7 MeV injector of the protontherapy linac under realization in the framework of the TOP-IMPLART Project. It is a 425 MHz linear accelerator consisting in a 3 MeV RFQ followed by a DTL up to 7 MeV (PL-7 ACCSYS-HITACHI model) followed by an horizontal and a vertical beam transport line. The latter one is particularly suitable for radiobiology in vitro studies allowing to irradiate besides cell monolayes also cell growing in suspension culture. The paper describes the facility and the recent results of the experimental activity.

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WEPRO089

Latest Developments of a C-band 2MeV Accelerator

experiment, operation, status, detector

2165

W. Bai, M. Li, L.J. Shan, X.M. Shen, Z. Xu
CAEP/IAE, Mianyang, Sichuan, People's Republic of China

A C-band 2MeV accelerator is developped at CAEP in China. This research is aimmed at developing an compact accelerator used as X ray source for industrial useage. At present, the C-band accelerator has been developed successfully. we have carried out a lot of research work based on the accelerator, including test of X ray energy, focus and dose rate etc. This paper shows the latest experimental results and application research status on the C-band accelerator.

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WEPRO090

Status of KAERI 6 MeV 9.3 GHz X-Band Electron Linac for Cancer Treatment System

electron, cavity, gun, radiation

2168

B.N. Lee, B.C. Lee, S.H. Lee, S. Lee, H.D. Park, K.B. Song
KAERI, Dae-jeon, Republic of Korea
P. Buaphad, Y. Kim
ISU, Pocatello, Idaho, USA
S.S. Cha
UST, Daejeon City, Republic of Korea

Funding: This work was supported by a grant from the (NRF funded by the MSIFP, Korea (No.2013M2A2A4023350) and the Industrial Strategic technology development program, 10043897, funded By the MOTIE, Korea.
The X-band RF linear accelerators (LINAC’s) are popular for medical application due to its compactness. To increase the precision of treatment accuracy under circumstance in which the LINAC is mounted on an apparatus such as gantry frame or robot-arm; this is an advantage as the weight and size are more reduced. It is a 9.3 GHz magnetron with the most readily available RF generator in the X-band frequencies from 8 GHz to 12 GHz and the magnetron is mainly used for the source of the RF power in a compact LINAC. The average power of the magnetron at 9.3~GHz is generally a few MW and this amount could provide a sufficient radiation dose-rate for tumour therapy. KAERI has been developing a new compact 9.3 GHz X-band electron LINAC for a cancer treatment system. The maximum energy of the electron beam is 6 MeV and the average beam power at the tungsten target is about 1 kW. In this paper, we describe the status of development of the 6 MeV X-band LINAC at KAERI.

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WEPRO097

The Base Parameters of the Compact 27 GHz Electron Linac for Medical Application

electron, simulation, injection, coupling

2189

S.M. Polozov, T.V. Bondarenko, Yu.D. Kliuchevskaia, V.I. Rashchikov
MEPhI, Moscow, Russia

A compact and light-weight electron linac is attractive for a number of medical applications including intra-operational and cyber-knife systems. The design of such an accelerator can nowadays be based on using of a powerful high-voltage high-frequency gyrotron which can provide now in pulsed regime a peak power up to 15 MW at the frequency about of 30 GHz. Taking into account this possibility, the paper presents the results of design and numerical simulations for the electron beam dynamics in a linac with the operating frequency of 27 GHz. Designed linac consists of two parts: gentle buncher and main accelerating section. The beam bunching is complicated at 1 cm wavelength because high energy about 2 MeV is necessary for beam injection into the main stage with v/c=1. Beam dynamics simulations are held using BEAMDULAC-BL code*. The electrodynamics of accelerating structure based on biperiodic structure is presented. The electron gun simulation is also discussed. The RF feeding is planned to be realized using a gyrotron to be designed in IAP RAS. The gyrotron is capable to produce 2 MW peak RF power in pulses with pulse duration 400 μs and repetition rate 10 Hz.
T.V. Bondarenko, E.S. Masunov, S.M. Polozov. BEAMDULAC-BL code for 3D simulation of electron beam dynamics taking into account beam loading and coulomb field. PAST, 2014 (in press).

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WEPRO104

Backscattering X-ray System by using 950 keV X-band Linac X-ray Source

photon, target, detector, simulation

2209

C. Liu
The University of Tokyo, Tokyo, Japan
T. Fujiwara, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
J. Kusano
Accuthera Inc., Kawasaki, Kanagawa, Japan

Recently several tunnel collapses have happened in the world. To prevent this kind of accidents, the non-destructive inspection for tunnel is seriously needed. Backscattering X-ray system which makes one-side operation possible is a very important way to solve this problem. But the backscattering X-ray systems using X-ray tubes could only get the superficial information of the concrete target*. Now we are using our 950 keV X-ray source to construct the backscattering X-ray system to detect the deeper part of the concrete target.
*D. Shedlok, T. Edwards, C.Toh, “X-ray Backscatter Imaging for Aerospace Applications”, Review of Progress in Quantitative Nondestructive Evaluation, Volume 30 AIP Conf. Proc. 1335, 509-516, (2011).

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WEPRO115

The Star Project

laser, electron, photon, scattering

2238

A. Bacci, D.T. Palmer, L. Serafini, V. Torri
Istituto Nazionale di Fisica Nucleare, Milano, Italy
R.G. Agostino, G. Borgese, M. Ghedini, F. Martire, C. Pace
UNICAL, Arcavacata di Rende, Italy
D. Alesini, M.P. Anania, M. Bellaveglia, F.G. Bisesto, G. Di Pirro, A. Esposito, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, B. Spataro, C. Vaccarezza, F. Villa
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
G. D'Auria, A. Fabris, M. Marazzi
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
T. Levato
Czech Republic Academy of Sciences, Institute of Physics, Prague, Czech Republic
V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
E. Puppin
Politecnico/Milano, Milano, Italy
P. Tomassini
Università degli Studi di Milano, Milano, Italy

We present on overview of the STAR project (Southern european Thomson source for Applied Research), in progress at the Univ. of Calabria (Italy) aimed at the construction of an advanced Thomson source of monochromatic tunable, ps-long, polarized X-ray beams, ranging from 20 to 140 keV. The project is pursued in collaboration among: Univ. della Calabria, CNISM, INFN and Sincrotrone Trieste. The X-rays will be devoted to experiments of matter science, cultural heritage, advanced radiological imaging with micro-tomography capabilities. One S-band RF Gun at 100 Hz will produce electron bunches boosted up to 60 MeV by a 3m long S-band TW cavity. A dogleg will bring the beam on a parallel line, shielding the X-ray line from the background radiation due to Linac dark current. The peculiarity of the machine is the ability to produce high quality electron beams, with low emittance and high stability, allowing to reach spot sizes around 15-20 microns, with a pointing jitter of the order of a few microns. The collision laser will be based on a Yb:Yag 100 Hz J-class high quality laser system, synchronized to an external photo-cathode laser and to the RF system to better than 1 ps time jitter.

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WEPRO117

The Accumulator of the ESSnuSB for Neutrino Production

injection, proton, target, lattice

2245

E.H.M. Wildner, J. Jonnerby, J.-P. Koutchouk, M. Martini, H.O. Schönauer
CERN, Geneva, Switzerland
E. Bouquerel, M. Dracos, N. Vassilopoulos
IPHC, Strasbourg Cedex 2, France
T.J.C. Ekelöf, R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
M. Eshraqi, M. Lindroos, D.P. McGinnis
ESS, Lund, Sweden

The European Spallation Source (ESS) is a research centre based on the world’s most powerful neutron source currently under construction in Lund, Sweden, using 2.0 GeV, 2.86 ms long proton pulses at 14 Hz for the spallation facility (5MW on target). The possibility to pulse the linac at 28 Hz to deliver, in parallel with the spallation neutron production, a very intense, cost effective, high performance neutrino beam. The high current in the horns of the target system for the neutrino production requires proton pulses far shorter than the linac pulse. Therefore an accumulator ring is required after the linac to produce the shorter pulses. Charge exchange injection of an H⁻ beam from the linac would be used. The Linac would deliver 1.1 10¹⁵ protons per pulse. Due to space charge limits, several rings or one ring re-filled several times during the neutrino cycle are necessary. A cost effective design of an accumulator that can handle this large number of ions will be shown, taking into account the structure of the linac pulse and the requirements of the target system. Beam dynamics issues, the injection system, the extraction and the distribution on the targets are addressed.

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WEPRO118

THz Radiation Generation in Multimode Wakefield Structures

radiation, wakefield, experiment, electron

2248

S.P. Antipov, S.V. Baryshev, C.-J. Jing, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
M.G. Fedurin
BNL, Upton, Long Island, New York, USA
W. Gai, A. Zholents
ANL, Argonne, Illinois, USA
D. Wang
TUB, Beijing, People's Republic of China

Funding: DOE SBIR
A number of methods for producing sub-picosecond electron bunches have been demonstrated in recent years. A train of these bunches is capable of generating THz radiation via multiple mechanisms like transition, Cherenkov and undulator radiation. We propose to use a bunch train like this to selectively excite a high order mode in a dielectric wakefield structure. This allows us to use wakefield structures that are geometrically larger and easier to fabricate for beam-based THz generation. In this paper we present a THz source design based on this concept and experimental progress to date.

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WEPME003

Two Years Experience with the Upgraded ELBE RF System Driven by 20kW Solid State Amplifier Blocks (SSPA)

operation, klystron, cavity, SRF

2257

H. Büttig, A. Arnold, A. Büchner, M. Justus, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig, G.S. Staats, J. Teichert
HZDR, Dresden, Germany

Since January 2012 the Superconducting CW Linac ELBE is equipped and in permanent operation with four 20 kW Solid State Amplifier Blocks. The poster gives an overview on the design of the new RF system and the experience gained within the first two years of operation.

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WEPME010

Implementation of Single Klystron Working Mode at the ALBA Linac

klystron, booster, operation, synchrotron

2276

R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a third generation synchrotron light source whose injector consists of a 100 MeV Linac and a Booster that accelerates the beam up to the full energy, 3 GeV. Two pulsed klystrons are used to feed the Linac cavities. Klystron 1 feeds the bunching section and also the first accelerating structure. Klystron 2 feeds exclusively the second accelerating structure. Recently, a S-band switching system installed in the waveguide system allows us to use also Klystron 2 to power the low-energy section and operate the Linac at lower energy, around 65 MeV. So that injection into the Booster is still possible while, in the meantime, Klystron 1 can be connected to a dummy load for reparation. Therefore, the time response after a klystron failure is improved. Details of the waveguide upgrade and the results of the ALBA Linac operated with only one klystron are presented.

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WEPME011

2 kW Balanced Amplifier Module for a 30 kW Solid-State Pulsed RF Power Amplifier at 352 MHz

controls, operation, proton, vacuum

2279

A. Kaftoosian, P.J. González
ESS Bilbao, LEIOA, Spain

Design and development of a 30 kW, 352 MHz pulsed RF solid-state power amplifier to be utilized for feeding re-bunching cavities in proton linac, is in progress at ESS-Bilbao. This modular transmitter is based on in-phase combination of compact, water-cooled 2 kW RF power modules, each one consists of two combined LDMOS transistors in balanced configuration. The modules include individual bias control, measurement and supply circuits. Gate modulation is foreseen to increase efficiency in pulsed regime that is up to 3ms RF pulse width and 10% duty cycle. The 2 kW RF power module has been developed and the test results are discussed.

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WEPME015

High-gradient Test Results from a CLIC Prototype Accelerating Structure: TD26CC

damping, accelerating-gradient, target, vacuum

2285

W. Wuensch, A. Degiovanni, S. Döbert, W. Farabolini, A. Grudiev, J.W. Kovermann, E. Montesinos, G. Riddone, I. Syratchev, R. Wegner
CERN, Geneva, Switzerland
A. Solodko
JINR, Dubna, Moscow Region, Russia
B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

The CLIC study has progressively tested prototype accelerating structures which incorporate an ever increasing number of features which are needed for a final version installed in a linear collider. The most recent high power test made in the CERN X-band test stand, Xbox-1, is a of a CERN-built prototype which includes damping features but also compact input and output power couplers, which maximize the overall length to active gradient ratio of the structure. The structure’s high-gradient performance, 100 MV/m and low breakdown rate, matches previously tested structures validating both CERN fabrication and the compact coupler design.

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WEPME018

CERN Vacuum System Activities during the Long Shutdown 1: The LHC’s injector chain.

vacuum, ion, operation, gun

2291

J.A. Ferreira Somoza, P. Chiggiato
CERN, Geneva, Switzerland

During the long shutdown 1 (LS1), several maintenance, consolidation and upgrade activities have been carried out in LHC’s injector chain. Each machine has specific vacuum requirements and different history, which determine the present status of the vacuum components, their maintenance and consolidation needs. The present work presents the priorities agreed at the beginning of the LS1 period and their implementation. Of particular relevance are the interventions in radioactive controlled areas where several leaks due to stress corrosions stopped the operations in the past years. The strategy to reduce the collective dose is presented, in particular the use of remote controlled robots. An important part of the work performed during this period involves supporting other teams (acceptance tests, new equipment installation, etc.). Finally, as a result of the LS1 experience, a medium to long term strategy is depicted, focusing on the preparation of the next shutdown (LS2) and the integration of LINAC4 in the injector chain during the same period.

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WEPME024

Power Coupler Manufacturing and Quality Control at CPI

controls, cavity, SRF, target

2308

S.J. Einarson, T.A. Treado
CPI, Beverley, Massachusetts, USA

CPI has been designing and manufacturing fundamental power couplers for superconducting accelerators for over a dozen years. We have manufactured approximately 200 power couplers of 16 different designs. Power coupler frequencies have ranged from 175 MHz to 3.9 GHz and power levels have ranged from 5 kW to 500 kW average power. We have developed and qualified several key manufacturing processes including a high-RRR copper plating process and a titanium nitride coating process. In addition, we have established uniform quality control and inspection processes which ensure that the power couplers will meet the requirements for the intended use in superconducting accelerators. These processes have been developed, improved and/or qualified in collaboration with colleagues at superconducting accelerator facilities throughout the world. This paper will provide an overview of these critical manufacturing and quality control processes.

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WEPME035

Beam Loss Suppression by Improvement of Vacuum System in J-PARC RCS

injection, vacuum, ion, synchrotron

2338

J. Kamiya, M. Kinsho, S. Noshiroya, K. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

In high power beam accelerators, pressure of the beam line directly affects the amount of the beam loss. For example, in the early 1970’s in CERN’s Intersecting Storage Ring (ISR), the ion-induced pressure bump produced the fall-off of the beam current. 3GeV synchrotron (RCS) in J-PARC is no exception. RCS is one of the most high power beam accelerators in the world. It aims the 1 MW beam power, which corresponds to the average and peak beam current of 333 uA and about 10 A, respectively. In the present stage, the injection line called L3BT line (Linac to 3GeV Beam Transport line), is the section, where the pressure notably produces the beam loss. In this line, H⁻ beam from Linac was converted to H⁰ by charge stripping due to the interaction between H⁻ beam and the residual gas molecules. Such H⁰ was not bended by the injection septum magnets and directly hit the vacuum wall. We decided to add the vacuum pumps in this line to reduce the residual gas molecules. We will present the effectivity of the additional pumps on the basis of the measured results of the pressure improvement and the beam loss suppression.

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WEPME039

Leak Propagation Dynamics for the HIE-ISOLDE Superconducting Linac

vacuum, cryomodule, simulation, cathode

2351

G. Vandoni, M. Ady, M.A. Hermann, R. Kersevan, D.T. Ziemianski
CERN, Geneva, Switzerland

In order to cope with space limitations of existing infrastructure, the cryomodules of the HIE-Isolde superconducting linac feature a common insulation and beam vacuum, imposing the severe cleanliness standard of RF cavities to the whole cryostat. Protection of the linac vacuum against air-inrush from the three experimental stations through the HEBT lines relies on fast valves, triggered by fast cold cathode gauges. To evaluate the leak propagation velocity as a function of leak size and geometry of the lines, a computational and experimental investigation is being carried out at CERN. A 28 m long tube is equipped with strain gauges installed on thin-walled flanges, as well as fast reacting glow discharge and cold-cathode gauges. A leak is opened by the effect of a cutting pendulum, equipped with an accelerometer for data acquisition triggering, on a thin aluminium window followed by a calibrated orifice. The air inrush dynamics is simulated by Test-Particle Monte Carlo in the molecular regime and by Finite Elements fluid dynamics in the viscous regime.

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WEPME046

The HIE-Isolde Vacuum System

vacuum, cryomodule, controls, operation

2372

G. Vandoni, S. Blanchard, P. Chiggiato, K. Radwan
CERN, Geneva, Switzerland

The High Intensity and Energy Isolde (HIE-Isolde) project aims at increasing the energy and intensity of the radioactive ion beams (RIB) delivered by the present Rex-Isolde facility. Energy up to 10MeV/amu will be reached by a new post-accelerating, superconducting (SC) linac. Beam will be delivered via a HEBT to three experimental stations for nuclear physics. To keep the SC linac compact and avoid cold-warm transitions, the cryomodules feature a common beam and insulation vacuum. Radioactive ion beams require a hermetically sealed vacuum, with transfer of the effluents to the nuclear ventilation chimney. Hermetically sealed, dry, gas transfer vacuum pumps are preferred to gas binding pumps, for an optimized management of radioactive contamination risk during maintenance and intervention. The vacuum system of the SC-linac is isolated by two fast valves, triggered by fast reacting cold cathode gauges installed on the warm linac, the HEBT and the experimental stations. Rough pumping is distributed, while the HEBT turbomolecular pumps also share a common backing line. Slow pumpdown and ventilation of the cryomodules are studied to avoid particulate movement in the viscous regime.

