IPAC2017 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOOCB1	Time-Resolved Energy Spread Studies at the ANKA Storage Ring	storage-ring, timing, detector, synchrotron	53
	B. Kehrer, E. Blomley, M. Brosi, E. Bründermann, A.-S. Müller, M.J. Nasse, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, N.J. Smale, J.L. Steinmann KIT, Karlsruhe, Germany N. Hiller PSI, Villigen PSI, Switzerland P. Schütze DESY, Hamburg, Germany
	Funding: This work has been supported by the Initiative and Networking Fund the Helmholtz Association under contract number VH-NG-320 and the BMBF under contract numbers 05K13VKA and 05K16VKA. Recently, a new setup for measuring the beam energy spread has been commissioned at the ANKA storage ring at the Karlsruhe Institute of Technology. This setup is based on a fast-gated intensified camera and detects the horizontal profiles of individual bunches in a multi-bunch environment on a single-turn base. As the radiation source point is located in a dispersive section of the storage ring, this allows time-resolved studies of the energy spread. These studies are of particular interest in the framework of short-bunch beam dynamics and the characterization of instabilities. The system is fully synchronized to other beam diagnostics devices allocated in various places along the storage ring, such as the single-shot electro-optical spectral decoding setup or the turn-by-turn terahertz detection systems. Here we discuss the results of the synchronous measurements with the various systems with special emphasis on the energy spread studies.
	Slides MOOCB1 [6.514 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOOCB1
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MOPAB004	Improved Protection of the Warm Magnets of the LHC Betatron Cleaning Insertion	shielding, operation, luminosity, collimation	72
	C. Bahamonde Castro, F. Cerutti, P. Fessia, A. Lechner, A. Mereghetti, D. Mirarchi, S. Redaelli, E. Skordis CERN, Geneva, Switzerland E. Skordis The University of Liverpool, Liverpool, United Kingdom
	After the High Luminosity (HL) upgrade in 2024-2026, the LHC is anticipated to increase its integrated luminosity by a factor of 10 beyond its original design value of 300 fb-1. In preparation for this, several improvements to the equipment will already be implemented during the next Long Shutdown (LS2) starting in 2019. In the betatron cleaning insertion, the debris leaking out of several collimators will deposit energy in the downstream warm magnets, causing long-term radiation damage. A new layout has been proposed in which the most exposed magnet of each assembly is removed, reducing the assembly from 6 to 5 magnet units and gaining 2 spare magnets. New absorbers are therefore required to enhance the shielding of the remaining magnet string. In this paper, we present an evaluation of the dose to the warm magnets for post-LS2 operation, and we quantify the achievable reduction of the long-term radiation damage for different absorber configurations. A solution for an improved magnet protection that fulfills the HL-LHC requirements is proposed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB004
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MOPAB021	Performance of OTR and Scintillator View Screens for the ARIEL Electron Linac	target, linac, optics, scattering	117
	D.W. Storey, J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger Victoria University, Victoria, B.C., Canada P.S. Birney, P.E. Dirksen, S.R. Koscielniak, M. Lenckowski TRIUMF, Vancouver, Canada
	The ARIEL electron linac is a 0.3 MW CW accelerator, extensible to 0.5 MW, being installed at TRIUMF for radioactive beam production. To date, 17 view screen monitors have been installed along the beamline and have proven to be essential tools in the commissioning of e-linac systems. These are populated by two types of beam targets: P46 scintillator screens which provide diagnostics for low duty factor operation, while at locations with beam energies at and above 10 MeV, OTR foils using either Pyrolytic Graphite or Niobium foils are included to provide coverage up to 100's of μA average beam current. The design of the view screen is described including the image acquisition system and beam target selection. The performance thus far of the OTR foils under low duty factor commissioning is presented including quantification of the OTR emission distribution, thermal studies, and transmission of the beam through the linac after intercepting a foil.
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MOPAB024	Proposal to Observe Half-Bare Electrons on a 40-MeV LINAC	electron, experiment, laser, linac	126
	N. Delerue, S. Jenzer, V. Khodnevych, A. Migayron LAL, Orsay, France N.F. Shul'ga NSC/KIPT, Kharkov, Ukraine S. Trofymenko KhNU, Kharkov, Ukraine
	Funding: CNRS/IN2P3 and Joint Laboratory France-Ukraine IDEATE In different processes of relativistic electron interaction with substance and external fields, the electron loses part of its Coulomb field and becomes half-bare. Such state of electron significantly modifies the characteristics of its electromagnetic radiation during further interaction of the particle with substance. We propose to study the influence of the half-bare state of electron upon its transition radiation (TR). The existence of such influence for the case of electron undressing at its scattering was theoretically predicted. We intend to obtain the electrons in half-bare state in the result of their crossing of a conducting screen such as a TR screen. We propose to investigate the influence of the half-bare state of electron in this process upon TR generated by such electron on a downstream TR screen situated on some distance from the upstream screen which undresses the particle. Calculations are presented for the case of a 45-MeV linac and the distance between the screens in the region between 100 mm and 300 mm. The proposed experiment is expected to reveal new features of TR signal in such process comparing to previous measurements. N.F. Shul'ga, S.V. Trofymenko, V.V. Syshchenko, JETP Lett. 93 (2011) 1. Y. Shibata, K. Ishi, T. Tokahashi et al., Phys. Rev. E 49 (1994) 785.
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MOPAB025	Measurement of the Polarisation of Coherent Smith-Purcell Radiation in the SOLEIL Linac	polarization, detector, linac, experiment	129
	N. Delerue, S. Jenzer, V. Khodnevych LAL, Orsay, France N. Hubert, M. Labat, J.-P. Pollina, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	Funding: CNRS/IN2P3, Université Paris-Sud and ANR (contract ANR-12-JS05-0003-01) SPESO is an experiment installed in the Linac of Synchrotron SOLEIL to study the Coherent Smith-Purcell radiation produced when a grating is approached from the beam. The detectors used to measure this radiation are mounted on 3-translation axis and 2 rotation axis. This allows measurements of the radiation emission map around the grating. In addition a polarizer has been added in 2016 allowing to study the two polarization components of the radiation in this map. Preliminary results of this mapping will be presented.
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MOPAB026	Study of a Smith-Purcell Radiation-Based Longitudinal Profile Monitor at the CLIO Free Electron Laser	electron, laser, free-electron-laser, detector	132
	V. Khodnevych, N. Delerue, S. Jenzer, H. Roesch LAL, Orsay, France J.P. Berthet, F. Glotin, J.-M. Ortega, R. Prazeres LCP/CLIO, Orsay, Cedex, France N. Jestin CLIO/ELISE/LCP, Orsay, France
	Funding: CNRS and ANR (contract ANR-12-JS05-0003-01) We report on measurements of Coherent Smith-Purcell radiation at the CLIO Free Electron Laser. Smith-Purcell radiation is emitted when a grating is brought close from a bunch of relativistic particles. When the bunch is sufficiently short coherent radiation is emitted. This coherent radiation encodes the longitudinal form factor of the bunch and can therefore be used as a longitudinal profile monitor. With its short pulses and high charge the 45 MeV Linac of CLIO is a good location to test advanced longitudinal profile diag- nostics. The results will be compared with measurements using the RF dephasing. induced energy dispersion.
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MOPAB032	Status of a Double Slit Interferometer for Transverse Beam Size Measurements at BESSY II	diagnostics, storage-ring, synchrotron, operation	149
	M. Koopmans, P. Goslawski, J.G. Hwang, M. Ries, M. Ruprecht, A. Schälicke HZB, Berlin, Germany
	Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association The upgrade of the BESSY II storage ring to BESSY VSR* demands additional beam diagnostics for machine commissioning and development. Especially bunch resolved measurements are needed. Currently, transverse beam size measurements are done with X-ray pinhole monitor systems, which cannot provide bunch resolved information. Alternative methods to measure the transverse beam size using synchrotron radiation in the visible spectrum are interferometric techniques, which could also be upgraded to bunch resolved systems. For that purpose a double slit interferometer has been constructed. Commissioning of the system has started and experimental results are discussed and compared with the existing pinhole system. * A. Jankowiak et al., eds., ''BESSY VSR - Technical Design Study'', Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany, June 2015.
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MOPAB042	Two-Dimensional Synchrotron Radiation Interferometry at PETRA III	synchrotron, emittance, synchrotron-radiation, operation	177
	A.I. Novokshonov, A. Potylitsyn TPU, Tomsk, Russia G. Kube DESY, Hamburg, Germany
	Synchrotron radiation interferometry is widely used at modern 3rd generation light sources in order to measure transverse electron beam sizes. The technique is based on probing of the spatial coherency of synchrotron radiation in the visible spectral region. The light source PETRA III at DESY (Hamburg, Germany) is using this type of interferometer since several years in order to resolve vertical emittances of about 10 pm.rad. In order to overcome some inherent disadvantages in this setup, a new optical diagnostics beamline was recently commissioned with a two-dimensional interferometer, thus allowing to measure beam sizes in both transverse planes simultaneously. This contribution summarizes the status of the interferometer with first operational experience and describes systematical studies concerning the stability and possibilities to increase the sensitivity on small beam sizes using an intensity imbalance technique.
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MOPAB055	Towards Near-Field Electro-Optical Bunch Profile Monitoring in a Multi-Bunch Environment	electron, wakefield, laser, storage-ring	227
	P. Schönfeldt, E. Blomley, E. Bründermann, M. Caselle, S. Funkner, N. Hiller, B. Kehrer, A.-S. Müller, M.J. Nasse, G. Niehues, L. Rota, M. Schedler, M. Schuh, M. Weber KIT, Karlsruhe, Germany
	Funding: This work is funded by the BMBF contract numbers: 05K13VKA and 05K16VKA. For electron accelerators, electro-optical methods in the near-field have been shown to be a powerful tool to detect longitudinal bunch profiles. In 2013, we demonstrated for the first time, electro-optical bunch profile measurements in a storage ring at the accelerator test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT). To study possible bunch-bunch interactions and its effects on the longitudinal dynamics, these measurements need to be performed in a multi-bunch environment. Up to now, due to long-ranging wake-fields the electro-optical monitoring was limited to single-bunch operation. Here, we present our new in-vacuum setup to overcome this limitation. First measurements show reduced wake-fields in particular around 2 ns, where the subsequent bunch can occur in a multi-bunch environment at ANKA.
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MOPAB056	4-Channel Single Shot and Turn-by-Turn Spectral Measurements of Bursting CSR	detector, synchrotron, simulation, storage-ring	231
	J.L. Steinmann, E. Blomley, M. Brosi, E. Bründermann, M. Caselle, B. Kehrer, A.-S. Müller, L. Rota, M. Schuh, P. Schönfeldt, M. Siegel, M. Weber KIT, Karlsruhe, Germany
	The test facility and synchrotron radiation source ANKA at the Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany, can be operated in a short-bunch mode. Above a threshold current, the high charge density leads to microwave instabilities and the formation of sub-structures. These time-varying sub-structures on bunches of picosecond duration lead to the observation of bursting coherent synchrotron radiation (CSR) in the terahertz (THz) frequency range. The spectral information in this range contains valuable information about the bunch length, shape and sub-structures. We present recent measurements of a spectrometer setup that consists of 4 ultra-fast THz detectors, sensitive in different frequency bands, combined with the KAPTURE readout system developed at KIT for studies requiring high data throughput. This setup allows to record continuously the spectral information on a bunch-by-bunch and turn-by-turn basis. This contribution describes the potential of time-resolved spectral measurements of the short-bunch beam dynamics.
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MOPAB060	Thermal Issues for the Optical Transition Radiation Screen for the ELI-NP Compton Gamma Source	electron, target, simulation, laser	246
	F. Cioeta, D. Alesini, A. Falone, V.L. Lollo, L. Pellegrino, A. Variola INFN/LNF, Frascati (Roma), Italy M. Ciambrella University of Rome La Sapienza, Rome, Italy D. Cortis, M. Marongiu, V. Pettinacci INFN-Roma, Roma, Italy A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy
	A high brightness electron Linac is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with the laser beam in two interaction points. Electron beam spot size is measured with optical transition radiation (OTR) profile monitors. In order to measure the beam properties, the OTR screens must sustain the thermal and mechanical stress due to the energy deposited by the bunches. This paper is an ANSYS study of the issues due to the high energy transferred to the OTR screens. Thermal multicycle analysis will be shown; each analysis will be followed by a structural analysis in order to investigate the performance of the material. The multiphysics analysis will be extended to the mechanical contact areas with the target frame in order to evaluate the order of magnitude of the phenomena in those regions.
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MOPAB066	Development and Performance Test of the BPM System for the SPring-8 Upgrade	simulation, storage-ring, electron, photon	265
	H. Maesaka RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan H. Dewa, T. Fujita, M. Masaki JASRI, Hyogo, Japan S. Takano Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
	We are developing a stable and precise BPM system for the low-emittance upgrade of SPring-8. One of the essential requirements for the BPM is the long term stabilization of the photon beam by regulating the electron beam orbit. Both the single-pass resolution of 100 um rms for an injected beam charge of 100 pC and an accuracy of 100 um rms are also crucial for beam commissioning. Drift sources of the present BPM system have been investigated extensively, such as humidity-dependent drifts coming from the radiation damage of coaxial cables, and the results are fed back to the design of the new BPM system. We have optimized the design of the button BPM electrodes to reconcile reduction of trapped-mode heating and maximization of the signal intensity. Stringent machining tolerance is imposed on a BPM head to align the BPM electric center accurately. A few kinds of the BPM head prototypes were produced and the machining accuracy, RF characteristics etc. were confirmed to be sufficient. We have installed one of the prototypes in the present storage ring to test the performance of the new BPM system under development, and have been obtaining successful results satisfying the requirements.
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MOPAB073	Measurement of Electron-Bunch Length Using Coherent Radiation in Infrared Free-Electron Laser Facilities	electron, FEL, detector, laser	288
	N. Sei, H. Ogawa AIST, Tsukuba, Ibaraki, Japan K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, T. Tanaka LEBRA, Funabashi, Japan H. Ohgaki, H. Zen Kyoto University, Kyoto, Japan
	Funding: This study was financially supported by JSPS KAKENHI Grant Number JP16H03912. We have studied techniques evaluating bunch length of micropulses in an electron beam. The bunch length of the electron beam is an important parameter for free-electron laser (FEL) facilities with linear accelerators. In order to obtain high FEL gain at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University and at Kyoto University Free Electron Laser (KU-FEL), the electron-bunch length is compressed to less than 1 ps in their undulator sections. Using the compressed electron beams, intense terahertz lights were generated by coherent radiation. The power of the coherent radiation was more than 50 micro-joule per electron-beam macropulse. We can extract the information of the bunch length of the electron-beam micropulse from the intense coherent radiation by using narrow-band diode detectors. In this presentation, experimental results of the measurements of the root-mean-square electron-bunch length using the coherent radiation at LEBRA* and KU-FEL** will be reported. : N. Sei et al., J. Opt. Soc. Am. B, 31, 2150 (2014). *: N. Sei et al., Nucl. Instrum. Methods Phys. Res., Sect. A, 832, 208 (2016).
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MOPAB075	Measurement of Electron Bunch Length via a Tunable-Gap Undulator	electron, undulator, laser, acceleration	295
	X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan TUB, Beijing, People's Republic of China Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	A THz undulator with widely tunable gap is constructed and installed at Tsinghua University beamline, which is applied for narrow-band THz radiation and measurements of electron bunch longitudinal structure. This is a planar electromagnetic device with 8 regular periods, each 10 cm long. The field range B=0.15- 0.99 T peak field on axis while changing the gap from 75mm to 23mm. In the experiments, we scanned the undulator gap to measure the radiation intensity at different resonant frequency, thus we can get the bunch length even form factor of the bunch. The demonstrated experimental results show that the bunch of 220pC compressed by chicane in Tsinghua beamline is about 120fs (rms), which agree well with the simulations. The resolution of bunch length measurement with this method can be attoseconds by optimized undulator. Furthermore, the form factor of electron bunch train can also be measured.
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MOPAB076	2D Beam Profile Monitors at CPHS of Tsinghua University	proton, target, ion, electronics	298
	W. Wang, X. Guan, W.-H. Huang, Y. Lei, X.W. Wang, Q.Z. Xing, S.X. Zheng TUB, Beijing, People's Republic of China L. Du CEA/IRFU, Gif-sur-Yvette, France M.T. Qiu, Z.M. Wang State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China
	Beam profile is a key parameter for high current proton linac. Compact Pulsed Hadron Source(CPHS) has two type of detectors to monitor beam 2D beam profile: scintillator screen and rotatable multi-wire scanner. A retractable chromium-doped alumina (Chromox) screen is used as scintillator, emitted lights when impacted by proton are captured by a 12 bit CCD camera. Nineteen carbon fibre wires with a diameter of 30 'm, 3 mm separated from each other, are used to measure beam 1D distribution. Projection can be measured at different direction by rotating the multi-wire scanner about beam direction. 2D beam distribution is reconstructed from multiple projections with the help of CT. Different CT algorithms, Algebra Reconstruct Technique (ART) and Maximum Entropy algorithm (MENT), are applied to achieve accurate or quick reconstruction. The preliminary experimental results show the two profile monitors working consistently with each other.
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MOPAB084	Online Measurement of Electrode Gains for Stripline Beam Position Monitor in the HLS II Storage Ring	storage-ring, quadrupole, site, operation	316
	F.F. Wu, L. Lin, X.Y. Liu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang, J.H. Wei, Y.L. Yang, T.Y. Zhou, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by the National Key Research and Development Program of China(No. 2016YFA0402000) and the National Science Foundation of China (11575181, 11605202) Three axially symmetric stripline beam position monitors were installed in the HLS II storage ring and each stripline BPM was machined with button BPM together. Due to mechanical errors of stripline BPM, differences in electrode gains will lead to measurement error for beam position and mutual coupling between beam horizontal position and vertical position. So it is very important to calibrate electrode gains for axially symmetric BPM. A method was proposed to calibrate electrode gains of this kind of BPM. This method is suitable for all axially symmetric BPMs, whether stripline BPM or button BPM. The online calibrated gains were compared with offline calibrated gains and the results have shown that online and offline calibrated electrode gains were basically consistent.
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MOPAB090	Wavefront Distortion Measurement at SSRF	simulation, experiment, synchrotron, synchrotron-radiation	332
	B. Gao, H.J. Chen, J. Chen, Y.B. Leng, K.R. Ye SINAP, Shanghai, People's Republic of China B. Gao University of Chinese Academy of Sciences, Beijing, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	The Synchrotron Radiation Monitor (SRM) system has been designed and constructed at the Shanghai synchrotron radiation Facility (SSRF) for several years and runs good. However, the monitor extraction mirror deformation is quite common at different facilities, and other reflecting mirrors in the optic path also have surface error and angle error. As we decide to upgrade the SR monitor system at SSRF, this issue is also one of the most import thing what we should overcome. In order to verify the feasibility and evaluate the accuracy, simulations based on SRW code have been done. In this simulation, a dedicated algorithm was developed to reconstruct wavefront. The result and the algorithm is very useful for our experiment and upgrade program. In this paper, the algorithm and the experiments based on Shark-Hartmann wavefront sensor will be presented detailed.
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MOPAB111	Diffraction Radiation for Non-Invasive, High-Resolution Beam Size Measurements in Future Linear Colliders	target, simulation, collider, polarization	381
	M. Bergamaschi, R. Kieffer, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland A. Aryshev, N. Terunuma KEK, Ibaraki, Japan M. Bergamaschi, P. Karataev, K.O. Kruchinin JAI, Egham, Surrey, United Kingdom M. Bergamaschi, P. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom
	Next generation linear colliders such as the Compact Linear Collider (CLIC) or the International Linear Collider (ILC) will accelerate particle beams with extremely small emittance. The high current and small size of the beam (micron-scale) due to such small emittance require non-invasive, high-resolution techniques for beam diagnostics. Diffraction Radiation (DR), a polarization radiation that appears when a charged particle moves in the vicinity of a medium, is an ideal candidate being non-invasive and allowing beams as small as a few tens of microns to be measured. Since DR is sensitive to beam parameters other than the transverse profile (e.g. its divergence and position), preparatory simulations have been performed with realistic beam parameters. A new dedicated instrument was installed in the KEK-ATF2 beam line in February 2016. At present DR is observed in the visible wavelength range, with an upgrade to the ultraviolet (200nm) planned for spring 2017 to optimize sensitivity to smaller beam sizes. Presented here are the latest results of these DR beam size measurements and simulations.
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MOPAB118	Cherenkov Diffraction Radiation From Long Dielectric Material: An Intense Source of Photons in the NIR-THz Range	photon, electron, target, storage-ring	400
	T. Lefèvre, M. Bergamaschi, O.R. Jones, R. Kieffer, S. Mazzoni CERN, Geneva, Switzerland M.G. Billing, J.V. Conway, J.P. Shanks Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L.M. Bobb DLS, Oxfordshire, United Kingdom P. Karataev Royal Holloway, University of London, Surrey, United Kingdom
	This paper presents the design on the Cornell Electron Storage Ring (CESR) of an experimental set-up to meas-ure incoherent Diffraction Cherenkov Radiation (DChR) produced in a 2 cm long SiO2 radiator by a 2.1 GeV elec-tron beam. The electron beam is circulating at a distance of few mm from the edge of the radiator and the DChR photon output power is expected to be significantly higher than the diffraction radiation power emitted from a metal-lic slit of similar aperture. The radiator design and the detection set-up are presented in detail together with sim-ulations describing the expected properties of the emitted DChR in terms of light intensity and spectral bandwidth. Finally, potential applications of DChR are discussed.
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MOPAB126	Applications of Metamaterials for Particle Beam Diagnostics	target, electron, diagnostics, resonance	425
	T.G. Vaughan, P. Karataev JAI, Egham, Surrey, United Kingdom V. Antonov Royal Holloway, University of London, Surrey, United Kingdom V.V. Soboleva RASA Center in Tomsk, Tomsk, Russia
	Funding: The work was supported by the Leverhulme Trust through the International Network Grant (IN-2015-012) and the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 655179 and Russian Governmental Program 'Nauka', N: 0.1656.2016. Modern and future accelerators, such as linear colliders and X-ray Free Electron Lasers (X-FELs), will be capable of producing femtosecond and sub-femtosecond electron bunches with unprecedented intensity. Non-invasive beam diagnostics will be an integral component of such machines. A new non-destructive method, which employs a Left Handed Metamaterial (LHM), is promising as it provides additional flexibility in the generation and manipulation of radiation compared to techniques which use conventional materials. Simulations of the interaction of a photon beam with the LHM target have been performed using CST Microwave Studio. The range over which the frequency responce is negative can be tuned to the bunch length requirements by varying the parameters of the unit cell such as: the dimensions of the rings and the number of slits in each ring. Simulations have also been performed using Particle Studio on the interaction of an electron beam with the LHM. With a flexible resonance in the terahertz range, this material not only offers applications for ultra short bunch length measurements, but it also opens up the possibility to be used to generate coherent terahertz radiation.
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MOPAB128	The Design of a Non-Destructive Single-Shot Longitudinal Bunch Profile Monitor using Smith-Purcell Radiation	detector, background, polarization, experiment	433
	H. Harrison, G. Doucas, I.V. Konoplev, A.J. Lancaster, H. Zhang JAI, Oxford, United Kingdom A. Aryshev, M. Shevelev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Funding: This work was supported by the: the STFC UK, the Leverhulme Trust, the JAI (University of Oxford) and the Photon and Quantum Basic Research Coordinated Development (Japan). The conceptual design for a single-shot longitudinal bunch profile monitor using coherent Smith-Purcell radiation (cSPr) has recently been completed. The exploitation of the directionality and the polarization of cSPr to reduce the length of the monitor and to eliminate background radiation are discussed. The linear polarization of cSPr will be used to separate the signal from background radiation and experiments to test this design will be presented. Alongside the conceptual design an investigation to optimize the number of detection channels needed to produce high quality longitudinal bunch profile reconstructions has been carried out. It has been determined that the number of detection channels can be reduced compared to previous experiments if measurement uncertainty and background radiation are minimized effectively.
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MOPAB132	Beam Size Measurement Using High Aspect Ratio LIGA Apertures in an X-Ray Pinhole Camera	electron, synchrotron, status, emittance	445
	L.M. Bobb, G. Rehm DLS, Oxfordshire, United Kingdom
	For optimal brilliance third generation light sources operate at a low emittance and low coupling. Commonly, transverse beam profile measurements are provided by direct imaging of the electron beam using X-ray pinhole cameras. From these beam size measurements and given knowledge of the lattice parameters the emittance, coupling and energy spread are calculated. Ideally, the pinhole aperture should be formed in an infinitely thin screen. However, due to the penetration of X-rays in the keV spectral range, stacked tungsten blades are often used to form the pinhole aperture. In this arrangement the absolute size of the pinhole aperture is unknown and cannot be directly measured, which affects the spatial resolution of the imaging system. Here we investigate the use of X-ray Lithography, Electroplating and Moulding (commonly known as LIGA) to fabricate high aspect ratio pinhole apertures in a gold screen of approximately 1 mm thickness.
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MOPAB138	Comparison of Optical Transition Radiation Simulations and Theory	diagnostics, simulation, optics, electron	455
	J. Wolfenden, R.B. Fiorito, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Bergamaschi, P. Karataev, K.O. Kruchinin JAI, Egham, Surrey, United Kingdom M. Bergamaschi, P. Karataev, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom M. Bergamaschi, R. Kieffer, T. Lefèvre CERN, Geneva, Switzerland R.B. Fiorito, C.P. Welsch, J. Wolfenden The University of Liverpool, Liverpool, United Kingdom
	The majority of optical diagnostics currently used will not stand up to the requirements of the next generation of particle accelerators. Current methodologies need innovation to be able to reach the sub-micrometre resolution and sensitivity that will be required. One technique that has the potential to meet these requirements is optical transition radiation (OTR) imaging. A new algorithm is proposed which incorporates OTR theory, optical effects and beam distribution. This algorithm takes an existing method used for beam imaging and pushes the limits resolution beyond that normally attainable. In doing so, it can provide a reliable and economical diagnostic for future accelerators. A discussion on further applications of the algorithm is also presented.
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MOPAB152	Precise Synchronous Phase Measurements	storage-ring, synchrotron, synchrotron-radiation, impedance	487
	W.X. Cheng, B. Bacha, K. Ha, O. Singh BNL, Upton, Long Island, New York, USA
	Funding: DOE contract No: DE-SC0012704 Precise measurements of storage ring synchronous phase helps to understand the machine impedance and improve the high current performance. We present different methods tested at NSLS-II, including the streak camera measurement, relative phase measurement from a high sampling frequency oscilloscope by comparing the beam signal and reference signal. Both streak camera and scope method have high precision to measure the synchronous phase (<1ps). Other methods to measure the synchronous phase include the I-Q detection from BPM electronics, FPM scope have been tested as well. We have used these systems to study the synchronous phase shift at different beam current, RF voltages and ID gaps. Recent results will be presented and discussed in the paper.
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MOPIK062	Optics Adaptations for Bending Magnet Beam Lines at ESRF: Short Bend, 2-Pole Wiggler, 3-Pole Wiggler	lattice, wiggler, dipole, alignment	666
	S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, B. Nash, P. Raimondi ESRF, Grenoble, France
	The ESRF-EBS project foresees the replacement of the existing bending magnets beamlines with different radiation sources: short bend, 2-pole wiggler or 3-pole wiggler. After describing the reasons for this choices the required modifications to the storage ring lattice are described in details for each case. The study of the impact of lattice errors is also addressed, leading to the definition of beamlines' alignment tolerances.
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MOPIK078	Narrow-Band, Wide-Range Tuneable THz Source Based on the Slotted-Foil Technique	undulator, electron, simulation, FEL	712
	J. Pfingstner, E. Adli, H. Holmestad University of Oslo, Oslo, Norway S. Bettoni, S. Reiche PSI, Villigen PSI, Switzerland
	The FEL user community has expressed a strong interest in a THz source for the excitation of their samples in pump probe experiments. The demanded THz properties are challenging to achieve, as they include a narrow bandwidth of <5-10%, the possibility of frequency tuning between 1 and 20 THz, a THz pulse energy of about 100 uJ, and a fixed phase relation from shot-to-shot. To fulfil these specifications, an accelerator-based source is proposed in this paper. It utilises the slotted-foil technique to create a pre-bunched electron beam that is injected into a helical undulator. Detailed simulation studies presented in this paper show that the corresponding undulator radiation has the demanded properties.
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MOPVA001	Coherent X-Ray Radiation From Electron Beam Processed by Channeling and Emittance Exchange	electron, photon, laser, emittance	845
	I. Lobach, A.I. Benediktovitch BSU, Minsk, Belarus
	Presented contribution theoretically studies a novel scheme of compact intense x-ray radiation source. In the scheme, longitudinally modulated electron beam emits x-rays by Inverse Compton Scattering (ICS). The setup's feature is the way how longitudinal density modulation in angstrom scale is created. There are three stages of processing of initial beam of relativistic electrons: 1. First, the electrons cross a crystal plate in channeling regime. It is shown that upon leaving the crystal, the electron beam acquires discernible transverse modulation in angstrom scale. It is taken into account that not all electrons are captured in channeling mode and that some of those that do may leave it as they travel through the crystal slab. 2. Further, the beam is transported to Emittance Exchange (EEX) line, in which the direction of modulation is tilted and the beam becomes longitudinally modulated. The scale of modulation remains the same. 3. Finally, intense quasi-coherent x-ray radiation is emitted by ICS. Numerical estimations show that coherent contribution to intensity is considerable for feasible parameters of used beam, components of EEX line and laser producing photons for ICS.
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MOPVA002	Initial Stage of Self Amplified Radiation Emission From Electron Bunches in Crystal: Linear Response Theory	electron, brightness, polarization, undulator	848
	A.I. Benediktovitch, I. Lobach BSU, Minsk, Belarus, Belarus
	Self amplified spontaneous emission (SASE) is a key process in X-ray free electron lasers' operation. In this case the spontaneous emission is undulator radiation emission, the radiation in X-ray range being possible from electrons in GeV energy range. In the case of interaction of electrons with properly aligned crystal the channeling radiation results in X-rays from electrons with energies in tens MeV energy range. In this situation for high current densities the SASE process may take place that potentially could lead to construction of a compact bright X-ray source. In present contribution the first principle theoretical description is outlined and first order perturbation theory is used to model the initial stage of SASE. The transition from spontaneous to SASE regime is described, the requirements for bunch current and emittance are determined. By means of dispersion equation analysis and boundary condition application the intensity radiated from crystal slab is calculated and it is shown that Bragg diffraction could enhance self amplification. A numerical example for Si (001) illustrates the model.
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MOPVA004	Operating Simultaneously Two In-Vacuum Canted Undulators in Synchrotron SOLEIL	undulator, photon, vacuum, electron	851
	L.S. Nadolski, Y.-M. Abiven, P. Brunelle, N. Béchu, M.-E. Couprie, F.J. Cullinan, X. Delétoille, M. El Ajjouri, C. Herbeaux, N. Hubert, N. Jobert, M. Labat, J.-F. Lamarre, A. Lestrade, A. Loulergue, O. Marcouillé, P. Monteiro, A. Nadji, R. Nagaoka, D. Pédeau, P. Rommeluère, K.T. Tavakoli, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France C. Benabderrahmane ESRF, Grenoble, France
	Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with a minimum gap of 5.5 mm. The canted radiation sources are installed in a long straight section of the storage ring. The first closure of both undulators led to the severe damage of the downstream undulator in 2011. The reason for this incident has been investigated and clearly identified. A long-term project has enabled us to find a technical solution for a simultaneous operation of both undulators. A special angle fast interlock was designed and a dedicated photon absorber has been introduced at the entrance of the second undulator while keeping the impact on the beam performance as low as possible. The main technical steps will be reported with an interim solution put in place in spring 2015 and a final solution deployed and validated in May 2016.
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MOPVA018	Resonant Coherent Diffraction Radiation System at ERL Test Accelerator in KEK	cavity, resonance, experiment, emittance	887
	Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, N. Yamamoto KEK, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI Grant Number 16H05991 An Energy Recovery Linac can produce a low emittance and short bunch beam at a high repetition rate. A test accelerator, compact-ERL, has been operating in KEK for development works of technologies related to ERL and CW-Superconducting accelerators. In a special beam operation mode of bunch compression, a short bunch beam of ~150 fs at the repetition rate of CW 1.3 GHz can be realized in the return-loop. One of the promising applications of such a short bunch beam is a high power THz radiation source produced by a coherent radiation. When a charged particle beam passes close to a conductive target, a radiation called diffraction radiation is produced. If the target mirrors form an optical cavity which fundamental frequency matches the repetition frequency of the beam, the radiation resonates in the cavity, resulting in extracting a huge radiation power determined by the loss of the cavity. We plan to perform an experiment of the resonant coherent diffraction mechanism in the return-loop of the compact-ERL to test the feasibility to be a wide band high power THz source. We report the design of the experimental setup to be installed in the summer of 2017.
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MOPVA024	Investigation of the Coherent Cherenkov Radiation Using Tilted Electron Bunch	electron, target, laser, gun	905
	K. Sakaue Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan M. Brameld, M. Nishida, T. Toida, M. Washio, R. Yanagisawa Waseda University, Tokyo, Japan R. Kuroda, Y. Taira AIST, Tsukuba, Ibaraki, Japan J. Urakawa KEK, Ibaraki, Japan
	Funding: This work was supported by a research granted from The Murata Science Foundation and JSPS KAKENHI 26286083. Cherenkov radiation can be produced when the velocity of the charged particles are faster than the light in some medium. We investigated the coherent Cherenkov radiation using electron bunch tilting for matching the wave front of the Cherenkov radiation. The electron bunch was tilted by using rf transverse deflecting cavity. We tested several materials for the Cherenkov target which has enough transmittance at the wavelength of THz region. As a result, high peak power THz was achieved using this novel technique. We will report the principle of this technique, the experimental results and future prospects at the conference.
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MOPVA027	Measurement of High Power Terahertz with Dielectric Loaded Waveguide at Tsinghua University	electron, wakefield, experiment, extraction	914
	D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan TUB, Beijing, People's Republic of China S.P. Antipov Euclid Beamlabs LLC, Bolingbrook, USA Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504) We have measured an intense THz radiation produced by a sub-picosecond, relativistic electron bunch passing through a dielectric loaded waveguide (DLW) at Tsinghua University accelerator beamline. The DLW was 3 cm long quartz tube with 900 'm inner diameter and 100 'm wall thickness metallized on the outside. Radiated energy of the THz pulse was measured to be proportional to the square of the effective charge. The end of the DLW was cut at an angle for efficient THz pulse extraction. Tens of 'J THz energy per pulse were measured outside the vacuum chamber with a calibrated Golay cell in the experiment. wangdan16@mail.tsinghua.edu.cn yanlx@mail.tsinghua.edu.cn
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MOPVA041	Vertical Test Results on ESS Medium and High Beta Elliptical Cavity Prototypes Equipped with Helium Tank	cavity, linac, cryomodule, background	948
	E. Cenni CEA/IRFU, Gif-sur-Yvette, France P. Bosland, G. Devanz, F. Éozénou, X. Hanus, L. Maurice, F. Peauger, J. Plouin, D. Roudier, C. Servouin CEA/DSM/IRFU, France G. Costanza Lund University, Lund, Sweden C. Darve ESS, Lund, Sweden
	The ESS elliptical superconducting Linac consists of two types of 704.42 MHz cavities, medium and high beta, to accelerate the beam from 216 MeV (spoke cavity Linac) up to the final energy at 2 GeV. The last Linac optimization, called Optimus+, has been carried out taking into account the limitations of SRF cavity performance (field emission). The medium and high-beta parts of the Linac are composed of 36 and 84 elliptical cavities, with geometrical beta values of 0.67 and 0.86 respectively. This work presents the latest vertical test results on ESS medium and high beta elliptical cavity prototypes equipped with helium tank. We describe the cavity preparation procedure from buffer chemical polishing to vertical test.
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MOPVA061	Quench and Field Emission Diagnostics for the ESS Medium-Beta Prototypes Vertical Tests at LASA	cavity, electron, detector, diagnostics	1007
	M. Bertucci, A. Bellandi, A. Bignami, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy S. Pirani ESS, Lund, Sweden
	In order to investigate the possible causes of premature thermal breakdown and performance degradation, several diagnostic techniques have been employed during the vertical tests of the Fine and Large Grain ESS Medium Beta prototypes cavities. The whole equipment, which includes second sound, fast thermometry, photodiode x ray detectors and an external NaI scintillator, is here described and the results so far obtained during the vertical tests presented.
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MOPVA063	Vertical Tests of ESS Medium Beta Prototype Cavities at LASA	cavity, vacuum, operation, accelerating-gradient	1015
	A. Bosotti, A. Bellandi, M. Bertucci, A. Bignami, J.F. Chen, C.G. Maiano, P. Michelato, L. Monaco, R. Paparella, P. Pierini, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy S. Pirani ESS, Lund, Sweden
	In the framework of the INFN activity related to the European Spallation Source collaboration, the LASA infrastructure has been renewed to allow the qualification, in its vertical cryostat, of the 704 MHz medium beta cavity prototypes. A new cryogenic insert has been realized, fully equipped with dedicated mechanical supports, vacuum, thermal sensors and quench diagnostic systems. The RF test station has been upgraded as well with a new PLL electronics rack. The first beta 0.67 cavity prototype designed and produced by INFN Milano has been successfully cold tested at 2.0 K temperature, outperforming the ESS specifications. The technical features of LASA infrastructure, the design of novel components and the experimental results of cavities cold-tests are thoroughly described in this paper.
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MOPVA068	Experience on Design, Fabrication and Testing of a Large Grain ESS Medium Beta Prototype Cavity	cavity, niobium, operation, cryogenics	1027
	D. Sertore, A. Bellandi, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, C.G. Maiano, P. Michelato, L. Monaco, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy S. Pirani ESS, Lund, Sweden
	We report on the design, fabrication and testing of an ESS Medium Beta prototype cavity made with Large Grain Niobium sheets sliced from an ingot provided by CBMM. The peculiar choices during the fabrication process related to the Large Grain Niobium material are described. We present also the results of the cavity test at cryogenic temperature and the dedicated quench diagnostic.
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MOPVA078	The Window Replacement and Q Recovery of BEPCII Storage Ring SCC	cavity, vacuum, operation, positron	1046
	T.M. Huang, J.P. Dai, R. Ge, S.P. Li, Z.Q. Li, H.Y. Lin, Q. Ma, W.M. Pan, Y. Sun, G.W. Wang IHEP, Beijing, People's Republic of China P. Sha Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	The storage ring RF system for the upgrade of the Beijing Electron Positron Collider (BEPCII) adopted two 500 MHz superconducting cavities: west for the positron ring (BPR); east for the electron ring (BER). The excessive heating of the west window was observed in Nov.2013, and not cured thoroughly. After two years operation, the window cracked suddenly on Nov.18th, 2015. The replacement of the window was subsequently implemented in tunnel. However, the quality factor (Q) of the cavity decayed a lot after the window replacement. 90 degrees Celsius N2 gas baking of the outer surface of the cavity was carried out in situ and the Q recovered in a short time. This paper will present the process of the window replacement and the cavity Q recovery in detail. Tong-ming Huang et al., Chinese Physics C Vol. 40, No. 6 (2016) 067001
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MOPVA106	Experimental Studies of Asymmetric Dual Axis Cavity for Energy Recovery LINAC	cavity, electron, luminosity, linac	1105
	I.V. Konoplev, A.J. Lancaster, K. Metodiev, A. Seryi JAI, Oxford, United Kingdom R. Ainsworth Fermilab, Batavia, Illinois, USA G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Funding: The Leverhulme Trust via International Network Grant (IN-2015-012). Increasing the beam charge and repetition rate leads to appearance of beam break-up instabilities in conventional ERLs. At this stage the highest current, from the SRF ERL, is around 300mA. A single turn, dual axis, compact Asymmetric Energy Recovery LINAC (AERL) was proposed. The concept assumes the use of electron beams with energies up to 300 MeV and peak currents >1A, enabling the generation of high flux EUV/X-rays and THz radiation using conventional approaches. System allows beam to be transported through each stage i.e. the acceleration, interaction and deceleration only once partially removing the feedback thus increasing the instability start current. This further improved by tuning the individual cells allowing only operating mode to be uniform inside the cavity. We present the studies of 7 cells, aluminium alloy prototype of the cavity and discuss the experimental results. We show that HOMs excited on the different axis have different R/Q factors and show the field structures of operating mode and HOMs. The experimental results observed are in good agreement with theoretical predictions and the full scale copper prototype is demonstrated.
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MOPVA117	Performance of a SRF Half-Wave-Resonator Tested at Cornell for the RAON Project	cavity, simulation, SRF, pick-up	1123
	M. Ge, F. Furuta, T. Gruber, D.L. Hall, S.W. Hartman, C. Henderson, M. Liepe, S. Lok, T.I. O'Connell, P.J. Pamel, J. Sears, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA B.H. Choi, J. Joo, J.W. Kim, W.K. Kim, J. Lee, I. Shin IBS, Daejeon, Republic of Korea
	A prototype half-wave-resonator (HWR) with frequency 162.5MHz and geometrical \beta=0.12 for the RAON project is currently undergoing testing at Cornell University. Detailed vertical performance testing includes (1) test of the bare cavity without the helium tank; (2) test of the dressed cavity with helium tank. In this paper, we report on the development of the test infrastructure, test results, and performance data analysis.
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MOPVA141	Input RF Coupler Design for Energy Compensator Cavity in eRHIC	cavity, simulation, impedance, synchrotron	1184
	C. Xu, S. Bellavia, I. Ben-Zvi, M. Blaskiewicz, Y. Hao, K.S. Smith, R. Than, A. Zaltsman 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. This report gives a detail design of a 1.3 GHz input coupler for second harmonic cavity for eRHIC project. This coupler is designed to transmit 200KW CW RF to the cavity to compensate the synchrotron radiation loss. This report include RF and thermal simulation for this design.
