IPAC2011 - List of Keywords (photon)

Paper	Title	Other Keywords	Page
MOPO032	The Survey Status at NSRRC during the TPS Civil Construction	survey, alignment, controls, site	553
	H.M. Luo, J.-R. Chen, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang NSRRC, Hsinchu, Taiwan
	In this paper, the survey status at NSRRC site duirng the TPS (Taiwan Photon Source) civil construction is described. The TLS (Taiwan Light Source) ring is still under operation in the meantime. In order to maintain the TLS for normal operation and also monitoring the building construction, an expanded survey setups including permanent leveling and GPS monuments were installed both on the site and TPS building. Combined with the orignal TLS survey sockets and sensor monitoring system (hydrostatic leveling system and precision inclination sensors) installed both in the TLS storage ring and beamlines, an extensive survey tasks were performed. The ground deformation situation of the TLS and deviation of the TPS building construction are presented.

MOPO034	From Survey Alignment toward Auto-alignment for the Installation of the TPS Storage Ring Girder System	laser, survey, alignment, controls	559
	T.C. Tseng, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, H.S. Wang NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	The TPS (Taiwan Photon Source) project is now under civil construction. The whole building is constructed half underground and 12m deep compared to the TLS due to the stability consideration, so the survey and alignment works are quite confined and difficult. For positioning the magnets precisely and quickly, a high accuracy auto-tuning girders system combined with survey network procedures were established to accomplish the installation tasks. The position data from the survey network will define a basis for the motorized girder system to auto-tune and improve the accuracy. A mockup of one twenty-fourth section (one cell) had been installed at NSRRC for interface examination and further testing. In this paper, the procedures from the traditional survey network to auto-aliment system design and algorithm are described. Meanwhile, a preliminary testing result is also included.

MOPO043	Applications of Lasers to Accelerator Physics at SSRL	laser, gun, cathode, electron	580
	D.L. Robinson Cal Poly, San Luis Obispo, California, USA W.J. Corbett SLAC, Menlo Park, California, USA
	Recent advances in accelerator physics and SR research have generated the need for high-power lasers in the SPEAR3 accelerator complex. On the injector side, two lasers are being used to test different photocathode materials and to provide photo-assisted emission from the standard dispenser cathode RF gun. For the storage ring, both a TiSa oscillator and a fiber laser locked to the RF master oscillator have been used to characterize short-pulse electron bunches in cross-correlation experiments. These lasers are also used in SR experiments for pump-probe characterization of materials. In this paper we review the laser-based systems, preliminary results and outlook for the future.

MOPO044	Bunch Length Measurements in Low-Alpha Mode at SPEAR3 with First Time-Resolved Pump/Probe Experiments*	laser, synchrotron, single-bunch, radiation	583
	J.S. Wittenberg, A. Lindenberg, A. Miller Stanford University, Stanford, California, USA W.J. Corbett, L. Wang SLAC, Menlo Park, California, USA
	Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515, Office of Basic Energy Sciences and SLAC Laboratory Directed Research Development funds (LDRD) The SPEAR3 synchrotron light source can be operated in low-alpha mode to generate x-ray pulse durations of order 1ps, well below streak camera resolution limits yet accessible by laser/sr cross-correlation measurements. Initial CC tests performed with a 50fs TiSa laser, frequency doubling BBO, photodiode and lock-in amplifier resolved bunch lengths down to about 6ps rms with 85uA single-bunch current. By reconfiguring the experimental setup to utilize a fiber laser, sum frequency generation and single photon counter it is now possible to measure profiles in the 1ps rms range with only 5uA single-bunch current. In this paper we report on the most recent measurements, simulations, modeling efforts and prospects for further improvement.

MOPS050	Electron Beam Dynamics in the 50 MeV ThomX Compact Storage Ring	electron, emittance, scattering, collective-effects	715
	C. Bruni, J. Haissinski LAL, Orsay, France A. Loulergue, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	ThomX is a high flux compact X-ray source based on Compton back scattering between a relativistic electron beam and an intense laser pulse. To increase the repetition rate, the electron beam is stored in a ring. The main drawback of such a scheme is the low energy of the electrons regarding collective effects and intrabeam scattering. These effects tend to enlarge or even disrupt the stored bunch and they limit its charge, especially in a system where damping plays a negligible role. Thus such collective effects reduce the maximum X-ray flux and it is important to investigate them to predict the performance of this type of X-ray source. In addition, the Compton back scattering acts on the electron beam by increasing its energy spread. This presentation will show firstly the impact of collective effects on the electron beam, essentially during the first turns when they are the most harmful. Then, the reduction of the X-ray flux due to Compton back scattering and intrabeam scattering will be investigated on a longer time scale.