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WEPME063

Pulsed Low Level Baseband RF Control of CH-Cavities for p-Linac at FAIR

controls, detector, proton, antiproton

2421

P. Nonn, U. Bonnes, C. Burandt, F. Hug, N. Pietralla
TU Darmstadt, Darmstadt, Germany
H. Klingbeil, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany
H. Klingbeil
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This project was supported by the BMBF under grant No. 05P09RDRB5 and by the Helmholtz International Center for FAIR (HIC for FAIR) funded by the State of Hesse within its LOEWE initiative.
At the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany a high intensity antiproton beam will be produced. To provide the necessary 70 mA proton beam a dedicated proton linac (p-Linac) is under construction. The main acceleration will be provided by 9 novel CH-type cavities, of which 6 will be coupled in pairs to share the same klystron. To test the rf properties of these novel cavities, a test stand is under construction. An rf control system for the pulsed operation of these cavities has been developed at TU Darmstadt. It is based upon the digital cw rf control that is successfully in operation as part of the S-DALINAC at IKP Darmstadt. The latest developments will be presented.

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WEPME065

European XFEL RF Gun Commissioning and LLRF Linac Installation

LLRF, gun, klystron, cryomodule

2427

J. Branlard, G. Ayvazyan, V. Ayvazyan, L. Butkowski, M.K. Grecki, M. Hoffmann, F. Ludwig, U. Mavrič, S. Pfeiffer, H. Schlarb, Ch. Schmidt, H.C. Weddig, B.Y. Yang
DESY, Hamburg, Germany
S. Bou Habib, K. Czuba, M. Grzegrzółka, E. Janas, J. Piekarski, I. Rutkowski, R. Rybaniec, D. Sikora, L.Z. Zembala, M. Żukociński
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
W. Cichalewski, D.R. Makowski, A. Mielczarek, P. Perek, A. Piotrowski, T. Pożniak
TUL-DMCS, Łódź, Poland
S. Korolczuk, I.M. Kudla, J. Szewiński
NCBJ, Świerk/Otwock, Poland
K. Oliwa, W. Wierba
IFJ-PAN, Kraków, Poland

The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed linac and is scheduled to deliver its first beam in 2016. The first component of its accelerator chain, the RF gun, was installed in fall of 2013 and its commissioning is underway. This contribution gives an update on the low level radio frequency (LLRF) system development and installation for the XFEL. In particular, the installation, performance and conditioning results of the RF gun are presented. The subsequent steps toward LLRF components mass-production, testing and installation for the XFEL linac are also explained.

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WEPME070

Plans for the Implementation of an Intra-pulse Feedback on the Fermi Linac LLRF System

feedback, LLRF, klystron, controls

2441

M. Milloch, A. Fabris, F. Gelmetti, M. Predonzani
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

FERMI is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The 1.5 GeV S-band linac is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, sixteen accelerating sections and the RF deflectors. The requirements on beam quality impose tight specifications on the stability of the electromagnetic fields that can be achieved only installing high reliable and high performance state of the art LLRF systems. While these requirements are presently met by the system installed, the on-going upgrade of the processing board with the final one will allow to add new functionalities of the system. One of the possible developments is the implementation of an intra-pulse feedback that will allow to apply the corrections inside the RF pulse. This paper provides an overview of the additional benefits that could be achieved and discusses the requirements and the constraints for the implementation in the machine.

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WEPME072

Performance of the Digital LLRF System at the cERL

LLRF, cavity, controls, feedback

2447

F. Qiu, D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura
KEK, Ibaraki, Japan

A digital low-level radio frequency (LLRF) system has been developed and evaluated at compact Energy Recovery Linac (cERL) in High Energy Accelerator Research Organization (KEK), Japan. A total of three two-cell cavities were installed for the injector, and two nine-cell cavities were installed for the main linac. The required RF stabilities for these cavities are 0.1% rms in amplitude and 0.1° rms in phase. To satisfy these requirements, we survey feedback parameters such as the proportional and integral (PI) gains. Furthermore, we evaluated the beam energy fluctuation due to the vector-sum controlling error between the cavities injectors 2 and 3. Finally, we present the performance of the LLRF system that was realized in the beam commissioning. This paper describes the current status of the LLRF system.

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WEPME073

Performance of RF System for Compact-ERL Main Linac at KEK

feedback, cavity, controls, LLRF

2450

T. Miura, M. Akemoto, A. Akiyama, D.A. Arakawa, S. Fukuda, H. Honma, H. Katagiri, T. Matsumoto, H. Matsushita, S. Michizono, H. Nakajima, K. Nakao, F. Qiu, H. Sakai, T. Shidara, T. Takenaka, K. Umemori, Y. Yano
KEK, Ibaraki, Japan

The construction of compact ERL in the first stage has been completed in the end of 2013. The rf commissioning in main-linac has been started. The main-linac consists of two nine-cell cavities. The loaded Q is high, ~10⁷. As the rf power sources, a solid state power amplifier and an inductive output tube (IOT) has been used for two cavities, respectively. The RF field and tuner have been successfully controlled by using micro-TCA digital feedback board. This paper reports about the RF commissioning and the performance.

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WEPRI006

High Power RF Input Couplers and Test Stand for the BERLinPro Project

cavity, booster, SRF, coupling

2487

V.F. Khan, W. Anders, A. Burrill, J. Knobloch, A. Neumann
HZB, Berlin, Germany

Funding: Work supported by German Federal Ministry of Education and Research, Land Berlin, and grants of the Helmholtz Association
The BERLinPro project, under construction at HZB, is a 100 mA, 50 MeV superconducting RF (SRF) energy recovery linac (ERL) being built to study the accelerator physics of operating a high current SRF ERL. For this high current operation, coaxial RF power couplers capable of handling 130 kW of power, c.w. at 1.3 GHz are required for both the SRF gun and booster cavities. In order to achieve this power level a coupler has been designed based on the high power coupler currently in use at the KEK-cERL. A key improvement that was made to the coupler was the modification of the coupler tip, termed a golf-tee. This modification is incorporated so as to achieve the desired coupling, Qext ~10⁵, with minimal coupler penetration into the beampipe. Herein, we discuss the RF design and properties of the high-power coaxial coupler for the gun as well as booster cavity of BERLinPro, along with the design of the test stand for conditioning a pair of couplers.

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WEPRI013

Investigation of Cryomodules for the Mainz Energy-recovering Superconducting Accelerator MESA

cryomodule, HOM, operation, higher-order-mode

2505

F. Schlander, K. Aulenbacher, R.G. Heine, D. Simon
IKP, Mainz, Germany
A. Arnold
HZDR, Dresden, Germany

Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA"
For the multiturn accelerator MESA it is planned to employ superconducting technology for the main linac, which is supposed to provide an energy gain of 50 MeV per turn. As continuous wave operation is mandatory for the experiments, it is important to minimise the cryogenic losses, hence to find cavities and the corresponding cryomodule meeting the framework conditions for the accelerator. The findings and the current statuts will be reported.

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WEPRI016

Status of the Vertical Testing of the XFEL Third Harmonic Cavity Series

cavity, HOM, coupling, operation

2508

J.F. Chen, M. Bertucci, A. Bosotti, M. Fusetti, C. Maiano, P. Michelato, L. Monaco, M. Moretti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy

The prototype cavities of the XFEL 3rd harmonic system at the XFEL injector have been tested vertically before their final integration into the He tank. The Vertical Test facility has been upgraded in preparation of the series and the results so far obtained are presented.

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WEPRI018

Status of the Fabrication of the XFEL 3.9 GHz Cavity Series

cavity, status, vacuum, gun

2512

C. Maiano, M. Bertucci, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, M. Moretti, C. Pagani, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy

The third harmonic system at 3.9 GHz of the European XFEL (E-XFEL) injector section will linearize the bunch RF curvature, induced by first accelerating module, before the first compression stage and it is a joint INFN and DESY contribution to the project. This paper presents the status of the fabrication of the 3.9 GHz cavity series in view of the XFEL injector commissioning in 2015.

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WEPRI020

Mechanical Analysis of the XFEL 3.9 GHz Cavities in support of PED Qualification

cavity, simulation, superconducting-cavity, controls

2515

M. Moretti, P. Pierini
INFN/LASA, Segrate (MI), Italy
A. Schmidt
DESY, Hamburg, Germany

We present the FEA stress analysis under different mechanical conditions of the XFEL 3.9 GHz superconducting cavities. The analysis is being performed in support of the necessary qualification according to the Pressure Equipment Directive European Norms, for the operating conditions set in the European XFEL project.

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WEPRI026

Mechanical Vibration Search of Compact ERL Main Linac Superconducting Cavities in Cryomodule

cavity, LLRF, operation, cryomodule

2531

M. Satoh, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

In 2014, we will start the beam operation in Compact ERL(cERL) by using main linac cryomodule, which contained the two 9-cell cavities. In principle, thanks to the mechanism of energy recovery, the input power of main linac of cERL is very small even if the beam current will be higher than 100mA. Therefore, the coupling is very weak. However, this coupling is perfectly not matched to the unloaded Q-value of the superconducting cavity like 1x10¹⁰. The minimum input power will be restricted by the cavity detuning due to the microphonics from the cryomodule itself. We designed the lower loaded Q-valued of (1-4)x10⁷ to reduce the effect of the michrophonics from the expected outer disturbance At present, we successfully suppressed the michrophonics to meet our requirement. However we found the enhancement of the detuning angle when we did not optimize the feedback loop of LLRF. This enhancement will be expected coming from the mechanical resonance frequencies of cavity and/or cryomodule. In this paper, we reported the correlation between the measured microphincs spectrum with LLRF in a beam operation and the results of the measured resonance frequencies spectrum at the test bench.

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WEPRI027

Performance Evaluation of ERL Main Linac Tuner

cavity, operation, controls, feedback

2534

K. Enami, D.A. Arakawa, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

cERL project is now progressing. We are carrying on R&D for cERLmain linac consisted of 1.3GHz superconductive cavity. We evaluate slide jack tuner, which is component part of cryomodule. A slide jack tuner has 2 mechanism to tune frequency. One is slide jack mechanism that tunes roughly and the other is piezo mechanism that tunes finely. We carried out basic experiment and cold experiment. We finally confirmed that slide jack tuning system can tuning to target frequency 1.3GHz.

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WEPRI028

Operation Status of Compact ERL Main Linac Cryomodule

operation, radiation, cavity, cryomodule

2537

K. Umemori, K. Enami, T. Furuya, S. Michizono, T. Miura, F. Qiu, H. Sakai, M. Satoh, K. Shinoe
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

We have developed a main linac cryomodule, in which two nine-cell HOM damped SRF cavities were mounted, for the Compact ERL (cERL) project in Japan. The main linac cryomodule is operated by a 2K refrigerator system, whose cooling ability is 80W. RF power is fed to each cavity from an IOT or a solid state amplifier. Amplitude and phase of RF stabilization is done by using a digital LLRF system. Cavity resonant frequency is controlled by using mechanical and piezo tuners. Before beam operation, performance test of the cryomodule has been carried out. Generally the cryomodule works well, but heavy field emission is rather problem. After construction of cERL circulation ring, we have a plan to do first beam operation with energy recovery mode, in this winter. Electron beam are accelerated up to 20 MeV. Heavy heat load to 2K Helium, caused by field emission, restrict cavity operation voltage. We report about a series of performance tests and a first experiment from beam operation.

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WEPRI036

Fabrication Design of QWR and HWR Cryomodules

cryomodule, vacuum, cavity, cryogenics

2555

W.K. Kim, H. Kim, H.J. Kim, Y. Kim, M. Lee, G.-T. Park
IBS, Daejeon, Republic of Korea

The superconducting linac of RAON consists of five types of cryomodules. The cryomodules host QWR, HWR1, HWR2, SSR1, and SSR2 superconducting cavities. The cryomodules will be operated at 2K in order to test the performance of the superconducting cavities. The design of the cryomodule components is based on thermal shield to prevent incoming heat, two-phase pipe to supply superfluid helium, vacuum vessel for the formation of the internal vacuum, supporter parts for alignment and keeping structure, and magnetic shield to prevent external magnetic field. The detailed fabrication design of the cryomodules will be presented in this paper.

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WEPRI039

LIPAc SRF Linac Couplers Conditioning

vacuum, SRF, operation, electron

2562

D. Regidor, I. Kirpitchev, J. Mollá, P. Méndez, M. Weber, C. de la Morena
CIEMAT, Madrid, Spain
S. Chel, M. Desmons, G. Devanz, H. Jenhani
CEA/IRFU, Gif-sur-Yvette, France
H. Dzitko
CEA, Pontfaverger-Moronvilliers, France

The LIPAc SRF Linac is a cryomodule with eight superconducting HWR cavities at 175 MHz powered by RF couplers capable of transmitting up to 200 kW in CW. To prepare the couplers for operation, cleaning and high power RF processing are needed. When performed, the couplers will be ready for integration in the cryomodule. The Couplers Test Bench has been designed to perform the RF conditioning by pairs, providing good matching, low losses and the required UHV level. To preserve the cleanliness of the internal surfaces, after the test bench manufacturing, an ISO5 clean room has been used for the vacuum parts assembly. The size and number of particles was carefully controlled during the assembly process. The RF conditioning was performed at the IFMIF-EVEDA RF Integration Facility using the Prototype RF Module in travelling wave and standing wave modes. The process started with short pulses at low power and finished when full power CW was reached. Vacuum, multipacting, arcs and matching were continuously monitored to control the process avoiding damages. An overview of the process applied to the prototypes and the RF conditioning results are presented in this paper.

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WEPRI046

Commissioning of the ERL Cryomodule on ALICE at Daresbury Laboratory

cryomodule, cryogenics, cavity, LLRF

2583

A.E. Wheelhouse, R.K. Buckley, S.R. Buckley, P.A. Corlett, L.S. Cowie, P. Goudket, A.R. Goulden, L. Ma, P.A. McIntosh, A.J. Moss, S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The ERL cryomodule with two identical 7-cell, 1.3 GHz cavities developed as part of a international collaborative program has been installed in the linac stage on the ALICE (Accelerators and Lasers in Combined Experiments) facility at Daresbury Laboratory replacing the existing 9-cell cryomodule. The cavities have been cooled to 2 K and commissioning of the cryomodule is underway. This paper describes the conditioning and the characterisation tests performed on the two superconducting RF cavities.

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WEPRI060

Investigation of Thermocurrents Limiting the Performance of Superconducting Cavities

cavity, shielding, niobium, framework

2621

R.G. Eichhorn, C.G. Daly, F. Furuta, A. Ganshin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

As the surface resistance of superconducting cavities approach the theoretical limits parasitic effects limiting the performance came into focus of current research. One of these effects is that the quality factor of a cavity is impacted by the cooldown rate. We will present results from recent investigations on thermocurrents, driven by the temperature difference between the two material interfaces between the superconducting Niobium cavity and its Titanium helium-vessel, leading to the presence of a magnetic field while the cavity transits to the superconducting state.

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WEPRI061

Cornell's Main Linac Cryomodule for the Energy Recovery Linac Project

cavity, cryomodule, vacuum, alignment

2624

R.G. Eichhorn, B. Bullock, J.V. Conway, B. Elmore, F. Furuta, Y. He, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, T.I. O'Connel, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R&D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities (2•1010) and high beam currents (100 mA accelerated plus 100 mA decelerated) are targeted. We will present the status of the main linac cryomodule (MLC) fabrication and the findings on the cavity performance and component testing.

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WEPRI062

The Joint High Q0 R&D Program for LCLS-II

cavity, cryomodule, SRF, factory

2627

M. Liepe, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, G.H. Hoffstaetter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
A.C. Crawford, A. Grassellino, A. Hocker, O.S. Melnychuk, A. Romanenko, A.M. Rowe, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA
R.L. Geng, A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA
M.C. Ross
SLAC, Menlo Park, California, USA

The superconducting RF linac for LCLS-II calls for 1.3 GHz 9-cell cavities with an average intrinsic quality factor Q0 of 2.7·10¹⁰ at 2K and 16 MV/m accelerating gradient. A collaborative effort between Cornell University, FNAL, and JLab has been set up with the goal of developing and demonstrating a cavity treatment protocol for the LCLS-II cavities meeting these specifications. The high Q0 treatment protocol is based on nitrogen doping of the RF surface layer during a high temperature heat treatment. This novel SRF cavity preparation was recently developed at FNAL and shown to result in SRF cavities of very high Q0 at 2K with an increase in Q0 from low to medium fields. N-doped single cell cavities at Cornell, FNAL, and JLab routinely exceed LCLS-II specification. 9-cell N-doped cavities at FNAL achieve an average Q0(T=2K, 16 MV/m) of ≈ 3.4·10¹⁰ with an average quench field of ≈ 19 MV/m, meeting therefore overall with good margin the LCLS-II specification.

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WEPRI063

Flux Trapping in Nitrogen-Doped and 120 C Baked Cavities

cavity, SRF, vacuum, niobium

2631

D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: United States Department of Energy
It is well known that external magnetic fields can cause higher residual resistance in superconducting RF cavities if the field is present during cooldown. However, the effect of cavity preparation and surface mean free path on the resulting residual resistance from magnetic field is less well studied. In this paper, we report on recent studies at Cornell in which two SRF cavities (one nitrogen-doped and one 120oC baked) were cooled through Tc in an applied uniform external magnetic field. Trapped flux and residual resistance were measured for a variety of cooldowns and applied magnetic fields. It was found that the residual resistance due to trapped flux in the nitrogen-doped cavity was three times larger than in the 120oC baked cavity.