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TUOAA3	Progress of Pr2Fe14B Based Hybrid Cryogenic Undulators at SOLEIL	undulator, cryogenics, electron, photon	1213
	A.M. Ghaith, P. Berteaud, F. Blache, F. Briquez, N. Béchu, M.-E. Couprie, J. Da Silva Castro, J.M. Dubuisson, C. Herbeaux, C.A. Kitegi, A. Lestrade, O. Marcouillé, F. Marteau, M. Sebdaoui, G. Sharma, A. Somogyi, K.T. Tavakoli, M. Tilmont, M. Valléau SOLEIL, Gif-sur-Yvette, France C. Benabderrahmane ESRF, Grenoble, France
	Cryogenic Permanent Magnet Undulators (CPMUs) take advantage of the enhanced field performance of permanent magnets when cooled down to low temperature, enabling shorter period with sufficient magnetic field to achieve high brightness radiation in the X-ray domain. Several CPMUs have been manufactured at SOLEIL. The first CPMU of period 18 mm (U18), optimized with a phase error of 3.2° at temperature of 77 K, has been installed and operated for the past 5 years at SOLEIL for the NANOSCOPIUM beamline. We report on photon beam based alignment enabling for a better adjustment of the vertical position offset of the undulator with a precision of 50 μm, and on the correction of the taper with a precision of 5 μrad to enhance the radiation flux. A second U18 cryo-ready undulator, with a new mechanical and magnetic sorting of module shimming, has attained a phase error of 2.3° at CT without any further adjustments after the assembly. Currently, two more CPMUs are being built; a 2 m long U18 for the SOLEIL ANATOMIX beamline, and a 3 m long U15 undulator reaching a magnetic gap of 3 mm. The new challenges encountered with magnetic measurements and mechanical designs for U15 are presented.
	Slides TUOAA3 [3.491 MB]
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TUOBA3	Strain and Temperature Measurements From the SNS Mercury Target Vessel During High Intensity Beam Pulses	target, simulation, data-acquisition, injection	1230
	W. Blokland, Y. Liu, B.W. Riemer, M. Wendel, D.E. Winder ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science, Scientific User Facilities. To better understand the mechanical impact of the proton beam on the lifetime on Spallation Neutron Source (SNS*) mercury-filled, stainless steel targets, these targets are now instrumented with optical and metal strain sensors, temperature sensors, and accelerometers. The strain and temperature sensors are placed inside the target vessel, between the water shroud and mercury vessel, while the accelerators are placed outside on the target mount and on the mercury return line. We now have data from four targets. The first instrumented target used regular multimode optical sensors, while later targets have used radhard multimode sensors. We are also developing super-radhard single-mode optical strain sensors to get data further into the production cycle. In this paper, we describe the data-acquisition system, compare the measured strain to the simulated strain for the different targets, estimate the survivable radiation level for each type of sensor, and discuss the implications of the results on the lifetime of the target.
	Slides TUOBA3 [37.266 MB]
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TUOAB2	First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph	background, simulation, synchrotron, photon	1244
	T.M. Mitsuhashi KEK, Ibaraki, Japan E. Bravin, F. Roncarolo, G. Trad CERN, Geneva, Switzerland
	A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.
	Slides TUOAB2 [8.302 MB]
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TUOBB3	HORIZON 2020 EuPRAXIA Design Study	plasma, laser, electron, acceleration	1265
	P.A. Walker, R.W. Aßmann, J. Bödewadt, R. Brinkmann, J. Dale, U. Dorda, A. Ferran Pousa, A.F. Habib, T. Heinemann, O. S. Kononenko, C. Lechner, B. Marchetti, A. Martinez de la Ossa, T.J. Mehrling, P. Niknejadi, J. Osterhoff, K. Poder, E.N. Svystun, G.E. Tauscher, M.K. Weikum, J. Zhu DESY, Hamburg, Germany D. Alesini, M.P. Anania, F.G. Bisesto, E. Chiadroni, M. Croia, M. Ferrario, F. Filippi, A. Gallo, A. Mostacci, R. Pompili, S. Romeo, J. Scifo, C. Vaccarezza, F. Villa INFN/LNF, Frascati (Roma), Italy A.S. Alexandrova, R.B. Fiorito, C.P. Welsch, J. Wolfenden The University of Liverpool, Liverpool, United Kingdom A.S. Alexandrova, R.B. Fiorito, C.P. Welsch, J. Wolfenden Cockcroft Institute, Warrington, Cheshire, United Kingdom N.E. Andreev, D. Pugacheva JIHT RAS, Moscow, Russia T. Audet, B. Cros, G. Maynard CNRS LPGP Univ Paris Sud, Orsay, France A. Bacci, D. Giove, V. Petrillo, A.R. Rossi, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy I.F. Barna, M.A. Pocsai Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary A. Beaton, P. Delinikolas, B. Hidding, D.A. Jaroszynski, F.Y. Li, G.G. Manahan, P. Scherkl, Z.M. Sheng, M.K. Weikum USTRAT/SUPA, Glasgow, United Kingdom A. Beck, A. Specka LLR, Palaiseau, France A. Beluze, M. Mathieu, D.N. Papadopoulos LULI, Palaiseau, France A. Bernhard, E. Bründermann, A.-S. Müller KIT, Karlsruhe, Germany S. Bielawski PhLAM/CERLA, Villeneuve d'Ascq, France F. Brandi, G. Bussolino, L.A. Gizzi, P. Koester, B. Patrizi, G. Toci, M. Vannini INO-CNR, Pisa, Italy O. Bringer, A. Chancé, O. Delferrière, J. Fils, D. Garzella, P. Gastinel, X. Li, A. Mosnier, P.A.P. Nghiem, J. Schwindling, C. Simon CEA/IRFU, Gif-sur-Yvette, France M. Büscher, A. Lehrach FZJ, Jülich, Germany M. Chen, L. Yu Shanghai Jiao Tong University, Shanghai, People's Republic of China A. Cianchi Università di Roma II Tor Vergata, Roma, Italy J.A. Clarke, N. Thompson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom M.-E. Couprie SOLEIL, Gif-sur-Yvette, France G. Dattoli, F. Nguyen ENEA C.R. Frascati, Frascati (Roma), Italy N. Delerue LAL, Orsay, France J.M. Dias, R.A. Fonseca, J.L. Martins, L.O. Silva, U. Sinha, J. Vieira IPFN, Lisbon, Portugal K. Ertel, M. Galimberti, R. Pattathil, D. Symes STFC/RAL, Chilton, Didcot, Oxon, United Kingdom J. Fils GSI, Darmstadt, Germany A. Giribono INFN-Roma, Roma, Italy L.A. Gizzi INFN-Pisa, Pisa, Italy F.J. Grüner, A.R. Maier CFEL, Hamburg, Germany F.J. Grüner, T. Heinemann, B. Hidding, O.S. Karger, A. Knetsch, A.R. Maier University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany C. Haefner LLNL, Livermore, California, USA B.J. Holzer CERN, Geneva, Switzerland S.M. Hooker University of Oxford, Clarendon Laboratory, Oxford, United Kingdom S.M. Hooker, R. Walczak JAI, Oxford, United Kingdom T. Hosokai Osaka University, Graduate School of Engineering, Osaka, Japan C. Joshi UCLA, Los Angeles, California, USA M. Kaluza HIJ, Jena, Germany S. Karsch LMU, Garching, Germany E. Khazanov, I. Kostyukov IAP/RAS, Nizhny Novgorod, Russia D. Khikhlukha, D. Kocon, G. Korn, A.Y. Molodozhentsev, L. Pribyl ELI-BEAMS, Prague, Czech Republic L. Labate, P. Tomassini CNR/IPP, Pisa, Italy W. Leemans, C.B. Schroeder LBNL, Berkeley, California, USA A. Lifschitz, V. Malka, F. Massimo LOA, Palaiseau, France V. Litvinenko BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA W. Lu TUB, Beijing, People's Republic of China V. Malka Ecole Polytechnique, Palaiseau, France S. P. D. Mangles, Z. Najmudin, A. A. Sahai Imperial College of Science and Technology, Department of Physics, London, United Kingdom A. Marocchino, A. Mostacci University of Rome La Sapienza, Rome, Italy K. Masaki, Y. Sano JAEA/Kansai, Kyoto, Japan U. Schramm HZDR, Dresden, Germany M.J.V. Streeter, A.G.R. Thomas Cockcroft Institute, Lancaster University, Lancaster, United Kingdom C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France C.-G. Wahlstrom Lund Institute of Technology (LTH), Lund University, Lund, Sweden R. Walczak Oxford University, Physics Department, Oxford, Oxon, United Kingdom G.X. Xia UMAN, Manchester, United Kingdom M. Yabashi JASRI/SPring-8, Hyogo, Japan A. Zigler The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel
	The Horizon 2020 Project EuPRAXIA ('European Plasma Research Accelerator with eXcellence In Applications') aims at producing a design report of a highly compact and cost-effective European facility with multi-GeV electron beams using plasma as the acceleration medium. The accelerator facility will be based on a laser and/or a beam driven plasma acceleration approach and will be used for photon science, high-energy physics (HEP) detector tests, and other applications such as compact X-ray sources for medical imaging or material processing. EuPRAXIA started in November 2015 and will deliver the design report in October 2019. EuPRAXIA aims to be included on the ESFRI roadmap in 2020.
	Slides TUOBB3 [9.269 MB]
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TUPAB003	High Energy Density Irradiation With MAMI LINAC	target, positron, electron, photon	1296
	P. Heil, K. Aulenbacher, Th. Beiser IKP, Mainz, Germany A. Ignatenko, G.A. Moortgat-Pick, A. Ushakov DESY, Hamburg, Germany S. Riemann DESY Zeuthen, Zeuthen, Germany
	In order to build a positron source for the ILC, a high energy density irradiation is needed to test the used materials. At the MAMI linear accelerator such a radiation can be provided at different electron energies. With a macro pulsed source it is possible to imitate a yearlong radiation at the ILC within several hours. Small transversal beam sizes need to be provided with the focusing system and be measured at high beam currents using transition radiation and current measurements.
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TUPAB006	Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC	cavity, cryomodule, operation, accelerating-gradient	1308
	Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori KEK, Ibaraki, Japan
	In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.
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TUPAB007	Analysis of the Dependability of the LHC Quench Detection System During LHC Run 2 and Further System Evolution	operation, software, electronics, superconducting-magnet	1311
	T. Podzorny, D.O. Calcoen, R. Denz, A.P. Siemko, J. Spasic, J. Steckert CERN, Geneva, Switzerland
	The quench detection system (QDS) of the LHC superconducting circuits is an essential part of the LHC machine protection and ensures the integrity of key elements of the accelerator. The large amount of hardwired and software interlock channels of the QDS requires a very high system dependability in order to reduce the risk of affecting the successful operation of the LHC. This contribution will present methods and tools for systematic fault tracking and analysis, and will discuss recent results obtained during the LHC production run in 2016. Measures for maintaining and further improving of the system performance will be explained. An overview of the further evolution of the LHC QDS also in view of the upcoming High Luminosity Upgrade of the LHC will be given.
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TUPAB020	AREAL 50 MeV Electron Accelerator Project for THz and Middle IR FEL	electron, emittance, gun, FEL	1355
	G.A. Amatuni, Z.G. Amirkhanyan, V.S. Avagyan, A. Azatyan, V. Danielyan, H. Davtyan, S.G. Dekhtiarov, N. Ghazaryan, B. Grigoryan, L. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, T. Markosyan, N. Martirosyan, Sh.A. Mehrabyan, T. Melkumyan, T.H. Mkrtchyan, V.H. Petrosyan, V. Sahakyan, A. Sargsyan, A.S. Simonyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, Ta.S. Vardanyan, T.L. Vardanyan, V. V. Vardanyan, A.S. Yeremyan, G.S. Zanyan CANDLE SRI, Yerevan, Armenia P.S. Manukyan SEUA, Yerevan, Armenia A.V. Tsakanian HZB, Berlin, Germany
	Advanced Research Electron Accelerator Laboratory (AREAL) is an electron accelerator project based on photo cathode RF gun. First phase of the facility is a 5 MeV energy RF photogun, which is currently under operation. The facility development implies energy upgrade to 50 MeV with further delivery of the electron beam to the undulator sections for Free Electron Laser and coherent undulator radiation generation in MIR and THz frequency ranges respectively. In this report the design study of AREAL 50 MeV facility main systems along with the beam dynamics and characteristics of expected radiation are presented.
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TUPAB036	Training and Characterization of 1.5m Long Conduction Cooled Superconducting Undulator Coils with 20 mm Period Length	undulator, synchrotron, vacuum, storage-ring	1399
	A.W. Grau, S. Casalbuoni, N. Glamann, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany C. Boffo, T.A. Gerhard, M. Turenne, W. Walter Babcock Noell GmbH, Wuerzburg, Germany
	The Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT), and the company Babcock Noell GmbH (BNG) are running an R&D program on superconducting undulators (SCUs). The collaboration is working on a SCU with 20 mm period length (SCU20) for ANKA, the test facility and synchrotron radiation source, run by the IBPT. The 1.5 m long undulator coils have been tested in a conduction-cooled environment. This contribution describes the training, the stability and the thermal behavior of the coils.
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TUPAB049	Development of the High Power Terahertz Light Sources at LEBRA Linac in Nihon University	target, electron, FEL, linac	1437
	T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Tanaka LEBRA, Funabashi, Japan H. Ogawa, N. Sei AIST, Tsukuba, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539. Development of a THz light source has been underway at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University in collaboration with National Institute of Advanced Industrial Science and Technology (AIST) since 2011. Basic research on coherent transition radiation (CTR) in the THz region has been carried out using the Parametric X-ray Radiation (PXR)-beam line of LEBRA. Since fiscal year 2016, the THz transport line has been constructed on the same axis as the PXR beam line taking the construction cost and simultaneous use of the two beams into account. Basic measurement and intensity upgrading test have been carried out for the THz lights generated on the PXR-generating electron beam line. The average intensity of the THz lights obtained at the output port in the accelerator room has been 5 mW. Construction of the THz transport beam line and the property of the THz lights is discussed in the report.
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TUPAB068	Design of the CPMU Vacuum System at the HEPS	vacuum, undulator, cryogenics, photon	1482
	L. Zhang, H.H. Lu, S.C. Sun IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a 3rd generation synchrotron radiation light source. Its beam energy is 6 GeV and its emittance is less than 60 pm'rad, which can provide high brilliance hard X-rays to several tens of experimental stations. The Cryogenic Permanent Magnet Undulator (CPMU) is one of the key components to achieve the high brilliance. And its vacuum system is necessary to provide an ultra-high vacuum environment for CPMU operation. To design the CPMU vacuum system, we do experiments to test the outgassing rate, estimate the total gas load, calculate the effective pumping speed, design the baking program and select all pumps and other vacuum equipments. This paper presents the design specifications and the assemblage status of the CPMU vacuum system.
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TUPAB071	Experimental Results on THz Superradiation From the Undulator in Tsinghua University Beamline	undulator, electron, detector, experiment	1488
	X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan TUB, Beijing, People's Republic of China Y.F. Liang Tsinghua University, Beijing, People's Republic of China
	In this paper, the first operation of a widely tunable 8-period undulator at terahertz (THz) frequency in Tsinghua University beamline was reported. Superradiate undulator radiation from sub-picosecond electron bunches compressed by chicane was observed. The measured radiation curve shows clearly that the radiation energy is proportional to the charge square, and the THz frequency can be changed from 0.4 THz to 10 THz with narrow-band spectrums. Our results demonstrate a high power and tunable coherent THz source, which could be useful for many applications in the future.
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TUPAB077	A Combined THz/X-ray Source Based on Brake-applied Velocity Bunching and Magnetic Compression	electron, bunching, emittance, laser	1500
	R. Huang, Z.G. He, Q.K. Jia, B. Li, W.W. Li, L. Wang, S.C. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by Chinese Universities Scientific Fund under Contracts WK2310000063 and WK2310000047 Ultrashort electron beam can be realized by the process of velocity bunching and magnetic compression. Velocity bunching technique is able to compress the bunch at relatively low energy, which presents peculiar challenges when approaching a very high current and a low transverse emittance in photoinjectors. A brake-applied velocity bunching scheme was proposed, so that the transverse emittance of the beam could be almost compensated even if the compression factor was extremely high. By adding a magnetic compressor, one could obtain a shorter beam and achieve the coherent synchrotron radiation in THz range. Meanwhile, when making the final compressed beam collide with the laser, one could acquire high energy X-ray pulses. This opens the possibility for some interesting combinations of pump-and-probe experiments.
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TUPAB087	Undulator Commissioning Experience at PAL-XFEL	undulator, electron, background, site	1520
	D.E. Kim, Y.G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh PAL, Pohang, Kyungbuk, Republic of Korea I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea J. Pflüger XFEL. EU, Hamburg, Germany
	Pohang Accelerator Laboratory (PAL) is developing a 0.1 nm SASE based FEL based on 10 GeV S-band linear accelerator named PAL-XFEL. The hard X-ray undulator line requires 20 units of 5 m long hybrid-type conventional planar undulator while soft X-ray line requires 7 units of 5 m long hybrid type planar undulators. In this report, the final measurement results of all the undulators, phase matching scheme, and the commissioning experiences will be summarized.
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TUPAB104	Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators	polarization, photon, optics, undulator	1556
	T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang NSRRC, Hsinchu, Taiwan H.W. Luo NTHU, Hsinchu, Taiwan
	While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.
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TUPAB106	Development of a Cryogenic Permanent Magnet Undulator for the TPS	undulator, vacuum, permanent-magnet, cryogenics	1562
	J.C. Huang, C.H. Chang, T.Y. Chung, C.-S. Hwang, J.C. Jan, C.S. Yang, C.K. Yang NSRRC, Hsinchu, Taiwan H. Kitamura RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	Development of a cryogenic permanent magnet undu-lator (CPMU) at the Taiwan Photon Source (TPS) is the most recent activity toward a new light source for the Phase-II beamlines. A hybrid-type CPMU with a period length of 15 mm is under construction with PrFeB permanent-magnet materials. A maximum effective magnetic field of 1.77 T at a gap of 3 mm is expected when the magnets (PMs) are cooled down around 77 K. The features desired for the TPS CPMU are low-intrinsic-phase-error characteristics and high thermal budget for various kinds of heat loads. The design of the TPS CPMU is discussed in this paper.
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TUPAB134	Life Expectancy Studies for LCLS-II Permanent Magnet Undulators	undulator, permanent-magnet, electron, optics	1640
	M. Santana-Leitner, D.E. Bruch, R.C. Field, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, M. Rowen, S.W. Score SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515 LCLSII at SLAC National Accelerator Laboratory will add a 4 GeV superconducting Linac to the existing 20 GeV Cu structure. Electron beams from the two sources going through two new variable gap undulators [] will produce FEL ranging 200-5000 keV at up to 929 kHz, also reaching 20 keV at low frequency. Such performance will be achieved by hybrid design undulators with NdFeB magnet blocks until radiation-induced demagnetization exceeds 0.01%. This is a sizable challenge, as LCLS-II will carry 120 kW beams in both its soft (SXR) and hard (HXR) beam-lines. Even small fractional losses could result excessive if too frequent or not detected and aborted fast enough. A model of SXR undulator was set for FLUKA [] radiation transport, including segments, phase-shifters, quadrupoles, RFBPM, stands/pillars and interconnecting parts. Components were installed according to MAD files, which were also used to code the optics. Beam-loss/shower propagation was simulated for beam mis-steering, interception at wire scanners and gas-bremsstrahlung interactions. Results help set limits on shut-off times, uniform loss levels and wire scanner use, and to define placement for beam loss monitors. M. Leitner et al, Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project, these proceedings ** A. Ferrari et al, The FLUKA Code: Developments and Challenges for High Energy and Medical Applications, Nuclear Data Sheets 120, 211-214 (2014)
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TUPAB140	Analysis and Correction of in-Vacuum Undulator Misalignment Effects in a Storage Ring Synchrotron Radiation Source	undulator, electron, alignment, storage-ring	1663
	O.V. Chubar, T.A. Caswell, Y. Chen-Wiegart, A. Fluerasu, Y. Hidaka, D.A. Hidas, C.A. Kitegi, M.S. Rakitin, T. Tanabe, J. Thieme, L. Wiegart, G. Williams BNL, Upton, Long Island, New York, USA
	Funding: Work was partially supported by US DOE SBIR grants DE-SC0006284 and DE-SC0011237. In-vacuum undulators (IVU) are currently very extensively used at different light source facilities, and in particular in medium-energy storage rings, for the production of high-brightness and high-flux hard X-rays. The relatively small (~5 mm or less) vertical magnetic gaps used in these planar undulators make them, however, rather sensitive to the accuracy of alignment of magnet arrays with respect to electron orbit in the vertical plane. Based on results of commissioning of a number of IVUs at hard X-ray beamlines of NSLS-II, their eventual misalignment with respect to the electron orbit was found to be among frequent reasons of spectral underperformance of the beamlines. We will present results of simulations of different IVU misalignment effects on magnetic fields seen by electron beam and on the emitted undulator radiation spectra. The simulations show e.g. that an impact of angular misalignment of an IVU on the radiation spectrum can be minimized if the IVU elevation is selected to make the electron orbit to pass through the IVU magnetic center. Experimental results of spectrum-based alignment of IVUs at hard X-ray beamlines will be presented.
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TUPIK043	Upgrade of the Neutron Dose Measurement System at BESSY	neutron, injection, electron, synchrotron	1781
	K. Ott, Y. Bergmann, M. Martin, L. Pichl HZB, Berlin, Germany
	Funding: Funded by the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie and by the Land Berlin Neutron radiation fields at synchrotron light sources are caused by bremsstrahlung from electron losses in accelerator components. Inside the enclosure and in transversal direction neutron and gamma radiation is of the same order of magnitude but high energy neutrons are much more penetrating. This causes outside the shielding neutron spectra with two broad maxima at about 1 MeV and 100 MeV. Standard Anderson-Braun or Leake neutron monitors measure thermalized neutrons in a proportional counter tube by nuclear reactions which limits the measurement range to neutron energies < 10 MeV. This implies two considerable systematic errors: Pulsed neutron beams causes dead-time losses due to the time structure of injections and the moderators are not sufficient to moderate high energy neutrons down to thermal energies. We determined and fixed these measurement errors by faster preamplifiers and by a more effective moderator developed by us, which expands the measurement range up to several GeV. Examples of the application at BESSY are presented.
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TUPIK055	Target Investigation Driven by a 10 MeV Electron Linac for Bremsstrahlung Production	target, electron, linac, photon	1819
	M. Yarmohammadi Satri, M. Lamehi, H. Shaker IPM, Tehran, Iran F. Ghasemi NSTRI, Tehran, Iran
	IPM E-Linac is a 10 MeV electron linear accelerator presently under construction at Institute for Research in Fundamental Sciences (IPM). It will accelerate electron from 45 keV to 10 MeV along the 160 cm accelerating tube. One of the beam energy measurement devices is designed based on the production of bremsstrahlung radiation. Target of the electron linac presents a key role in the production of bremsstrahlung. In this paper, we present the simulation results for an investigation on the bremsstrahlung radiation production based on target thickness, radius and atomic number, Z. We have applied Fluka Monte Carlo code for collecting the dose equiva-lent of generated bremsstrahlung along the target central axis at 30cm located downstream the target.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK055
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TUPIK071	The Novel Implementation of the Orbit Correction Algorithm for Solaris Storage Ring	TANGO, storage-ring, controls, synchrotron	1861
	P. Sagało, L.J. Dudek, A. Kisiel, G.W. Kowalski, A.I. Wawrzyniak Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland P.P. Goryl 3controls, Kraków, Poland
	The storage ring which is located in the National Synchrotron Radiation Center SOLARIS works under the TANGO control system. So far the correction of an electron beam orbit has been performed with an algorithm implemented in the Matlab Middle Layer (MML). To ensure consistency of the correction process with the entire control system, a new implementation of this algorithm has been developed. The algorithm of orbit correction based on SVD has been implemented as a TANGO Device, which is one of the fundamental blocks used in the Tango control system. The entire code has been written in the Python.
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TUPIK080	Accelerator Personnel Safety Systems for European Spallation Source	PLC, proton, linac, controls	1884
	M. Mansouri, S.L. Birch, A. Nordt, D. Paulic, Y.K. Sin, A. Toral Diez ESS, Lund, Sweden
	The European Spallation Source (ESS) is a collabora-tion of 17 European countries to build the world's most powerful neutron source for research. ESS is under con-struction since 2014 and it will produce first neutrons in 2019. The linear proton accelerator is composed of nor-mal conducting sections plus the superconducting linac. When operational, such facilities include various hazards, such as ionizing radiation, high voltage and oxygen defi-ciency. The accelerator Personal Safety System (PSS) limits exposure to them and ensures personnel safety in the accelerator tunnel. It will be developed in accordance with IEC 61508 standard (Functional Safety of Electri-cal/Electronic/Programmable Electronic Safety-related Systems), which has become a good practice in similar facilities to develop safety related systems. This paper gives an overview of the accelerator PSS and its subsys-tems. The progress of the accelerator PSS design and the selected software and hardware technologies will also be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK080
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TUPIK084	The EPICS Based Control System at the FREIA Laboratory	EPICS, controls, PLC, interface	1890
	K. Fransson, K.J. Gajewski, M. Jacewicz, M. Jobs, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden
	FREIA (Facility for REsearch and Instrumentation for Accelerator development) Laboratory at Uppsala University, Sweden, is a new facility, inaugurated 2013. Initially FREIA is testing and developing superconducting accelerating cavities and high power RF sources in collaboration with the European Spallation Source (ESS). Later projects include testing of superconducting cavities and magnets for the high luminosity LHC. The high level control, alarm system and archiving is implemented in EPICS. Presently this includes a helium liquefaction plant, a horizontal test cryostat, two high power RF amplifiers, a low level RF system, environment monitoring and safety systems. Some attention will be given to integration of commercially acquired systems as well as the safety system, interlocks and radiation monitoring. The implementation of the EPICS environment follows closely that of ESS and thus can provide a test bench for developments at ESS.
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TUPIK101	Development and Construction of Safety and Control Systems for the TPS Front End Interlock	controls, vacuum, photon, status	1947
	J. -Y. Chuang, C.K. Chan, Y.M. Hsiao, C.K. Kuan, Y.Z. Lin, I.C. Sheng, Y.C. Yang NSRRC, Hsinchu, Taiwan C.S. Lin NPUST, Pingtung, Taiwan
	The Taiwan photon source (TPS) at NSRRC (National Taiwan Photon Source) is a 3rd generation, 3 GeV storage ring with designed current of 500 mA. In phase-I, six insertion device beamlines have been available to users after the safety interlock systems were commissioned and reviewed. National Instrument (NI) compact RIO 9030 is used for the front end interlock control system, and both scan and FPGA modes are activated in a hybrid mode to enhance the safety reliability. The personnel and machine protection system as well as EPICS communications of the TPS control system are presented in this paper as well.
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TUPIK106	Analysis of the Synchrotron Radiation from Segmented Undulator in Double-Mini Beta Function	undulator, brilliance, electron, photon	1964
	H.W. Luo, C.H. Lee NTHU, Hsinchu, Taiwan T.Y. Chung, C.-S. Hwang NSRRC, Hsinchu, Taiwan C.-S. Hwang NCTU, Hsinchu, Taiwan
	Three long straight sections with double-mini beta-y lattice were created in the Taiwan Photon Source (TPS) for which the effects of focusing elements and phase shifters between the collinear undulators result in incorrect calculations of the brilliance while assuming a Gaussian-approximation. Therefore, an on-axis Wigner distribution function (WDF), which includes effects of wave phenomena, is a natural way to measure the intensity of synchrotron radiation and is used in this article as the definition of brilliance.
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TUPVA004	Synchrotron Radiation Backgrounds for the FCC-hh Experiments	photon, simulation, optics, collider	2031
	F. Collamati INFN-Roma1, Rome, Italy M. Boscolo INFN/LNF, Frascati (Roma), Italy H. Burkhardt, R. Kersevan CERN, Geneva, Switzerland
	Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305. We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.
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TUPVA006	Lessons Learnt from the 2016 LHC Run and Prospects for HL-LHC Availability	luminosity, proton, target, operation	2039
	A. Apollonio, O. Rey Orozko, R. Schmidt, M. Valette, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland
	The LHC exhibited unprecedented availability during the 2016 proton run, producing about 40 fb-1 of integrated luminosity, surpassing the sum of production during the 4 previous years. This was achieved while running steadily with a peak luminosity above the design target of 1034 cm- 2s⁻¹. Individual system performance and an increased experience operating the LHC were fundamental for these achievements, following the consolidations and improvements deployed during the Long Shutdown 1 and the Year End Technical Stop in 2015. The implications of this excellent performance in the context of the High Luminosity LHC are discussed in this paper, with the goal of defining the possible integrated luminosity reach of HL-LHC when considering the different operating conditions and the newly developed systems and technologies.
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TUPVA008	Assessment of Thermal Loads in the CERN SPS Crab Cavities Cryomodule	cavity, cryomodule, HOM, pick-up	2047
	F. Carra, J. Apeland, R. Calaga, O. Capatina, T. Capelli, C. Zanoni CERN, Geneva, Switzerland S. Verdú-Andrés BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the European Union HL-LHC Project and by US DOE through Brookhaven Science Associates LLC under contract No. DE-AC02-98CH10886 and the US LHC Accelerator Research Program (LARP). Research supported by the HL-LHC project. As a part of the HL-LHC upgrade, a cryomodule is designed to host two crab cavities for a first test with protons in the SPS machine. The evaluation of the cryomodule heat loads is essential to dimension the cryogenic infrastructure of the system. The current design features two cryogenic circuits. The first circuit adopts superfluid helium at 2 K to maintain the cavities in the superconducting state. The second circuit, based on helium gas at a temperature between 50 K and 70 K, is connected to the thermal screen, also serving as heat intercept for all the interfaces between the cold mass and the external environment. An overview of the heat loads to both circuits, and the combined numerical and analytical estimations, is presented. The heat load of each element is detailed for the static and dynamic scenarios, with considerations on the design choices for the thermal optimization of the most critical components. #Federico.carra@cern.ch*
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TUPVA011	Comparing Behaviour of Simulated Proton Synchrotron Radiation in the Arcs of the LHC with Measurements	photon, simulation, synchrotron, synchrotron-radiation	2059
	G. Guillermo Cantón, M. Ady, R. Kersevan, F. Zimmermann CERN, Geneva, Switzerland M. Angelucci, R. Cimino, E. La Francesca INFN/LNF, Frascati (Roma), Italy D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: EuCARD2 CONACyT In previous work it was shown that at high proton-beam energies, synchrotron radiation is an important source of beam-screen heating, of beam-related vacuum pressure increase, and of primary photoelectrons, which can contribute to electron cloud formation. We have used the Synrad3D code developed at Cornell to simulate the photon distributions in the arcs of the LHC, HL-LHC, and FCC-hh. Specifically, for the LHC we studied the effect of the sawtooth chamber. In this paper specific results of the Synrad3D simulations are compared with simulations in Synrad+, developed at CERN; and later on compared with experimental data for actual LHC vacuum-chamber samples.
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TUPVA015	Radiation Levels at the LHC: 2012, 2015 and 2016 Proton Physics Operations in View of HL-LHC requirements	luminosity, operation, proton, insertion	2075
	C. Martinella, M. Brugger, S. Danzeca, R. Garcia Alia, Y. Kadi, O. Stein, C. Xu CERN, Geneva, Switzerland
	The variety of beam losses produced in the Large Hadron Collider (LHC) creates a mixed and complex radiation field. During 2012, 2015 and 2016, Beam Loss Monitors and RadMons were used to monitor the inte-grated dose and the High Energy Hadrons fluence in order to anticipate the electronics degradation and inves-tigate the cause of failures. The annual radiation levels are compared; highlighting the mechanisms in the pro-duction of beam losses and the impact of the different squeeze and crossing angle. In addition, the increase of beam-gas interaction is discussed comparing operations at 25 ns and 50 ns bunch spacing. A strategy is presented to allow for a continuous respective evaluation during the upcoming LHC and future High Luminosity LHC (HL-LHC) operations.
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TUPVA016	Identification and Analysis of Prompt Dose Maxima in the Insertion Regions IR1 and IR5 of the Large Hadron Collider	luminosity, operation, dipole, quadrupole	2078
	O. Stein, M. Brugger, S. Danzeca, R. Garcia Alia, Y. Kadi, M. Kastriotou, C. Martinella, C. Xu CERN, Geneva, Switzerland
	During the operation of the LHC the continuous particle losses create a radiation field in the LHC tunnel and the adjacent caverns. Exposed electronics and accelerator components show dose dependent accelerated aging effects and stochastic Single Event Effects which can lead to faults and downtime of the LHC. In order to achieve an optimal life duration, the position of the equipment is chosen in dependency of the amplitude of the radiation fields. Therefore, it is crucial to monitor the prompt dose distributions along the whole LHC. By using the LHC beam loss monitor and RadMon systems, the prompt dose during the accelerator operation is continuously monitored. Measurements in the long straight sections and the dispersion suppressors in IR1 (ATLAS) and in IR5 (CMS) have shown that the radiation levels have localised maxima which exceed the base line by 1 to 2 orders of magnitude. The analysis of these radiation peaks will be presented and the underlying loss mechanisms will be discussed. The results will help to identify areas not suitable for radiation sensitive electronics. Implications on the expected radiation levels for High-Luminosity LHC are also discussed.
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TUPVA021	Impact of Collision Debris in the HL-LHC ATLAS and CMS Insertions	luminosity, proton, optics, insertion	2093
	A. Tsinganis, F. Cerutti CERN, Geneva, Switzerland
	The High Luminosity upgrade of the LHC (HL-LHC) foresees the baseline operation of the accelerator at a 5 times higher peak luminosity (5.0x1034cm^-2s⁻¹). The impact of collision debris on the magnets and other equipment in the triplet region and matching section of the ATLAS and CMS insertions has been evaluated by means of detailed FLUKA models implementing the latest optics and layout version. Qualitative and quantitative differences between the vertical and horizontal beam crossing schemes are highlighted. With measures in place to mitigate the effects of the interruption of the beam screen in the triplet interconnections and the Q4 aperture reduction, peak dose values in the superconducting coils remain below 30MGy in the triplet-D1 and below 12MGy in the matching section magnets for an integrated luminosity of 3000fb-1. Peak power density values are lower than 3mW/cm³ and 1mW/cm³ in the triplet and matching section respectively. Total heat loads in magnets, collimators, masks and absorbers were also estimated, along with dose and particle fluence maps relevant for Radiation to Electronics (R2E) aspects. The effect of a displacement of the interaction point is also addressed.
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TUPVA041	Exploring the Triplet Parameter Space to Optimise the Final Focus of the FCC-hh	optics, quadrupole, shielding, target	2155
	L. van Riesen-Haupt, J.L. Abelleira, E. Cruz Alaniz, A. Seryi JAI, Oxford, United Kingdom
	One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider.
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TUPVA044	Modelling and Measurements of Bunch Profiles at the LHC	emittance, synchrotron, luminosity, scattering	2167
	S. Papadopoulou, F. Antoniou, T. Argyropoulos, M. Hostettler, Y. Papaphilippou CERN, Geneva, Switzerland M. Fitterer Fermilab, Batavia, Illinois, USA
	The bunch profiles in the LHC are often observed to be non-Gaussian, both at Flat Bottom (FB) and Flat Top (FT) energies. Especially at FT, an evolution of the tail population in time is observed. In this respect, the Monte-Carlo Software for IBS and Radiation effects (SIRE) is used to track different types of beam distributions. The impact of the distribution shape on the evolution of bunch characteristics is studied. The results are compared with observations from the LHC Run 2 data.
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TUPVA048	Calculation of Particle Loss Maps for 2016 RHIC Gold-Gold Run	simulation, detector, operation, kicker	2181
	Y. Luo, K.A. Drees, W. Fischer, X. Gu, A. Marusic, G. Robert-Demolaize, 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. In the 2016 RHIC 100~GeV gold-gold (Au-Au) run, 20~mm orbit bumps were installed in the arcs to protect the experimental detectors from abort kicker prefiring. Chronic particle losses were observed in the arcs with these orbit bumps. Those particle losses are mainly from the 78+Au197 and 79+Au196 particles generated from bound-free pair production (BFPP) and electromagnetic dissociation (EMD) associated with the Au-Au collision at the IPs. In this article, we present simulated particle losses of 78+Au197 and 79+Au196 and calculate the particle loss distribution in the ring. The calculated particle loss maps are compared with operational observations.
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TUPVA114	Nuclotron New Beam Channels for Applied Researches	ion, target, heavy-ion, ion-source	2355
	E. Syresin, A.V. Butenko, O.S. Kozlov, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia A.V. Bakhmutova, A.V. Bogdanov, R. Gavrilin, A. Golubev, A.V. Kantsyrev, D.A. Liakin, N.V. Markov, V.A. Panyushkin, V. Skachkov, S.A. Visotski ITEP, Moscow, Russia
	Three new experimental areas are organized for applied physics researches in frame of realization of the accelerator facility NICA. New beamlines are under development for applied researches on Nuclotron accelerator. The ion beams with energy of 250-800 MeV/n extracted from Nuclotron will be used for the radio-biological and materials research and modeling of the cosmic rays interactions with microchips. The equipment of two experimental stations is designed by JINR-ITEP collaboration for these applied researches. The design of the magnetic system, the beam diagnostic equipment, the target stations are developed in frame of this project. The design and construction of these beamlines and experimental stations are planned in 2017-2020. Low ion energy station will be installed in 2021-2023 inside the transportation channel from heavy ion linac HILAC. Two new stations for applied researches will be constructed in 2021-2023 with ion beams at energy up 4.5 GeV/u.
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TUPVA153	Accelerator-Based Education Activities at JINR	vacuum, controls, electron, linac	2455
	M.A. Nozdrin, D. Belozerov, K. Gikal, V. Kobets, S. Pakuliak, V. Shabratov, G. Shirkov, D. Shvidkiy, K. Verlamov, A. Zhemchugov, D. Zlydenny JINR, Dubna, Moscow Region, Russia
	Professional practice is essential to train an engineer. However, many activities are impossible to run at high school, especially if they require sophisticated equipment such as accelerators. A series of practical engineering courses is being set up at the Joint Institute for Nuclear Research to overcome these difficulties while educating students from the JINR Member States. A dedicated 'training' beamline of the Linac-200 electron accelerator is being constructed to practice the beam management and diagnostics, including the operation of standard beamline elements such as a bending dipole, quadrupoles, a sextupole and steerers. Various types of particle detectors can be used in the beam area as well in order to study the passage of electrons and photons through matter and to learn about the detector operation and properties. The practice at the beam will be accompanied by a series of hands-on trainings on radiation protection, vacuum and RF technology, electronics and metrology.
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WEOCA2	Experience of Taiwan Photon Source Commissioning and Operation	vacuum, operation, injection, booster	2495
	Y.-C. Liu, C.H. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, S. Fann, C.S. Huang, C.-C. Kuo, T.Y. Lee, C.C. Liang, G.-H. Luo, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	The TPS commissioning period is from August 2014 to March 2016. The experience of phase I [1] (bare lattice 2014.8~2015.3) and phase II [2,3] (SRF and insertion devices 2015.9~2016.3) commissioning is overviewed. Taiwan Photon Source (TPS) started user operation in March 2016. The delivery user time reached 3211 hours. The continuous improvements of integrated accelerator performance are described and future developments are discussed.
	Slides WEOCA2 [32.368 MB]
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WEOCB3	The Radiation Damage in Accelerator Target Environments (RaDIATE) Collaboration R&D Program - Status and Future Activities	target, proton, experiment, status	2550
	P. Hurh Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments), founded in 2012, has grown to over 50 participants and 14 institutions globally. The primary objective is to harness existing expertise in nuclear materials and accelerator targets to generate new and useful materials data for application within the accelerator and fission/fusion communities. Current activities include post-irradiation examination of materials taken from existing beamlines (such as the NuMI beryllium primary beam window and graphite target fins from Fermilab) as well as new irradiations of candidate target materials at low energy and high energy beam facilities (such as titanium and aluminum alloys, glassy carbon, TZM and tungsten). In addition, the program includes thermal shock experiments utilizing high intensity proton beam pulses available at the HiRadMat facility at CERN. Status of current RaDIATE activities as well as future plans will be discussed, including highlights of preliminary results from various ongoing RaDIATE activities and the high level plan to explore the high-power accelerator target relevant thermal shock and radiation damage parameter space.
	Slides WEOCB3 [10.635 MB]
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WEPAB001	Parallel Operation of SASE1 and SASE3 Undulator Sections of European XFEL	undulator, simulation, kicker, operation	2554
	A. Sargsyan, V. Sahakyan CANDLE SRI, Yerevan, Armenia W. Decking DESY, Hamburg, Germany
	In the current paper the numerical simulation results for parallel (decoupled) operation of SASE1 and SASE3 undulator sections of European XFEL are presented. The study was based on the idea of betatron switcher imple-mentation. It was shown that it is possible to avoid energy spread growth in SASE1 and to reach the saturation in SASE3 in desirable range of radiation wavelengths by a trajectory kick before SASE1 and its correction before SASE3.
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WEPAB007	Pseudo Single Bunch Qualities Added to Short Pulse Operation of BESSY II	experiment, synchrotron, timing, operation	2574
	R. Müller, T. Birke, F. Falkenstern, K. Holldack, A. Jankowiak, M. Ries, A. Schälicke HZB, Berlin, Germany
	Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association BESSY II features sophisticated filling patterns as well as manipulation and separation techniques of custom bunches to serve both timing and photon hungry experiments at the same time. Recently, the low alpha operation mode, providing bunch lengths as short as 2 ps, was extended by pseudo single bunch options. A robust technique to excite one bunch with constant displacement and enlargement was implemented for pulse picking by resonant excitation (PPRE)* users. In addition, reliable scraping of an isolated bunch to provide zero current bunch length is opening new timing opportunities. The simultaneous usage of different photon characteristics: high intensity CSR, non-bursting CSR, short duration as well as operation mode specific X-rays impose new challenges. Sensitive tune measurements and feedback mechanisms had to be developed for all three dimensions. Negative alpha is in consideration to overcome the top up efficiency constraints. R. Müller et.al. BESSY II Supports an Extensive Suite of Timing Experiments, IPAC16 *K. Holldack et.al. Single bunch X-ray pulses on demand from a multi-bunch SR source, Nature Comm.5, 2014
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WEPAB009	Pilot Experiments and New Developments at the DELTA Short-Pulse Facility	laser, electron, undulator, experiment	2578
	S. Khan, B. Büsing, F. Götz, M.A. Jebramcik, N.M. Lockmann, C. Mai, A. Meyer auf der Heide, R. Niemczyk, B. Riemann, G. Shayeganrad, M. Suski, P. Ungelenk, D. Zimmermann DELTA, Dortmund, Germany U. Bovensiepen, S. Döring, A. Eschenlohr, M. Ligges, L. Plucinski, M. Plötzing, C.M. Schneider, S. Xiao Universität Duisburg-Essen, Duisburg, Germany S. Cramm Forschungszentrum Jülich, Peter-Gruenberg-Institut-6, Jülich, Germany M. Gehlmann Forschungszentrum Jülich, Peter Gruenberg Institut, Jülich, Germany
	Funding: BMBF 05K16PEA, BMBF 05K16PEB, Mercur Pr-2014-0047 At the 1.5-GeV synchrotron light source DELTA operated by the TU Dortmund University, ultrashort radiation pulses in the vacuum ultraviolet (VUV) and terahertz (THz) regime are routinely generated by the interaction of electron bunches with femtosecond laser pulses. A laser-induced energy modulation is converted into a density modulation (microbunching) by a magnetic chicane, leading to coherent emission at harmonics of the initial laser wavelength (coherent harmonic generation, CHG). Path length differences of the energy-modulated electrons along the magnetic lattice lead to a dip in the longitudinal charge distribution, which gives rise to the coherent emission of THz radiation. In first pump-probe photoemission experiments, the spatial and temporal overlap of laser pump and CHG probe pulse on the sample was demonstrated. Furthermore, the effect of two temporally separated seed pulses was studied in the VUV and (sub-)THz regime.
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WEPAB010	Progress Towards an EEHG-Based Short-Pulse Source at DELTA	electron, laser, undulator, synchrotron	2582

