IPAC2016 - List of Keywords (synchrotron-radiation)

Paper	Title	Other Keywords	Page
MOPMB014	Simultaneous Detection of Longitudinal and Transverse Bunch Signals at ANKA	synchrotron, detector, radiation, timing	109
	B. Kehrer, E. Blomley, M. Brosi, E. Bründermann, N. Hiller, A.-S. Müller, M.J. Nasse, M. Schedler, M. Schuh, P. Schönfeldt, P. Schütze, N.J. Smale, J.L. Steinmann KIT, Karlsruhe, Germany
	Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 and by the BMBF under contract number 05K13VKA. The ANKA storage ring offers different operation modes including the short-bunch mode with bunch lengths tuned down to a few picoseconds. This can lead to the occurrence of micro-bunching instabilities coupled to the emission of coherent synchrotron radiation (CSR) in so-called 'bursts'. To study this CSR instability we use several turn-by-turn enabled detector systems to synchronously measure both the THz signal as well as bunch profiles. The different detectors are placed at different locations around the storage ring. Here we discuss the experimental setup and calibration of the various systems' synchronisation.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB014
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MOPMB016	Single-Shot Spectral Analysis of Synchrotron Radiation in THz Regime at ANKA	detector, radiation, synchrotron, bunching	115
	A. Schmid, M. Brosi, E. Bründermann, K.S. Ilin, B. Kehrer, K. Kuzmin, A.-S. Müller, J. Raasch, M. Schuh, P. Schönfeldt, M. Siegel, J.L. Steinmann, S. Wuensch KIT, Karlsruhe, Germany S.A. Kuznetsov NSU, Novosibirsk, Russia
	Funding: This work was supported by BMBF contract number 05K13VK4 and the Ministry of Education and Sci- ence of the Russian Federation (State Assignment Contract No. 3002). Micro-bunching instabilities limit the longitudinal compression of bunches in an electron storage ring. They create substructures on the bunch profile of some hundred micrometer size leading to coherently emitted synchrotron radiation in the THz range. To detect the changing THz spectrum, single-shot bunch-by-bunch and turn-by-turn measurements are necessary. We present recent experiments at ANKA where the spectral information is extracted by simultaneous detection with several narrowband THz detectors, each of them sensitive in a different frequency range.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB016
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MOPMB036	Beam Profile Measurement Using Kirkpatrick Baez Mirror Optics at Shanghai Synchrotron Radiation Facility	synchrotron, radiation, optics, diagnostics	167
	D.C. Zhu, J.S. Cao, Y.F. Sui, J.H. Yue IHEP, Beijing, People's Republic of China J. Chen SINAP, Shanghai, People's Republic of China
	For the third-generation light sources, the vertical emit-tance of a few pico-meter-radians which can be achieved with good coupling correction close to 0.1%, will lead to very small beam size. Several microns vertical beam sizes measurement has presented challenges for diagnostic capability in this region. A few techniques have been developed to make a precise measurement, such as visible light interferometer, x-ray imaging using Fresnel zone plates, compound refractive lenses or pinhole camera. In this paper, an x-ray reflective optics method based on the Kirkpatrick'Baez mirrors will be emphasis on discussed. The K-B mirror system will be installed and tested in SSRF to obtain the vertical beam size close to 20 microns, which is expected to be used for several microns vertical beam size measurement in the future light source named HEPS (High Energy Photon Source) in China.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB036
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MOPMB048	Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring	experiment, injection, storage-ring, electron	199
	L.W. Duan, Y.B. Leng, R.X. Yuan SINAP, Shanghai, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB048
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MOPMB050	Design of Ultra-wideband Amplifier in RF Front End for Bunch-by-bunch Measurement	power-supply, simulation, impedance, experiment	205
	Y. Yang, Y.B. Leng, Y.B. Yan SSRF, Shanghai, People's Republic of China
	RF front end is one of the key technologies in beam diagnosis, especially in bunch-by-bunch measurement at storage ring. This paper gives the design of ultra-wideband amplifier in RF front end for bunch-by-bunch measurement at SSRF. Simulation have been done to verify the performance of this design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB050
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MOPMR030	Performance of the Upgraded Synchrotron Radiation Diagnostics at the LHC	radiation, extraction, synchrotron, diagnostics	306
	G. Trad, E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo CERN, Geneva, Switzerland T.M. Mitsuhashi KEK, Ibaraki, Japan
	During the LHC long shut down in 2014, the transverse beam size diagnostics based on synchrotron radiation was upgraded in order to cope with the increase of the LHC beam energy to 6.5 TeV. The wavelength used for imaging was shifted to near ultra-violet to reduce the contribution of diffraction to the system resolution, while in parallel, a new diagnostic system based on double slit interferometry was installed to measure the beam size by studying the spatial coherence of the emitted synchrotron radiation. This method has never been implemented before in a proton machine. A Hartmann mask was also installed to identify possible wavefront distortions that could affect the system accuracy. This paper will focus on the comparison of visible and the near ultra-violet imaging and on the first experience with interferometry.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR030
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MOPMR032	Measurement of Beam Size with a SR Interferometer in TPS	radiation, synchrotron, shielding, monitoring	313
	M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, C.W. Tsai, T.C. Tseng, H.S. Wang NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) has operated since 2015. An optical diagnostic beamline is constructed in section 40 of TPS for the diagnosis of the properties of the electron beam. One instrument at this beamline is a synchrotron radiation interferometer (SRI), which is operated to monitor the beam size. In this paper, we present the beamline structure and recent results of measurement with the SR interferometer.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR032
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MOPMR034	Precise Betastron Tune Measurement in TPS Storage Ring	betatron, storage-ring, simulation, radiation	319
	C.H. Chen, C.H. Chang, J.Y. Chen, M.-S. Chiu, S. Fann, C.H. Huang, T.Y. Lee, C.C. Liang, Y.-C. Liu, F.H. Tseng NSRRC, Hsinchu, Taiwan
	To acquire precise beam orbits from beam position monitors (BPMs) in storage ring is one of the most significant diagnosis to measure beam parameters. However, the precise spectrum analyses from BPM data acquisitions such as betatron tune, dynamics aperture and frequency map '..etc. that are depended on more accurate discrete Fourier transform (DFT) or the fast Fourier transform (FFT). A method of the fast Fourier transform correction (FFTc) was employed for the more accurate spectrum measurement in Taiwan Photon Source (TPS). We perform the accuracy and error analyses of this method from some spectral lines in two window functions. And the precise spectrum for betatron tune measurements and related results will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR034
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MOPMR036	Using a Single Shot Spectrometer to Determine the Spectral Characteristics of the Beam as a Result of Micro-bunching Instabilities	detector, radiation, synchrotron, storage-ring	327
	A. Finn, P. Karataev JAI, Egham, Surrey, United Kingdom P. Karataev Royal Holloway, University of London, Surrey, United Kingdom G. Rehm DLS, Oxfordshire, United Kingdom
	A single shot spectrometer has been designed and is in operation at the Diamond Light Source (DLS). It is an array of eight Schottky barrier diodes (SBDs) each with a distinct frequency band covering 33-1000 GHz. The aim of the spectrometer is to observe the bursts of coherent synchrotron radiation (CSR) as a result of micro-bunching instabilities (MBI) and stable low alpha modes, where alpha is the momentum compaction factor. In this case, the bursts of CSR occur with wavelengths in the mm regime. SBDs are often implemented as detectors in the millimetre wavelength range and benefit from low noise, excellent sensitivity and ultra-fast responses. The eight SBDs have been individually characterised thus making the results obtained comparable to simulations. Here we present, an analysis of the data obtained via the spectrometer in particular, the bursting nature and spectral characteristics of a sample of beam modes at DLS. Furthermore, the results obtained can be used to confirm simulations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR036
