IPAC2014 - List of Keywords (emittance)

Paper	Title	Other Keywords	Page
MOXBA01	Challenges in the Design of Diffraction-limited Storage Rings	lattice, photon, brightness, storage-ring	7
	R.O. Hettel SLAC, Menlo Park, California, USA
	This presentation reviews current developments in the design of ultra-low emittance lattices, the experience and challenges with the operation of low emittance lattices and the main technological problems. Beam dynamics issues and collective effects for ultra low emittance machines are also addressed.
	Slides MOXBA01 [6.969 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOXBA01
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MOYBA02	New Design Approaches for High Intensity Superconducting Linacs – The New ESS Linac Design	cryomodule, linac, cavity, klystron	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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MOOCA03	Design of High-power Graphene Beam Window	scattering, proton, target, Windows	45
	H.J. Wang, H.T. Jing, H. Qu, J.Y. Tang IHEP, Beijing, People's Republic of China
	Beam window is a key device in high-intensity hadron beam applications, and it is usually used to separate air or other gas environments in the end of beam vacuum duct. Compared with the usually-used window materials such as Inconel alloy, Aluminum alloy and so on, the graphene has extremely high thermal conductivity, high strength and high transparency to high-energy ions. With the maturation of large-size graphene manufacturing technology, we have studied this new-type window for MW-class proton beam. The thermal analyses by the theoretical formula and simulations based on FEA are presented in this paper. Simultaneously, the scattering effect and the lifetime are also discussed. The preliminary results are promising. The same material can also be possibly applied to other devices such as charge-exchange stripping foils, beam monitors and so on.
	Slides MOOCA03 [1.467 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOOCA03
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MOZB02	Advances in Photocathodes for Accelerators	electron, cathode, laser, experiment	48
	L. Cultrera Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	This talk reviews advances in photocathode technology for accelerators: cathodes demonstrating record average currents and deliverable charge, possessing ultra-low intrinsic emittance and sub-picosecond response time. It addresses the grand challenge to combine all these useful properties into a single photoemitter - one that is being actively pursued by the research community.
	Slides MOZB02 [4.354 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOZB02
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MOPRO001	Upgrade Status of Injector LINAC for SuperKEKB	positron, electron, linac, 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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO001
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MOPRO002	The Momentum Distribution of the Decelerated Drive Beam in CLIC and in the Two-beam Test Stand at CTF3	simulation, operation, distributed, controls	62
	Ch. Borgmann, M. Jacewicz, J. Ögren, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden
	We present analytical calculations of the momentum spectrum of the drive beam in CLIC and the CLIC Test Facility CTF3 after part of its kinetic energy is converted to microwaves for the acceleration of the main beam. The resulting expressions are used to determine parameters of the power conversion process in the Power Extraction Structure (PETS) installed in the Two-beam Test Stand in CTF3.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO002
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MOPRO017	Low Emittance Lattice Cell with Large Dynamic Aperture	sextupole, lattice, dynamic-aperture, storage-ring	99
	A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov BINP SB RAS, Novosibirsk, Russia
	Funding: The work is supported by the Ministry of Education and Science of the Russian Federation. Compact low emittance lattice cell providing large dynamic aperture is essential for development of extremely low (pm range) emittance storage rings. As it is well known, a pair of identical sextupoles connected by a mi-nus-identity matrix transformer in ideal case of kick-like magnets provides infinite dynamic aperture. Though the finite sextupole length degrades the aperture, it is still large enough, and in this report we discuss development of the low emittance cell providing the I condition for both horizontal and vertical chromatic sextupoles.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO017
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MOPRO025	Electron Beam Injection System for SuperKEKB Main Ring	injection, septum, betatron, synchrotron	122
	T. Mori, N. Iida, M. Kikuchi, T. Mimashi, Y. Sakamoto, S. Takasaki, M. Tawada KEK, Ibaraki, Japan
	The SuperKEKB project is in progress toward the initial physics run in the year 2015. It assumes the nano-beam scheme, in which the emittance of the colliding beams is ε=4.6\mbox{nm}. The emittance of the injected beam is ε=1.46\mbox{nm}. To acheave such a low emittance, it is vitally important to preserve the emittance during the transport of the beam from the linac to the main ring. One of the most difficult sections is the injection system. It has been pointed out that the injected beam has possibility of leading to blowup in the ring, which is caused by a beam-beam interaction with the stored positron beam. To avoid the beam blowup, the synchrotron injection is adopted as a backup option. The orbit of the electron injection beam has been designed and the septum magnet prototype has been constructed. The optics study for electron injection and the current R&D status for the septum magnet will be reported in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO025
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MOPRO029	Feed Forward Orbit Correction in the CLIC Ring to Main LINAC Transfer Lines	kicker, extraction, simulation, collimation	131
	R. Apsimon, A. Latina, D. Schulte, J.A. Uythoven CERN, Geneva, Switzerland
	The emittance growth in the betatron collimation system of the 27 km long transfer lines between the CLIC damping rings and the main LINAC depends strongly on the transverse orbit jitter. The resulting stability requirements of the damping ring extraction elements seem extremely difficult to achieve. Position and angle feed forward systems in these long transfer lines bring the specified parameters of the extraction elements within reach. The designs of the optics and feed forward hardware are presented together with tracking simulations of the systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO029
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MOPRO031	Abort Gap Cleaning for LHC Run 2	luminosity, operation, extraction, quadrupole	138
	J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO031
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MOPRO036	Beam Life Time and Stability Studies for ELENA	electron, antiproton, simulation, vacuum	154
	J. Resta-López, O. Karamyshev, D. Newton, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Karamyshev, D. Newton, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom J. Resta-López IFIC, Valencia, Spain
	Funding: Work supported by the EU under Grant Agreement 624854 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1. The Extremely Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which shall be constructed at CERN to decelerate antiprotons to energies as low as 100 keV. At such low energies it is very important to carefully take contributions from electron cooling and heating effects (e.g. on the residual gas) into account. Detailed investigations into the ion kinetics under consideration of effects from electron cooling and scattering on the residual gas have been carried out using the BETACOOL code. In this contribution a consistent explanation of the different physical effects acting on the beam in ELENA is given. Beam lifetime, equilibrium momentum spread and emittance are all estimated based on numerical simulations. Finally, optimum machine settings are presented as a result of optimization studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO036
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MOPRO047	Low Emittance Storage Ring Design for CANDLE project	storage-ring, booster, lattice, dynamic-aperture	188
	G.S. Zanyan, V. Sahakyan, A. Sargsyan, V.M. Tsakanov CANDLE, Yerevan, Armenia
	The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. To improve the CANDLE synchrotron light source performance, a new low emittance facility has been designed with the account of the new developments in magnets fabrication technology of last decade. The lattices for the booster and storage rings are re-designed keeping the geometrical layout of the facilities. The new design provides the beam emittance in storage ring below 5nm with sufficient dynamic aperture. This report presents the main design considerations, the linear and non-linear beam dynamics aspects of the modified facility performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO047
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MOPRO048	Update on Sirius, the New Brazilian Synchrotron Light Source	lattice, insertion, coupling, insertion-device	191
	L. Liu, A.P.B. Lima, N. Milas, A.H.C. Mukai, X.R. Resende, A.R.D. Rodrigues, F. H. de Sá LNLS, Campinas, Brazil
	Sirius is a 3 GeV synchrotron light source that is being built by the Brazilian Synchrotron Light Laboratory (LNLS). The electron storage ring uses the multi-bend-achromat approach (5BA in this case) to achieve a very low beam emittance of 0.28 nm.rad. The 518 m circumference contains 20 straight sections of alternating 6 and 7 meters in length, to be used for insertion devices as well as injection and RF systems. The 5BA cell is modified to accommodate a thin high field dipole (for 1.4˚ deflection) in the center of the middle bend producing hard X-ray radiation (12 keV critical energy) with a modest contribution to the total energy loss. This high field dipole (2.0 T) will be made of permanent magnet material, whereas the low field (0.58 T) ones, responsible for the main beam deflection, will be electromagnetic. Many challenges are associated with this kind of lattice, including both in beam dynamics and in accelerator engineering, that require R&D on new techniques. In this paper we discuss the main issues and achievements for Sirius during the last year.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO048
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MOPRO049	A Low Emittance Lattice Design for the Canadian Light Source	sextupole, quadrupole, lattice, dipole	194
	L.O. Dallin, W.A. Wurtz CLS, Saskatoon, Saskatchewan, Canada
	The CLS presently has a 12 cell DBA lattice with a circumference of 170.88 m. By using conventional magnet designs an emittance of 18 nm-rad is achieved. Twelve 5 m straights are available for injection, an RF cavity and insertion devices. An emittance of 1 nm-rad (at 2.9 GeV) can be achieved replacing each DBAs with multi-bend achromats (MBAs) while preserving the 12-fold symmetry although with a reduction of the length of the straights. To achieve the strong focussing required for low emittance very strong field gradients are required in the dipoles as well as the quadrupole and sextupole magnets. Sufficient dynamic aperture for off-axis injection and Touschek lifetime may be possible.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO049
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MOPRO053	Study of Upgrade Scenarios for the SOLEIL Storage Ring	lattice, optics, dipole, sextupole	203
	R. Nagaoka, P. Brunelle, X.N. Gavaldà, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	Within the scope of a future major upgrade of the SOLEIL storage ring, presently having the energy of 2.75 GeV, the circumference of 354 m and the horizontal emittance of 3.7 nm.rad, towards a Diffraction Limited Storage Ring (DLSR), the present paper presents and discusses the outcomes of a series of studies launched to explore different possible scenarios for the magnet lattice arrangement, under the constraint of making the upgrade in the same existing machine tunnel. Two scenarios were presented earlier in this context, which both preserved all the existing free straight sections for insertions, though the bending magnet positions were not strictly conserved. The purpose of the extended studies is to explore, in particular, the range of horizontal emittance that can be reached by hypothetically removing some of the existing geometric constraints, such as suppressing or shortening partially the straight sections. The emittance range is equally studied by fulfilling rigorously all constraints. The dependence of the nonlinear properties of the magnet lattice on the linear optics is simultaneously investigated.
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MOPRO055	ESRF Upgrade Phase II Status	vacuum, lattice, storage-ring, sextupole	209
	J.-L. Revol, P. Berkvens, J.C. Biasci, J-F. B. Bouteille, N. Carmignani, J. Chavanne, F. Ewald, L. Farvacque, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, G. Le Bec, S.M. Liuzzo, T. Marchial, D. Martin, B. Nash, T.P. Perron, E. Plouviez, P. Raimondi, K.B. Scheidt, V. Serrière, R. Versteegen ESRF, Grenoble, France
	The ESRF is close to the end of the first phase (2009-2015) of its Upgrade Programme and has defined the objectives for the ensuing second phase. It envisions a major upgrade of the source to best serve the new science opportunities. The ESRF Council endorsed the proposal to perform the technical design study of a new 7-bend achromat lattice. This configuration will allow the storage ring to operate with a decrease in horizontal emittance by a factor of about 30 and a consequent increase in brilliance and coherence of the photon beam. This paper reports on the status of the accelerator project, highlighting the progress in the technical design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO055
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MOPRO057	Undulator Photon Beams with Orbital Angular Momentum	undulator, photon, experiment, storage-ring	213
	J. Bahrdt, K. Holldack, P. Kuske, R. Müller, M. Scheer, P.O. Schmid HZB, Berlin, Germany
	Photons carrying orbital angular momentum (OAM) are present in the off-axis radiation of higher harmonics of helical undulators. Usually, the purity and visibility of OAM photons is blurred by electron beam emittance. However, high brightness OAM beams are expected in ultimate storage rings and FELs, and they may trigger a new class of experiments utilizing the variability of the topological charge, a 3rd degree of freedom besides wavelength and polarization. We report on the first detection of OAM photons in helical undulator radiation in the 3rd generation storage ring BESSY II. Measurements and simulations are compared and the impact of emittance and energy spread is discussed.
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MOPRO064	An Ultra-low Emittance Model for the ANKA Synchrotron Radiation Source Including Non-linear Effects	sextupole, lattice, quadrupole, synchrotron	228
	A.I. Papash, A.-S. Müller KIT, Eggenstein-Leopoldshafen, Germany E.B. Levichev, P.A. Piminov, S.V. Sinyatkin, K. Zolotarev BINP SB RAS, Novosibirsk, Russia
	An ultra-low emittance lattice based on the ANKA ring geometry is under investigation in framework of the feasibility studies for a compact low emittance synchrotron light source at the Karlsruhe Institute of Technology (Germany). An attempt to apply the concept of split bending magnets cells and to reduce the natural emittance of the bare ANKA DBA lattice from 90 nm×rad down to 2.5 nm×rad with not-vanishing dynamic aperture is described in this paper. The TME cell with split bends and a quadrupole lens in-between as well as a pair of non-interleaved sextupole lenses separated by “I ” unit transfer matrix of betatron oscillations allows to decrease the theoretical minimum emittance of ANKA ring down to approximately 6 nm×rad. Further reduction of the phase space volume requires to brake “I ” symmetry and add extra families of sextupoles, locate an additional high order field elements inside the quadrupoles, optimize the phase advance between sextupole families, shift the betatron tune point, enlarge the sextupole strength and other measures. Results of simulations are reported.
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MOPRO074	Super Bright Lattice for the Iranian Light Source Facility Storage Ring	lattice, dipole, storage-ring, radiation	255
	H. Ghasem IPM, Tehran, Iran E. Ahmadi ILSF, Tehran, Iran
	To have a competitive leading position in the future and to obtain ultra low beam emittance, save energy and minimizing operation cost, we have designed lattice based on the 5 low field dipole magnets per cell for the storage ring of Iranian light Source Facility (ILSF). The designed lattice has the capability of both soft and hard x-ray radiation from central dipoles. In this paper, we give specifications of lattice linear and nonlinear optimization and review properties of the radiated x-ray.
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MOPRO075	Evolution of Elettra towards an Ultimate Light Source	dipole, lattice, quadrupole, photon	258
	E. Karantzoulis Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Considerations of possible lattices aiming to transform Elettra into an Ultimate Light Source (ULS), the best solution found and some considerations regarding the accelerator components are presented and discussed
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MOPRO076	Elettra Status and Upgrades	operation, controls, coupling, dipole	261
	E. Karantzoulis, A. Carniel, S. Krecic Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the latest studies and upgrades.
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MOPRO077	Betatron Coupling Numerical Study at Elettra	coupling, betatron, quadrupole, lattice	264
	S. Di Mitri, E. Karantzoulis Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	Elettra lacks skew quadrupoles and the coupling is controlled via the vertical orbit. Elettra has typical operational coupling of 1%, values as low as 0.3% were reached but however not easily established and reproducible. In order to control the coupling in a reproducible manner skew quadrupoles must be installed. Simulations of the betatron coupling and correction for the Elettra synchrotron light source were performed and are here presented. The numerical study is based on measured machine misalignments and carried out with the ELEGANT particle tracking code. The inclusion of families of skew quadrupoles in the existing lattice is investigated and shown to be conclusive for the coupling correction at the level of 0.1%.
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MOPRO078	The SPARC_LAB Thomson Source Commissioning	electron, laser, photon, linac	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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MOPRO079	Design of Ultra-low Emittance Ring with Multi-bend Lattice on a Torus-knot	lattice, quadrupole, sextupole, insertion	271
	A. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	We proposed a torus knot type synchrotron radiation ring in that the beam orbit does not close in one turn but closes after multiple turns around the ring. Currently, we are designing a new ring based on the shape of a (11, 3) torus knot for our future plan ‘HiSOR-II.’ This ring is mid-low energy light source ring with a beam energy of 700 MeV. Recently some light source rings are achieving very low emittance that reaches a diffraction limited light by adopting a multi-bend scheme to the arc section of the ring. It is not difficult for low-mid energy VUV-SX light source ring because the electron beam less than 10 nmrad can provide the diffraction limited light in the energy less than 10eV. However the multi-bend lattice has many families of the magnets, therefore it is not easy to decide the parameters of the lattice. Especially, it is difficult for the torus knot type SR ring because there is a lot of geometric limitation around the cross points of orbits. We present the details of the designing procedure and the specifications of the ultra-low emittance light source ring having innovatively odd shape.
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MOPRO081	Resonance Frequency Feedback System for a Precise Magnet Alignment using Multi-vibrating Wires	feedback, resonance, quadrupole, alignment	277
	K. Fukami, N. Azumi, T. Fujita, T. Honiden, H. Kimura, T. Nakanishi, Y. Okayasu, C. Zhang JASRI/SPring-8, Hyogo-ken, Japan K. Kajimoto, T. Watanabe SES, Hyogo-pref., Japan S. Matsui RIKEN/SPring-8, Hyogo, Japan
	An ultimate storage ring (USR) is being designed at synchrotron radiation facilities in the world. USR can generate theoretically minimum synchrotron radiation because emittance of the USR is less than diffraction limit of the radiation. The USR requires high alignment precision of micro-meter order. A vibrating wire method (VWM) has widely been used for such a high precision alignment. An error field of multi-pole magnet is estimated by detecting a vibration of a single wire excited with AC current. The wire position, where no vibration is excited, is defined as the magnetic center. The applied frequency is kept on a resonant frequency, which may drift due to temperature change etc. during the measurement. To trace the resonant frequency at all times, we developed a frequency feedback system. It is necessary to trace the resonance, even when the wire is set in the vicinity of the magnetic center where the magnetic field is nearly zero. Here we propose to install one or two additional wires parallel to the original wire. The additional wires off the center can detect the vibration frequency with enough S/N ratio. We discuss the effectiveness of it for quick and reliable alignment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRO081
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MOPRO083	Design Study of High Brilliant Optics at the SPring-8 Storage Ring	photon, brilliance, optics, electron	283
	Y. Shimosaki, T. Aoki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, H. Ohkuma, M. Shoji, K. Soutome, S. Takano, M. Takao JASRI/SPring-8, Hyogo-ken, Japan
	At the SPring-8 storage ring, design study of beam optics concentrating particularly on increasing brilliance, not flux density, is in progress besides continuous efforts of increasing both brilliance and flux density for the user optics. The natural emittances are theoretically reduced from 2.41 nmrad at 8 GeV to 2.27 nmrad (8 GeV), 1.78 nmrad (7 GeV) and 1.33 nmrad (6 GeV) by utilizing an emittance damping effect by the insertion devices. The designed optics has experimentally been examined at 6 GeV, and the electron beam parameters have been confirmed by measurements at the diagnostics beamlines. * Y. Shimosaki et al., “New Optics with Emittance Reduction at the SPring-8 Storage Ring”, IPAC13, MOPEA027.
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MOPRO091	Fundamental Limits of Velocity Bunching of High-brightness Electron Beams	bunching, electron, cavity, gun	304
	A. Opanasenko, V.V. Mytrochenko NSC/KIPT, Kharkov, Ukraine V.A. Goryashko, V. Zhaunerchyk Uppsala University, Uppsala, Sweden P.M. Salen FYSIKUM, AlbaNova, Stockholm University, Stockholm, Sweden
	The interest in superradiant THz sources based on the coherent transition, synchrotron or undulator radiation grows continuously and such sources require high-quality electron bunches with low emittance, high charge and sub-picosecond (sub-ps) duration. Since accelerator-based THz sources are usually driven by relatively low energy electron bunches of a few tens of MeV, space-charge makes bunch compression to sub-ps level very challenging. In the present work we investigate the feasibility of ballistic bunching down to sub-ps duration while preserving the transverse phase-space quality. We found that in order to compensate for the nonlinear dependency of the arrival time on the energy as well as bunch deformations induced by space-charge effects, one needs to apply a nonlinear energy chirp. This chirp permits to maximize the bunch compression and can be realized by exciting a cavity with higher harmonics of the fundamental frequency. Issues related to synchronizing the harmonics are discussed and the analytical analysis is complemented by simulations with PARMELA.
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MOPRO094	TPS Commissioning Exercise Performed on the TLS	injection, storage-ring, quadrupole, lattice	307
	F.H. Tseng, H.-P. Chang, M.-S. Chiu, S.J. Huang NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) commissioning exercise by using the high-level accelerator physics application programs (HL-APAP) has been performed on the operational 1.5 GeV Taiwan Light Source (TLS) storage ring. It includes steering the injection beam in the first turn to achieve multi-turns and stored beam with the help of the RESOLVE analysis. The orbit correction programs using different algorithms such as SVD, Householder transformation, and local bumps were applied to reduce the closed orbit distortion of the stored beam and to adjust the beam orbit to pass through those field centers of quadrupoles indicated by the corresponding BPMs. The golden orbit defined by the measured data of BPMs corresponding to each quadrupole field center was based on the Beam Based Alignment (BBA). After approach the stored beam orbit to the golden orbit, we save all the BPMs data as the target orbit for machine operation. The lattice calibration is then performed by the LOCO. The detail of the commissioning exercise is described in this report.
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MOPRO097	Status of the Turkish Synchrotron Radiation Source Machine Design	radiation, storage-ring, synchrotron, synchrotron-radiation	313
	Z. Nergiz, H. Aksakal Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey A.A. Aksoy, C. Kaya Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey Ö.K. Öztürk Dogus University, Istanbul, Turkey
	Funding: Work is supported by Ministry of Development of Turkey with Grand No: DPT2006K-120470 Turkish synchrotron radiation source named TURKAY, is a part of the TAC (Turkish Accelerator Center) Project , is at conceptual design process. The radiation properties of a SR sources are strongly depends on the magnetic lattice of the storage ring. The storage ring is designed to obtain low emittance electron beam at 3 GeV energy. Optimization of the lattice properties, including the non-linear dynamics, is described in detail. Radiation properties are calculated by the example of some existing undulators from the other SR facilities.
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MOPRO098	Compact Electron Storage Ring Concepts for EUV and Soft X-ray Production	storage-ring, damping, wiggler, dipole	316
	H.L. Owen, S.A. Geaney, M. Kenyon UMAN, Manchester, United Kingdom J.K. Jones, D.J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Funded in part by the Science and Technology Facilities Council We discuss the use of two novel techniques to deliver low emittance from a compact electron ring at energies around 1 GeV, suitable for EUV and soft X-ray synchrotron radiation production. The first method is the circulation of non-equilibrium electron bunches, which is made feasible using high repetition rate linacs and very fast bunch-by-bunch injection and extraction. The second method is to utilise a stacked storage ring in which two rings are coupled, and in which the strong damping wigglers in one ring depress the emittance in the other. We present example designs of each approach, noting that these methods may be used in combination with other emittance reduction techniques.
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MOPRO099	Long-term Stability of the Diamond Light Source Storage Ring	survey, storage-ring, alignment, insertion	319
	M. Apollonio, K.A.R. Baker, R. Bartolini, W.J. Hoffman, J. Kay, V.C. Kempson, I.P.S. Martin DLS, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	The Diamond Storage Ring (SR) has been in operation since January 2007. This paper summarises a number of measurements that have been made over that period to monitor the SR stability in height and position including general survey, Hydrostatic Levelling System (HLS), horizontal and vertical magnet corrector strengths as well as Radio Frequency (RF) measurements that have given an indication of changing circumference.
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MOPRO104	Low-Energy Intrabeam Scattering Measurements at the Spear3 Storage Ring	storage-ring, damping, radiation, lattice	334
	K. Tian, W.J. Corbett, X. Huang, J.A. Safranek SLAC, Menlo Park, California, USA
	Intrabeam scattering (IBS) can cause emittance growth in diffraction limited light sources. At lower beam energy, the IBS effect is expected to be more pronounced. To study these effects we have developed a series of low energy lattices in SPEAR3 with beam energy ranging from 3GeV to 700MeV. The horizontal beam size and bunch length are measured as a function of beam energy and compared with theoretic calculations.
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MOPRO105	Study of Ultra-low Emittance Design for SPEAR3	dipole, sextupole, quadrupole, electron	337
	M.-H. Wang, R.O. Hettel, X. Huang, T. Rabedeau, J.A. Safranek, K. Tian SLAC, Menlo Park, California, USA
	Funding: Work supported by the US Department of Energy under contract number: DE-AC02-76SF00515 Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, small alpha and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now to further enhance the operation of SPEAR3, we are looking into the possibility of converting SPEAR3 to a multi-bend achromat storage ring within its site constraint.
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MOPRO107	Multi-turn ERL-based Synchrotron Light Facility: Injector Design	gun, linac, 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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MOPME008	3d Full Electromagnetic Beam Dynamics Simulations of the Pitz Photoinjector	simulation, laser, cathode, gun	391
	Y. Chen, E. Gjonaj, W.F.O. Müller, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: work supported by DESY, Hamburg and Zeuthen sites The electromagnetic (EM) simulation software CST STUDIO SUITE® * has been applied to investigate the beam dynamics for the electron gun of the Photo Injector Test facility at DESY, Zeuthen site (PITZ). A series of 3D beam dynamics simulations are performed to study the bunch injection process at PITZ with the objective of clarifying the discrepancies between measurements and simulations. Multiple comparisons are presented for the transverse emittance and the total emitted charge between the measurement data and simulation results using CST STUDIO SUITE®and Astra *. Computer Simulation Technology AG, website: http://www.cst.com/ ** K. Floettmann A Space Charge Tracking Algorithm, user manual (version 3), 2011
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MOPME032	PIC Simulations in Low Energy Part of PIP-II Proton Linac	rfq, simulation, linac, 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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MOPME037	The Development of Stochastic Processes in COSY Infinity	scattering, simulation, lattice, controls	457
	J.D. Kunz IIT, Chicago, Illinois, USA M. Berz, K. Makino MSU, East Lansing, Michigan, USA P. Snopok Illinois Institute of Technology, Chicago, Illlinois, USA
	Funding: Work supported by U.S. Department of Energy. COSY Infinity is an arbitrary-order beam dynamics simulation code. It can determine high-order transfer maps of combinations of particle optical elements. New features are being developed for inclusion in COSY to follow the distribution of particles through matter. To study in detail the properties of muons passing through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte-Carlo approach in which transfer map methods describe the average behavior of the particles including energy loss, and Monte-Carlo methods are used to provide small corrections to the predictions of the transfer map accounting for the stochastic nature of scattering and straggling of particles. The advantage of the new approach is that the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed will aid the optimization of muon cooling channels. Progress on the development of the required algorithms is reported.
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MOPME038	Space Charge Simulation in COSY using The Fast Multipole Method	space-charge, multipole, simulation, collider	460
	B.T. Loseth, M. Berz, K. Makino MSU, East Lansing, Michigan, USA P. Snopok Fermilab, Batavia, Illinois, USA H. Zhang JLab, Newport News, Virginia, USA
	A method is implemented in COSY Infinity that allows the computation of space charge effects of arbitrary and large distributions of particles in an efficient and accurate way based on a variant of the Fast Multipole Method (FMM). It relies on an automatic multigrid-based decomposition of charges in near and far regions and the use of high-order differential algebra methods to obtain decompositions of far fields that lead to an error that scales with a high power of the order. Given an ensemble of N particles, the method allows the computation of the self-fields of all particles on each other with a computational expense that scales as O(N). Furthermore, the method allows the computation of all high-order multipoles of the space charge fields that are necessary for the computation of high-order transfer maps and all resulting aberrations. Space charge effects are crucial in modeling the latter stages of the six-dimensional (6D) cooling channel for the Muon Collider. Results of simulating the 6D cooling channel for the Muon Collider using the FMM method and other tools and improvements implemented for ionization cooling lattices are presented.
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MOPME048	CLIC Decelerator - Machine Protection	quadrupole, alignment, operation, collider	482
	L.M. Hein, J. Esberg, M. Jonker CERN, Geneva, Switzerland
	The Compact Linear Collider CLIC is based on a four beam scheme, two colliding beams (main beams) and two drive beams, which are used to accelerate the main beams. The intended drive beam parameters exceed the "safe beam" threshold by a factor of 100. Hence, in case of a beam impact serious structural damages of the accelerator equipment are expected. In order to avoid structural damages caused by the drive beam detailed studies of its beam dynamics are on-going. In this paper the major characteristics of the drive-beam beam-dynamics and preliminary machine protection results are summarised.
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MOPME049	Design Considerations of the Final Turnaround Regions for the CLIC Drive Beam	lattice, extraction, kicker, dipole	485
	R. Apsimon, J. Esberg, A. Latina, D. Schulte, J.A. Uythoven CERN, Geneva, Switzerland
	The optics design of the final turnaround regions for the CLIC drive beam is presented. This includes the extraction region, the turnaround loop and the phase feed forward chicane for correcting errors on the bunch phase. The design specifications of the kicker and septum magnets are provided. Tracking simulations and detailed studies of coherent and incoherent synchrotron radiation have been used to optimise the optics in the turnaround region in order to minimise transverse and longitudinal emittance growth.
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MOPME084	Proposal for a Soft X-ray Diffraction Limited Upgrade of the ALS	lattice, insertion, insertion-device, injection	567
	C. Steier, A. Anders, D. Arbelaez, K.M. Baptiste, W. Barry, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, R.W. Falcone, J.-Y. Jung, S.D. Kevan, S. Kwiatkowski, T.H. Luo, A. Madur, H. Nishimura, J.R. Osborn, G.C. Pappas, L.R. Reginato, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, H. Tarawneh, W.L. Waldron, W. Wan LBNL, Berkeley, California, USA
	Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Advanced Light Source (ALS) at Berkeley Lab has been updated many times and remains as one of the brightest sources for soft x-rays worldwide. However, recent developments in technology, accelerator physics and simulation techniques open the door to much larger future brightness improvements. Similar to proposals at several other 3rd generation sources, this could be achieved by reducing the horizontal emittance with a new ring based on a multi-bend achromat lattice, reusing the existing tunnel, as well as much of the infrastructure and beamlines. After studying candidate lattice designs, development efforts in the last year have concentrated on technology and physics challenges in four main areas: Injection, Vacuum Systems, Magnets and Insertion Devices, as well as main and harmonic RF systems.
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MOPRI007	Design and Simulation of a High Intensity Muon Beam Production for Neutrino Experiments.	target, proton, solenoid, factory	589
	H. K. Sayed, H.G. Kirk, R.B. Palmer, D. Stratakis BNL, Upton, Long Island, New York, USA K.T. McDonald PU, Princeton, New Jersey, USA D.V. Neuffer Fermilab, Batavia, Illinois, USA
	The production process of pions which then decay into muons, yields a muon beam with large transverse and longitudinal emittances. Such beam requires phase space manipulation to reduce the total 6D emittance before it could go through any acceleration stage. The design of the muon beam manipulation is based on Neutrino Factory front end design. In this study we report on a multi objective - multivariable global optimization of the front end using parallel genetic algorithm. The parallel optimization algorithm and the optimization strategy will be discussed and the optimized results will be presented as well.
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MOPRI012	High Current Low Emittance Proton And Deuteron Beam Production at SMIS 37	plasma, ion, extraction, proton	604
	I. Izotov, S. Golubev, S. Razin, V. Sidorov, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia T. Kalvas, H. A. Koivisto, O.A. Tarvainen JYFL, Jyväskylä, Finland
	This work presents the latest results of high current proton and deuteron beam production at SMIS 37 facility at the Institute of Applied Physics (IAP RAS). This facility creates and heats up the plasma by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap meeting the ECR condition. High microwave power and frequency allow sustaining plasma of significantly higher density (Ne up to 2·10¹³ cm^-3) in comparison to conventional ECRISes or other microwave ion sources. The low ion temperature, on the order of a few eV, is beneficial to produce ion beams with low emittance. Latest experiments at SMIS 37 were performed using a single-aperture two-electrode extraction system. Various diameters of plasma electrode apertures i.e. 5 mm, 7 mm, 10 mm, were tested yielding proton and deuteron beams with currents up to 500 mA with RMS emittance lower than 0.2 π·mm·mrad at extraction voltages up to 45 kV. The maximum beam current density was measured to be 800 mA/cm². A possibility of further improvement through the development of an advanced extraction system is discussed.