Paper

Title

Other Keywords

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MOOCB1

Time-Resolved Energy Spread Studies at the ANKA Storage Ring

storage-ring, timing, detector, synchrotron

53

B. Kehrer, E. Blomley, M. Brosi, E. Bründermann, A.-S. Müller, M.J. Nasse, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, N.J. Smale, J.L. Steinmann
KIT, Karlsruhe, Germany
N. Hiller
PSI, Villigen PSI, Switzerland
P. Schütze
DESY, Hamburg, Germany

Funding: This work has been supported by the Initiative and Networking Fund the Helmholtz Association under contract number VH-NG-320 and the BMBF under contract numbers 05K13VKA and 05K16VKA.
Recently, a new setup for measuring the beam energy spread has been commissioned at the ANKA storage ring at the Karlsruhe Institute of Technology. This setup is based on a fast-gated intensified camera and detects the horizontal profiles of individual bunches in a multi-bunch environment on a single-turn base. As the radiation source point is located in a dispersive section of the storage ring, this allows time-resolved studies of the energy spread. These studies are of particular interest in the framework of short-bunch beam dynamics and the characterization of instabilities. The system is fully synchronized to other beam diagnostics devices allocated in various places along the storage ring, such as the single-shot electro-optical spectral decoding setup or the turn-by-turn terahertz detection systems. Here we discuss the results of the synchronous measurements with the various systems with special emphasis on the energy spread studies.

Slides MOOCB1 [6.514 MB]

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MOPAB004

Improved Protection of the Warm Magnets of the LHC Betatron Cleaning Insertion

shielding, operation, luminosity, collimation

72

C. Bahamonde Castro, F. Cerutti, P. Fessia, A. Lechner, A. Mereghetti, D. Mirarchi, S. Redaelli, E. Skordis
CERN, Geneva, Switzerland
E. Skordis
The University of Liverpool, Liverpool, United Kingdom

After the High Luminosity (HL) upgrade in 2024-2026, the LHC is anticipated to increase its integrated luminosity by a factor of 10 beyond its original design value of 300 fb-1. In preparation for this, several improvements to the equipment will already be implemented during the next Long Shutdown (LS2) starting in 2019. In the betatron cleaning insertion, the debris leaking out of several collimators will deposit energy in the downstream warm magnets, causing long-term radiation damage. A new layout has been proposed in which the most exposed magnet of each assembly is removed, reducing the assembly from 6 to 5 magnet units and gaining 2 spare magnets. New absorbers are therefore required to enhance the shielding of the remaining magnet string. In this paper, we present an evaluation of the dose to the warm magnets for post-LS2 operation, and we quantify the achievable reduction of the long-term radiation damage for different absorber configurations. A solution for an improved magnet protection that fulfills the HL-LHC requirements is proposed.