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WEPRI106

Design of Cryomoudles for RAON

cryomodule, cavity, vacuum, ion

2746

Y. Kim, C. Choi, H.M. Jang, Y.W. Jo, H.J. Kim, W.K. Kim, M. Lee
IBS, Daejeon, Republic of Korea

The accelerator will be built in Korea called RAON has four kinds of superconducting cavities such as QWR, HWR1, SSR1 and SSR2, and those cavities are operating in 2 K. The fabrication design for the SSR1 and SSR2 cryomodules are reported in this paper. The issues included in the paper are thermal and structural analysis results for the components such thermal shield, support post, two phase pipe, and so on.

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WEPRI109

The ESS Cryogenic System

cryogenics, cryomodule, target, neutron

2756

P. Arnold, J. Fydrych, W. Hees, J.M. Jurns, X. Wang, J.G. Weisend
ESS, Lund, Sweden

Cryogenic cooling is vital for large sections at ESS. The ESS cryogenic system comprises three separate helium refrigeration/liquefaction plants and an extensive cryodistribution system. Mainly there is a 2.0 GeV proton linac using superconducting RF cavities operating at 2 K. In addition to cooling the SRF cavities, cryogenics is also used for the cold hydrogen moderator surrounding the target. There is also a cryogenic installation associated with the site acceptance testing of the ESS cryomodules. ESS furthermore uses both liquid helium and liquid nitrogen in a number of the neutron instruments. The test stand cryoplant will as well provide liquid helium for neutron instrument sample environments and comprise a helium purification unit. Together with the gas management, helium recovery and a considerable cold and warm storage system, cryogenics form a substantial part of ESS. This paper describes the current conceptual design of the ESS cryogenic system including the expected heat loads and operating modes for the linac cryoplant. Challenges associated with the required high efficiency, reliability and turn-down capability will be discussed.

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WEPRI110

The HNOSS Horizontal Cryostat and the Helium Liquefaction Plant at FREIA

cavity, cryogenics, operation, vacuum

2759

R. Santiago Kern, T.J.C. Ekelöf, K.J. Gajewski, L. Hermansson, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
P. Bujard, N.R. Chevalier, T. Junquera, J.P. Thermeau
Accelerators and Cryogenic Systems, Orsay, France

A horizontal cryostat to test superconducting cavities and magnets at liquid helium temperatures is installed at FREIA (Facility for REsearch Instrumentation and Accelerator development) at Uppsala University, Sweden. The cryostat allows full testing of superconducting spoke and elliptical accelerating cavities without the need of a specialized cryomodule per cavity. Because horizontal cryostats are custom-built, their number in the accelerator world is very limited. The FREIA horizontal cryostat is one of a kind as it has been designed to be versatile: it is able to house either two ESS double-spoke, or two ESS/TESLA type elliptical cavities, or superconducting magnets or a combination of these with all the ancillary equipment (power couplers, tuners, etc) and test them at the same time, reducing installation time but requiring extra design effort and cryogens supply. In order to achieve this, a helium liquefier with a capacity of 140 l/h delivers liquid helium to the horizontal cryostat while the return gases are directed towards a recovery system, connected in closed loop with the liquefier.

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THOAB02

Options for UK Technetium-99m Production using Accelerators

target, cyclotron, neutron, proton

2815

H.L. Owen
UMAN, Manchester, United Kingdom
J.R. Ballinger
KCL, London, United Kingdom
J. Buscombe
Addenbrooke's Hospital, Cambridge, United Kingdom
R.J. Clarke
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
E. Denton
Norfolk and Norwich University Hospital, Norwich, United Kingdom
B. Ellis
Central Manchester University Hospital, Manchester, United Kingdom
G.D. Flux
Royal Marsden NHS Foundation Trust, London, United Kingdom
L. Fraser
PHE, London, United Kingdom
B.J. Neilly
University of Glasgow, Glasgow, United Kingdom
A. Paterson
The Society of Radiographers, London, United Kingdom
A. Perkins
University of Nottingham, Nottingham, United Kingdom
A.F. Scarsbrook
Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Leeds, United Kingdom

Recent and ongoing shortages in reactor-based supplies of Molybdenum-99 for hospital production of the important medical radioisotope Technetium-99m have prompted the re-examination of the alternative production methods using conventional and laser-based particle accelerators. At present the UK has no domestic Technetium-99m production and relies exclusively on Technetium-99m generators manufactured overseas; the National Health Service, with professional partners, is therefore examining the options for domestic production to increase security of supply. In this paper we review the accelerator-based methods from a UK perspective, and outline the most promising methods for short- and medium-term supply, which include low-energy cyclotron and photonuclear reaction routes using enriched Molybdenum-100 targets.

Slides THOAB02 [38.942 MB]

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THOBB01

Pursuing the Origin and Remediation of Low Q0 observed in the Original CEBAF Cryomodules

cryomodule, shielding, cavity, SRF

2828

R.L. Geng, J.F. Fischer, C.E. Reece, A.V. Reilly
JLab, Newport News, Virginia, USA
F.S. He, Y.M. Li
PKU, Beijing, People's Republic of China

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We report on results of a new investigation into the Q0 degradation phenomenon observed in original CEBAF cavities when assembled into cryomodules. As a result, the RF dissipation losses increased by roughly a factor of two. The origin of the degradation, first observed in 1994, has remained unresolved up to current period, despite much effort. Recently, a new investigation has been launched, taking advantage of the latest cryomodule to undergo refurbishment. Systematic measurements are conducted with respect to the magnetic shielding effects of the double-layer shields and the magnetic properties of various components within the inner shield. This resulted in the new discovery of strongly magnetized strut springs as a major source of remnant magnetic flux near a cavity inside of all magnetic shielding. New springs with superior magnetic properties have been found, evaluated and implemented into the current cryomodule. In this contribution, we will review the data accumulated so far. Options for complete Q0 preservation of assembled cavities and possible Q0 remediation for those 330 cavities already installed in CEBAF will be presented.

Slides THOBB01 [16.521 MB]

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THPRO013

FERMI Status Report

FEL, laser, electron, experiment

2885

M. Svandrlik, E. Allaria, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, M. Coreno, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, G. De Ninno, P. Delgiusto, A.A. Demidovich, S. Di Mitri, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, E. Ferrari, P. Finetti, L. Fröhlich, P. Furlan Radivo, G. Gaio, D. Gauthier, F. Gelmetti, L. Giannessi, M. Kiskinova, S. Krecic, M. Lonza, N. Mahne, C. Masciovecchio, M. Milloch, F. Parmigiani, G. Penco, L. Pivetta, O. Plekan, M. Predonzani, E. Principi, L. Raimondi, P. Rebernik Ribič, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Zangrando, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, Italy, consists of two FEL lines. The FEL-1 facility, covering the wavelength range between 20 and 100 nm, was officially opened to external users. The shorter wavelength range, between 20 and 4 nm, is covered by the FEL-2 line, a double stage cascade operating in the “fresh bunch injection” mode, which is still under commissioning. We will report on the different FEL-1 operation modes that can be offered for users and assess the performance of the facility. The progress in the commissioning of FEL-2 will then be addressed, in particular reporting the performance attained at the lower wavelength limit; this aspect is of great interest for the user’s community of the FERMI seeded FEL since it allows to carry out experiments below the carbon K-edge.

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THPRO018

Electron-Magnetic-Phase Mixing in a Linac-driven FEL to Suppress Microbunching in the Optical Regime and Below

electron, FEL, laser, radiation

2894

S. Di Mitri, S. Spampinati
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea
S. Spampinati
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Control of microbunching instability is a fundamental requirement in modern high brightness electron linacs, in order to prevent malfunction of beam optical diagnostics and contamination in the generation of coherent radiation, such as free electron lasers. We present experimental control and suppression of microbunching instability-induced optical transition radiation by means of particles’ longitudinal phase mixing in a magnetic chicane*. In presence of phase mixing, the intensity of the beam-emitted coherent optical transition radiation is reduced by one order of magnitude and brought to the same level provided, alternatively, by beam heating. The experimental results are in agreement with particle tracking and analytical evaluations of the instability gain. A discussion of applications of magnetic phase mixing to the generation of quasi-cold high-brightness ultra-relativistic electron beams is finally given.
* S. Di Mitri and S. Spampinati, Phys. Rev. Lett. 112, 134802 (2014)

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THPRO019

Current Status of PAL-XFEL Project

undulator, klystron, quadrupole, cavity

2897

H.-S. Kang, K.W. Kim, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea

The PAL-XFEL, a 0.1-nm hard X-ray FEL facility consisting of a 10-GeV S-band linac, is being constructed in Pohang, South Korea. The installation of linac, undulator, and beam line will be completed by 2015. Its building construction is at its peak moment to be completed by December 2014. The major procurement contract was made in 2013 for the critical components of S-band linac modules and hard X-ray undulators. The commissioning will start in January 2016. We hope the first lasing will be achieved in early 2016.

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THPRO020

Linac Lattice Optimization for PAL-XFEL Hard X-ray FEL Line

lattice, FEL, simulation, emittance

2900

H. Yang, J.H. Han, H.-S. Kang, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This work is supported by MSIP, Korea.
PAL-XFEL is designed to generate 1 – 0.06-nm FEL in hard x-ray FEL line. The linac for hard x-ray generates 10-GeV, 200-pC, and 3-kA electron beam. It consists of accelerating columns, three bunch compressors, an X-band linearizer, and dog-leg line. We conduct ELEGANT simulations to obtain the optimized lattice for hard x-ray line. The candidates of the optimized lattice are obtained by Multi-Objective Genetic Algorithm (MOGA) whose objectives are the FEL saturation power and length. These are evaluated with their error tolerances. Error tolerances are obtained by two methods of error simulations. First, the linear interpolation method is conducted in order to determine the machine tolerance. Also, we find out the dominant machine parameters to increase the beam jitter by this method. Second, the error simulations with random errors of machine parameters are conducted to verify the results of the linear interpolation method and calculate beam jittering levels. In this paper, we present the details of the optimized linac lattice for hard x-ray FEL. Also, we present the procedure of the linac lattice optimization.

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THPRO025

Conceptual Design of a X-FEL Facility using CLIC X-band Accelerating Structure

FEL, klystron, simulation, gun

2914

A.A. Aksoy, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
D. Angal-Kalinin, J.A. Clarke
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.J. Boland
SLSA, Clayton, Australia
G. D'Auria, S. Di Mitri, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
M. Doğan
Dogus University, Istanbul, Turkey
T.J.C. Ekelöf, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
W. Fang, Q. Gu
SINAP, Shanghai, People's Republic of China
A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
Z. Nergiz
Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey

Within last decade a linear accelerating structure with an average loaded gradient of 100 MV/m at 12 GHz has been demonstrated in the CLIC study. Recently, it has been proposed to use the CLIC structure to drive an FEL linac. In contrast to CLIC the linac would be powered by klystrons not by a drive beam. The main advantage of this proposal is achieving the required energies in a very short distance, thus the facility would be rather compact. In this study, we present the conceptual design parameters of a facility which could generate laser photon pulses covering the range of 1-75 Angstrom. Shorter wavelengths could also be reached with slightly increasing the energy.

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THPRO026

Design Parameters and Current Status of the TARLA Project

FEL, electron, undulator, radiation

2918

A.A. Aksoy, Ö. Karslı, C. Kaya, E. Kazancı, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
P. Arıkan
Gazi University, Faculty of Arts and Sciences, Teknikokullar, Ankara, Turkey
S. Özkorucuklu
Istanbul University, Istanbul, Turkey

Funding: Work is supported by Ministry of Development of Turkey with Grand No: DPT2006K-120470
The Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) will operate two InfraRed Free Electron Lasers (IR-FEL) covering the range of 3-250 microns. The facility will consist of an injector fed by a thermionic triode gun with two-stage RF bunch compression, two superconducting accelerating ELBE modules operating at continuous wave (CW) mode and two independent optical resonator systems with different undulator period lengths. The electron beam will also be used to generate Bremsstrahlung radiation. In this paper, we discuss design goals of the project and present status and road map of the project.
On behalf of TARLA Team

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THPRO027

Turkish Accelerator Center: The Status and Roadmap

FEL, electron, proton, factory

2921

A.A. Aksoy, O. Yavaş, H.D. Duran Yıldız
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
B. Akkus, S. Özkorucuklu, L.S. Yalcin
Istanbul University, Istanbul, Turkey
H. Aksakal, Z. Nergiz
Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey
E. Algin
Eskisehir Osmangazi University, Eskisehir, Turkey
O. Cakir
Ankara University, Faculty of Sciences, Ankara, Turkey

Funding: Ankara University
Turkish Accelerator Center (TAC) Project has started with support of the Ministry of Development (MD) of Turkey under the coordination of Ankara University. TAC is an inter-university collaboration with 12 Turkish Universities. An IR FEL facility (TARLA) based on Sc linac with 15-40 MeV energy under construction in Ankara as the first facility of TAC. It is expected that the TARLA facility will be commissioning in 2017. In addition to the TARLA, it is planned that Turkish Accelerator Center will include a third generation synchrotron radiation facility based on 1-3 GeV electron synchrotron (TAC SR), a fourth generation SASE FEL facility based on up to 5 GeV electron linac (TAC SASE FEL), a multi-purpose proton accelerator facility with 3 MeV-2 GeV beam energy (TAC PAF) and an electron-positron collider as a super charm factory (TAC PF). Construction phase of the proposed GeV scale accelerator facilities will cover next decade. In this presentation, main goals and road map of Turkish Accelerator Center will be explained. (http://thm.ankara.edu.tr)
*On behalf of TAC collaboration

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THPRO028

Bunch Compressor Design for CLIC Drive Beam

gun, cathode, linear-collider, collider

2924

A.A. Aksoy
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
J. Esberg, D. Schulte
CERN, Geneva, Switzerland

The drive-beam linac which is required for generation RF power at Compact Linear Collider (CLIC) has to accelerate an electron beam with 8.4 nC per bunch up to 2.4 GeV in almost fully loaded structures. The required beam stability in both transverse and longitudinal directions are of concern for such a high bunch charge. We present different bunch compressor designs for the Drive Beam and compare their performance including the effects beam energy and phase jitters.

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THPRO029

A Front End for the CLARA FEL Test Facility at Daresbury Laboratory

gun, dipole, bunching, emittance

2927

P.H. Williams, D. Angal-Kalinin, J.A. Clarke, B.D. Fell, J.K. Jones, J.W. McKenzie, B.L. Militsyn
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The next step towards the full CLARA facility is installation of the CLARA front end to comprise a 2m S-band linac section after the photoinjector gun. This will be suitable for both the velocity bunching and standard booster modes of CLARA. An S-bend will also be installed to deflect the beam into the current VELA line, enabling delivery of higher energy beams to two existing user areas. The current photoinjector beam diagnostics section can then be used to test a High Repetition Rate electron gun currently under development. We describe the proposed CLARA front end design. We define two beam dynamics working points for CLARA, one working point for sending beam from the CLARA Front End to VELA, and one working point to feed an interim user station prior to CLARA full construction in the straight-on position.

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THPRO034

Design of the LCLS-II Electron Optics

undulator, quadrupole, electron, optics

2940

Y. Nosochkov, P. Emma, T.O. Raubenheimer, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Work supported by the US Department of Energy Contract DE-AC02-76SF00515.
The LCLS-II project is a high repetition rate, high average brightness free-electron laser based on the existing facilities at the SLAC National Accelerator Laboratory. The LCLS-II will be driven by a new CW superconducting RF (SCRF) 4-GeV linac replacing the existing Cu-linac in the 1st km of the linac tunnel. The SCRF linac will include chicanes for providing full compression of the electron bunch length. After the linac, the electron beam will be directed into the existing 2-km bypass line connecting to the Beam Switch Yard (BSY), where a new spreader system will allow a high rate bunch-by-bunch deflection into the hard X-ray (HXR) or soft X-ray (SXR) transport lines, or towards the BSY high power dump. The HXR line will include a new variable gap undulator replacing the existing LCLS-I undulator and will reuse the existing LCLS-I linac-to-undulator and dump transport lines. The SXR will require a new transport line sharing the same tunnel with the HXR and will include a new variable gap undulator. Overview of the electron beam transport and the optics design are presented.

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THPRO045

Design and Construction of a Thermionic Cathode RF Electron Gun for Iranian Light Source Facility

gun, electron, simulation, emittance

2965

A. Sadeghipanah, H. Ghasem, J. Rahighi, Kh.S. Sarhadi
ILSF, Tehran, Iran

We present a program for the design and construction of a thermionic cathode RF gun to produce bright electron beams, consisting in the first step toward the possible development of S band linac based pre-injector at Iranian Light Source Facility (ILSF). The program is aimed at the goal to attain a beam quality as requested by ILSF. As a first step within this mainstream, we are currently developing a thermionic cathode side coupling RF electron gun which is expected to deliver 100 pC bunches with emittances below 2 mm-mrad at 2.5 MeV. We report the performed simulation and design activity, as well as cold test results of first fabricated prototype, which are in good agreement with simulation results.

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THPRO047

Linac Design for the Proposed NSRRC THz/VUV FEL Facility

electron, bunching, optics, emittance

2971

N.Y. Huang, W.K. Lau, A.P. Lee
NSRRC, Hsinchu, Taiwan
A. Chao, J. Wu
SLAC, Menlo Park, California, USA
C.H. Chen
NTHU, Hsinchu, Taiwan

A driver linac based on a photocathode RF gun injector system for a proposed free electron laser facility at National Synchrotron Radiation Research Center (NSRRC) in Taiwan is under study. This facility is designed to be operated in two modes, one for the VUV application and one for the THz application to fulfil the user needs. Generally the VUV radiation prefers a low emittance, high peak current beam free from collective instability during acceleration and magnetic pulse compression, whereas the THz radiation needs a moderate charge in hundred femtosecond bunch length free from space charge degradation in a transport line. In this paper, the schemes of bunch compression as well as the strategy to optimize and control of the beam quality will be presented.