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MOPRI017	Status of AREAL RF Photogun Test Facility	gun, electron, laser, operation	620
	B. Grigoryan, G.A. Amatuni, V.S. Avagyan, H. Avdishyan, H. Davtyan, A.A. Gevorgyan, L.H. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, A. Lorsabyan, M. Manukyan, I.N. Margaryan, N. Martirosyan, T.H. Mkrtchyan, S. Naghdalyan, V.H. Petrosyan, H. Poladyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, V. V. Vardanyan, G.S. Zanyan CANDLE SRI, Yerevan, Armenia T.K. Sargsyan LT-PYRKAL cjsc, Yerevan, Armenia
	Advanced Research Electron Accelerator Laboratory (AREAL) is a 20 MeV laser driven RF linear accelerator which is being constructed in the CANDLE institute. The construction of phase-1 is finished and at present the machine commissioning is in progress. In phase-1 a photocathode RF gun provides a 5 MeV small emittance electron beam with the 100 pC bunch charge and variable electron bunch length from 0.5 to 8 ps. Two main operation modes are foreseen for this phase – single and multibunch regimes to satisfy experimental demands. We report the status of linac, first experience and nearest machine run schedule. The brief review of the facility, main parameters, performance and first results are presented.
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MOPRI018	Influence of Growth Method on K3Sb Photocathode Structure and Performance	cathode, synchrotron, experiment, scattering	624
	S.G. Schubert, T. Kamps, M. Schmeißer HZB, Berlin, Germany K. Attenkofer, J. Smedley BNL, Upton, Long Island, New York, USA E.M. Muller SBU, Stony Brook, New York, USA H.A. Padmore, J.J. Wong LBNL, Berkeley, California, USA M. Ruiz-Osés Stony Brook University, Stony Brook, USA J. Xie ANL, Argonne, Illinois, USA
	Funding: Supported by Director, OoS., OBES of US DOE, Contract DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNTI0013, DE-SC0005713, germ. BMBF, Land Berlin, Helmholtz Assoc.. Use of CHESS by NSF, DMR-0936384. Future high brightness photoelectron sources delivering >100 mA average current call for a new generation of photocathodes. Materials which qualify for this purpose should exhibit low intrinsic emittance, long lifetime and high quantum efficiency at photon energies in the visible range of the spectrum to relax drive laser requirements. A combination of material science techniques are used to determine the influence of the growth parameters on structure and performance of photocathode materials . In-situ XRR, XRD and GiSAXS measurements were performed at the synchrotron radiation sources, NSLS and CHESS. The growth of K3Sb, a precursor material of one of the prime candidates CsK2Sb, was studied intensively to optimize this intermediate growth step in terms of quantum efficiency and roughness. Three methods, a “layer by layer” type and a “super-lattice type” were examined. K3Sb exists in two crystallographic phases, namely cubic and hexagonal. The cubic phase exhibits a higher quantum efficiency at 532 nm than the hexagonal phase and transforms more easily into CsK2Sb, tuning this phase is believed to be one of the key parameters in the CsK2Sb growth.
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MOPRI023	Simulation of the ELBE SRF Gun II	gun, simulation, SRF, laser	636
	P.N. Lu, A. Arnold, U. Lehnert, P. Murcek, J. Teichert, H. Vennekate, R. Xiang HZDR, Dresden, Germany
	Funding: EuCARD, contract number 227579 German Federal Ministry of Education and Research grant 05 ES4BR1/8 LA³NET, Grant Agreement Number GA-ITN-2011-289191 By combining the code of ASTRA and elegant in a user-friendly interface, a simulation tool is developed for the ELBE SRF Gun II. The photoelectric emission and first acceleration to several MeV in the gun cavity are simulated by ASTRA with a 1D Model, where the space charge effect is considered. The dependence of the beam quality on key parameters is studied, and a compromised optimization for a 77 pC beam is used for further elegant simulation of the beam transport through a dogleg and ELBE Linacs. Proper settings of the magnets and RF phases are the main targets of improving the beam quality. Up to now the best simulation result is an electron bunch with the energy of 47 MeV, energy spread of 66 keV, bunch length of 0.35 ps and transverse emittance of 1.9 μm and 2.7 μm in the two perpendicular directions.
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MOPRI032	A STUDY ON ROBUSTNESS OF NEA-GAAS PHOTOCATHODE*	cathode, electron, vacuum, experiment	664
	K. Uchida, R. Kaku, M. Kuriki, K. Miyoshi, Y. Seimiya, N. Yamamoto HU/AdSM, Higashi-Hiroshima, Japan H. Iijima Tokyo University of Science, Tokyo, Japan
	Electron source is one of the most important component in the advanced linac. There is a strong demand on the high performance cathode, such as small emittance, high brightness, and short pulse generation. NEA-GaAs photo-cathode is a unique technology which is capable for generating highly polarized and extremely low emittance beam. Quantum efficiency (QE) of the cathode is high in near IR region, so it is favor to generate a high current density beam. These advantages are originated to the Negative Electron Affinity (NEA) surface, but it is fragile so the operational lifetime is limited. A study on a robust NEA surface cathode is reported. According to the hetero-junction model, Cs-Te thin film deposited on GaAs forms a robust NEA surface. We performed the Cs-Te evaporation experiment on a clean GaAs cathode and measured QE spectra. We found that some sample showed a high quantum efficiency up to 900nm wavelength which strongly suggested a NEA surface formation.
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MOPRI033	Quasi-traveling Wave Side Couple RF Gun Commissioning for SuperKEKB	gun, cavity, cathode, coupling	667
	T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou KEK, Ibaraki, Japan
	We are developing a new RF gun for SuperKEKB. High-charge low-emittance electron and positron beams are required for SuperKEKB. We will generate 7.0 GeV electron beam at 5 nC 20 mm-mrad by J-linac. In this linac, a photo cathode S-band RF gun will be used as the electron beam source. For this reason, we are developing an advanced RF gun. New RF gun which has two side coupled standing wave field is developed. We call it quasi traveling wave side couple RF gun. This gun has a strong focusing field at the cathode and the acceleration field distribution also has a focusing effect. Beam commissioning has been started with the new RF gun. I will report the result of beam commissioning.
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MOPRI035	Development of the Photocathode LiTi2O4 and Evaluations of the Initial Emittance	cathode, laser, electron, cavity	673
	R. Inagaki, M. Hosaka, Y. Takashima, N. Yamamoto Nagoya University, Nagoya, Japan T. Hitosugi, S. Shiraki Tohoku Uneversity, WPI-AIMR, Sendai, Japan E. Kako, Y. Kobayashi, S. Yamaguchi KEK, Ibaraki, Japan M. Katoh, T. Konomi, T. Tokushi UVSOR, Okazaki, Japan Y. Okano IMS, Okazaki, Japan
	In UVSOR, the X-ray free electron laser (XFEL) based on linear accelerator with high pulse repetition about 1MHz has been designed as a candidate for the next radiation sources. We thought a combination of superconducting RF cavity and photocathode is an optimal electron gun for the new accelerator. For this electron gun, we propose a back-illuminated multi-alkali* photocathode with transparent superconductor LiTi2O4*. The reason for using LiTi2O4 is to reflect RF by using feature of penetration depth of superconductor, which is defined from London equation. This feature protects optical components from RF damage. However, LiTi2O4 is a new material and properties are not clear. We have measured the basic properties of this photocathode, such as magnetic susceptibility measurement and photoelectron spectrometry, etc. In this conference, we will explain the detail of the concept and advantage of this cathode, and show the result measured about the basic properties of this photocathode focusing on the initial emittance measurement. A. V. Lyashenko et al. JINST 4 P07005 (2009) ** Kumatani et al. APL 101 (2012) 123103″
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MOPRI040	Design and Analysis of an Electron Beam in an Electron Gun for X-Ray Radiotherapy	electron, gun, cathode, simulation	688
	J.C. Lee, J.-S. Chai, M. Ghergherehchi, H.S. Kim, Y.S. Lee, S. Shin, Y.H. Yeon SKKU, Suwon, Republic of Korea B.N. Lee KAERI, Dae-jeon, Republic of Korea
	Funding: This work was supported by (IT R&D program of MSIP/KEIT [10043897] and MOTIE [13-DU-EE-12]) in KOREA. Electron linear accelerators are used as x-ray generators for diagnosing the human body. In this paper conceptual design of electron beam for compact electron gun was calculated by using EGN2w and CST-Particle Studio codes. The structure of the electron gun was used for Pierce and diode type and the specification of electron beam was selected as 500 cGy/min. Specifications of designed electron gun were focused on current, beam size and normalized emittance. Optimized beam current, diameter and normalized emittance are 226.88 mA, 0.689 mm (Full width) and 1.03π mm• mrad, respectively by using two simulation codes. Accuracy of simulation was verified by comparison of emitted beam current which has error of 0.74%. * Subhash C. Sharma et al., Journal of applied clinical medical physics, 8, 3 (2007) 119-125. * Yuichiro Kamino et al., Med. Phys. 34 (2007) 1797-1808.
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MOPRI043	Study of a C-band Standing-wave Gun for the SwissFEL Injector	gun, cathode, solenoid, coupling	698
	M. Schaer, S. Bettoni, A. Citterio, P. Craievich, M. Negrazus, L. Stingelin, R. Zennaro PSI, Villigen PSI, Switzerland
	The baseline design of the SwissFEL injector foresees the "PSI Gun 1", a 2.6-cell RF photo-cathode gun operating at S-band frequency, as the electron source. In this paper a new design is presented where a 5.6-cell C-band gun could replace the PSI Gun 1 with no impact on the rest of the injector setup. A conservative maximum gradient of 135 MV/m at the cathode is assumed which drives the electron beam faster into the relativistic regime and therefore allows to tolerate larger charge densities. The presented solution also foresees a coaxial RF coupling from the cathode side in order to place the gun solenoid as near to the photo-cathode as possible, improving the emittance compensation. Astra simulations showed that the transverse beam brightness can be doubled before the first bunch compressor preserving the low transverse emittance value as compared to the current design for the S-band injector configuration of SwissFEL.
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MOPRI044	Feasibility Study of an Ultrafast Electron Diffraction System in NSRRC	electron, gun, injection, cathode	701
	P. Wang, K.C. Leou NTHU, Hsinchu, Taiwan N.Y. Huang, W.K. Lau, A.P. Lee NSRRC, Hsinchu, Taiwan
	It has been suggested that the MeV beam generated from a laser-driven photo-cathode rf gun can be used for ultrafast electron diffraction (UED). The feasibility of operating the NSRRC photo-cathode rf gun system for ultrashort bunch generation is being investigated. The results of space-charge tracking calculations show that a low emittance, few hundred femtoseconds MeV beam with reasonable bunch charge can be generated for single shot UED experiments. In this report, a preliminary design of this UED system will be discussed. X.J. Wang et al., in Proceedings of PAC'03, p.420.
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MOPRI045	Beam Diagnostics E-GUN Test Stand at TARLA	gun, electron, radiation, cathode	704
	Ç. Kaya, A.A. Aksoy, A. Aydin, V. Karakilic, Ö. Karslı, E. Kazancı, B. Koc, S. Kuday, E.Ç. Polat, I. Sara, M. Yildiz Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey S. Özkorucuklu Istanbul University, Istanbul, Turkey
	Funding: Work supported by Turkish State Planning Organization (Grant No: DPT2006K-120470) Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) facility, which is essentially proposed to generate oscillator mode FEL in 3-250 microns wavelengths range, will consist of totally normal conducting injector system with 250 keV beam energy, two superconducting RF accelerating modules in order to accelerate the beam 15-40 MeV. Continuous wave (CW) electron beam will provided by TARLA thermionic electron gun (E-GUN). Various aspects of the Thermionic EGUN test stand to deliver the necessary electron beam in terms of bunch charge, current, energy, emittance and profile for the beam diagnostic will be discussed. Primarily measurements results of electron beam energy loss and transverse orbit will be shown as well as beam image and shape measurements. On behalf of TARLA Collaboration
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MOPRI049	An Ultracold Electron Facility in Manchester	electron, laser, space-charge, extraction	714
	Ö. Mete, R. Appleby, W. Bertsche, M.A. Harvey, G.X. Xia UMAN, Manchester, United Kingdom S. Chattopadhyay Cockcroft Institute, Warrington, Cheshire, United Kingdom A.J. Murray The University of Manchester, The Photon Science Institute, Manchester, United Kingdom
	An ultra-cold atom based electron source (UCAE) facility has been built in the Photon Science Institute (PSI), University of Manchester. In this paper, the key components and working principles of this source are introduced. Pre-commissioning status of this facility and the preliminary simulations results are presented.
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MOPRI050	Preliminary Study for an RF Photocathode based Electron Injector for AWAKE Project	laser, electron, focusing, plasma	717
	Ö. Mete, G.X. Xia UMAN, Manchester, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Chattopadhyay Cockcroft Institute, Warrington, Cheshire, United Kingdom
	AWAKE project, a proton driven plasma wakefield acceleration (PDPWA) experiment is approved by CERN. The PDPWA scheme consists of a seeding laser, a drive beam to establish the accelerating wakefields within the plasma cell; and a witness beam to be accelerated. The drive beam protons will be provided by the CERN's SPS. The plasma ionisation will be performed by a seeding laser and the drive beam protons to produce the accelerating wakefields. After establishing the wakefields, witness beam, namely, electron beam from a dedicated source should be injected into the plasma cell. The primary goal of this experiment is to demonstrate acceleration of a 5-15 MeV single bunch electron beam up to 1 GeV in a 10 m of plasma. This paper explores the possibility of an RF photocathode as the electron source for this PDPWA scheme based on the existing PHIN photoinjector at CERN. The modifications to the existing design, preliminary beam dynamics simulations in order to provide the required electron beam are presented in this paper.
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MOPRI053	High Repetition Rate Ultrafast Electron Diffraction at LBNL	electron, gun, experiment, laser	724
	D. Filippetto, M. Mellado Munoz, H.J. Qian, F. Sannibale, W. Wan, R.P. Wells, M.S. Zolotorev LBNL, Berkeley, California, USA
	Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231" Here we propose to use the APEX photo-gun as novel source for time-resolved electron diffraction studies. The electron source has been designed, built and successfully tested at LBNL. It combines a high accelerating field needed for bright beams, MeV electron energy essential for time resolution in gas-phase experiments and studies of bulk processes, together with continuous (CW) operations. Ultra-short electron pulses can be delivered with a maximum repetition rate of 186 MHz, enabling new science to be studied. We report the design of a dedicated electron diffraction beamline that fits in the space constraints of the APEX tunnel. Simulations of beam properties have been carried out with a genetic optimizer, showing 100 fs time resolution. Beam jitters in energy, time and position are currently being characterized, and a mitigation strategy via fast feedback loops is discussed.
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MOPRI055	APEX Present Experimental Results	cathode, gun, electron, laser	730
	D. Filippetto, C.W. Cork, S. De Santis, L.R. Doolittle, G. Huang, R. Huang, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, F. Sannibale, J.W. Staples, R.P. Wells LBNL, Berkeley, California, USA J. Yang TUB, Beijing, 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 APEX electron source at LBNL combines high-repetition-rate and high beam brightness typical of photo-guns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment. It would enable high repetition rate operations for brightness-hungry applications such as X-Ray FELs, and MHz ultrafast electron diffraction. A full 6D characterization of the beam phase space at the gun beam energy (750 keV) is foreseen in the first phase of the project. Diagnostics for low and high current measurements have been installed and tested, measuring the performances of different cathode materials in a RF environment with mA average current. A double-slit system allows the characterization of beam emittance at high charge and full current (mA). An rf deflecting cavity and a high precision spectrometer allow the characterization of the longitudinal phase space. Here we present the latest results at low and high repetition rate, discussing the tools and techniques used.
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MOPRI058	Metal Plasmonic Nanostructures Functionalized by Atomic Layer Deposition of MgO for Photocathode Applications	electron, cathode, vacuum, resonance	739
	S.V. Baryshev, S.P. Antipov, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA M.R. Savina, A.V. Zinovev ANL, Argonne, Illinois, USA E. Thimsen University of Minnesota, Minneapolis, USA
	Funding: Euclid TechLabs LLC acknowledges support from the DOE SBIR program, grant No. DE-SC0009572. To create high current, long lasting electron sources capable of providing sub-ps bunches, new photocathode concepts are sought. Most recently, plasmonic nanostructured metal surfaces or flat metal surfaces activated by an ultrathin MgO are under great attention. We report on a photocathode design combining these two approaches. It consists of plasmonic Ag nanoparticles (NPs) functionalized by 3 MgO monolayers (MLs). Ag NPs were synthesized by an aerosol method and MgO was grown by atomic layer deposition (ALD). The NPs geometry was tuned to obtain broadband >50% absorption in the entire blue range as evidenced by UV-vis. spectroscopy. The WF of 3 MgO MLs/Ag NPs multilayer was reduced by 1 eV compared to bare NPs, from 5 to 4 eV, as evidenced by UPS and Kelvin probe. Reduction by 1 eV is maximal for this pair of materials, and agrees well with experimental and theoretical findings. While the effect on WF is indeed significant, a special handling protocol for Ag before depositing MgO is a must. It would preserve a clean Ag surface with a WF of nearly 4 eV to achieve 3 eV upon ALD of MgO. This and other issues are under study to promote photocathode applications.
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MOPRI084	Beam Dynamic into the Transfer RIB Lines to the DESIR Facility at GANIL-SPIRAL2	quadrupole, ion, diagnostics, vacuum	806
	L. Perrot, H. Cherif IPN, Orsay, France
	Funding: French ANR, Investissements d'Avenir, EQUIPEX Contract number ANR-11-EQPX-0012 The new ISOL facility SPIRAL2 is currently being built at GANIL, Caen France. SPIRAL2 will produce a large number of new radioactive ion beams (RIB) at high intensities. The DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation), from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions) and from the SPIRAL2 production cave (n-induced fission of 238U, nucleon transfer and fusion-evaporation reactions). In order to deliver the RIB to the experimental set-ups installed in the DESIR hall, 110 meters of beam line have to be designed, originating from 3 different facilities. This paper will focus on the studies which have been done on these transfer lines: beam optics and errors calculations, quadrupoles, diagnostics and mechanical designs.
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MOPRI086	Status of the PXIE Low Energy Beam Transport Line	solenoid, ion, ion-source, rfq	812
	L.R. Prost, R. Andrews, A.Z. Chen, B.M. Hanna, V.E. Scarpine, A.V. Shemyakin, J. Steimel Fermilab, Batavia, Illinois, USA R.T.P. D'Arcy UCL, London, United Kingdom
	Funding: Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy A CW-compatible, pulsed H⁻ superconducting RF linac (a.k.a. PIP-II) is envisaged as a possible path for upgrading Fermilab’s injection complex [1]. To validate the concept of the front-end of such machine, a test accelerator (a.k.a. PXIE) [2] is under construction. The warm part of this accelerator comprises a 10 mA DC, 30 keV H⁻ ion source, a 2m-long LEBT, a 2.1 MeV CW RFQ, and a MEBT that feeds the first cryomodule. In addition to operating in the nominal CW mode, the LEBT should be able to produce a pulsed beam for both PXIE commissioning and modelling of the front-end nominal operation in the pulsed mode. Concurrently, it needs to provide effective means of inhibiting beam as part of the overall machine protection system. A peculiar feature of the present LEBT design is the capability of using the ~1m-long section immediately preceding the RFQ in two regimes of beam transport dynamics: neutralized and space charge dominated. This paper introduces the PXIE LEBT, reports on the status of the ion source and LEBT installation, and presents the first beam measurements.
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MOPRI094	Proposal for a Slow Extraction System for a Biomedical Research Facility at CERN based on LEIR	extraction, resonance, sextupole, quadrupole	833
	A. Garonna, D. Abler, C. Carli CERN, Geneva, Switzerland
	Funding: This work was partly funded by the Marie Curie Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract number PITN-GA-2008-215840-PARTNER. A proposal has been made to accelerate ion beams ranging from hydrogen to neon with magnetic rigidities up to 6.7 Tm for biomedical experiments at CERN using the Low Energy Ion Ring (LEIR), in parallel to its continued operation for LHC and for SPS fixed target physics experiments. The feasibility of a new slow extraction system for LEIR based on the third integer resonance was studied with two possible resonance driving mechanisms: quadrupole-driven extraction and RF-knockout extraction. The extraction of fully stripped carbon ions (20-440 MeV/u kinetic energies) has been studied in detail. The requirement to keep the present performance of the machine for physics experiments imposes tight space constraints for the upgrade. The extraction scheme and the hardware requirements are described in this paper.
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MOPRI102	Upgrades of the CERN PS Booster Ejection Lines	optics, injection, quadrupole, dipole	858
	W. Bartmann, J.L. Abelleira, K. Hanke, M. Kowalska CERN, Geneva, Switzerland
	The PS Booster extraction energy will be augmented from 1.4 to 2 GeV to reduce intensity limits due to space charge at the PS proton injection. For this upgrade the transfer line between PS Booster and PS will be modified for 2 GeV operation and pulse to pulse optics modulation for different beam types. Also the PS Booster measurement line will also be upgraded to 2 GeV and shall provide improved optics solutions for emittance measurements while reducing the loss levels recorded during operation. This paper describes the foreseen optics solutions for both transfer lines.
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TUXA01	Commissioning the 400 MeV Linac at J-PARC and High Intensity Operation of the J-PARC RCS	injection, linac, dipole, 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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TUOAA03	Extra Low ENergy Antiproton ring ELENA: From the Conception to the Implementation Phase	experiment, antiproton, electron, extraction	910
	C. Carli, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, T. Eriksson, S. Maury, S. Pasinelli, G. Tranquille CERN, Geneva, Switzerland W. Oelert Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany
	The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a small 30 m circumference synchrotron to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. The ELENA design is now well advanced and the project is moving to the implementation phase. Component design and construction are taking place at present for installation foreseen during the second half of 2015 and beginning of 2016 followed by ring commissioning until the end of 2016. New electrostatic transfer lines to the experiments will be installed and commissioned during the first half of 2017 followed by the first physics operation with ELENA. Basic limitations like Intra Beam Scattering limiting the emittances obtained under electron cooling and direct space charge effects will be reviewed and the status of the project will be reported.
	Slides TUOAA03 [4.963 MB]
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TUYA01	First Experience with Electron Lenses for Beam-beam Compensation in RHIC	electron, solenoid, hadron, proton	913
	W. Fischer, Z. Altinbas, D. Bruno, M.R. Costanzo, X. Gu, J. Hock, A.K. Jain, Y. Luo, C. Mi, R.J. Michnoff, T.A. Miller, A.I. Pikin, T. Samms, Y. Tan, R. Than, P. Thieberger, S.M. White BNL, Upton, Long Island, New York, USA
	Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. The head-on beam-beam interaction is the dominant luminosity limiting effect in polarized proton operation in RHIC. To mitigate this effect two electron lenses were installed in the two RHIC rings. We summarize the hardware and electron beam commissioning results to date, and report on the first experience with the electron-hadron beam interaction. In 2014 RHIC is operating with gold beams only. In this case the luminosity is not limited by head-on beam-beam interactions and compensation is not necessary. The goals of this year’s commissioning efforts are a test of all instrumentation; the demonstration of electron and gold beam overlap; the demonstration of electron beam parameters that are sufficiently stable to have no negative impact on the gold beam lifetime; and the measurement of the tune footprint compression from the beam overlap. With these demonstrations, and a lattice with a phase advance that has a multiple of 180 degrees between the beam-beam interaction and electron lens locations, head-on beam-beam compensation can be commissioned in the following year with proton beams.
	Slides TUYA01 [11.776 MB]
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TUOAB03	Nonlinear Optics for Suppression of Halo Formation in Space Charge Dominated Beams	focusing, quadrupole, space-charge, simulation	953
	Y.K. Batygin, A. Scheinker LANL, Los Alamos, New Mexico, USA C. Li IMP, Lanzhou, People's Republic of China
	Traditional accelerator designs utilize linear focusing elements (quadrupoles, solenoids) to provide stable particle motion. High – intensity rms - matched non - uniform beams are intrinsically mismatched with linear focusing structure. It results in space charge induced beam emittance growth and halo formation, which can be suppressed in a quadrupole channel with higher-order multipole field components. In this paper, overview of FODO quadrupole channels with arbitrary multipoles is given. Effective averaged potential is presented for the structure with periodic combination of multipole lenses and quadrupoles. Density of matched beam avoiding emittance growth and halo formation is derived. Performed analysis allows matching of realistic beam with the internal structure of the focusing field. Beam dynamics studies with suppressed halo are presented and discussed.
	Slides TUOAB03 [3.404 MB]
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TUPRO006	Strong-strong Beam-beam Simulation for the LHC Upgrade	simulation, cavity, resonance, luminosity	1006
	J. Qiang, S. Paret LBNL, Berkeley, California, USA G. Arduini, T. Pieloni CERN, Geneva, Switzerland J. Barranco García EPFL, Lausanne, Switzerland
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 using computing resources at the NERSC. The LHC upgrade will significantly improve the performance of the current LHC operation with higher collision energy and luminosity. In the paper, we report on the progress in the strong-strong beam-beam simulation of the HL-LHC upgrade with crab cavity compensation. We will present the study of the effects of accelerator tune working points, dipole noise, and crab cavity noise on colliding beam emittance growth.
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TUPRO010	Origins of Transverse Emittance Blow-up during the LHC Energy Ramp	luminosity, injection, simulation, brightness	1021
	M. Kuhn, G. Arduini, V. Kain, A. Langner, Y. Papaphilippou, M. Schaumann, R. Tomás CERN, Geneva, Switzerland
	During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.
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TUPRO023	Beam-beam Effects in Different Luminosity Levelling Scenarios for the LHC	luminosity, dynamic-aperture, experiment, beam-beam-effects	1061
	X. Buffat, D. Banfi, G.R. Coombs EPFL, Lausanne, Switzerland W. Herr, T. Pieloni CERN, Geneva, Switzerland
	Adjusting luminosity and optimizing the luminous region in each interaction point of the LHC according to the experiments needs has become a requirement to maximize the efficiency of the different detectors. Several techniques are envisaged, most importantly by varying β* or a transverse offset at the interaction point. Coherent and incoherent stability in the presence of beam-beam effects will be discussed in realistic luminosity levelling scenarios for the LHC.
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TUPRO026	Possible Beam-beam and Levelling Scenarios for HL-LHC	luminosity, simulation, collider, hadron	1071
	M.P. Crouch, R. Appleby UMAN, Manchester, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom T. Pieloni CERN, Geneva, Switzerland
	Funding: Research supported by EU FP7 HiLumi LHC - Grant Agreement 284404 The upgrade of the LHC from the current set-up to high luminosity performances will provide new challenges from the point of view of beam-beam as well as other collective effects and luminosity levelling. We present the current possibilities for doing luminosity levelling for HL-LHC. We explore the merits and drawbacks of each option and briefly discuss the operational implications. The simplest option being levelling with an offset between the two beams. In particular, we look at the possibility of using flat beams in the IPs for all the available options and investigate their benefits and drawbacks, using the code COMBI. Flat beams would allow an additional degree of freedom, with the levelling only required in one of the planes at any given IP. To this end, various scenarios are looked at, both with and without crab cavities.
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TUPRO034	Beam-beam Interaction in the Asymmetric Energy Gold-gold Collision in RHIC	simulation, ion, experiment, collider	1093
	Y. Luo, M. Blaskiewicz, M.R. Costanzo, W. Fischer, X. Gu, V.H. Ranjbar, S.M. White 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 this article, we study the beam-beam interaction in the possible future gold-gold collision with different particle energies in the Relativistic Heavy Ion Collider (RHIC). With different particle energies, the center-of-mass of collision is moving in the longitudinal direction during collision. Since the RF harmonic numbers are different for the two RHIC rings, bunches collide in 110 turns followed by 10 turns without collision. In this study, the stability of particles and the beam emittance growth are calculated through numeric simulations based on a 6-D weak-strong beam-beam interaction model.
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TUPRO035	Vertical Emittance at the Quantum Limit	quadrupole, storage-ring, sextupole, coupling	1096
	R.T. Dowd, Y.E. Tan SLSA, Clayton, Australia K.P. Wootton The University of Melbourne, Melbourne, Victoria, Australia
	Further reduction of betatron coupling and vertical dispersion in the storage ring of the Australian Synchrotron Light Source has resulted in the achievement of a beam vertical emittance that is now dominated by the intrinsic quantum effects. This paper will detail the key elements in achieving a vertical emittance at the quantum limit and results achieved.
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TUPRO036	Start-to-end Optic of the FSF Multi-turn ERL Project	linac, 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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TUPRO037	Suppression Techniques of CSR Induced Emittance Growth in ERL Arcs	electron, simulation, synchrotron, betatron	1102
	A.V. Bondarenko, T. Atkinson, A.N. Matveenko HZB, Berlin, Germany
	The Energy Recovery Linac (ERL) conception is a promising way of creating diffraction limited synchrotron light source. The high ERL beam quality (low emittance, short bunch and low energy spread) gives an opportunity to generate high brightness photon beams. One of the main requirements for the optic in such machines is the suppression of emittance growth. An important reason for beam degradation is the impact of Coherent Synchrotron Radiation (CSR) in bending magnets. CSR induced emittance dilution and methods of preservation both with and without compression are discussed in this article.
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TUPRO038	Beam Positioning Concept and Tolerance Considerations for BERLinPro	laser, linac, 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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TUPRO044	Bunch Compression of the Low-energy ELBE Electron Beam for Super-radiant THz Sources	radiation, electron, linac, 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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TUPRO046	Beamlines with Two Deflecting Cavities for Transverse-to-Longitudinal Phase Space Exchange	quadrupole, cavity, beam-transport, controls	1129
	V. Balandin, W. Decking, N. Golubeva DESY, Hamburg, Germany
	Optical systems for transverse-to-longitudinal emittance exchange involving single dipole-mode cavity were in great details studied during the last decade theoretically and experimentally. In this paper we discuss the question, if there are any advantages in usage of beamlines utilizing two deflecting cavities instead of one. The general analysis is presented and specific beamline designs are given as examples.
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TUPRO048	Dynamics of Twiss Parameters from the Geometrical Viewpoint	framework, betatron, survey	1135
	V. Balandin, N. Golubeva DESY, Hamburg, Germany
	We show that with an appropriate parametrization the linear transport of the Twiss parameters can be viewed as a bilinear (or Moebius) map of the upper complex half-plane (which is the hyperbolic plane) into itself. Using then elementary techniques of hyperbolic geometry we classify transformations of the Twiss parameters into elliptic, hyperbolic and parabolic types and, for each type, present its typical phase space portraits.
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TUPRO051	Emittance Increase and Matching along the Tomography Module at PITZ	focusing, quadrupole, electron, lattice	1144
	G. Kourkafas, P. Boonpornprasert, J.D. Good, M. Groß, I.I. Isaev, D.K. Kalantaryan, M. Khojoyan, M. Krasilnikov, D. Malyutin, B. Marchetti, D. Melkumyan, M. Otevřel, T. Rublack, F. Stephan, G. Vashchenko DESY Zeuthen, Zeuthen, Germany G. Asova INRNE, Sofia, Bulgaria G. Pathak Uni HH, Hamburg, Germany
	The Photo Injector Test facility at DESY, Zeuthen site (PITZ), focuses on testing, characterizing and optimizing high brightness electron sources for free electron lasers. PITZ is equipped with a number of transverse emittance measurement stations, among which is the Phase Space Tomography (PST) module. A PST measurement requires a specific transport along the tomography lattice, which ideally rotates the beam in the normalized transverse phase space by 180 degrees in equidistant steps. A preceding matching section is used to provide an injection scheme that delivers the necessary beam parameters for the design transport along the tomography lattice. The high charge density and moderate energy of the electron bunch at PITZ contribute to significant space-charge forces which lead to emittance growth and consequent mismatches of the design parameters. This article presents and evaluates measurements of the emittance increase along the matching section of a 1 nC beam at 22 MeV/c under different focusing schemes.
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TUPRO052	Study a ‘Sum’ Linear Coupling Resonance for J-PARC Main Ring: Observations and Simulations	resonance, operation, injection, coupling	1147
	A.Y. Molodozhentsev, S. Igarashi KEK, Ibaraki, Japan Y. Sato, J. Takano J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	J-PARC Main Ring should deliver a high-power proton beam to neutrino experiments with limited particle losses. To meet this requirement low-order machine resonances have to be compensated. The linear coupling resonance Qx+Qy=43 has been identified as the potential source for significant particle losses at the collimator. The resonance compensation scheme has been studied experimentally by using a low intensity beam. To understand this process the simulations have been performed by using the PTC-ORBIT code. The Main Ring model has been developed to reproduce the machine operation including the initial stage of the acceleration. The 6D beam model has been defined to represent the ‘pencil’ beam used for this study. In frame of this report the single and multi particle dynamics will be discussed to understand the results of measurements, performed during RUN44 (November 2012). The results of the long-term tracking for this case will be presented. The obtained results can be used to benchmark the computer modeling the ‘sum’ linear coupling resonance with the experimental results.
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TUPRO056	Merit Functions for the Linac Optics Design for Colliders and Light Sources	optics, focusing, linac, 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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TUPRO064	Scaling Laws of Wake Field Effects for Gradient Changes in the CLIC Main Linac	linac, wakefield, 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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Paper