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MOPAB021

Performance of OTR and Scintillator View Screens for the ARIEL Electron Linac

target, linac, optics, scattering

117

D.W. Storey, J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger
Victoria University, Victoria, B.C., Canada
P.S. Birney, P.E. Dirksen, S.R. Koscielniak, M. Lenckowski
TRIUMF, Vancouver, Canada

The ARIEL electron linac is a 0.3 MW CW accelerator, extensible to 0.5 MW, being installed at TRIUMF for radioactive beam production. To date, 17 view screen monitors have been installed along the beamline and have proven to be essential tools in the commissioning of e-linac systems. These are populated by two types of beam targets: P46 scintillator screens which provide diagnostics for low duty factor operation, while at locations with beam energies at and above 10 MeV, OTR foils using either Pyrolytic Graphite or Niobium foils are included to provide coverage up to 100's of μA average beam current. The design of the view screen is described including the image acquisition system and beam target selection. The performance thus far of the OTR foils under low duty factor commissioning is presented including quantification of the OTR emission distribution, thermal studies, and transmission of the beam through the linac after intercepting a foil.

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MOPAB024

Proposal to Observe Half-Bare Electrons on a 40-MeV LINAC

electron, experiment, laser, linac

126

N. Delerue, S. Jenzer, V. Khodnevych, A. Migayron
LAL, Orsay, France
N.F. Shul'ga
NSC/KIPT, Kharkov, Ukraine
S. Trofymenko
KhNU, Kharkov, Ukraine

Funding: CNRS/IN2P3 and Joint Laboratory France-Ukraine IDEATE
In different processes of relativistic electron interaction with substance and external fields, the electron loses part of its Coulomb field and becomes half-bare. Such state of electron significantly modifies the characteristics of its electromagnetic radiation during further interaction of the particle with substance. We propose to study the influence of the half-bare state of electron upon its transition radiation (TR). The existence of such influence for the case of electron undressing at its scattering was theoretically predicted. We intend to obtain the electrons in half-bare state in the result of their crossing of a conducting screen such as a TR screen. We propose to investigate the influence of the half-bare state of electron in this process upon TR generated by such electron on a downstream TR screen situated on some distance from the upstream screen which undresses the particle. Calculations are presented for the case of a 45-MeV linac and the distance between the screens in the region between 100 mm and 300 mm. The proposed experiment is expected to reveal new features of TR signal in such process comparing to previous measurements.
N.F. Shul'ga, S.V. Trofymenko, V.V. Syshchenko, JETP Lett. 93 (2011) 1.
Y. Shibata, K. Ishi, T. Tokahashi et al., Phys. Rev. E 49 (1994) 785.

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MOPAB025

Measurement of the Polarisation of Coherent Smith-Purcell Radiation in the SOLEIL Linac

polarization, detector, linac, experiment

129

N. Delerue, S. Jenzer, V. Khodnevych
LAL, Orsay, France
N. Hubert, M. Labat, J.-P. Pollina, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

Funding: CNRS/IN2P3, Université Paris-Sud and ANR (contract ANR-12-JS05-0003-01)
SPESO is an experiment installed in the Linac of Synchrotron SOLEIL to study the Coherent Smith-Purcell radiation produced when a grating is approached from the beam. The detectors used to measure this radiation are mounted on 3-translation axis and 2 rotation axis. This allows measurements of the radiation emission map around the grating. In addition a polarizer has been added in 2016 allowing to study the two polarization components of the radiation in this map. Preliminary results of this mapping will be presented.

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MOPAB026

Study of a Smith-Purcell Radiation-Based Longitudinal Profile Monitor at the CLIO Free Electron Laser

electron, laser, free-electron-laser, detector

132

V. Khodnevych, N. Delerue, S. Jenzer, H. Roesch
LAL, Orsay, France
J.P. Berthet, F. Glotin, J.-M. Ortega, R. Prazeres
LCP/CLIO, Orsay, Cedex, France
N. Jestin
CLIO/ELISE/LCP, Orsay, France

Funding: CNRS and ANR (contract ANR-12-JS05-0003-01)
We report on measurements of Coherent Smith-Purcell radiation at the CLIO Free Electron Laser. Smith-Purcell radiation is emitted when a grating is brought close from a bunch of relativistic particles. When the bunch is sufficiently short coherent radiation is emitted. This coherent radiation encodes the longitudinal form factor of the bunch and can therefore be used as a longitudinal profile monitor. With its short pulses and high charge the 45 MeV Linac of CLIO is a good location to test advanced longitudinal profile diag- nostics. The results will be compared with measurements using the RF dephasing. induced energy dispersion.

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MOPAB032

Status of a Double Slit Interferometer for Transverse Beam Size Measurements at BESSY II

diagnostics, storage-ring, synchrotron, operation

149

M. Koopmans, P. Goslawski, J.G. Hwang, M. Ries, M. Ruprecht, A. Schälicke
HZB, Berlin, Germany

Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association
The upgrade of the BESSY II storage ring to BESSY VSR* demands additional beam diagnostics for machine commissioning and development. Especially bunch resolved measurements are needed. Currently, transverse beam size measurements are done with X-ray pinhole monitor systems, which cannot provide bunch resolved information. Alternative methods to measure the transverse beam size using synchrotron radiation in the visible spectrum are interferometric techniques, which could also be upgraded to bunch resolved systems. For that purpose a double slit interferometer has been constructed. Commissioning of the system has started and experimental results are discussed and compared with the existing pinhole system.
* A. Jankowiak et al., eds., ''BESSY VSR - Technical Design Study'', Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany, June 2015.

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MOPAB042

Two-Dimensional Synchrotron Radiation Interferometry at PETRA III

synchrotron, emittance, synchrotron-radiation, operation

177

A.I. Novokshonov, A. Potylitsyn
TPU, Tomsk, Russia
G. Kube
DESY, Hamburg, Germany

Synchrotron radiation interferometry is widely used at modern 3rd generation light sources in order to measure transverse electron beam sizes. The technique is based on probing of the spatial coherency of synchrotron radiation in the visible spectral region. The light source PETRA III at DESY (Hamburg, Germany) is using this type of interferometer since several years in order to resolve vertical emittances of about 10 pm.rad. In order to overcome some inherent disadvantages in this setup, a new optical diagnostics beamline was recently commissioned with a two-dimensional interferometer, thus allowing to measure beam sizes in both transverse planes simultaneously. This contribution summarizes the status of the interferometer with first operational experience and describes systematical studies concerning the stability and possibilities to increase the sensitivity on small beam sizes using an intensity imbalance technique.

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MOPAB055

Towards Near-Field Electro-Optical Bunch Profile Monitoring in a Multi-Bunch Environment

electron, wakefield, laser, storage-ring

227

P. Schönfeldt, E. Blomley, E. Bründermann, M. Caselle, S. Funkner, N. Hiller, B. Kehrer, A.-S. Müller, M.J. Nasse, G. Niehues, L. Rota, M. Schedler, M. Schuh, M. Weber
KIT, Karlsruhe, Germany

Funding: This work is funded by the BMBF contract numbers: 05K13VKA and 05K16VKA.
For electron accelerators, electro-optical methods in the near-field have been shown to be a powerful tool to detect longitudinal bunch profiles. In 2013, we demonstrated for the first time, electro-optical bunch profile measurements in a storage ring at the accelerator test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT). To study possible bunch-bunch interactions and its effects on the longitudinal dynamics, these measurements need to be performed in a multi-bunch environment. Up to now, due to long-ranging wake-fields the electro-optical monitoring was limited to single-bunch operation. Here, we present our new in-vacuum setup to overcome this limitation. First measurements show reduced wake-fields in particular around 2 ns, where the subsequent bunch can occur in a multi-bunch environment at ANKA.

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MOPAB056

4-Channel Single Shot and Turn-by-Turn Spectral Measurements of Bursting CSR

detector, synchrotron, simulation, storage-ring

231

J.L. Steinmann, E. Blomley, M. Brosi, E. Bründermann, M. Caselle, B. Kehrer, A.-S. Müller, L. Rota, M. Schuh, P. Schönfeldt, M. Siegel, M. Weber
KIT, Karlsruhe, Germany

The test facility and synchrotron radiation source ANKA at the Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany, can be operated in a short-bunch mode. Above a threshold current, the high charge density leads to microwave instabilities and the formation of sub-structures. These time-varying sub-structures on bunches of picosecond duration lead to the observation of bursting coherent synchrotron radiation (CSR) in the terahertz (THz) frequency range. The spectral information in this range contains valuable information about the bunch length, shape and sub-structures. We present recent measurements of a spectrometer setup that consists of 4 ultra-fast THz detectors, sensitive in different frequency bands, combined with the KAPTURE readout system developed at KIT for studies requiring high data throughput. This setup allows to record continuously the spectral information on a bunch-by-bunch and turn-by-turn basis. This contribution describes the potential of time-resolved spectral measurements of the short-bunch beam dynamics.

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MOPAB060

Thermal Issues for the Optical Transition Radiation Screen for the ELI-NP Compton Gamma Source

electron, target, simulation, laser

246

F. Cioeta, D. Alesini, A. Falone, V.L. Lollo, L. Pellegrino, A. Variola
INFN/LNF, Frascati (Roma), Italy
M. Ciambrella
University of Rome La Sapienza, Rome, Italy
D. Cortis, M. Marongiu, V. Pettinacci
INFN-Roma, Roma, Italy
A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy

A high brightness electron Linac is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with the laser beam in two interaction points. Electron beam spot size is measured with optical transition radiation (OTR) profile monitors. In order to measure the beam properties, the OTR screens must sustain the thermal and mechanical stress due to the energy deposited by the bunches. This paper is an ANSYS study of the issues due to the high energy transferred to the OTR screens. Thermal multicycle analysis will be shown; each analysis will be followed by a structural analysis in order to investigate the performance of the material. The multiphysics analysis will be extended to the mechanical contact areas with the target frame in order to evaluate the order of magnitude of the phenomena in those regions.

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MOPAB066

Development and Performance Test of the BPM System for the SPring-8 Upgrade

simulation, storage-ring, electron, photon

265

H. Maesaka
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
H. Dewa, T. Fujita, M. Masaki
JASRI, Hyogo, Japan
S. Takano
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan

We are developing a stable and precise BPM system for the low-emittance upgrade of SPring-8. One of the essential requirements for the BPM is the long term stabilization of the photon beam by regulating the electron beam orbit. Both the single-pass resolution of 100 um rms for an injected beam charge of 100 pC and an accuracy of 100 um rms are also crucial for beam commissioning. Drift sources of the present BPM system have been investigated extensively, such as humidity-dependent drifts coming from the radiation damage of coaxial cables, and the results are fed back to the design of the new BPM system. We have optimized the design of the button BPM electrodes to reconcile reduction of trapped-mode heating and maximization of the signal intensity. Stringent machining tolerance is imposed on a BPM head to align the BPM electric center accurately. A few kinds of the BPM head prototypes were produced and the machining accuracy, RF characteristics etc. were confirmed to be sufficient. We have installed one of the prototypes in the present storage ring to test the performance of the new BPM system under development, and have been obtaining successful results satisfying the requirements.

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MOPAB073

Measurement of Electron-Bunch Length Using Coherent Radiation in Infrared Free-Electron Laser Facilities

electron, FEL, detector, laser

288

N. Sei, H. Ogawa
AIST, Tsukuba, Ibaraki, Japan
K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, T. Tanaka
LEBRA, Funabashi, Japan
H. Ohgaki, H. Zen
Kyoto University, Kyoto, Japan

Funding: This study was financially supported by JSPS KAKENHI Grant Number JP16H03912.
We have studied techniques evaluating bunch length of micropulses in an electron beam. The bunch length of the electron beam is an important parameter for free-electron laser (FEL) facilities with linear accelerators. In order to obtain high FEL gain at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University and at Kyoto University Free Electron Laser (KU-FEL), the electron-bunch length is compressed to less than 1 ps in their undulator sections. Using the compressed electron beams, intense terahertz lights were generated by coherent radiation. The power of the coherent radiation was more than 50 micro-joule per electron-beam macropulse. We can extract the information of the bunch length of the electron-beam micropulse from the intense coherent radiation by using narrow-band diode detectors. In this presentation, experimental results of the measurements of the root-mean-square electron-bunch length using the coherent radiation at LEBRA* and KU-FEL** will be reported.
*: N. Sei et al., J. Opt. Soc. Am. B, 31, 2150 (2014).
**: N. Sei et al., Nucl. Instrum. Methods Phys. Res., Sect. A, 832, 208 (2016).

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MOPAB075

Measurement of Electron Bunch Length via a Tunable-Gap Undulator

electron, undulator, laser, acceleration

295

X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan
TUB, Beijing, People's Republic of China
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

A THz undulator with widely tunable gap is constructed and installed at Tsinghua University beamline, which is applied for narrow-band THz radiation and measurements of electron bunch longitudinal structure. This is a planar electromagnetic device with 8 regular periods, each 10 cm long. The field range B=0.15- 0.99 T peak field on axis while changing the gap from 75mm to 23mm. In the experiments, we scanned the undulator gap to measure the radiation intensity at different resonant frequency, thus we can get the bunch length even form factor of the bunch. The demonstrated experimental results show that the bunch of 220pC compressed by chicane in Tsinghua beamline is about 120fs (rms), which agree well with the simulations. The resolution of bunch length measurement with this method can be attoseconds by optimized undulator. Furthermore, the form factor of electron bunch train can also be measured.

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MOPAB076

2D Beam Profile Monitors at CPHS of Tsinghua University

proton, target, ion, electronics

298

W. Wang, X. Guan, W.-H. Huang, Y. Lei, X.W. Wang, Q.Z. Xing, S.X. Zheng
TUB, Beijing, People's Republic of China
L. Du
CEA/IRFU, Gif-sur-Yvette, France
M.T. Qiu, Z.M. Wang
State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Shannxi, People's Republic of China

Beam profile is a key parameter for high current proton linac. Compact Pulsed Hadron Source(CPHS) has two type of detectors to monitor beam 2D beam profile: scintillator screen and rotatable multi-wire scanner. A retractable chromium-doped alumina (Chromox) screen is used as scintillator, emitted lights when impacted by proton are captured by a 12 bit CCD camera. Nineteen carbon fibre wires with a diameter of 30 'm, 3 mm separated from each other, are used to measure beam 1D distribution. Projection can be measured at different direction by rotating the multi-wire scanner about beam direction. 2D beam distribution is reconstructed from multiple projections with the help of CT. Different CT algorithms, Algebra Reconstruct Technique (ART) and Maximum Entropy algorithm (MENT), are applied to achieve accurate or quick reconstruction. The preliminary experimental results show the two profile monitors working consistently with each other.

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MOPAB084

Online Measurement of Electrode Gains for Stripline Beam Position Monitor in the HLS II Storage Ring

storage-ring, quadrupole, site, operation

316

F.F. Wu, L. Lin, X.Y. Liu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang, J.H. Wei, Y.L. Yang, T.Y. Zhou, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Supported by the National Key Research and Development Program of China(No. 2016YFA0402000) and the National Science Foundation of China (11575181, 11605202)
Three axially symmetric stripline beam position monitors were installed in the HLS II storage ring and each stripline BPM was machined with button BPM together. Due to mechanical errors of stripline BPM, differences in electrode gains will lead to measurement error for beam position and mutual coupling between beam horizontal position and vertical position. So it is very important to calibrate electrode gains for axially symmetric BPM. A method was proposed to calibrate electrode gains of this kind of BPM. This method is suitable for all axially symmetric BPMs, whether stripline BPM or button BPM. The online calibrated gains were compared with offline calibrated gains and the results have shown that online and offline calibrated electrode gains were basically consistent.

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MOPAB090

Wavefront Distortion Measurement at SSRF

simulation, experiment, synchrotron, synchrotron-radiation

332

B. Gao, H.J. Chen, J. Chen, Y.B. Leng, K.R. Ye
SINAP, Shanghai, People's Republic of China
B. Gao
University of Chinese Academy of Sciences, Beijing, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

The Synchrotron Radiation Monitor (SRM) system has been designed and constructed at the Shanghai synchrotron radiation Facility (SSRF) for several years and runs good. However, the monitor extraction mirror deformation is quite common at different facilities, and other reflecting mirrors in the optic path also have surface error and angle error. As we decide to upgrade the SR monitor system at SSRF, this issue is also one of the most import thing what we should overcome. In order to verify the feasibility and evaluate the accuracy, simulations based on SRW code have been done. In this simulation, a dedicated algorithm was developed to reconstruct wavefront. The result and the algorithm is very useful for our experiment and upgrade program. In this paper, the algorithm and the experiments based on Shark-Hartmann wavefront sensor will be presented detailed.

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MOPAB111

Diffraction Radiation for Non-Invasive, High-Resolution Beam Size Measurements in Future Linear Colliders

target, simulation, collider, polarization

381

M. Bergamaschi, R. Kieffer, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland
A. Aryshev, N. Terunuma
KEK, Ibaraki, Japan
M. Bergamaschi, P. Karataev, K.O. Kruchinin
JAI, Egham, Surrey, United Kingdom
M. Bergamaschi, P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom

Next generation linear colliders such as the Compact Linear Collider (CLIC) or the International Linear Collider (ILC) will accelerate particle beams with extremely small emittance. The high current and small size of the beam (micron-scale) due to such small emittance require non-invasive, high-resolution techniques for beam diagnostics. Diffraction Radiation (DR), a polarization radiation that appears when a charged particle moves in the vicinity of a medium, is an ideal candidate being non-invasive and allowing beams as small as a few tens of microns to be measured. Since DR is sensitive to beam parameters other than the transverse profile (e.g. its divergence and position), preparatory simulations have been performed with realistic beam parameters. A new dedicated instrument was installed in the KEK-ATF2 beam line in February 2016. At present DR is observed in the visible wavelength range, with an upgrade to the ultraviolet (200nm) planned for spring 2017 to optimize sensitivity to smaller beam sizes. Presented here are the latest results of these DR beam size measurements and simulations.

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MOPAB118

Cherenkov Diffraction Radiation From Long Dielectric Material: An Intense Source of Photons in the NIR-THz Range

photon, electron, target, storage-ring

400

T. Lefèvre, M. Bergamaschi, O.R. Jones, R. Kieffer, S. Mazzoni
CERN, Geneva, Switzerland
M.G. Billing, J.V. Conway, J.P. Shanks
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb
DLS, Oxfordshire, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom

This paper presents the design on the Cornell Electron Storage Ring (CESR) of an experimental set-up to meas-ure incoherent Diffraction Cherenkov Radiation (DChR) produced in a 2 cm long SiO2 radiator by a 2.1 GeV elec-tron beam. The electron beam is circulating at a distance of few mm from the edge of the radiator and the DChR photon output power is expected to be significantly higher than the diffraction radiation power emitted from a metal-lic slit of similar aperture. The radiator design and the detection set-up are presented in detail together with sim-ulations describing the expected properties of the emitted DChR in terms of light intensity and spectral bandwidth. Finally, potential applications of DChR are discussed.

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MOPAB126

Applications of Metamaterials for Particle Beam Diagnostics

target, electron, diagnostics, resonance

425

T.G. Vaughan, P. Karataev
JAI, Egham, Surrey, United Kingdom
V. Antonov
Royal Holloway, University of London, Surrey, United Kingdom
V.V. Soboleva
RASA Center in Tomsk, Tomsk, Russia

Funding: The work was supported by the Leverhulme Trust through the International Network Grant (IN-2015-012) and the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 655179 and Russian Governmental Program 'Nauka', N: 0.1656.2016.
Modern and future accelerators, such as linear colliders and X-ray Free Electron Lasers (X-FELs), will be capable of producing femtosecond and sub-femtosecond electron bunches with unprecedented intensity. Non-invasive beam diagnostics will be an integral component of such machines. A new non-destructive method, which employs a Left Handed Metamaterial (LHM), is promising as it provides additional flexibility in the generation and manipulation of radiation compared to techniques which use conventional materials. Simulations of the interaction of a photon beam with the LHM target have been performed using CST Microwave Studio. The range over which the frequency responce is negative can be tuned to the bunch length requirements by varying the parameters of the unit cell such as: the dimensions of the rings and the number of slits in each ring. Simulations have also been performed using Particle Studio on the interaction of an electron beam with the LHM. With a flexible resonance in the terahertz range, this material not only offers applications for ultra short bunch length measurements, but it also opens up the possibility to be used to generate coherent terahertz radiation.

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MOPAB128

The Design of a Non-Destructive Single-Shot Longitudinal Bunch Profile Monitor using Smith-Purcell Radiation

detector, background, polarization, experiment

433

H. Harrison, G. Doucas, I.V. Konoplev, A.J. Lancaster, H. Zhang
JAI, Oxford, United Kingdom
A. Aryshev, M. Shevelev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Funding: This work was supported by the: the STFC UK, the Leverhulme Trust, the JAI (University of Oxford) and the Photon and Quantum Basic Research Coordinated Development (Japan).
The conceptual design for a single-shot longitudinal bunch profile monitor using coherent Smith-Purcell radiation (cSPr) has recently been completed. The exploitation of the directionality and the polarization of cSPr to reduce the length of the monitor and to eliminate background radiation are discussed. The linear polarization of cSPr will be used to separate the signal from background radiation and experiments to test this design will be presented. Alongside the conceptual design an investigation to optimize the number of detection channels needed to produce high quality longitudinal bunch profile reconstructions has been carried out. It has been determined that the number of detection channels can be reduced compared to previous experiments if measurement uncertainty and background radiation are minimized effectively.

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MOPAB132

Beam Size Measurement Using High Aspect Ratio LIGA Apertures in an X-Ray Pinhole Camera

electron, synchrotron, status, emittance

445

L.M. Bobb, G. Rehm
DLS, Oxfordshire, United Kingdom

For optimal brilliance third generation light sources operate at a low emittance and low coupling. Commonly, transverse beam profile measurements are provided by direct imaging of the electron beam using X-ray pinhole cameras. From these beam size measurements and given knowledge of the lattice parameters the emittance, coupling and energy spread are calculated. Ideally, the pinhole aperture should be formed in an infinitely thin screen. However, due to the penetration of X-rays in the keV spectral range, stacked tungsten blades are often used to form the pinhole aperture. In this arrangement the absolute size of the pinhole aperture is unknown and cannot be directly measured, which affects the spatial resolution of the imaging system. Here we investigate the use of X-ray Lithography, Electroplating and Moulding (commonly known as LIGA) to fabricate high aspect ratio pinhole apertures in a gold screen of approximately 1 mm thickness.

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MOPAB138

Comparison of Optical Transition Radiation Simulations and Theory

diagnostics, simulation, optics, electron

455

J. Wolfenden, R.B. Fiorito, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Bergamaschi, P. Karataev, K.O. Kruchinin
JAI, Egham, Surrey, United Kingdom
M. Bergamaschi, P. Karataev, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
M. Bergamaschi, R. Kieffer, T. Lefèvre
CERN, Geneva, Switzerland
R.B. Fiorito, C.P. Welsch, J. Wolfenden
The University of Liverpool, Liverpool, United Kingdom

The majority of optical diagnostics currently used will not stand up to the requirements of the next generation of particle accelerators. Current methodologies need innovation to be able to reach the sub-micrometre resolution and sensitivity that will be required. One technique that has the potential to meet these requirements is optical transition radiation (OTR) imaging. A new algorithm is proposed which incorporates OTR theory, optical effects and beam distribution. This algorithm takes an existing method used for beam imaging and pushes the limits resolution beyond that normally attainable. In doing so, it can provide a reliable and economical diagnostic for future accelerators. A discussion on further applications of the algorithm is also presented.

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MOPAB152

Precise Synchronous Phase Measurements

storage-ring, synchrotron, synchrotron-radiation, impedance

487

W.X. Cheng, B. Bacha, K. Ha, O. Singh
BNL, Upton, Long Island, New York, USA

Funding: DOE contract No: DE-SC0012704
Precise measurements of storage ring synchronous phase helps to understand the machine impedance and improve the high current performance. We present different methods tested at NSLS-II, including the streak camera measurement, relative phase measurement from a high sampling frequency oscilloscope by comparing the beam signal and reference signal. Both streak camera and scope method have high precision to measure the synchronous phase (<1ps). Other methods to measure the synchronous phase include the I-Q detection from BPM electronics, FPM scope have been tested as well. We have used these systems to study the synchronous phase shift at different beam current, RF voltages and ID gaps. Recent results will be presented and discussed in the paper.

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MOPIK062

Optics Adaptations for Bending Magnet Beam Lines at ESRF: Short Bend, 2-Pole Wiggler, 3-Pole Wiggler

lattice, wiggler, dipole, alignment

666

S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, B. Nash, P. Raimondi
ESRF, Grenoble, France

The ESRF-EBS project foresees the replacement of the existing bending magnets beamlines with different radiation sources: short bend, 2-pole wiggler or 3-pole wiggler. After describing the reasons for this choices the required modifications to the storage ring lattice are described in details for each case. The study of the impact of lattice errors is also addressed, leading to the definition of beamlines' alignment tolerances.

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MOPIK078

Narrow-Band, Wide-Range Tuneable THz Source Based on the Slotted-Foil Technique

undulator, electron, simulation, FEL

712

J. Pfingstner, E. Adli, H. Holmestad
University of Oslo, Oslo, Norway
S. Bettoni, S. Reiche
PSI, Villigen PSI, Switzerland

The FEL user community has expressed a strong interest in a THz source for the excitation of their samples in pump probe experiments. The demanded THz properties are challenging to achieve, as they include a narrow bandwidth of <5-10%, the possibility of frequency tuning between 1 and 20 THz, a THz pulse energy of about 100 uJ, and a fixed phase relation from shot-to-shot. To fulfil these specifications, an accelerator-based source is proposed in this paper. It utilises the slotted-foil technique to create a pre-bunched electron beam that is injected into a helical undulator. Detailed simulation studies presented in this paper show that the corresponding undulator radiation has the demanded properties.

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MOPVA001

Coherent X-Ray Radiation From Electron Beam Processed by Channeling and Emittance Exchange

electron, photon, laser, emittance

845

I. Lobach, A.I. Benediktovitch
BSU, Minsk, Belarus

Presented contribution theoretically studies a novel scheme of compact intense x-ray radiation source. In the scheme, longitudinally modulated electron beam emits x-rays by Inverse Compton Scattering (ICS). The setup's feature is the way how longitudinal density modulation in angstrom scale is created. There are three stages of processing of initial beam of relativistic electrons: 1. First, the electrons cross a crystal plate in channeling regime. It is shown that upon leaving the crystal, the electron beam acquires discernible transverse modulation in angstrom scale. It is taken into account that not all electrons are captured in channeling mode and that some of those that do may leave it as they travel through the crystal slab. 2. Further, the beam is transported to Emittance Exchange (EEX) line, in which the direction of modulation is tilted and the beam becomes longitudinally modulated. The scale of modulation remains the same. 3. Finally, intense quasi-coherent x-ray radiation is emitted by ICS. Numerical estimations show that coherent contribution to intensity is considerable for feasible parameters of used beam, components of EEX line and laser producing photons for ICS.

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MOPVA002

Initial Stage of Self Amplified Radiation Emission From Electron Bunches in Crystal: Linear Response Theory

electron, brightness, polarization, undulator

848

A.I. Benediktovitch, I. Lobach
BSU, Minsk, Belarus, Belarus

Self amplified spontaneous emission (SASE) is a key process in X-ray free electron lasers' operation. In this case the spontaneous emission is undulator radiation emission, the radiation in X-ray range being possible from electrons in GeV energy range. In the case of interaction of electrons with properly aligned crystal the channeling radiation results in X-rays from electrons with energies in tens MeV energy range. In this situation for high current densities the SASE process may take place that potentially could lead to construction of a compact bright X-ray source. In present contribution the first principle theoretical description is outlined and first order perturbation theory is used to model the initial stage of SASE. The transition from spontaneous to SASE regime is described, the requirements for bunch current and emittance are determined. By means of dispersion equation analysis and boundary condition application the intensity radiated from crystal slab is calculated and it is shown that Bragg diffraction could enhance self amplification. A numerical example for Si (001) illustrates the model.

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MOPVA004

Operating Simultaneously Two In-Vacuum Canted Undulators in Synchrotron SOLEIL

undulator, photon, vacuum, electron

851

L.S. Nadolski, Y.-M. Abiven, P. Brunelle, N. Béchu, M.-E. Couprie, F.J. Cullinan, X. Delétoille, M. El Ajjouri, C. Herbeaux, N. Hubert, N. Jobert, M. Labat, J.-F. Lamarre, A. Lestrade, A. Loulergue, O. Marcouillé, P. Monteiro, A. Nadji, R. Nagaoka, D. Pédeau, P. Rommeluère, K.T. Tavakoli, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France
C. Benabderrahmane
ESRF, Grenoble, France

Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with a minimum gap of 5.5 mm. The canted radiation sources are installed in a long straight section of the storage ring. The first closure of both undulators led to the severe damage of the downstream undulator in 2011. The reason for this incident has been investigated and clearly identified. A long-term project has enabled us to find a technical solution for a simultaneous operation of both undulators. A special angle fast interlock was designed and a dedicated photon absorber has been introduced at the entrance of the second undulator while keeping the impact on the beam performance as low as possible. The main technical steps will be reported with an interim solution put in place in spring 2015 and a final solution deployed and validated in May 2016.

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MOPVA018

Resonant Coherent Diffraction Radiation System at ERL Test Accelerator in KEK

cavity, resonance, experiment, emittance

887

Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, N. Yamamoto
KEK, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI Grant Number 16H05991
An Energy Recovery Linac can produce a low emittance and short bunch beam at a high repetition rate. A test accelerator, compact-ERL, has been operating in KEK for development works of technologies related to ERL and CW-Superconducting accelerators. In a special beam operation mode of bunch compression, a short bunch beam of ~150 fs at the repetition rate of CW 1.3 GHz can be realized in the return-loop. One of the promising applications of such a short bunch beam is a high power THz radiation source produced by a coherent radiation. When a charged particle beam passes close to a conductive target, a radiation called diffraction radiation is produced. If the target mirrors form an optical cavity which fundamental frequency matches the repetition frequency of the beam, the radiation resonates in the cavity, resulting in extracting a huge radiation power determined by the loss of the cavity. We plan to perform an experiment of the resonant coherent diffraction mechanism in the return-loop of the compact-ERL to test the feasibility to be a wide band high power THz source. We report the design of the experimental setup to be installed in the summer of 2017.