MOPS083	Update on Electron Cloud Mitigation Studies at Cesr-TA*	electron, wiggler, positron, resonance	796
	J.R. Calvey, M.G. Billing, J.V. Conway, G. Dugan, S. Greenwald, Y. Li, X. Liu, J.A. Livezey, J. Makita, R.E. Meller, M.A. Palmer, S. Santos, R.M. Schwartz, J.P. Sikora, C.R. Strohman CLASSE, Ithaca, New York, USA S. Calatroni, G. Rumolo CERN, Geneva, Switzerland K. Kanazawa, Y. Suetsugu KEK, Ibaraki, Japan M.T.F. Pivi, L. Wang SLAC, Menlo Park, California, USA
	Funding: Work supported by the US National Science Foundation (PHY-0734867) and Department of Energy (DE-FC02-08ER41538) Over the course of the past three years, the Cornell Electron Storage Ring (CESR) has been reconfigured to serve as a test facility for next generation particle accelerators. A significant part of this program has been the installation of several diagnostic devices to measure and quantify the electron cloud effect, a potential limiting factor in these machines. In particular, more than 30 Retarding Field Analyzers (RFAs) have been installed in CESR. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. This paper will provide an overview of RFA results obtained at CesrTA over the past year, including measurements taken as function of bunch spacing and wiggler magnetic field. Understanding these results provides a great deal of insight into the behavior of the electron cloud.

TUZA01	Commissioning and Initial Operation of FERMI@Elettra	FEL, electron, laser, undulator	918
	S. Di Mitri, E. Allaria, R. Appio, L. Badano, S. Bassanese, F. Bencivenga, A.O. Borga, M. Bossi, E. Busetto, C. Callegari, F. Capotondi, K. Casarin, D. Castronovo, P. Cinquegrana, D. Cocco, M. Cornacchia, P. Craievich, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, P. Delgiusto, A.A. Demidovich, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, S. Ferry, V. Feyer, L. Fröhlich, P. Furlan Radivo, G. Gaio, F. Gelmetti, L. Giannessi, R. Gobessi, R. Ivanov, E. Karantzoulis, M. Kiskinova, M. Lonza, A.A. Lutman, C. Masciovecchio, R.H. Menk, M.M. Milloch, M.M. Musardo, I. Nikolov, S. Noe, F. Parmigiani, L. Pavlovič, E. Pedersoli, G. Penco, M. Petronio, M. Predonzani, E. Principi, E. Quai, G. Quondam, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Wang, M. Zaccaria, D. Zangrando ELETTRA, Basovizza, Italy M. Alagia, A. Kivimaki, M. Zangrando, M. de Simone IOM-CNR, Trieste, Italy L. Avaldi, P. Bolognesi, M. Coreno, P. O’Keeffe CNR - IMIP, Trieste, Italy M. Dal Forno DIEIT, Trieste, Italy G. De Ninno, S. Spampinati University of Nova Gorica, Nova Gorica, Slovenia M. Devetta, T. Mazza, P. Piseri Università degli Studi di Milano, Milano, Italy E. Ferrari Università degli Studi di Trieste, Trieste, Italy S. Stranges Università di Roma "La Sapienza", Roma, Italy
	Funding: Work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3. This article describes the design goals of FERMI@Elettra, reports on the goals achieved so far and shows how the facility development has been driven by the new research frontier of ultra-fast, extreme ultra-violet and soft X-ray science. The commissioning phases and first experience with user pilot experiments are presented and discussed.
	Slides TUZA01 [13.401 MB]