Title

Other Keywords

Page

MOXBA01

Challenges in the Design of Diffraction-limited Storage Rings

lattice, photon, brightness, storage-ring

7

R.O. Hettel
SLAC, Menlo Park, California, USA

This presentation reviews current developments in the design of ultra-low emittance lattices, the experience and challenges with the operation of low emittance lattices and the main technological problems. Beam dynamics issues and collective effects for ultra low emittance machines are also addressed.

Slides MOXBA01 [6.969 MB]

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MOYBA02

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

cryomodule, linac, cavity, klystron

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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MOOCA03

Design of High-power Graphene Beam Window

scattering, proton, target, Windows

45

H.J. Wang, H.T. Jing, H. Qu, J.Y. Tang
IHEP, Beijing, People's Republic of China

Beam window is a key device in high-intensity hadron beam applications, and it is usually used to separate air or other gas environments in the end of beam vacuum duct. Compared with the usually-used window materials such as Inconel alloy, Aluminum alloy and so on, the graphene has extremely high thermal conductivity, high strength and high transparency to high-energy ions. With the maturation of large-size graphene manufacturing technology, we have studied this new-type window for MW-class proton beam. The thermal analyses by the theoretical formula and simulations based on FEA are presented in this paper. Simultaneously, the scattering effect and the lifetime are also discussed. The preliminary results are promising. The same material can also be possibly applied to other devices such as charge-exchange stripping foils, beam monitors and so on.

Slides MOOCA03 [1.467 MB]

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MOZB02

Advances in Photocathodes for Accelerators

electron, cathode, laser, experiment

48

L. Cultrera
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

This talk reviews advances in photocathode technology for accelerators: cathodes demonstrating record average currents and deliverable charge, possessing ultra-low intrinsic emittance and sub-picosecond response time. It addresses the grand challenge to combine all these useful properties into a single photoemitter - one that is being actively pursued by the research community.

Slides MOZB02 [4.354 MB]

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MOPRO001

Upgrade Status of Injector LINAC for SuperKEKB

positron, electron, linac, 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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MOPRO002

The Momentum Distribution of the Decelerated Drive Beam in CLIC and in the Two-beam Test Stand at CTF3

simulation, operation, distributed, controls

62

Ch. Borgmann, M. Jacewicz, J. Ögren, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

We present analytical calculations of the momentum spectrum of the drive beam in CLIC and the CLIC Test Facility CTF3 after part of its kinetic energy is converted to microwaves for the acceleration of the main beam. The resulting expressions are used to determine parameters of the power conversion process in the Power Extraction Structure (PETS) installed in the Two-beam Test Stand in CTF3.

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MOPRO017

Low Emittance Lattice Cell with Large Dynamic Aperture

sextupole, lattice, dynamic-aperture, storage-ring

99

A.V. Bogomyagkov, E.B. Levichev, P.A. Piminov
BINP SB RAS, Novosibirsk, Russia

Funding: The work is supported by the Ministry of Education and Science of the Russian Federation.
Compact low emittance lattice cell providing large dynamic aperture is essential for development of extremely low (pm range) emittance storage rings. As it is well known, a pair of identical sextupoles connected by a mi-nus-identity matrix transformer in ideal case of kick-like magnets provides infinite dynamic aperture. Though the finite sextupole length degrades the aperture, it is still large enough, and in this report we discuss development of the low emittance cell providing the I condition for both horizontal and vertical chromatic sextupoles.

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MOPRO025

Electron Beam Injection System for SuperKEKB Main Ring

injection, septum, betatron, synchrotron

122

T. Mori, N. Iida, M. Kikuchi, T. Mimashi, Y. Sakamoto, S. Takasaki, M. Tawada
KEK, Ibaraki, Japan

The SuperKEKB project is in progress toward the initial physics run in the year 2015. It assumes the nano-beam scheme, in which the emittance of the colliding beams is ε=4.6\mbox{nm}. The emittance of the injected beam is ε=1.46\mbox{nm}. To acheave such a low emittance, it is vitally important to preserve the emittance during the transport of the beam from the linac to the main ring. One of the most difficult sections is the injection system. It has been pointed out that the injected beam has possibility of leading to blowup in the ring, which is caused by a beam-beam interaction with the stored positron beam. To avoid the beam blowup, the synchrotron injection is adopted as a backup option. The orbit of the electron injection beam has been designed and the septum magnet prototype has been constructed. The optics study for electron injection and the current R&D status for the septum magnet will be reported in this paper.

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MOPRO029

Feed Forward Orbit Correction in the CLIC Ring to Main LINAC Transfer Lines

kicker, extraction, simulation, collimation

131

R. Apsimon, A. Latina, D. Schulte, J.A. Uythoven
CERN, Geneva, Switzerland

The emittance growth in the betatron collimation system of the 27 km long transfer lines between the CLIC damping rings and the main LINAC depends strongly on the transverse orbit jitter. The resulting stability requirements of the damping ring extraction elements seem extremely difficult to achieve. Position and angle feed forward systems in these long transfer lines bring the specified parameters of the extraction elements within reach. The designs of the optics and feed forward hardware are presented together with tracking simulations of the systems.

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MOPRO031

Abort Gap Cleaning for LHC Run 2

luminosity, operation, extraction, quadrupole

138

J.A. Uythoven, A. Boccardi, E. Bravin, B. Goddard, G.H. Hemelsoet, W. Höfle, D. Jacquet, V. Kain, S. Mazzoni, M. Meddahi, D. Valuch
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

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MOPRO036

Beam Life Time and Stability Studies for ELENA

electron, antiproton, simulation, vacuum

154

J. Resta-López, O. Karamyshev, D. Newton, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev, D. Newton, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Funding: Work supported by the EU under Grant Agreement 624854 and the STFC Cockcroft Institute Core Grant No. ST/G008248/1.
The Extremely Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which shall be constructed at CERN to decelerate antiprotons to energies as low as 100 keV. At such low energies it is very important to carefully take contributions from electron cooling and heating effects (e.g. on the residual gas) into account. Detailed investigations into the ion kinetics under consideration of effects from electron cooling and scattering on the residual gas have been carried out using the BETACOOL code. In this contribution a consistent explanation of the different physical effects acting on the beam in ELENA is given. Beam lifetime, equilibrium momentum spread and emittance are all estimated based on numerical simulations. Finally, optimum machine settings are presented as a result of optimization studies.

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MOPRO047

Low Emittance Storage Ring Design for CANDLE project

storage-ring, booster, lattice, dynamic-aperture

188

G.S. Zanyan, V. Sahakyan, A. Sargsyan, V.M. Tsakanov
CANDLE, Yerevan, Armenia

The most effective way to increase the brilliance of synchrotron light sources is the reduction of beam emittance. To improve the CANDLE synchrotron light source performance, a new low emittance facility has been designed with the account of the new developments in magnets fabrication technology of last decade. The lattices for the booster and storage rings are re-designed keeping the geometrical layout of the facilities. The new design provides the beam emittance in storage ring below 5nm with sufficient dynamic aperture. This report presents the main design considerations, the linear and non-linear beam dynamics aspects of the modified facility performance.

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MOPRO048

Update on Sirius, the New Brazilian Synchrotron Light Source

lattice, insertion, coupling, insertion-device

191

L. Liu, A.P.B. Lima, N. Milas, A.H.C. Mukai, X.R. Resende, A.R.D. Rodrigues, F. H. de Sá
LNLS, Campinas, Brazil

Sirius is a 3 GeV synchrotron light source that is being built by the Brazilian Synchrotron Light Laboratory (LNLS). The electron storage ring uses the multi-bend-achromat approach (5BA in this case) to achieve a very low beam emittance of 0.28 nm.rad. The 518 m circumference contains 20 straight sections of alternating 6 and 7 meters in length, to be used for insertion devices as well as injection and RF systems. The 5BA cell is modified to accommodate a thin high field dipole (for 1.4˚ deflection) in the center of the middle bend producing hard X-ray radiation (12 keV critical energy) with a modest contribution to the total energy loss. This high field dipole (2.0 T) will be made of permanent magnet material, whereas the low field (0.58 T) ones, responsible for the main beam deflection, will be electromagnetic. Many challenges are associated with this kind of lattice, including both in beam dynamics and in accelerator engineering, that require R&D on new techniques. In this paper we discuss the main issues and achievements for Sirius during the last year.

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MOPRO049

A Low Emittance Lattice Design for the Canadian Light Source

sextupole, quadrupole, lattice, dipole

194

L.O. Dallin, W.A. Wurtz
CLS, Saskatoon, Saskatchewan, Canada

The CLS presently has a 12 cell DBA lattice with a circumference of 170.88 m. By using conventional magnet designs an emittance of 18 nm-rad is achieved. Twelve 5 m straights are available for injection, an RF cavity and insertion devices. An emittance of 1 nm-rad (at 2.9 GeV) can be achieved replacing each DBAs with multi-bend achromats (MBAs) while preserving the 12-fold symmetry although with a reduction of the length of the straights. To achieve the strong focussing required for low emittance very strong field gradients are required in the dipoles as well as the quadrupole and sextupole magnets. Sufficient dynamic aperture for off-axis injection and Touschek lifetime may be possible.

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MOPRO053

Study of Upgrade Scenarios for the SOLEIL Storage Ring

lattice, optics, dipole, sextupole

203

R. Nagaoka, P. Brunelle, X.N. Gavaldà, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

Within the scope of a future major upgrade of the SOLEIL storage ring, presently having the energy of 2.75 GeV, the circumference of 354 m and the horizontal emittance of 3.7 nm.rad, towards a Diffraction Limited Storage Ring (DLSR), the present paper presents and discusses the outcomes of a series of studies launched to explore different possible scenarios for the magnet lattice arrangement, under the constraint of making the upgrade in the same existing machine tunnel. Two scenarios were presented earlier in this context, which both preserved all the existing free straight sections for insertions, though the bending magnet positions were not strictly conserved. The purpose of the extended studies is to explore, in particular, the range of horizontal emittance that can be reached by hypothetically removing some of the existing geometric constraints, such as suppressing or shortening partially the straight sections. The emittance range is equally studied by fulfilling rigorously all constraints. The dependence of the nonlinear properties of the magnet lattice on the linear optics is simultaneously investigated.

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MOPRO055

ESRF Upgrade Phase II Status

vacuum, lattice, storage-ring, sextupole

209

J.-L. Revol, P. Berkvens, J.C. Biasci, J-F. B. Bouteille, N. Carmignani, J. Chavanne, F. Ewald, L. Farvacque, L. Goirand, M. Hahn, L. Hardy, J. Jacob, J.M. Koch, G. Le Bec, S.M. Liuzzo, T. Marchial, D. Martin, B. Nash, T.P. Perron, E. Plouviez, P. Raimondi, K.B. Scheidt, V. Serrière, R. Versteegen
ESRF, Grenoble, France

The ESRF is close to the end of the first phase (2009-2015) of its Upgrade Programme and has defined the objectives for the ensuing second phase. It envisions a major upgrade of the source to best serve the new science opportunities. The ESRF Council endorsed the proposal to perform the technical design study of a new 7-bend achromat lattice. This configuration will allow the storage ring to operate with a decrease in horizontal emittance by a factor of about 30 and a consequent increase in brilliance and coherence of the photon beam. This paper reports on the status of the accelerator project, highlighting the progress in the technical design.

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MOPRO057

Undulator Photon Beams with Orbital Angular Momentum

undulator, photon, experiment, storage-ring

213

J. Bahrdt, K. Holldack, P. Kuske, R. Müller, M. Scheer, P.O. Schmid
HZB, Berlin, Germany

Photons carrying orbital angular momentum (OAM) are present in the off-axis radiation of higher harmonics of helical undulators. Usually, the purity and visibility of OAM photons is blurred by electron beam emittance. However, high brightness OAM beams are expected in ultimate storage rings and FELs, and they may trigger a new class of experiments utilizing the variability of the topological charge, a 3rd degree of freedom besides wavelength and polarization. We report on the first detection of OAM photons in helical undulator radiation in the 3rd generation storage ring BESSY II. Measurements and simulations are compared and the impact of emittance and energy spread is discussed.

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MOPRO064

An Ultra-low Emittance Model for the ANKA Synchrotron Radiation Source Including Non-linear Effects

sextupole, lattice, quadrupole, synchrotron

228

A.I. Papash, A.-S. Müller
KIT, Eggenstein-Leopoldshafen, Germany
E.B. Levichev, P.A. Piminov, S.V. Sinyatkin, K. Zolotarev
BINP SB RAS, Novosibirsk, Russia

An ultra-low emittance lattice based on the ANKA ring geometry is under investigation in framework of the feasibility studies for a compact low emittance synchrotron light source at the Karlsruhe Institute of Technology (Germany). An attempt to apply the concept of split bending magnets cells and to reduce the natural emittance of the bare ANKA DBA lattice from 90 nm×rad down to 2.5 nm×rad with not-vanishing dynamic aperture is described in this paper. The TME cell with split bends and a quadrupole lens in-between as well as a pair of non-interleaved sextupole lenses separated by “I ” unit transfer matrix of betatron oscillations allows to decrease the theoretical minimum emittance of ANKA ring down to approximately 6 nm×rad. Further reduction of the phase space volume requires to brake “I ” symmetry and add extra families of sextupoles, locate an additional high order field elements inside the quadrupoles, optimize the phase advance between sextupole families, shift the betatron tune point, enlarge the sextupole strength and other measures. Results of simulations are reported.

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MOPRO074

Super Bright Lattice for the Iranian Light Source Facility Storage Ring

lattice, dipole, storage-ring, radiation

255

H. Ghasem
IPM, Tehran, Iran
E. Ahmadi
ILSF, Tehran, Iran

To have a competitive leading position in the future and to obtain ultra low beam emittance, save energy and minimizing operation cost, we have designed lattice based on the 5 low field dipole magnets per cell for the storage ring of Iranian light Source Facility (ILSF). The designed lattice has the capability of both soft and hard x-ray radiation from central dipoles. In this paper, we give specifications of lattice linear and nonlinear optimization and review properties of the radiated x-ray.

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MOPRO075

Evolution of Elettra towards an Ultimate Light Source

dipole, lattice, quadrupole, photon

258

E. Karantzoulis
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Considerations of possible lattices aiming to transform Elettra into an Ultimate Light Source (ULS), the best solution found and some considerations regarding the accelerator components are presented and discussed

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MOPRO076

Elettra Status and Upgrades

operation, controls, coupling, dipole

261

E. Karantzoulis, A. Carniel, S. Krecic
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with the latest studies and upgrades.

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MOPRO077

Betatron Coupling Numerical Study at Elettra

coupling, betatron, quadrupole, lattice

264

S. Di Mitri, E. Karantzoulis
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

Elettra lacks skew quadrupoles and the coupling is controlled via the vertical orbit. Elettra has typical operational coupling of 1%, values as low as 0.3% were reached but however not easily established and reproducible. In order to control the coupling in a reproducible manner skew quadrupoles must be installed. Simulations of the betatron coupling and correction for the Elettra synchrotron light source were performed and are here presented. The numerical study is based on measured machine misalignments and carried out with the ELEGANT particle tracking code. The inclusion of families of skew quadrupoles in the existing lattice is investigated and shown to be conclusive for the coupling correction at the level of 0.1%.

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MOPRO078

The SPARC_LAB Thomson Source Commissioning

electron, laser, photon, linac

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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MOPRO079

Design of Ultra-low Emittance Ring with Multi-bend Lattice on a Torus-knot

lattice, quadrupole, sextupole, insertion

271

A. Miyamoto, S. Sasaki
HSRC, Higashi-Hiroshima, Japan

We proposed a torus knot type synchrotron radiation ring in that the beam orbit does not close in one turn but closes after multiple turns around the ring. Currently, we are designing a new ring based on the shape of a (11, 3) torus knot for our future plan ‘HiSOR-II.’ This ring is mid-low energy light source ring with a beam energy of 700 MeV. Recently some light source rings are achieving very low emittance that reaches a diffraction limited light by adopting a multi-bend scheme to the arc section of the ring. It is not difficult for low-mid energy VUV-SX light source ring because the electron beam less than 10 nmrad can provide the diffraction limited light in the energy less than 10eV. However the multi-bend lattice has many families of the magnets, therefore it is not easy to decide the parameters of the lattice. Especially, it is difficult for the torus knot type SR ring because there is a lot of geometric limitation around the cross points of orbits. We present the details of the designing procedure and the specifications of the ultra-low emittance light source ring having innovatively odd shape.