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MOPVA024

Investigation of the Coherent Cherenkov Radiation Using Tilted Electron Bunch

electron, target, laser, gun

905

K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
M. Brameld, M. Nishida, T. Toida, M. Washio, R. Yanagisawa
Waseda University, Tokyo, Japan
R. Kuroda, Y. Taira
AIST, Tsukuba, Ibaraki, Japan
J. Urakawa
KEK, Ibaraki, Japan

Funding: This work was supported by a research granted from The Murata Science Foundation and JSPS KAKENHI 26286083.
Cherenkov radiation can be produced when the velocity of the charged particles are faster than the light in some medium. We investigated the coherent Cherenkov radiation using electron bunch tilting for matching the wave front of the Cherenkov radiation. The electron bunch was tilted by using rf transverse deflecting cavity. We tested several materials for the Cherenkov target which has enough transmittance at the wavelength of THz region. As a result, high peak power THz was achieved using this novel technique. We will report the principle of this technique, the experimental results and future prospects at the conference.

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MOPVA027

Measurement of High Power Terahertz with Dielectric Loaded Waveguide at Tsinghua University

electron, wakefield, experiment, extraction

914

D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan
TUB, Beijing, People's Republic of China
S.P. Antipov
Euclid Beamlabs LLC, Bolingbrook, USA
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504)
We have measured an intense THz radiation produced by a sub-picosecond, relativistic electron bunch passing through a dielectric loaded waveguide (DLW) at Tsinghua University accelerator beamline. The DLW was 3 cm long quartz tube with 900 'm inner diameter and 100 'm wall thickness metallized on the outside. Radiated energy of the THz pulse was measured to be proportional to the square of the effective charge. The end of the DLW was cut at an angle for efficient THz pulse extraction. Tens of 'J THz energy per pulse were measured outside the vacuum chamber with a calibrated Golay cell in the experiment.
*wangdan16@mail.tsinghua.edu.cn
*yanlx@mail.tsinghua.edu.cn

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MOPVA041

Vertical Test Results on ESS Medium and High Beta Elliptical Cavity Prototypes Equipped with Helium Tank

cavity, linac, cryomodule, background

948

E. Cenni
CEA/IRFU, Gif-sur-Yvette, France
P. Bosland, G. Devanz, F. Éozénou, X. Hanus, L. Maurice, F. Peauger, J. Plouin, D. Roudier, C. Servouin
CEA/DSM/IRFU, France
G. Costanza
Lund University, Lund, Sweden
C. Darve
ESS, Lund, Sweden

The ESS elliptical superconducting Linac consists of two types of 704.42 MHz cavities, medium and high beta, to accelerate the beam from 216 MeV (spoke cavity Linac) up to the final energy at 2 GeV. The last Linac optimization, called Optimus+, has been carried out taking into account the limitations of SRF cavity performance (field emission). The medium and high-beta parts of the Linac are composed of 36 and 84 elliptical cavities, with geometrical beta values of 0.67 and 0.86 respectively. This work presents the latest vertical test results on ESS medium and high beta elliptical cavity prototypes equipped with helium tank. We describe the cavity preparation procedure from buffer chemical polishing to vertical test.

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MOPVA061

Quench and Field Emission Diagnostics for the ESS Medium-Beta Prototypes Vertical Tests at LASA

cavity, electron, detector, diagnostics

1007

M. Bertucci, A. Bellandi, A. Bignami, A. Bosotti, J.F. Chen, P. Michelato, L. Monaco, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
S. Pirani
ESS, Lund, Sweden

In order to investigate the possible causes of premature thermal breakdown and performance degradation, several diagnostic techniques have been employed during the vertical tests of the Fine and Large Grain ESS Medium Beta prototypes cavities. The whole equipment, which includes second sound, fast thermometry, photodiode x ray detectors and an external NaI scintillator, is here described and the results so far obtained during the vertical tests presented.

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MOPVA063

Vertical Tests of ESS Medium Beta Prototype Cavities at LASA

cavity, vacuum, operation, accelerating-gradient

1015

A. Bosotti, A. Bellandi, M. Bertucci, A. Bignami, J.F. Chen, C.G. Maiano, P. Michelato, L. Monaco, R. Paparella, P. Pierini, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
S. Pirani
ESS, Lund, Sweden

In the framework of the INFN activity related to the European Spallation Source collaboration, the LASA infrastructure has been renewed to allow the qualification, in its vertical cryostat, of the 704 MHz medium beta cavity prototypes. A new cryogenic insert has been realized, fully equipped with dedicated mechanical supports, vacuum, thermal sensors and quench diagnostic systems. The RF test station has been upgraded as well with a new PLL electronics rack. The first beta 0.67 cavity prototype designed and produced by INFN Milano has been successfully cold tested at 2.0 K temperature, outperforming the ESS specifications. The technical features of LASA infrastructure, the design of novel components and the experimental results of cavities cold-tests are thoroughly described in this paper.

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MOPVA068

Experience on Design, Fabrication and Testing of a Large Grain ESS Medium Beta Prototype Cavity

cavity, niobium, operation, cryogenics

1027

D. Sertore, A. Bellandi, M. Bertucci, A. Bignami, A. Bosotti, J.F. Chen, C.G. Maiano, P. Michelato, L. Monaco, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
S. Pirani
ESS, Lund, Sweden

We report on the design, fabrication and testing of an ESS Medium Beta prototype cavity made with Large Grain Niobium sheets sliced from an ingot provided by CBMM. The peculiar choices during the fabrication process related to the Large Grain Niobium material are described. We present also the results of the cavity test at cryogenic temperature and the dedicated quench diagnostic.

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MOPVA078

The Window Replacement and Q Recovery of BEPCII Storage Ring SCC

cavity, vacuum, operation, positron

1046

T.M. Huang, J.P. Dai, R. Ge, S.P. Li, Z.Q. Li, H.Y. Lin, Q. Ma, W.M. Pan, Y. Sun, G.W. Wang
IHEP, Beijing, People's Republic of China
P. Sha
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

The storage ring RF system for the upgrade of the Beijing Electron Positron Collider (BEPCII) adopted two 500 MHz superconducting cavities: west for the positron ring (BPR); east for the electron ring (BER). The excessive heating of the west window was observed in Nov.2013, and not cured thoroughly*. After two years operation, the window cracked suddenly on Nov.18th, 2015. The replacement of the window was subsequently implemented in tunnel. However, the quality factor (Q) of the cavity decayed a lot after the window replacement. 90 degrees Celsius N2 gas baking of the outer surface of the cavity was carried out in situ and the Q recovered in a short time. This paper will present the process of the window replacement and the cavity Q recovery in detail.
* Tong-ming Huang et al., Chinese Physics C Vol. 40, No. 6 (2016) 067001

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MOPVA106

Experimental Studies of Asymmetric Dual Axis Cavity for Energy Recovery LINAC

cavity, electron, luminosity, linac

1105

I.V. Konoplev, A.J. Lancaster, K. Metodiev, A. Seryi
JAI, Oxford, United Kingdom
R. Ainsworth
Fermilab, Batavia, Illinois, USA
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Funding: The Leverhulme Trust via International Network Grant (IN-2015-012).
Increasing the beam charge and repetition rate leads to appearance of beam break-up instabilities in conventional ERLs. At this stage the highest current, from the SRF ERL, is around 300mA. A single turn, dual axis, compact Asymmetric Energy Recovery LINAC (AERL) was proposed. The concept assumes the use of electron beams with energies up to 300 MeV and peak currents >1A, enabling the generation of high flux EUV/X-rays and THz radiation using conventional approaches. System allows beam to be transported through each stage i.e. the acceleration, interaction and deceleration only once partially removing the feedback thus increasing the instability start current. This further improved by tuning the individual cells allowing only operating mode to be uniform inside the cavity. We present the studies of 7 cells, aluminium alloy prototype of the cavity and discuss the experimental results. We show that HOMs excited on the different axis have different R/Q factors and show the field structures of operating mode and HOMs. The experimental results observed are in good agreement with theoretical predictions and the full scale copper prototype is demonstrated.

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MOPVA117

Performance of a SRF Half-Wave-Resonator Tested at Cornell for the RAON Project

cavity, simulation, SRF, pick-up

1123

M. Ge, F. Furuta, T. Gruber, D.L. Hall, S.W. Hartman, C. Henderson, M. Liepe, S. Lok, T.I. O'Connell, P.J. Pamel, J. Sears, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
B.H. Choi, J. Joo, J.W. Kim, W.K. Kim, J. Lee, I. Shin
IBS, Daejeon, Republic of Korea

A prototype half-wave-resonator (HWR) with frequency 162.5MHz and geometrical \beta=0.12 for the RAON project is currently undergoing testing at Cornell University. Detailed vertical performance testing includes (1) test of the bare cavity without the helium tank; (2) test of the dressed cavity with helium tank. In this paper, we report on the development of the test infrastructure, test results, and performance data analysis.

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MOPVA141

Input RF Coupler Design for Energy Compensator Cavity in eRHIC

cavity, simulation, impedance, synchrotron

1184

C. Xu, S. Bellavia, I. Ben-Zvi, M. Blaskiewicz, Y. Hao, K.S. Smith, R. Than, A. Zaltsman
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.
This report gives a detail design of a 1.3 GHz input coupler for second harmonic cavity for eRHIC project. This coupler is designed to transmit 200KW CW RF to the cavity to compensate the synchrotron radiation loss. This report include RF and thermal simulation for this design.

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TUOAA3

Progress of Pr2Fe14B Based Hybrid Cryogenic Undulators at SOLEIL

undulator, cryogenics, electron, photon

1213

A.M. Ghaith, P. Berteaud, F. Blache, F. Briquez, N. Béchu, M.-E. Couprie, J. Da Silva Castro, J.M. Dubuisson, C. Herbeaux, C.A. Kitegi, A. Lestrade, O. Marcouillé, F. Marteau, M. Sebdaoui, G. Sharma, A. Somogyi, K.T. Tavakoli, M. Tilmont, M. Valléau
SOLEIL, Gif-sur-Yvette, France
C. Benabderrahmane
ESRF, Grenoble, France

Cryogenic Permanent Magnet Undulators (CPMUs) take advantage of the enhanced field performance of permanent magnets when cooled down to low temperature, enabling shorter period with sufficient magnetic field to achieve high brightness radiation in the X-ray domain. Several CPMUs have been manufactured at SOLEIL. The first CPMU of period 18 mm (U18), optimized with a phase error of 3.2° at temperature of 77 K, has been installed and operated for the past 5 years at SOLEIL for the NANOSCOPIUM beamline. We report on photon beam based alignment enabling for a better adjustment of the vertical position offset of the undulator with a precision of 50 μm, and on the correction of the taper with a precision of 5 μrad to enhance the radiation flux. A second U18 cryo-ready undulator, with a new mechanical and magnetic sorting of module shimming, has attained a phase error of 2.3° at CT without any further adjustments after the assembly. Currently, two more CPMUs are being built; a 2 m long U18 for the SOLEIL ANATOMIX beamline, and a 3 m long U15 undulator reaching a magnetic gap of 3 mm. The new challenges encountered with magnetic measurements and mechanical designs for U15 are presented.

Slides TUOAA3 [3.491 MB]

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TUOBA3

Strain and Temperature Measurements From the SNS Mercury Target Vessel During High Intensity Beam Pulses

target, simulation, data-acquisition, injection

1230

W. Blokland, Y. Liu, B.W. Riemer, M. Wendel, D.E. Winder
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. This research was supported by the DOE Office of Science, Basic Energy Science, Scientific User Facilities.
To better understand the mechanical impact of the proton beam on the lifetime on Spallation Neutron Source (SNS*) mercury-filled, stainless steel targets, these targets are now instrumented with optical and metal strain sensors, temperature sensors, and accelerometers. The strain and temperature sensors are placed inside the target vessel, between the water shroud and mercury vessel, while the accelerators are placed outside on the target mount and on the mercury return line. We now have data from four targets. The first instrumented target used regular multimode optical sensors, while later targets have used radhard multimode sensors. We are also developing super-radhard single-mode optical strain sensors to get data further into the production cycle. In this paper, we describe the data-acquisition system, compare the measured strain to the simulated strain for the different targets, estimate the survivable radiation level for each type of sensor, and discuss the implications of the results on the lifetime of the target.

Slides TUOBA3 [37.266 MB]

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TUOAB2

First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph

background, simulation, synchrotron, photon

1244

T.M. Mitsuhashi
KEK, Ibaraki, Japan
E. Bravin, F. Roncarolo, G. Trad
CERN, Geneva, Switzerland

A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.

Slides TUOAB2 [8.302 MB]

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TUOBB3

HORIZON 2020 EuPRAXIA Design Study

plasma, laser, electron, acceleration

1265

P.A. Walker, R.W. Aßmann, J. Bödewadt, R. Brinkmann, J. Dale, U. Dorda, A. Ferran Pousa, A.F. Habib, T. Heinemann, O. S. Kononenko, C. Lechner, B. Marchetti, A. Martinez de la Ossa, T.J. Mehrling, P. Niknejadi, J. Osterhoff, K. Poder, E.N. Svystun, G.E. Tauscher, M.K. Weikum, J. Zhu
DESY, Hamburg, Germany
D. Alesini, M.P. Anania, F.G. Bisesto, E. Chiadroni, M. Croia, M. Ferrario, F. Filippi, A. Gallo, A. Mostacci, R. Pompili, S. Romeo, J. Scifo, C. Vaccarezza, F. Villa
INFN/LNF, Frascati (Roma), Italy
A.S. Alexandrova, R.B. Fiorito, C.P. Welsch, J. Wolfenden
The University of Liverpool, Liverpool, United Kingdom
A.S. Alexandrova, R.B. Fiorito, C.P. Welsch, J. Wolfenden
Cockcroft Institute, Warrington, Cheshire, United Kingdom
N.E. Andreev, D. Pugacheva
JIHT RAS, Moscow, Russia
T. Audet, B. Cros, G. Maynard
CNRS LPGP Univ Paris Sud, Orsay, France
A. Bacci, D. Giove, V. Petrillo, A.R. Rossi, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
I.F. Barna, M.A. Pocsai
Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
A. Beaton, P. Delinikolas, B. Hidding, D.A. Jaroszynski, F.Y. Li, G.G. Manahan, P. Scherkl, Z.M. Sheng, M.K. Weikum
USTRAT/SUPA, Glasgow, United Kingdom
A. Beck, A. Specka
LLR, Palaiseau, France
A. Beluze, M. Mathieu, D.N. Papadopoulos
LULI, Palaiseau, France
A. Bernhard, E. Bründermann, A.-S. Müller
KIT, Karlsruhe, Germany
S. Bielawski
PhLAM/CERLA, Villeneuve d'Ascq, France
F. Brandi, G. Bussolino, L.A. Gizzi, P. Koester, B. Patrizi, G. Toci, M. Vannini
INO-CNR, Pisa, Italy
O. Bringer, A. Chancé, O. Delferrière, J. Fils, D. Garzella, P. Gastinel, X. Li, A. Mosnier, P.A.P. Nghiem, J. Schwindling, C. Simon
CEA/IRFU, Gif-sur-Yvette, France
M. Büscher, A. Lehrach
FZJ, Jülich, Germany
M. Chen, L. Yu
Shanghai Jiao Tong University, Shanghai, People's Republic of China
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
J.A. Clarke, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France
G. Dattoli, F. Nguyen
ENEA C.R. Frascati, Frascati (Roma), Italy
N. Delerue
LAL, Orsay, France
J.M. Dias, R.A. Fonseca, J.L. Martins, L.O. Silva, U. Sinha, J. Vieira
IPFN, Lisbon, Portugal
K. Ertel, M. Galimberti, R. Pattathil, D. Symes
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
J. Fils
GSI, Darmstadt, Germany
A. Giribono
INFN-Roma, Roma, Italy
L.A. Gizzi
INFN-Pisa, Pisa, Italy
F.J. Grüner, A.R. Maier
CFEL, Hamburg, Germany
F.J. Grüner, T. Heinemann, B. Hidding, O.S. Karger, A. Knetsch, A.R. Maier
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
C. Haefner
LLNL, Livermore, California, USA
B.J. Holzer
CERN, Geneva, Switzerland
S.M. Hooker
University of Oxford, Clarendon Laboratory, Oxford, United Kingdom
S.M. Hooker, R. Walczak
JAI, Oxford, United Kingdom
T. Hosokai
Osaka University, Graduate School of Engineering, Osaka, Japan
C. Joshi
UCLA, Los Angeles, California, USA
M. Kaluza
HIJ, Jena, Germany
S. Karsch
LMU, Garching, Germany
E. Khazanov, I. Kostyukov
IAP/RAS, Nizhny Novgorod, Russia
D. Khikhlukha, D. Kocon, G. Korn, A.Y. Molodozhentsev, L. Pribyl
ELI-BEAMS, Prague, Czech Republic
L. Labate, P. Tomassini
CNR/IPP, Pisa, Italy
W. Leemans, C.B. Schroeder
LBNL, Berkeley, California, USA
A. Lifschitz, V. Malka, F. Massimo
LOA, Palaiseau, France
V. Litvinenko
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA
W. Lu
TUB, Beijing, People's Republic of China
V. Malka
Ecole Polytechnique, Palaiseau, France
S. P. D. Mangles, Z. Najmudin, A. A. Sahai
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
A. Marocchino, A. Mostacci
University of Rome La Sapienza, Rome, Italy
K. Masaki, Y. Sano
JAEA/Kansai, Kyoto, Japan
U. Schramm
HZDR, Dresden, Germany
M.J.V. Streeter, A.G.R. Thomas
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
C. Szwaj
PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
C.-G. Wahlstrom
Lund Institute of Technology (LTH), Lund University, Lund, Sweden
R. Walczak
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
G.X. Xia
UMAN, Manchester, United Kingdom
M. Yabashi
JASRI/SPring-8, Hyogo, Japan
A. Zigler
The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel

The Horizon 2020 Project EuPRAXIA ('European Plasma Research Accelerator with eXcellence In Applications') aims at producing a design report of a highly compact and cost-effective European facility with multi-GeV electron beams using plasma as the acceleration medium. The accelerator facility will be based on a laser and/or a beam driven plasma acceleration approach and will be used for photon science, high-energy physics (HEP) detector tests, and other applications such as compact X-ray sources for medical imaging or material processing. EuPRAXIA started in November 2015 and will deliver the design report in October 2019. EuPRAXIA aims to be included on the ESFRI roadmap in 2020.

Slides TUOBB3 [9.269 MB]

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TUPAB003

High Energy Density Irradiation With MAMI LINAC

target, positron, electron, photon

1296

P. Heil, K. Aulenbacher, Th. Beiser
IKP, Mainz, Germany
A. Ignatenko, G.A. Moortgat-Pick, A. Ushakov
DESY, Hamburg, Germany
S. Riemann
DESY Zeuthen, Zeuthen, Germany

In order to build a positron source for the ILC, a high energy density irradiation is needed to test the used materials. At the MAMI linear accelerator such a radiation can be provided at different electron energies. With a macro pulsed source it is possible to imitate a yearlong radiation at the ILC within several hours. Small transversal beam sizes need to be provided with the focusing system and be measured at high beam currents using transition radiation and current measurements.

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TUPAB006

Achievement of Stable Pulsed Operation at 31 MV/m in the STF-2 Cryomodule for the ILC

cavity, cryomodule, operation, accelerating-gradient

1308

Y. Yamamoto, T. Dohmae, M. Egi, K. Hara, T. Honma, E. Kako, Y. Kojima, T. Konomi, N. Kota, T. Kubo, T. Matsumoto, T. Miura, H. Nakai, K. Nakanishi, G.-T. Park, T. Saeki, H. Shimizu, T. Shishido, T. Takenaka, K. Umemori
KEK, Ibaraki, Japan

In the Superconducting RF Test Facility (STF) in KEK, the cooldown test for the STF-2 cryomodule with 12 cavities has been done totally three times since 2014. In 2016, the 3rd cooldown test for the STF-2 cryomodule including the capture cryomodule with 2 cavities, which was used for Quantum Beam Project in 2012, was successfully done. The main purpose is the vector-sum operation with 8 cavities at average accelerating gradient of 31 MV/m as the ILC specification, and the others are the measurement for Lorenz Force Detuning (LFD) and unloaded Q value, and Low Level RF (LLRF) study, etc. During 8 cavities operation, piezo actuators were used for the compensation of LFD, and the feed-forward and vector-sum control system by LLRF worked perfectly for keeping the lowest forward power and the stable flat-top of accelerating gradient. In this paper, the result for the STF-2 cryomodule in the 3rd cooldown test will be presented in detail.

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TUPAB007

Analysis of the Dependability of the LHC Quench Detection System During LHC Run 2 and Further System Evolution

operation, software, electronics, superconducting-magnet

1311

T. Podzorny, D.O. Calcoen, R. Denz, A.P. Siemko, J. Spasic, J. Steckert
CERN, Geneva, Switzerland

The quench detection system (QDS) of the LHC superconducting circuits is an essential part of the LHC machine protection and ensures the integrity of key elements of the accelerator. The large amount of hardwired and software interlock channels of the QDS requires a very high system dependability in order to reduce the risk of affecting the successful operation of the LHC. This contribution will present methods and tools for systematic fault tracking and analysis, and will discuss recent results obtained during the LHC production run in 2016. Measures for maintaining and further improving of the system performance will be explained. An overview of the further evolution of the LHC QDS also in view of the upcoming High Luminosity Upgrade of the LHC will be given.

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TUPAB020

AREAL 50 MeV Electron Accelerator Project for THz and Middle IR FEL

electron, emittance, gun, FEL

1355

G.A. Amatuni, Z.G. Amirkhanyan, V.S. Avagyan, A. Azatyan, V. Danielyan, H. Davtyan, S.G. Dekhtiarov, N. Ghazaryan, B. Grigoryan, L. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, T. Markosyan, N. Martirosyan, Sh.A. Mehrabyan, T. Melkumyan, T.H. Mkrtchyan, V.H. Petrosyan, V. Sahakyan, A. Sargsyan, A.S. Simonyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, Ta.S. Vardanyan, T.L. Vardanyan, V. V. Vardanyan, A.S. Yeremyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
P.S. Manukyan
SEUA, Yerevan, Armenia
A.V. Tsakanian
HZB, Berlin, Germany

Advanced Research Electron Accelerator Laboratory (AREAL) is an electron accelerator project based on photo cathode RF gun. First phase of the facility is a 5 MeV energy RF photogun, which is currently under operation. The facility development implies energy upgrade to 50 MeV with further delivery of the electron beam to the undulator sections for Free Electron Laser and coherent undulator radiation generation in MIR and THz frequency ranges respectively. In this report the design study of AREAL 50 MeV facility main systems along with the beam dynamics and characteristics of expected radiation are presented.

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TUPAB036

Training and Characterization of 1.5m Long Conduction Cooled Superconducting Undulator Coils with 20 mm Period Length

undulator, synchrotron, vacuum, storage-ring

1399

A.W. Grau, S. Casalbuoni, N. Glamann, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany
C. Boffo, T.A. Gerhard, M. Turenne, W. Walter
Babcock Noell GmbH, Wuerzburg, Germany

The Institute for Beam Physics and Technology (IBPT) of the Karlsruhe Institute of Technology (KIT), and the company Babcock Noell GmbH (BNG) are running an R&D program on superconducting undulators (SCUs). The collaboration is working on a SCU with 20 mm period length (SCU20) for ANKA, the test facility and synchrotron radiation source, run by the IBPT. The 1.5 m long undulator coils have been tested in a conduction-cooled environment. This contribution describes the training, the stability and the thermal behavior of the coils.

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TUPAB049

Development of the High Power Terahertz Light Sources at LEBRA Linac in Nihon University

target, electron, FEL, linac

1437

T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Tanaka
LEBRA, Funabashi, Japan
H. Ogawa, N. Sei
AIST, Tsukuba, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539.
Development of a THz light source has been underway at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University in collaboration with National Institute of Advanced Industrial Science and Technology (AIST) since 2011. Basic research on coherent transition radiation (CTR) in the THz region has been carried out using the Parametric X-ray Radiation (PXR)-beam line of LEBRA. Since fiscal year 2016, the THz transport line has been constructed on the same axis as the PXR beam line taking the construction cost and simultaneous use of the two beams into account. Basic measurement and intensity upgrading test have been carried out for the THz lights generated on the PXR-generating electron beam line. The average intensity of the THz lights obtained at the output port in the accelerator room has been 5 mW. Construction of the THz transport beam line and the property of the THz lights is discussed in the report.

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TUPAB068

Design of the CPMU Vacuum System at the HEPS

vacuum, undulator, cryogenics, photon

1482

L. Zhang, H.H. Lu, S.C. Sun
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a 3rd generation synchrotron radiation light source. Its beam energy is 6 GeV and its emittance is less than 60 pm'rad, which can provide high brilliance hard X-rays to several tens of experimental stations. The Cryogenic Permanent Magnet Undulator (CPMU) is one of the key components to achieve the high brilliance. And its vacuum system is necessary to provide an ultra-high vacuum environment for CPMU operation. To design the CPMU vacuum system, we do experiments to test the outgassing rate, estimate the total gas load, calculate the effective pumping speed, design the baking program and select all pumps and other vacuum equipments. This paper presents the design specifications and the assemblage status of the CPMU vacuum system.

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TUPAB071

Experimental Results on THz Superradiation From the Undulator in Tsinghua University Beamline

undulator, electron, detector, experiment

1488

X.L. Su, Y.-C. Du, W.-H. Huang, L. Niu, C.-X. Tang, Q.L. Tian, D. Wang, L.X. Yan
TUB, Beijing, People's Republic of China
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

In this paper, the first operation of a widely tunable 8-period undulator at terahertz (THz) frequency in Tsinghua University beamline was reported. Superradiate undulator radiation from sub-picosecond electron bunches compressed by chicane was observed. The measured radiation curve shows clearly that the radiation energy is proportional to the charge square, and the THz frequency can be changed from 0.4 THz to 10 THz with narrow-band spectrums. Our results demonstrate a high power and tunable coherent THz source, which could be useful for many applications in the future.

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TUPAB077

A Combined THz/X-ray Source Based on Brake-applied Velocity Bunching and Magnetic Compression

electron, bunching, emittance, laser

1500

R. Huang, Z.G. He, Q.K. Jia, B. Li, W.W. Li, L. Wang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by Chinese Universities Scientific Fund under Contracts WK2310000063 and WK2310000047
Ultrashort electron beam can be realized by the process of velocity bunching and magnetic compression. Velocity bunching technique is able to compress the bunch at relatively low energy, which presents peculiar challenges when approaching a very high current and a low transverse emittance in photoinjectors. A brake-applied velocity bunching scheme was proposed, so that the transverse emittance of the beam could be almost compensated even if the compression factor was extremely high. By adding a magnetic compressor, one could obtain a shorter beam and achieve the coherent synchrotron radiation in THz range. Meanwhile, when making the final compressed beam collide with the laser, one could acquire high energy X-ray pulses. This opens the possibility for some interesting combinations of pump-and-probe experiments.

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TUPAB087

Undulator Commissioning Experience at PAL-XFEL

undulator, electron, background, site

1520

D.E. Kim, Y.G. Jung, H.-S. Kang, I.S. Ko, H.-G. Lee, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea
I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea
J. Pflüger
XFEL. EU, Hamburg, Germany

Pohang Accelerator Laboratory (PAL) is developing a 0.1 nm SASE based FEL based on 10 GeV S-band linear accelerator named PAL-XFEL. The hard X-ray undulator line requires 20 units of 5 m long hybrid-type conventional planar undulator while soft X-ray line requires 7 units of 5 m long hybrid type planar undulators. In this report, the final measurement results of all the undulators, phase matching scheme, and the commissioning experiences will be summarized.

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TUPAB104

Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators

polarization, photon, optics, undulator

1556

T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang
NSRRC, Hsinchu, Taiwan
H.W. Luo
NTHU, Hsinchu, Taiwan

While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.

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TUPAB106

Development of a Cryogenic Permanent Magnet Undulator for the TPS

undulator, vacuum, permanent-magnet, cryogenics

1562

J.C. Huang, C.H. Chang, T.Y. Chung, C.-S. Hwang, J.C. Jan, C.S. Yang, C.K. Yang
NSRRC, Hsinchu, Taiwan
H. Kitamura
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

Development of a cryogenic permanent magnet undu-lator (CPMU) at the Taiwan Photon Source (TPS) is the most recent activity toward a new light source for the Phase-II beamlines. A hybrid-type CPMU with a period length of 15 mm is under construction with PrFeB permanent-magnet materials. A maximum effective magnetic field of 1.77 T at a gap of 3 mm is expected when the magnets (PMs) are cooled down around 77 K. The features desired for the TPS CPMU are low-intrinsic-phase-error characteristics and high thermal budget for various kinds of heat loads. The design of the TPS CPMU is discussed in this paper.