TUOAB02	Simultaneous Long and Short Bunch Operation in an Electron Storage Ring - a Hybrid Mode based on Nonlinear Momentum Compaction	electron, storage-ring, synchrotron, octupole	945
	M. Ries, J. Feikes, A. Jankowiak, P.O. Schmid, G. Wüstefeld HZB, Berlin, Germany
	The generation of short pulses in electron storage rings is driven by different user groups like time resolved x-ray spectroscopy users or users of coherent synchrotron radiation. The required optics and operation conditions to generate this short bunches are worsening the experimental conditions, e.g. strongly reducing the average photon flux, for the regular user. Therefore short bunch operation is usually limited to dedicated user shifts. By controlling higher orders of the momentum compaction factor by higher multipoles it is possible to introduce a hybrid mode and simultaneously supplying long and short bunches. The Metrology Light Source (MLS) has the means to control these higher orders, therefore it is an ideal machine to investiate the feasibility of such a hybrid mode. Tracking results and first measurements will be shown. D. Robin et al., Proc. of EPAC08, p. 2100-2102, Genoa, Italy (2008). ** J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
	Slides TUOAB02 [7.817 MB]

TUODB01	Progress of the Construction for the TPS Vacuum System	vacuum, impedance, ion, storage-ring	976
	G.-Y. Hsiung, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, S-N. Hsu, H.P. Hsueh, I.T. Huang, T.Y. Lee, I.C. Sheng, L.H. Wu, H.Y. Yan, Y.C. Yang, C.S. huang NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	Vacuum system for the 3 GeV Taiwan Photon Source (TPS) has been started the construction since 2010. The critical components such as the bellows and gate valves with rf-contact shielding, pulsed magnet kicker ceramic chambers, BPM, crotch absorbers, etc. have been manufactured and tested. Aluminum alloy (Al-) vacuum chambers for the arc-cells have been machined and undergoing the in-house welding. Mass production of the vacuum equipments including the ion gauges, ion pumps, NEG pumps, and gate valves, has been contracted out and partially delivering following the schedule of the cell assembling. Each cell, contains two short Al-straight chambers and two Al-bending chambers, has been started the assembling and on-site welding on the pre-aligned girders in clean room forming an one-piece vacuum vessel about 14 m in length following by the vacuum baking to the ultra-high vacuum. The conceptual design of the vacuum systems for the long straight sections, the concentric booster, and the transport lines, will be addressed. The progress of prototyping development and the status of construction for the TPS vacuum system will be described in this paper.
	Slides TUODB01 [35.595 MB]

TUPC001	Simulations of the Interaction Point for TeV-scale e⁺ e− Colliders	electron, simulation, collider, radiation	985
	J. Esberg Aarhus University, Aarhus, Denmark
	The design of a detector and post collisional line of a future linear collider calls for detailed knowledge of the beam-beam dynamics at the interaction point. We here describe the implementation and results of new simulation tools in the program GUINEA-PIG. The subjects are direct trident production relevant in the deep quantum-regime, incoherent muon generation, synchrotron radiation from secondary particles and depolarization effects. We choose beam parameters in the range relevant for CLIC and comment on the implications for the design of such a machine.

TUPC005	Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider	target, positron, collider, linear-collider	994
	O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva University of Hamburg, Hamburg, Germany A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov DESY, Hamburg, Germany A. Schälicke, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC006	Production of Highly Polarized Positron Beams*	polarization, undulator, positron, target	997
	A. Ushakov, O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva, G.A. Moortgat-Pick University of Hamburg, Hamburg, Germany A.F. Hartin DESY, Hamburg, Germany S. Riemann, A. Schälicke, F. Staufenbiel DESY Zeuthen, Zeuthen, Germany
	Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE Using of polarized electron and positron beams significantly increases the physics potential of future linear colliders. The generation of an intense and highly polarized positron beam is a challenge. The undulator-based positron source located at the end of electron linac is the baseline source for the International Linear Collider. In case of a 250 GeV drive beam energy, an helical undulator with K = 0.92, an undulator period of 11.5 mm and a titanium alloy target of 0.4 radiation length thickness, the average polarization of the generated positrons is relatively low (about 22 percent). In this contribution, the possibilities of increasing the positron polarization have been considered by adjusting the undulator field and selecting those photons and positrons that yield a highly polarized beam. The detailed simulations have been performed with our developed Geant4-based application PPS-Sim. http://pps-sim.desy.de