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MOPRO081

Resonance Frequency Feedback System for a Precise Magnet Alignment using Multi-vibrating Wires

feedback, resonance, quadrupole, alignment

277

K. Fukami, N. Azumi, T. Fujita, T. Honiden, H. Kimura, T. Nakanishi, Y. Okayasu, C. Zhang
JASRI/SPring-8, Hyogo-ken, Japan
K. Kajimoto, T. Watanabe
SES, Hyogo-pref., Japan
S. Matsui
RIKEN/SPring-8, Hyogo, Japan

An ultimate storage ring (USR) is being designed at synchrotron radiation facilities in the world. USR can generate theoretically minimum synchrotron radiation because emittance of the USR is less than diffraction limit of the radiation. The USR requires high alignment precision of micro-meter order. A vibrating wire method (VWM) has widely been used for such a high precision alignment. An error field of multi-pole magnet is estimated by detecting a vibration of a single wire excited with AC current. The wire position, where no vibration is excited, is defined as the magnetic center. The applied frequency is kept on a resonant frequency, which may drift due to temperature change etc. during the measurement. To trace the resonant frequency at all times, we developed a frequency feedback system. It is necessary to trace the resonance, even when the wire is set in the vicinity of the magnetic center where the magnetic field is nearly zero. Here we propose to install one or two additional wires parallel to the original wire. The additional wires off the center can detect the vibration frequency with enough S/N ratio. We discuss the effectiveness of it for quick and reliable alignment.

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MOPRO083

Design Study of High Brilliant Optics at the SPring-8 Storage Ring

photon, brilliance, optics, electron

283

Y. Shimosaki, T. Aoki, K. Fukami, K.K. Kaneki, K. Kobayashi, M. Masaki, C. Mitsuda, H. Ohkuma, M. Shoji, K. Soutome, S. Takano, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan

At the SPring-8 storage ring, design study of beam optics concentrating particularly on increasing brilliance, not flux density, is in progress besides continuous efforts of increasing both brilliance and flux density for the user optics. The natural emittances are theoretically reduced from 2.41 nmrad at 8 GeV to 2.27 nmrad (8 GeV), 1.78 nmrad (7 GeV) and 1.33 nmrad (6 GeV) by utilizing an emittance damping effect by the insertion devices. The designed optics has experimentally been examined at 6 GeV, and the electron beam parameters have been confirmed by measurements at the diagnostics beamlines.
* Y. Shimosaki et al., “New Optics with Emittance Reduction at the SPring-8 Storage Ring”, IPAC13, MOPEA027.

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MOPRO091

Fundamental Limits of Velocity Bunching of High-brightness Electron Beams

bunching, electron, cavity, gun

304

A. Opanasenko, V.V. Mytrochenko
NSC/KIPT, Kharkov, Ukraine
V.A. Goryashko, V. Zhaunerchyk
Uppsala University, Uppsala, Sweden
P.M. Salen
FYSIKUM, AlbaNova, Stockholm University, Stockholm, Sweden

The interest in superradiant THz sources based on the coherent transition, synchrotron or undulator radiation grows continuously and such sources require high-quality electron bunches with low emittance, high charge and sub-picosecond (sub-ps) duration. Since accelerator-based THz sources are usually driven by relatively low energy electron bunches of a few tens of MeV, space-charge makes bunch compression to sub-ps level very challenging. In the present work we investigate the feasibility of ballistic bunching down to sub-ps duration while preserving the transverse phase-space quality. We found that in order to compensate for the nonlinear dependency of the arrival time on the energy as well as bunch deformations induced by space-charge effects, one needs to apply a nonlinear energy chirp. This chirp permits to maximize the bunch compression and can be realized by exciting a cavity with higher harmonics of the fundamental frequency. Issues related to synchronizing the harmonics are discussed and the analytical analysis is complemented by simulations with PARMELA.

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MOPRO094

TPS Commissioning Exercise Performed on the TLS

injection, storage-ring, quadrupole, lattice

307

F.H. Tseng, H.-P. Chang, M.-S. Chiu, S.J. Huang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) commissioning exercise by using the high-level accelerator physics application programs (HL-APAP) has been performed on the operational 1.5 GeV Taiwan Light Source (TLS) storage ring. It includes steering the injection beam in the first turn to achieve multi-turns and stored beam with the help of the RESOLVE analysis. The orbit correction programs using different algorithms such as SVD, Householder transformation, and local bumps were applied to reduce the closed orbit distortion of the stored beam and to adjust the beam orbit to pass through those field centers of quadrupoles indicated by the corresponding BPMs. The golden orbit defined by the measured data of BPMs corresponding to each quadrupole field center was based on the Beam Based Alignment (BBA). After approach the stored beam orbit to the golden orbit, we save all the BPMs data as the target orbit for machine operation. The lattice calibration is then performed by the LOCO. The detail of the commissioning exercise is described in this report.

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MOPRO097

Status of the Turkish Synchrotron Radiation Source Machine Design

radiation, storage-ring, synchrotron, synchrotron-radiation

313

Z. Nergiz, H. Aksakal
Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey
A.A. Aksoy, C. Kaya
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
Ö.K. Öztürk
Dogus University, Istanbul, Turkey

Funding: Work is supported by Ministry of Development of Turkey with Grand No: DPT2006K-120470
Turkish synchrotron radiation source named TURKAY, is a part of the TAC (Turkish Accelerator Center) Project , is at conceptual design process. The radiation properties of a SR sources are strongly depends on the magnetic lattice of the storage ring. The storage ring is designed to obtain low emittance electron beam at 3 GeV energy. Optimization of the lattice properties, including the non-linear dynamics, is described in detail. Radiation properties are calculated by the example of some existing undulators from the other SR facilities.

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MOPRO098

Compact Electron Storage Ring Concepts for EUV and Soft X-ray Production

storage-ring, damping, wiggler, dipole

316

H.L. Owen, S.A. Geaney, M. Kenyon
UMAN, Manchester, United Kingdom
J.K. Jones, D.J. Scott
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Funded in part by the Science and Technology Facilities Council
We discuss the use of two novel techniques to deliver low emittance from a compact electron ring at energies around 1 GeV, suitable for EUV and soft X-ray synchrotron radiation production. The first method is the circulation of non-equilibrium electron bunches, which is made feasible using high repetition rate linacs and very fast bunch-by-bunch injection and extraction. The second method is to utilise a stacked storage ring in which two rings are coupled, and in which the strong damping wigglers in one ring depress the emittance in the other. We present example designs of each approach, noting that these methods may be used in combination with other emittance reduction techniques.

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MOPRO099

Long-term Stability of the Diamond Light Source Storage Ring

survey, storage-ring, alignment, insertion

319

M. Apollonio, K.A.R. Baker, R. Bartolini, W.J. Hoffman, J. Kay, V.C. Kempson, I.P.S. Martin
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

The Diamond Storage Ring (SR) has been in operation since January 2007. This paper summarises a number of measurements that have been made over that period to monitor the SR stability in height and position including general survey, Hydrostatic Levelling System (HLS), horizontal and vertical magnet corrector strengths as well as Radio Frequency (RF) measurements that have given an indication of changing circumference.

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MOPRO104

Low-Energy Intrabeam Scattering Measurements at the Spear3 Storage Ring

storage-ring, damping, radiation, lattice

334

K. Tian, W.J. Corbett, X. Huang, J.A. Safranek
SLAC, Menlo Park, California, USA

Intrabeam scattering (IBS) can cause emittance growth in diffraction limited light sources. At lower beam energy, the IBS effect is expected to be more pronounced. To study these effects we have developed a series of low energy lattices in SPEAR3 with beam energy ranging from 3GeV to 700MeV. The horizontal beam size and bunch length are measured as a function of beam energy and compared with theoretic calculations.

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MOPRO105

Study of Ultra-low Emittance Design for SPEAR3

dipole, sextupole, quadrupole, electron

337

M.-H. Wang, R.O. Hettel, X. Huang, T. Rabedeau, J.A. Safranek, K. Tian
SLAC, Menlo Park, California, USA

Funding: Work supported by the US Department of Energy under contract number: DE-AC02-76SF00515
Since its 2003 construction, the SPEAR3 synchrotron light source at SLAC has continuously improved its performance by raising beam current, top-off injection, small alpha and smaller emittance. This makes SPEAR3 one of the most productive light sources in the world. Now to further enhance the operation of SPEAR3, we are looking into the possibility of converting SPEAR3 to a multi-bend achromat storage ring within its site constraint.

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MOPRO107

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

gun, linac, 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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MOPME008

3d Full Electromagnetic Beam Dynamics Simulations of the Pitz Photoinjector

simulation, laser, cathode, gun

391

Y. Chen, E. Gjonaj, W.F.O. Müller, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: work supported by DESY, Hamburg and Zeuthen sites
The electromagnetic (EM) simulation software CST STUDIO SUITE® * has been applied to investigate the beam dynamics for the electron gun of the Photo Injector Test facility at DESY, Zeuthen site (PITZ). A series of 3D beam dynamics simulations are performed to study the bunch injection process at PITZ with the objective of clarifying the discrepancies between measurements and simulations. Multiple comparisons are presented for the transverse emittance and the total emitted charge between the measurement data and simulation results using CST STUDIO SUITE®and Astra **.
* Computer Simulation Technology AG, website: http://www.cst.com/
** K. Floettmann A Space Charge Tracking Algorithm, user manual (version 3), 2011

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MOPME032

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

rfq, simulation, linac, 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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MOPME037

The Development of Stochastic Processes in COSY Infinity

scattering, simulation, lattice, controls

457

J.D. Kunz
IIT, Chicago, Illinois, USA
M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
P. Snopok
Illinois Institute of Technology, Chicago, Illlinois, USA

Funding: Work supported by U.S. Department of Energy.
COSY Infinity is an arbitrary-order beam dynamics simulation code. It can determine high-order transfer maps of combinations of particle optical elements. New features are being developed for inclusion in COSY to follow the distribution of particles through matter. To study in detail the properties of muons passing through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map–Monte-Carlo approach in which transfer map methods describe the average behavior of the particles including energy loss, and Monte-Carlo methods are used to provide small corrections to the predictions of the transfer map accounting for the stochastic nature of scattering and straggling of particles. The advantage of the new approach is that the vast majority of the dynamics is represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed will aid the optimization of muon cooling channels. Progress on the development of the required algorithms is reported.

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MOPME038

Space Charge Simulation in COSY using The Fast Multipole Method

space-charge, multipole, simulation, collider

460

B.T. Loseth, M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
P. Snopok
Fermilab, Batavia, Illinois, USA
H. Zhang
JLab, Newport News, Virginia, USA

A method is implemented in COSY Infinity that allows the computation of space charge effects of arbitrary and large distributions of particles in an efficient and accurate way based on a variant of the Fast Multipole Method (FMM). It relies on an automatic multigrid-based decomposition of charges in near and far regions and the use of high-order differential algebra methods to obtain decompositions of far fields that lead to an error that scales with a high power of the order. Given an ensemble of N particles, the method allows the computation of the self-fields of all particles on each other with a computational expense that scales as O(N). Furthermore, the method allows the computation of all high-order multipoles of the space charge fields that are necessary for the computation of high-order transfer maps and all resulting aberrations. Space charge effects are crucial in modeling the latter stages of the six-dimensional (6D) cooling channel for the Muon Collider. Results of simulating the 6D cooling channel for the Muon Collider using the FMM method and other tools and improvements implemented for ionization cooling lattices are presented.

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MOPME048

CLIC Decelerator - Machine Protection

quadrupole, alignment, operation, collider

482

L.M. Hein, J. Esberg, M. Jonker
CERN, Geneva, Switzerland

The Compact Linear Collider CLIC is based on a four beam scheme, two colliding beams (main beams) and two drive beams, which are used to accelerate the main beams. The intended drive beam parameters exceed the "safe beam" threshold by a factor of 100. Hence, in case of a beam impact serious structural damages of the accelerator equipment are expected. In order to avoid structural damages caused by the drive beam detailed studies of its beam dynamics are on-going. In this paper the major characteristics of the drive-beam beam-dynamics and preliminary machine protection results are summarised.

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MOPME049

Design Considerations of the Final Turnaround Regions for the CLIC Drive Beam

lattice, extraction, kicker, dipole

485

R. Apsimon, J. Esberg, A. Latina, D. Schulte, J.A. Uythoven
CERN, Geneva, Switzerland

The optics design of the final turnaround regions for the CLIC drive beam is presented. This includes the extraction region, the turnaround loop and the phase feed forward chicane for correcting errors on the bunch phase. The design specifications of the kicker and septum magnets are provided. Tracking simulations and detailed studies of coherent and incoherent synchrotron radiation have been used to optimise the optics in the turnaround region in order to minimise transverse and longitudinal emittance growth.

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MOPME084

Proposal for a Soft X-ray Diffraction Limited Upgrade of the ALS

lattice, insertion, insertion-device, injection

567

C. Steier, A. Anders, D. Arbelaez, K.M. Baptiste, W. Barry, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, R.W. Falcone, J.-Y. Jung, S.D. Kevan, S. Kwiatkowski, T.H. Luo, A. Madur, H. Nishimura, J.R. Osborn, G.C. Pappas, L.R. Reginato, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, H. Tarawneh, W.L. Waldron, W. Wan
LBNL, Berkeley, California, USA

Funding: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Advanced Light Source (ALS) at Berkeley Lab has been updated many times and remains as one of the brightest sources for soft x-rays worldwide. However, recent developments in technology, accelerator physics and simulation techniques open the door to much larger future brightness improvements. Similar to proposals at several other 3rd generation sources, this could be achieved by reducing the horizontal emittance with a new ring based on a multi-bend achromat lattice, reusing the existing tunnel, as well as much of the infrastructure and beamlines. After studying candidate lattice designs, development efforts in the last year have concentrated on technology and physics challenges in four main areas: Injection, Vacuum Systems, Magnets and Insertion Devices, as well as main and harmonic RF systems.

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MOPRI007

Design and Simulation of a High Intensity Muon Beam Production for Neutrino Experiments.

target, proton, solenoid, factory

589

H. K. Sayed, H.G. Kirk, R.B. Palmer, D. Stratakis
BNL, Upton, Long Island, New York, USA
K.T. McDonald
PU, Princeton, New Jersey, USA
D.V. Neuffer
Fermilab, Batavia, Illinois, USA

The production process of pions which then decay into muons, yields a muon beam with large transverse and longitudinal emittances. Such beam requires phase space manipulation to reduce the total 6D emittance before it could go through any acceleration stage. The design of the muon beam manipulation is based on Neutrino Factory front end design. In this study we report on a multi objective - multivariable global optimization of the front end using parallel genetic algorithm. The parallel optimization algorithm and the optimization strategy will be discussed and the optimized results will be presented as well.

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MOPRI012

High Current Low Emittance Proton And Deuteron Beam Production at SMIS 37

plasma, ion, extraction, proton

604

I. Izotov, S. Golubev, S. Razin, V. Sidorov, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia
T. Kalvas, H. A. Koivisto, O.A. Tarvainen
JYFL, Jyväskylä, Finland

This work presents the latest results of high current proton and deuteron beam production at SMIS 37 facility at the Institute of Applied Physics (IAP RAS). This facility creates and heats up the plasma by 37.5 GHz gyrotron radiation with power up to 100 kW in a simple mirror trap meeting the ECR condition. High microwave power and frequency allow sustaining plasma of significantly higher density (Ne up to 2·10¹³ cm^-3) in comparison to conventional ECRISes or other microwave ion sources. The low ion temperature, on the order of a few eV, is beneficial to produce ion beams with low emittance. Latest experiments at SMIS 37 were performed using a single-aperture two-electrode extraction system. Various diameters of plasma electrode apertures i.e. 5 mm, 7 mm, 10 mm, were tested yielding proton and deuteron beams with currents up to 500 mA with RMS emittance lower than 0.2 π·mm·mrad at extraction voltages up to 45 kV. The maximum beam current density was measured to be 800 mA/cm². A possibility of further improvement through the development of an advanced extraction system is discussed.

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MOPRI017

Status of AREAL RF Photogun Test Facility

gun, electron, laser, operation

620

B. Grigoryan, G.A. Amatuni, V.S. Avagyan, H. Avdishyan, H. Davtyan, A.A. Gevorgyan, L.H. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, A. Lorsabyan, M. Manukyan, I.N. Margaryan, N. Martirosyan, T.H. Mkrtchyan, S. Naghdalyan, V.H. Petrosyan, H. Poladyan, V. Sahakyan, A. Sargsyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, V. V. Vardanyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
T.K. Sargsyan
LT-PYRKAL cjsc, Yerevan, Armenia

Advanced Research Electron Accelerator Laboratory (AREAL) is a 20 MeV laser driven RF linear accelerator which is being constructed in the CANDLE institute. The construction of phase-1 is finished and at present the machine commissioning is in progress. In phase-1 a photocathode RF gun provides a 5 MeV small emittance electron beam with the 100 pC bunch charge and variable electron bunch length from 0.5 to 8 ps. Two main operation modes are foreseen for this phase – single and multibunch regimes to satisfy experimental demands. We report the status of linac, first experience and nearest machine run schedule. The brief review of the facility, main parameters, performance and first results are presented.

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MOPRI018

Influence of Growth Method on K3Sb Photocathode Structure and Performance

cathode, synchrotron, experiment, scattering

624

S.G. Schubert, T. Kamps, M. Schmeißer
HZB, Berlin, Germany
K. Attenkofer, J. Smedley
BNL, Upton, Long Island, New York, USA
E.M. Muller
SBU, Stony Brook, New York, USA
H.A. Padmore, J.J. Wong
LBNL, Berkeley, California, USA
M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
J. Xie
ANL, Argonne, Illinois, USA

Funding: Supported by Director, OoS., OBES of US DOE, Contract DE-AC02-05CH11231, DE-AC02-98CH10886, KC0407-ALSJNTI0013, DE-SC0005713, germ. BMBF, Land Berlin, Helmholtz Assoc.. Use of CHESS by NSF, DMR-0936384.
Future high brightness photoelectron sources delivering >100 mA average current call for a new generation of photocathodes. Materials which qualify for this purpose should exhibit low intrinsic emittance, long lifetime and high quantum efficiency at photon energies in the visible range of the spectrum to relax drive laser requirements. A combination of material science techniques are used to determine the influence of the growth parameters on structure and performance of photocathode materials . In-situ XRR, XRD and GiSAXS measurements were performed at the synchrotron radiation sources, NSLS and CHESS. The growth of K3Sb, a precursor material of one of the prime candidates CsK2Sb, was studied intensively to optimize this intermediate growth step in terms of quantum efficiency and roughness. Three methods, a “layer by layer” type and a “super-lattice type” were examined. K3Sb exists in two crystallographic phases, namely cubic and hexagonal. The cubic phase exhibits a higher quantum efficiency at 532 nm than the hexagonal phase and transforms more easily into CsK2Sb, tuning this phase is believed to be one of the key parameters in the CsK2Sb growth.

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MOPRI023

Simulation of the ELBE SRF Gun II

gun, simulation, SRF, laser

636

P.N. Lu, A. Arnold, U. Lehnert, P. Murcek, J. Teichert, H. Vennekate, R. Xiang
HZDR, Dresden, Germany

Funding: EuCARD, contract number 227579 German Federal Ministry of Education and Research grant 05 ES4BR1/8 LA³NET, Grant Agreement Number GA-ITN-2011-289191
By combining the code of ASTRA and elegant in a user-friendly interface, a simulation tool is developed for the ELBE SRF Gun II. The photoelectric emission and first acceleration to several MeV in the gun cavity are simulated by ASTRA with a 1D Model, where the space charge effect is considered. The dependence of the beam quality on key parameters is studied, and a compromised optimization for a 77 pC beam is used for further elegant simulation of the beam transport through a dogleg and ELBE Linacs. Proper settings of the magnets and RF phases are the main targets of improving the beam quality. Up to now the best simulation result is an electron bunch with the energy of 47 MeV, energy spread of 66 keV, bunch length of 0.35 ps and transverse emittance of 1.9 μm and 2.7 μm in the two perpendicular directions.

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MOPRI032

A STUDY ON ROBUSTNESS OF NEA-GAAS PHOTOCATHODE*

cathode, electron, vacuum, experiment

664

K. Uchida, R. Kaku, M. Kuriki, K. Miyoshi, Y. Seimiya, N. Yamamoto
HU/AdSM, Higashi-Hiroshima, Japan
H. Iijima
Tokyo University of Science, Tokyo, Japan

Electron source is one of the most important component in the advanced linac. There is a strong demand on the high performance cathode, such as small emittance, high brightness, and short pulse generation. NEA-GaAs photo-cathode is a unique technology which is capable for generating highly polarized and extremely low emittance beam. Quantum efficiency (QE) of the cathode is high in near IR region, so it is favor to generate a high current density beam. These advantages are originated to the Negative Electron Affinity (NEA) surface, but it is fragile so the operational lifetime is limited. A study on a robust NEA surface cathode is reported. According to the hetero-junction model, Cs-Te thin film deposited on GaAs forms a robust NEA surface. We performed the Cs-Te evaporation experiment on a clean GaAs cathode and measured QE spectra. We found that some sample showed a high quantum efficiency up to 900nm wavelength which strongly suggested a NEA surface formation.

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MOPRI033

Quasi-traveling Wave Side Couple RF Gun Commissioning for SuperKEKB

gun, cavity, cathode, coupling

667

T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou
KEK, Ibaraki, Japan

We are developing a new RF gun for SuperKEKB. High-charge low-emittance electron and positron beams are required for SuperKEKB. We will generate 7.0 GeV electron beam at 5 nC 20 mm-mrad by J-linac. In this linac, a photo cathode S-band RF gun will be used as the electron beam source. For this reason, we are developing an advanced RF gun. New RF gun which has two side coupled standing wave field is developed. We call it quasi traveling wave side couple RF gun. This gun has a strong focusing field at the cathode and the acceleration field distribution also has a focusing effect. Beam commissioning has been started with the new RF gun. I will report the result of beam commissioning.

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MOPRI035

Development of the Photocathode LiTi2O4 and Evaluations of the Initial Emittance

cathode, laser, electron, cavity

673

R. Inagaki, M. Hosaka, Y. Takashima, N. Yamamoto
Nagoya University, Nagoya, Japan
T. Hitosugi, S. Shiraki
Tohoku Uneversity, WPI-AIMR, Sendai, Japan
E. Kako, Y. Kobayashi, S. Yamaguchi
KEK, Ibaraki, Japan
M. Katoh, T. Konomi, T. Tokushi
UVSOR, Okazaki, Japan
Y. Okano
IMS, Okazaki, Japan

In UVSOR, the X-ray free electron laser (XFEL) based on linear accelerator with high pulse repetition about 1MHz has been designed as a candidate for the next radiation sources. We thought a combination of superconducting RF cavity and photocathode is an optimal electron gun for the new accelerator. For this electron gun, we propose a back-illuminated multi-alkali* photocathode with transparent superconductor LiTi2O4**. The reason for using LiTi2O4 is to reflect RF by using feature of penetration depth of superconductor, which is defined from London equation. This feature protects optical components from RF damage. However, LiTi2O4 is a new material and properties are not clear. We have measured the basic properties of this photocathode, such as magnetic susceptibility measurement and photoelectron spectrometry, etc. In this conference, we will explain the detail of the concept and advantage of this cathode, and show the result measured about the basic properties of this photocathode focusing on the initial emittance measurement.
* A. V. Lyashenko et al. JINST 4 P07005 (2009)
** Kumatani et al. APL 101 (2012) 123103″

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MOPRI040

Design and Analysis of an Electron Beam in an Electron Gun for X-Ray Radiotherapy

electron, gun, cathode, simulation

688

J.C. Lee, J.-S. Chai, M. Ghergherehchi, H.S. Kim, Y.S. Lee, S. Shin, Y.H. Yeon
SKKU, Suwon, Republic of Korea
B.N. Lee
KAERI, Dae-jeon, Republic of Korea

Funding: This work was supported by (IT R&D program of MSIP/KEIT [10043897] and MOTIE [13-DU-EE-12]) in KOREA.
Electron linear accelerators are used as x-ray generators for diagnosing the human body. In this paper conceptual design of electron beam for compact electron gun was calculated by using EGN2w and CST-Particle Studio codes. The structure of the electron gun was used for Pierce and diode type and the specification of electron beam was selected as 500 cGy/min. Specifications of designed electron gun were focused on current, beam size and normalized emittance. Optimized beam current, diameter and normalized emittance are 226.88 mA, 0.689 mm (Full width) and 1.03π mm• mrad, respectively by using two simulation codes. Accuracy of simulation was verified by comparison of emitted beam current which has error of 0.74%.
* Subhash C. Sharma et al., Journal of applied clinical medical physics, 8, 3 (2007) 119-125.
* Yuichiro Kamino et al., Med. Phys. 34 (2007) 1797-1808.

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MOPRI043

Study of a C-band Standing-wave Gun for the SwissFEL Injector

gun, cathode, solenoid, coupling

698

M. Schaer, S. Bettoni, A. Citterio, P. Craievich, M. Negrazus, L. Stingelin, R. Zennaro
PSI, Villigen PSI, Switzerland

The baseline design of the SwissFEL injector foresees the "PSI Gun 1", a 2.6-cell RF photo-cathode gun operating at S-band frequency, as the electron source. In this paper a new design is presented where a 5.6-cell C-band gun could replace the PSI Gun 1 with no impact on the rest of the injector setup. A conservative maximum gradient of 135 MV/m at the cathode is assumed which drives the electron beam faster into the relativistic regime and therefore allows to tolerate larger charge densities. The presented solution also foresees a coaxial RF coupling from the cathode side in order to place the gun solenoid as near to the photo-cathode as possible, improving the emittance compensation. Astra simulations showed that the transverse beam brightness can be doubled before the first bunch compressor preserving the low transverse emittance value as compared to the current design for the S-band injector configuration of SwissFEL.

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MOPRI044

Feasibility Study of an Ultrafast Electron Diffraction System in NSRRC

electron, gun, injection, cathode

701

P. Wang, K.C. Leou
NTHU, Hsinchu, Taiwan
N.Y. Huang, W.K. Lau, A.P. Lee
NSRRC, Hsinchu, Taiwan

It has been suggested that the MeV beam generated from a laser-driven photo-cathode rf gun can be used for ultrafast electron diffraction (UED)*. The feasibility of operating the NSRRC photo-cathode rf gun system for ultrashort bunch generation is being investigated. The results of space-charge tracking calculations show that a low emittance, few hundred femtoseconds MeV beam with reasonable bunch charge can be generated for single shot UED experiments. In this report, a preliminary design of this UED system will be discussed.
* X.J. Wang et al., in Proceedings of PAC'03, p.420.