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MOPMR052	Single-shot Bunch-by-Bunch Horizontal Beam Size Measurements using a Gated Camera at CesrTA	electron, positron, ion, vacuum	364
	S. Wang Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA R. Holtzapple CalPoly, San Luis Obispo, California, USA
	Funding: Work supported by NSF NSF PHY-1416318, PHYS-1068662, PHYS-1535696 A visible-light beam size monitor has been built and commissioned to measure transverse beam profiles at CESR-TA. In order to eliminate beam jitter and to study bunch-by-bunch beam dynamics, a fast-gating camera has been utilized to measure single bunch transverse beam profiles. The minimum camera gate width is ~ 3ns which allows us to resolve single bunch beam dynamics along a CesrTA bunch train. Using single bunch interferometry at different bunch currents, we found that the horizontal beam sizes measured by gated camera are consistently less than those measured by a conventional CCD camera, demonstrating the elimination of turn-by-turn beam jitter with single shot capability. By stepping the camera trigger delay, we collected transverse beam profile images from each bunch in a 14ns-spacing 30-bunch train. The horizontal motion of each bunch as well as the horizontal beam size increases dramatically along an electron train but not along positron bunch trains under the same machine condition. The difference in single bunch horizontal dynamics may be a signature for the difference between electron cloud build-up for positron bunch trains versus ions present for electron bunch trains. S.T. Wang, D.L. Rubin, J. Conway, M. Palmer, D. Hartill, R. Campbell, R. Holtzapple, NIMA, 703 (2013) 80
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR052
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MOPMR054	Double-slit Interferometer Measurements at SPEAR3	electron, synchrotron, radiation, optics	368
	C.L. Li, W.J. Zhang East China University of Science and Technology, Shanghai, People's Republic of China M.J. Boland SLSA, Clayton, Australia W.J. Corbett, M. Grinberg SLAC, Menlo Park, California, USA T.M. Mitsuhashi KEK, Ibaraki, Japan Y.H. Xu DongHua University, Songjiang, People's Republic of China W.J. Zhang University of Saskatchewan, Saskatoon, Canada
	The resolution of a conventional telescope used to image visible-light synchrotron radiation is often limited by diffraction effects. To improve resolution, the double-slit interferometer method was developed at KEK and has since become popular around the world. Based on the Van Cittert-Zernike theorem relating transverse source profile to transverse spatial coherence, the particle beam size can be inferred by recording fringe contrast as a function of interferometer slit separation. In this paper, we describe the SPEAR3 double-slit interferometer, develop a theoretical framework for the interferometer and provide experimental results. Of note the double-slit system is 'rotated' about the beam axis to map the dependence of photon beam coherence on angle.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR054
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MOPOR046	Studies on Depolarization by Synchrotron Radiation using Elegant Particle Tracking	synchrotron, radiation, polarization, resonance	695
	J.F. Schmidt, W. Hillert ELSA, Bonn, Germany
	Funding: BMBF Spin dynamics in circular electron accelerators are significantly influenced by the emission of synchrotron light. In storage rings, Sokolov-Ternov polarization build-up and radiative depolarization have crucial impact on equilibrium polarization. On shorter timescales, as in damping rings or synchrotrons with fast energy ramp, the temporal development of polarization depends on spin decoherence caused by stochastic momentum changes. Thus, especially longitudinal beam dynamics affect depolarization. This contribution presents the implementation of particle tracking with synchrotron radiation from Elegant in an in-house developed spin tracking code. Exemplary results on depolarization including synchrotron radiation are shown.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR046
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TUYA01	BEPCII Performance and Beam Dynamics Studies on Luminosity	luminosity, lattice, radiation, synchrotron	1014
	C.H. Yu, Z. Duan, S. Gu, Y.Y. Guo, X.Y. Huang, D. Ji, H.F. Ji, Y. Jiao, Zh.C. Liu, Y.M. Peng, Q. Qin, Y.S. Sun, S.K. Tian, J.Q. Wang, N. Wang, X.H. Wang, Y. Wei, X.M. Wen, J. Wu, J. Xing, G. Xu, Y. Yue, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China
	The upgrade of the Beijing Electron Positron Collider, BEPCII, is now in a good performance for both high energy physics and synchrotron radiation experiments. The luminosity at the design energy of 1.89 GeV reached the design value 1.0*10³³/cm²/s¹ recently. A lot of work, including accelerator physics study and technical progress, has been done for the luminosity enhancement, not only at the design energy, but all the energy region run for HEP experiments from 1.0 to 2.3 GeV. The performance of BEPCII and the process of luminosity enhancement will be described in detail.
	Slides TUYA01 [5.801 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUYA01
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TUOAB02	Conditions for CSR Microbunching Gain Suppression	dipole, emittance, lattice, synchrotron	1057
	C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA S. Di Mitri Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy D. Douglas, R. Li, C. Tennant JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport arcs, may result in phase space degradation. On one hand, the CSR can perturb electron transverse motion in dispersive regions along the beamline, causing emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching gain enhancement. For transport arcs, several schemes have been proposed* to suppress the CSR-induced emittance growth. Similarly, several scenarios have been introduced** to suppress CSR-induced microbunching gain, which however mostly aim for linac-based machines. In this paper we try to provide sufficient conditions for suppression of CSR-induced microbunching gain along a transport arc, analogous to. Several example lattices are presented, with the relevant microbunching analyses carried out by our semi-analytical Vlasov solver*. The simulation results show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. We expect this analysis can shed light on lattice design approach that could suppress the CSR-induced microbunching gain. D.Douglas et al, JLAB-ACP-14-1751, S.DiMitri et al, PRL (2013), R.Hajima, NIMA (2004), Y.Jiao et al, PRSTAB (2014) Z.Huang et al, PRSTAB (2004), Saldin et al, NIMA (2004) *C.Tsai et al, FEL'15
	Slides TUOAB02 [6.484 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOAB02
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TUPMB012	Optimization of the Field Integrals of Two Small Gap IDs for CLS	multipole, wiggler, undulator, vacuum	1133
	M.F. Qian, Y.Z. He, H.F. Wang, W. Zhang, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	An in-vacuum undulator and an in-vacuum wiggler have been developed for CLS at SSRF recently. The period lengths of the undulator and the wiggler are 20mm and 80mm respectively. Both IDs have the minimum gap of 5.2mm. The field integrals were measured for each magnet block with two poles and were sorted in-situ as they were installed on to the girders. Finally the field integrals of the undulator and the wiggler were shimmed by using the 'Magic Fingers' at the ends with a special algorithm. This paper reports the procedure and the results of the measurement and the optimization for the field integrals.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB012
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TUPOR006	Systematic Studies of Short Bunch-Length Bursting at ANKA	radiation, synchrotron, shielding, electron	1662
	M. Brosi, E. Blomley, E. Bründermann, N. Hiller, B. Kehrer, A.-S. Müller, M. Schedler, M. Schuh, P. Schönfeldt, J.L. Steinmann KIT, Karlsruhe, Germany
	Funding: Supported by the German Federal Ministry of Education and Research (05K13VKA), the Helmholtz Association (VH-NG-320) and by the Helmholtz International Research School for Teratronics (HIRST). At ANKA, the Karlsruhe synchrotron radiation source, the so called short bunch-length operation mode allows the reduction of the bunch length down to a few picoseconds. The micro-bunching instability resulting from the high degree of longitudinal compression leads to fluctuations in the emitted intensity in the THz regime, referred to as bursting. For extremely compressed bunches at ANKA bursting also occurs, in a certain current range, below the main bursting threshold. This contribution shows measurements of this short bunch-length bursting and makes first comparisons with theory.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR006
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TUPOR020	Combination of Density and Energy Modulation in Microbunching Analysis	electron, collective-effects, radiation, synchrotron	1703