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THPRO050

Study of a THz/VUV Free Electron Laser Facility in Taiwan

FEL, laser, radiation, undulator

2980

N.Y. Huang, M.C. Chou, C.-S. Hwang, W.K. Lau, A.P. Lee
NSRRC, Hsinchu, Taiwan
A. Chao, J. Wu
SLAC, Menlo Park, California, USA
C.H. Chen, Y.-C. Huang
NTHU, Hsinchu, Taiwan
X.M. Yang
DICP, Dalian, People's Republic of China

A free electron laser (FEL) facility aimed for VUV and THz radiation is being studied at National Synchrotron Radiation Research Center (NSRRC) in Taiwan. Strong consideration has been given to minimize the cost by making maximum use of existing hardware at NSRRC. One unique consideration is to use an existing undulator for the dual functions of the THz radiator and the modulator of a HGHG section. Design emphasizes versatility of operation and beam quality control and compensation of nonlinearities, with a vision that it will allow as much as possible future upgrades as well as later R&D of FEL physics. The polarization control of the THz radiation provides novel application for the users. The facility is to be housed in the existing 38-m by 5-m tunnel of the TPS Linac Test Laboratory.

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THPRO072

Field Parametrisation for the ESS Superconducting Cavities

cavity, simulation, space-charge, HOM

3044

T. Lindqvist
Lund University, Lund, Sweden
E. Laface
ESS, Lund, Sweden

Here we present a method for constructing a parametrization of the electric field in the superconducting elliptic cavities of the ESS linac. The parametrization is done by replicating the electric field from measured data using trigonometric and exponential functions. The field generated by the parameters exhibits a mean error of 0.28% ( maximum error of 3.8% and s.t.d. error 1.1%), with the advantage of only taking up a fraction of the required data. The field in the entire cavity is extrapolated by combining the Maxwell equations with the parametrized form of the field. We also present particle simulations based on the parametrization model to showcase some typical accelerator behaviour. Additionally we present a small extension of the parametrization method to also model spoke cavities.

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THPRO073

Longitudinal Acceptance Evaluation from Hamiltonian

cavity, simulation, acceleration, lattice

3047

E. Laface
ESS, Lund, Sweden

An RF cavity is designed around a reference particle; if the energy or the phase of a real particle are too far from the reference, the particle is lost. The widest area of energy-phase that allows a particle to be transported by the cavity is called acceptance of the cavity. In simulations the acceptance is evaluated tracking several particles with different energies and phases and marking when a particle is transmitted or lost. This process can be time consuming because of the large amount of tracked particles requested to characterise the cavity acceptance. In this paper we propose an alternative method to evaluate the acceptance studying directly the Hamiltonian associated to the cavity.

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THPRO074

Characterization of the Longitudinal Wakefields in the MAX IV Linac

wakefield, simulation, gun, FEL

3050

O. Karlberg, F. Curbis, S. Thorin, S. Werin
MAX-lab, Lund, Sweden

In the second part of 2014, the 3GeV linac at the MAX IV laboratory will enter its commissioning stage. Equipped with two guns, the linac will act as a full energy injector for the two storage rings and at the same time provide high brightness pulses to a Short Pulse Facility (SPF). Compression in the linac is done in two double achromats with fixed R56 that relies upon the RF phase introduced energy chirp, which in this case is strongly enhanced by the longitudinal wakefields. Since the longitudinal wakefields plays a major role in the compression and bunch shaping they need to be carefully investigated during the commissioning. In this proceeding we will discuss a measurement technique that will be used during commissioning to characterize the longitudinal wakefields and their precise effects on e.g. the bunch shape and the energy spread. Predictions obtained from particle tracking will be presented.

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THPRO077

The New FREIA Laboratory for Accelerator Development

cryomodule, controls, FEL, cryogenics

3059

R.J.M.Y. Ruber, A.K. Bhattacharyya, T.J.C. Ekelöf, K. Fransson, K.J. Gajewski, V.A. Goryashko, L. Hermansson, M. Jacewicz, T. Lofnes, M. Olvegård, R. Santiago Kern, R. Wedberg, R.A. Yogi, V.G. Ziemann
Uppsala University, Uppsala, Sweden
D.S. Dancila, A. Rydberg
Uppsala University, Department of Engineering Sciences, Uppsala, Sweden

The FREIA laboratory is a Facility for REsearch Instrumentation and Accelerator Development at Uppsala University, Sweden constructed recently to develop and test accelerator components. Initially it will develop the RF system for the spoke cavities of the ESS linac and test prototype spoke cavities at nominal RF power. For this purpose we installed a helium liquefaction plant, a versatile horizontal test cryostat and two 352 MHz RF power stations, one based on two tetrodes and the other on solid state technology. Beyond these developments FREIA will house a neutron generator and plans for a THz FEL are under discussion. FREIA is embedded in the Ångström physics, chemistry and engineering campus at Uppsala in close proximity to mechanical workshops, clean room with electron microscopes, tandem accelerator and the biomedical center.

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THPRO099

Toward a Virtual Accelerator Control System for the MYRRHA Linac

controls, operation, lattice, cryomodule

3122

J.-P. Carneiro
Fermilab, Batavia, Illinois, USA
J.-L. Biarrotte
IPN, Orsay, France
F. Bouly
LPSC, Grenoble Cedex, France
L. Medeiros Romão, R. Salemme, D. Vandeplassche
SCK•CEN, Mol, Belgium
D. Uriot
CEA/DSM/IRFU, France

The MYRRHA project currently under development at Mol, Belgium, is an Accelerator Driven System expected to be operational in 2023 with the primary purpose to study the feasibility of efficiently transmuting nuclear waste products into isotopes with much shorter lifetimes. The reactor, which is expected to have a thermal power of ~70 MW, may be operated in subcritical mode when fed by spallation neutrons obtained from a 600 MeV superconducting proton linac hitting a Liquid Pb-Bi eutectic (LBE) target with an average current of 4 mA. The challenging aspect of the MYRRHA linac resides in its very high availability (close to 100%) with a Mean Time Between Failure expected to be higher than 250 hours. This paper presents the strategic approach taken during the design of the linac and its foreseen operation to fulfill this stringent requirement. In particular we will describe the concept of a beam dynamics based control system also called Virtual Accelerator which will be mandatory for the operation of such linac.

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THPRO109

Design and Status of the SuperKEKB Accelerator Control Network System

network, controls, EPICS, Ethernet

3150

M. Iwasaki, K. Furukawa, T.T. Nakamura, T. Obina, S. Sasaki, M. Satoh
KEK, Ibaraki, Japan
T. Aoyama, T. Nakamura
Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan

We have upgraded the accelerator control network system for SuperKEKB, the upgrade of the KEKB asymmetric energy e⁺e⁻ collider for the next generation B-factory experiment in Japan. For SuperKEKB, the accelerator control network system with the higher performance of the wider bandwidth data transfer, and more reliable and redundant configuration, is required, to ensure the robust operations under the 40 times higher luminosity. We install the 10 gigabit Ethernet (10GbE) network switches for the wider network bandwidth and optical cables to construct the redundant network. We reconfigure the network design to connect the accelerator control network and the KEK laboratory network to enhance the security. For the beamline construction and the accelerator components maintenance, we install the new wireless network system consists with the Leaky Coaxial (LCX) cable antennas and collinear antennas, which have good radiation hardness of >1MGy, into the 3 km circumference accelerator tunnel. In this paper, we describe the design and current status of the SuperKEKB accelerator control network system.

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THPRO111

Control System for BEPCII Linac Power Sub-system

controls, power-supply, EPICS, operation

3156

X. Wu, X.C. Kong, Q. Le, S. Sun, Y. Zou
IHEP, Beijing, People's Republic of China

Power subsystem has been upgraded for energy improvement of the BEPCII Linac. As a result, new control system was in need. This paper proposes the designing and implementation about the power-supply control system. There are 156 sets of power supply in the system, which is divided into 6 parts, according to function. The control system is intended to make operations more convenient and efficient in beam regulation, which provides functions to meet such situations, like single regulation; restore the beam configures from data files; one-button to switch the electronic polarity (E-/E+). What’s more, the software provides a method of slow-change to protect the power supplies, when value change is too steep. Compare to the old system, this new software is more maintainable and extensible. This software is based on Qt, the GUI library for C++, and connects to the control box through the EPICS (Experimental Physics and Industrial Control System). The whole 156 sets of power supply are controlled by control boxes, which is ARM+FPGA (CPLD)-Structure front-end IO. This control system has assembled in BEPCII LINAC in September, which plays an important part in the following working.

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THPRO129

Online Modeling of the Rare Isotope Reaccelerator - ReA3

emittance, rfq, SRF, diagnostics

3195

W. Wittmer, D.M. Alt, S.W. Krause, D. Leitner, S. Nash, R. Rencsok, J.A. Rodriguez, M.J. Syphers, X. Wu
NSCL, East Lansing, Michigan, USA

Funding: Work supported by Michigan State University
With the installation and commissioning of the third accelerating cryomodule in summer of 2014 the first phase of the radioactive ion beams postaccelerator ReA at National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) will be completed. ReA was integrated in 2013 into the Coupled Cyclotron Facility providing unique low-energy rare isotope beams. After the fast rare isotopes are stopped in a gas stopping system, mass separated and their charge state boosted in an Electron Beam Ion Trap (EBIT), the ions are reaccelerated in a compact superconducting (SC) LINAC. For rare isotope operations, the LINAC is pre-tuned using stable pilot beams with a similar mass to charge ratio as the rare isotope beams and consequently the system is scaled. Scaling steps of up to 5\% are needed to change to the radioactive beams. To preserve the stringent beam characteristic on the experimental end station a precise online model is required. We will present the status of this online model.

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THPME002

Delta-Phi Method for the IFMIF-LIPAc SRF-Linac Cavity Tuning

cavity, simulation, SRF, focusing

3205

M. Valette, N. Chauvin
CEA/IRFU, Gif-sur-Yvette, France
P.A.P. Nghiem, D. Uriot
CEA/DSM/IRFU, France

In order to achieve the upcoming commissioning of the IFMIF-LIPAc prototype accelerator in Rokkasho, the precision and resolution required for all diagnostics must be determined. These specifications will depend on the precision at which the tuning parameters must be set and finally by the tuning errors that can be tolerated on the beam itself. We will here discuss the use of the ∆φ method to tune the SRF-Linac and the resolution requirements it implies for the BPMs. This method, using a relative time of flight measurement to assess the energy of the beam, has the advantages of allowing setting the beam energy and beam longitudinal focusing at once.

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THPME003

A Precise Determination of the Core-halo Limit

emittance, space-charge, extraction, instrumentation

3208

P.A.P. Nghiem, N. Chauvin, D. Uriot, M. Valette
CEA/DSM/IRFU, France
W. Simeoni
IF-UFRGS, Porto Alegre, Brazil

For high-intensity beams, the dynamics of the dense core is different from that of the much less dense halo. Relations between core emittance growth and halo generation are often studied, halo scraping often experienced and halo re-formation observed. For all that, a clear distinction between the core and the halo parts does not exist. This paper proposes a new method for precisely determining the core-halo limit applicable to any particle distribution type. Once this limit is known, the importance of the halo relative to the core can be precisely quantified. The core-halo limit determination may be easily extended to the nD phase space, allowing the definition of emittance and Twiss parameters for the core and the halo separately.

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THPME004

Further R&D for a New Superconducting CW Heavy Ion Linac@GSI

cavity, ion, solenoid, heavy-ion

3211

W.A. Barth, S. Mickat
GSI, Darmstadt, Germany
M. Amberg, K. Aulenbacher, V. Gettmann
HIM, Mainz, Germany
F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany

A low energy beam line (1.4 MeV/u) behind the GSI High Charge State Injecor will provide cw-heavy ion beams with high beam intensity. It is foreseen to build a new cw-heavy ion-linac for post acceleration up to 7.3 MeV/u. In preparation an advanced R&D program is defined: The first linac section (financed by HIM and partly by HGF-ARD-initiative) comprising a sc CH-cavity embedded by two sc solenoids will be tested in 2014/15 as a demonstrator. After successful testing the construction of an advanced cryomodule comprising four rf cavities is foreseen. As an intermediate step towards an entire cw-linac the use of a double of two CH-cavities is planned: Ashort 5 cell cavity should be mounted directly behind the demonstrator cavity inside a short cryostat. The design of the cw linac based on shorter sc CH-cavities would minimize the overall technical risk and costs. Besides with this cavity an optimized operation of the whole linac especially with respect to beam quality could be achieved. Last but not least the concept of continuous energy variation applying phase variation between the two cavities with constant beta profile could be tested.

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THPME005

Optimization of an IH-cavity based High Energy Heavy-ion Linac at GSI

emittance, cavity, ion, brilliance

3214

A. Orzhekhovskaya, G. Clemente, L. Groening, S. Mickat, B. Schlitt
GSI, Darmstadt, Germany

A new high energy heavy-ion injector (HE-Linac) for the FAIR project was proposed as replacement for the existing post-stripper linac at the GSI UNILAC. Six 10⁸ MHz IH-type drift-tube linac cavities within a total length of about 24 m accelerate the ions (up to U²⁸⁺) from 1.4 MeV/u up to 11.4 MeV/u. Fast pulsed quadrupole triplet lenses are used for transverse focusing in between the IH cavities. The optimization of the HE linac with respect to the emittance growth reduction is investigated.

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THPME009

Beam Dynamics for the FAIR Proton-Linac RFQ

rfq, bunching, simulation, focusing

3226

C. Zhang
GSI, Darmstadt, Germany

The FAIR (Facility for Antiproton and Ion Research) Proton-Linac (P-LINAC) will be started with a 325.224 MHz, 3 MeV Radio-Frequency Quadrupole (RFQ) accelerator. To ensure that a ≥35 mA beam can be injected into the downstream synchrotrons, the design beam intensity of this Proton-RFQ (P-RFQ) has been chosen as 70 mA. Based on the so-called NFSP (New Four-Section Procedure) method, two new beam dynamics designs with varying and constant transverse focusing strength, respectively, have been worked out to meet the latest design requirements using a compact structure. This paper presents the main design concepts and simulation results.

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THPME010

A 325 MHz High Gradient CH – Test Cavity for β=0.16

cavity, operation, focusing, DTL

3229

A. Almomani, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: BMBF, contract no. 05P12RFRB9
This pulsed linac activity aims on compact designs, which means a considerable increase in voltage gain per meter. At IAP – Frankfurt, a CH – cavity was developed for these studies, where mean effective accelerating fields well above 10 MV/m are expected at 325 MHz, β=0.164. This cavity is developed within a funded project. Currently, the cavity is under construction and expected to be ready for copper plating in autumn 2014. The results might influence the rebuilt of the UNILAC – Alvarez section, which aims on achieving the beam intensities specified for the GSI – FAIR project. The new GSI 3 MW Thales klystron test stand will be very important for these investigations. Detailed investigations for two different types of copper plating can be performed on this cavity. In this work, the status of the cavity fabrication will be presented. Moreover, low temperature operation of copper cavities is discussed for the case of very short RF pulses.

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THPME011

First Coupled CH Power Cavity for the FAIR Proton Injector

cavity, proton, coupling, alignment

3232

R. M. Brodhage, G. Clemente, W. Vinzenz
GSI, Darmstadt, Germany
R. M. Brodhage, U. Ratzinger
IAP, Frankfurt am Main, Germany

For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. In 2013 the final drift tube structure has been welded inside the main tanks and the preparation for copper plating has taken place. This paper will report on the main tuning and commissioning steps towards that novel type of DTL and it will show the latest results measured on a fully operational CH proton cavity shortly before copper plating.

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THPME012

Results of the High Power Test of the 325 MHz 4-Rod RFQ Prototype

rfq, impedance, proton, dipole

3235

B. Koubek, H. Podlech, A. Schempp, J.S. Schmidt
IAP, Frankfurt am Main, Germany

For the FAIR proton linac at GSI a 325 MHz 4-rod RFQ prototype has been built. On this prototype RF measure- ments have been carried out. After low power conditioning in cw mode the structure was high power tested in pulsed mode. During the performance tests the 6 stem prototype was optimized and has shown the feasibility of a dipole free 4-rod RFQ at high frequencies and was testet up to 120 kW per meter. In this tests the input power and the electrode voltage was observed using gamma spectroskopy. From this the shunt impedance was calculated and compared to other methods of measurements. The power test results are presented in this paper.

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THPME017

Electromechanical Analysis of SCDTL Structures

cavity, coupling, proton, feedback

3250

M. Ciambrella, F. Cardelli, M. Migliorati, A. Mostacci, L. Palumbo
URLS, Rome, Italy
L. Ficcadenti, V. Pettinacci
INFN-Roma, Roma, Italy
L. Picardi, C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

The Side Coupled Drift Tube Linac (SCDTL) is a 3 GHz accelerating structure for proton therapy linac designed for TOP-IMPLART, an Intensity Modulated Proton Linear Accelerator for Radio-Therapy. The structure is made up of short DTL accelerating tanks for low current proton beams, coupled by side coupling cavities. The purpose of this paper is to report on the analysis of electromagnetic and the thermo-mechanical behavior for the SCDTL structure. The 3D electromagnetic analysis is used to derive the power dissipation on the structure; then one can infer the temperature distribution and deformation field in order to eventually evaluate their feedback on the electromagnetic properties of the structure as, for instance, the cavity resonant frequency shift. Such a "multi-physics'' analysis has been performed for different supporting stem geometries in order to optimize the shunt impedance and the R/Q for SCDTL cavities.