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MOPRI045

Beam Diagnostics E-GUN Test Stand at TARLA

gun, electron, radiation, cathode

704

Ç. Kaya, A.A. Aksoy, A. Aydin, V. Karakilic, Ö. Karslı, E. Kazancı, B. Koc, S. Kuday, E.Ç. Polat, I. Sara, M. Yildiz
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
S. Özkorucuklu
Istanbul University, Istanbul, Turkey

Funding: Work supported by Turkish State Planning Organization (Grant No: DPT2006K-120470)
Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) facility, which is essentially proposed to generate oscillator mode FEL in 3-250 microns wavelengths range, will consist of totally normal conducting injector system with 250 keV beam energy, two superconducting RF accelerating modules in order to accelerate the beam 15-40 MeV. Continuous wave (CW) electron beam will provided by TARLA thermionic electron gun (E-GUN). Various aspects of the Thermionic EGUN test stand to deliver the necessary electron beam in terms of bunch charge, current, energy, emittance and profile for the beam diagnostic will be discussed. Primarily measurements results of electron beam energy loss and transverse orbit will be shown as well as beam image and shape measurements.
On behalf of TARLA Collaboration

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MOPRI049

An Ultracold Electron Facility in Manchester

electron, laser, space-charge, extraction

714

Ö. Mete, R. Appleby, W. Bertsche, M.A. Harvey, G.X. Xia
UMAN, Manchester, United Kingdom
S. Chattopadhyay
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A.J. Murray
The University of Manchester, The Photon Science Institute, Manchester, United Kingdom

An ultra-cold atom based electron source (UCAE) facility has been built in the Photon Science Institute (PSI), University of Manchester. In this paper, the key components and working principles of this source are introduced. Pre-commissioning status of this facility and the preliminary simulations results are presented.

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MOPRI050

Preliminary Study for an RF Photocathode based Electron Injector for AWAKE Project

laser, electron, focusing, plasma

717

Ö. Mete, G.X. Xia
UMAN, Manchester, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Chattopadhyay
Cockcroft Institute, Warrington, Cheshire, United Kingdom

AWAKE project, a proton driven plasma wakefield acceleration (PDPWA) experiment is approved by CERN. The PDPWA scheme consists of a seeding laser, a drive beam to establish the accelerating wakefields within the plasma cell; and a witness beam to be accelerated. The drive beam protons will be provided by the CERN's SPS. The plasma ionisation will be performed by a seeding laser and the drive beam protons to produce the accelerating wakefields. After establishing the wakefields, witness beam, namely, electron beam from a dedicated source should be injected into the plasma cell. The primary goal of this experiment is to demonstrate acceleration of a 5-15 MeV single bunch electron beam up to 1 GeV in a 10 m of plasma. This paper explores the possibility of an RF photocathode as the electron source for this PDPWA scheme based on the existing PHIN photoinjector at CERN. The modifications to the existing design, preliminary beam dynamics simulations in order to provide the required electron beam are presented in this paper.

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MOPRI053

High Repetition Rate Ultrafast Electron Diffraction at LBNL

electron, gun, experiment, laser

724

D. Filippetto, M. Mellado Munoz, H.J. Qian, F. Sannibale, W. Wan, R.P. Wells, M.S. Zolotorev
LBNL, Berkeley, California, USA

Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231"
Here we propose to use the APEX photo-gun as novel source for time-resolved electron diffraction studies. The electron source has been designed, built and successfully tested at LBNL. It combines a high accelerating field needed for bright beams, MeV electron energy essential for time resolution in gas-phase experiments and studies of bulk processes, together with continuous (CW) operations. Ultra-short electron pulses can be delivered with a maximum repetition rate of 186 MHz, enabling new science to be studied. We report the design of a dedicated electron diffraction beamline that fits in the space constraints of the APEX tunnel. Simulations of beam properties have been carried out with a genetic optimizer, showing 100 fs time resolution. Beam jitters in energy, time and position are currently being characterized, and a mitigation strategy via fast feedback loops is discussed.

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MOPRI055

APEX Present Experimental Results

cathode, gun, electron, laser

730

D. Filippetto, C.W. Cork, S. De Santis, L.R. Doolittle, G. Huang, R. Huang, W.E. Norum, C. F. Papadopoulos, G.J. Portmann, H.J. Qian, F. Sannibale, J.W. Staples, R.P. Wells
LBNL, Berkeley, California, USA
J. Yang
TUB, Beijing, 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 APEX electron source at LBNL combines high-repetition-rate and high beam brightness typical of photo-guns, delivering low emittance electron pulses at MHz frequency. Proving the high beam quality of the beam is an essential step for the success of the experiment. It would enable high repetition rate operations for brightness-hungry applications such as X-Ray FELs, and MHz ultrafast electron diffraction. A full 6D characterization of the beam phase space at the gun beam energy (750 keV) is foreseen in the first phase of the project. Diagnostics for low and high current measurements have been installed and tested, measuring the performances of different cathode materials in a RF environment with mA average current. A double-slit system allows the characterization of beam emittance at high charge and full current (mA). An rf deflecting cavity and a high precision spectrometer allow the characterization of the longitudinal phase space. Here we present the latest results at low and high repetition rate, discussing the tools and techniques used.

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MOPRI058

Metal Plasmonic Nanostructures Functionalized by Atomic Layer Deposition of MgO for Photocathode Applications

electron, cathode, vacuum, resonance

739

S.V. Baryshev, S.P. Antipov, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
M.R. Savina, A.V. Zinovev
ANL, Argonne, Illinois, USA
E. Thimsen
University of Minnesota, Minneapolis, USA

Funding: Euclid TechLabs LLC acknowledges support from the DOE SBIR program, grant No. DE-SC0009572.
To create high current, long lasting electron sources capable of providing sub-ps bunches, new photocathode concepts are sought. Most recently, plasmonic nanostructured metal surfaces or flat metal surfaces activated by an ultrathin MgO are under great attention. We report on a photocathode design combining these two approaches. It consists of plasmonic Ag nanoparticles (NPs) functionalized by 3 MgO monolayers (MLs). Ag NPs were synthesized by an aerosol method and MgO was grown by atomic layer deposition (ALD). The NPs geometry was tuned to obtain broadband >50% absorption in the entire blue range as evidenced by UV-vis. spectroscopy. The WF of 3 MgO MLs/Ag NPs multilayer was reduced by 1 eV compared to bare NPs, from 5 to 4 eV, as evidenced by UPS and Kelvin probe. Reduction by 1 eV is maximal for this pair of materials, and agrees well with experimental and theoretical findings. While the effect on WF is indeed significant, a special handling protocol for Ag before depositing MgO is a must. It would preserve a clean Ag surface with a WF of nearly 4 eV to achieve 3 eV upon ALD of MgO. This and other issues are under study to promote photocathode applications.

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MOPRI084

Beam Dynamic into the Transfer RIB Lines to the DESIR Facility at GANIL-SPIRAL2

quadrupole, ion, diagnostics, vacuum

806

L. Perrot, H. Cherif
IPN, Orsay, France

Funding: French ANR, Investissements d'Avenir, EQUIPEX Contract number ANR-11-EQPX-0012
The new ISOL facility SPIRAL2 is currently being built at GANIL, Caen France. SPIRAL2 will produce a large number of new radioactive ion beams (RIB) at high intensities. The DESIR facility will receive beams from the upgraded SPIRAL1 facility of GANIL (stable beam and target fragmentation), from the S3 Low Energy Branch (fusion-evaporation and deep-inelastic reactions) and from the SPIRAL2 production cave (n-induced fission of 238U, nucleon transfer and fusion-evaporation reactions). In order to deliver the RIB to the experimental set-ups installed in the DESIR hall, 110 meters of beam line have to be designed, originating from 3 different facilities. This paper will focus on the studies which have been done on these transfer lines: beam optics and errors calculations, quadrupoles, diagnostics and mechanical designs.

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MOPRI086

Status of the PXIE Low Energy Beam Transport Line

solenoid, ion, ion-source, rfq

812

L.R. Prost, R. Andrews, A.Z. Chen, B.M. Hanna, V.E. Scarpine, A.V. Shemyakin, J. Steimel
Fermilab, Batavia, Illinois, USA
R.T.P. D'Arcy
UCL, London, United Kingdom

Funding: Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
A CW-compatible, pulsed H⁻ superconducting RF linac (a.k.a. PIP-II) is envisaged as a possible path for upgrading Fermilab’s injection complex [1]. To validate the concept of the front-end of such machine, a test accelerator (a.k.a. PXIE) [2] is under construction. The warm part of this accelerator comprises a 10 mA DC, 30 keV H⁻ ion source, a 2m-long LEBT, a 2.1 MeV CW RFQ, and a MEBT that feeds the first cryomodule. In addition to operating in the nominal CW mode, the LEBT should be able to produce a pulsed beam for both PXIE commissioning and modelling of the front-end nominal operation in the pulsed mode. Concurrently, it needs to provide effective means of inhibiting beam as part of the overall machine protection system. A peculiar feature of the present LEBT design is the capability of using the ~1m-long section immediately preceding the RFQ in two regimes of beam transport dynamics: neutralized and space charge dominated. This paper introduces the PXIE LEBT, reports on the status of the ion source and LEBT installation, and presents the first beam measurements.

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MOPRI094

Proposal for a Slow Extraction System for a Biomedical Research Facility at CERN based on LEIR

extraction, resonance, sextupole, quadrupole

833

A. Garonna, D. Abler, C. Carli
CERN, Geneva, Switzerland

Funding: This work was partly funded by the Marie Curie Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract number PITN-GA-2008-215840-PARTNER.
A proposal has been made to accelerate ion beams ranging from hydrogen to neon with magnetic rigidities up to 6.7 Tm for biomedical experiments at CERN using the Low Energy Ion Ring (LEIR), in parallel to its continued operation for LHC and for SPS fixed target physics experiments. The feasibility of a new slow extraction system for LEIR based on the third integer resonance was studied with two possible resonance driving mechanisms: quadrupole-driven extraction and RF-knockout extraction. The extraction of fully stripped carbon ions (20-440 MeV/u kinetic energies) has been studied in detail. The requirement to keep the present performance of the machine for physics experiments imposes tight space constraints for the upgrade. The extraction scheme and the hardware requirements are described in this paper.

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MOPRI102

Upgrades of the CERN PS Booster Ejection Lines

optics, injection, quadrupole, dipole

858

W. Bartmann, J.L. Abelleira, K. Hanke, M. Kowalska
CERN, Geneva, Switzerland

The PS Booster extraction energy will be augmented from 1.4 to 2 GeV to reduce intensity limits due to space charge at the PS proton injection. For this upgrade the transfer line between PS Booster and PS will be modified for 2 GeV operation and pulse to pulse optics modulation for different beam types. Also the PS Booster measurement line will also be upgraded to 2 GeV and shall provide improved optics solutions for emittance measurements while reducing the loss levels recorded during operation. This paper describes the foreseen optics solutions for both transfer lines.

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TUXA01

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

injection, linac, dipole, 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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TUOAA03

Extra Low ENergy Antiproton ring ELENA: From the Conception to the Implementation Phase

experiment, antiproton, electron, extraction

910

C. Carli, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, T. Eriksson, S. Maury, S. Pasinelli, G. Tranquille
CERN, Geneva, Switzerland
W. Oelert
Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany

The Extra Low Energy Antiproton ring (ELENA) is a CERN project aiming at constructing a small 30 m circumference synchrotron to further decelerate antiprotons from the Antiproton Decelerator AD from 5.3 MeV to 100 keV. Controlled deceleration in a synchrotron equipped with an electron cooler to reduce emittances in all three planes will allow the existing AD experiments to increase substantially their antiproton capture efficiencies and render new experiments possible. The ELENA design is now well advanced and the project is moving to the implementation phase. Component design and construction are taking place at present for installation foreseen during the second half of 2015 and beginning of 2016 followed by ring commissioning until the end of 2016. New electrostatic transfer lines to the experiments will be installed and commissioned during the first half of 2017 followed by the first physics operation with ELENA. Basic limitations like Intra Beam Scattering limiting the emittances obtained under electron cooling and direct space charge effects will be reviewed and the status of the project will be reported.

Slides TUOAA03 [4.963 MB]

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TUYA01

First Experience with Electron Lenses for Beam-beam Compensation in RHIC

electron, solenoid, hadron, proton

913

W. Fischer, Z. Altinbas, D. Bruno, M.R. Costanzo, X. Gu, J. Hock, A.K. Jain, Y. Luo, C. Mi, R.J. Michnoff, T.A. Miller, A.I. Pikin, T. Samms, Y. Tan, R. Than, P. Thieberger, S.M. White
BNL, Upton, Long Island, New York, USA

Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The head-on beam-beam interaction is the dominant luminosity limiting effect in polarized proton operation in RHIC. To mitigate this effect two electron lenses were installed in the two RHIC rings. We summarize the hardware and electron beam commissioning results to date, and report on the first experience with the electron-hadron beam interaction. In 2014 RHIC is operating with gold beams only. In this case the luminosity is not limited by head-on beam-beam interactions and compensation is not necessary. The goals of this year’s commissioning efforts are a test of all instrumentation; the demonstration of electron and gold beam overlap; the demonstration of electron beam parameters that are sufficiently stable to have no negative impact on the gold beam lifetime; and the measurement of the tune footprint compression from the beam overlap. With these demonstrations, and a lattice with a phase advance that has a multiple of 180 degrees between the beam-beam interaction and electron lens locations, head-on beam-beam compensation can be commissioned in the following year with proton beams.

Slides TUYA01 [11.776 MB]

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TUOAB03

Nonlinear Optics for Suppression of Halo Formation in Space Charge Dominated Beams

focusing, quadrupole, space-charge, simulation

953

Y.K. Batygin, A. Scheinker
LANL, Los Alamos, New Mexico, USA
C. Li
IMP, Lanzhou, People's Republic of China

Traditional accelerator designs utilize linear focusing elements (quadrupoles, solenoids) to provide stable particle motion. High – intensity rms - matched non - uniform beams are intrinsically mismatched with linear focusing structure. It results in space charge induced beam emittance growth and halo formation, which can be suppressed in a quadrupole channel with higher-order multipole field components. In this paper, overview of FODO quadrupole channels with arbitrary multipoles is given. Effective averaged potential is presented for the structure with periodic combination of multipole lenses and quadrupoles. Density of matched beam avoiding emittance growth and halo formation is derived. Performed analysis allows matching of realistic beam with the internal structure of the focusing field. Beam dynamics studies with suppressed halo are presented and discussed.

Slides TUOAB03 [3.404 MB]

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TUPRO006

Strong-strong Beam-beam Simulation for the LHC Upgrade

simulation, cavity, resonance, luminosity

1006

J. Qiang, S. Paret
LBNL, Berkeley, California, USA
G. Arduini, T. Pieloni
CERN, Geneva, Switzerland
J. Barranco García
EPFL, Lausanne, Switzerland

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 using computing resources at the NERSC.
The LHC upgrade will significantly improve the performance of the current LHC operation with higher collision energy and luminosity. In the paper, we report on the progress in the strong-strong beam-beam simulation of the HL-LHC upgrade with crab cavity compensation. We will present the study of the effects of accelerator tune working points, dipole noise, and crab cavity noise on colliding beam emittance growth.

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TUPRO010

Origins of Transverse Emittance Blow-up during the LHC Energy Ramp

luminosity, injection, simulation, brightness

1021

M. Kuhn, G. Arduini, V. Kain, A. Langner, Y. Papaphilippou, M. Schaumann, R. Tomás
CERN, Geneva, Switzerland

During LHC Run 1 about 30 % of the potential peak performance was lost due to transverse emittance blow-up through the LHC cycle. Measurements indicated that the majority of the blow-up occurred during the energy ramp. Until the end of LHC Run 1 this emittance blow-up could not be eliminated. In this paper the measurements and observations of emittance growth through the ramp are summarized. Simulation results for growth due to Intra Beam Scattering will be shown and compared to measurements. A summary of investigations of other possible sources will be given and backed up with simulations where possible. Requirements for commissioning the LHC with beam in 2015 after Long Shutdown 1 to understand and control emittance blow-up will be listed.

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TUPRO023

Beam-beam Effects in Different Luminosity Levelling Scenarios for the LHC

luminosity, dynamic-aperture, experiment, beam-beam-effects

1061

X. Buffat, D. Banfi, G.R. Coombs
EPFL, Lausanne, Switzerland
W. Herr, T. Pieloni
CERN, Geneva, Switzerland

Adjusting luminosity and optimizing the luminous region in each interaction point of the LHC according to the experiments needs has become a requirement to maximize the efficiency of the different detectors. Several techniques are envisaged, most importantly by varying β* or a transverse offset at the interaction point. Coherent and incoherent stability in the presence of beam-beam effects will be discussed in realistic luminosity levelling scenarios for the LHC.

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TUPRO026

Possible Beam-beam and Levelling Scenarios for HL-LHC

luminosity, simulation, collider, hadron

1071

M.P. Crouch, R. Appleby
UMAN, Manchester, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
T. Pieloni
CERN, Geneva, Switzerland

Funding: Research supported by EU FP7 HiLumi LHC - Grant Agreement 284404
The upgrade of the LHC from the current set-up to high luminosity performances will provide new challenges from the point of view of beam-beam as well as other collective effects and luminosity levelling. We present the current possibilities for doing luminosity levelling for HL-LHC. We explore the merits and drawbacks of each option and briefly discuss the operational implications. The simplest option being levelling with an offset between the two beams. In particular, we look at the possibility of using flat beams in the IPs for all the available options and investigate their benefits and drawbacks, using the code COMBI. Flat beams would allow an additional degree of freedom, with the levelling only required in one of the planes at any given IP. To this end, various scenarios are looked at, both with and without crab cavities.

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TUPRO034

Beam-beam Interaction in the Asymmetric Energy Gold-gold Collision in RHIC

simulation, ion, experiment, collider

1093

Y. Luo, M. Blaskiewicz, M.R. Costanzo, W. Fischer, X. Gu, V.H. Ranjbar, S.M. White
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 this article, we study the beam-beam interaction in the possible future gold-gold collision with different particle energies in the Relativistic Heavy Ion Collider (RHIC). With different particle energies, the center-of-mass of collision is moving in the longitudinal direction during collision. Since the RF harmonic numbers are different for the two RHIC rings, bunches collide in 110 turns followed by 10 turns without collision. In this study, the stability of particles and the beam emittance growth are calculated through numeric simulations based on a 6-D weak-strong beam-beam interaction model.

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TUPRO035

Vertical Emittance at the Quantum Limit

quadrupole, storage-ring, sextupole, coupling

1096

R.T. Dowd, Y.E. Tan
SLSA, Clayton, Australia
K.P. Wootton
The University of Melbourne, Melbourne, Victoria, Australia

Further reduction of betatron coupling and vertical dispersion in the storage ring of the Australian Synchrotron Light Source has resulted in the achievement of a beam vertical emittance that is now dominated by the intrinsic quantum effects. This paper will detail the key elements in achieving a vertical emittance at the quantum limit and results achieved.

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TUPRO036

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

linac, 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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TUPRO037

Suppression Techniques of CSR Induced Emittance Growth in ERL Arcs

electron, simulation, synchrotron, betatron

1102

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

The Energy Recovery Linac (ERL) conception is a promising way of creating diffraction limited synchrotron light source. The high ERL beam quality (low emittance, short bunch and low energy spread) gives an opportunity to generate high brightness photon beams. One of the main requirements for the optic in such machines is the suppression of emittance growth. An important reason for beam degradation is the impact of Coherent Synchrotron Radiation (CSR) in bending magnets. CSR induced emittance dilution and methods of preservation both with and without compression are discussed in this article.

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TUPRO038

Beam Positioning Concept and Tolerance Considerations for BERLinPro

laser, linac, 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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TUPRO044

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

radiation, electron, linac, 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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TUPRO046

Beamlines with Two Deflecting Cavities for Transverse-to-Longitudinal Phase Space Exchange

quadrupole, cavity, beam-transport, controls

1129

V. Balandin, W. Decking, N. Golubeva
DESY, Hamburg, Germany

Optical systems for transverse-to-longitudinal emittance exchange involving single dipole-mode cavity were in great details studied during the last decade theoretically and experimentally. In this paper we discuss the question, if there are any advantages in usage of beamlines utilizing two deflecting cavities instead of one. The general analysis is presented and specific beamline designs are given as examples.

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TUPRO048

Dynamics of Twiss Parameters from the Geometrical Viewpoint

framework, betatron, survey

1135

V. Balandin, N. Golubeva
DESY, Hamburg, Germany

We show that with an appropriate parametrization the linear transport of the Twiss parameters can be viewed as a bilinear (or Moebius) map of the upper complex half-plane (which is the hyperbolic plane) into itself. Using then elementary techniques of hyperbolic geometry we classify transformations of the Twiss parameters into elliptic, hyperbolic and parabolic types and, for each type, present its typical phase space portraits.

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TUPRO051

Emittance Increase and Matching along the Tomography Module at PITZ

focusing, quadrupole, electron, lattice

1144

G. Kourkafas, P. Boonpornprasert, J.D. Good, M. Groß, I.I. Isaev, D.K. Kalantaryan, M. Khojoyan, M. Krasilnikov, D. Malyutin, B. Marchetti, D. Melkumyan, M. Otevřel, T. Rublack, F. Stephan, G. Vashchenko
DESY Zeuthen, Zeuthen, Germany
G. Asova
INRNE, Sofia, Bulgaria
G. Pathak
Uni HH, Hamburg, Germany

The Photo Injector Test facility at DESY, Zeuthen site (PITZ), focuses on testing, characterizing and optimizing high brightness electron sources for free electron lasers. PITZ is equipped with a number of transverse emittance measurement stations, among which is the Phase Space Tomography (PST) module. A PST measurement requires a specific transport along the tomography lattice, which ideally rotates the beam in the normalized transverse phase space by 180 degrees in equidistant steps. A preceding matching section is used to provide an injection scheme that delivers the necessary beam parameters for the design transport along the tomography lattice. The high charge density and moderate energy of the electron bunch at PITZ contribute to significant space-charge forces which lead to emittance growth and consequent mismatches of the design parameters. This article presents and evaluates measurements of the emittance increase along the matching section of a 1 nC beam at 22 MeV/c under different focusing schemes.

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TUPRO052

Study a ‘Sum’ Linear Coupling Resonance for J-PARC Main Ring: Observations and Simulations

resonance, operation, injection, coupling

1147

A.Y. Molodozhentsev, S. Igarashi
KEK, Ibaraki, Japan
Y. Sato, J. Takano
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

J-PARC Main Ring should deliver a high-power proton beam to neutrino experiments with limited particle losses. To meet this requirement low-order machine resonances have to be compensated. The linear coupling resonance Qx+Qy=43 has been identified as the potential source for significant particle losses at the collimator. The resonance compensation scheme has been studied experimentally by using a low intensity beam. To understand this process the simulations have been performed by using the PTC-ORBIT code. The Main Ring model has been developed to reproduce the machine operation including the initial stage of the acceleration. The 6D beam model has been defined to represent the ‘pencil’ beam used for this study. In frame of this report the single and multi particle dynamics will be discussed to understand the results of measurements, performed during RUN44 (November 2012). The results of the long-term tracking for this case will be presented. The obtained results can be used to benchmark the computer modeling the ‘sum’ linear coupling resonance with the experimental results.

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TUPRO056

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

optics, focusing, linac, 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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TUPRO064

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

linac, wakefield, 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, linac, 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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TUPRO068

Commisioning of the 2.4T Multipole Wiggler and the 6.5T Superconducting Wavelength Shifter at the SIAM Photon Source

betatron, optics, storage-ring, operation

1192

P. Sudmuang, S. Klinkhieo, P. Klysubun, S. Kongtawong, S. Krainara, N. Suradet, A. Tong-on
SLRI, Nakhon Ratchasima, Thailand

A 2.4 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS) have been successfully installed and commissioned at Siam Photon Source (SPS). The influence of the two insertion devices on the electron beam dynamic at different operating points have been studied in order to determine the optimal lattice configuration for operation. In this paper, the compensation of the linear optics will be presented, and the commissioning scheme will also be described. In addition, the investigation of the difference between the model and the actual observed machine parameters will be reported in details.

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TUPRO072

Lattice and Component Design for the Front End Test Stand MEBT at RAL

quadrupole, rfq, simulation, lattice

1205

M. Aslaninejad, J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
M.A. Clarke-Gayther, A.P. Letchford, D.C. Plostinar
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) linear accelerator at Rutherford Appleton laboratory (RAL) will accelerate a 60 mA, 2 ms, 50 pps H⁻ beam to 3MeV. The aim of FETS is to demonstrate perfect chopping using a novel 2 stage (fast / slow) chopper scheme. The beam chopper and associated beam dumps are located in the MEBT. Achieving a low emittance-growth under the influence of strong, non-linear space-charge forces in a lattice which has to accommodate the long chopping elements is challenging. The baseline FETS MEBT design is 4.3 m long and contains 7 quadrupoles, 3 rebunching cavities, a fast and slow chopper deflector and two beam dumps. In particle dynamics simulations using a distribution from an RFQ simulation as input, beam loss for the un-chopped beam is below 1% while the chopping efficiency is >99 % in both choppers. The final MEBT lattice chosen for FETS will be presented together with particle tracking results and design details of the beam line components.

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TUPRO074

Emittance Growth due to Multiple Coulomb Scattering in a Linear Collider based on Plasma Wakefield Acceleration

scattering, plasma, acceleration, electron

1211

Ö. Mete, K. Hanahoe, G.X. Xia
UMAN, Manchester, United Kingdom
O. Karamyshev, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M. Labiche
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
M. Wing
UCL, London, United Kingdom

Alternative acceleration technologies are currently under development for cost-effective, robust, compact and efficient solutions. One such technology is plasma wakefield accel- eration, driven by either a charged particle or laser beam. However, the potential issues must be studied in detail. In this paper, the emittance growth of the witness beam through elastic scattering from gaseous media is derived. The model is compared with the numerical studies.

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TUPRO092

Magnetic-field Variable Permanent Dipole Magnet for Future Light Sources

permanent-magnet, dipole, simulation, operation

1253

T. Watanabe, K. Fukami, T. Nakanishi, S. Sasaki
JASRI/SPring-8, Hyogo, Japan

Permanent dipole magnets with variable magnetic field have been designed, fabricated, and tested at SPring-8. Permanent magnets can be advantageous over electromagnets in terms of reliability, stability and compactness in addition to the small power consumption. No unexpected down of an accelerator due to power supply failure is supposed to happen. There is no cooling water flow that can induce a fluctuation of the magnetic field. These features may become important for future light sources, where a very reliable, stable, and compact ring is required. In addition, the power consumption is now one of the most important issues after the 3.11 disaster in Japan. One of critical issues to realize such a magnet is that a magnetic field has to be tuned. In the future, combined-functioned and longitudinally gradient magnets will play a key role in achieving extremely small emittance. In such a case, changing a gap will not work any more. We have designed and fabricated a permanent dipole magnet of which magnetic field can be tuned without changing the gap. The results of the performance test will be presented and a possibility to apply it for future light sources will be discussed.