	C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA R. Li JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Microbunching instability (MBI) has been one of the most challenging issues in the transport of high-brightness electron beams for modern recirculating or energy recovery linac machines. Recently we have developed and implemented a Vlasov solver* to calculate microbunching gain for an arbitrary beamline lattice design, based on the extension of early theoretical formulation for the microbunching amplification from an initial density perturbation to the final density modulation. For more thorough analyses, in addition to the case of (initial) density to (final) density amplification, we in this paper extend the previous formulation to more general cases, including energy-to-density, density-to-energy and energy-to-energy amplifications for a recirculation machine. Such semi-analytical formulae are then incorporated into our Vlasov solver, and reasonable agreement is obtained when the semi-analytical results are benchmarked with particle tracking simulation using ELEGANT. C.Y. Tsai et al, FEL'15 S. Heifets et al, PRSTAB 5, 064401 (2002), Z. Huang and K. Kim, PRSTAB 5, 074401 (2002), M. Vneturini, PRSTAB 10, 104401 (2007) * M. Borland, APS LS-287, 2000
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOR020
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WEOAA03	Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III	undulator, radiation, experiment, synchrotron	2036
	M. Hosaka Nagoya University, Nagoya, Japan M. Katoh, N.S. Mirian UVSOR, Okazaki, Japan T. Konomi, N. Yamamoto KEK, Ibaraki, Japan K. Kuroda ISSP, Kashiwa-shi, Japan K. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY and UVSOR-III. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation. S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008) J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013) * e.g. S. Sasaki et al., presented in SRI2015 (2015)
	Slides WEOAA03 [11.023 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA03
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WEPMW025	Optimizing the Design of Linear Non-scaling Fixed Field Alternating Gradient Arcs for the Electron Rings of eRHIC	radiation, synchrotron, lattice, electron	2475
	J.S. Berg BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. I describe a process for producing optimal linear non-scaling fixed field alternating gradient (FFAG) arc designs for the electron rings of eRHIC, an electron-ion collider in the RHIC tunnel at Brookhaven National Laboratory. The electrons are accelerated in two FFAG rings (low and high energy), which in addition to the arcs optimized here, contain straight sections, splitter/combiner sections, and a linac shared between the rings. The optimization process I use has two layers, an inner one meeting constraints and an outer optimization that minimizes a target function. The target function is an approximation to the FFAG arc cost, for which I give the function used and the basis for that choice. While reducing synchrotron radiation is important, I show that optimizing for synchrotron radiation alone leads to significant cost an performance penalties for the rest of the machine design for very little reduction in synchrotron radiation. I describe important constraints on the design, in particular minimum drift lengths, maximum and minimum tunes, and clearance from the beam to the beam pipe. Finally, I present possible eRHIC FFAG parameters resulting from this optimization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW025
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WEPMW044	Start-to-End Simulation of eRHIC ERL	linac, electron, simulation, emittance	2535
	Y. Hao, S.J. Brooks, Y.C. Jing, F. Méot, V. Ptitsyn, D. Trbojevic, N. Tsoupas BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The ERL-ring eRHIC adopts the electron accelerator design of a multi-pass energy recovery linac (ERL), with fixed field alternating gradient (FFAG) recirculating passes. To ensure the beam quality in the accelerating and decelerating stage and the energy recovery efficiency, detailed start-to-end simulation is required to evaluate the various beam dynamics effects, such as synchrotron radiation, wake fields, coherent synchrotron radiation. In this paper, we present the eRHIC ERL start-to-end simulation strategy with various simulation codes and the current status.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMW044
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WEPMY042	Effective Cycling and Ramping	power-supply, TANGO, synchrotron, device-server	2651
	Ł. Żytniak, L.J. Dudek, P.P. Goryl, A. Kisiel, W.T. Kitka, A.I. Wawrzyniak Solaris, Kraków, Poland P.J. Bell, V.H. Hardion, D.P. Spruce MAX IV Laboratory, Lund University, Lund, Sweden G. Gaio Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The National Synchrotron Radiation Centre Solaris, Kraków, Poland has been successfully built in collaboration with several institutes and organizations. The MAX IV Laboratory, Lund, Sweden and Elettra, Trieste, Italy, are the most important synchrotron partners. Solaris has built as an adaptation of MAX-IV 1.5 GeV ring and linear accelerator based on the same components as the ones of MAX-IV, therefore the device server for the magnet circuit has been developed by MAX-IV. Ramping was included in expert consultancy services contract won by Elettra. Solving problem with the power supplies stability and thanks to usage snapshots as steps for ramping it was possible to ramp the beam without losing current linearly.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPMY042
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WEPOR023	Radiation Shielding Considerations for CEPC-SPPC	radiation, shielding, synchrotron, monitoring	2722
	Z.J. Ma, Y.D. Ding, N. Li, Q.B. Wang, M.Y. Yan, Q.J. Zhang IHEP, Beijing, People's Republic of China
	A planned project CEPC-SPPC is under-researched by IHEP, CAS, China. Due to its big circumference and high energy, the radiation shielding issues should be treated more serious than ever whether for the machine itself or the worker and the public. In this paper, we briefly introduce the configurations and parameters of the machine, the tools and principle used in the radiation shielding design, and discuss the preliminary result for the shielding of main tunnel and the synchrotron radia-tion. Some radiation protection issues are listed to be resolved next. All the aspects presented should be dis-cussed and verified, any other unmentioned radiation protection problems will be excavated in the future. CEPC: Circular Electron-Positron Collider SPPC: Super Proton-Proton Collider IHEP: Institute of High Energy Physics CAS: Chinese Academy of Sciences
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR023
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WEPOW015	Influence of Filling Pattern Structure on Synchrotron Radiation Spectrum at ANKA	synchrotron, radiation, storage-ring, detector	2855
	J.L. Steinmann, E. Blomley, M. Brosi, E. Bründermann, C.M. Caselle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, M. Siegel KIT, Karlsruhe, Germany
	Funding: This work is supported by the Helmholtz International School for Teratronics (HIRST) We present the effects of the filling pattern structure in multi-bunch mode on the beam spectrum. This effects can be seen by all detectors whose resolution is better than the RF frequency, ranging from stripline and Schottky measurements to high resolution synchrotron radiation measurements. Our heterodyne measurements of the emitted coherent synchrotron radiation at 270 GHz reveal discrete frequency harmonics around the 100 000th revolution harmonic of ANKA, the synchrotron radiation facility in Karlsruhe, Germany. Significant effects of bunch spacing, gaps between bunch trains and variations in individual bunch currents on the emitted CSR spectrum are described by theory and supported by observations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW015
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WEPOW023	Present Status of Accelerators in Aichi Synchrotron Radiation Center	synchrotron, radiation, storage-ring, injection	2877
	Y. Takashima, M. Hosaka, A. Mano Nagoya University, Nagoya, Japan Y. Hori, N. Yamamoto KEK, Ibaraki, Japan M. Katoh UVSOR, Okazaki, Japan S. Koda SAGA, Tosu, Japan S. Sasaki JASRI/SPring-8, Hyogo, Japan T. Takano Hitachi Ltd., Ibaraki-ken, Japan
	Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW023
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WEPOY004	Integrated Green Function for Charged Particle moving along Bending Orbit	radiation, synchrotron, simulation, collider	2997
	K. Ohmi, S. Chen KEK, Ibaraki, Japan H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	Electro-magnetic field for moving charged particle is given by Liennard-Wiechert potential. The field contains high frequency component corresponding to synchrotron light, ω=3cγ³/(2ρ). The frequency is too high to study beam behavior generally. Green function integrated over beam distribution and/or over in a region σ_x/n_x× σ_y/n_y× σ_z/n_z (n_xyz ∼ 10) is useful to study instability and emittance growth of the beam. The green function is regarded as the wake field for coherent synchrotron radiation in three dimension space.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY004