TUPC027	CLIC Post-Collision Line Luminosity Monitoring	luminosity, simulation, monitoring, feedback	1057
	R. Appleby UMAN, Manchester, United Kingdom A. Apyan, L.C. Deacon, E. Gschwendtner CERN, Geneva, Switzerland
	The CLIC post collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14 MW to the main beam dump. Full Monte Carlo simulation has been done for the description of the Compact Linear Collider (CLIC) luminosity monitoring at the post collision line. One method of the luminosity diagnostic is based on the detection of high energy muons produced by the beamsstrahlung photons in the main beam dump. The disrupted beam and the beamsstrahlung photons produce at the order of 10⁶ muons per bunch crossing, with energies greater than 10 GeV. Currently threshold Cherenkov counters are considered after the beam dump for the detection of these high energy muons. A second method using the direct detection of the beamsstrahlung photons is also considered.

TUPC028	Background and Energy Deposition Studies for the CLIC Post-Collision Line*	simulation, radiation, positron, electron	1060
	R. Appleby, M.D. Salt UMAN, Manchester, United Kingdom L.C. Deacon, E. Gschwendtner CERN, Geneva, Switzerland
	The CLIC post-collision line is designed to transport the spent-beam products of collision to their respective dumps, with minimal losses and thus minimal background contributions. With nanometre spot-sizes at TeV energies, large beam-beam effects induce divergence and dispersion of the outgoing beams, with a large production cross-section of Beamstrahlung photons and subsequently coherent pairs. The post-collision line should provide sufficient divergence of the beam to avoid damage to the vacuum exit and dump entrance windows. In this study, the beam losses are investigated, with the production of secondary particles from the interaction with matter simulated. The particle flux leakage from absorbers and dumps is modelled to determine the total energy deposited on magnets of the post-collision line. Finally, both electromagnetic and hadronic backgrounds at the CLIC experiment are considered.

TUPC048	First Measurement Results of the LHC Longitudinal Density Monitor	proton, ion, synchrotron, diagnostics	1105
	A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo CERN, Geneva, Switzerland A.S. Fisher SLAC, Menlo Park, California, USA C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The primary author is funded by the E.U. under the DITANET Marie Curie network. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, for example to check the injection quality and to characterize the development of ghost bunches before and during the physics periods. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. The LDM is able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10⁵ to be achieved. The LDM operated during the 2010 lead ion run and during 2011 with protons. Measurements from both runs are presented in this contribution along with an analysis of the LDM performance and an outlook for future upgrades.

TUPC068	SOLEIL Beam Orbit Stability Improvements	feedback, booster, synchrotron, power-supply	1156
	N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

TUPC069	Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL	radiation, undulator, optics, electron	1159
	M.-A. Tordeux, F. Dohou, M. Labat, O. Marcouillé SOLEIL, Gif-sur-Yvette, France
	Bunch length measurements can be made by analysing the pulse to pulse intensity fluctuation of the incoherent synchrotron radiation as it has been reported elsewhere. Such a method has been tested at SOLEIL for picosecond bunch durations, at several wavelengths and bandwidths in the visible range, using an avalanche photodiode. Thanks to the low-alpha optics the lengths of 10 μA bunches as short as 3 ps have been measured in good agreement with the streak camera results. We first used the radiation from a bending magnet, and then from a HU640 undulator that enhances the photon flux. Moreover, taking advantage of using the radiation from an undulator, we show that the method can still be used when the number of spikes emitted by the electron bunch is reduced to a few hundreds. This could be of interest for bunch length measurements of X-ray SASE FELs. Furthermore, we intend to use a single crystal diamond detector in order to perform these measurements in the X-ray range. F. Sannibale et al., "Absolute bunch length measurements by incoherent radiation fluctuation analysis", PRST AB 12, 032801 (2009).

TUPC072	Accurate Electron Beam Size Measurement at the Metrology Light Source	electron, radiation, polarization, storage-ring	1165
	R. Klein, G. Brandt, R. Thornagel PTB, Berlin, Germany J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	For the operation of the Metrology Light Source (MLS), the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB), as the national primary radiation source standard from the near infrared to the vacuum ultraviolet spectral region, all storage ring parameters which are relevant for the calculation of the radiant intensity by the Schwinger equation have to be known absolutely with small uncertainties. For the measurement of the effective vertical electron beam size a Bragg polarimeter, operating at a photon energy of 1103 eV, has been designed and put into operation. This system also serves as a detection system for the image of the electron beam through a set of narrow slits. The results obtained with the new device are compared to those measured by an optical beam imaging system. R. Klein et al., Phys. Rev. ST-AB 11, 110701 (2008). ** C. Koschitzki et al., Proc. IPAC10, 894-896 (2010).