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TUPME010

The Physics Programme of next MICE Step IV

scattering, factory, experiment, simulation

1361

J.C. Nugent
University of Glasgow, Glasgow, United Kingdom
V.C. Palladino
INFN-Napoli, Napoli, Italy

Funding: DOE, NSF, STFC, INFN, CHIPP and several others
The International Muon Ionization Cooling Experiment is progressing towards a full demonstration of the feasibility of ionization cooling technology decisive for neutrino physics and muon colliders. Step IV should provide the first precise measurements of emittances and first evidence of cooling. The components required for Step IV, including spectrometer solenoids, muon trackers and absorber-FC (focus coil) modules have been assembled with data collection expected in 2015. The physics programme of this Step will be described in detail, with LiH and a few other promising absorber materials of different shapes.
Abstract presented by the chair of the speaker bureau of the MICE collaboration, that would next select a MICE member to prepare and present the poster

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TUPME011

The Status of the Construction of MICE Step IV

solenoid, experiment, coupling, cavity

1364

P. Snopok
IIT, Chicago, Illinois, USA
E. Overton
Sheffield University, Sheffield, United Kingdom

Funding: DOE, NSF, STFC, INFN, CHIPP and several others
The International Muon Ionization Cooling Experiment will provide the demonstration ionization cooling. The experiment is being built in a series of Steps. Step IV, which consists of a tracking spectrometer upstream and downstream of an absorber/focus-coil (AFC) module will be completed in early in 2015. In this configuration, the emittance of the muon beam upstream and downstream of the absorber will be measured precisely allowing the emittance reduction and the factors that determine the ionization cooling effect to be studied in detail. The AFC module is a 22 liter volume of liquid hydrogen placed inside a superconducting focusing coil. The properties of lithium hydride, and possibly other absorber materials, will also be studied. All the components of Step IV have been manufactured and integration of the experiment in the MICE Hall at the Rutherford Appleton Laboratory is underway. A full study of ionization cooling will be carried out with Step V, which will include a short 201 MHz linac module in which beam transport is achieved with a superconducting “coupling coil”. The status of the preparation of the components of Step V of the experiment will be described briefly.

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TUPME014

Development of Six-dimensional Helical Muon Beam Cooling Channel for Muon Colliders

solenoid, cavity, collider, magnet-design

1373

K. Yonehara
Fermilab, Batavia, Illinois, USA

A six-dimensional (6D) helical muon beam cooling channel (HCC) has been developed for a last decade. The practical HCC lattice parameters were optimized for the cooling performance in theoretical and numerical simulations. The HCC design group has been formed and has begun the machine development to realize the channel. Recent accomplishments and present critical issues are discussed in the presentation.

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TUPME015

Study Cooling Performance in a Helical Cooling Channel for Muon Colliders

simulation, solenoid, collider, plasma

1376

K. Yonehara
Fermilab, Batavia, Illinois, USA

The cooling performance in a six-dimensional helical muon beam cooling channel (HCC) has been studied in various beam lattice parameters. We show that the HCC works with a practical beam parameter.

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TUPME016

Status of the Complete Muon Cooling Channel Design and Simulations

solenoid, collider, simulation, luminosity

1379

C.Y. Yoshikawa, C.M. Ankenbrandt, R.P. Johnson, S.A. Kahn, F. Marhauser
Muons, Inc, Illinois, USA
Y.I. Alexahin, D.V. Neuffer, K. Yonehara
Fermilab, Batavia, Illinois, USA
Y.S. Derbenev, V.S. Morozov, A.V. Sy
JLab, Newport News, Virginia, USA

Funding: Work supported in part by DOE STTR grant DE-SC 0007634.
Muon colliders could provide the most sensitive measurement of the Higgs mass and return the US back to the Energy Frontier. Central to the capabilities of such muon colliders are the cooling channels that provide the extraordinary reduction in emittance required for the precise Higgs mass measurement and increased luminosity for enhanced discovery potential of an Energy Frontier Machine. We present the status of the design and simulation of a complete muon cooling channel that is based on the Helical Cooling Channel (HCC), which operates via continuous emittance exchange to enable the most efficient design.

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TUPME017

Design and Simulation of a Matching System into the Helical Cooling Channel

solenoid, collider, simulation, operation

1382

C.Y. Yoshikawa
MuPlus, Inc., Newport News, Virginia, USA
Y.I. Alexahin, D.V. Neuffer, K. Yonehara
Fermilab, Batavia, Illinois, USA
C.M. Ankenbrandt, R.P. Johnson, S.A. Kahn, F. Marhauser
Muons, Inc, Illinois, USA
Y.S. Derbenev, V.S. Morozov, A.V. Sy
JLab, Newport News, Virginia, USA

Funding: Work supported in part by DOE STTR grant DE-SC 0007634.
Muon colliders could provide the most sensitive measurement of the Higgs mass and return the US back to the Energy Frontier. Central to the capabilities of muon colliders are the cooling channels that provide the extraordinary reduction in emittance required for the precise Higgs mass measurement and increased luminosity for enhanced discovery potential of an Energy Frontier Machine. The Helical Cooling Channel (HCC) is able to achieve such emittance reduction and matching sections within the HCC have been successfully designed in the past with lossless transmission and no emittance growth. However, matching into the HCC from a straight solenoid poses a challenge, since a large emittance beam must cross transition. We elucidate on the challenge and present evaluations of two solutions, along with concepts to integrate the operations of a Charge Separator and match into the HCC.

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TUPME019

Design and Simulation of a High Field - low energy Muon Ionization Cooling Channel

focusing, solenoid, simulation, scattering

1386

H. K. Sayed, J.S. Berg, R.B. Palmer, D. Stratakis
BNL, Upton, Long Island, New York, USA

Muon beams are generated with inherited large transverse and longitudinal emittances. In order to achieve low emittance within the short lifetime of the muons, the only feasible cooling scheme is the ionization cooling. In this study we present a design and simulation of a novel ionization cooling channel. The channel operates at a very strong magnetic fields of 25-30 T with low muon beam energy starting from 66 MeV and decreasing gradually. We study the beam dynamics of such low energy beam in high field region inside and between cooling stages. Key design parameters will be presented and in addition the performance and channel requirements of RF cavities and high field magnets will be presented.

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TUPME020

Complete Six-dimensional Muon Cooling Channel for a Muon Collider

collider, lattice, focusing, solenoid

1389

D. Stratakis, J.S. Berg, R.B. Palmer, H. Witte
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We describe a complete 6D rectilinear cooling scheme for use in a Muon Collider. This scheme uses separate 6D cooling channels for the two signs of particle charge. In each, a channel first reduces the emittance of a train of 21 muon bunches until it becomes possible to merge them into a single bunch, one of each sign. The single bunches are then sent through a second rectilinear channel for further cooling towards the requirements of a Muon Collider. We adopt this approach for a new cooling lattice design for the Muon Collider, and for the first time present a end-to-end simulation. We review key parameters such as the required focusing fields, absorber lengths, cavity frequencies and rf gradients.
*D. Stratakis et al., Phys. Rev. ST AB 16, 091001 (2013).

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TUPME021

Theoretical Framework to Predict Efficiency of Ionization Cooling Lattices

focusing, collider, lattice, betatron

1392

D. Stratakis
BNL, Upton, Long Island, New York, USA
D.V. Neuffer
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Brookhaven Science Associates, LC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Reduction of the 6-dimensional phase-space of a muon beam by 6 orders of magnitude is a key requirement for a Muon Collider. Recently, a 12-stage rectilinear ionization cooling channel has been proposed to achieve that goal. In this paper, we establish the mathematical framework to predict and evaluate the cooling performance of the proposed channel. We predict the system effectiveness, by deriving key lattice parameters such as the lattice quality factor which describes the rate of cooling versus the surviving particles and the longitudinal and effective partition numbers for each stage. Main theoretical findings, such as the equilibrium emittances and effective cooling length, are compared against findings from numerical simulations.

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TUPME024

A hybrid six-dimensional muon cooling channel with gas filled cavities

vacuum, cavity, lattice, simulation

1401

D. Stratakis
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Obtaining the desired micron-scale emittances for a Muon Collider requires transporting the muon beam through long sections of a beam channel containing rf cavities, absorbers, and focusing solenoids. Here we discuss possible implementation of high-pressure gas-filled RF cavities in a 6D ionization cooling channel and some technical issues associated with it. The key idea of our scheme is a hybrid approach that uses high-pressure gas to avoid cavity breakdown, along with discrete LiH absorbers to provide the majority of the energy loss. We show that the channel performs as well as the original vacuum rf channel while potentially avoiding degradation in rf gradient associated with the strong magnetic field in the cooling channel.

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TUPME025

Progress on Low Emittance Tuning for the CLIC Damping Rings

quadrupole, coupling, sextupole, dipole

1404

J. Alabau-Gonzalvo, H. Bartosik, Y. Papaphilippou
CERN, Geneva, Switzerland

In the frame of the CLIC main Damping Ring a study on the sensitivity of the lattice to different sources of misalignment is presented. The minimum equilibrium emittance is simulated and analytically estimated under dipole and quadrupole rolls, and quadrupole and sextupole vertical offsets. The result of this study establishes alignment tolerances to preserve the vertical emittance below the design value (1 pm·rad). Non-linear dynamics studies have been done to determine the dynamic aperture in the presence of misalignments.

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TUPME026

TMCI Thresholds for LHC Single Bunches in the CERN-SPS and Comparison with Simulations

optics, impedance, simulation, kicker

1407

H. Bartosik, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, C. Zannini
CERN, Geneva, Switzerland

At the beginning of 2013 an extensive measurement campaign was carried out at the SPS in order to determine the Transverse Mode Coupling Instability thresholds of LHC-type bunches in a wide range of intensities and longitudinal emittances. The measurements were performed in two different configurations of machine optics (nominal and low gamma transition) with the goal to characterize the differences in behavior and performance. The purpose of this paper is to describe in detail the measurement procedure and results, as well as the comparison of the experimental data with HEADTAIL simulations based on the latest SPS impedance model. Beside the impedances of the resistive wall, the beam position monitors (BPMs), the RF cavities, and the flanges, an advanced model of the impedance of the kicker magnets is included, which are found to play a major role in the definition of the stability region of the LHC-type bunches in the two optics configurations studied.

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TUPME027

Analysis of the Electron Cloud Observations with 25 ns Bunch Spacing at the LHC

dipole, injection, quadrupole, experiment

1410

G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy
G. Arduini, V. Baglin, D. Banfi, H. Bartosik, S.D. Claudet, C.O. Domínguez, J. F. Esteban Müller, G. Iadarola, T. Pieloni, G. Rumolo, E.N. Shaposhnikova, L.J. Tavian, C. Zannini, F. Zimmermann
CERN, Geneva, Switzerland

Electron Cloud (EC) effects have been identified as a major performance limitation for the Large Hadron Collider (LHC) when operating with the nominal bunch spacing of 25 ns. During the LHC Run 1 (2010 - 2013) the luminosity production mainly used beams with 50 ns spacing, while 25 ns beams were only employed for short periods in 2011 and 2012 for test purposes. On these occasions, observables such as pressure rise, heat load in the cold sections as well as clear signatures on bunch-by-bunch emittance blow up, particle loss and energy loss indicated the presence of an EC in a large portion of the LHC. The analysis of the recorded data, together with EC build up simulations, has led to a significant improvement of our understanding of the EC effect in the different components of the LHC. Studies were carried out both at injection energy (450 GeV) and at top energy (4 TeV) aiming at determining the energy dependence of the EC formation and its impact on the quality of the proton beam.

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TUPME028

Flat Bunches in the LHC

impedance, operation, luminosity, synchrotron

1413

E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, J. F. Esteban Müller, T. Mastoridis, G. Papotti, B. Salvant, H. Timko
CERN, Geneva, Switzerland
C.M. Bhat, A.V. Burov
Fermilab, Batavia, Illinois, USA

A high-harmonic RF system that could serve multiple purposes was proposed for the LHC. Possible applications of the second harmonic RF system include beam stabilisation in the longitudinal plane in the absence of wide-band longitudinal feedback and reduction of bunch peak line-density. Apart from other useful features, flat bunches are expected to produce less beam-induced heating at frequencies below 1 GHz, the frequency region critical for some LHC equipment. The latter, however, can also be achieved by de-populating the bunch centre. This was demonstrated during the dedicated machine development session in the LHC using RF phase modulation. In this paper the results of tests with single bunches and nominal LHC beams are presented and the possible use of this technique in LHC operation is discussed.

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TUPME041

The Advanced Superconducting Test Accelerator at Fermilab: Science Program

SRF, electron, linac, 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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TUPME042

Planned High-gradient Flat-beam-driven Dielectric Wakefield Experiments at the Fermilab’s Advanced Superconducting Test Accelerator

acceleration, wakefield, experiment, controls

1451

F. Lemery, D. Mihalcea, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
P. Piot, J. Zhu
Fermilab, Batavia, Illinois, USA
J. Zhu
CAEP/IFP, Mainyang, Sichuan, People's Republic of China

In beam driven dielectric wakefield acceleration (DWA), high-gradient short-wavelength accelerating fields are generally achieved by employing dielectric-lined waveguides (DLWs) with small aperture which constraints the beam sizes. In this paper we investigate the possibility of using a low-energy (50-MeV) flat beams to induce high-gradient wakes in a slab-symmetric DLW. We demonstrate via numerical simulations the possibility to produce axial electric field with peak amplitude close to 0.5 GV/m. Our studies are carried out using the Fermilab's Advanced Superconducting Test Accelerator (ASTA) photoinjector beamline. We finally discuss a possible experiment that could be performed in the ASTA photoinjector and eventually at higher energies.

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TUPME046

3-D Particle-in-cell Simulations for Quasi-phase Matched Direct Laser Electron Acceleration in Density-modulated Plasma Waveguides

electron, laser, plasma, simulation

1463

M.W. Lin
The Pennsylvania State University, University Park, Pennsylvania, USA
I. Jovanovic
Penn State University, University Park, Pennsylvania, USA

Funding: This work is supported by the Defense Threat Reduction Agency through contract HDTRA1-10-1-0034.
Quasi-phase matched (QPM) direct laser acceleration (DLA) of electrons can be realized with guided, radially polarized laser pulses in density-modulated plasma waveguides*,**. A 3-D particle-in-cell (PIC) simulation model has been developed to study the scheme in which an electron bunch from a laser wakefield accelerator (LWFA) is injected into a plasma waveguide for the second-stage DLA to higher energies. In addition to being driven directly by the laser field, the electrons also experience the laser pondermotive force and the electrostatic force from the excited plasma waves. The results lead to better understanding of the interactions between the electron bunch, the laser pulse and the background plasma. Selected bunch lengths, bunch sizes and time delays with respect to the laser pulse are assigned for the injected electrons in a series of simulations. The energy spectrum and emittance of the accelerated electron bunch vary depending on those initial conditions, and they can be chosen to optimize the DLA performance.
* P. Serafim, et al., IEEE Trans. Plasma Sci. 28, 1155 (2000).
** M. -W. Lin and I. Jovanovic, Phys. Plasmas 19, 113104 (2012).

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TUPME059

Longitudinal Bunch Shaping with a Double Dogleg based Emittance Exchange Beam Line

space-charge, controls, experiment, cavity

1506

G. Ha, M.E. Conde, W. Gai, C.-J. Jing, K.-J. Kim, J.G. Power, A. Zholents
ANL, Argonne, Illinois, USA
M.-H. Cho, G. Ha, W. Namkung
POSTECH, Pohang, Kyungbuk, Republic of Korea
C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA

Funding: Work supported by High Energy Physics, Office of Science, US DOE.
A new program is under development at Argonne National Laboratory (ANL) to use an emittance exchange (EEX) beamline to produce longitudinally shaped electron bunches. While the ultimate goal is to generate triangular shapes for high transformer ratio wakefield acceleration we are also exploring, in general, the capability of the double dogleg EEX beamline to control the bunch shape. We are studying effects that degrade the quality of the longitudinal current profile including: non-uniform particle distribution, emittance, the deflecting cavity thick-lens effect, 2nd order effects, space charge effects and coherent synchrotron radiation effects. We will present the double dogleg EEX beamline layout and the diagnostic design as well as give a progress report on the experimental status of the program.

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TUPRI004

The Design and Implementation of The Radiation Monitors for the Protection of the MICE Tracker Detectors

radiation, detector, experiment, electron

1559

M.A. Uchida, C. Hunt, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

A radiation monitor will be required for the Muon Ionisation Cooling experiment (MICE) beyond Step IV, when the RF cavities are installed. The role of the radiation monitors will be to protect the particle tracking detectors (Trackers) from dangerous levels of RF dark currents and the as- sociated photon fluxes that could potentially be produced in the RF cavities. If such levels of radiation should occur the radiation monitor will ensure that the radiation shields (shutters) are closed thereby protecting the Tracker modules. The radiation monitor will be positioned on these radiation shields and will monitor x-rays, gamma-rays and electrons up to a few MeV. It is expected that the spectrum will peak at very low energies, since the peak voltage across the cavities is 8 MV/m and so the maximum energy that an electron could gain is 12 MeV (maximally accelerated from all four RF cavities). The design, positioning and expected sensitivity of the radiation monitors will be described here along with their readout and inclusion into the MICE interlocking systems. The schedule for the work and progress so far will also be presented.

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TUPRI017

Artificial Collisions, Entropy and Emittance Growth in Computer Simulations of Intense Beams

space-charge, simulation, focusing, scattering

1588

O. Boine-Frankenheim, I. Hofmann, J. Struckmeier
GSI, Darmstadt, Germany

During particle tracking with self-consistent space charge artificial collision between the macro-particles lead to diffusion-like, numerical effects. The artificial collisions generate a stochastic noise spectrum. As a consequence the entropy and the emittance of the particle beam can growth along periodic focusing structures. The growth rates depend on the number of simulation macro-particles and on the space charge tune shifts. For long-term tracking studies the numerical diffusion can lead to incorrect beam loss predictions. In our study we present analytical prediction for the numerical friction and diffusion in 2D and 3D simulations. For simple focusing structures with derive a relation between the friction coefficient and the entropy growth. The scaling of the friction coefficient with the macro-particle number and the space charge tune shift is obtained from 2D and 3D simulations and compared to the analytic predictions.

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TUPRI020

Study of Electron Cloud Effects in SuperKEKB

electron, damping, simulation, radiation

1597

K. Ohmi, D. Zhou
KEK, Ibaraki, Japan

In SuperKEKB, high beta section exists in the interaction region. Fast head-tail instability and incoherent emittance growth due to electron cloud are enhanced in the high beta section. Especially high beta sections are located every betatron phase advance pi. Nonlinear force due to electron cloud is coherently accumulated. Incoherent eminence growth dominates.

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TUPRI022

Beam-Beam Studies in LHC- Beam Loss and Bunch Shortening

simulation, resonance, synchrotron, luminosity

1603

K. Ohmi
KEK, Ibaraki, Japan

In Hadron colliders, luminosity degrade various mechanism. Beam-beam related emittance growth is caused by resonances induced by crossing angle. Tune spread due to chromaticity enhances the resonances effect. A bunch shortening phenomenon related to beam-beam interaction has been observed in LHC. The bunch length has an anti-correlation with transverse emittance. This phenomenon has been studied using a weak-strong beam-beam simulation (BBWS code).

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TUPRI025

Interplay of Touschek Scattering, Intrabeam Scattering, and RF Cavities in Ultralow-emittance Storage Rings

lattice, storage-ring, scattering, coupling

1612

S.C. Leemann
MAX-lab, Lund, Sweden

When it goes into operation in 2016, the MAX IV 3 GeV storage ring will be the first ultralow-emittance storage ring based on a multibend achromat lattice. These lattices make use of a large number of weak bending magnets which considerably reduces the amount of power radiated in the dipoles in comparison to power radiated from insertion devices. Therefore parameters such as emittance, energy spread, and radiated power are no longer constant during a typical user shift. Since the charge per bunch is usually high, intrabeam scattering (IBS) becomes very strong creating a dependence of emittance on stored current. Since the bunch length can vary as insertion device gaps change, the emittance blow-up from IBS is not constant either. Therefore, the emittance, bunch length, and hence the resulting Touschek lifetime have to be calculated in a self-consistent fashion taking into account the bare lattice, RF cavity settings, bunch charge, and gap settings. This paper demonstrates the intricate interplay between transverse emittance (insertion devices, emittance coupling), longitudinal emittance (tuning of main cavities as well as harmonic Landau cavities), and choice of stored current.

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TUPRI026

MAX IV Emittance Reduction and Brightness Improvement

optics, storage-ring, brightness, lattice

1615

S.C. Leemann, M. Eriksson
MAX-lab, Lund, Sweden

With MAX IV construction well underway and storage ring commissioning expected to commence in July 2015, first studies have been launched to improve the optics of the MAX IV 3 GeV storage ring with the goal of further reducing the emittance from the baseline design (328 pm rad) towards 150 pm rad while improving the matching of the electron beam to insertion devices to further improve the resulting photon brightness. We report on progress in the development of this new optics taking into account the strong impact from intrabeam scattering and insertion devices on the resulting equilibrium emittance. We present initial results and sketch a path towards a first MAX IV upgrade.

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TUPRI027

Detailed Magnetic Model Simulations of the H⁻ Injection Chicane Magnets for the CERN PS Booster Upgrade, including Eddy Currents, and Influence on Beam Dynamics

injection, simulation, vacuum, space-charge

1618

E. Benedetto, B. Balhan, J. Borburgh, C. Carli, V. Forte, M. Martini
CERN, Geneva, Switzerland
V. Forte
Université Blaise Pascal, Clermont-Ferrand, France

The CERN PS Booster will be upgraded with an H⁻ injection system. The chicane magnets for the injection bump ramp-down in 5 ms and generate eddy currents in the inconel vacuum chamber which perturb the homogeneity of the magnetic field. The multipolar field components are extracted from 3D OPERA simulations and are included in the lattice model. The beta-beating correction is computed all along the ramp and complete tracking simulations including space-charge are performed to evaluate the impact of these perturbations and their correction.

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TUPRI028

Review of Rest Gas Interaction at Very Low Energies applied to the Extra Low ENergy Antiproton ring ELENA

scattering, antiproton, ion, electron

1621

C. Carli, T.L. Rijoff
CERN, Geneva, Switzerland
O. Karamyshev, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

The Extremely Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which shall be constructed at CERN to decelerate antiprotons to energies as low as 100 keV. Scattering of beam particles on rest gas molecules may have a detrimental effect at such low energies and leads to stringent vacuum requirements. Within this contribution scattering of the stored beam on rest gas molecules is discussed for very low beam energies. It is important to carefully distinguish between antiprotons scattered out of the acceptance and lost, and those remaining inside the aperture to avoid overestimation of emittance blow-up. Furthermore, many antiprotons do not interact at all during the time they are stored in ELENA and hence this is not a multiple scattering process

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TUPRI035

Measurement of Beam Size in Intrabeam Scattering Dominated Beams at Various Energies at CesrTA

scattering, storage-ring, electron, photon

1635

M. P. Ehrlichman, K.J. Blaser, A. Chatterjee, W. Hartung, B.K. Heltsley, D.P. Peterson, D. L. Rubin, D. Sagan, J.P. Shanks, S. Wang
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: This research was supported by NSF and DOE contracts PHY-0734867, PHY-1002467, PHYS-1068662, DE-FC02-08ER41538, DE-SC0006505.
Recent reports from CesrTA have shown measurement and calculation of beam size versus current in CesrTA beams at 2.1 GeV. Here, the effect of changing the energy of IBS-dominated beams is reported. IBS growth rates have roughly a γ^-3 dependence. Measurements at 1.8, 2.1, 2.3, and 2.5 GeV are shown and compared with predictions from IBS theory.

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TUPRI044

Investigation of Microbunching-instability in BERLinPro

electron, simulation, linac, space-charge

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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TUPRI053

Transverse Beam Instabilities in the MAX IV 3 GeV ring

impedance, damping, operation, storage-ring

1689

G. Skripka, P.F. Tavares
MAX-lab, Lund, Sweden
M. Klein, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

Collective effects in MAX IV 3 GeV storage ring are strongly enhanced by the combination of low emittance, high current and small effective aperture. Three passive harmonic cavities (HC) are introduced to lengthen the bunches, by which beam stabilization is anticipated via decoupling to high frequency wakes, along with Landau damping. The role of the ransverse impedance budget of the MAX IV 3 GeV storage ring as a source of collective beam instabilities was determined. With the help of the macroparticle multi-bunch tracking code mbtrack that directly uses the former as input, we studied the influence of geometric and resistive wall impedance in both transverse planes, as well as that of chromaticity shifting. A fully dynamic treatment of the passive harmonic cavities developed for this study allowed us to evaluate their effectiveness under varying beam conditions.

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TUPRI056

Beam Measurements of the LHC Impedance and Validation of the Impedance Model

impedance, damping, synchrotron, simulation

1698

J.F. Esteban Müller, T. Argyropoulos, T. Bohl, N. Mounet, E.N. Shaposhnikova, H. Timko
CERN, Geneva, Switzerland

Different measurements of the longitudinal impedance of the LHC done with single bunches with various intensities and longitudinal emittances during measurement sessions in 2011-2012 are compared with particle simulations based on the existing LHC impedance model. The very low reactive impedance of the LHC, with Im(Z/n) around 0.1 Ohm, is not easy to measure. The most sensitive observation is the loss of Landau damping during acceleration, which shows at which energy bunches become unstable depending on their parameters. In addition, the synchrotron frequency shift due to the reactive impedance was estimated following two methods. Firstly, it was obtained from the peak-detected Schottky spectrum. Secondly, a sine modulation in the RF phase was applied to the bunches with different intensities and the modulation frequency was scanned. In both cases, the synchrotron frequency shift was of the order of the measurement precision.

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TUPRI080

Emittance Optimisation in the Drive Beam Recombination Complex at CTF3

feedback, linac, 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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TUPRI083

A Fast Optics Correction for the Diamond Storage Ring

optics, quadrupole, storage-ring, feedback

1763

I.P.S. Martin, M.G. Abbott, R. Bartolini, M.J. Furseman, G. Rehm
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Since March 2013, the Diamond storage ring has been operated with a target vertical emittance of 8 pm.rad. This condition is achieved by first applying a LOCO* optics correction with IDs set to their typical gaps, then offsetting the skew quadrupole magnets in order to increase the vertical emittance again to the desired value. Whilst a feedback application** is able to stabilise the vertical emittance during ID gap and phase changes in the short to medium term, regular applications of LOCO are still required to maintain good coupling control in the longer term. In this paper we describe measures taken to speed up the optics correction procedure, including a fast orbit response matrix measurement, a reduction of the number of magnets used to measure the data, and a distribution of the LOCO calculations to run in parallel.
* J. Safranek, Nucl. Inst. Meth. A, 338, (1997)
** I.P.S. Martin, et al., IPAC 2013, MOPEA071, www. JACoW.org

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TUPRI090

Linac Alignment for SuperKEKB Injector

alignment, laser, linac, 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, linac, 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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WEZA01

Towards an International Linear Collider: Experiments at ATF2

optics, sextupole, quadrupole, feedback

1867

K. Kubo
KEK, Ibaraki, Japan

For linear colliders, realizing extremely small and stable beam is essentially important. At ILC (International Linear Collider), designed vertical beam size and required position stability at the interaction point is nanometer level. In ATF (Accelerator Test Facility) at KEK, study of the final focus system has been performed using small emittance beams extracted from the damping ring. The project is called ATF2. The ATF2 beam line is designed as a prototype of the final focus system of ILC, with basically the same optics, similar beam energy spread, natural chromaticity and tolerances of magnetic field errors. Its design, construction and operation have been performed as an international collaboration. We have demonstrated the local chromatic correction method, which will be used in ILC, and observed the vertical beam size about 55 nm. Test and demonstration of intra-pulse orbit feedback has been successfully performed in the middle of the ATF2 beam line. For demonstration of nm level stable beam, high resolution beam position monitors were installed around the focal point. Here, we report our achievement, status and future plans.