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WEPOY060	YACS - Progression Towards Isoparametric 2.5D Finite Elements	cavity, software, radiation, experiment	3135
	B.D. Isbarn, B. Riemann, M. Sommer, T. Weis DELTA, Dortmund, Germany
	Funding: Work supported by the BMBF under contract no. 05K13PEB. YACS is a 2.5D finite element method solver capable of solving for the full 3D eigenfrequency spectra of resonant axisymmetric structures while reducing the computational problem to a 2D rotation plane. Prior studies and benchmarks, comparing YACS to well known commercial 3D and 2D applications, already demonstrated its capabilities of performing fast optimizations of geometries, due to its minimal computational overhead. However, because of the first order elements and basis functions used for approximation of the domain and field, this solving speed advantage vastly diminishes when targeting higher accuracies. In order to circumvent these issues, YACS was upgraded to support arbitrary order basis functions and curved meshes, leading to, but not limited to, isoparametric finite elements. This led to distinct performance and convergence improvements, especially when considering curved geometries, ideally representable by a polynomial mapping, e.g. when choosing a cavity geometry parametrization based on splines.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY060
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THPMB025	The Effect of Magnetic Field on the Secondary Electron Yield in the Ultra-High Vacuum Environment	electron, gun, permanent-magnet, vacuum	3281
	J. Wang, Y. Wang, W. Wei, Y.H. Xu, B. Zhang, T. Zhang, Y.X. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	A secondary electron emission measurement system has been designed and used to study the secondary electron emission (SEE) of different materials with an independently adjustable energy of 50 eV to 5 keV at National Synchrotron Radiation Laboratory. Here, we obtained the characteristics of the SEE yield from Pd film coatings, under the condition of magnetic field and without magnetic field. Then it was analysed that the effect of magnetic field on the secondary electron yield in the ultra-high vacuum environment. The results show that magnetic field shielding is critical to avoid the influence of magnetic field during secondary electron yield (SEY) measurements.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMB025
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THPMB026	Research on Low Secondary Electron Yield Materials for Future Accelerators	electron, vacuum, laser, proton	3284
	J. Wang, Y. Wang, W. Wei, Y.H. Xu, B. Zhang, T. Zhang, Y.X. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	For future accelerators, such as SPPC (SEYmax <1.2), the build-up of electron cloud generated in the beam pipes considerably affect the stability of particle beams. Therefore, it is critical to look for steady and low secondary electron yield (SEY) material for future high intensity accelerators.
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THPMB034	Short Bunch Operation Mode Development at the Synchrotron Radiation Source Siberia-2	operation, optics, emittance, synchrotron	3305
	Y.A. Fomin, V. Korchuganov, S.I. Tomin, A.G. Valentinov NRC, Moscow, Russia
	Decrease of the electron bunch length gives rise to coherent synchrotron radiation in the THz spectral region. Also, the short photons pulse could provide an option for time-resolved processes studies. Currently the possibility to operate with short electron bunch of the synchrotron radiation source Siberia-2 is under consideration for this purpose. In the report the techniques of electron bunch shortening are described as well as the requirements are given for the parameters of the electron bunch and lattice. The authors present a modified lattice for the synchrotron radiation source Siberia-2 with low momentum compaction factor and the results of the beam dynamics studies.
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THPMR045	CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization	luminosity, lattice, sextupole, radiation	3500
	F. Plassard, D. Schulte, R. Tomás CERN, Geneva, Switzerland P. Bambade LAL, Orsay, France
	This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown.
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THPMY011	Chamber Upgrade for EPU48 in TPS	vacuum, storage-ring, synchrotron, radiation	3676
	I.C. Sheng, C.K. Chan, C.-C. Chang, C.M. Cheng, Y.T. Cheng, J. -Y. Chuang, Y.M. Hsiao, Y.T. Huang, C. Shueh, L.H. Wu, I.C. Yang NSRRC, Hsinchu, Taiwan
	Due to high total power and power density in Taiwan Photon Source (TPS) of EPU48 (Elliptical Polarized Undulator) in double minimum sector, we fabricate a new Aluminum vacuum chamber to increase sufficient room for synchrotron radiation to pass through without damage the storage ring chamber. A new method of in-site replacement of bending chamber is also presented, the result of this replacement procedure shows that it is very cost-effective as well as good UHV vacuum quality.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY011
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THPMY014	Study of the Non-evaporable Ti-Zr-V Films Grown on Different Materials	vacuum, electron, experiment, booster	3682
	L.H. Wu, C.M. Cheng, Y.T. Huang, S.Y. Perng, I.C. Sheng, C. Shueh NSRRC, Hsinchu, Taiwan
	The non-evaporable (NEG) Ti-Zr-V films were coated on the different vacuum-chamber materials, including the extruded aluminum samples (Al), the extruded seamless stainless steel samples (S.S.), CuCrZr alloys, and oxygen-free copper (OFC) plates. The NEG films were fabricated by using the direct current (DC) sputtering method. The secondary electron microscopy images showed that the morphology of NEG films was different on these various substrates. The thermal analysis (TA) presented that exothermic reaction happened by heating the samples.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY014
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THPMY034	Power Saving Status at NSRRC	controls, radiation, synchrotron, operation	3734
	J.-C. Chang, W.S. Chan, Y.C. Chang, C.S. Chen, Y.F. Chiu, Y.-C. Chung, K.C. Kuo, M.T. Lee, Y.-C. Lin, C.Y. Liu, Y.-H. Liu, Z.-D. Tsai, T.-S. Ueng, J.P. Wang NSRRC, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC), Taiwan currently operates two synchrotrons, the Taiwan Light Source (TLS) and Taiwan Photon Source (TPS). The former one has been operated for more than 22 years, while the latter is in commissioning phase. We target of the beam current on 500 mA. Thus, the power consumption increases higher than ever. Currently, the contract power capacities of the TLS and TPS with the Taiwan Power Company (TPC) are 5.5MW and 7.5MW, respectively. The ultimate power consumption of the TPS is estimated about 12.5MW. To cope with increasing power requirement, we have conducting several power saving schemes for years. This paper presents our latest power schemes, which include installation of power saving fan for the cooling tower, adjustment of supply air temperature according to the atmosphere enthalpy, replacement of old air conditioning unit (AHU), power consumption control by the operation of chillers, and power factor improvement.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMY034
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THPOY023	Upgrade of NSLS-II Active Interlock System	storage-ring, operation, synchrotron, radiation	4140
	S. Seletskiy, J. Choi, K. Ha, R.M. Smith BNL, Upton, Long Island, New York, USA
	The NSLS-II Storage Ring is protected from possible damage from synchrotron radiation by a dedicated active interlock system (AIS). The AIS monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope. The one year worth of the AIS operation showed that there is a number of erroneous machine trips associated with the AIS. In this paper we describe an upgrade of the AIS that allowed us to get rid of the Storage Ring faults and improved the overall NSLS-II reliability.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY023
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THPOY047	Comprehensive Approach to Synchrotron Radiation Protection of NSLS-II	radiation, synchrotron, electron, undulator	4211
	S. Seletskiy, T.V. Shaftan BNL, Upton, Long Island, New York, USA
	To protect the NSLS-II Storage Ring components from possible damage from synchrotron radiation produced by insertion devices (IDs) and bending magnets (BMs) the Active Interlock System (AIS) keeps electron beam within the AI safe envelope (AIE) in the transverse phase space. The NSLS-II beamlines (BLs) and frontends (FEs) are designed under assumption that above certain safe beam current the ID synchrotron radiation (IDSR) fan is produced by the interlocked e-beam. In this paper we describe a new approach to defining the AIS parameters and settings, which significantly simplifies the process of the FE and BL design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOY047
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Paper