TUPC074	A New Counting Silicon Strip Detector System for Precise Compton Polarimetry	electron, polarization, laser, scattering	1171
	R. Zimmermann, W. Hillert, J.C. Wittschen ELSA, Bonn, Germany
	Funding: Supported by the German Research Foundation within the SFB/TR16 A Compton polarimeter is currently being installed at the Electron Stretcher Facility ELSA to monitor the degree of polarization of the stored electron beam. For this purpose, circularly polarized light that is emitted by a laser and backscattered off the beam has to be detected. Above all, as a result of ELSA's beam energies, it is necessary to measure the shift of the center of the photon spatial distribution which is obtained when the polarization of the laser is switched from left-hand to right-hand circular polarization with an accuracy of a few microns. In order to meet the required specifications, a new counting silicon strip detector system has been developed in cooperation with the SiLab/ATLAS group of the Physics Institute of the University of Bonn. In this contribution, the design of the system will be presented and first results will be shown.

TUPC081	Diagnostics of Femtosecond Low-charge Electron Bunches at REGAE	electron, diagnostics, laser, simulation	1192
	S. Bayesteh Uni HH, Hamburg, Germany H. Delsim-Hashemi DESY, Hamburg, Germany
	A new linac is constructed at DESY as the electron source fo "Relativistic Electron Gun for Atomic Exploration (REGAE)". REGAE is mainly established for a Femtosecond electron diffraction experiment presenting structural information on atomic transition states occurring in the sub-hundred femtosecond time-scale. REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell RF cavity to provide sub pico-Coulomb charge of 2 to 5 MeV energy with a coherent length in the range of 30nm. In order to produce and maintain such high quality electron bunches, sophisticated single-shot diagnostics is mandatory to monitor the properties. Diagnostics include emittance, energy, energy spread and bunch length measurement. In this paper the conceptual ideas and steps toward realization of these diagnostics are presented with a detailed focus on transverse diagnostics. As for photon source of transversal diagnostics, scintillators are studied. Simulation results show which material suits the best for REGAE parameters. Layout of a home-made intensified camera is presented. The method discussed in this paper would also be advantageous for low-charge Free Electron Lasers.

TUPC083	Comparative Studies into 3D Beam Loss Simulations	simulation, beam-losses, electron, positron	1198
	M. Panniello MPI-K, Heidelberg, Germany C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328. A detailed understanding and monitoring of potential beam loss mechanisms is crucial for every particle accelerator. The main motivation in low energy facilities, such as the Ultra-low energy Storage Ring (USR) at the future Facility of Low energy Antiproton and Ion Research (FLAIR), comes from the very low number of particles available which in such machine ought to be conserved. In High Energy accelerators it is the concern about activation or even physical damage of machine parts which has to be taken into serious account. The CLIC Test Facility (CTF3) at CERN provides an ideal testing ground for studies into novel BLM systems and is well suited for benchmarking the results from numerical simulations in experiments. This contribution summarizes the three-dimensional beam loss pattern as found with the commonly used codes FLUKA and Géant4. The results from these codes are compared and analyzed in detail and used for the identification of optimum beam loss monitor locations.

TUPC087	Filling Pattern Measurements at the ANKA Storage Ring	electron, storage-ring, single-bunch, synchrotron	1209
	B. Kehrer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale KIT, Karlsruhe, Germany
	For many accelerator physics studies, e.g. the investigation of coherent synchrotron radiation (CSR), a precise knowledge of the quantitative filling pattern (i.e. the number of electrons per bunch) is essential. This can be achieved by either using a linear detector (analog recording) or by employing the method of time-correlated single photon counting (TCSPC). At the ANKA storage ring both methods are in use. The analogue detection is based on the signal from a stripline or annular electrode, the TCSPC uses a Single Photon Avalanche Diode (SPAD). In this paper, we describe the experimental set-ups and present results of a comparison of the two techniques for single as well as for multi bunch filling patterns.