Slides WEZA01 [1.453 MB]

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WEPRO007

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

electron, cavity, gun, linac

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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WEPRO009

A New Booster Synchrotron for the Sirius Project

booster, injection, lattice, sextupole

1959

L. Liu, X.R. Resende, A.R.D. Rodrigues, F. H. de Sá
LNLS, Campinas, Brazil

The design for the Sirius full energy booster has been modified after the decision to change the storage ring lattice from TBA to 5BA in July 2012. In the new design the booster is concentric with the storage ring and shares the same tunnel. The achieved emittance of 3.7 nm.rad at 3 GeV for this large booster (496.8 m circumference) is better matched to the 5BA storage ring emittance of 0.28 nm.rad. Good nonlinear behaviour and efficient closed orbit correction in the presence of realistic errors are shown. Injection and extraction schemes and eddy current effects during ramping are also discussed.

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WEPRO015

RF Injector Beam Dynamics Optimization for LCLS-II

simulation, linac, 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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WEPRO019

Comparison of the NSLS-II Linac Model to Measurements

linac, cathode, 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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WEPRO028

A Robinson Wiggler Proposal for the Metrology Light Source

wiggler, damping, radiation, synchrotron

2001

T. Goetsch, J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung and Land Berlin.
The Metrology Light Source (MLS), situated in Berlin (Germany) is owned by the Physikalisch-Technische Bundesanstalt and was built / is operated by the Helmholtz-Zentrum Berlin. It is an electron storage ring operating from 10⁵ MeV to 630 MeV. The MLS serves as the national primary source standard from the near infrared to the extreme ultraviolet spectral region *. Users of synchrotron radiation demand an improved lifetime which is Touschek dominated at the MLS. A possible solution to meet this demand is to lengthen the electron bunches. By installing a Robinson Wiggler (RW), damping effects can be transferred from the longitudinal to the horizontal plane **,***, thereby increasing the energy spread and reducing the horizontal emittance. By varying the energy spread, the bunch length can be increased and thus the scattering rate decreased, resulting in an improved lifetime. According to preliminary estimations a considerable increase in lifetime seems achievable, while preserving the source size.
* R. Klein et al., Phys. Rev. ST-AB 11, 110701, 2008
** K. W. Robinson, Radiation effects in circular electron accelerators, 1958.
*** H. Abualrob et al., MOPPP062, IPAC2012, New Orleans, 2012

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WEPRO042

Damping Wiggler with Tapered Period

wiggler, lattice, damping, radiation

2038

K. Karyukina
BINP, Novosibirsk, Russia
A.V. Bogomyagkov, E.B. Levichev
BINP SB RAS, Novosibirsk, Russia

Strong-field short-period wigglers installed in electron storage ring increase the radiation damping integral I2 and either increase or decrease the I5 integral responsible for quantum excitation. In case of the I5 integral decreasing, the beam emittance can be substantially reduced. In the paper we discuss additional reduction of I5 by applying of the longitudinal modulation of the wiggler period (tapering).

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WEPRO046

Beam Dynamic Effect of Multi-period Robinson Wiggler in Taiwan Photon Source

wiggler, dipole, damping, storage-ring

2044

C.W. Huang
NTHU, Hsinchu, Taiwan
C.-S. Hwang
NSRRC, Hsinchu, Taiwan
S.-Y. Lee
IUCEEM, Bloomington, Indiana, USA

Robinson wiggler is a special insertion device that can be used to decrease natural emittance of the Taiwan Photon Source (TPS) storage ring. There are four poles in one set of Robinson Wiggler and each pole has combined with dipole and quadrupole field strength. The dipole field strength multiply quardupole field strength in each pole should be negative. This Robinson wiggler can change damping partition number and then affect the emittance. This study will evaluate practicability of reducing the emittance of TPS storage ring by muti-period Robinson wiggler and will be installed in the 7 m long-straight section. One period of the traditional Robinson Wiggler include four poles with different field polarity. In the same length, the mult-period Robinson Wiggler have many period in one set of Robinson Wiggler that is different from the traditional Robinson wiggler. Due to the traditional Robinson wiggler can not be effective to improve emittance in TPS storage ring (the efficiency is only 7%). So we adopt to use muti-period Robinson wiggler, the efficiency can be up to 37%, and the linear matching result is better than one period Robinson Wiggler.

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WEPRO055

Development of a Quasi 3-D Ellipsoidal Photo Cathode Laser System for PITZ

laser, electron, simulation, cathode

2069

T. Rublack, M. Khojoyan, M. Krasilnikov, F. Stephan
DESY Zeuthen, Zeuthen, Germany
A.V. Andrianov, E. Gacheva, E. Khazanov, A. Poteomkin, V. Zelenogorsky
IAP/RAS, Nizhny Novgorod, Russia
I. Hartl, S. Schreiber
DESY, Hamburg, Germany
E. Syresin
JINR, Dubna, Moscow Region, Russia

Funding: Funded by the German Federal Ministry of Education and Research (BMBF) project 05K10CHE in the framework of the German-Russian collaboration "Development and Use of Accelerator-Based Photon Sources".
3-D ellipsoidal photo cathode laser pulses are considered as the next step in optimization of photo injectors required for a successful operation of linac based free electron lasers. Significant improvements in electron beam emittance obtained from the beam dynamics simulations using such laser pulses compared to the conventional cylindrical pulses motivated the experimental studies in order to develop a laser system for quasi 3-D ellipsoidal pulses. The Institute of Applied Physics (Nizhny Novgorod, Russia) in collaboration with the Joint Institute of Nuclear Research (Dubna, Russia) and the Photo Injector Test facility at DESY, Zeuthen site (PITZ) is developing such a photo cathode laser system. Experimental tests of the laser system with photoelectron beam production are planned at PITZ. The laser pulse shaping is realized using the spatial light modulator technique. The laser system is capable of pulse train generation. First cross-correlation measurements were done demonstrating in principle the ability to generate and measure quasi ellipsoidal laser pulses. In this contribution the overall set-up, working principle and the actual progress of the development will be reported.

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WEPRO057

Effect of the Electron Beam Emittance on the ILSF Radiation of Sources and Beamline Design

photon, undulator, brilliance, electron

2075

A. Gholampour, S. Amiri, H. Ghasem, H. Khosroabadi, J. Rahighi
ILSF, Tehran, Iran
H. Ghasem, M. Lamehi Rashti, J. Rahighi
IPM, Tehran, Iran

At the Iranian Light Source Facility (ILSF), two different storage ring options are being studied. The designs differ in emittance. In the first option the calculated emittance is 3.278 nm-rad whereas for the second option emittance is 0.937 nm-rad. In this paper the electron beam emittance effects on the source radiation properties from bending magnet, wiggler and undulator, X-ray optics and the beamline design are carefully studied. The present calculations demonstrate that in the case of 0.937 nm-rad brilliance of undulator is increased by a factor of about 5. For bending magnet, flux is reduced almost 1 order of magnitude for hard x-ray regime. Because of smaller size of the source for undulator at the case of 0.937 nm-rad, we can achieve to a smaller spot size and higher resolution with easier focusing systems and usual kind of monochromator than the emittance of 3.278 nm-rad and for the bending magnet hard x-ray beamline, size of the mirrors reduced 30% in the 0.937 nm-rad emittance case, so its result is shorter mirror, low cost and perhaps more challengeable heat load.

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WEPRO070

Overcoming the Horizontal Depolarizing Resonance in the Brookhaven AGS

resonance, polarization, timing, betatron

2112

H. Huang, L. Ahrens, M. Bai, M. Blaskiewicz, K.A. Brown, R. Connolly, Y. Dutheil, W. Fischer, C.J. Gardner, J.W. Glenn, T. Hayes, F. Méot, A. Poblaguev, V.H. Ranjbar, T. Roser, V. Schoefer, K.S. Smith, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno, S.Y. Zhang
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.
Imperfection and vertical intrinsic depolarizing resonances have been overcome by the two partial Siberian snakes in the AGS. The relatively weak but numerous horizontal resonances are the main source of polarization loss in the AGS. A pair of horizontal quads have been used to overcome these weak resonances. This technique needs very accurate jump timing. Fast roll-over magnet cycle has been used and it improves the polarization transmission efficiency near extraction when acceleration usually is slowing down. Emittance preservation is also important to mitigate polarization loss. Recent experimental results including jump quad timing and emittance preservation are presented in this paper.

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WEPRO083

Implementation of a Superconducting Electron Beam Ion Source into the HIT Ion Source Test Bench

ion, rfq, ion-source, ECRIS

2153

E. Ritter, A. Silze, G.H. Zschornack
DREEBIT GmbH, Dresden, Germany
R. Cee, Th. Haberer, A. Peters, T.W. Winkelmann
HIT, Heidelberg, Germany
G. Zschornack
TU Dresden, Dresden, Germany

Cancer therapy with light heavy ions is now a well proven technology. Almost all facilities are running Electron Cyclotron Resonance Ion Sources (ECRIS) to produce carbon ions and protons as well. In the 1990’s the idea of using a Electron Beam Ion Source was proposed (EBIS) [1]. Some proof of principle measurements were carried out [2] but the application of EBIS ion sources in radiation facilities has not been established. We present results from the implementation of a superconducting EBIS, the Dresden EBIS-SC, at an RFQ accelerator at the testbench of the Heidelberg Ion Therapy Center (HIT). First results from C 4+ ions produced by the Dresden EBIS-SC [3] and injection in an RFQ accelerator at the HIT testbench are shown. Furthermore, emittance measurements as well as investigations of the ion energy and the transmission through the RFQ were done. The emittance of the EBIS source is lower by a factor of nine compared to an ECRIS, which improves the transmission through the RFQ. With the current setup the ion output from the EBIS-SC is lower by a factor of 7 compared to an ECRIS to fulfill the requirements of the highest irradiation level. Further improvements are discussed.
* erik.ritter@dreebit.com

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WEPRO088

Design of Beam Transport Lines for Radioisotope Production Systems in NIRS Cyclotron Facility

target, beam-transport, cyclotron, proton

2162

K. Katagiri, S. Hojo, M. Nakao, A. Noda, K. Noda, A. Sugiura, K. Suzuki
NIRS, Chiba-shi, Japan

A new beam transport and a irradiation system were designed for radionuclides production with heat damageable targets. The incident beam is swept along a circle on the irradiation target with fast steering magnets. The width and the sweeping radius of the incident beams were optimized to achieve high production efficiency and avoid the heat damages. Based on those optimized parameters, beam optics of the new beam transport lines was optimized. To obtain initial conditions for the optical calculations, the beam emittance and the Twiss parameters were measured at the upper stream of the new beam transport lines. In this paper, we present the results of the calculations and the optimized beam transport lines.

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WEPRO103

Femtosecond Time-resolved Transmission Electron Microscopy using an RF Gun

electron, gun, laser, cathode

2205

J. Yang, M. Gohdo, K. Kan, T. Kondoh, K. Tanimura, Y. Yoshida
ISIR, Osaka, Japan
J. Urakawa
KEK, Ibaraki, Japan

The first prototype of RF gun based relativistic-energy electron microscopy has been constructed at Osaka University to study ultrafast structural dynamic processes in matter. The RF gun driven by a femtosecond laser has generated a 100-fs-pulse MeV electron beam with emittance of 0.1 mm-mrad and energy spread of 10^-4. Both the electron diffraction and image measurements have been succeeded in the prototype using the femtosecond electron beam. In the diffraction measurement, an excellent quality of diffraction pattern was acquired with electron number of 10⁶. The single-shot measurement is available in the prototype. In the image measurement, the TEM image was acquired with a total electron number of 10⁸. The magnification was 3,000 times. In the next step, we will reduce further the emittance to increase the beam brightness on the sample, and then improve the spatial resolution to <10 nm.

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WEPRO114

SALOME: An Accelerator for the Practical Course in Accelerator Physics

cathode, quadrupole, electron, experiment

2235

V. Miltchev, D. Riebesehl, J. Roßbach, M. Trunk
Uni HH, Hamburg, Germany
O. Stein
CERN, Geneva, Switzerland

SALOME (Simple Accelerator for Learning Optics and the Manipulation of Electrons) is a short low energy linear electron accelerator built by the University of Hamburg. The goal of this project is to give the students the possibility to obtain hands-on experience with the basics of accelerator physics. In this contribution the layout of the device will be presented. The most important components of the accelerator will be discussed and an overview of the planned demonstration experiments will be given.

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WEPME060

Yb DOPED HIGH-ENERGY UV ULTRAFAST LASER FOR AREAL FACILITY

laser, electron, gun, alignment

2412

A. Lorsabyan, A.A. Gevorgyan, B. Grigoryan, A.S. Simonyan
CANDLE SRI, Yerevan, Armenia
V. Clet, A. Courjaud
Amplitude Systemes, Pessac, France
T.K. Sargsyan
LT-PYRKAL cjsc, Yerevan, Armenia

For electron generation from photocathode the new laser system was developed for the AREAL linear accelerator laboratory. Besides generating electrons using the laser, we plan to provide a laser beam for other experimental stations running in parallel. The performance and capabilities of the laser system including operating frequency, electron generation in multi-bunch regime and other advantages are presented. The outlooks and steps for further upgrade are discussed.

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WEPME061

Ytterbium Fiber and Disk Laser of RF Gun for SuperKEKB

laser, gun, cavity, background

2415

X. Zhou, T. Natsui, Y. Ogawa, M. Yoshida
KEK, Ibaraki, Japan

For SuperKEKB project, the electron beams with a charge of 5 nC and a normalized emittance of 10 μm are expected to be generated in the photocathode RF gun at the injector linac. An ytterbium (Yb)-doped laser system with a center wavelength of 259 nm and a pulse width of 30 ps is employed to obtain high peak energy pulses. Although, the pulse repetition of 25 Hz with double-bunch is required, more than 5 nC electron with single-bunch has so far been generated in the 2 Hz.

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WEPME080

Optimization of Quadripolar Field Production for Electrostatic Ion Beam Focusing

quadrupole, focusing, beam-losses, radioactivity

2468

F.R. Osswald, E. Bouquerel, D. Boutin
IPHC, Strasbourg Cedex 2, France
W. Beeckman, J.L. Lancelot
Sigmaphi, Vannes, France

Recent calculations concerning the shape of the quadrupole used as a focusing lens revealed a potential progress margin especially for short devices*. The main issues of the paper are related with the improvement of the performances of some standard quadrupolar focusing equipments considered here with an electrostatic technology i.e. the influence on the beam transmission, aberrations limitation, and reduction of beam losses. The joint research and development programme between a laboratory and the industry are expected to enable technology transfer, design optimization and cost reduction.
* Quadrupole shapes, R. Baartman, PRST-AB 15, 074002 (2012)

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WEPRI007

Booster Cavity and Fundamental Power Coupler Design Issues for BERLinPro

cavity, booster, SRF, coupling

2490

A. Neumann, M. Abo-Bakr, W. Anders, A. Burrill, V.F. Khan, J. Knobloch, S. Wesch
HZB, Berlin, Germany

Funding: Work supported by German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association
HZB has started building the 50MeV, 100mA demonstrator energy-recovery-linac (ERL) facility BERLinPro. The high power injector system needs to deliver this beam at 6.5MeV by combining the energy gain of a 1.4 cell SRF photo-injector and three Cornell style 2-cell booster cavities. One booster cavity will be operated at zero-crossing for bunch energy chirping. Thus two booster cavities have to deliver 2MV each requiring a strong coupling with a loaded Q of 10⁵. To house the two envisaged KEK fundamental power couplers (FPC) with the cavity, the geometry was slightly modified. Further, to increase coupling and reduce transverse kick effects to the beam, a ”golf-tee” antenna tip was designed. This paper summarizes the SRF challenges for the booster cavities, the operational conditions and the modification to the KEK couplers, including tracking calculations to estimate the coupler kick effect to higher order.

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WEPRI100

Magnetic Design Constraints of Helical Solenoids

dipole, solenoid, simulation, beam-cooling

2731

M.L. Lopes, S. Krave, J.C. Tompkins, K. Yonehara
Fermilab, Batavia, Illinois, USA
G. Flanagan, S.A. Kahn
Muons, Inc, Illinois, USA
K.E. Melconian
Texas A&M University, College Station, Texas, USA

Helical solenoids have been proposed as an option for a Helical Cooling Channel for muons in a proposed Muon Collider. Helical solenoids can provide the required three main field components: solenoidal, helical dipole, and a helical gradient. In general terms, the last two are a function of many geometric parameters: coil aperture, coil radial and longitudinal dimensions, helix period and orbit radius. In this paper, we present design studies of a Helical Solenoid, addressing the geometric tunability limits and auxiliary correction system.

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WEPRI103

Magnet Design for a Six-dimensional Rectilinear Cooling Channel - Feasibility Study

solenoid, dipole, simulation, collider

2740

H. Witte, J.S. Berg, R.B. Palmer, D. Stratakis
BNL, Upton, Long Island, New York, USA
F. Borgnolutti
LBNL, Berkeley, California, USA

Funding: Work supported by Brookhaven Science Associates, LC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
An essential part of a potential future muon collider is ionization cooling, which is required to reduce the emittance of the muon beam. A new scheme has recently been proposed which in simulations shows an improved performance in terms of cooling efficiency and transmitted muons. The lattice of this cooling channel consists of 12 stages, each of which requires different superconducting solenoids. The most challenging stage is the last one, where the solenoids are expected to deliver 15.1T in a bore of ~4.5 cm. This paper discusses the feasibility of the solenoids for the last stage of this lattice.

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THOBA02

Status of the Emittance Transfer Experiment Emtex

solenoid, quadrupole, coupling, injection

2798

M.T. Maier, L. Groening, C. Mühle, I. Pschorn, P. Rottländer, C. Will, C. Xiao
GSI, Darmstadt, Germany
M. Chung
Fermilab, Batavia, Illinois, USA

In order to improve the injection efficiency of the round UNILAC heavy ion beam into the asymmetric acceptance of the SIS18 it would be of great advantage to decrease the horizontal emittance by a so called emittance transfer to the vertical plane. In this contribution the present status of the emittance transfer experiment EMTEX at GSI will be reported. A short introduction about the theoretical background of the technique will be given, while the main part is dedicated to the practical solutions setting up a test beam line at GSI. Finally, the results of a first commissioning beam time will be presented. The scheduled beam time to apply the emittance transfer technique foreseen in spring 2014 had to be shifted to calendar week 26 in 2014, just after this conference, as some components have not been delivered in time by the contractor. The results and comparison to the theoretical predictions you may find in later publications.

Slides THOBA02 [1.928 MB]

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THPRO011

Investigation of the Coherence Properties of the Radiation at FLASH

radiation, electron, FEL, undulator

2879

E. Schneidmiller, M.V. Yurkov
DESY, Hamburg, Germany

We present the results of the studies of coherence properties of the radiation from FLASH for fundamental harmonic and higher odd harmonics. General overview of the parameter space is performed including peak current, emittance, and external focusing. The results of our studies show that present configuration of FLASH free electron laser is not optimal for providing ultimate quality of the output radiation. We find that the physical origin of the problem is mode degeneration. The way for improving quality of the radiation is proposed.

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THPRO020

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

linac, lattice, FEL, simulation

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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THPRO029

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

linac, gun, dipole, bunching

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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THPRO043

Studies on the Application of the 3D Ellipsoidal Cathode Laser Pulses at PITZ

laser, booster, electron, flattop

2958

M. Khojoyan, M. Krasilnikov, F. Stephan
DESY Zeuthen, Zeuthen, Germany

Funding: The work is funded by the German federal Ministry of education and Research, project 05K10CHE “development and experimental test of a laser system for producing quasi 3D ellipsoidal laser pulses”.
The Photo Injector Test facility at DESY, Zeuthen Site (PITZ) characterizes and optimizes high brightness electron sources for FLASH and the European XFEL. At nominal conditions the electron bunches are created from a photocathode laser with flat-top temporal distribution and sharp rise and fall times. Beam dynamics simulations using a 3D ellipsoidal cathode laser shape yielded to a significant improvement of the electron beam quality compared to the traditionally used cylindrically shaped beams. The 3D ellipsoidal laser system is under development at the Institute of Applied Physics (IAP) and will be used at PITZ soon, to create high quality electron beams. The recent studies of electron beam simulations at PITZ have been devoted to the position optimization of the second accelerating cavity for the 3D ellipsoidal laser profile. Electron beam properties were compared for cylindrical and 3D ellipsoidal beams applying default and optimized booster positions. Beam tolerance studies revealed much better injector performance for the 3D ellipsoidal laser profile case with the optimized booster position. The outcome of such investigations is presented and discussed in this contribution.

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THPRO045

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

gun, electron, linac, simulation

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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THPRO046

100 MHz RF System as an Alternative for the Iranian Light Source Facility

cavity, HOM, storage-ring, operation

2968

S. Pirani, H. Ghasem, M. Moradi, Kh.S. Sarhadi
ILSF, Tehran, Iran

The Iranian Light Source Facility (ILSF) RF system was conceptually designed based on ILSF requirements for a 3GeV storage ring and 400 mA beam current at 500 MHz RF frequency. The development of HOM damped cavity with simpler structure at 100MHz and advantages of reducing frequency as investigated at MAX Lab, provided an alternative of 100MHz RF system to be explored for ILSF. RF frequency change and its effects on the beam and machine parameters as well as the availability and cost of RF system components have been studied for ILSF. The conceptual design of a 100MHz RF system and the comparison between 500 MHz and 100 MHz RF frequencies are presented in this report. This paper, furthermore, provides details about the 100MHz RF cavity designed by ILSF RF group based on MAX Lab cavity.

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THPRO047

Linac Design for the Proposed NSRRC THz/VUV FEL Facility

electron, linac, bunching, optics

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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THPRO048

Emittance and Bunch Length Measurement of the Electron Beams from the NSRRC Photocathode Gun

electron, gun, cavity, space-charge

2974

A.P. Lee, M.C. Chou, N.Y. Huang, J.-Y. Hwang, W.K. Lau, C.C. Liang
NSRRC, Hsinchu, Taiwan
P. Chiu, P. Wang
NTHU, Hsinchu, Taiwan
Y. Hao
BNL, Upton, Long Island, New York, USA

A high brightness photo-injector is under development for single pass FEL research at NSRRC. The gun test facility (GTF) equipped with a photocathode rf gun a compensation solenoid, a S-band high power pulse klystron as well as a UV driver laser has been constructed for testing the photocathode rf gun. The gun is fabricated in house and being tested at the GTF. Since the transverse emittance is a key property of the electron beam from the rf gun, multi-slit method is used to characterize the transverse emittance of the electron beam. Another key property of the electron beam is bunch length. An S-band three-cell deflecting cavity is designed to measure the bunch length. The setup and results of emittance measurement as well as the structure design of the deflecting cavity is reported in this contribution.

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THPRO051

Cavity Design for a S-Band Photoinjector RF Gun with 400 Hz Repetition Rate

cavity, gun, FEL, cathode

2983

J.W. McKenzie, L.S. Cowie, P. Goudket, B.L. Militsyn
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
V.V. Paramonov
RAS/INR, Moscow, Russia

As part of the design of CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility at Daresbury Laboratory, a high repetition rate S-band photoinjector RF gun is being developed. This gun will be able to operate at up to 400 Hz repetition rate in single bunch mode. We present the initial cavity design including its optimisation for the beam dynamics of CLARA. We also present the initial cooling design for the cavity which will enable the high repetition rates to be achieved.

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THPRO052

Beam Physics Commissioning of VELA at Daresbury Laboratory

gun, laser, diagnostics, quadrupole

2986

B.L. Militsyn, D. Angal-Kalinin, A.D. Brynes, F. Jackson, J.K. Jones, A. Kalinin, J.W. McKenzie, B.D. Muratori, T.C.Q. Noakes, D.J. Scott, E.W. Snedden, P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M.D. Roper
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

A user facility VELA (Versatile Electron Linear Accelerator) based on an RF photoinjector has been commissioned at Daresbury Laboratory in April 2013, providing beam to first users in September 2013. Machine study runs in 2013-2014 have concentrated on characterisation of main beam parameters like bunch charge, its momentum, beam emittance and dependence of these parameters on the launching RF phase. Major efforts have been also concentrated on investigation of the dark current from the gun and its dependence on the RF amplitude. Significant time has been dedicated to investigation of relative stability of LLRF and drive laser having significant impact on the overall machine stability. We present here the results of these studies.

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THPRO054

LLNL X-band Test Station Commissioning and X-ray Status

gun, laser, vacuum, alignment

2992

R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, M. Betts, S.E. Fisher, D.J. Gibson, F.V. Hartemann, S.S.Q. Wu
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
An X-band test station is being commissioned at LLNL to support inverse Compton-scattering x-ray and gamma-ray source development. The X-band test station has been built and this presentation will focus on its current status and the generation of first electron beam. Special focus will be placed on the high gradient conditioning of the T53 traveling wave accelerator and Mark 1 X-band standing wave RF gun. Design and installation of the inverse-Compton scattering interaction region, future upgrade paths and configuration for a variety of x-ray and gamma-ray applications will be discussed along with the status of theory and modeling efforts.

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THPRO058

Study of the “Particle-in-Cell” Induced Noise on High Intensity Beams

space-charge, simulation, synchrotron, resonance

3005

F. Kesting, G. Franchetti
GSI, Darmstadt, Germany
U. Ratzinger
IAP, Frankfurt am Main, Germany

Numerical noise in PIC codes produces artifacts which affects long term beam simulations needed for accelerator as the SIS100. A detailed study on the effect of numerical noise occurring in multi-particle tracking codes is presented. The influence of the granularity of particle distributions and the fineness of the meshes of Poisson solvers on the particle dynamics was studied. These results are used to discuss the effect of the PIC numerical noise in a long term space charge benchmarking study.

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THPRO066

Correction of the Higher Order Dispersion for Improving Momentum Acceptance

optics, storage-ring, electron, betatron

3029

M. Takao, K.K. Kaneki, Y. Shimosaki, K. Soutome
JASRI/SPring-8, Hyogo-ken, Japan

May 2013 we lowered the emittance of the SPring-8 storage ring from 3.5 nm¥cdotrad to 2.4 nm¥cdotrad to enhance the brilliance. At the optics change the momentum acceptance shrunk from 3.2 ¥% to 2.4 ¥%. Then, by carefully correcting the second order dispersion, we recovered the momentum acceptance up to 2.8 ¥%, which results in doubling the Touschek beam lifetime. Although the injection efficiency decreased by more than 10 ¥% by the dispersion correction, we restored it by means of suppressing the amplitude dependent tune shift. Here we describe these improvements of the nonlinear dynamics of the SPring-8 storage ring.

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THPRO071

Control of Calculations in the Beam Dynamics using Approximate Invariants

controls, quadrupole, experiment, database

3041

S.N. Andrianov
St. Petersburg State University, St. Petersburg, Russia
D. Zyuzin
FZJ, Jülich, Germany

One of the important problems in the theory of dynamical systems is to find corresponding (invariants). In this article we are discussing some problems of computing of invariant functions (invariants) for dynamical systems. These invariants can be used for describing of particle beams systems. The suggested method is constructive and based on the matrix formalism for Lie algebraic tools. We discuss two types of invariants: kinematic and dynamic. All calculations can be realized in symbolic forms, in particular, kinematic invariants are based on the theory of representations of Lie algebras (in particular, using the Casimir’s operators). For the case of nonlinear kinematic invariants we propose a recursive scheme, which can be implemented in symbolic forms using instruments of computer algebra (for example, such packages as Maple or Mathematica). The corresponding expressions for invariants can be used to control the correctness of computational experiments, first of all for long time beam dynamics.