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THPME018

Global Search Methods for Electromagnetic Optimization of Compact Linac Tanks

coupling, proton, cavity, HOM

3253

O. Losito, V. Dimiccoli, G. Rutigliani
ITEL, Ruvo di Puglia, Italy
L. De Palma, F. Prudenzano
Politecnico di Bari (DEI), Bari, Italy

We shows the optimization of a five cell tank to be included as first multi-cavity within a LINAC section accelerating a proton beam from 7 MeV to higher energies, useful for proton therapy. The tank performance depends on a set of physical (beam characteristics) and geometrical parameters (radius and lengths of accelerating and coupling cavities, radius and thickness of the coupling holes among accelerating cells, the radius and the thickness of the coupling holes between off-axis coupling cells and accelerating ones). PSO (Particle Swarm Optimization) and ACO (Ant Colony Optimization) have been used as approaches for the electromagnetic optimization. The model used for the fitness calculation takes into account all the most important effects occurring in the tank coupled cavities loaded by the proton beam. The codes based on PSO and ACO have enabled the global and stochastic identification of about ten optimized parameters. The design goodness has been tested via Particle and Microwave CST Studio © simulation. The optimized tank accelerates the proton beam input energy from Ein=7 MeV to about Eout= 8.2 MeV. These values, well agree with other designs reported in literature.

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THPME019

LIPAc, the 125mA / 9MeV / CW Deuteron IFMIF’s Prototype Accelerator: What Lessons Have We Learnt from LEDA?

rfq, proton, emittance, space-charge

3256

F. Scantamburlo, J. Knaster, Y. Okumura
IFMIF/EVEDA, Rokkasho, Japan
N. Chauvin, R. Gobin, P.A.P. Nghiem
CEA/DSM/IRFU, France
A. Kasughai, H. Shidara
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan

The Engineering Validation and Engineering Design Activities (EVEDA) phase of IFMIF aims at running a 9 MeV / 125 mA / CW deuteron accelerator to demonstrate the feasibility of IFMIF’s 40 MeV / 125 mA / CW accelerator with components mainly designed and constructed in European labs. LEDA was operated successfully in 1999-2001 as a 6.7 MeV / 100 mA / CW proton accelerator with high availability. The present paper assesses the experience gained in LEDA and explains how LIPAc, the IFMIF prototype accelerator, is inheriting its role of breaking through technological boundaries.

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THPME020

Local Compensation-rematch for the C-ADS Accelerator Element Failures with Space Charge

solenoid, emittance, cavity, focusing

3259

B. Sun, C. Meng, J.Y. Tang, F. Yan
IHEP, Beijing, People's Republic of China

In order to achieve the required reliability and availability for the C-ADS accelerator, a fault tolerance design is pursued. The effects of cavity and solenoid failure in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one cavity failure, by adjusting the settings of the neighbouring cavities and the focusing elements we can make sure that the Twiss parameters and energy are approximately recovered to that of the nominal ones at the matching point. However, the compensation work above is based on the TraceWin code, which has not considered the phase compensation, a code based on MATLAB is under developing to compensate the arrival time at the matching point that the linear space charge effect has also considered.

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THPME021

Designs of High-intensity Proton Linacs with Non-equipartitioning

emittance, cavity, proton, accelerating-gradient

3262

C. Meng, Z. Li, S. Pei, B. Sun, J.Y. Tang, F. Yan
IHEP, Beijing, People's Republic of China
R. Garoby, F. Gerigk, A.M. Lombardi
CERN, Geneva, Switzerland

Superconducting technology is playing more and more important roles in high-power proton linacs. Periodic phase advance less than 90 degrees and equipartitioning design are considered very important principles in linac design. Due to the very high construction and operation costs, it is very important in optimizing the design to lower the costs. In usual, the longitudinal emittance is larger from the front-end, thus the transverse phase advance is designed to have a larger value. However, with the technical advancement, higher accelerating field can be obtained. In order to take this advantage, it is of much interest in increasing the longitudinal phase advance to shorten the linac or reduce the cost. In this paper, we present the design method that keeping the longitudinal phase advance as large as possible but smaller than 90 degree to maximize the use of the available accelerating gradient. Even though this method does not observe the equipartitioning condition, we can also obtain very good beam dynamics results by placing the tunes in resonant-free regions. In this paper, the design and simulation results by applying this method to the SPL and China-ADS linac will be present.

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THPME022

Recent Progress of the SSC-LINAC RFQ

rfq, cavity, operation, pick-up

3265

G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
PKU, Beijing, People's Republic of China
H. Du, Y. He, P. Jiang, X.N. Li, Z.S. Li, J.X. Wu, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, X.H. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: NFSC(11079001)
The project of SSC-LINAC RFQ has important progresses in the past year. The machine has been moved to the Institute of Modern Physics in the first season of 2013. The cavity measurement including tests of RF performance and field distribution is carried out again in the laboratory. The Q0 is 6440, and the unflatness of the electric field in longitudinal is ±2.5%. The results demonstrated a good agreement with simulation. The RF and beam commissioning of the RFQ has been carried out in the first half of 2014. The duty factor rose from 5% to CW gradually. By now, the cavity has been operated with 35 kW on CW mode. The measurement of the bremsstrahlung spectrum reveals that the 35 kW power is needed to generate the 70 kV inter-vane voltage. The beam transmission efficiency and energy spread has been obtained in beam commissioning by accelerating 16O⁵⁺ and 40Ar⁸⁺ beams. The efficiency of 40Ar⁸⁺ is as high as 94%, and the output energy is 142.78 keV/u. All the processes and results of the experiments will be discussed in details.

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THPME023

CPHS Linac Status at Tsinghua University

rfq, target, neutron, operation

3268

Q.Z. Xing, C. Cheng, L. Du, T. Du, X. Guan, C. Jiang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and 11175096).
We present, in this paper, the operation status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The pulse length will be further increased to 500 μs. The proton beam energy is expected to be enhanced to the designed value of 13 MeV after the Drift Tube Linac is ready in 2015.

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THPME024

Cooling Design for the FRIB RFQ Cavity at Michigan State University

rfq, simulation, cavity, operation

3271

J. Zeng, L. Du, X. Guan, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, J. Li
NUCTECH, Beijing, People's Republic of China

Funding: Work supported by the Major Research plan of the National Natural Science Foundation of China (Grant No. 91126003)
We present, in this paper, the cooling design for the Radio Frequency Quadrupole (RFQ) cavity of the Facility for Rare Isotope Beams (FRIB) at Michigan State University. The locations and radius of the cooling passages are optimized, which exist in the five-meter-long copper cavity, tuners, dipole-mode stabilizing rods and end-plates. A three-dimensional RF, thermal, and structural analysis by ANSYS has been performed to carry out the design and verify that the present design can meet the requirement for water velocity, stress, deformation and frequency shift.

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THPME025

Low Power Test of a Hybrid Single Cavity Linac

rfq, cavity, ion, injection

3274

L. Lu, Y. He, Q. Jin, C.X. Li, G. Pan, A. Shi, L.B. Shi, L.T. Sun, L.P. Sun, Z.L. Zhang, H.W. Zhao, H. Zhao
IMP, Lanzhou, People's Republic of China
T. Hattori
NIRS, Chiba-shi, Japan
N. Hayashizaki
RLNR, Tokyo, Japan

We fabricated and assembled a hybrid single cavity (HSC) linac which is formed by combining a radio frequency quadrupole (RFQ) structure and a drift tube (DT) structure into one interdigital-H (IH) cavity. ]. The HSC linac was designed as an injector for a cancer facility and was able to be used as a neutron source for boron neutron capture therapy. The injection method of the HSC linac used a direct plasma injection scheme (DPIS), which is considered to be the only method for accelerating a high current heavy ion beam produced by a laser ion source. The input beam current was designed to be 20 mA, which could be produced by a laser ion source. According to the simulations and calculations, the HSC linac could accelerate a 6-mA C⁶⁺, beam which satisfies the particle number criteria for cancer therapy use (10⁸~9 ions/pulse). Details of the measurements and evaluations of the assembled HSC linac, and details of a DPIS test using a laser ion source are reported in this paper.

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THPME026

The R&D Status of SSC-LINAC

rfq, ion, ion-source, ECR

3277

X. Yin, H. Du, Y. He, P. Jiang, X.N. Li, L.Z. Ma, J. Meng, L.T. Sun, H. Wang, J.W. Xia, Z. Xu, Y.Q. Yang, Q.G. Yao, Y.J. Yuan, X.H. Zhang, X.Z. Zhang, H.W. Zhao, Z.Z. Zhou
IMP, Lanzhou, People's Republic of China
J.E. Chen, S.L. Gao, G. Liu, Y.R. Lu, X.Q. Yan, K. Zhu
PKU, Beijing, People's Republic of China

A powerful heavy ion injector SSC-linac is under constructing at IMP in Lanzhou. The continuous wave (CW) 4-rod RFQ operating at 53.667 MHz has been developed as the low beam energy injector linac. The 40Ar⁸⁺ ion beam extracted from the ECR ion source was used for the RFQ commissioning. The particle energy 142.8 keV/u and the 198 euA beam current were measured at the exit of RFQ with the 94% transmission. In this paper, the recent R&D progress of the SSC-LINAC including the development of key components and the beam commissioning results are presented.

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THPME027

Development of the injector II RFQ for China ADS project

rfq, cavity, acceleration, proton

3280

Z.L. Zhang, Y.H. Guo, Y. He, H. Jia, C.X. Li, Y. Liu, L. Lu, G. Pan, A. Shi, L.B. Shi, L.P. Sun, W.B. Wang, X.W. Wang, J.X. Wu, Q. Wu, X.B. Xu, B. Zhang, J.H. Zhang, H.W. Zhao, T.M. Zhu
IMP, Lanzhou, People's Republic of China
M.D. Hoff, A.R. Lambert, D. Li, J.W. Staples, S.P. Virostek
LBNL, Berkeley, California, USA
C. Zhang
GSI, Darmstadt, Germany

As one of the main components of the injector II of China ADS LINAC project, an RFQ working at 162.5MHz is used to accelerate proton beams of 15mA from 30 keV to 2.1 MeV. The four vane RFQ has been designed in collaboration with Lawrence Berkeley National Laboratory and built at the workshop of the Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS). Low power test of the cavity have been completed, and it shows the field flatness is within ±1% and the unloaded Q is 12600. RF conditioning has been completed, results of preliminary beam test show the output beam energy is 2.16 MeV with energy spread of 3.5% and the transmission efficiency is 97.9%. Continuous wave (CW) beam of 2.3 mA has been accelerated for more than one hour.

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THPME030

Beam Dynamics and Accelerating Cavity Electrodynamics' Simulation of CW 2 MeV Proton RFQ

rfq, cavity, simulation, Windows

3286

S.M. Polozov, A.E. Aksentyev, T. Kulevoy
MEPhI, Moscow, Russia

The CW proton linac has a number of important applications; serving as the initial part of a high-energy, high-power linac for an accelerator-driven system is the main of them. Its CW operation mode and a 5-10 mA beam current, however, are limiting factors for the accelerating field. The surface field should not exceed the Kilpatrick field by more than 1.2-1.5 times. This limitation leads to the increase in linac length and beam bunching complexity. The first results of a 2 MeV, 5 mA, CW RFQ, designed for the operating frequency of 162 MHz, are discussed. Beam dynamics simulation results, obtained by using the BEAMDULAC-RFQ code*, are presented. The electrodynamics of the accelerating structure based on the four-vane cavity is discussed. The accelerating cavity design uses coupling windows as was proposed earlier **, but with windows of an elliptical form. Such form allows for better separation of quarupole and dipole modes.
* S.M. Polozov. Problems of Atomic Science and Technology. Series: Nuclear Physics Investigations, 3 (79), 2012, p. 131-136.
** V.A. Andreev. Patent US5483130, 1996.

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THPME031

Beam Dynamics Simulation in SC Linac for the Proton Radiotherapy

simulation, proton, cavity, focusing

3289

S.M. Polozov, I.A. Ashanin, A.V. Samoshin
MEPhI, Moscow, Russia

Superconducting linear accelerators based on short independently phased SC cavities are widely used today in ADS and FRIB. Such accelerator can be useful as proton therapy beam source*. The accelerator general layout to accelerate proton beam at the energy range 2-240 MeV will detail in this report. Obviously, in this linac will always violate the principle of synchronicity when the synchronous particle velocity is equal to the phase velocity of the accelerating wave and a slipping of particles relative to the accelerating wave. The beam dynamics simulation shows that linac should consist of four groups of identical cavities. Cavities should have phase velocities as βg=0.1, 0.18, 0.3 and 0.49 respectively. The choice of optimum parameters of accelerating cavities and focusing magnets will discussed and the beam dynamics simulation results will presented.
*S.M. Polozov, A.V. Samoshin. Proc. of LINAC’12, pp. 633-635

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THPME032

Beam Transfer Studies for LINCE Experimental Areas

optics, beam-transport, quadrupole, acceleration

3292

L. Acosta, C. Bonțoiu, I. Martel, A.R. Pinto Gómez, A.C.C. Villari
University of Huelva, Huelva, Spain
J. Lucas
Elytt Energy, Madrid, Spain
A.C.C. Villari
FRIB, East Lansing, Michigan, USA

Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
Beam transport from the exit of the LINCE linac to experimental areas has been optimized for a few ion species using transfer matrix calculations performed in MADX. An alpha spectrometer based on a double-bending achromat lattice has been used as dispersion suppressor and particle tracking studies have been carried out in GPT along it and the three beamlines. Realistic quadrupole and dipole magnet design achieved in Comsol enabled accurate particle tracking studies and evaluation of the beam parameters delivered at the target.

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THPME033

Particle Tracking Studies for the LINCE SC Linac

cryomodule, solenoid, ion, lattice

3295

C. Bonțoiu, I. Martel
University of Huelva, Huelva, Spain
A. Falone
TTI, Santander, Spain
C. Gómez
IDOM, Bilbao, Spain

Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
LINCE facility makes use of a low-energy ion linac consisting of quarter-wave resonators designed for β = 0.045, 0.077 and 0.15 (72.75 and 10⁹.125 MHz), and shielded solenoid magnets distributed along four different cryomodules. Particle tracking studies have been performed along the linac using realistic electric and magnetic field maps with and without space charge effects to prove a final energy of 8.5 and 45 MeV/u respectively for uranium ions and protons.

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THPME036

ECOS-LINCE: A High Intensity Multi-ion Superconducting Linac for Nuclear Structure and Reactions

ion, heavy-ion, ECR, rfq

3301

I. Martel, L. Acosta, R. Carrasco Dominguez, J.A. Dueñas, A.K. Orduz, A. Peregrin, J. Prieto-Thomas, J. Sanchez-Segovia, A.C.C. Villari
University of Huelva, Huelva, Spain
F. Azaiez
IPN, Orsay, France
G. De Angelis
INFN/LNL, Legnaro (PD), Italy
M. Lewitowicz
GANIL, Caen, France
A. Maj
IFJ-PAN, Kraków, Poland
P.N. Ostroumov
ANL, Argonne, Illinois, USA
A.C.C. Villari
FRIB, East Lansing, Michigan, USA

Funding: Work partially supported by the Spanish Government (MINECO-CDTI) under program FEDER INTERCONNECTA.
During the past ten years, ECOS working group and users strongly supported the construction of a dedicated high-intensity stable-ion-beam facility in Europe, with energies at and above the Coulomb barrier as part of the Long-Range Plan of the Nuclear-Physics community. LINCE will be a multi-user facility dedicated to ECOS science: fundamental physics, astrophysics, nuclear structure and reaction dynamics. Applied research is foreseen in the fields of medical physics, aerospace and material sciences with energetic heavy ions. The facility will produce a wide range of ions, from protons (45 MeV) up to Uranium (8.5 MeV/u) with 1mA maximum beam intensity. A very compact linac has been designed by using a HV platform with a double-frequency ECR ion source, multi-harmonic buncher, an innovative CW RFQ design (1 ≤A/Q ≤ 7) and 26 accelerating cavities made of bulk niobium (β = 0.045, 0.077 and 0.15) working at 72.75 and 10⁹.125 MHz. This article gives an outline of the accelerator complex from the ion source to the experimental areas, and presents its research potential and the relevant physics instrumentation.

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THPME039

Requirements for ESS Superconducting Radio Frequency Linac

cryomodule, SRF, cavity, cryogenics

3311

C. Darve, M. Eshraqi, D.P. McGinnis, S. Molloy, E. Tanke
ESS, Lund, Sweden

The European Spallation Source (ESS) is a pan-European project. It will be built by at least 17 European countries, with Sweden and Denmark as host nations. The Superconducting Radio-Frequency (SRF) linac is composed of one section of spoke cavity cryomodules (352.21 MHz) and two sections of elliptical cavity cryomodules (704.42 MHz). These cryomodules contain niobium SRF cavities operating at 2 K. Following a redesign of its accelerator, SRF linac design shall comply with a new set of requirement, like an increase of the beam current from 50 mA to 62.5 mA and an increase of the peak electrical surface field from 40 MV/m to 45 MV/m. Requirements and the main disciplines needed to construct this portion of the linac are presented.

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THPME041

ESS DTL Status: Redesign and Optimizations

DTL, emittance, quadrupole, focusing

3314

R. De Prisco, M. Eshraqi
ESS, Lund, Sweden
M. Comunian, F. Grespan, A. Pisent
INFN/LNL, Legnaro (PD), Italy
A.R. Karlsson
Lund University, Lund, Sweden

The European Spallation Source (ESS) uses a linear accelerator to deliver the high intensity proton beam to the target station. The average beam power is 5 MW with a peak beam power at target of 125 MW. In 2013 the ESS linac was costed and to meet the budget some modifications were introduced: the final energy was decreased from 2.5 GeV to 2.0 GeV and the beam current was increased from 50 mA to 62.5 mA to keep the same beam power. As a consequence the ESS Drift Tube Linac, DTL, has been re-designed to match the new requirements. This paper presents the main Radio Frequency (RF) and beam dynamics choices for the ESS DTL.