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TUPAB134

Life Expectancy Studies for LCLS-II Permanent Magnet Undulators

undulator, permanent-magnet, electron, optics

1640

M. Santana-Leitner, D.E. Bruch, R.C. Field, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, M. Rowen, S.W. Score
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy contract DE-AC02-76SF00515
LCLSII at SLAC National Accelerator Laboratory will add a 4 GeV superconducting Linac to the existing 20 GeV Cu structure. Electron beams from the two sources going through two new variable gap undulators [*] will produce FEL ranging 200-5000 keV at up to 929 kHz, also reaching 20 keV at low frequency. Such performance will be achieved by hybrid design undulators with NdFeB magnet blocks until radiation-induced demagnetization exceeds 0.01%. This is a sizable challenge, as LCLS-II will carry 120 kW beams in both its soft (SXR) and hard (HXR) beam-lines. Even small fractional losses could result excessive if too frequent or not detected and aborted fast enough. A model of SXR undulator was set for FLUKA [**] radiation transport, including segments, phase-shifters, quadrupoles, RFBPM, stands/pillars and interconnecting parts. Components were installed according to MAD files, which were also used to code the optics. Beam-loss/shower propagation was simulated for beam mis-steering, interception at wire scanners and gas-bremsstrahlung interactions. Results help set limits on shut-off times, uniform loss levels and wire scanner use, and to define placement for beam loss monitors.
* M. Leitner et al, Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project, these proceedings
** A. Ferrari et al, The FLUKA Code: Developments and Challenges for High Energy and Medical Applications, Nuclear Data Sheets 120, 211-214 (2014)

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TUPAB140

Analysis and Correction of in-Vacuum Undulator Misalignment Effects in a Storage Ring Synchrotron Radiation Source

undulator, electron, alignment, storage-ring

1663

O.V. Chubar, T.A. Caswell, Y. Chen-Wiegart, A. Fluerasu, Y. Hidaka, D.A. Hidas, C.A. Kitegi, M.S. Rakitin, T. Tanabe, J. Thieme, L. Wiegart, G. Williams
BNL, Upton, Long Island, New York, USA

Funding: Work was partially supported by US DOE SBIR grants DE-SC0006284 and DE-SC0011237.
In-vacuum undulators (IVU) are currently very extensively used at different light source facilities, and in particular in medium-energy storage rings, for the production of high-brightness and high-flux hard X-rays. The relatively small (~5 mm or less) vertical magnetic gaps used in these planar undulators make them, however, rather sensitive to the accuracy of alignment of magnet arrays with respect to electron orbit in the vertical plane. Based on results of commissioning of a number of IVUs at hard X-ray beamlines of NSLS-II, their eventual misalignment with respect to the electron orbit was found to be among frequent reasons of spectral underperformance of the beamlines. We will present results of simulations of different IVU misalignment effects on magnetic fields seen by electron beam and on the emitted undulator radiation spectra. The simulations show e.g. that an impact of angular misalignment of an IVU on the radiation spectrum can be minimized if the IVU elevation is selected to make the electron orbit to pass through the IVU magnetic center. Experimental results of spectrum-based alignment of IVUs at hard X-ray beamlines will be presented.

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TUPIK043

Upgrade of the Neutron Dose Measurement System at BESSY

neutron, injection, electron, synchrotron

1781

K. Ott, Y. Bergmann, M. Martin, L. Pichl
HZB, Berlin, Germany

Funding: Funded by the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie and by the Land Berlin
Neutron radiation fields at synchrotron light sources are caused by bremsstrahlung from electron losses in accelerator components. Inside the enclosure and in transversal direction neutron and gamma radiation is of the same order of magnitude but high energy neutrons are much more penetrating. This causes outside the shielding neutron spectra with two broad maxima at about 1 MeV and 100 MeV. Standard Anderson-Braun or Leake neutron monitors measure thermalized neutrons in a proportional counter tube by nuclear reactions which limits the measurement range to neutron energies < 10 MeV. This implies two considerable systematic errors: Pulsed neutron beams causes dead-time losses due to the time structure of injections and the moderators are not sufficient to moderate high energy neutrons down to thermal energies. We determined and fixed these measurement errors by faster preamplifiers and by a more effective moderator developed by us, which expands the measurement range up to several GeV. Examples of the application at BESSY are presented.

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TUPIK055

Target Investigation Driven by a 10 MeV Electron Linac for Bremsstrahlung Production

target, electron, linac, photon

1819

M. Yarmohammadi Satri, M. Lamehi, H. Shaker
IPM, Tehran, Iran
F. Ghasemi
NSTRI, Tehran, Iran

IPM E-Linac is a 10 MeV electron linear accelerator presently under construction at Institute for Research in Fundamental Sciences (IPM). It will accelerate electron from 45 keV to 10 MeV along the 160 cm accelerating tube. One of the beam energy measurement devices is designed based on the production of bremsstrahlung radiation. Target of the electron linac presents a key role in the production of bremsstrahlung. In this paper, we present the simulation results for an investigation on the bremsstrahlung radiation production based on target thickness, radius and atomic number, Z. We have applied Fluka Monte Carlo code for collecting the dose equiva-lent of generated bremsstrahlung along the target central axis at 30cm located downstream the target.

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TUPIK071

The Novel Implementation of the Orbit Correction Algorithm for Solaris Storage Ring

TANGO, storage-ring, controls, synchrotron

1861

P. Sagało, L.J. Dudek, A. Kisiel, G.W. Kowalski, A.I. Wawrzyniak
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
P.P. Goryl
3controls, Kraków, Poland

The storage ring which is located in the National Synchrotron Radiation Center SOLARIS works under the TANGO control system. So far the correction of an electron beam orbit has been performed with an algorithm implemented in the Matlab Middle Layer (MML). To ensure consistency of the correction process with the entire control system, a new implementation of this algorithm has been developed. The algorithm of orbit correction based on SVD has been implemented as a TANGO Device, which is one of the fundamental blocks used in the Tango control system. The entire code has been written in the Python.

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TUPIK080

Accelerator Personnel Safety Systems for European Spallation Source

PLC, proton, linac, controls

1884

M. Mansouri, S.L. Birch, A. Nordt, D. Paulic, Y.K. Sin, A. Toral Diez
ESS, Lund, Sweden

The European Spallation Source (ESS) is a collabora-tion of 17 European countries to build the world's most powerful neutron source for research. ESS is under con-struction since 2014 and it will produce first neutrons in 2019. The linear proton accelerator is composed of nor-mal conducting sections plus the superconducting linac. When operational, such facilities include various hazards, such as ionizing radiation, high voltage and oxygen defi-ciency. The accelerator Personal Safety System (PSS) limits exposure to them and ensures personnel safety in the accelerator tunnel. It will be developed in accordance with IEC 61508 standard (Functional Safety of Electri-cal/Electronic/Programmable Electronic Safety-related Systems), which has become a good practice in similar facilities to develop safety related systems. This paper gives an overview of the accelerator PSS and its subsys-tems. The progress of the accelerator PSS design and the selected software and hardware technologies will also be described.

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TUPIK084

The EPICS Based Control System at the FREIA Laboratory

EPICS, controls, PLC, interface

1890

K. Fransson, K.J. Gajewski, M. Jacewicz, M. Jobs, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

FREIA (Facility for REsearch and Instrumentation for Accelerator development) Laboratory at Uppsala University, Sweden, is a new facility, inaugurated 2013. Initially FREIA is testing and developing superconducting accelerating cavities and high power RF sources in collaboration with the European Spallation Source (ESS). Later projects include testing of superconducting cavities and magnets for the high luminosity LHC. The high level control, alarm system and archiving is implemented in EPICS. Presently this includes a helium liquefaction plant, a horizontal test cryostat, two high power RF amplifiers, a low level RF system, environment monitoring and safety systems. Some attention will be given to integration of commercially acquired systems as well as the safety system, interlocks and radiation monitoring. The implementation of the EPICS environment follows closely that of ESS and thus can provide a test bench for developments at ESS.

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TUPIK101

Development and Construction of Safety and Control Systems for the TPS Front End Interlock

controls, vacuum, photon, status

1947

J. -Y. Chuang, C.K. Chan, Y.M. Hsiao, C.K. Kuan, Y.Z. Lin, I.C. Sheng, Y.C. Yang
NSRRC, Hsinchu, Taiwan
C.S. Lin
NPUST, Pingtung, Taiwan

The Taiwan photon source (TPS) at NSRRC (National Taiwan Photon Source) is a 3rd generation, 3 GeV storage ring with designed current of 500 mA. In phase-I, six insertion device beamlines have been available to users after the safety interlock systems were commissioned and reviewed. National Instrument (NI) compact RIO 9030 is used for the front end interlock control system, and both scan and FPGA modes are activated in a hybrid mode to enhance the safety reliability. The personnel and machine protection system as well as EPICS communications of the TPS control system are presented in this paper as well.

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TUPIK106

Analysis of the Synchrotron Radiation from Segmented Undulator in Double-Mini Beta Function

undulator, brilliance, electron, photon

1964

H.W. Luo, C.H. Lee
NTHU, Hsinchu, Taiwan
T.Y. Chung, C.-S. Hwang
NSRRC, Hsinchu, Taiwan
C.-S. Hwang
NCTU, Hsinchu, Taiwan

Three long straight sections with double-mini beta-y lattice were created in the Taiwan Photon Source (TPS) for which the effects of focusing elements and phase shifters between the collinear undulators result in incorrect calculations of the brilliance while assuming a Gaussian-approximation. Therefore, an on-axis Wigner distribution function (WDF), which includes effects of wave phenomena, is a natural way to measure the intensity of synchrotron radiation and is used in this article as the definition of brilliance.

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TUPVA004

Synchrotron Radiation Backgrounds for the FCC-hh Experiments

photon, simulation, optics, collider

2031

F. Collamati
INFN-Roma1, Rome, Italy
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
H. Burkhardt, R. Kersevan
CERN, Geneva, Switzerland

Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305.
We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.

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TUPVA006

Lessons Learnt from the 2016 LHC Run and Prospects for HL-LHC Availability

luminosity, proton, target, operation

2039

A. Apollonio, O. Rey Orozko, R. Schmidt, M. Valette, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland

The LHC exhibited unprecedented availability during the 2016 proton run, producing about 40 fb-1 of integrated luminosity, surpassing the sum of production during the 4 previous years. This was achieved while running steadily with a peak luminosity above the design target of 1034 cm- 2s⁻¹. Individual system performance and an increased experience operating the LHC were fundamental for these achievements, following the consolidations and improvements deployed during the Long Shutdown 1 and the Year End Technical Stop in 2015. The implications of this excellent performance in the context of the High Luminosity LHC are discussed in this paper, with the goal of defining the possible integrated luminosity reach of HL-LHC when considering the different operating conditions and the newly developed systems and technologies.

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TUPVA008

Assessment of Thermal Loads in the CERN SPS Crab Cavities Cryomodule

cavity, cryomodule, HOM, pick-up

2047

F. Carra, J. Apeland, R. Calaga, O. Capatina, T. Capelli, C. Zanoni
CERN, Geneva, Switzerland
S. Verdú-Andrés
BNL, Upton, Long Island, New York, USA

Funding: *Work supported by the European Union HL-LHC Project and by US DOE through Brookhaven Science Associates LLC under contract No. DE-AC02-98CH10886 and the US LHC Accelerator Research Program (LARP). Research supported by the HL-LHC project.
As a part of the HL-LHC upgrade, a cryomodule is designed to host two crab cavities for a first test with protons in the SPS machine. The evaluation of the cryomodule heat loads is essential to dimension the cryogenic infrastructure of the system. The current design features two cryogenic circuits. The first circuit adopts superfluid helium at 2 K to maintain the cavities in the superconducting state. The second circuit, based on helium gas at a temperature between 50 K and 70 K, is connected to the thermal screen, also serving as heat intercept for all the interfaces between the cold mass and the external environment. An overview of the heat loads to both circuits, and the combined numerical and analytical estimations, is presented. The heat load of each element is detailed for the static and dynamic scenarios, with considerations on the design choices for the thermal optimization of the most critical components.
#Federico.carra@cern.ch

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TUPVA011

Comparing Behaviour of Simulated Proton Synchrotron Radiation in the Arcs of the LHC with Measurements

photon, simulation, synchrotron, synchrotron-radiation

2059

G. Guillermo Cantón, M. Ady, R. Kersevan, F. Zimmermann
CERN, Geneva, Switzerland
M. Angelucci, R. Cimino, E. La Francesca
INFN/LNF, Frascati (Roma), Italy
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: EuCARD2 CONACyT
In previous work it was shown that at high proton-beam energies, synchrotron radiation is an important source of beam-screen heating, of beam-related vacuum pressure increase, and of primary photoelectrons, which can contribute to electron cloud formation. We have used the Synrad3D code developed at Cornell to simulate the photon distributions in the arcs of the LHC, HL-LHC, and FCC-hh. Specifically, for the LHC we studied the effect of the sawtooth chamber. In this paper specific results of the Synrad3D simulations are compared with simulations in Synrad+, developed at CERN; and later on compared with experimental data for actual LHC vacuum-chamber samples.

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TUPVA015

Radiation Levels at the LHC: 2012, 2015 and 2016 Proton Physics Operations in View of HL-LHC requirements

luminosity, operation, proton, insertion

2075

C. Martinella, M. Brugger, S. Danzeca, R. Garcia Alia, Y. Kadi, O. Stein, C. Xu
CERN, Geneva, Switzerland

The variety of beam losses produced in the Large Hadron Collider (LHC) creates a mixed and complex radiation field. During 2012, 2015 and 2016, Beam Loss Monitors and RadMons were used to monitor the inte-grated dose and the High Energy Hadrons fluence in order to anticipate the electronics degradation and inves-tigate the cause of failures. The annual radiation levels are compared; highlighting the mechanisms in the pro-duction of beam losses and the impact of the different squeeze and crossing angle. In addition, the increase of beam-gas interaction is discussed comparing operations at 25 ns and 50 ns bunch spacing. A strategy is presented to allow for a continuous respective evaluation during the upcoming LHC and future High Luminosity LHC (HL-LHC) operations.

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TUPVA016

Identification and Analysis of Prompt Dose Maxima in the Insertion Regions IR1 and IR5 of the Large Hadron Collider

luminosity, operation, dipole, quadrupole

2078

O. Stein, M. Brugger, S. Danzeca, R. Garcia Alia, Y. Kadi, M. Kastriotou, C. Martinella, C. Xu
CERN, Geneva, Switzerland

During the operation of the LHC the continuous particle losses create a radiation field in the LHC tunnel and the adjacent caverns. Exposed electronics and accelerator components show dose dependent accelerated aging effects and stochastic Single Event Effects which can lead to faults and downtime of the LHC. In order to achieve an optimal life duration, the position of the equipment is chosen in dependency of the amplitude of the radiation fields. Therefore, it is crucial to monitor the prompt dose distributions along the whole LHC. By using the LHC beam loss monitor and RadMon systems, the prompt dose during the accelerator operation is continuously monitored. Measurements in the long straight sections and the dispersion suppressors in IR1 (ATLAS) and in IR5 (CMS) have shown that the radiation levels have localised maxima which exceed the base line by 1 to 2 orders of magnitude. The analysis of these radiation peaks will be presented and the underlying loss mechanisms will be discussed. The results will help to identify areas not suitable for radiation sensitive electronics. Implications on the expected radiation levels for High-Luminosity LHC are also discussed.

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TUPVA021

Impact of Collision Debris in the HL-LHC ATLAS and CMS Insertions

luminosity, proton, optics, insertion

2093

A. Tsinganis, F. Cerutti
CERN, Geneva, Switzerland

The High Luminosity upgrade of the LHC (HL-LHC) foresees the baseline operation of the accelerator at a 5 times higher peak luminosity (5.0x1034cm^-2s⁻¹). The impact of collision debris on the magnets and other equipment in the triplet region and matching section of the ATLAS and CMS insertions has been evaluated by means of detailed FLUKA models implementing the latest optics and layout version. Qualitative and quantitative differences between the vertical and horizontal beam crossing schemes are highlighted. With measures in place to mitigate the effects of the interruption of the beam screen in the triplet interconnections and the Q4 aperture reduction, peak dose values in the superconducting coils remain below 30MGy in the triplet-D1 and below 12MGy in the matching section magnets for an integrated luminosity of 3000fb-1. Peak power density values are lower than 3mW/cm³ and 1mW/cm³ in the triplet and matching section respectively. Total heat loads in magnets, collimators, masks and absorbers were also estimated, along with dose and particle fluence maps relevant for Radiation to Electronics (R2E) aspects. The effect of a displacement of the interaction point is also addressed.

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TUPVA041

Exploring the Triplet Parameter Space to Optimise the Final Focus of the FCC-hh

optics, quadrupole, shielding, target

2155

L. van Riesen-Haupt, J.L. Abelleira, E. Cruz Alaniz, A. Seryi
JAI, Oxford, United Kingdom

One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation and MADX for more precise calculations. In cooperation with radiation studies, this algorithm was then applied to design an alternative triplet for the final focus of the Future Circular Collider.

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TUPVA044

Modelling and Measurements of Bunch Profiles at the LHC

emittance, synchrotron, luminosity, scattering

2167

S. Papadopoulou, F. Antoniou, T. Argyropoulos, M. Hostettler, Y. Papaphilippou
CERN, Geneva, Switzerland
M. Fitterer
Fermilab, Batavia, Illinois, USA

The bunch profiles in the LHC are often observed to be non-Gaussian, both at Flat Bottom (FB) and Flat Top (FT) energies. Especially at FT, an evolution of the tail population in time is observed. In this respect, the Monte-Carlo Software for IBS and Radiation effects (SIRE) is used to track different types of beam distributions. The impact of the distribution shape on the evolution of bunch characteristics is studied. The results are compared with observations from the LHC Run 2 data.

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TUPVA048

Calculation of Particle Loss Maps for 2016 RHIC Gold-Gold Run

simulation, detector, operation, kicker

2181

Y. Luo, K.A. Drees, W. Fischer, X. Gu, A. Marusic, G. Robert-Demolaize, 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.
In the 2016 RHIC 100~GeV gold-gold (Au-Au) run, 20~mm orbit bumps were installed in the arcs to protect the experimental detectors from abort kicker prefiring. Chronic particle losses were observed in the arcs with these orbit bumps. Those particle losses are mainly from the 78+Au197 and 79+Au196 particles generated from bound-free pair production (BFPP) and electromagnetic dissociation (EMD) associated with the Au-Au collision at the IPs. In this article, we present simulated particle losses of 78+Au197 and 79+Au196 and calculate the particle loss distribution in the ring. The calculated particle loss maps are compared with operational observations.

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TUPVA114

Nuclotron New Beam Channels for Applied Researches

ion, target, heavy-ion, ion-source

2355

E. Syresin, A.V. Butenko, O.S. Kozlov, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
A.V. Bakhmutova, A.V. Bogdanov, R. Gavrilin, A. Golubev, A.V. Kantsyrev, D.A. Liakin, N.V. Markov, V.A. Panyushkin, V. Skachkov, S.A. Visotski
ITEP, Moscow, Russia

Three new experimental areas are organized for applied physics researches in frame of realization of the accelerator facility NICA. New beamlines are under development for applied researches on Nuclotron accelerator. The ion beams with energy of 250-800 MeV/n extracted from Nuclotron will be used for the radio-biological and materials research and modeling of the cosmic rays interactions with microchips. The equipment of two experimental stations is designed by JINR-ITEP collaboration for these applied researches. The design of the magnetic system, the beam diagnostic equipment, the target stations are developed in frame of this project. The design and construction of these beamlines and experimental stations are planned in 2017-2020. Low ion energy station will be installed in 2021-2023 inside the transportation channel from heavy ion linac HILAC. Two new stations for applied researches will be constructed in 2021-2023 with ion beams at energy up 4.5 GeV/u.

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TUPVA153

Accelerator-Based Education Activities at JINR

vacuum, controls, electron, linac

2455

M.A. Nozdrin, D. Belozerov, K. Gikal, V. Kobets, S. Pakuliak, V. Shabratov, G. Shirkov, D. Shvidkiy, K. Verlamov, A. Zhemchugov, D. Zlydenny
JINR, Dubna, Moscow Region, Russia

Professional practice is essential to train an engineer. However, many activities are impossible to run at high school, especially if they require sophisticated equipment such as accelerators. A series of practical engineering courses is being set up at the Joint Institute for Nuclear Research to overcome these difficulties while educating students from the JINR Member States. A dedicated 'training' beamline of the Linac-200 electron accelerator is being constructed to practice the beam management and diagnostics, including the operation of standard beamline elements such as a bending dipole, quadrupoles, a sextupole and steerers. Various types of particle detectors can be used in the beam area as well in order to study the passage of electrons and photons through matter and to learn about the detector operation and properties. The practice at the beam will be accompanied by a series of hands-on trainings on radiation protection, vacuum and RF technology, electronics and metrology.

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WEOCA2

Experience of Taiwan Photon Source Commissioning and Operation

vacuum, operation, injection, booster

2495

Y.-C. Liu, C.H. Chen, J.Y. Chen, M.-S. Chiu, P.J. Chou, S. Fann, C.S. Huang, C.-C. Kuo, T.Y. Lee, C.C. Liang, G.-H. Luo, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The TPS commissioning period is from August 2014 to March 2016. The experience of phase I [1] (bare lattice 2014.8~2015.3) and phase II [2,3] (SRF and insertion devices 2015.9~2016.3) commissioning is overviewed. Taiwan Photon Source (TPS) started user operation in March 2016. The delivery user time reached 3211 hours. The continuous improvements of integrated accelerator performance are described and future developments are discussed.

Slides WEOCA2 [32.368 MB]

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WEOCB3

The Radiation Damage in Accelerator Target Environments (RaDIATE) Collaboration R&D Program - Status and Future Activities

target, proton, experiment, status

2550

P. Hurh
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments), founded in 2012, has grown to over 50 participants and 14 institutions globally. The primary objective is to harness existing expertise in nuclear materials and accelerator targets to generate new and useful materials data for application within the accelerator and fission/fusion communities. Current activities include post-irradiation examination of materials taken from existing beamlines (such as the NuMI beryllium primary beam window and graphite target fins from Fermilab) as well as new irradiations of candidate target materials at low energy and high energy beam facilities (such as titanium and aluminum alloys, glassy carbon, TZM and tungsten). In addition, the program includes thermal shock experiments utilizing high intensity proton beam pulses available at the HiRadMat facility at CERN. Status of current RaDIATE activities as well as future plans will be discussed, including highlights of preliminary results from various ongoing RaDIATE activities and the high level plan to explore the high-power accelerator target relevant thermal shock and radiation damage parameter space.

Slides WEOCB3 [10.635 MB]

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WEPAB001

Parallel Operation of SASE1 and SASE3 Undulator Sections of European XFEL

undulator, simulation, kicker, operation

2554

A. Sargsyan, V. Sahakyan
CANDLE SRI, Yerevan, Armenia
W. Decking
DESY, Hamburg, Germany

In the current paper the numerical simulation results for parallel (decoupled) operation of SASE1 and SASE3 undulator sections of European XFEL are presented. The study was based on the idea of betatron switcher imple-mentation. It was shown that it is possible to avoid energy spread growth in SASE1 and to reach the saturation in SASE3 in desirable range of radiation wavelengths by a trajectory kick before SASE1 and its correction before SASE3.

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WEPAB007

Pseudo Single Bunch Qualities Added to Short Pulse Operation of BESSY II

experiment, synchrotron, timing, operation

2574

R. Müller, T. Birke, F. Falkenstern, K. Holldack, A. Jankowiak, M. Ries, A. Schälicke
HZB, Berlin, Germany

Funding: Work supported by the German Bundesministerium für Bildung und Forschung, Land Berlin and grants of Helmholtz Association
BESSY II features sophisticated filling patterns as well as manipulation and separation techniques of custom bunches to serve both timing and photon hungry experiments at the same time*. Recently, the low alpha operation mode, providing bunch lengths as short as 2 ps, was extended by pseudo single bunch options. A robust technique to excite one bunch with constant displacement and enlargement was implemented for pulse picking by resonant excitation (PPRE)** users. In addition, reliable scraping of an isolated bunch to provide zero current bunch length is opening new timing opportunities. The simultaneous usage of different photon characteristics: high intensity CSR, non-bursting CSR, short duration as well as operation mode specific X-rays impose new challenges. Sensitive tune measurements and feedback mechanisms had to be developed for all three dimensions. Negative alpha is in consideration to overcome the top up efficiency constraints.
*R. Müller et.al. BESSY II Supports an Extensive Suite of Timing Experiments, IPAC16
**K. Holldack et.al. Single bunch X-ray pulses on demand from a multi-bunch SR source, Nature Comm.5, 2014

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WEPAB009

Pilot Experiments and New Developments at the DELTA Short-Pulse Facility

laser, electron, undulator, experiment

2578

S. Khan, B. Büsing, F. Götz, M.A. Jebramcik, N.M. Lockmann, C. Mai, A. Meyer auf der Heide, R. Niemczyk, B. Riemann, G. Shayeganrad, M. Suski, P. Ungelenk, D. Zimmermann
DELTA, Dortmund, Germany
U. Bovensiepen, S. Döring, A. Eschenlohr, M. Ligges, L. Plucinski, M. Plötzing, C.M. Schneider, S. Xiao
Universität Duisburg-Essen, Duisburg, Germany
S. Cramm
Forschungszentrum Jülich, Peter-Gruenberg-Institut-6, Jülich, Germany
M. Gehlmann
Forschungszentrum Jülich, Peter Gruenberg Institut, Jülich, Germany

Funding: BMBF 05K16PEA, BMBF 05K16PEB, Mercur Pr-2014-0047
At the 1.5-GeV synchrotron light source DELTA operated by the TU Dortmund University, ultrashort radiation pulses in the vacuum ultraviolet (VUV) and terahertz (THz) regime are routinely generated by the interaction of electron bunches with femtosecond laser pulses. A laser-induced energy modulation is converted into a density modulation (microbunching) by a magnetic chicane, leading to coherent emission at harmonics of the initial laser wavelength (coherent harmonic generation, CHG). Path length differences of the energy-modulated electrons along the magnetic lattice lead to a dip in the longitudinal charge distribution, which gives rise to the coherent emission of THz radiation. In first pump-probe photoemission experiments, the spatial and temporal overlap of laser pump and CHG probe pulse on the sample was demonstrated. Furthermore, the effect of two temporally separated seed pulses was studied in the VUV and (sub-)THz regime.

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WEPAB010

Progress Towards an EEHG-Based Short-Pulse Source at DELTA

electron, laser, undulator, synchrotron

2582

A. Meyer auf der Heide, F.H. Bahnsen, B. Büsing, F. Götz, S. Hilbrich, M.A. Jebramcik, S. Khan, N.M. Lockmann, C. Mai, R. Niemczyk, B. Riemann, G. Shayeganrad, M. Suski, P. Ungelenk, D. Zimmermann
DELTA, Dortmund, Germany

Funding: Work supported by the accelerator initiative (ARD) of the Helmholtz society, BMBF 05K13PE3, BMBF 05K16PEA.
The short-pulse source at the 1.5-GeV synchrotron light source DELTA, operated by the TU Dortmund University, enables the generation of sub-ps radiation pulses in the VUV regime based on coherent harmonic generation (CHG). As an upgrade, the employment of echo-enabled harmonic generation (EEHG) is planned which allows to produce shorter wavelengths. Recent developments and measurements regarding the twofold energy modulation required for EEHG are presented.

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WEPAB016

Experience in Operating sFLASH With High-Gain Harmonic Generation

FEL, laser, electron, photon

2596

J. Bödewadt, R.W. Aßmann, N. Ekanayake, B. Faatz, I. Hartl, T. Laarmann, C. Lechner, M.M. Mohammad Kazemi, A. Przystawik
DESY, Hamburg, Germany
Ph. Amstutz, A. Azima, M. Drescher, W. Hillert, L.L. Lazzarino, Th. Maltezopoulos, V. Miltchev, T. Plath, J. Roßbach
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
K.E. Hacker, S. Khan, N.M. Lockmann, R. Molo
DELTA, Dortmund, Germany

sFLASH, the experimental setup for external seeding of free-electron lasers (FEL) at FLASH, has been operated in the high-gain harmonic generation (HGHG) mode. A detailed characterization of the laser-induced energy modulation, as well as the temporal characterization of the seeded FEL pulses is possible by using a transverse deflecting structure and an electron spectrometer. FEL saturation was reached for the 7th harmonic of the 266 nm seed laser. In this contribution, we present the latest experimental results.

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WEPAB022

Background-free Harmonic Production in XFELs via a Reverse Undulator Taper

undulator, FEL, background, electron

2618

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

Nonlinear harmonics in X-ray FELs can be parasitically produced as soon as FEL reaches saturation, or can be radiated in dedicated afterburners. In both cases there is a strong background at the fundamental, since it is much stronger than harmonics. One can get around this problem by application of the recently proposed reverse undulator tapering. In this contribution we present numerical simulations of harmonic production in such a configuration as well as recent results from FLASH where the second and the third harmonics were efficiently generated with a low background at the fundamental. We also present the results for a high-contrast operation when the afterburner is tuned to the fundamental.

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WEPAB026

BRho-Dependent Taylor Transfer Maps for Super-FRS Dipole Magnets

dipole, ion, simulation, multipole

2631

E.S. Kazantseva, O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
M. Berz, R. Jagasia, K. Makino
MSU, East Lansing, Michigan, USA
H. Weick, J.S. Winfield
GSI, Darmstadt, Germany

The Super-FRS is an in-flight projectile fragment separator being built at GSI for FAIR. Due to the required high design momentum resolution and large acceptance (Ah= ±40mrad, Av= ±20mrad) the dipole magnets of the Super-FRS have large apertures (38×14cm²). The wide design magnetic rigidity (BRho) range 2-20 Tm requires the variation of the main dipole magnetic field B0 in the range 0.16-1.6 T. Since the upper third of the B0 range is situated in a non-linear saturation region of the magnetization curve B(H) and the spatial distribution of magnetic permeability in the steel yoke is non-uniform, the field distribution in the useful aperture of the magnet is a non-linear and non-uniform function of the excitation current I. One consequence is the shortening of the effective length and the change of the field distribution with increasing I. In this study we analyze these effects for the Super-FRS dipole magnets. We use 3D field distribution from FEM simulations for different I values and a resulting BRho(I). From the fields the Taylor transfer maps for the particles are obtained using DA techniques (COSY-infinity) and the convergence of the resulting transfer maps is discussed.