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THPRO086

Flat-beam Generation and Compression at Fermilab's Advanced Superconducting Test Accelerator

quadrupole, simulation, laser, dipole

3086

J. Zhu, D. Mihalcea, P. Piot
Fermilab, Batavia, Illinois, USA
D. Mihalcea, P. Piot, C.R. Prokop
Northern Illinois University, DeKalb, Illinois, USA

An important asset of Fermilab’s Advanced Superconducting Test Accelerator (ASTA) is its ability to generate flat beams with high-transverse emittance ratios. In this paper, we present a practical design and simulation of flat beam generation and compression with various bunch charges up to 3.2 nC. Emittance growth within the round-to-flat beam transformer and the impact of low energy compression is discussed in detail. Finally, it is found that the compressed flat beam could provide exciting opportunities in the field of advanced acceleration techniques and accelerator-based light source.

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THPRO088

Optimization of the pp AGS Zgoubi Model in the Low Energy Range

resonance, simulation, acceleration, betatron

3089

Y. Dutheil, H. Huang, F. Méot, N. Tsoupas
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.
At low energy the AGS lattice is strongly deformed by the two strong helical snakes, required to preserve the polarization. In addition to the complex, highly non-linear field featured by the two snakes, multiple non-linear coupling resonance lines are crossed by the beam in this region. Hence, the use of realistic models for the Siberian snakes is critical for the simulation of the early part of the AGS acceleration cycle. The AGS Zgoubi model uses direct tracking through OPERA field maps of the two snakes. While many processes may be obnoxious to both beam and spin dynamics in this region, it is critical to use a realistic model of the AGS at low energy. This paper presents the current model used and some of the challenges recently faced. We will also compare experimental beam dynamics results to those predicted by the Zgoubi model.

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THPRO091

Strength of Horizontal Intrinsic Spin Resonances in the AGS

resonance, polarization, optics, proton

3098

Y. Dutheil, L. Ahrens, J.W. Glenn, H. Huang, F. Méot, T. Roser, V. Schoefer
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.
Crossing of horizontal intrinsic resonances is today the main source of polarization losses in the AGS, in its dual partial snakes configuration for polarized proton acceleration. Polarization losses were greatly reduced by the AGS tune jump system. However total polarization transmission through the AGS cycle is not yet achieved, still partially due to the horizontal intrinsic resonances. This paper will explore the effect of optical distortions and different horizontal tunes on the strength of horizontal intrinsic resonances. Various options will be presented and practicability will be addressed. Theoretical model and multiparticle trackings using the Zgoubi code will show the expected polarization gains of different scenarios.

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THPRO092

Stochastic Noise Effects in High Current PIC Simulation

space-charge, lattice, simulation, solenoid

3101

I. Hofmann, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O. Boine-Frankenheim, I. Hofmann
GSI, Darmstadt, Germany

The numerical noise inherent to particle-in-cell simulation of 3D high intensity bunched beams is studied with the TRACEWIN code and compared with the analytical model by Struckmeier (1994). The latter assumes the six-dimensional rms emittance or rms entropy growth can be related to Markov type stochastic processes due to temperature anisotropy and the artificial "collisions" caused by using macro-particles and calculating the space charge effect. Our entropy growth confirms the dependency on bunch temperature anisotropy as predicted by Struckmeier. However, we also find noise generation by the non-Liouvillean effect of the Poisson solver grid, which exists in periodic focusing systems even when local temperature anisotropy is absent - contrary to predictions by Struckmeier's model.

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THPRO094

Large Scale Particle Tracking and the Application in the Simulation of the RFQ Accelerator

rfq, software, simulation, space-charge

3107

L. Du, Q.Z. Xing
TUB, Beijing, People's Republic of China
Y.K. Batygin
LANL, Los Alamos, New Mexico, USA
Y. He, L. Yang
IMP, Lanzhou, People's Republic of China
J. Xu, R. Zhao
IS, Beijing, People's Republic of China

Large scale particle tracking is important for the design and optimization of the Radio-frequency Quadrupole (RFQ) accelerator. In this paper, we present RFQ simulation results of new parallel software named LOCUS3D, which is developed at Institute of Software, Chinese Academy of Sciences. It is based on Particle-In-Cell method and calculates three-dimensional space charge field by an efficient parallel fast Fourier transform method. A RFQ accelerator in Tsinghua University is simulated by tracking 100 million macro particles. This RFQ is designed to accelerate protons from 50 keV to 3 MeV, with peak beam current of 50 mA. As large number of particles been simulated, more accurate and detailed information have been obtained.

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THPRO096

Nonlinear Oscillations of a Sheet Electron Beam

electron, plasma, simulation, brightness

3113

H.Y. Barminova
MEPhI, Moscow, Russia

In collisionless approximation the nonlinear dynamics of continuous strong current intense electron beam is investigated. Nonlinear oscillations of the beam radius appear due to self-consistent nonlinear forces. To study these oscillations the model is used that automatically satisfy to Vlasov equation. The oscillations are described by means of Duffing equation. The equilibrium state is shown to exist. The solutions near the equilibrium state are analyzed. The asymptotic character of the solutions is found. Nonlinear beam transverse oscillations lead to filamentation and effective emittance growth. If particle energy dissipation is absent in the beam transportation channel the physical reason of the effective emittance growth is transfer of the part of the beam potential energy to kinetic energy of the particle transverse oscillations.

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THPRO097

Space-charge Neutralization of 750-keV H⁻ Beam at LANSCE

space-charge, beam-transport, simulation, ion

3116

Y.K. Batygin, C. Pillai, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

The injector part of Los Alamos Neutron Science Center (LANSCE) includes 750-keV H⁻ beam transport located upstream of the Drift Tube Linac. Space charge effects play an important role in the beam transport therein. A series of experiments were performed to determine the level of beam space charge neutralization, and time required for neutralization. Measurements performed at different places along the structure indicate significant variation of neutralized space charge beam dynamics along the beamline. Results of measurements were compared with numerical simulations using macroparticle method and envelope equations to determine values of the effective beam current after neutralization, and effective beam emittance, required for beam tuning.

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THPRO098

Realistic Modeling of 4-Rod RFQs with CST Studio

rfq, simulation, quadrupole, cavity

3119

S.S. Kurennoy, Y.K. Batygin, E.R. Olivas, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

RFQ accelerators are usually designed and modeled with standard codes based on electrostatic field approximations. There are recent examples when this approach fails to predict the RFQ performance accurately: for 4-rod RFQs 3D effects near the vane ends can noticeably influence the beam dynamics. The same applies to any RFQ where the quadrupole symmetry is broken, e.g., 4-vane RFQ with windows. We analyzed two 201.25-MHz 4-rod RFQs – one recently commissioned at FNAL and a new design for LANL – using 3D modeling with CST Studio. In both cases the manufacturer CAD RFQ model was imported into CST. The EM analysis with MicroWave Studio (MWS) was followed by beam dynamics modeling with Particle Studio (PS). For the LANL RFQ with duty factor up to 15%, a thermal-stress analysis with ANSYS was also performed. The simulation results for FNAL RFQ helped our Fermilab colleagues fix the low output beam energy. The LANL RFQ design was modified after CST simulations indicated insufficient tuning range and incorrect output energy; the modified version satisfies the design requirements. Our PS results were confirmed by multi-particle beam-dynamics codes that used the MWS-calculated RF fields.

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THPRO125

Synchronous Data Acquisition System for TPS and its Applications

data-acquisition, ground-motion, site, interface

3186

C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.H. Lee, C.Y. Liao, C.Y. Wu
NSRRC, Hsinchu, Taiwan

Orbit stability in 100 nm range is essential for a very small emittance synchrotron light source. However, all kinds of vibration source such as cultural noise and technical noise might deleterious the orbit stability. A synchronous data acquisition system is promising to study connection of orbit motion and various vibration related sources. In this report, we present a synchronous data acquisition system which integrates the measurement of beam position and vibration and then this system will deploy for the Taiwan Photon Source (TPS). To test the applicability of the system, systematic study orbit motion caused by vibration using this system was performed at Taiwan Light Source (TLS). Preliminary results will summary in this report.

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THPRO129

Online Modeling of the Rare Isotope Reaccelerator - ReA3

rfq, linac, 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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THPME001

Commissioning and Operation of the MedAustron Injector: Results and Future Outlook

ion, rfq, ion-source, DTL

3202

L.C. Penescu, M. Kronberger, T. Kulenkampff, F. Osmić, P. Urschütz
EBG MedAustron, Wr. Neustadt, Austria
W. Pirkl
CERN, Geneva, Switzerland

The MedAustron facility is a synchrotron-driven hadron therapy and research center presently under construction in Wiener Neustadt, Austria. In its final outline, the facility will provide H⁺ beams with kinetic energies ≤250MeV and C6+ beams of ≤400MeV/u for clinical applications, and for non-clinical applications H⁺ of up to 800MeV. First patient treatment is foreseen for the end of 2015. The (H3)+ and C4+ beams are generated at 8keV/u in continuous mode by three ECR ion sources and transported to the RFQ for acceleration to 400keV/u. An inter-tank section matches the beam to the entrance of an IH-mode DTL that accelerates the particles to 7MeV/u before they are stripped to, respectively, H⁺ and C6+, debunched and transported to the injection plane of the synchrotron. At a later stage of the project, beams of other species can be generated with similar optics. This contribution presents the results of the injector commissioning and operation. A comparison with the baseline optics and with the design error studies is given. In addition, an overview on the operational experience is given, with emphasis on the system reliability, stability and reproducibility.

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THPME003

A Precise Determination of the Core-halo Limit

linac, 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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THPME005

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

linac, 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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THPME006

Straight Injection of an intense Uranium Beam into the GSI High Current RFQ

ion, rfq, ion-source, quadrupole

3217

H. Vormann, A. Adonin, W.A. Barth, L.A. Dahl, P. Gerhard, L. Groening, R. Hollinger, M.T. Maier, S. Mickat, A. Orzhekhovskaya, C. Xiao, S.G. Yaramyshev
GSI, Darmstadt, Germany

A dedicated high current uranium ion source and LEBT will be built at the GSI High Current Injector (HSI), to fulfil the intensity requirements for FAIR (Facility for Antiproton and Ion Research at Darmstadt). This new injection line will be integrated into the existing complex which already comprises two branches. The new LEBT is designed as a straight injection line without dipole magnet, i.e. without dispersive charge state separation. All uranium charge states, coming from the ion source, are transported to the heavy ion high current GSI-HSI-RFQ. Only the design charge state U⁴⁺ is accelerated to the final RFQ energy. The new LEBT design is based on beam emittance and current measurements behind the existing ion source. Beam dynamics simulations have been performed with the codes TRACE-3D (envelopes), DYNAMION, BEAMPATH and TRACK (multiparticle). The recent layout of the LEBT, as well as the results of beam dynamics studies are presented.

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THPME007

A Virtual Charge State Separator as an Advanced Tool Coupling Measurements and Simulations

ion, simulation, quadrupole, ion-source

3220

S.G. Yaramyshev, A. Adonin, W.A. Barth, L.A. Dahl, P. Gerhard, L. Groening, R. Hollinger, M.T. Maier, S. Mickat, A. Orzhekhovskaya, H. Vormann
GSI, Darmstadt, Germany

A new Low Energy Beam Transport (LEBT) for multi-charge uranium beam will be built at GSI High Current Injector. All uranium charge states coming from the new ion source will be injected into GSI heavy ion high current HSI-RFQ, but only design ions U⁴⁺ will be accelerated to the final RFQ energy. A detailed knowledge about injected beam- current and -emittance for pure design U⁴⁺ ions is necessary for a proper beam line design commissioning and operation, while the measurements are possible only for a full beam including all charge states. Detailed measurements of beam current and emittance are performed behind the first quadrupole triplet at the beam line. A dedicated algorithm, based on combination of measurements and results of an advanced beam dynamics simulations, provides for an extraction of beam- current and -emittance for only U⁴⁺ component of a beam. The obtained results and final beam dynamics design for the new straight beam line are presented.

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THPME008

New Reference Design of the European ADS RFQ Accelerator for MYRRHA

rfq, simulation, bunching, operation

3223

C. Zhang
GSI, Darmstadt, Germany
H. Podlech
IAP, Frankfurt am Main, Germany

For demonstrating the technical feasibility of nuclear waste transmutation in an Accelerator Driven System (ADS), the MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) proton driver is under intensive studies. Good performance of the 2 – 4 mA, 1.5MeV RFQ (Radio-Frequency Quadrupole), the start of the accelerator chain, is essential to the reliability of the whole facility, so it must be very well designed. On the basis of the first reference design, further improvements with respect to electrode aperture, emittance growths and output distributions have been performed. The simulation results of the new reference design are presented in this paper.

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THPME014

Beam Dynamics in the LEBT for FRANZ

rfq, solenoid, injection, simulation

3241

P.P. Schneider, H. Dinter, M. Droba, O. Meusel, D. Noll, T. Nowottnick, O. Payir, H. Podlech, A. Schempp, C. Wiesner
IAP, Frankfurt am Main, Germany

The two Low Energy Beam Transport (LEBT) sections of the accelerator-driven neutron source FRANZ* consist of four solenoids. The first section with two solenoids will match the 120 keV proton beam into a chopper system**. Downstream from the chopper system a second section with two more solenoids will match the beam into the acceptance of the following RFQ. The accelerator will be operated using either a 2 mA dc beam or a pulsed beam with intensities from 50 mA to 200 mA at 250 kHz repetition rate. The high intensity of these ion beams requires the consideration of space-charge effects. Particle simulations with varying parameter sets have been performed in order to determine the settings providing best transmission and beam quality. Loss profiles along the transport channel were computed to identify hotspots. Simulation results for best transmission at lowest emittance growth will be presented.
* O. Meusel et al., Proc. of LINAC12, Tel-Aviv, Israel, MO3A03
** C. Wiesner et al., Proc. of IPAC2012, New Orleans, LA., USA, THPPP074

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THPME019

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

rfq, linac, proton, 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, cavity, focusing, linac

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

linac, 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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THPME041

ESS DTL Status: Redesign and Optimizations

DTL, linac, 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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THPME044

Statistical Error Studies in the ESS Linac

rfq, linac, 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, linac, rfq, lattice

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, linac, beam-losses, 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

linac, ion, rfq, ion-source

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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THPME057

Calculations of Halo in TraceWin Code

diagnostics, linac, 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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THPME073

Performance of the Low Energy Beam Transport at the RAL Front End Test Stand

solenoid, rfq, ion, ion-source

3406

J.J. Back
University of Warwick, Coventry, United Kingdom
D.C. Faircloth, A.P. Letchford
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration (0-3 MeV) and beam chopping required for high power proton accelerators, including proton drivers for pulsed neutron spallation sources and neutrino factories. A Low Energy Beam Transport (LEBT), consisting of three solenoids and four drift sections, is used to transport the H⁻ beam from the ion source to the Radio Frequency Quadrupole (RFQ). We present the current performance of the LEBT with regards to beam alignment, transmission and focusing into the acceptance of the RFQ.

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THPME081

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

storage-ring, synchrotron, linac, 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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THPME082

Sirius Diagnostic Beamlines

dipole, radiation, diagnostics, synchrotron

3427

N. Milas, L. Liu, A.R.D. Rodrigues
LNLS, Campinas, Brazil

Sirius is a 3 GeV synchrotron light source that is being built by the Brazilian Synchrotron Light Laboratory (LNLS). It will be part of a novel class of light sources with emittances in the sub-nm level. Both horizontal and vertical beam sizes at the dipoles will be of the order of or below 10μm, creating difficulties for measuring them using conventional techniques. This paper proposes a series of beamlines using different techniques that, combined, will be able not only to resolve beam sizes, but also measure energy spread and local transverse coupling in the storage ring.

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THPME119

Transverse emittance measurement at REGAE

electron, target, diagnostics, simulation

3515

S. Bayesteh
Uni HH, Hamburg, Germany
H. Delsim-Hashemi, K. Flöttmann
DESY, Hamburg, Germany

A new linac, named REGAE (Relativistic Electron Gun for Atomic Exploration) has been built at DESY and operates as an electron source for ultra-fast electron diffraction. An RF photocathode gun provides electron bunches of high coherence, sub-pC charge and energies of 2-5 MeV. In order to film time-resolved structural changes of excited specimens, bunch lengths of several femtoseconds need to be created. Taking into account these critical parameters, beam diagnostics at REGAE is very challenging. The existing diagnostics consists of energy, energy spread, beam profile, beam charge and emittance measurements. For transversal diagnostics, specific approaches have to be considered to overcome complications associated with the low charge and to carry out the beam diagnostics in single shot. In this paper, the contribution of the transversal diagnostics to the measurement of the transverse emittance is presented.

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THPME139

Emittance Measurement with Wire Scanners at CADS MEBT1

rfq, quadrupole, space-charge, linac

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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THPME140

New Beam Diagnostics and Related Study on HLS Photo-Injector and HLS II

cavity, quadrupole, diagnostics, electron

3578

Q. Luo, H.T. Li, P. Lu, B.G. Sun, K. Tang, J.J. Zheng, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by Natural Science Foundation of China 11005105, 11005106, 11205156 and 11375178.
A team in NSRL is now doing research about small model accelerators and carrying out series of related experiments on HLS photo-injector and HLS II storage ring. Cavity beam multi-parameter monitor system designed for the HLS photocathode RF electron gun consists of a beam position monitor, a beam quadrupole moment monitor and a beam density and bunch length monitor. TM0n0 modes of cavity can be used to work out beam density and bunch length simultaneously. Miniaturization of FEL facilities is now being studied based on results of experiments and theoretical work before. The team also participate in commissioning of HLS II, i.e. measured work points of the new storage ring and did some research on longitudinal bunch-by-bunch feedback system.

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THPME143

Measuring Energy Spread Using Beam Screen Monitor and Four Strip-Line Electrodes for Hls II Injector*

quadrupole, LabView, brilliance, EPICS

3587

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

In order to nondestructively measure the beam energy spread with a beam energy of 0.8GeV in the injector at the upgrade project of Hefei Light Source (HLS II) in real time, a beam energy spread monitor (BESM) using beam position monitor (BPM) with four stripline electrodes has been developed. And a screen monitor (SM) near the BESM is used to measure beam energy spread destructively. This paper introduces in brief the beam position measurement system and beam transverse profile measurement system. The relationship between the transverse size at the BESM and at the SM (Flag3) is discussed in detail in this report. The result shows that energy spread measuring result of BESM and SM is 0.19% and 0.18% respectively. So we can draw a conclusion that the BESM is capable of nondestructively measuring the beam energy spread.

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THPME148

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

linac, 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

linac, ion, 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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THPME163

Beam Size and Emittance Reconstruction in the RMTL of Future Linear Colliders

diagnostics, target, optics, coupling

3647

A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain

Funding: Work supported by FPA2010-21456-C02-01
Precise and fast beam size measurement and emittance reconstruction in the different subsystems and transfer lines of the Future Linear Colliders (ILC and CLIC) will be essential for beam tuning in order to achieve the required luminosity. In this paper we investigate the feasibility of using a multi-Optical Transition Radiation (m-OTR) system for fast transverse beam size measurement, emittance reconstruction and coupling correction in the Ring to Main Linac (RTML) of the FLCs. Diagnostic sections of the RTML have been matched to the optimum optical conditions for emittance reconstruction. The necessary requirements for the OTR monitors to be placed in the RTML are discussed.

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THPME169

Status of the New Beam Size Monitor at SLS

alignment, optics, laser, radiation

3662

J. Breunlin, Å. Andersson
MAX-lab, Lund, Sweden
N. Milas
LNLS, Campinas, Brazil
M. Rohrer, A. Saá Hernández, V. Schlott, A. Streun
PSI, Villigen PSI, Switzerland

The Swiss Light Source (SLS) campaign on vertical emittance minimization and measurement required a beam size monitor with the ability to verify a sub-pmrad vertical emittance. This corresponds to a beam height of less than 4 μm. Within the TIARA Work Package ‘SLS Vertical Emittance Tuning’ a new beam size monitor was designed and built. The monitor is based on the imaging of the pi-polarized synchrotron radiation (SR) in the visible and UV spectral ranges. Besides imaging the monitor provides interferometric methods using vertically or horizontally polarized SR. With these complementary methods the consistency of beam size measurements is verified. An intermediate configuration of the monitor beamline using a lens as the focusing element has been commissioned in 2013. With this setup a vertical beam size of 4.8±0.5 μm, corresponding to a vertical emittance of 1.7±0.4 pmrad has been measured. During 2014 the monitor was commissioned in its final configuration with a toroidal mirror. The use of reflective optics allows wider bandwidth imaging and thus higher intensity. We report on challenges during commissioning and present first images of SR taken with the toroidal mirror.

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THPME173

Beam-based Measurements of the CPS Wire Scanner Precision and Accuracy

synchrotron, simulation, optics, proton

3674

G. Sterbini, B. Dehning, S.S. Gilardoni, A. Guerrero
CERN, Geneva, Switzerland

During 2013 run a systematic campaign of beam-based measurement on the CERN Proton Synchrotron wire scanners has been performed. In this work we report the conditions of the measurements, we describe the results and their interpretation. The observations are compatible with an emittance relative precision and accuracy respectively better than 2 % and 5 % in the vertical plane for nTOF beams. The present limitations of the system are discussed and possible solutions are presented.

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THPME179

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

linac, 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, linac, 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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THPME191

Simulation Results of the FETS Laserwire Emittance Scanner

laser, ion, detector, simulation

3729

K.O. Kruchinin, A. Bosco, S.M. Gibson, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
D.C. Faircloth
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The Front End Test Stand (FETS) at Rutherford Appleton Laboratory (RAL) has been developed to demonstrate a high current (60 mA) H⁻ beam with the energy of 3 MeV that will be required for future proton drivers. At such high power beam machine a non-invasive diagnostics is required. To measure the emittance of the ion beam a laserwire scanner is being developed. A high power laser will scan across the H⁻ ion beam. The H⁻ particles will be neutralized via a photo-detachment process producing a stream of fast neutral hydrogen atoms bearing information about the phase space distribution of the initial H⁻ beam. To design an effective detection system and optimize its parameters a simulation of the processes at the interaction point is required. We present recent simulation results of theц FETS laserwire system. Simulations were performed using measured data of the laser propagation and ion beam distribution, obtained with General Particle Tracer code.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPME191

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THPRI001

Design of a High Luminosity Tau/Charm Factory

luminosity, sextupole, injection, dipole

3757

M.E. Biagini, R. Boni, M. Boscolo, A. Chiarucci, R. Cimino, A. Clozza, E. Di Pasquale, A. Drago, S. Guiducci, C. Ligi, G. Mazzitelli, R. Ricci, C. Sanelli, M. Serio, A. Stella, S. Tomassini
INFN/LNF, Frascati (Roma), Italy
S. Bini, F. Cioeta, D. Cittadino, M. D'Agostino, M. Del Franco, A. Delle Piane, G. Frascadore, R. Gargana, S. Gazzana, S. Incremona, A. Michelotti, L. Sabbatini
Consorzio Laboratorio Nicola Cabibbo, Frascati, Italy
N. Carmignani, S.M. Liuzzo, P. Raimondi
ESRF, Grenoble, France
R. Petronzio
Università di Roma II Tor Vergata, Roma, Italy
M.T.F. Pivi
IMS Nanofabrication AG, Vienna, Austria
G. Schillaci, M. Sedita
INFN/LNS, Catania, Italy

The design of a high luminosity Tau/Charm Factory has been accomplished by the INFN-LNF Laboratory in Frascati in collaboration with the Consortium Nicola Cabibbo Laboratory. The target luminosity is 10³⁵ cm^-2 ses⁻¹ at 4.6 GeV in the center of mass. This design is a natural evolution of the SuperB B-Factory, that was aimed to be built in the Rome Tor Vergata University campus as an Italian Flagship Project. The Tau/Charm design keeps all the features that made SuperB a state-of-the art accelerator, such as the “large Piwinski angle and crab waist sextupoles” collision scheme, the super squeezed beams, and the polarized electron beam. As a plus, it will be possible to collect data at high luminosity in a large energy range (2 to 4.6 GeV c. m.), with a peak luminosity target of 10³⁴ cm^-2 ses⁻¹ at 2 GeV. The possibility to extend the Linac for a SASE-FEL facility is also taken into account. A Conceptual Design Report* was published in September 2013. In this paper the design principles and the project features are reviewed.
* Tau/Charm Factory Accelerator Report, INFN Report INFN-13-13/LNF, September 2013, arXiv:1310.6944 [physics.acc-ph]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI001

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THPRI030

Progress Towards Completion of the MICE Demonstration of Muon Ionization Cooling

cavity, solenoid, coupling, lattice

3831

D.M. Kaplan, P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA
A.J. Dobbs
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
P. Snopok
Fermilab, Batavia, Illinois, USA

Funding: DOE, NSF, STFC, INFN, CHIPP and several others
The Muon Ionization Cooling Experiment (MICE) at the Rutherford Appleton Laboratory aims to demonstrate ~10% ionization cooling of a muon beam, by its interaction with low-Z absorber materials followed by restoration of longitudinal momentum in RF linacs. MICE Step V will provide the flexibility for a thorough exploration and characterization of the performance of ionization cooling. Step V will include four RF cavities to provide 8 MV/m gradient in a strong magnetic field. This entails an RF drive system to deliver 2 MW, 1 ms pulses of 201 MHz frequency at 1 Hz repetition rate, the distribution network to deliver 1 MW to each cavity with correct RF phasing, diagnostics to determine the gradient and the muon transit phase, and development of the large diameter magnets required in order to keep the muons focused through the linacs. Progress towards the completion of Step V is described.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI030

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THPRI033

Design of New Buncher Cavity for Relativistic Electron Gun for Atomic Exploration – REGAE

cavity, simulation, electron, operation

3840

M. Fakhari, H. Delsim-Hashemi, K. Flöttmann, M. Hüning, S. Pfeiffer, H. Schlarb
DESY, Hamburg, Germany
J. Roßbach
Uni HH, Hamburg, Germany

The Relativistic Electron Gun for Atomic Exploration, REGAE, is a small electron accelerator build and operated at DESY. Its main application is to provide high quality electron bunches for time resolved diffraction experiments. The RF system of REGAE contains different parts such as low level RF, preamplifier, modulator, phase shifter, and cavities. A photocathode gun cavity to produce the electrons and a buncher cavity to compress the electron bunches in the following drift tube. Since the difference between the operating mode of the existing buncher and its adjacent mode is too small, the input power excites the other modes in addition to the operating mode which affects the beam parameters. A new buncher cavity is designed in order to improve the mode separation. Furthermore the whole cavity is modeled by a circuit which can be useful especially during the tuning process. Beam dynamics simulations have been performed in order to compare the new designed cavity with the old one which declare that the effects of the adjacent modes on the beam parameters are decreased.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI033

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THPRI101

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

wakefield, cavity, linac, 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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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-THPRI101

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