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THPME042

Preliminary Functional Analysis and Operating Modes of ESS 704 MHz Superconducting Radio-Frequency Linac

cryomodule, controls, EPICS, SRF

3317

N. Elias, C. Darve, J. Fydrych, A. Nordt, D.P. Piso
ESS, Lund, Sweden

The European Spallation Source (ESS) is one of Europe’s largest planned research infrastructures. The project is funded by a collaboration of 17 European countries and is under design and construction in Lund, Sweden. Three families of Superconducting Radio-Frequency (SRF) cavities are being prototyped, counting the spoke resonators with a geometric beta of 0.5, medium-beta elliptical cavities (β=0.67) and high beta elliptical cavities (β=0.86). The ESS linac will produce 2.86 ms long proton pulses with a repetition rate of 14 Hz (4 % duty cycle), a beam current of 62.5 mA and an average beam power of 5 MW. A control system is being developed to operate the different accelerator systems. All operating modes of the superconducting linac shall ensure a safe operation of the accelerator. This paper presents the preliminary functional analysis and the operating modes of the 704 MHz SRF linac.

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THPME043

The ESS Linac

target, rfq, proton, quadrupole

3320

M. Eshraqi, H. Danared, R. De Prisco, M. Lindroos, D.P. McGinnis, R. Miyamoto, M. Muñoz, A. Ponton, E. Sargsyan
ESS, Lund, Sweden
I. Bustinduy
ESS Bilbao, Bilbao, Spain
L. Celona
INFN/LNS, Catania, Italy
M. Comunian, F. Grespan
INFN/LNL, Legnaro (PD), Italy
S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark

The European Spallation Source, ESS, uses a linear accelerator to bombard the tungsten target with the high intensity protons beam for producing intense beams of neutrons. The nominal average beam power of the linac is 5~MW with a peak beam power at target of 125~MW. During last year the ESS linac was costed, and to meet the budget a few modifications were introduced to the linac design. One of the major changes is the reduction of final energy from 2.5~GeV to 2.0~GeV and therefore beam current was increased accordingly to compensate for the lower final energy. As a result the linac is designed to meet the cost objective by taking a higher risk. This paper focuses on the driving forces behind the new design, engineering and beam dynamics requirements of the design and finally on the beam dynamics performance of the linac.

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THPME044

Statistical Error Studies in the ESS Linac

rfq, emittance, alignment, DTL

3323

M. Eshraqi, R. De Prisco, R. Miyamoto, E. Sargsyan
ESS, Lund, Sweden
H.D. Thomsen
ISA, Aarhus, Denmark

Following the completion of the latest layout of the ESS linac statistical error studies have been performed to define the field vector quality and alignment tolerances. Based on these tolerances and error study results a scheme for the correction system is proposed that assures low losses and permits hands-on maintenance. This paper reports on the strategy of simulating and performing the error studies as well as setting the tolerances.

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THPME045

Beam Physics Design of the ESS Medium Energy Beam Transport

DTL, rfq, lattice, emittance

3326

R. Miyamoto, B. Cheymol, M. Eshraqi
ESS, Lund, Sweden
I. Bustinduy
ESS Bilbao, Bilbao, Spain

A radio frequency quadrupole (RFQ) and drift tube linac (DTL) in the ESS proton linac are connected with a medium energy beam transport (MEBT) to remove low intensity bunches on the head and tail of a macro-pulse with a chopper and house diagnostic devices to characterize and adjust the beam out of the RFQ for the DTL. These must be achieved within a relatively short space and without large degradation of beam quality due to space charge force, imposing a challenge on the lattice design. This paper presents a beam physics design of the MEBT in the ESS proton linac, which satisfies its requirement while preserving a decent beam quality.

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THPME047

Sorting in the ESS

cavity, beam-losses, emittance, simulation

3329

S. Peggs, E. Laface, E. Sargsyan, R. Zeng
ESS, Lund, Sweden

Sorting optical elements has significant potential during the construction of superconducting linacs like the ESS, in the same way that it has proved to be very effective in circular accelerators like RHIC and the LHC. In the linac domain, the elements of primary interest are cavities and cryomodules, instead of the magnets (of all sorts) that are routinely sorted in circular accelerators. Multiple cavities can be sorted to optimise individual cryomodules, and cryomodules can be sorted into optimised locations within the tunnel. Different sorting strategies are discussed and preliminarily evaluated in this paper. Central to the evaluation is the identification of goal (or penalty) functions that are maximised (or minimised), and which can be rapidly quantified by simulation. Also crucial is the availability of a modeling system that is realistic in its complex representation of the linac, and which can easily be modified and developed.

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THPME048

Status and Plans for Linac4 Installation and Commissioning

ion, rfq, ion-source, emittance

3332

M. Vretenar, A. Akroh, L. Arnaudon, P. Baudrenghien, G. Bellodi, J.C. Broere, O. Brunner, J.F. Comblin, J. Coupard, V.A. Dimov, J.-F. Fuchs, A. Funken, F. Gerigk, E. Granemann Souza, K. Hanke, J. Hansen, I. Kozsar, J.-B. Lallement, L. Lenardon, J. Lettry, A.M. Lombardi, C. Maglioni, O. Midttun, B. Mikulec, D. Nisbet, M.M. Paoluzzi, U. Raich, S. Ramberger, F. Roncarolo, C. Rossi, J.L. Sanchez Alvarez, R. Scrivens, J. Tan, C.A. Valerio, J. Vollaire, R. Wegner, S. Weisz, M. Yarmohammadi Satri, F. Zocca
CERN, Geneva, Switzerland

Linac4 is a normal conducting 160 MeV H⁻ linear accelerator presently being installed and progressively commissioned at CERN. It will replace the ageing 50 MeV Linac2 as injector of the PS Booster (PSB), increasing at the same time its brightness by a factor of two thanks to the higher injection energy. This will be the first step of a program to increase the beam intensity in the LHC injectors for the needs of the High-Luminosity LHC project. After a series of beam measurements on a dedicated test stand the 3 MeV Linac4 front-end, including ion source, RFQ and a beam chopping line, has been recommissioned at its final position in the Linac4 tunnel. Commissioning of the following section, the Drift Tube Linac, is starting. Beam commissioning will take place in steps of increasing energy, to reach the final 160 MeV in 2015. An extended beam measurement phase including testing of stripping equipment for the PSB and a year-long test run to assess and improve Linac4 reliability will take place in 2016, prior to the connection of Linac4 to the PSB that will take place during the next long LHC shut-down.

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THPME049

TAC Proton Accelerator Facility: Normal Conducting Part

proton, ion-source, ion, DTL

3335

E. Algin
Eskisehir Osmangazi University, Eskisehir, Turkey
B. Akkus, L. Sahin
Istanbul University, Istanbul, Turkey
H. Cetinkaya
Dumlupinar University, Faculty of Science and Arts, Kutahya, Turkey

The Turkish Accelerator Center Proton Accelerator Facility (TAC PAF) based on a 1 MW, 2 GeV proton linac will include both normal conducting and superconducting accelerator structures. The project is currently in the technical design phase. The normal conducting part of the TAC PAF will consist of an ion source, a low energy beam transport line, a radio frequency quadrupole, a medium energy beam transport line, and two drift tube linac structures in order to accelerate the beam up to 65 MeV. Acceleration from 65 MeV up to 150 MeV and then 2 GeV energy will be provided by a SC-spoke cavity and two SC-elliptical cavities, respectively. In the long term, TAC PAF will be used as a neutron source. The accelerator structures, their design, and possible experimental stations of TAC PAF project will be presented.

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THPME051

Preparatory Investigations for a Low Frequency Prebuncher at ReA

rfq, bunching, simulation, detector

3342

D.M. Alt, J.F. Brandon, D. Leitner, D. Morris, M.J. Syphers, N.R. Usher, W. Wittmer
NSCL, East Lansing, Michigan, USA

The ReA reaccelerator facility at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) will provide a unique capability to study reactions with low-energy beams of rare isotopes. A beam from the coupled cyclotron facility is stopped in a gas stopping system, charge bred in an Electron Beam Ion Trap (EBIT), and then reaccelerated in a compact superconducting LINAC. At present the beam repetition rate at the ReA targets is the same as the LINAC RF frequency of 80.5 MHz. A lower frequency would be desirable for many types of experiments using time of flight data acquisitions. Studies were undertaken to investigate possible methods of reducing the beam frequency with minimal reduction in overall beam current. This paper reports the results of preliminary design studies of such a low frequency prebuncher designed to increase the pulse separation and minimize bunch lengths at the detector.

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THPME052

Measurement of the Longitudinal Acceptance of the ReA RFQ

rfq, simulation, ion, injection

3346

D.M. Alt, S.W. Krause, A. Lapierre, D. Leitner, S. Nash, R. Rencsok, J.A. Rodriguez, M.J. Syphers, W. Wittmer
NSCL, East Lansing, Michigan, USA

The ReA reaccelerator facility at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) will provide a unique capability to study reactions with low-energy beams of rare isotopes. A beam from the coupled cyclotron facility is stopped in a gas stopping system, charge bred in an Electron Beam Ion Trap (EBIT), and then reaccelerated in a compact superconducting LINAC. The beam is injected into the LINAC by a room-temperature Radio Frequency Quadrupole (RFQ) combined with an external Multiharmonic Buncher. (MHB) In preparation for future upgrades to the capabilities of the ReA, an accurate determination of the longitudinal acceptance of the RFQ was conducted using a stable ion beam from a test source. This paper presents the results of the acceptance measurement, including empirical confirmation of a predicted asymmetry in the shape of the acceptance window.

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THPME053

Cost Rationales for an SRF Proton Linac

cavity, proton, hardware, SRF

3349

F. Marhauser
Muons, Inc, Illinois, USA

Rationales to assess and minimize costs for a Superconducting Radio Frequency (SRF) proton linac are outlined. Operating frequency, velocity profile and temperature are regarded as variables when applicable. Hardware plus labor costs for cavities and cryomodules as well as expenditures for facility infrastructures including cryogenic systems, conventional facilities, and relevant subsystems are estimated. The focus is on the assessment of a 10 MW, 1 GeV Continuous Wave (CW) linac for an Accelerator Driven Subcritical Reactor (ADSR)

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THPME057

Calculations of Halo in TraceWin Code

emittance, diagnostics, beam-losses, simulation

3361

N. Pichoff, P.A.P. Nghiem, D. Uriot
CEA/DSM/IRFU, France
M. Valette
CEA/IRFU, Gif-sur-Yvette, France

The TraceWIN code is used to simulate the dynamics of the particles and to design linear particle accelerators. The growth of rms emittance along the accelerator is often used to estimate the quality of a design. For high beam powers, the aim is also to limit the production of halo in order to keep particle losses under a requested limit. We present in this article the different ways to quantify this halo in TraceWin.

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THPME061

Present Status of J-PARC - after the Shutdown due to the Radioactive Material Leak Accident-

operation, power-supply, injection, target

3373

T. Koseki
KEK, Ibaraki, Japan
K. Hasegawa
JAEA/J-PARC, Tokai-mura, Japan

In J-PARC, a radioactive material leak accident occurred at the Hadron Experimental Facility on May 23, 2013. The accident was triggered by a malfunction of the slow extraction system of the Main Ring synchrotron. After seven-month long shutdown due to the accident, beam operation of the linac was restarted in December 2013. In this paper, the most recent status of the beam operation is presented.

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THPME063

Residual Dose with 400 MeV Injection Energy at J-PARC Rapid Cycling Synchrotron

injection, operation, vacuum, synchrotron

3379

K. Yamamoto, N. Hayashi, M. Kinsho
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Last summer shutdown J-PARC RCS injection energy was upgraded from 181 MeV to 400 MeV. We report the effect of the injection energy upgrade on the residual dose in the RCS.

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THPME064

Progress and Status of the J-PARC 3GeV RCS

injection, operation, vacuum, power-supply

3382

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

Big issue for the J-PARC 3GeV RCS was displacement of main magnets caused by last big earthquake because this made beam loss more than 400 kW beam power. Since realignment of main magnet and other components was essential to realize higher beam power and stable operation, this work has been done last maintenance period. To minimize amount of realignment work, we decided that not all components moved to designed regular potions but also minimum components moved to the position which was secured design acceptance 486 π mm mrad. Almost all components which are main magnets, rf cavities, and extraction magnets had to be moved in the range of 10 mm for horizontal, 3 mm for vertical and 9 mm for longitudinal, respectively. It was not necessary for the components installed in injection straight line to move because displacement of these components was less than ± 0.2 mm. At same time 400 MeV injection upgrade work should be done. Beam commissioning is planned from the middle of January 2014. The progress and status of the RCS in J-PARC are presented.

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THPME070

Status of the LIU Project at CERN

injection, ion, luminosity, extraction

3397

K. Hanke, H. Damerau, A. Deleu, A. Funken, R. Garoby, S.S. Gilardoni, N. Gilbert, B. Goddard, E.B. Holzer, A.M. Lombardi, D. Manglunki, M. Meddahi, B. Mikulec, E.N. Shaposhnikova, M. Vretenar
CERN, Geneva, Switzerland

CERN has put in place an ambitious improvement programme to make the injector chain of the LHC capable of supplying the high intensity and high brightness beams requested by the High-Luminosity LHC (HL-LHC) project. The LHC Injectors Upgrade (LIU) project comprises a new Linac (Linac4) as well as major upgrades and renovations of the PSB, PS and SPS synchrotrons. The heavy ion injector chain is also included, adding Linac3 and LEIR to the list of accelerators concerned. This paper reports on the work completed during the first long LHC shutdown, and outlines the further upgrade path.

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THPME075

FNAL - The Proton Improvement Plan (PIP)

booster, proton, operation, rfq

3409

W. Pellico, K.A. Domann, F.G. Garcia, K. E. Gollwitzer, K. Seiya, R.M. Zwaska
Fermilab, Batavia, Illinois, USA

Funding: The United States Department of Energy
The FNAL Proton Source is currently undergoing a major improvement effort. A plan has been developed and is underway to increase Proton Source throughput while maintaining good availability and acceptable residual activation. The plan addresses hardware modifications to increase repetition rate and improve beam loss while ensuring viable operation of the proton source through 2025. The PIP goals will enable Linac/Booster to: Deliver 2.25·10¹⁷ protons per hour with a 15 HZ cycle rate Availability greater than 85% Maintain residual activation at acceptable levels. The work has been progressing on schedule and is expected to finished by 2018.

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THPME079

Beam Diagnostics and Control for the AREAL RF Photogun Linac

controls, diagnostics, gun, electron

3418

G.A. Amatuni, B. Grigoryan, A. Lorsabyan, N. Martirosyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, A. Vardanyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
K. Manukyan
YSU, Yerevan, Armenia

Advanced Research Electron Accelerator Laboratory (AREAL) based on photo cathode RF gun is under construction at CANDLE. In current stage the gun section is under commissioning (phase 1). This paper presents the main characteristics of gun section beam diagnostics and the architecture of AREAL control system. The diagnostic system includes the measurements of the beam main parameters and its longitudinal and transverse phase space characteristics. The results of the facility first phase commissioning are summarized from the beam diagnostic and control point of view.

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THPME081

Plans for an Australian XFEL Using a CLIC X-band Linac

storage-ring, synchrotron, emittance, FEL

3424

M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu
SLSA, Clayton, Australia
R. Corsini, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland

Preliminary plans are presented for a sub-Angstrom wavelength XFEL at the Australian Synchrotron light source site. The design is based around a 6 GeV x-band linac from the CLIC Project. One of the motivations for the design is to have an XFEL co-located on the site with existing storage ring based synchrotron light source. The desire and ability of the Australian photon science community to win beamtime on existing XFELs has lead to this design study to plan for a future machine in Australia. The technology choice is also driven by the Australian participation in the CLIC Collaboration and the local HEP community.

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THPME100

The Mechanical Design of the BPM Inter-tank Section for P-linac at FAIR

cavity, proton, impedance, pick-up

3474

M.H. Almalki, R. M. Brodhage, P. Forck, W. Kaufmann, O.K. Kester, P. Kowina, T. Sieber
GSI, Darmstadt, Germany
M.H. Almalki, R. M. Brodhage, O.K. Kester
IAP, Frankfurt am Main, Germany
M.H. Almalki
KACST, Riyadh, Kingdom of Saudi Arabia
J. Balaguer
CEA/IRFU, Gif-sur-Yvette, France
P. Girardot, C.S. Simon
CEA/DSM/IRFU, France

At the planned Proton LINAC at the FAIR facility, four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the 30 m long FAIR p-LINAC. The LINAC comprises of crossbar H-mode (CH) cavity to accelerate a 70 mA proton beam up to 70 MeV at frequency of 325 MHz. At four locations, the BPMs will be an integral part of the inter-tank section between the CCH and CH cavities within an evacuated housing. As the BPM centre is only 48 mm apart from the upstream cavity boundary, the rf-background at the BPM position, generated by the cavity must be evaluated. In this paper the mechanical design of the BPM for the inter-tank section is presented and the rf-noise at the BPM location is discussed.

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THPME116

Studies on a Diagnostic Pulse for FLASH

optics, betatron, diagnostics, experiment

3506

F. Mayet, R.W. Aßmann, S. Schreiber, M. Vogt
DESY, Hamburg, Germany

The long-term stability of the beam optics at FLASH is crucial for all connected experiments and the operation of the new second beamline FLASH2. It is therefore desirable to have a simple procedure to monitor the beam optics routinely and at the same time minimally invasive. This way user operation is not disturbed. An automated procedure, which has been successfully employed at the SLAC linac is presented in the context of FLASH. The betatron oscillations of selectively kicked pulses are recorded using BPMs at a fixed time interval. An online algorithm is then used to extract the betatron phase advance, as well as potential growth of the betatron oscillation amplitude and the Twiss parameters beta and alpha. Using this method, the long-term beam optics stability can be monitored in order to identify potential sources of drifts.