TUPC088	An Ionization Profile Monitor for the Determination of the FLASH and PITZ Beam Parameters	electron, vacuum, diagnostics, ion	1212
	J. Mießner, H.-J. Grabosch, M. Markert, R. Sternberger DESY Zeuthen, Zeuthen, Germany A. Hofmann KIT, Karlsruhe, Germany K.I. Tiedtke DESY, Hamburg, Germany
	To operate FLASH (Free-electron LASer at Hamburg) successfully, accurate measurements of the photon beam parameters, like position and profile, are essential. The development of a specific Ionization Profile Monitor (IPM) is one contribution to the photon beam diagnostics, and currently one horizontal and one vertical oriented IPM are installed at FLASH. The working principle of the IPM is based on the detection of ions generated by interactions of the photon beam with the residual gas, which is always present in the beam line. An essential advantage of this method is that the beam is not influenced by the IPM, so it is possible to analyze the beam parameters without beam destruction. Moreover, the monitor is able to determine the relative position and the spatial profile of the beam with the precision of a few um. In this poster, the design and first measurements with the IPM taken at FLASH are presented. A good measuring accuracy of the IPM is obtained. Moreover, first results of measurements at PITZ (PhotoInjector Testfacility at Zeuthen) are given for one vertical oriented IPM with a up to 25 MeV electron beam.

TUPC112	Photon Beam Position Monitor based on Position-sensitive Detector for HLS*	synchrotron, injection, diagnostics, feedback	1281
	Y.Y. Xiao, L.M. Gu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In order to overcome the limitation that the existing photon beam position monitors (PBPM) cannot measure the beam position in vertical and horizontal at the same time, a new photon beam position monitor based on position-sensitive detector (PSD) has developed at HLS (Hefei Light Source). The new PBPM based on the PSD has very fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. Some results are given.

TUPC121	Development of MCP Based Photon Detectors for the European XFEL	radiation, FEL, background, vacuum	1299
	E. Syresin, M.N. Kapishin JINR, Dubna, Moscow Region, Russia O.I. Brovko, A.V. Shabunov JINR/VBLHEP, Moscow, Russia W. Freund, J. Grünert, H. Sinn European XFEL GmbH, Hamburg, Germany M.V. Yurkov DESY, Hamburg, Germany
	To provide successful operation of SASE XFEL the radiation detectors should operate in wide dynamic range from the level of spontaneous emission to the saturation level, in wide wavelength range from 0.05 nm to 0.16 nm for SASE1 and SASE2 and from 0.4 nm to 4.4 nm for SASE3. High relative accuracy of measurements is crucial for detection of a signature of lasing, tuning of amplification process, and characterization of statistical properties of the radiation. The XFEL radiation detector based on micro-channel plates (MCP) meets these requirements. Two types of the photon detector are used for measurements of the pulse radiation energy and the image of the photon beam. The dynamic range of photon pulse energies is between 1 nJ and 10 mJ. This applies to spontaneous and FEL radiation. The relative accuracy of pulse energy measurements is better than 1%. The visualization of a single bunch in a train, or average image over the full train will perform by the MCP imager at a spatial resolution of 30 μm.

TUPC124	Laser Wire Emittance Measurement Line at CLIC*	laser, emittance, collider, electron	1308
	H. Garcia, Yu.A. Kubyshin UPC, Barcelona, Spain T. Aumeyr, G.A. Blair JAI, Egham, Surrey, United Kingdom D. Schulte, F. Stulle CERN, Geneva, Switzerland
	A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical and machine-related errors and of their impact on the accuracy of the emittance reconstruction are given. Modes of operation of the laser wire system and its main characteristics are discussed.

TUPC129	A Beam Position System for Hadrontherapy Facilities	electron, controls, vacuum, proton	1323
	A. Faus-Golfe, C. Belver-Aguilar, C. Blanch Gutierrez, J.J. García-Garrigós IFIC, Valencia, Spain E. Benveniste, M. Haguenauer, P. Poilleux LLR, Palaiseau, France
	Funding: MICINN-FPA:AIC10-D-000518 Essential parts of the needed instrumentation for the beam control in the Hadrontherapy accelerators are the Beam Position Monitors (BPM). The measurement of the beam position in Hadronterapy accelerators become more important at the secondary transport lines towards the patient room where this parameter must be completely determined. The BPM described in this paper is a new type of BPM based on four scintillating fibers coupled to four photodiodes to detect the light produced by the fibers when intercepting the beam. We present here the study of the different photodiodes able to read the light emitted by the scintillating fiber, the tests performed in order to find the most suitable photodiode to measure the beam position from the variations in the beam current, the mechanical design and the corresponding acquisition electronics.