Title

Other Keywords

Page

MOPMB014

Simultaneous Detection of Longitudinal and Transverse Bunch Signals at ANKA

synchrotron, detector, radiation, timing

109

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

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 and by the BMBF under contract number 05K13VKA.
The ANKA storage ring offers different operation modes including the short-bunch mode with bunch lengths tuned down to a few picoseconds. This can lead to the occurrence of micro-bunching instabilities coupled to the emission of coherent synchrotron radiation (CSR) in so-called 'bursts'. To study this CSR instability we use several turn-by-turn enabled detector systems to synchronously measure both the THz signal as well as bunch profiles. The different detectors are placed at different locations around the storage ring. Here we discuss the experimental setup and calibration of the various systems' synchronisation.

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MOPMB016

Single-Shot Spectral Analysis of Synchrotron Radiation in THz Regime at ANKA

detector, radiation, synchrotron, bunching

115

A. Schmid, M. Brosi, E. Bründermann, K.S. Ilin, B. Kehrer, K. Kuzmin, A.-S. Müller, J. Raasch, M. Schuh, P. Schönfeldt, M. Siegel, J.L. Steinmann, S. Wuensch
KIT, Karlsruhe, Germany
S.A. Kuznetsov
NSU, Novosibirsk, Russia

Funding: This work was supported by BMBF contract number 05K13VK4 and the Ministry of Education and Sci- ence of the Russian Federation (State Assignment Contract No. 3002).
Micro-bunching instabilities limit the longitudinal compression of bunches in an electron storage ring. They create substructures on the bunch profile of some hundred micrometer size leading to coherently emitted synchrotron radiation in the THz range. To detect the changing THz spectrum, single-shot bunch-by-bunch and turn-by-turn measurements are necessary. We present recent experiments at ANKA where the spectral information is extracted by simultaneous detection with several narrowband THz detectors, each of them sensitive in a different frequency range.

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MOPMB036

Beam Profile Measurement Using Kirkpatrick Baez Mirror Optics at Shanghai Synchrotron Radiation Facility

synchrotron, radiation, optics, diagnostics

167

D.C. Zhu, J.S. Cao, Y.F. Sui, J.H. Yue
IHEP, Beijing, People's Republic of China
J. Chen
SINAP, Shanghai, People's Republic of China

For the third-generation light sources, the vertical emit-tance of a few pico-meter-radians which can be achieved with good coupling correction close to 0.1%, will lead to very small beam size. Several microns vertical beam sizes measurement has presented challenges for diagnostic capability in this region. A few techniques have been developed to make a precise measurement, such as visible light interferometer, x-ray imaging using Fresnel zone plates, compound refractive lenses or pinhole camera. In this paper, an x-ray reflective optics method based on the Kirkpatrick'Baez mirrors will be emphasis on discussed. The K-B mirror system will be installed and tested in SSRF to obtain the vertical beam size close to 20 microns, which is expected to be used for several microns vertical beam size measurement in the future light source named HEPS (High Energy Photon Source) in China.

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MOPMB048

Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring

experiment, injection, storage-ring, electron

199

L.W. Duan, Y.B. Leng, R.X. Yuan
SINAP, Shanghai, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.

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MOPMB050

Design of Ultra-wideband Amplifier in RF Front End for Bunch-by-bunch Measurement

power-supply, simulation, impedance, experiment

205

Y. Yang, Y.B. Leng, Y.B. Yan
SSRF, Shanghai, People's Republic of China

RF front end is one of the key technologies in beam diagnosis, especially in bunch-by-bunch measurement at storage ring. This paper gives the design of ultra-wideband amplifier in RF front end for bunch-by-bunch measurement at SSRF. Simulation have been done to verify the performance of this design.

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MOPMR030

Performance of the Upgraded Synchrotron Radiation Diagnostics at the LHC

radiation, extraction, synchrotron, diagnostics

306

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

During the LHC long shut down in 2014, the transverse beam size diagnostics based on synchrotron radiation was upgraded in order to cope with the increase of the LHC beam energy to 6.5 TeV. The wavelength used for imaging was shifted to near ultra-violet to reduce the contribution of diffraction to the system resolution, while in parallel, a new diagnostic system based on double slit interferometry was installed to measure the beam size by studying the spatial coherence of the emitted synchrotron radiation. This method has never been implemented before in a proton machine. A Hartmann mask was also installed to identify possible wavefront distortions that could affect the system accuracy. This paper will focus on the comparison of visible and the near ultra-violet imaging and on the first experience with interferometry.

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MOPMR032

Measurement of Beam Size with a SR Interferometer in TPS

radiation, synchrotron, shielding, monitoring

313

M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, S.Y. Perng, C.W. Tsai, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) has operated since 2015. An optical diagnostic beamline is constructed in section 40 of TPS for the diagnosis of the properties of the electron beam. One instrument at this beamline is a synchrotron radiation interferometer (SRI), which is operated to monitor the beam size. In this paper, we present the beamline structure and recent results of measurement with the SR interferometer.

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MOPMR034

Precise Betastron Tune Measurement in TPS Storage Ring

betatron, storage-ring, simulation, radiation

319

C.H. Chen, C.H. Chang, J.Y. Chen, M.-S. Chiu, S. Fann, C.H. Huang, T.Y. Lee, C.C. Liang, Y.-C. Liu, F.H. Tseng
NSRRC, Hsinchu, Taiwan

To acquire precise beam orbits from beam position monitors (BPMs) in storage ring is one of the most significant diagnosis to measure beam parameters. However, the precise spectrum analyses from BPM data acquisitions such as betatron tune, dynamics aperture and frequency map '..etc. that are depended on more accurate discrete Fourier transform (DFT) or the fast Fourier transform (FFT). A method of the fast Fourier transform correction (FFTc) was employed for the more accurate spectrum measurement in Taiwan Photon Source (TPS). We perform the accuracy and error analyses of this method from some spectral lines in two window functions. And the precise spectrum for betatron tune measurements and related results will be presented.

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MOPMR036

Using a Single Shot Spectrometer to Determine the Spectral Characteristics of the Beam as a Result of Micro-bunching Instabilities

detector, radiation, synchrotron, storage-ring

327

A. Finn, P. Karataev
JAI, Egham, Surrey, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
G. Rehm
DLS, Oxfordshire, United Kingdom

A single shot spectrometer has been designed and is in operation at the Diamond Light Source (DLS). It is an array of eight Schottky barrier diodes (SBDs) each with a distinct frequency band covering 33-1000 GHz. The aim of the spectrometer is to observe the bursts of coherent synchrotron radiation (CSR) as a result of micro-bunching instabilities (MBI) and stable low alpha modes, where alpha is the momentum compaction factor. In this case, the bursts of CSR occur with wavelengths in the mm regime. SBDs are often implemented as detectors in the millimetre wavelength range and benefit from low noise, excellent sensitivity and ultra-fast responses. The eight SBDs have been individually characterised thus making the results obtained comparable to simulations. Here we present, an analysis of the data obtained via the spectrometer in particular, the bursting nature and spectral characteristics of a sample of beam modes at DLS. Furthermore, the results obtained can be used to confirm simulations.

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MOPMR052

Single-shot Bunch-by-Bunch Horizontal Beam Size Measurements using a Gated Camera at CesrTA

electron, positron, ion, vacuum

364

S. Wang
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
R. Holtzapple
CalPoly, San Luis Obispo, California, USA

Funding: Work supported by NSF NSF PHY-1416318, PHYS-1068662, PHYS-1535696
A visible-light beam size monitor has been built and commissioned to measure transverse beam profiles at CESR-TA*. In order to eliminate beam jitter and to study bunch-by-bunch beam dynamics, a fast-gating camera has been utilized to measure single bunch transverse beam profiles. The minimum camera gate width is ~ 3ns which allows us to resolve single bunch beam dynamics along a CesrTA bunch train. Using single bunch interferometry at different bunch currents, we found that the horizontal beam sizes measured by gated camera are consistently less than those measured by a conventional CCD camera, demonstrating the elimination of turn-by-turn beam jitter with single shot capability. By stepping the camera trigger delay, we collected transverse beam profile images from each bunch in a 14ns-spacing 30-bunch train. The horizontal motion of each bunch as well as the horizontal beam size increases dramatically along an electron train but not along positron bunch trains under the same machine condition. The difference in single bunch horizontal dynamics may be a signature for the difference between electron cloud build-up for positron bunch trains versus ions present for electron bunch trains.
* S.T. Wang, D.L. Rubin, J. Conway, M. Palmer, D. Hartill, R. Campbell, R. Holtzapple, NIMA, 703 (2013) 80