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THPME123

Electro-optical Bunch Length Monitor for FLUTE: Layout and Simulations

electron, laser, simulation, gun

3527

A. Borysenko, E. Hertle, N. Hiller, V. Judin, B. Kehrer, S. Marsching, A.-S. Müller, M.J. Nasse, R. Rossmanith, R. Ruprecht, M. Schuh, M. Schwarz, P. Wesolowski
KIT, Karlsruhe, Germany
B. Steffen
DESY, Hamburg, Germany

Funding: This work is funded by the European Union under contract PITN-GA-2011-289191
A new compact linear accelerator FLUTE is currently under construction at Karlsruhe Institute of Technology (KIT) in collaboration with DESY and PSI. It aims at obtaining femtosecond electron bunches (~1fs - 300 fs) with a wide charge range (1 pC - 3 nC) and requires a precise bunch length diagnostic system. Here we present the layout of a bunch length monitor based on the electro-optic technique of spectral decoding using an Yb-doped fiber laser system (central wavelength 1030 nm) and a GaP crystal. Simulations of the electro-optic signal for different operation modes of FLUTE were performed and main challenges are discussed in this talk. This work is funded by the European Union under contract PITN-GA-2011-289191

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THPME132

Generation and Diagnosis of Ultrashort Electron Bunches from a Photocathode RF Gun Linac

electron, detector, gun, laser

3553

I. Nozawa, M. Gohdo, K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan
H. Kobayashi
KEK, Ibaraki, Japan

Ultrashort electron bunches are essential for time-resolved measurement methods such as pulse radiolysis* from the viewpoint of time resolutions. On the other hand, generation of electro-magnetic wave in the THz range using short electron bunches has been investigated**. Frequency spectra of coherent transition radiation (CTR) emitted by an electron bunch depend on bunch form factor (BFF), which is expressed by Fourier coefficients of longitudinal distribution in the electron bunch. In this study, the bunch length measurement was demonstrated by analyzing THz-waves generated by CTR. Femtosecond electron bunches were generated by a laser photocathode RF gun linac and magnetic bunch compressor. THz-waves generated by CTR, which was emitted on an interface of an aluminum mirror along the beam trajectory, were transported to a Michelson interferometer. The bunch length was measured by analyzing interferogram, which was an infrared detector output as a function of a moving mirror position. Finally, the bunch length was measured according to fitting curves for the interferogram near the centerburst***. Minimum bunch length of 1.3 fs was obtained at a bunch charge of ~1 pC.
*J. Yang et al., Nucl. Instrum. Meth. A 556, 52 (2006).
**K. Kan et al., Appl. Phys. Lett. 99, 231503 (2011).
***A. Murokh et al., Nucl. Instrum. Meth. A 410 (1998).

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THPME138

Dynamic Comparison With XAL and Tracewin Based on the Injector-I of China ADS Test Stand

lattice, cavity, cryomodule, solenoid

3572

Y.L. Zhao, P. Cheng, H. Geng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan
IHEP, Beijing, People's Republic of China

The injector scheme I (injector-I) of China ADS test stand is a superconducting Linac which accelerates 10mA beam to 3.2MeV, 5MeV, 10MeV, and then transports it to the dump. The dump line is designed to meet the requirement of beam expansion at the three different energies. The XAL from SNS was selected for the commissioning of China ADS. Because the beam current is so high, the nonlinear space charge force cannot be omitted. As we know, XAL calculates the space charge force with linear resolver. So, whether it could display the beam exactly enough is an important issue to consider. As a preparation for beam commissioning, the virtual accelerator in XAL frame was built and tested. Here in this paper, the envelopes of the 5MeV and 10MeV lattices from general XAL mpx application are shown and compared with the multiparticle tracking code TraceWin.

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THPME139

Emittance Measurement with Wire Scanners at CADS MEBT1

emittance, rfq, quadrupole, space-charge

3575

H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The C-ADS project has started beam commissioning. The ion source and LEBT has been commissioned successfully, while the RFQ is under conditioning. The Medium Energy Beam Transport line-1 (MEBT) is the place where extensive beam parameter measurement will be carried out. Beam emittance is one of the most critical parameters which have to characterized. In the C-ADS injector-I, the MEBT-1 has installed three wire scanners to measure the beam sizes. The transverse emittance measurement method using the wire scanners will be discussed in detail in this paper.

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THPME141

Design of Beam Intensity Measurement System in Injector for HLS II

electron, controls, monitoring, instrumentation

3581

C. Cheng, P. Lu, B.G. Sun, K. Tang, J. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new beam intensity measurement (BIM) system has been developed and has been used in the upgrade project of HLS II. After the upgrading is accomplished, electron energy in Injector endpoint will increase from 200MeV to 800MeV to achieve the goal of top-off injector. Meanwhile, macro pulse width changes from 1us to 1ns and peak intensity from 50mA to 1A approximately. So three fast current transformers (FCTs) and two integrating current transformer (ICTs) are installed in Linac and Transport Line to measure single pass beam parameters. In this article, off-line calibration of beam transformer is elaborated. Since the fast pulse signals from beam transformer will be hugely distorted after they transmit from Injector vacuum chamber to the Injector beam diagnostic centre room after hundreds of meters long LMR-400 cable, signal recovery algorithm based on FFT/IFFT is used to re-appear the true original signal and calculate the calibration efficient. In the end, resolution and measurement result of the BIM system is presented.

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THPME142

Design of the Beam Profile Monitors for THz Source Based FEL

controls, FEL, target, LabView

3584

J. Liu, P. Lu, B.G. Sun, K. Tang, J.G. Wang, J. Xu, Y.L. Yang, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Design of the Beam Profile Monitors for THz Source Based FEL* J. Liu, P. Lu, B. G. Sun#, Y. J. Pei, Y. L. Yang, Z.R. Zhou, J. G. Wang, K. Tang, J. Xu NSRL, School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230029, P. R. China Abstract To meet requirements of high performance THz-FEL, a compact FEL facility was proposed. In order to characterize the beam, some beam profile monitors were designed. There are four flags for beam profiles in Linac，one pop-in monitor for high precision beam profile inside a small-gap undulator, and two screens to measure the beam energy spread and emittance of Linac. On one hand, we need to use software to control the position of these profile monitors, on the other hand, we need screens to display the results. This paper describes how to design and control these monitors, as well as how to measure the beam parameter.

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THPME144

Stripline Beam Position Monitor for THz Source Based FEL

brilliance, electronics, impedance, controls

3590

J. Xu, L. Li, J. Liu, P. Lu, Y.J. Pei, B.G. Sun, K. Tang, J.G. Wang, F.F. Wu, H. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A 14MeV Linac with both the micro-pulse repetition rate 2856MHz and the macro-pulse width 6us for the THz Source Based FEL was proposed. In order to measure the beam position, a stripline beam position monitor (BPM) was designed, and a commercial BPM electronics Libera Brilliance Single Pass was adopted. As the input carrier frequency of the BPM electrode signal is 2856MHz, but the operating frequency of the Libera Brilliance Single Pass is 500MHz, so a front-end electronics was needed before the electrode signals feed into Libera Brilliance Single Pass. The front-end electronics was designed to make the BPM electrode signals of 2856MHz convert to 500MHz.

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THPME148

Beam Dynamics Issues for a Superconducting Linear Accelerator-based High Power Heavy Ion Machine

emittance, ion, cavity, proton

3602

J.G. Hwang, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
H. Jang, D. Jeon, H.J. Kim, H.J. Kim
IBS, Daejeon, Republic of Korea

The driver linac of RAON heavy ion accelerator based on the superconducting technology, which consists of a 28 GHz ECR ion source, a low energy beam transport line, a RFQ accelerator, a medium energy beam transport line, a low energy linac(SCL1), a charge stripping section and a high energy linac(SCL2), will produce the stable ion beam from proton with 600 MeV to uranium with 200 MeV/u. Many beam dynamics issues such as beam steering effect due to QWR cavities with the peak electric field of 35 MV/m, emittance growth in charge stripper due to the straggling effect, parametric resonance and envelope instability were verified to design the high power heavy ion machine which can produce the high quality beam. In this presentation, we explain our study results for achieving longitudinal acceptance larger than 27 keV/u-ns for the stable operation and minimizing the emittance growth less than 30 % in the superconducting linac for high quality beam at the in-flight target.

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THPME149

Beam Dynamics Issues in the Post Accelerator for the Rare Isotope Ion Beams from ISOL System in RISP

ion, emittance, ISOL, simulation

3605

J.G. Hwang, S.W. Jang, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
B.H. Choi, D. Jeon, H.J. Kim, H.J. Kim, I. Shin
IBS, Daejeon, Republic of Korea
L. Lee
KNU, Deagu, Republic of Korea

The accelerator for RISP, which is the superconducting technology based heavy ion linear accelerator construction project, is composed mainly of the driver linac for stable ion beam from an ECR ion source and post linac for unstable ion from an ISOL system. The post accelerator can accelerate the unstable ion beams up to 16.5 MeV/u for 132Sn and 16.0 MeV/u for 58Ni, which has the ratio of mass to charge, A/q, of 8.3. The unstable ion beam such as 132Sn from an ISOL system has the large transverse and longitudinal emittances. Hence acceptance and envelope of the post accelerator should optimize for stable operation. The beam was transported by the post-to-driver transport (P2DT) line which consists of a charge stripper, two charge selection sections and a telescope section with the bunching cavities. In this presentation, we will show the criteria for the design of the post accelerator and result of beam tracking simulation from the low energy transport line to the end of post linac. The initial coordinates of the particles were acquired by the tracking simulation from the low energy beam transport (LEBT) line to the medium energy beam transport (MEBT) line.

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THPME160

Design, Implementation and Preliminary Test Results of the ESS Beam Current Monitor System

FPGA, interface, electronics, timing

3638

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
J.L. Crisp
FRIB, East Lansing, Michigan, USA
U. Legat, K. Strniša
Cosylab, Ljubljana, Slovenia
M. Werner
DESY, Hamburg, Germany

The Beam Current Monitor system of the ESS linac will be mainly based on AC Current Transformers. The BCM system will be used to monitor the beam current and charge in absolute and differential modes. The differential current measurement is also intended for detecting large and sudden beam losses and acting on the Machine Interlock System (MIS), especially in areas where Beam Loss Monitors cannot be reliably used. A demo BCM based on a Bergoz ACCT and MTCA.4 electronics has been procured and integrated into EPICS. A VHDL code has been developed and successfully tested for the required FPGA signal processing including droop compensation, filtering, DC level correction and interfacing to the MIS. This paper gives an overview of the current status of the BCM system design and implementation as well as some preliminary test results in absolute and differential modes.

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THPME165

Studies into Beam Loss Patterns at European Spallation Source

simulation, quadrupole, detector, radiation

3650

M. Jarosz, A. Jansson, L. Tchelidze
ESS, Lund, Sweden

Funding: This project is funded by the European Union under contract PITN-GA-2011-289485.
The linear accelerator of European Spallation Source will produce 5 MW proton beam. Beam of this power will likely generate significant losses along the beamline. To study these losses, a coherent model of the whole machine is being made using custom generator. This model is used to perform Monte Carlo simulations of the propagation of the accelerated beam and the losses in the MARS code system. Preliminary simulations utilizing the uniform beam loss distribution were done. More detailed simulations based on the various different loss patterns focused around hot spots in magnets were also performed and their results compared. This confirmed the limit of 0.5 W/m average heat load on accelerating cavities foreseen by the cooling requirements. Additional studies investigated the dose absorbed by fragile cooling system’s elements during the normal operation of the facility defining their radiation resistance to the levels of few kGy/y. Further simulations will also give the information about the expected beam loss detectors signal at possible locations. These data will be further analysed using custom algorithms.

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THPME166

System Overview and Current Status of the ESS Beam Position Monitors

electronics, simulation, detector, quadrupole

3653

H. Hassanzadegan, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
D. Lipka, M. Werner
DESY, Hamburg, Germany
A. Young
SLAC, Menlo Park, California, USA

It is planned to install more than 140 button BPMs along the ESS linac. The BPMs will be used to measure the beam position and phase in all foreseen beam modes and to provide input to the Machine Interlock System. The phase measurement is mainly intended for cavity tuning and Time-Of-Flight energy measurements. A customized BPM detector based on the European XFEL button style has been designed for the cold linac through a collaboration with DESY. Large buttons with diameters up to 40 mm are foreseen to provide enough S/N ratio not only with the nominal beam, but also with a low-current or a de-bunched beam. A demo MTCA.4 system has been procured and successfully integrated into EPICS. Also, a customized Rear Transition Module for down-mixing the BPM signals will be developed with SLAC. Electronics tests with a BPM test bench are currently going on at ESS. BPM installation in the linac is foreseen for 2017 and afterwards.

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THPME167

Development of Non-invasive Transverse Profile Monitors for the ESS Linac

proton, radiation, photon, detector

3656

C. Roose, C. Böhme, I. Dolenc Kittelmann, A. Jansson, C.A. Thomas
ESS, Lund, Sweden
A. Källberg
Stockholm University, Stockholm, Sweden

The European Spallation Source (ESS) consists of a partly superconducting linac which will deliver a 2 GeV proton beam to a rotating tungsten target. In this way, the ESS will be the world's most powerful neutron source. To measure the proton beams transverse profile at high intensity, the ESS develops two types of non-invasive profile devices. The first monitor is based on luminescence of the residual gas, the second one on ionization of the same gas. The latest developments of these profile monitors will be presented.

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THPME170

Prospects for Longitudinal Phase-space Measurements at the MAX IV Linac

electron, FEL, simulation, extraction

3665

F. Curbis, O. Karlberg, S. Thorin, S. Werin
MAX-lab, Lund, Sweden

Knowing the longitudinal phase space of an electron beam is one of the most important and crucial issues in short-pulses linacs. To achieve this task expensive and rather complicated setups (like transverse deflecting cavities) are usually implemented. The MAX IV 3 GeV linac will be used to inject into two rings and to drive a short pulse facility. Nevertheless, a more deep understanding of the beam quality would be useful especially in view of an upgrade as FEL driver. Another interesting aspect is to evaluate how the double-achromat bunch compressors are performing. We are studying how to implement off-phase acceleration: last part of the linac will be set at zero-crossing phase and the transfer line to the 3 GeV ring could be used as energy spectrometer to retrieve the bunch profile. In the present configuration of the MAX IV linac this procedure will allow to check the bunch length after the first bunch compressor. Since it is work in progress, in this contribution we present a sketch of the measurement and the feasibility of the method will be explored by means of simulations.

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THPME179

Beam Diagnostics Measurements at 3MeV of the LINAC4 H⁻ Beam at CERN

emittance, DTL, electron, quadrupole

3694

F. Zocca, J.C. Allica Santamaria, M. Duraffourg, G.J. Focker, D. Gerard, B. Kolad, L. Lenardon, M. Ludwig, U. Raich, F. Roncarolo, M. Sordet, J. Tan, J. Tassan-Viol, C. Vuitton
CERN, Geneva, Switzerland
A. Feschenko
MIPT, Dolgoprudniy, Moscow Region, Russia
A. Feschenko
RAS/INR, Moscow, Russia

As part of the CERN LHC injector chain upgrade, LINAC4 will accelerate H⁻ ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been first commissioned in a dedicated test stand and are now tested in the LINAC4 tunnel. Diagnostics devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The movable test bench also includes a spectrometer that allows measuring the beam energy spread in conjunction with a wire grid. The present understanding of the instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

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THPME190

A Fibre Coupled, Low Power Laserwire Emittance Scanner at CERN LINAC4

laser, emittance, detector, background

3725

S.M. Gibson, G.E. Boorman, A. Bosco, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
T. Hofmann, F. Roncarolo
CERN, Geneva, Switzerland
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The new LINAC4 will accelerate H⁻ ions to 160 MeV and ultimately replace the existing 50 MeV LINAC2 in the injector chain for the LHC upgrade. During commissioning in 2013, a laserwire scanner and diamond strip detector were installed for non-invasive emittance measurements of the 3 MeV H⁻ beam. Synergy with the 3 MeV H⁻ Front End Test Stand at RAL, has stimulated collaborative development of a novel laserwire system. A low peak power (8kW) pulsed laser is fibre-coupled for remote installation and alignment free operation. Motorized focusing optics enable remote control of the thickness and position of the laserwire delivered to the vacuum chamber, in which the laser light neutralises a small fraction of H⁻ ions. Undeflected by a dipole magnet, these H atoms drift downstream, where their spatial profile is recorded by a highly sensitive diamond strip detector with ns-time resolution. We present first tests of the laserwire emittance scanner, including measurements of the photo detachment signal with respect to the background from residual gas interactions. The first laserwire transverse beam profile and emittance measurements are compared with conventional slit-grid diagnostics.

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THPRI002

DAΦNE General Consolidation and Upgrade

controls, vacuum, detector, quadrupole

3760

C. Milardi, D. Alesini, S. Bini, B. Buonomo, S. Cantarella, A. De Santis, G.O. Delle Monache, G. Di Pirro, A. Drago, L.G. Foggetta, O. Frasciello, A. Gallo, A. Ghigo, F. Iungo, C. Ligi, L. Pellegrino, R. Ricci, U. Rotundo, C. Sanelli, G. Sensolini, A. Stecchi, A. Stella, M. Zobov
INFN/LNF, Frascati (Roma), Italy
R. Gargana, A. Michelotti
Consorzio Laboratorio Nicola Cabibbo, Frascati, Italy

In the first six months of 2013 the KLOE detector has been upgraded inserting new detector layers in the inner part of the apparatus, around the interaction region. The long shutdown has been used to undertake a general consolidation program aimed at improving the Φ-Factory operation stability and reliability and, in turn, the collider uptime. In this context several systems have been revised and upgraded, new diagnostic elements have been installed, some critical components have been modified and the interaction region mechanical support structure design has been developed to improve its mechanical stability and to deal with the weight added by the new detector layers.