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WEPAB027

Frequency Doubler and Two-color Mode of Operation at Free Electron Laser FLASH2

undulator, electron, operation, FEL

2635

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

We report on the results of the first operation of a frequency doubler at free electron laser FLASH2. The scheme uses the feature of the variable gap undulator. Undulator is divided in two parts. The second part of the undulator is tuned to the double frequency of the first part. Amplification process in the first undulator part is stopped at the onset of the nonlinear regime, such that nonlinear higher harmonic bunching in the electron beam density becomes pronouncing, but the radiation level is still small to disturb the electron beam significantly. Modulated electron beam enters the second part of the undulator and generates radiation at the 2nd harmonic. Frequency doubler allows operation in a two-color mode and operation at shorter wavelengths with respect to standard SASE scheme. Tuning of the electron beam trajectory, phase shifters and compression allows to tune intensities of the first and the second harmonic. The shortest wavelength of 3.1 nm (photon energy 400 eV) has been achieved with frequency doubler scheme, which is significantly below the design value for the standard SASE option.

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WEPAB029

Optimum Undulator Tapering of SASE FEL: From the Theory to Experiment

undulator, electron, FEL, laser

2639

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

Optimization of the amplification process in FEL amplifier with diffraction effects taken into account results in a specific law of the undulator tapering [*]. It is a smooth function with quadratic behavior in the beginning of the tapering section which transforms to a linear behavior for a long undulator. In practice, undulator consists of a sequence of modules of fixed length separated with intersections. Two modes of undulator tapering can be implemented: step tapering, and smooth tapering. Procedure of the step tapering applies step change of the undulator gap from module to module, and smooth tapering assumes additional linear change of the gap along each module. In this report we simulate the performance of the both experimental options and compare with theoretical limit.
[*] E.A. Schneidmiller and M.V. Yurkov, Optimization of a high efficiency free electron laser amplifier, Phys. Rev. ST Accel. Beams 18 (2015) 030705.

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WEPAB032

A Novel Optical Beam Concept for Producing Coherent Synchrotron Radiation with Large Energy Spread Beams

undulator, laser, electron, photon

2646

R. Rossmanith, A. Bernhard, V. Saile, P. Wesolowski
KIT, Karlsruhe, Germany
R.W. Aßmann, U. Dorda, B. Marchetti
DESY, Hamburg, Germany

Up to now two FEL concepts are known in conventional accelerators: 1.) In THz lasers an off-crest cavity adds a chirp to the bunch followed by a bunch compressor. Particles with different energies travel on different trajectories to the radiator. 2.) For EUV and X-ray FELs the beam enters an undulator which produces microbunches which then radiate. In this paper it is proposed to copy the THz laser scheme for EUV lasers. The incoming beam is chirped and a dogleg forces afterwards the particles with different energies to move on different parallel trajectories. Considering a detector plane perpendicular to the trajectories the particles with different energies arrive in general at different times. When in this plane for instance a TGU (Transverse Gradient Undulator) is positioned the emitted radiation in the TGU is monochromatic. If in addition chirp and dogleg are selected in such a way that the particles with different energies arrive at the same time at the entrance of the TGU the radiation is monochromatic and coherent similar to the THz laser concept.

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WEPAB033

Experimental Optimization and Characterization of Electron Beams for Generating IR/THz SASE FEL Radiation with PITZ

emittance, electron, FEL, simulation

2650

P. Boonpornprasert, Y. Chen, J.D. Good, H. Huck, I.I. Isaev, D.K. Kalantaryan, M. Krasilnikov, X. Li, O. Lishilin, G. Loisch, D. Melkumyan, A. Oppelt, H.J. Qian, Y. Renier, T. Rublack, F. Stephan
DESY Zeuthen, Zeuthen, Germany
G. Asova
INRNE, Sofia, Bulgaria
C. Saisa-ard
Chiang Mai University, Chiang Mai, Thailand
Q.T. Zhao
IMP/CAS, Lanzhou, People's Republic of China

The Photo Injector Test facility at DESY, Zeuthen site (PITZ), develops high brightness electron sources for modern linac-based Free Electron Lasers (FELs). The PITZ accelerator can also be considered as a suitable machine for the development of an IR/THz source prototype for pump-probe experiments at the European XFEL. One of the interesting options for the IR/THz generation with PITZ is to generate the radiation by means of a SASE FEL using an uncompressed electron beam with bunch length of a few 10 ps and a peak current of ~200 A. In this paper, results of experimental optimizations and characterizations, including transverse phase space, slice transverse emittance and longitudinal phase space, of electron beams with bunch charges of 4 nC are presented and discussed. The measurements were done with beam momenta of 15 MeV/c and 22 MeV/c. Results of IR/THz SASE FEL calculations by using the GENESIS1.3 code based on the measured beam parameters are also presented and discussed.

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WEPAB040

Upgrade Plan of Synchrotron Radiation Source at Hiroshima Synchrotron Center, Hiroshima University

storage-ring, synchrotron, emittance, synchrotron-radiation

2670

K. Kawase, S. Matsuba
HSRC, Higashi-Hiroshima, Japan

Hiroshima Synchrotron Radiation Center belonging to Hiroshima University is a user facility of the synchrotron radiation with the wavelength of ultraviolet range for natural science especially including materials and biological sciences. The kely apparatus is an electron storage ring with energy of 700 MeV. This machine is a racetrack shape with large two bending magnets and the injection energy is 150 MeV. It is a very compact size with the circumstance of 30 m, but it has only 2 insertion section and the emittance is much larger than the modern synchrotron radiation sources. Therefore, all of users is eager to upgrade the radiation source with several straight sections and low emittance beam keeping compactness. To meet these requests, we are designing the storage ring based on MAX-III. In this conference, we show the present design of the storage ring and its injector.

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WEPAB041

Status Report of Hiroshima Synchrotron Radiation Center Hiroshima University

undulator, synchrotron, synchrotron-radiation, photon

2672

S. Matsuba, K. Goto, K. Kawase
HSRC, Higashi-Hiroshima, Japan

The Hiroshima Synchrotron Radiation Center (HSRC) at Hiroshima University was established in 1996 for the research of solid state physics. The HSRC equips a 700 MeV electron storage ring nicknamed HiSOR. Recently, we are considering upgrade of the instrumentation beamline for the optical monitoring. In this paper, we report the present status of HSRC.

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WEPAB048

Present Status of Accelerators in Aichi Synchrotron Radiation Center

synchrotron, operation, synchrotron-radiation, storage-ring

2691

M. Hosaka, T. Ishida, A. Mano, A. Mochihashi, Y. Takashima
Nagoya University, Nagoya, Japan
Y. Hori, N. Yamamoto
KEK, Ibaraki, Japan
M. Katoh
UVSOR, Okazaki, Japan
S. Koda
SAGA, Tosu, Japan
H. Ohkuma, S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan

Aichi Synchrotron Radiation Center is a synchrotron radiation facility in operation since 2013. The electron energy of the storage ring is 1.2 GeV and the circumference is 72 m. In spite of the compact size of the storage ring, synchrotron radiation up to hard X-ray region (~20 keV) is available from the 5 T super conducting bending magnets. Presently (Dec. 2016), 8 beamlines (5 hard X-ray and 3 soft X-ray) are in operation and 2 new hard X-ray beamlines are under commissioning. This contribution reports on the present status as well as machine studies to improve the performance of the accelerators.

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WEPAB063

Considerations on Developing a Dedicated Terahertz Light Source Based on the HLS-II Storage Ring

storage-ring, synchrotron, synchrotron-radiation, electron

2716

S.W. Wang, J.Y. Li, W.B. Wu, W. Xu, K. Xuan, X. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

There is an increasing interest in generating terahertz radiation for different kinds of researches. A high-power terahertz light source can be realized through coherent synchrotron radiation from a storage ring. The radiation power of coherent synchrotron radiation is proportional to square of the number of electrons in a bunch. To generate coherent synchrotron radiation, the electron bunch length should be shorter than its radiation wavelength. This paper presents our preliminary study on developing a terahertz light source based on Hefei Light Source. We will introduce the status of Hefei Light Source (HLS) and discusses the approach to change it to a dedicated Terahertz light source using coherent synchrotron radiation. Several schemes are proposed to shorten the electron bunch length in the storage ring, including using a low alpha lattice, adopting a magnetic chicane and upgrading the RF system with much higher frequency. The related beam instabilities are also analyzed to predict the beam current threshold.

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WEPAB064

Upgrade Project on Top-Off Operation for Hefei Light Source

operation, injection, storage-ring, controls

2719

W. Xu, D. Jia, S.P. Jiang, C. Li, J.Y. Li, J.G. Wang, K. Xuan, Y.L. Yang, Q.B. Zeng, X. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Hefei Light Source has successfully finished a major upgrade project and has been officially opened to users since January 2015. The upgrade project mainly includes increasing the linac injector energy from 200 MeV to 800 MeV which is the same as the ring energy, changing the ring lattice structure from TBA to DBA in order to provide more straight sections for insertion devices while keeping the circumference unchanged, and lowering the beam emittance to obtain higher photon brightness. Before the upgrade project, decay mode is the only choice for the operation of Hefei Light Source. This is because the injected beam from the linac injector needs to be ramped up to 800 MeV after injection. At prensent we have the conditions to operate Hefei Light Source with top-off mode since the linac can perform full-energy and bunch-by-bunch injection. The main challenge for the top-off operation is to control the radiation dose for personal and equipment safety, and to maintain high stability and reliability of the injector. In this paper, we report our work on the top-off operation project for Hefei Light Source.

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WEPAB065

Proposal for the Generation of Terawatt, Attosecond X-Ray Pulses in Free Electron Lasers

undulator, laser, electron, FEL

2723

Z. Wang, C. Feng, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

A feasible novel method is proposed to generate attosecond terawatt X-ray radiation pulse in free electron lasers, which could find its application on multiple science fields. In our scheme, a chirped laser is employed to generate a chirped periodic current enhancement and a series of spatiotemporal shifters are applied between the undulator sections to generate ultra-short radiation pulse. Three-dimensional start-to-end simulations are carried out and the calculation results show that a 0.15nm X-ray pulse with the peak power of about 1TW and the pulse length of 0.1fs could be achieved in our scheme.

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WEPAB066

POP Experiment for the HB-HGHG Scheme at SXFEL

electron, laser, FEL, free-electron-laser

2727

K.S. Zhou, H.X. Deng, C. Feng, D. Wang
SINAP, Shanghai, People's Republic of China

Abstract High brightness, fully coherent and ultra-short free electron lasers (FEL) operating in the soft x-ray region are opening up new frontiers in many scientific fields. In this paper, we perform the design studies for the proof-of-principle experiment of the recently proposed HB-HGHG scheme at SXFEL test facility with a two-stage setup. The first stage of SXFEL is used for the generation of the coherent signal at 30th harmonic of the seed through the coherent harmonic generation process. Then this coherent signal is shifted ahead by the 'fresh bunch' chicane of SXFEL and initiates the strong coherent radiation in the radiator of the second stage of SXFEL. The output properties have been compared with the conventional EEHG and the two-stage cascaded HGHG with the same harmonic up-conversion number.

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WEPAB089

Design Study for the Generation of Few-Cycle FEL Pulses Using Mode-Locked Afterburner Scheme at Clara

FEL, bunching, laser, simulation

2783

C.L. Shurvinton, D.J. Dunning, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Ultrashort pulse operation in FELs is a highly desirable capability for imaging matter on ultrafast timescales. This paper presents a design study for a proof-Âof-Âprinciple demonstration of the mode-locked afterburner (ML-AB) scheme on the FEL test facility CLARA. A start-to-end simulation has been constructed using the time-Âdependent three-Âdimensional FEL code GENESIS 1.3 to evaluate the performance of the scheme. The ability to produce pulses of several femtoseconds in duration with peak powers of the order of 100 MW at 100 nm wavelength is predicted.Â Such pulses have duration of 2 fs (6 optical cycles), a factor of ~5 shorter than the FEL cooperation length. Potential routes for further optimisation and alternative operating modes are explored.

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WEPAB108

Angular Trajectory Kicks in a High-Gain Free-Electron Laser

electron, FEL, laser, free-electron-laser

2830

P. Baxevanis, Z. Huang, G. Stupakov
SLAC, Menlo Park, California, USA

In a free-electron laser (FEL), transverse momentum offsets (or kicks) are introduced either inadvertently (through wakefields or mis-steering of the electron beam) or as part of dedicated schemes that require off-axis radiation propagation. Studying the influence of this effect on the performance of machines such as LCLS-I/II is critical both from a tolerance point of view and for its practical applications. A theoretical analysis of a high-gain FEL driven by such a kicked beam will be presented, with a critical evaluation of previous studies.

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WEPAB127

EMuS Target Station Studies

proton, solenoid, target, neutron

2871

N. Vassilopoulos, Z.L. Hou, Y. Yuan, G. Zhao
IHEP, Beijing, People's Republic of China

The experimental muon source (EMuS) is a high-intensity muon source at China Spallation Neutron Source (CSNS), aiming to combine muSR applications, R&D efforts for a future muon-decay based neutrino beam, and neutrino cross-section measurements. The proton beam has 4 kW of power and is provided by the rapid cycling synchrotron (RCS) of CSNS to a capture system that consists of an adiabatic superconductive solenoid with a maximum field of 5 T and a graphite target located inside the first coil, in order to maximize muons/pions capture and reduce their transverse momentum. In this article we present the challenging target system and the optimization studies that led to the current 4-coil/3-step design. The challenge arises from the necessary extraction of the spent proton beam along the downstream area of the capture solenoid through a hole, in order to separate it from the muons and pions. In addition, shielding studies are presented in order to examine the effectiveness of the shields on the coils and the low radiation damage expected in the system.

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WEPIK015

Optimized Monochromatization for Direct Higgs Production in Future Circular e⁺e⁻ Colliders

collider, luminosity, emittance, electron

2950

F. Zimmermann
CERN, Geneva, Switzerland
M.A. Valdivia García
DCI-UG, León, Mexico

Funding: This work was supported in part by the European Commission under the HORIZON2020 Integrating Activity project ARIES, grant agreement 730871, and by the Mexican CONACyT ‘‘BEAM'' Programme.
Direct s-channel Higgs production in e⁺e⁻ collisions is of interest if the centre-of-mass energy spread can be reduced to be comparable to the width of the standard model Higgs boson. A monochromatization scheme could be employed in order to achieve the desired reduction, by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In high-energy high-luminosity circular colliders, beamstrahlung may increase the energy spread and bunch length. The horizontal emittance blow up due to beamstrahlung, a new effect not present in past monochromatization proposals, may degrade the performance, especially the luminosity. We study, for the FCC-ee at 62.5 GeV beam energy, how we can optimize the IP optics parameters (betax*, Dx*) along with the number of particles per bunch so as to obtain maximum luminosity at a desired target value of the collision energy spread.

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WEPIK021

MDI Issues in CEPC Double Ring

quadrupole, detector, synchrotron, synchrotron-radiation

2965

B. Sha, J. Gao, Y. Wang, C.H. Yu
IHEP, Beijing, People's Republic of China

With the discovery of the higgs boson at around 125GeV, a circular higgs factory design with high luminosity (L ~ 10³⁴ cm^-2 s^-1) is becoming more popular in the accelerator world. The CEPC project in China is one of them. Machine Detector Interface (MDI) is the key research area in electron-positron colliders, especially in CEPC, it is one of the criteria to measure the accelerator and detector design performance. Because of the limitation from the existing tunnel, many equipment including magnets, beam diagnostic instruments, masks, vacuum pumps, and components of the detector must coexist in a very small region. In this paper, some important MDI issues will be reported for the Interaction Region (IR) design, e.g. the final doublet quadrupoles physics design parameters, beam-stay-clear region and beam pipe, synchrotron radiation power and critical energy are also calculated.

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WEPIK023

Sawtooth Effect in CEPC

synchrotron, synchrotron-radiation, lattice, closed-orbit

2971

H. Geng, J. Gao, B. Sha, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
IHEP, Beijing, People's Republic of China

Funding: This work was supported by National Natural Science Foundation of China, under contract NO. 11405188.
CEPC is a circular electron and positron machine designed to study the property of the Higgs boson. The beam energy for CEPC is thus chosen to be 120GeV. At such a high energy, synchrotron radiation has pronounced effect on the beam behavior. In this paper, we will show the synchrotron radiation effect in the CEPC single ring design, namely, the closed orbit, linear optics and dynamic aperture. Analytical analysis will be given trying to explain the phenomenon.

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WEPIK024

HTS-Coated Beam Screen for SPPC Bending Magnets

synchrotron, proton, cryogenics, synchrotron-radiation

2974

P.P. Gan, Q. Fu, H.P. Li, Y.R. Lu, K. Zhu
PKU, Beijing, People's Republic of China
Y.D. Liu, J.Y. Tang, Q.J. Xu
IHEP, Beijing, People's Republic of China

For studying new physics beyond the Standard Model, Supper proton-proton Collider (SPPC) with a circumfer-ence of 100 km and a centre mass energy of 100 TeV is proposed and under study in China. Due to the high particle energies and 16 T high magnet field, the synchrotron radiation power emitted from the proton beams reaches 48.5 W/m in the bending magnets, two orders of magnitude higher than that of LHC. A novel beam screen is anticipated to screen cold chamber walls from the massive synchrotron radiation power and transfer the heat load to cryogenic cooling fluid. For drastically reducing resistive wall impedance and saving refrigerator power, we have studied high temperature superconductor (HTS) coated beam screen operating in liquid nitrogen temperature area. Singly from the point of temperature, the feasibility of HTS-coated beam screen is demonstrated by steady-state thermal analysis. Two kinds of potential HTS material are also discussed in this paper.

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WEPIK048

Evaluation and Mitigation of Synchrotron Radiation Background in the eRHIC Ring-Ring Interaction Region

detector, electron, photon, quadrupole

3032

C. Montag
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.
Synchrotron radiation is a potential source of background in the detector of any future electron-ion collider. In the case of the eRHIC ring-ring design, a 22mrad crossing angle eliminates the need for a separator dipole, which would otherwise be a major source of synchrotron radiation. However, electrons in the transverse tails experience strong magnetic fields in the low-beta quadrupoles near the interaction point. Despite the low electron density in the tails the resulting hard radiation generated in these strong fields is a major concern, and a set of masks needs to be in place to shield the detector from these photons. We present simulation studies and a first design of a synchrotron radiation masking scheme.

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WEPIK062

UNDUMAG - A New Computer Code to Calculate the Magnetic Properties of Undulators

undulator, synchrotron, damping, synchrotron-radiation

3071

M. Scheer
HZB, Berlin, Germany

A new code for the magnetic design of undulators is under development at the Helmholtz-Zentrum Berlin (BESSY). The program reads in the geometry and material properties of the undulator magnets and iron poles. Magnetic fields, forces and torques, as well as trajectories and synchrotron radiation can be calculated. The code is a stand-alone FORTRAN program, thus, only a FORTRAN compiler is needed to install it. Build-in graphic routines allows to write postscript files to visualize the geometry and the fields. Other results like 3D field maps, field integrals etc. are written to ASCII files for later use. The code will be published under the GNU general public license. First results and comparison to other codes are presented.

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WEPIK073

Three Dimensional Wake Field for an Electron Moving in Undulator

undulator, electron, electromagnetic-fields, wakefield

3098

K. Ohmi
KEK, Ibaraki, Japan

Electro-magnetic field for given trajectory of an electron is calculated by Lienard-Wiechert potential. The field near the electron moving in an undulator is presented. The field is regarded as a wake field in the undulator. Motion of a bunch is studied in the wake field.

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WEPIK121

Computation of Synchrotron Radiation on Arbitrary Geometries in 3D with Modern GPU, Multi-Core, and Grid Computing

GPU, undulator, simulation, brightness

3238

D.A. Hidas
BNL, Upton, Long Island, New York, USA

Funding: Supported by the U.S. Department of Energy under contract DE-SC0012704
Open Source Code for Advanced Radiation Simulation (OSCARS*) is an open source project being developed at Brookhaven National Laboratory for the computation of synchrotron radiation from arbitrary particle beams in arbitrary magnetic (and electric) fields on arbitrary geometries in 3D. OSCARS was designed with considerations for modern large scale computing infrastructure. These include the ability to use GPUs for computations, multi-threaded computations, and utilities for grid (or cloud) computing. Primary applications include, but are not limited to, the computation of spectra, photon flux densities, and notably, power density distributions on arbitrary geometries in 3D which is of interest in accelerator component study and design. This modern approach and several complex geometries will be highlighted and elaborated on.
* http://oscars.bnl.gov

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WEPVA029

SIS100 Tunnel Design and Status

shielding, site, operation, extraction

3316

C. Omet, J. Falenski, G. Fehrenbacher, H. Kisker, K. Konradt, A. Sokolov, P.J. Spiller
GSI, Darmstadt, Germany
A. Fischer
FAIR, Darmstadt, Germany

As the FAIR project is proceeding, many of the building and tunnel designs in the meanwhile are frozen and documents are prepared for tendering. For the future FAIR driver accelerator, SIS100, the accelerator tunnel T110 comprises a 1100 m long tunnel, which has a depth of 17 m under ground. In this paper, its environmental boundary conditions, design principles and the finally chosen layout are presented.

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WEPVA043

Study of the Suitability of 3D Printing for Ultra-High Vacuum Applications

vacuum, laser, electron

3356

S. Jenzer, M. Alves, N. Delerue, A. Gonnin, D. Grasset, F. Letellier-Cohen, B. Mercier, E. Mistretta, C. Prevost
LAL, Orsay, France
A. Vion
BV Proto, Sévenans, France
J-P. Wilmes
AGS Fusion, Izernore, France

Funding: IN2P3/CNRS
In the recent year additive fabrication (3D printing) has revolutionized mechanical engineering by allowing the quick production of mechanical components with complex shapes. So far most of these components are made in plastic and therefore can not be used in accelerator beam pipes. We have investigated samples printed using a metal 3D printer to study their behavior under vacuum. We report on our first tests showing that such samples are vacuum compatible and comparing pumping time.

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WEPVA066

The ESS Target Proton Beam Imaging System as in-Kind Contribution

target, proton, neutron, operation

3422

E. Adli, R. Andersson, D.M. Bang, O. Dorholt, H. Gjersdal, O. Røhne
University of Oslo, Oslo, Norway
M.G. Ibison, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
S. Joshi
University College West, Trollhätan, Sweden
T.J. Shea, C.A. Thomas
ESS, Lund, Sweden

Funding: This work is part of the Norwegian in-kind contribution to ESS.
The ESS Target Proton Beam Imaging System will image the 5 MW ESS proton beam as it enters the spallation target. The system will operate in a harsh radiation environment, leading to a number of challenges: development of radiation hard photon sources, long aperture-restricted optical paths, and fast electronics to provide rapid response to beam anomalies. The newly formed accelerator group at the University of Oslo is the in-kind partner for the Imaging System. This paper outlines the main challenges of the Imaging System and how they are addressed within the collaborative nature of the in-kind project.

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WEPVA067

Preliminary Results on the Resonant Excitation of THz Wakefield in a Multi-Mode Dielectric Loaded Waveguide by Bunch Train

electron, wakefield, experiment, space-charge

3426

D. Wang, Y.-C. Du, W. Gai, W.-H. Huang, L. Niu, X.L. Su, C.-X. Tang, Q.L. Tian, L.X. Yan
TUB, Beijing, People's Republic of China
S.P. Antipov
Euclid TechLabs, LLC, Solon, Ohio, USA
Y.F. Liang
Tsinghua University, Beijing, People's Republic of China

Funding: Work supported by the National Nature Science Foundation of China (NSFC Grants No.11475097) and the National Key Scientific Instrument and Equipment Development Project of China (Grants No. 2013YQ12034504)
We report the preliminary experimental results on the resonant excitation of THz wakefield in a multi-mode dielectric loaded waveguide (DLW) by electron bunch train at the Tsinghua University accelerator beamline. The bunch train with certain longitudinal periodicity was generated based on nonlinear longitudinal space charge oscillation [1]. By passing such bunch train through a multi-mode DLW, we observed selective excitation of the fifth longitudinal mode (TM05 mode) was resonantly excited. Future experiment plan is to tune the bunch train interval with a chicane in the beamline in order to selectively excite arbitrary mode for tunable THz radiation source with multi-mode DLWs.
*wangdan16@mail.tsinghua.edu.cn
*yanlx@mail.tsinghua.edu.cn

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WEPVA113

Thermo-Physical and Mechanical Characterisation of Novel Materials under Development for HL-LHC Beam Intercepting Devices

luminosity, experiment, laser, framework

3536

O. Sacristan De Frutos, A. Bertarelli, L. Bianchi, F. Carra, J. Guardia, M. Guinchard, S. Redaelli
CERN, Geneva, Switzerland

Funding: The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD-2, grant agreement no.312453
The collimation system for high energy particle accelerators as HL-LHC, must be designed to withstand the close interaction with intense and energetic particle beams, safely operating over an extended range of temperatures in extreme conditions (pressure, strain-rate, radiation), which are to become more demanding with the High Luminosity LHC. In order to withstand such conditions, the candidate materials must possess among other properties outstanding thermal shock resistance and high thermal and electrical conductivity, condition only met by advanced or novel materials. Therefore, an extensive R&D program has been launched to develop novel materials capable of replacing or complementing materials used for present collimators. So far, Molybdenum Carbide - Graphite and Copper-Diamond composites have been identified as the most promising materials. Literature data are scarce or non-existing for these materials. For this reason the successive characterisation campaigns constitute a linchpin of the R&D program. This paper reviews the experimental program followed for the thermo-physical and mechanical characterisation of the materials, and discusses the most relevant results.

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WEPVA114

Optimising Machine-Experiment Interventions in HL-LHC

shielding, operation, experiment, vacuum

3540

F. Sanchez Galan, C. Adorisio, I. Bergstrom, D. Brethoux, S. Evrard, A. Gaddi, L.P. Krzkempek, M. Lazzaroni, J. Perez Espinos, M. Raymond, H. Vincke
CERN, Geneva, Switzerland

Funding: This Research is supported by the HL-LHC project
The luminosity reach of the HL-LHC experiments implies new constraints for the protection of the inner triplets from the machine debris. In general activation levels will increase a factor of 15-30 from the 2015 values (LS1), affecting both radiation tolerance of equipment and maintenance scenarios. The design of new equipment takes into account these constraints and the entire layout of tunnel equipment near the interaction regions will al-low for simplified maintenance. In particular, new ab-sorbers will replace the existing protection of the ma-chine-experiment cavern boundaries, with an optimised layout of the region. This paper summarises the main constraints (both physical and operational) existing at the region, together with the solutions adopted to reduce worker's dose.

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WEPVA122

Two Year Operational Experience With the Tps Vacuum System

vacuum, storage-ring, synchrotron, operation

3557

Y.C. Yang, C.K. Chan, J. -Y. Chuang, Y.T. Huang, C.C. Liang, I.C. Sheng
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS), a 3-GeV third generation synchrotron light source, was commissioned in 2014 December and is now currently operated in top-up mode at 300mA for users. During the past two years, the machine was completed to meet design goals with among others the installation of superconducting cavities (SRF), the installation of insertion devices (ID) and the correction of vacuum chamber structure downstream from the IDs. The design goal of 500mA beam current was achieved with a total accumulated beam dose of more than 1000Ah, resulting in three orders of magnitude reduction of out-gassing. As the beam current was increased, a few vacuum problems were encountered, including vacuum leaks, unexpected pressure bursts, etc. Vacuum related issues including high pressure events, lessons learned and operational experience will be presented and discussed in this paper.

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WEPVA127

Design of a 3.5 T Superconducting Multipole Wiggler

vacuum, photon, wiggler, simulation

3564

J.C. Jan, C.-H. Chang, H.-H. Chen, S.D. Chen, T.Y. Chung, C.-S. Hwang, F.-Y. Lin, G.-H. Luo
NSRRC, Hsinchu, Taiwan

A 3.5 T superconducting multipole wiggler (SMPW) has been designed through the collaboration of National Synchrotron Radiation Research Center (NSRRC) and Synchrotron Light Research Institute (SLRI). The SMPW will support the hard X-ray source for the X-ray absorption spectroscopy (XAS) beamline in SLRI. The design concept of the SMPW follows from, and improves on, the operating experience of the superconducting magnet in NSRRC. An improvement of the operation and compatible with the cooling capacity of the cryogenic system, is the design goal. A quick and easy recovery of the magnet from a quench event is also required. The design of the magnet circuit and the mechanical of the SMPW are also discussed herein.

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WEPVA132

Switching Power Supply Automatic Test System in Taiwan Photon Source

photon, power-supply, synchrotron, simulation

3580

Y.S. Wong, C.Y. Liu, K.-B. Liu, B.S. Wang
NSRRC, Hsinchu, Taiwan

This paper studies the use of a novel switching power supply automatic test system used in Taiwan photon source, Model 8000 is the ultimate solution for power electronic testing, the system includes a wide range of hardware choice such as AC/DC source, electronic loads, DMM, oscillate scope, noise analyzer and short/OVP tester. The ATS 8000 system uses a unique test command optimazation technology to prevent repetitive control commands from being sent to system hardware devices. This improve test speed dramatically and makes ideal choice for both high speed production applications as well as design verification.

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WEPVA137

Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project

vacuum, photon, storage-ring, lattice

3590

B.K. Stillwell, B. Billett, B. Brajuskovic, J.A. Carter, E.S. Kirkus, M.A. Lale, J.E. Lerch, J. R. Noonan, M.M. O'Neill, B.G. Rocke, K.J. Suthar, D.R. Walters, G.E. Wiemerslage, J. Zientek
ANL, Argonne, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction, and rf cavity straight sections. An overview of progress in these areas is presented.