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MOPMR054

Double-slit Interferometer Measurements at SPEAR3

electron, synchrotron, radiation, optics

368

C.L. Li, W.J. Zhang
East China University of Science and Technology, Shanghai, People's Republic of China
M.J. Boland
SLSA, Clayton, Australia
W.J. Corbett, M. Grinberg
SLAC, Menlo Park, California, USA
T.M. Mitsuhashi
KEK, Ibaraki, Japan
Y.H. Xu
DongHua University, Songjiang, People's Republic of China
W.J. Zhang
University of Saskatchewan, Saskatoon, Canada

The resolution of a conventional telescope used to image visible-light synchrotron radiation is often limited by diffraction effects. To improve resolution, the double-slit interferometer method was developed at KEK and has since become popular around the world. Based on the Van Cittert-Zernike theorem relating transverse source profile to transverse spatial coherence, the particle beam size can be inferred by recording fringe contrast as a function of interferometer slit separation. In this paper, we describe the SPEAR3 double-slit interferometer, develop a theoretical framework for the interferometer and provide experimental results. Of note the double-slit system is 'rotated' about the beam axis to map the dependence of photon beam coherence on angle.

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MOPOR046

Studies on Depolarization by Synchrotron Radiation using Elegant Particle Tracking

synchrotron, radiation, polarization, resonance

695

J.F. Schmidt, W. Hillert
ELSA, Bonn, Germany

Funding: BMBF
Spin dynamics in circular electron accelerators are significantly influenced by the emission of synchrotron light. In storage rings, Sokolov-Ternov polarization build-up and radiative depolarization have crucial impact on equilibrium polarization. On shorter timescales, as in damping rings or synchrotrons with fast energy ramp, the temporal development of polarization depends on spin decoherence caused by stochastic momentum changes. Thus, especially longitudinal beam dynamics affect depolarization. This contribution presents the implementation of particle tracking with synchrotron radiation from Elegant in an in-house developed spin tracking code. Exemplary results on depolarization including synchrotron radiation are shown.

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TUYA01

BEPCII Performance and Beam Dynamics Studies on Luminosity

luminosity, lattice, radiation, synchrotron

1014

C.H. Yu, Z. Duan, S. Gu, Y.Y. Guo, X.Y. Huang, D. Ji, H.F. Ji, Y. Jiao, Zh.C. Liu, Y.M. Peng, Q. Qin, Y.S. Sun, S.K. Tian, J.Q. Wang, N. Wang, X.H. Wang, Y. Wei, X.M. Wen, J. Wu, J. Xing, G. Xu, Y. Yue, C. Zhang, Y. Zhang
IHEP, Beijing, People's Republic of China

The upgrade of the Beijing Electron Positron Collider, BEPCII, is now in a good performance for both high energy physics and synchrotron radiation experiments. The luminosity at the design energy of 1.89 GeV reached the design value 1.0*10³³/cm²/s¹ recently. A lot of work, including accelerator physics study and technical progress, has been done for the luminosity enhancement, not only at the design energy, but all the energy region run for HEP experiments from 1.0 to 2.3 GeV. The performance of BEPCII and the process of luminosity enhancement will be described in detail.

Slides TUYA01 [5.801 MB]

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TUOAB02

Conditions for CSR Microbunching Gain Suppression

dipole, emittance, lattice, synchrotron

1057

C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
S. Di Mitri
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
D. Douglas, R. Li, C. Tennant
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The coherent synchrotron radiation (CSR) of a high brightness electron beam traversing a series of dipoles, such as transport arcs, may result in phase space degradation. On one hand, the CSR can perturb electron transverse motion in dispersive regions along the beamline, causing emittance growth. On the other hand, the CSR effect on the longitudinal beam dynamics could result in microbunching gain enhancement. For transport arcs, several schemes have been proposed* to suppress the CSR-induced emittance growth. Similarly, several scenarios have been introduced** to suppress CSR-induced microbunching gain, which however mostly aim for linac-based machines. In this paper we try to provide sufficient conditions for suppression of CSR-induced microbunching gain along a transport arc, analogous to*. Several example lattices are presented, with the relevant microbunching analyses carried out by our semi-analytical Vlasov solver***. The simulation results show that lattices satisfying the proposed conditions indeed have microbunching gain suppressed. We expect this analysis can shed light on lattice design approach that could suppress the CSR-induced microbunching gain.
*D.Douglas et al, JLAB-ACP-14-1751, S.DiMitri et al, PRL (2013), R.Hajima, NIMA (2004), Y.Jiao et al, PRSTAB (2014)
**Z.Huang et al, PRSTAB (2004), Saldin et al, NIMA (2004)
***C.Tsai et al, FEL'15

Slides TUOAB02 [6.484 MB]

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TUPMB012

Optimization of the Field Integrals of Two Small Gap IDs for CLS

multipole, wiggler, undulator, vacuum

1133

M.F. Qian, Y.Z. He, H.F. Wang, W. Zhang, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

An in-vacuum undulator and an in-vacuum wiggler have been developed for CLS at SSRF recently. The period lengths of the undulator and the wiggler are 20mm and 80mm respectively. Both IDs have the minimum gap of 5.2mm. The field integrals were measured for each magnet block with two poles and were sorted in-situ as they were installed on to the girders. Finally the field integrals of the undulator and the wiggler were shimmed by using the 'Magic Fingers' at the ends with a special algorithm. This paper reports the procedure and the results of the measurement and the optimization for the field integrals.

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TUPOR006

Systematic Studies of Short Bunch-Length Bursting at ANKA

radiation, synchrotron, shielding, electron

1662

M. Brosi, E. Blomley, E. Bründermann, N. Hiller, B. Kehrer, A.-S. Müller, M. Schedler, M. Schuh, P. Schönfeldt, J.L. Steinmann
KIT, Karlsruhe, Germany

Funding: Supported by the German Federal Ministry of Education and Research (05K13VKA), the Helmholtz Association (VH-NG-320) and by the Helmholtz International Research School for Teratronics (HIRST).
At ANKA, the Karlsruhe synchrotron radiation source, the so called short bunch-length operation mode allows the reduction of the bunch length down to a few picoseconds. The micro-bunching instability resulting from the high degree of longitudinal compression leads to fluctuations in the emitted intensity in the THz regime, referred to as bursting. For extremely compressed bunches at ANKA bursting also occurs, in a certain current range, below the main bursting threshold. This contribution shows measurements of this short bunch-length bursting and makes first comparisons with theory.