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THPRI015

DAΦNE Transfer Line for KLOE-2 Physics Run

injection, controls, detector, electron

3797

A. De Santis, B. Buonomo, S. Cantarella, P. Ciuffetti, G. Di Pirro, A. Drago, L.G. Foggetta, A. Ghigo, C. Milardi, R. Ricci, U. Rotundo, M. Serio, A. Stecchi, A. Stella
INFN/LNF, Frascati (Roma), Italy
A. Michelotti
Consorzio Laboratorio Nicola Cabibbo, Frascati, Italy

The transfer lines of the DAΦNE accelerator complex have been revised and optimized in view of the forthcoming KLOE-2 physics run. The transfer lines consolidation activities involved low level systems, diagnostics tools and control system hardware modifications for the magnetic element switching polarity during the injection procedure. Transfer lines optics has been reviewed and optimized as well by a systematic study based on a MAD-X model. The work done determined a substantial improvement in the transfer lines stability and reproducibility, speeded up the injection procedure with a considerable reduction on the background hitting the experimental detector during the beam injection process.

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THPRI016

Pulse Based Data Archive System and Analysis for Current and Beam Loss Monitors in the J-PARC RCS

vacuum, injection, ion-source, ion

3800

N. Hayashi, S. Hatakeyama, K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The data archive system in the J-PARC 25-Hz Rapid-Cycling Synchrotron (RCS) records the beam intensity and the beam loss monitor (BLM) pattern for all pulses. The system is based on the common memory and utilizes the timing system of the J-PARC. Although its time resolution is limited, it is useful to detect rare events or phenomena appearing with only higher accelerator repetition. Using these data, the stability of the beam intensity, particularly ion source can be examined. The relation between BLM patterns and its causes can be studied pulse-by-pulse basis and it would make use of future improvements.

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THPRI019

Reliability and Availability Modeling for Accelerator Driven Facilities

software, simulation, operation, vacuum

3803

O. Rey Orozko, E. Bargalló, A. Nordt
ESS, Lund, Sweden
A. Apollonio, R. Schmidt
CERN, Geneva, Switzerland

Accelerator driven facilities are and will have to be designed to a very high level of reliability and beam availability to meet expectations of the users and experiments. In order to fulfill these demanding requirements on reliability and overall beam availability, statistical models have been developed. We compare different statistical reliability models as well as tools in terms of their performance, capacity and user-friendliness. In addition we also benchmarked some of the existing models. We will present in detail a tool being used for LHC and LINAC4 which is based on the commercially available software package Isograph and a tool using Excel, which was developed in house for ESS-systems. The impact of an early reliability modeling on the design of mission critical systems will be presented as well.

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THPRI020

Availability Studies for Linac4 and Machine Protection Requirements for Linac4 Commissioning

operation, target, hardware, ion

3807

A. Apollonio, S. Gabourin, C. Martin, B. Mikulec, B. Puccio, J.L. Sanchez Alvarez, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

Linac4 is one of the key elements in the upgrade program of the LHC injector complex at CERN, assuring beams with higher bunch intensities and smaller emittance for the LHC and many other physics experiments on the CERN site. Due to the demand of continuous operation, the expected availability of Linac4 needs to be carefully studied already during its design phase. In this paper an overview of the relevant systems impacting on Linac4 machine availability is given: the various system failure modes are outlined as well as their impact on the total yearly machine downtime. Machine Protection Systems (MPS) play a significant role in reducing the risk associated to each failure mode and are therefore important for reaching the target availability. The Linac4 MPS requirements, with particular focus on the different commissioning phases, are discussed.

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THPRI040

Study of Geometrical Parameters and their Tolerances in Optimization of Accelerating Cells of Side Coupled Linac

cavity, simulation, impedance, electron

3850

S. Zarei
Nuclear Science and Technology Research, InstituteRadiation Application School, Tehran, Iran
F. AbbasiDavani, S. Ahmadiannamin, F. Ghasemi
sbu, Tehran, Iran
M. Lamehi Rashti
IPM, Tehran, Iran

After choosing the suitable geometry for accelerating cavity, evaluation of geometrical parameters effects on radio frequency characteristics is essential. In this paper after study of priority of geometrical parameters in optimization of accelerating cells of Side Coupled Linac, according to obtained results, new design of s-band accelerating cavity is suggested. By frequency sensitivity study of new dimensions, we can choose best technique to tune the accelerating cavity during magnetic coupling-hole adjustment.

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THPRI042

Design and RF Test of Damped C-Band Accelerating Structures for the ELI-NP Linac

HOM, damping, operation, vacuum

3856

D. Alesini, S. Bini, R. D. Di Raddo, V.L. Lollo, L. Pellegrino
INFN/LNF, Frascati (Roma), Italy
L. Ficcadenti, V. Pettinacci
INFN-Roma, Roma, Italy
L. Palumbo
URLS, Rome, Italy
L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy

The linac energy booster of the European ELI-NP proposal foresees the use of 12 traveling wave C-Band structures, 1.8 m long with a field phase advance per cell of 2pi/3 and a repetition rate of 100 Hz. Because of the multi-bunch operation, the structures have been designed with a damping of the HOM dipoles modes in order to avoid beam break-up (BBU). They are quasi-constant gradient structures with symmetric inputs couplers and a strong damping of the HOM in each cell. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce their cost. In the paper we shortly review the whole design criteria and we illustrate the low and high power RF test results on prototypes that shown the feasibility of the structure realization and the effectiveness of the HOM damping.

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THPRI043

Thermal-mechanical Analysis of the RF Structures for the ELI-NP Proposal

gun, RF-structure, cathode, HOM

3860

V. Pettinacci
INFN-Roma, Roma, Italy
D. Alesini, L. Pellegrino
INFN/LNF, Frascati (Roma), Italy
L. Palumbo
URLS, Rome, Italy

The room temperature RF structures in the ELI-NP Linac will operate in multi-bunch with high repetition rate (100 Hz). For these reasons they are subject to some kW of power dissipated on the internal cavities surfaces. The resulting thermal deformation of the cavities shapes could imply variations in their electromagnetic fields. To limit these effects and optimize the cooling design, a fully coupled ElectroMagnetic- Thermal-Mechanical analysis has been performed on the S-Band Radiofrequency Gun and on the C-Band multi-cell structures. In the paper the study done in Ansys Workbench with HFSS and Ansys Mechanical is reviewed

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THPRI044

Vacuum Waveguide System for SPring-8 Linac Injector Section

vacuum, electron, klystron, operation

3863

T. Taniuchi, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, S. Suzuki, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan

An SF6 waveguide system for the injector section of SPring-8 linac has been replaced in a vacuum waveguide system including a newly developed vacuum circulator and an isolator. This paper describes developed RF components, a waveguide configuration and an RF conditioning of the system.

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THPRI047

Large-aperture Travelling-wave Accelerator Structure for Positron Capture of SuperKEKB Injector Linac

positron, operation, acceleration, solenoid

3872

S. Matsumoto, T. Higo, K. Kakihara, T. Kamitani, M. Tanaka
KEK, Ibaraki, Japan

Comparing to the previous KEKB, the four-times higher charge of 4 nC per bunch is required for the injector linac of SuperKEKB. Not only a flux concentrator will be introduced but also the physical aperture of the downstream six 2m-long accelerator structures was increased as large as 30mm in diameter. We call these structures as LAS, “Large Aperture S-band” structure. The resultant higher RF group velocity of about 3% makes the acceleration gradient lower. In the nominal acceleration system, a 40MW klystron with SLED feeds four 2m-long accelerator structures producing 20MV/m acceleration field. The acceleration gradient higher than 14 MV/m is required for the very first two LAS structures to suppress the satellite bunches. This gradient is obtained by feeding only two LAS structures. Initially, ten LAS structures were installed and the RF processing has partly started. In the present paper, we firstly describe the acceleration system design and then present the processing characteristics through the RF processing without beam and with beam.

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THPRI049

Engineering Design of the RF Input Couplers for C-ADS RFQ

rfq, cavity, impedance, operation

3878

L.P. Sun, Y. He, A. Shi, C. Zhang, Z.L. Zhang
IMP, Lanzhou, People's Republic of China

A new coupler with the special ceramic window has been developed at IMP, CAS (Institute of Modern Physics, Chinese Academy of Sciences), operating at 30 kW/162.5 MHz in CW mode for an one-meter prototype cavity, which can provide all kinds of experiences to the real four-meter cavity including EM simulation, power conditioning, cooling consideration and so on. Now, the beam experiments on prototype cavity have been completed and the results show the simulation and the measurements of coupler were in the good agreement. The special bowl-type ceramic window can promote S parameter and reduce sparking risk for beam commissioning stably. A detailed electromagnetic design and measured results of the coupler will be presented in the paper.

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THPRI062

CW Room Temperature Re-buncher for the PIP-II Linac Front End

cavity, proton, beam-transport, experiment

3914

I. Terechkine, M. Chen, I.V. Gonin, S. Kazakov, T.N. Khabiboulline, L. Ristori, G.V. Romanov
Fermilab, Batavia, Illinois, USA

At Fermilab there is a plan for improvements to the Fermilab accelerator complex aimed at providing a beam power capability of at least 1 MW on target. The essential element of the plan (the Proton Improvement Plan II – PIP-II) is a new 800 MeV superconducting linac. The PIP-II linac includes a room temperature front-end and high energy part based on five types of superconducting cavities used to cover the entire velocity range required for beam acceleration. The room temperature front end is composed of an ion source, low energy beam transport line (LEBT), radio frequency quadrupole (RFQ), and a medium energy beam transport line (MEBT). The paper reports RF design of the re-buncher for MEBT along with thermal analysis of the cavity.

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THPRI073

Achieving Higher Energies via Passively Driven X-band Structures

cavity, impedance, electron, FEL

3933

T. Sipahi, S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA

Due to their higher intrinsic shunt impedance X-band accelerating structures significant gradients with relatively modest input powers, and this can lead to more compact particle accelerators. At the Colorado State University Accelerator Laboratory (CSUAL) we would like to adapt this technology to our 1.3 GHz L-band accelerator system using a passively driven 11.7 GHz traveling wave X-band configuration that capitalizes on the high shunt impedances achievable in X-band accelerating structures in order to increase our overall beam energy in a manner that does not require investment in an expensive, custom, high-power X-band klystron system. Here we provide the design details of the X-band structures that will allow us to achieve our goal of reaching the maximum practical net potential across the X-band accelerating structure while driven solely by the beam from the L-band system.

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THPRI074

Colorado State University (CSU) Accelerator and FEL Facility

laser, electron, controls, undulator

3937

S. Biedron, C. Carrico, A. D'Audney, J.P. Edelen, J. Einstein, C.C. Hall, J.R. Harris, K. Horovitz, J. Martinez, S.V. Milton, A.L. Morin, N. Sipahi, T. Sipahi, J.E. Williams, P.J.M. van der Slot
CSU, Fort Collins, Colorado, USA
P.J.M. van der Slot
Mesa+, Enschede, The Netherlands
P.J.M. van der Slot
Twente University, Laser Physics and Non-Linear Optics Group, Enschede, The Netherlands

The Colorado State University (CSU) Accelerator Facility will include a 6-MeV L-Band electron linear accelerator (linac) with a free-electron laser (FEL) system capable of producing Terahertz (THz) radiation, a laser laboratory, a microwave test stand, and a magnetic test stand. The photocathode drive linac will be used in conjunction with a hybrid undulator capable of producing THz radiation. Details of the systems used in CSU Accelerator Facility are discussed.

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THPRI075

S-Band Structure Study for the MaRIE Project

wakefield, coupling, dipole, impedance

3940

Z. Li, C. Adolphsen, M.V. Fazio, S.G. Tantawi, L. Xiao
SLAC, Menlo Park, California, USA

Funding: Work was supported by the US Department of Energy through the LANL/LDRD Program.
The Matter-Radiation Interactions in Extremes (MaRIE) facility proposed at LANL utilizes a 20-GeV electron linac to drive a 50-keV XFEL. Experimental requirements drive a need for multiple photon bunches over time durations of about 10 microsecond produced by a bunch train of interleaving 0.1 nC very low-emittance bunches with 2-nC electron bunches. The linac is required not only to provide high gradient and high efficient acceleration, but also a controlled wakefield profile to maintain the beam quality. In this paper, we explore the feasibility of using the S-Band technology to meet such acceleration requirements. We will present the design optimization and comparison of S-Band structures based on different design considerations.

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THPRI091

Machine Protection Considerations for BERLinPro

electron, vacuum, laser, diagnostics

3985

S. Wesch, M. Abo-Bakr, M. Dirsat, G. Klemz, P. Kuske, A. Neumann, J. Rahn, T. Schneegans
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin, and grants of Helmholtz Association
The Berlin energy-recovery-linac project BERLinPro at the HZB is a 50 MeV ERL test facility, which addresses physical and technological questions for future superconducting rf based high brightness, high current electron beam sources. The combination of a 100 mA cw beam, electron bunches with normalized emittances lower than 1 mm mrad and the magnet optics of BERLinPro leads to power densities capable to harm the accelerator components within microseconds if total beam loss occurs. Furthermore, continuous beam loss on the level of 10^-5 has to be controlled to avoid activation and to protect the SRF, beam diagnostics and other infrastructure components. In this paper, we present the evaluation of the required key parameters of the BERLinPro machine protection system and present its first conceptual design.

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THPRI097

A Retrospective View to the Magnet Interlock Systems at CERN

PLC, operation, interlocks, software

4001

I. Romera, P. Dahlen, R. Mompo, B. Puccio, M. Zerlauth
CERN, Geneva, Switzerland

Several thousands of both, superconducting and normal conducting magnets are in charge of guiding the particle beams in CERN’s accelerator complex. In order to protect the magnet and powering equipment from damage, dedicated magnet interlock and protection systems are deployed throughout the various accelerators and transfer lines. These systems have worked extremely well during the first years of LHC operation, providing highly dependable interlocking of magnet powering based on industrial COTS components. This paper reviews the performance of the more than 70 individual installations during the first LHC running period and compares the operational experience with the initial expectations of dependability. Additional improvements required to address specific operational needs and observed shortcomings are presented. Finally, we review the existing magnet interlock infrastructure in the LHC injector complex and the ongoing renovation works during the first long shutdown.

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THPRI101

Coupler Kick and Cavity Tilt Effects on Emittance Preservation in Linear Accelerators

emittance, wakefield, cavity, factory

4013

A.V. Tsakanian, G.A. Amatuni, B. Grigoryan, I.N. Margaryan, V.M. Tsakanov
CANDLE SRI, Yerevan, Armenia

The effects of the coupler kick and the cavity tilts on the beam dynamics in long linear accelerator are studied. The dispersive and wakefield caused beam emittance dilution are evaluated analytically using two particle model of the beam. The numerical simulations for the European XFEL project are presented.

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THPRI111

Higher Order Mode Absorbers for High Current ERL Applications

HOM, cavity, cryomodule, damping

4037

R.G. Eichhorn, J.V. Conway, Y. He, Y. Li, T.I. O'Connel, P. Quigley, J. Sears, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Efficient damping of the higher-order modes (HOMs) of the superconducting cavities is essential for any high current linac, especially for the proposed energy recovery linac at Cornell that aims for high beam currents and short bunches. This contribution will present the design and first result on the HOM absorbers built for the Main Linac Cryomodule (MLC).

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THPRI112

Basic Research on RF Absorbing Ceramics for Beam Line HOM Absorbers

HOM, damping, vacuum, higher-order-mode

4040

R.G. Eichhorn, P. Quigley, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
M. Carty
Alfred University, Alfred, New York, USA
J. Matteson, A. Rae
NanoMaterials Innovation Center LLC, Painted Post, USA

Higher Order Mode (HOM) absorbers for future high current machines have been a challenging component for many years. Even though many different materials are commercially, none of them seems to fully qualify for accelerator applications. Some of them are brittle or chippy, others porous, have small bandwidth of absorption, a high dc resistivity leading to charge-up or are unreliable in terms of batch to batch variations. Alfred University and Cornell University have recently partnered in developing a dedicated absorber ceramic material that tries to overcome these limitations. We will report on results from small samples of different compositions we produced based on SiC, graphene and graphite.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI112

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FRXCA01

State-of-the-art and Future Challenges for Machine Protection Systems

operation, injection, monitoring, diagnostics

4060

J. Wenninger
CERN, Geneva, Switzerland

Current frontier accelerators explore regimes of increasing power and stored energy, with beam energies spanning more than three orders of magnitude from the GeV to the TeV scale. In many cases the high beam power has to cohabit with superconducting equipment in the form of magnets or RF cavities requiring careful control of losses and of halos to mitigate quenches. Despite their large diversity in physics goals and operation modes, all facilities depend on their “Machine Protection Systems” (MPS) for safe and efficient running. This presentation will aim to give an overview of current MPS and on how the MPS act on or control the beams. Lessons from the LHC and other accelerators show that ever tighter monitoring of accelerator equipment and of beam parameters is required in the future. Such new monitoring systems must not only be very accurate but also be extremely reliable to minimize false alarms. Novel MPS ideas and concepts for linear colliders, high intensity hadron accelerators and to other high power accelerators will be presented.

Slides FRXCA01 [5.507 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-FRXCA01

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