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WEPVA138

The RaDIATE High-Energy Proton Materials Irradiation Experiment at the Brookhaven Linac Isotope Producer Facility

target, proton, experiment, linac

3593

K. Ammigan, P. Hurh, R.M. Zwaska
Fermilab, Batavia, Illinois, USA
A. Amroussia, C.J. Boehlert
Michigan State University, East Lansing, Michigan, USA
M.S. Avilov, F. Pellemoine
FRIB, East Lansing, USA
M. Calviani, E. Fornasiere, A. Perillo-Marcone, C. Torregrosa
CERN, Geneva, Switzerland
A.M. Casella, D.J. Senor
PNNL, Richland, Washington, USA
C.J. Densham
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
T. Ishida, S. Makimura
KEK, Ibaraki, Japan
V.I. Kuksenko, S.G. Roberts
University of Oxford, Oxford, United Kingdom
Y. Lee, T.J. Shea, C.A. Thomas
ESS, Lund, Sweden
L.F. Mausner, D. Medvedev, N. Simos
BNL, Upton, Long Island, New York, USA
E. Wakai
KEK/JAEA, Ibaraki-Ken, Japan

Funding: Work supported by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) was founded in 2012 to bring together the high-energy accelerator target and nuclear materials communities to address the challenging issue of radiation damage effects in beam-intercepting materials. Success of current and future high intensity accelerator target facilities requires a fundamental understanding of these effects including measurement of materials property data. Toward this goal, the RaDIATE collaboration organized and carried out a materials irradiation run at the Brookhaven Linac Isotope Producer facility (BLIP). The experiment utilized a 181 MeV proton beam to irradiate several capsules, each containing many candidate material samples for various accelerator components. Materials included various grades/alloys of beryllium, graphite, silicon, iridium, titanium, TZM, CuCrZr, and aluminum. Attainable peak damage from an 8-week irradiation run ranges from 0.03 DPA (Be) to 7 DPA (Ir). Helium production is expected to range from 5 appm/DPA (Ir) to 3,000 appm/DPA (Be). The motivation, experimental parameters, as well as the post-irradiation examination plans of this experiment are described.

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THOBA1

Studies of the Micro-Bunching Instability in Multi-Bunch Operation at the ANKA Storage Ring

synchrotron, bunching, photon, storage-ring

3645

M. Brosi, E. Blomley, E. Bründermann, M. Caselle, B. Kehrer, A. Kopmann, A.-S. Müller, L. Rota, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber
KIT, Eggenstein-Leopoldshafen, Germany

Funding: Supported by the German Federal Ministry of Education and Research (05K13VKA & 05K16VKA), the Helmholtz Association (VH-NG-320) and the Helmholtz International Research School for Teratronics (HIRST)
The test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and can generate brilliant coherent synchrotron radiation (CSR) in the THz range employing a dedicated bunch length-reducing optic at 1.3 GeV beam energy. The high degree of spatial compression leads to complex longitudinal dynamics and to time evolving sub-structures in the longitudinal phase space of the electron bunches. The results of the micro-bunching instability are time-dependent fluctuations and strong bursts in the radiated THz power. To study these fluctuations in the emitted THz radiation simultaneously for each individual bunch in a multi-bunch environment, fast THz detectors are combined with KAPTURE, the dedicated KArlsruhe Pulse Taking and Ultrafast Readout Electronics system, developed at KIT. In this contribution we present measurements conducted to study possible multi-bunch effects on the characteristic bursting behavior of the micro-bunch instability.

Slides THOBA1 [12.910 MB]

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THOBA2

Coherent Synchrotron Radiation and Wake Fields With Discontinuous Galerkin Time Domain Methods

vacuum, wakefield, synchrotron, synchrotron-radiation

3649

D. A. Bizzozero, H. De Gersem, E. Gjonaj
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by DESY, Hamburg.
Coherent synchrotron radiation (CSR) is an essential issue in modern accelerators. We propose a new method to examine CSR in the time domain using an unstructured Discontinuous Galerkin (DG) method. The method uses a 2D spatial discretization in the longitudinal and transverse coordinates (Z,X) with a Fourier series decomposition in the transverse coordinate Y and computes the fields modally. Additionally, by alignment of mesh element interfaces along a source reference orbit, DG methods can naturally handle discontinuous or thin sources in the transverse X direction. We present an overview of the method, illustrate it by calculating wake potentials in a model problem, and in a bunch compressor.

Slides THOBA2 [2.526 MB]

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THOAB1

Study of Medical Applications of Compact Laser-Compton Light Source

laser, electron, synchrotron, scattering

3656

Y. Hwang, T. Tajima
UCI, Irvine, California, USA
G.G. Anderson, C.P.J. Barty, D.J. Gibson, R.A. Marsh
LLNL, Livermore, California, USA

Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Compton scattering of laser photons by a relativistic electron beam produces monoenergetic, tunable and small source size X-rays similar to synchrotron light sources in a very compact setting, due to the shorter undulator period of lasers. These X-ray sources can bring to every hospitals advanced radiology and radiotherapy that are currently only being conducted at synchrotron facilities. Few examples include phase contrast imaging utilizing the micron-scale source size, K-edge subtraction imaging from two monoenergetic X-rays at different energies and radiation therapy using radiosensitization of high-Z nanoparticles. At LLNL, 30 keV X-rays have been generated from the 30 MeV X-band linac, and the X-rays have been characterized and agree with the modeling very well. This source is being used to study the feasibility of aforementioned medical applications. Experimental setup of K-edge subtraction of contrast agents are presented, demonstrating the low-dose, high-contrast imaging potential of the light source. Plans to study enhanced radiotherapy using Gold nanoparticles with the upgrade of the machine to higher energies are discussed.

Slides THOAB1 [2.818 MB]

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THPAB001

Microbunching Instability as a Caustic Phenomenon

electron, linac, bunching, synchrotron

3676

T.K. Charles, D.M. Paganin
Monash University, Faculty of Science, Clayton, Victoria, Australia
M.J. Boland
The University of Melbourne, Melbourne, Victoria, Australia
M.J. Boland, R.T. Dowd
SLSA, Clayton, Australia

Microbunching instability if left alone, threatens to degrade the beam quality of high brightness electron beams in Free Electron Lasers. Recently, caustic formation in electron trajectories was identified as a mechanism describing current modulations in accelerated particle beams. Here we consider CSR-induced microbunching as a caustic phenomenon. This analysis reports on the influence of longitudinal dispersion, R56, on the microbunching process, as well as elucidating the influence of the second and third order longitudinal dispersion values, T566 and U5666.

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THPAB002

Update of the Collective Effects Studies for Sirius

impedance, simulation, undulator, operation

3680

F.H. de Sá, H.O.C. Duarte, L. Liu
LNLS, Campinas, Brazil

An updated impedance budget for Sirius, with contributions from 3D electromagnetic simulations and analytic calculations, is presented and the estimates for single and multi-bunch instability thresholds for the first operation phase are re-evaluated.

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THPAB012

Beam Transport Optimization for Applying an SRF Gun at the ELBE Center

electron, gun, SRF, linac

3712

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

An SRF gun at the ELBE center has been operated with a magnesium cathode. Electron beams were produced with a maximum bunch charge of 200 pC and an emit-tance of 7.7 μm. Simulations have been conducted with ASTRA and Elegant for applying the SRF gun to ELBE user experiments, including neutron beam generation, positron beam generation, THz radiation and Compton backscattering experiment. Beam transport has been optimized to solve the best beam performance for these user stations at the bunch charge of 200 pC. Simulation results indicate that the SRF gun is potential to benefit the high bunch charge applications at ELBE.

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THPAB036

An Experimental Study of Beam Dynamics in the ERL-Based Novosibirsk Free Electron Laser

FEL, diagnostics, electron, synchrotron

3781

V.M. Borin, L.M. Schegolev, O.A. Shevchenko, N.A. Vinokurov
BINP SB RAS, Novosibirsk, Russia
V.L. Dorokhov, O.I. Meshkov
BINP, Novosibirsk, Russia

Transverse and longitudinal dynamics of the electron beam of the Novosibirsk infrared Free Electron Laser is studied. The Novosibirsk FEL is based on the multi-turn energy recovery linac (ERL). The ERL operate in CW mode with an average current about 10 mA. Therefore non-destructive beam diagnostics is preferable. The beam energy at the last track of the ERL is 42 MeV. As a result, significant part of synchrotron radiation from bending magnets is in the visible range. The transverse beam dimensions were measured with the optical diagnostics before and after the undulator applied for generation of middle-infrared coherent radiation. The obtained data is used to calculate the beam energy spread and emittance. The longitudinal beam dynamics was studied with electro-optical dissector.

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THPAB060

pyAT: A Python Build of Accelerator Toolbox

lattice, interface, synchrotron, synchrotron-radiation

3855

W.A.H. Rogers
DLS, Oxfordshire, United Kingdom
N. Carmignani, L. Farvacque, B. Nash
ESRF, Grenoble, France

Accelerator Toolbox* (AT) is a particle accelerator modelling tool originally written in MATLAB. It is used at many accelerator facilities, particularly synchrotron light sources, as an on-line model and is also used for off-line beam dynamics studies. For speed of execution, the tracking engine of AT was written in C and compiled for use in MATLAB. The C-based implementation allowed re-use of of the tracking engine compiled against the core Python libraries to create a Python version of AT. For additional purposes of speed, the C interface to the integration routines has been modified allowing equal speeds for both MATLAB and Python interfaces, with an increase in speed relative to the original MATLAB version. This paper describes the adaptation process, including adapting the MATLAB build, creating the Python build and laying the foundations for the additional Python library implementation. Speed benchmarks are included with comparison to other tracking codes Elegant and MADX.
* A. Terebilo, Accelerator Toolbox for MATLAB, SLAC-PUB-8732 (2001)

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THPAB073

Magnetized and Flat Beam Experiment at FAST

emittance, electron, quadrupole, cathode

3876

A. Halavanau, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J. Hyun
Sokendai, Ibaraki, Japan
D. Mihalcea, P. Piot, T. Sen, J.C.T. Thangaraj
Fermilab, Batavia, Illinois, USA

A photocathode, immersed in solenoidal magnetic field, can produce canonical-angular-momentum (CAM) dominated electron beams. Such beams have an application in electron cooling of hadron beams and can also be uncoupled to yield asymmetric-emittance (flat) beams. In the present paper we explore the possibilities of the flat beam generation at Fermilab's Accelerator Science and Technology (FAST) facility linear accelerator. We present optimization of the beam flatness and four-dimensional transverse emittance and investigate the mapping and its limitations of the produced eigen-emittances to conventional emittances using a skew-quadrupole channel. Possible application of flat beams at the FAST facility are also discussed.

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THPAB076

Coherent Synchrotron Radiation Simulations for Off-Axis Beams Using the Bmad Toolkit

lattice, simulation, synchrotron, synchrotron-radiation

3887

D. Sagan, C.E. Mayes
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Coherent synchrotron radiation (CSR) potentially limits operation accelerators with high bunch charges and/or short bunch lengths by increasing energy spread, and by Except at the lowest beam energies, the one dimensional treatment of coherent synchrotron radiation (CSR) originally developed by Saldin is an efficient and reasonably accurate way to simulate the effects of CSR on a particle beam. A possible problem with standard implementations of the 1D CSR formalism is that these implementations assume that the beam centroid is close to the reference trajectory that defines the lattice. In this paper, the one dimensional treatment is extended to take into account beams whose centroid is far from the reference trajectory and an example using the Cornell-BNL Fixed Field Alternating Gradient (FFAG) accelerator CBETA is given.

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THPAB085

Simulations of Coherent Synchrotron Radiation on Parallel Hybrid GPU/CPU Platform

simulation, GPU, emittance, synchrotron

3915

B. Terzić, D. Duffin, A.L. Godunov
ODU, Norfolk, Virginia, USA
A. Arumugam, T. Islam, D. Ranjan, S. Sangam, M. Zubair
ODU CS, Norfolk, Virginia, USA

Funding: National Science Foundation 1535641
Coherent synchrotron radiation (CSR) is an effect of self-interaction of an electron bunch as it traverses a curved path. It can cause a significant emittance degradation, as well as fragmentation and microbunching. Numerical simulations of the 2D/3D CSR effects have been extremely challenging due to computational bottlenecks associated with calculating retarded potentials via integrating over the history of the bunch. We present a new high-performance 2D, particle-in-cell code which uses massively parallel multicore GPU/GPU platforms to alleviate computational bottlenecks. The code formulates the CSR problem from first principles by using the retarded scalar and vector potentials to compute the self-interaction fields. The speedup due to the parallel implementation on GPU/CPU platforms exceeds three oders of magnitude, thereby bringing a previously intractable problem within reach. The accuracy of the code is verified against analytic 1D solutions (rigid bunch) and semi-analytic 2D solutions for the chirped bunch. Finally, we use the new code in conjunction with a genetic algorithm to optimize the design of a fiducial chicane.

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THPAB119

Study on a Time-Domain Spectroscopy System for Coherent Terahertz Pulse Spectrum Measurement from 5 MeV Electron Beam

laser, electron, polarization, detector

4003

R. Yanagisawa, T. Toida
Waseda University, Tokyo, Japan
K. Kan
ISIR, Osaka, Japan
K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
M. Washio
RISE, Tokyo, Japan

Funding: This work was supported by a research granted from The Murata Science Foundation and JSPS KAKENHI 26286083.
Terahertz wave, expected to apply spectral analysis and imaging, has recently developed both source and detector components. For the terahertz source, the coherent radiation from electron linac is expected to be the high power terahertz source. At Waseda University, we have been studying high quality electron beam generation using Cs-Te photocathode RF-Gun and its application. We tried to generate terahertz wave by the coherent radiation and to measure its spectrum by a time-domain spectroscopy (TDS) technique. Adopting this technique, ultra-short laser pulse is needed as probe light. A terahertz waveform appears by delaying the timing of probe pulse. A spectrum of terahertz wave is also led by the waveform, by using the Fourier transform. We succeeded in constructing the probe laser system operating at 119 MHz repetition rate. The pulse duration was compressed down to 190 fs (FWHM) by using pulse compressor. We also succeeded in measuring a terahertz radiation from a photoconductive antenna. In this conference, we will report the outline of our terahertz TDS system, recent progress of our laser system, and terahertz wave generation and detection, with the future prospects.

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THPAB132

MCP Based Detectors Installation in European XFEL

detector, photon, ion, laser

4031

E. Syresin, O.I. Brovko, A.Yu. Grebentsov
JINR, Dubna, Moscow Region, Russia
W. Freund
XFEL. EU, Hamburg, Germany
J. Grünert
European XFEL, Schenefeld, Germany
M.V. Yurkov
DESY, Hamburg, Germany

An important task of the photon beam diagnostics at the European XFEL is providing reliable tools for measurements aiming at the search for and fine tuning of the amplification process in the SASE FEL. Radiation detectors based onμchannel plates (MCP) were prepared for such measurements. These detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ to 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 5.1 nm for SASE3. Photon pulse energies are measured at the MCP anode and with a photodiode. The transverse photon beam profile is measured by an MCP imager with phosphor screen anode. Three MCP devices are being installed, one in each of the three FEL beamlines (SASE1, SASE2, and SASE3). The units for SASE1 and SASE3 were already installed in the XFEL tunnel, and the technical commissioning of the MCP detectors and their electronics is progressing. Calibration and acceptance test experiments with beam are scheduled for early 2017.

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THPAB149

Characterization of the THz Radiation-Based Bunch Length Measurement System for the NSRRC Photoinjector

laser, electron, detector, software

4080

C.C. Liang, B.Y. Chen, C.H. Chen, M.C. Chou, S. Fann, C.S. Huang, N.Y. Huang, J.-Y. Hwang, W.K. Lau, A.P. Lee, T.Y. Lee, W.Y. Lin, T.-C. Yu
NSRRC, Hsinchu, Taiwan

A part of high brightness photo-injection (HBI) project at NSRRC is intending to adopt Coherent Transition Radiation (CTR) and Coherent Undulator Radiation (CUR) to generate THz radiation with an ultrashort electron bunch. Such high intensity THz sources allow the THz spectrum to be conducted easily with a THz interferometer and a Golay cell detector. Furthermore, the radiation spectrum carries information of the electron distribution which allows ultrashort electron bunch length measurements. For verifying correct measuring procedure during the CTR and CUR experiments, a conventional THz radiation generated by optical rectification from a ZnTe crystal has been performed. The produced THz pulse was sent into a Michelson interferometer which is designed for the autocorrelation of the intense, sub-mm and mm-wavelength, spatially-coherent radiation pulses. The THz spectrum can be further obtained from the interferogram by the Fourier transform process. In such way, the THz spectrum can be investigated if the result is satisfactory and can be applied on the THz CTR and CUR experiments for the next step.

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THPIK103

Six Months of Operation of the New RF Cavity System of SLRI

cavity, operation, storage-ring, status

4331

N. Juntong, Ch. Dhammatong, P. Sudmuang, N. Suradet
SLRI, Nakhon Ratchasima, Thailand

The new RF cavity system has been installed in the storage ring of SIAM Photon Source (SPS) since August 2016. The RF cavity was designed base on the MAX-IV laboratory capacitive loaded type cavity. The solid-state technology was implemented in the RF high power transmitter. The low-level RF system utilized the digital technology. The system has been successfully commissioned and run with a capability to compensate an energy lost from a full capacity run of insertion devices since August 2016. This paper summarizes the problems and actions of the new RF system and presents an overview of six months of operation of the new RF system in the storage ring of SPS.

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THPIK123

Magnetron Design for Amplitude Modulation

cavity, injection, cryomodule, vacuum

4389

M.L. Neubauer, A. Dudas, S.A. Kahn
Muons, Inc, Illinois, USA
R.A. Rimmer, H. Wang
JLab, Newport News, Virginia, USA

The amplitude modulation (AM) of a magnetron is accomplished by varying the magnetic field which changes the current to the anode and the output power of the injection locked magnetron. The purpose of the AM is to compensate for microphonics in super conducting cavities by maintaining a constant gradient. The frequency range for the microphones is below 200 Hz. At these frequencies, eddy currents are encountered in the magnetron anode that reduce the effectiveness of the varying magnetic field on the magnetron current. A novel anode design is described which minimizes eddy currents and a method for manufacturing this novel magnetron anode is presented

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THPVA039

Nanopositioning and Actuation in Extreme Environment Using Piezoelectric Multilayer Actuators and Motors

vacuum, diagnostics, operation, electron

4519

C. Mangeot
Noliac A/S, Kvistgaard, Denmark

Piezoelectric devices find numerous applications in Science projects, when precise and fast positioning is needed, particularly in harsh environment. This paper reviews some of the latest environmental tests performed on piezoelectric devices, illustrating how they enable higher performance or even new technical solutions. In the field of particle accelerators and instrumentation, two applications can be mentioned: the precise goniometer to be installed in the Large Hadron Collider (LHC) and active Lorentz force detuning compensation systems*. Multilayer actuators have been demonstrated over a wide range of temperatures, from cryogenic (4K) to 220°C, in UHV and under radiation. Other examples can be mentioned within the ITER project: the In-Vessel Viewing System (IVVS) and the Electron Cyclotron Emission (ECE) diagnostic**. For these applications, a piezo motor is needed. The Piezo Actuator Drive (PAD) was demonstrated at high temperature, UHV and submitted to high magnetic fields.
* P. Bosland et al.; 'Mechanical study of the Saclay Piezo Tuner PTS (Piezo Tunning System)', CARE-Note-2005-004-SRF
** G. Taylor et al.; 'Status of the design of the ITER ECE diagnostic', EC18, 2015

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THPVA068

General Design of ID Front Ends in the TPS

photon, vacuum, synchrotron, storage-ring

4601

C.K. Kuan, C.K. Chan, Y.T. Cheng, J. -Y. Chuang, Y.M. Hsiao, I.C. Sheng, C. Shueh, H.Y. Yan
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source is a 3 GeV, 3rd generation synchrotron radiation source at the NSRRC. Phase-I commissioning includes seven Insertion Device (ID) Front Ends which are built to transmit intense synchro-tron radiation generated by In-vacuum Undulators and Elliptically Polarizing Undulators in the storage ring to the Photon Beamline. The total power and power distri-bution on Front End components is calculated and ana-lysed and Finite Element Analysis is used to verify the thermal performance under high heat loads while Monte-Carlo methods are utilized to simulate the vacuum pres-sure distribution. All apertures of the components are the same to simplify and standardize the design of the Front Ends. This paper describes main design considerations, especially the high heat load and vacuum pressure distri-bution.

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THPVA072

Travelling Laser Focus System for the Particles Acceleration

laser, acceleration, emittance, photon

4613

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

We describe the result of the wake-fields calculation in a device for acceleration of particles in the micro-structures illuminated by the swept laser bust. Calculations carried with help of FlexPDE code.

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THPVA081

Radiation Tests of Aerospace Components at ELBE

electron, experiment, gun, detector

4641

Ch. Schneider, D. Bemmerer, P. Michel, D. Stach
HZDR, Dresden, Germany

The cw electron accelerator ELBE operates mainly in the beam energy range 6 to 32 MeV and beam current range 1μA to 1mA. For most experiments a thermionic gun is used as electron source. The cw electron pulse structure so as the pulse charge is realized by applying electrical pulses with specific amplitudes and frequencies on the grid of the gun. The standard cw operation frequency is 13 MHz but can be divided sequentially by the factor 2 down to 101 kHz. For very special pulse structures a so called single pulser module exist performing different patterns also with dark current suppression via a macro pulser gate. For evaluating the performance and hardness under irradiation of e.g. aerospace components much lower doses respectively currents lower than the μA range are required. Furthermore reproducible and stable doses in a specific area for consecutively radiation of samples are necessary. In the presentation the investigations and concepts used at ELBE for the irradiation of different aerospace components are described.

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THPVA091

Diagnostics Methods for the Medium Energy Proton Beam Extracted by the TOP IMPLART Linear Accelerator

proton, linac, detector, diagnostics

4673

M. Vadrucci, A. Ampollini, P. Nenzi, L. Picardi, C. Ronsivalle, E. Trinca
ENEA C.R. Frascati, Frascati (Roma), Italy
E. Cisbani, F. Ghio
ISS, Rome, Italy
M. Marinelli, G. Prestopino, G. Verona Rinati
INFN - Roma Tor Vergata, Roma, Italy
C. Placido
University of Rome La Sapienza, Rome, Italy

Funding: This material is based upon work supported by the Regione Lazio/Italy
The Italian TOP IMPLART project aims to develop the first proton linear accelerator for cancer radiotherapy. A 150MeV proton LINAC is under construction at the ENEA Frascati research center: currently the machine is composed by a 7MeV injector operating at 425MHz and four 3GHz SCDTL modules producing a proton beam of 35MeV. Operational procedures for irradiation of samples need careful measurements of average beam current, transverse distribution and pulse charge by different monitor types placed along the beam line. The injected current in the high frequency segment of the accelerator is measured by a Fast Current Transformer (FCT) at the entrance of the SCDTL modules and the pulsed current of the accelerated beam is measured by a second FCT, placed in air, at the exit. The output proton beam shape and intensity are measured by an integral ionization chamber, a double (XY) multistrip ionization chamber, a synthetic single crystal diamond detector and a Faraday cup. In this work, the results of these multiple diagnostic tools applied to different operating conditions of the machine are presented.

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THPVA097

Estimation and Measurements of Radiation Dose Distibution for the Radiation Test Area in J-PARC Main Ring

neutron, proton, photon, operation

4689

M.J. Shirakata
KEK, Ibaraki, Japan

The J-PARC main ring has a beam collimator system in the first straight section for the beam halo rejection. Though it makes a high radiation area in the ring which requires a serious maintenance scheme, a high radiation dose can be applied to the tests of radiation resistible devices. The radiation dose distribution was estimated by using PHITS code, and it was confirmed by dose meas-urements using RadMon, nanoDot OSL dosimeters with continuous monitoring of beam losses. The availability of the radiation test area in the accelerator ring is reported in this paper.

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THPVA113

Inverse Problem-Based Magnetic Characterization of Weekly Magnetic Alloys

dipole, background, luminosity, collider

4722

A. Parrella, M.P. Ramos
IT, Lisboa, Portugal
P. Arpaia, A. Liccardo
Naples University Federico II, Science and Technology Pole, Napoli, Italy
M.C.L. Buzio
CERN, Geneva, Switzerland

Understanding the magnetic properties of materials used in accelerator components is becoming more and more important. For example, in the upcoming LHC upgrade at CERN, the increasing luminosity will boost the radiation dose received by the accelerator magnet's coil and consequently decrease its lifespan. Hence, a radiation shield with relative permeability less than 1.005 is required. The goal of this research is to design and validate a new method for characterizing weekly magnetic materials, suitable to be used in quality control of series production. The proposed method is based on inverse analysis approach coupled with a finite-element model. A material with unknown permeability is inserted in the air gap of a dipole magnet and the consequent perturbations of the dipole background flux density are measured. The magnetic permeability is then identified through gray-box inverse modelling, based on a finite-element approach. The results have been used to predict the magnetic impact of the radiation shield and develop further research on this subject.

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THPVA137

A Monte Carlo Approach to Imaging and Dose Simulations in Realistic Phantoms Using Compact X-Ray Source

simulation, photon, electron, detector

4783

E. Skordis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
E. Skordis, V. Vlachoudis
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

X-ray emitters are amongst the most widely used tools in medicine. Based on compact electron beams, they are utilised for a range of applications, including medical imaging and cancer treatment. The optimisation of a specific X-ray source relies on detailed simulation studies into the achievable resolution and intensity distribution. Monte Carlo (MC) codes are widely used in the medical community for dose estimation to patients and the environment. They are also ideally suited for simulating 3D intensity distributions in realistic environments. This demands accurate and reliable physical models capable of handling all components of the expected radiation field. In this paper the capabilities of the FLUKA MC code to simulate complex X-ray sources are presented. Advanced phantoms, based on imported DICOM format, are used to evaluate the dose to relevant areas, including the patient, individual organs and the treatment room. It is also shown how they can provide a good basis to reproduce radiography images by scoring photon fluencies.

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THPVA139

Relative Insensitivity to Inhomogeneities on Very High Energy Electron Dose Distributions

electron, simulation, experiment, photon

4791

A. Lagzda, R.M. Jones
UMAN, Manchester, United Kingdom
D. Angal-Kalinin, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
K. Kirkby
The Christie NHS Foundation Trust, Manchester, United Kingdom

Funding: Science and Technology Facilities Council, United Kingdom Cockroft Institute, United Kingdom Christie Hospital, Manchester, United Kingdom
We investigated the effects of heterogeneous regions on dose deposition of very high-energy electrons (VHEE) using both Geant4 simulations and experiments performed at the CALIFES facility at CERN. Small air and acetal plastic (bone equivalent) cavities were embedded in a water phantom and irradiated with a 197 MeV electron beam. Experimentally determined transverse dose profiles were acquired using radiation sensitive EBT3 Gafchromic films embedded in the water phantom at various depths. EBT3 Gafchromic films were found to be a suitable dosimeter for relative dose dosimetry of VHEE beams. Simulated and measured results were found to be consistent with each other and the largest discrepancy was found to be no more than 5%. Dose profiles of VHEE beams were found to be relatively insensitive to embedded high and low density geometries.

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THPVA141

Non-Destructive Measurement of Electron Microbunch Separation

electron, laser, experiment, gun

4798

H. Zhang, G. Doucas, H. Harrison, I.V. Konoplev, A.J. Lancaster
JAI, Oxford, United Kingdom
A. Aryshev, M. Shevelev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

With the development of femtosecond lasers, the generation of micro-bunched beams directly from a photocathode becomes routine; however, the monitoring of the separation is still a challenge. We present the results of proof-of-principle experiments measuring the distance between two bunches via the amplitude modulation analysis of a monochromatic radiation signal. Good agreement with theoretical prediction is shown.

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FRXBB1

Novosibirsk Four-Orbit ERL With Three FELs

FEL, electron, undulator, gun

4836

N.A. Vinokurov, V.S. Arbuzov, K.N. Chernov, I.V. Davidyuk, O.I. Deichuli, E.N. Dementyev, B.A. Dovzhenko, Ya.V. Getmanov, Ya.I. Gorbachev, B.A. Knyazev, E.I. Kolobanov, A.A. Kondakov, V.R. Kozak, E.V. Kozyrev, S.A. Krutikhin, V.V. Kubarev, G.N. Kulipanov, E.A. Kuper, I.V. Kuptsov, G.Y. Kurkin, L.E. Medvedev, S.V. Motygin, V.N. Osipov, V.K. Ovchar, V.M. Petrov, A.M. Pilan, V.M. Popik, V.V. Repkov, T.V. Salikova, M.A. Scheglov, I.K. Sedlyarov, S.S. Serednyakov, O.A. Shevchenko, A.N. Skrinsky, S.V. Tararyshkin, V.G. Tcheskidov, A.G. Tribendis, P. Vobly, V. Volkov
BINP SB RAS, Novosibirsk, Russia
I.V. Davidyuk, Ya.V. Getmanov, B.A. Knyazev, E.V. Kozyrev, S.S. Serednyakov, N.A. Vinokurov
NSU, Novosibirsk, Russia
A.G. Tribendis
NSTU, Novosibirsk, Russia

The Novosibirsk FEL facility has three FELs, installed on the first, second and fourth orbits of the ERL. The first FEL covers the wavelength range of 90 - 240 mkm at an average radiation power of up to 0.5 kW with a pulse repetition rate of 5.6 or 11.2 MHz and a peak power of up to 1 MW. The second FEL operates in the range of 40 - 80 mkm at an average radiation power of up to 0.5 kW with a pulse repetition rate of 7.5 MHz and a peak power of about 1 MW. These two FELs are the world's most powerful (in terms of average power) sources of coherent narrow-band (less than 1%) radiation in their wavelength ranges. The third FEL was commissioned in 2015 to cover the wavelength range of 5 - 20 mkm. The Novosibirsk ERL is the first and the only multiturn ERL in the world. Its peculiar features include the normal-conductive 180 MHz accelerating system, the DC electron gun with the grid thermionic cathode, three operation modes of the magnetic system, and a rather compact (6×40 m2) design. The facility has been operating for users of terahertz radiation since 2004.

Slides FRXBB1 [51.485 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-FRXBB1

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