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TUPOR020

Combination of Density and Energy Modulation in Microbunching Analysis

electron, collective-effects, radiation, synchrotron

1703

C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
R. Li
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Microbunching instability (MBI) has been one of the most challenging issues in the transport of high-brightness electron beams for modern recirculating or energy recovery linac machines. Recently we have developed and implemented a Vlasov solver* to calculate microbunching gain for an arbitrary beamline lattice design, based on the extension of early theoretical formulation** for the microbunching amplification from an initial density perturbation to the final density modulation. For more thorough analyses, in addition to the case of (initial) density to (final) density amplification, we in this paper extend the previous formulation to more general cases, including energy-to-density, density-to-energy and energy-to-energy amplifications for a recirculation machine. Such semi-analytical formulae are then incorporated into our Vlasov solver, and reasonable agreement is obtained when the semi-analytical results are benchmarked with particle tracking simulation using ELEGANT***.
* C.Y. Tsai et al, FEL'15
** S. Heifets et al, PRSTAB 5, 064401 (2002), Z. Huang and K. Kim, PRSTAB 5, 074401 (2002), M. Vneturini, PRSTAB 10, 104401 (2007)
*** M. Borland, APS LS-287, 2000

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WEOAA03

Experimental Study on Optical Vortex from a Helical Undulator at UVSOR-III

undulator, radiation, experiment, synchrotron

2036

M. Hosaka
Nagoya University, Nagoya, Japan
M. Katoh, N.S. Mirian
UVSOR, Okazaki, Japan
T. Konomi, N. Yamamoto
KEK, Ibaraki, Japan
K. Kuroda
ISSP, Kashiwa-shi, Japan
K. Miyamoto, S. Sasaki
HSRC, Higashi-Hiroshima, Japan

A relativistic electron in helical undulator emits an optical vortex which carries orbital angular momentum. Sasaki and McNulty predicted theoretically that higher harmonics of helical undulator is optical vortex* and the experimental verification was made at BESSY** and UVSOR-III***. Further, we have made a systematic study to characterize the optical vortex from a helical undulator at UVSOR-III. Synchrotron radiation in UV region from an optical klystron undulator system consisting of two APPLE-II helical undulators and a buncher was used for the experiment. Patterns resulting from inferences between two undulator radiation carrying different angular momentums were clearly observed. To investigate the optical properties of the radiation, diffraction experiments were carried out. Specific diffraction patterns due to the phase singularity in the radiation center were clearly observed. The experimental results are compared with simulation.
* S. Sasaki, I. McNulty, Phys. Rev. Lett. 100, 124801 (2008)
** J. Bahrdt et al., Phys. Rev. Lett. 111, 034801 (2013)
*** e.g. S. Sasaki et al., presented in SRI2015 (2015)

Slides WEOAA03 [11.023 MB]

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WEPMW025

Optimizing the Design of Linear Non-scaling Fixed Field Alternating Gradient Arcs for the Electron Rings of eRHIC

radiation, synchrotron, lattice, electron

2475

J.S. Berg
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
I describe a process for producing optimal linear non-scaling fixed field alternating gradient (FFAG) arc designs for the electron rings of eRHIC, an electron-ion collider in the RHIC tunnel at Brookhaven National Laboratory. The electrons are accelerated in two FFAG rings (low and high energy), which in addition to the arcs optimized here, contain straight sections, splitter/combiner sections, and a linac shared between the rings. The optimization process I use has two layers, an inner one meeting constraints and an outer optimization that minimizes a target function. The target function is an approximation to the FFAG arc cost, for which I give the function used and the basis for that choice. While reducing synchrotron radiation is important, I show that optimizing for synchrotron radiation alone leads to significant cost an performance penalties for the rest of the machine design for very little reduction in synchrotron radiation. I describe important constraints on the design, in particular minimum drift lengths, maximum and minimum tunes, and clearance from the beam to the beam pipe. Finally, I present possible eRHIC FFAG parameters resulting from this optimization.

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WEPMW044

Start-to-End Simulation of eRHIC ERL

linac, electron, simulation, emittance

2535

Y. Hao, S.J. Brooks, Y.C. Jing, F. Méot, V. Ptitsyn, D. Trbojevic, N. Tsoupas
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The ERL-ring eRHIC adopts the electron accelerator design of a multi-pass energy recovery linac (ERL), with fixed field alternating gradient (FFAG) recirculating passes. To ensure the beam quality in the accelerating and decelerating stage and the energy recovery efficiency, detailed start-to-end simulation is required to evaluate the various beam dynamics effects, such as synchrotron radiation, wake fields, coherent synchrotron radiation. In this paper, we present the eRHIC ERL start-to-end simulation strategy with various simulation codes and the current status.

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WEPMY042

Effective Cycling and Ramping

power-supply, TANGO, synchrotron, device-server

2651

Ł. Żytniak, L.J. Dudek, P.P. Goryl, A. Kisiel, W.T. Kitka, A.I. Wawrzyniak
Solaris, Kraków, Poland
P.J. Bell, V.H. Hardion, D.P. Spruce
MAX IV Laboratory, Lund University, Lund, Sweden
G. Gaio
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The National Synchrotron Radiation Centre Solaris, Kraków, Poland has been successfully built in collaboration with several institutes and organizations. The MAX IV Laboratory, Lund, Sweden and Elettra, Trieste, Italy, are the most important synchrotron partners. Solaris has built as an adaptation of MAX-IV 1.5 GeV ring and linear accelerator based on the same components as the ones of MAX-IV, therefore the device server for the magnet circuit has been developed by MAX-IV. Ramping was included in expert consultancy services contract won by Elettra. Solving problem with the power supplies stability and thanks to usage snapshots as steps for ramping it was possible to ramp the beam without losing current linearly.

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WEPOR023

Radiation Shielding Considerations for CEPC-SPPC

radiation, shielding, synchrotron, monitoring

2722

Z.J. Ma, Y.D. Ding, N. Li, Q.B. Wang, M.Y. Yan, Q.J. Zhang
IHEP, Beijing, People's Republic of China

A planned project CEPC-SPPC is under-researched by IHEP, CAS, China. Due to its big circumference and high energy, the radiation shielding issues should be treated more serious than ever whether for the machine itself or the worker and the public. In this paper, we briefly introduce the configurations and parameters of the machine, the tools and principle used in the radiation shielding design, and discuss the preliminary result for the shielding of main tunnel and the synchrotron radia-tion. Some radiation protection issues are listed to be resolved next. All the aspects presented should be dis-cussed and verified, any other unmentioned radiation protection problems will be excavated in the future.
CEPC: Circular Electron-Positron Collider
SPPC: Super Proton-Proton Collider
IHEP: Institute of High Energy Physics
CAS: Chinese Academy of Sciences

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WEPOW015

Influence of Filling Pattern Structure on Synchrotron Radiation Spectrum at ANKA

synchrotron, radiation, storage-ring, detector

2855

J.L. Steinmann, E. Blomley, M. Brosi, E. Bründermann, C.M. Caselle, N. Hiller, B. Kehrer, A.-S. Müller, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, M. Siegel
KIT, Karlsruhe, Germany

Funding: This work is supported by the Helmholtz International School for Teratronics (HIRST)
We present the effects of the filling pattern structure in multi-bunch mode on the beam spectrum. This effects can be seen by all detectors whose resolution is better than the RF frequency, ranging from stripline and Schottky measurements to high resolution synchrotron radiation measurements. Our heterodyne measurements of the emitted coherent synchrotron radiation at 270 GHz reveal discrete frequency harmonics around the 100 000th revolution harmonic of ANKA, the synchrotron radiation facility in Karlsruhe, Germany. Significant effects of bunch spacing, gaps between bunch trains and variations in individual bunch currents on the emitted CSR spectrum are described by theory and supported by observations.

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WEPOW023

Present Status of Accelerators in Aichi Synchrotron Radiation Center

synchrotron, radiation, storage-ring, injection

2877

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

Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.

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WEPOY004

Integrated Green Function for Charged Particle moving along Bending Orbit

radiation, synchrotron, simulation, collider

2997

K. Ohmi, S. Chen
KEK, Ibaraki, Japan
H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

Electro-magnetic field for moving charged particle is given by Liennard-Wiechert potential. The field contains high frequency component corresponding to synchrotron light, ω=3cγ³/(2ρ). The frequency is too high to study beam behavior generally. Green function integrated over beam distribution and/or over in a region σ_x/n_x× σ_y/n_y× σ_z/n_z (n_xyz ∼ 10) is useful to study instability and emittance growth of the beam. The green function is regarded as the wake field for coherent synchrotron radiation in three dimension space.

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WEPOY060

YACS - Progression Towards Isoparametric 2.5D Finite Elements

cavity, software, radiation, experiment

3135

B.D. Isbarn, B. Riemann, M. Sommer, T. Weis
DELTA, Dortmund, Germany

Funding: Work supported by the BMBF under contract no. 05K13PEB.
YACS is a 2.5D finite element method solver capable of solving for the full 3D eigenfrequency spectra of resonant axisymmetric structures while reducing the computational problem to a 2D rotation plane. Prior studies and benchmarks, comparing YACS to well known commercial 3D and 2D applications, already demonstrated its capabilities of performing fast optimizations of geometries, due to its minimal computational overhead. However, because of the first order elements and basis functions used for approximation of the domain and field, this solving speed advantage vastly diminishes when targeting higher accuracies. In order to circumvent these issues, YACS was upgraded to support arbitrary order basis functions and curved meshes, leading to, but not limited to, isoparametric finite elements. This led to distinct performance and convergence improvements, especially when considering curved geometries, ideally representable by a polynomial mapping, e.g. when choosing a cavity geometry parametrization based on splines.

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THPMB025

The Effect of Magnetic Field on the Secondary Electron Yield in the Ultra-High Vacuum Environment

electron, gun, permanent-magnet, vacuum

3281

J. Wang, Y. Wang, W. Wei, Y.H. Xu, B. Zhang, T. Zhang, Y.X. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

A secondary electron emission measurement system has been designed and used to study the secondary electron emission (SEE) of different materials with an independently adjustable energy of 50 eV to 5 keV at National Synchrotron Radiation Laboratory. Here, we obtained the characteristics of the SEE yield from Pd film coatings, under the condition of magnetic field and without magnetic field. Then it was analysed that the effect of magnetic field on the secondary electron yield in the ultra-high vacuum environment. The results show that magnetic field shielding is critical to avoid the influence of magnetic field during secondary electron yield (SEY) measurements.

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THPMB026

Research on Low Secondary Electron Yield Materials for Future Accelerators

electron, vacuum, laser, proton

3284

J. Wang, Y. Wang, W. Wei, Y.H. Xu, B. Zhang, T. Zhang, Y.X. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

For future accelerators, such as SPPC (SEYmax <1.2), the build-up of electron cloud generated in the beam pipes considerably affect the stability of particle beams. Therefore, it is critical to look for steady and low secondary electron yield (SEY) material for future high intensity accelerators.

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THPMB034

Short Bunch Operation Mode Development at the Synchrotron Radiation Source Siberia-2

operation, optics, emittance, synchrotron

3305

Y.A. Fomin, V. Korchuganov, S.I. Tomin, A.G. Valentinov
NRC, Moscow, Russia

Decrease of the electron bunch length gives rise to coherent synchrotron radiation in the THz spectral region. Also, the short photons pulse could provide an option for time-resolved processes studies. Currently the possibility to operate with short electron bunch of the synchrotron radiation source Siberia-2 is under consideration for this purpose. In the report the techniques of electron bunch shortening are described as well as the requirements are given for the parameters of the electron bunch and lattice. The authors present a modified lattice for the synchrotron radiation source Siberia-2 with low momentum compaction factor and the results of the beam dynamics studies.

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THPMR045

CLIC Beam Delivery System Rebaselining and Long L* Lattice Optimization

luminosity, lattice, sextupole, radiation

3500

F. Plassard, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
P. Bambade
LAL, Orsay, France

This paper summarizes the re-optimization study made on the CLIC Beam Delivery System (BDS) in the framework of the rebaselining for beam collisions at 380 GeV for the initial energy stage. It describes the optimization process applied for the beam parameters as well as for the Final Focus system (FFS) lattice design with respect to the energy upgrade transition to 3 TeV. Both initial and final energy stages were optimized for a short (nominal) and a long L* (6 meters). The long L* option allows the last quadrupole (QD0) to be be located outward of the detector solenoid field influence. FFS optics designs based on the Local chromaticity correction and performance comparisons for both L* options are shown.

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THPMY011

Chamber Upgrade for EPU48 in TPS

vacuum, storage-ring, synchrotron, radiation

3676

I.C. Sheng, C.K. Chan, C.-C. Chang, C.M. Cheng, Y.T. Cheng, J. -Y. Chuang, Y.M. Hsiao, Y.T. Huang, C. Shueh, L.H. Wu, I.C. Yang
NSRRC, Hsinchu, Taiwan

Due to high total power and power density in Taiwan Photon Source (TPS) of EPU48 (Elliptical Polarized Undulator) in double minimum sector, we fabricate a new Aluminum vacuum chamber to increase sufficient room for synchrotron radiation to pass through without damage the storage ring chamber. A new method of in-site replacement of bending chamber is also presented, the result of this replacement procedure shows that it is very cost-effective as well as good UHV vacuum quality.

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THPMY014

Study of the Non-evaporable Ti-Zr-V Films Grown on Different Materials

vacuum, electron, experiment, booster

3682

L.H. Wu, C.M. Cheng, Y.T. Huang, S.Y. Perng, I.C. Sheng, C. Shueh
NSRRC, Hsinchu, Taiwan

The non-evaporable (NEG) Ti-Zr-V films were coated on the different vacuum-chamber materials, including the extruded aluminum samples (Al), the extruded seamless stainless steel samples (S.S.), CuCrZr alloys, and oxygen-free copper (OFC) plates. The NEG films were fabricated by using the direct current (DC) sputtering method. The secondary electron microscopy images showed that the morphology of NEG films was different on these various substrates. The thermal analysis (TA) presented that exothermic reaction happened by heating the samples.

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THPMY034

Power Saving Status at NSRRC

controls, radiation, synchrotron, operation

3734

J.-C. Chang, W.S. Chan, Y.C. Chang, C.S. Chen, Y.F. Chiu, Y.-C. Chung, K.C. Kuo, M.T. Lee, Y.-C. Lin, C.Y. Liu, Y.-H. Liu, Z.-D. Tsai, T.-S. Ueng, J.P. Wang
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan currently operates two synchrotrons, the Taiwan Light Source (TLS) and Taiwan Photon Source (TPS). The former one has been operated for more than 22 years, while the latter is in commissioning phase. We target of the beam current on 500 mA. Thus, the power consumption increases higher than ever. Currently, the contract power capacities of the TLS and TPS with the Taiwan Power Company (TPC) are 5.5MW and 7.5MW, respectively. The ultimate power consumption of the TPS is estimated about 12.5MW. To cope with increasing power requirement, we have conducting several power saving schemes for years. This paper presents our latest power schemes, which include installation of power saving fan for the cooling tower, adjustment of supply air temperature according to the atmosphere enthalpy, replacement of old air conditioning unit (AHU), power consumption control by the operation of chillers, and power factor improvement.

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THPOY023

Upgrade of NSLS-II Active Interlock System

storage-ring, operation, synchrotron, radiation

4140

S. Seletskiy, J. Choi, K. Ha, R.M. Smith
BNL, Upton, Long Island, New York, USA

The NSLS-II Storage Ring is protected from possible damage from synchrotron radiation by a dedicated active interlock system (AIS). The AIS monitors electron beam position and angle and triggers beam drop if beam orbit exceeds the boundaries of pre-calculated active interlock envelope. The one year worth of the AIS operation showed that there is a number of erroneous machine trips associated with the AIS. In this paper we describe an upgrade of the AIS that allowed us to get rid of the Storage Ring faults and improved the overall NSLS-II reliability.

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THPOY047

Comprehensive Approach to Synchrotron Radiation Protection of NSLS-II

radiation, synchrotron, electron, undulator

4211

S. Seletskiy, T.V. Shaftan
BNL, Upton, Long Island, New York, USA

To protect the NSLS-II Storage Ring components from possible damage from synchrotron radiation produced by insertion devices (IDs) and bending magnets (BMs) the Active Interlock System (AIS) keeps electron beam within the AI safe envelope (AIE) in the transverse phase space. The NSLS-II beamlines (BLs) and frontends (FEs) are designed under assumption that above certain safe beam current the ID synchrotron radiation (IDSR) fan is produced by the interlocked e-beam. In this paper we describe a new approach to defining the AIS parameters and settings, which significantly simplifies the process of the FE and BL design.

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