TUPC145	Vibration and Beam Motion Monitoring in TLS	EPICS, controls, monitoring, brilliance	1365
	Y.K. Chen, J. Chen, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	Due to asynchronous nature of various vibration and beam motion related subsystems, it is hard to analysis the correlation between them. Therefore, the synchronous distributed data acquisition system is designed to make an improvement for better analysis. For different circumstances, the system supports two data flow: one is display the real-time data which could be archived continuously and the other is waveform which could be acquired on demand or triggered by event with high sampling rate. In addition, the viewer will improve some useful features, such as trigger by customize signal or EPICS PV record, automatic screenshot and plot the multiple history events. The preliminary test results and implementation details will be summarized in this report.

TUPC148	Measuring Emittance with the MICE Scintillating Fibre Trackers	emittance, simulation, alignment, factory	1374
	D. Adey University of Warwick, Coventry, United Kingdom
	The Muon Ionization Cooling Experiment (MICE) aims to measure a 10% reduction in a muon beam emittance to within 0.1%. To achieve this two scintillating fibre trackers will be placed within a 4T solenoidal field. The trackers utilize fibres with a diameter of 350 microns to provide a position resolution of less than 0.5 mm. Details of the tracker hardware, electronics and its calibration and reconstruction methods will be presented, along with the measured performance under cosmic ray tests and the simulated performance in MICE.

TUPC151	Cherenkov Fibre Optic Beam Loss Monitor at ALICE	beam-losses, laser, electron, monitoring	1383
	A. Intermite The University of Liverpool, Liverpool, United Kingdom A. Intermite, M. Putignano, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The need for real-time monitoring of beam losses, including evaluation of their intensity and the localization of their exact position, together with the possibility to overcome the limitations due to the reduced space for the diagnostics, makes optical fibres (using the Cherenkov Effect) one of the most suitable and explored candidate for beam loss monitoring. In this contribution, we report on an optical fibre beam loss monitor based on large numerical aperture pure silicon fibres and silicon photomultipliers, tested at ALICE, Daresbury Laboratories, UK. The original design of the sensor has the advantage to combine the functions of a real time detector and a transmission line. It also allows reading the signals independently and determining the time and position of the losses without the use of an external trigger.

TUPC152	Comparative Study of Performance of Silicon Photomultipliers for Use in Cherenkov Fibre Optic Beam Loss Monitors	electron, beam-losses, monitoring, lattice	1386
	A. Intermite The University of Liverpool, Liverpool, United Kingdom A. Intermite, M. Putignano, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of Single Photon Avalanche Diodes (SPADs) on a common silicon substrate, working in the limited Geiger mode and with a common readout. The fast counting ability, high timing resolution, immunity to magnetic field up to 15 T, low power consumption and relative small temperature dependence together with the small dimensions make SiPMs excellent candidates as commercially available solid state detectors, and a promising alternative to traditional photomultiplier tubes for single photon detection. Nevertheless, SiPMs do suffer from erroneous counting due to noise effects that can deteriorate their performances. These effects are, in general, heavily dependent on manufacturing quality. In this contribution, results are reported of the characterization of different models of SiPMs in terms of noise spectra and response to light, and a procedure for determining quality manufacturing parameters is described.

TUPC153	Study of the Response of Silicon Photomultipliers in Presence of Strong Cross-talk Noise	beam-losses, radiation, positron, heavy-ion	1389
	M. Putignano, A. Intermite The University of Liverpool, Liverpool, United Kingdom M. Putignano, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by STFC, the EU under GA-ITN-215080, the Helmholtz Association and GSI under VH-NG-328. Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications where they could replace photomultiplier tubes as large dynamic range photon counting devices due to their reduced dimensions and costs, higher photon detection efficiency, immunity to magnetic fields and low operation voltage. Possible applications include longitudinal beam profile measurements by synchrotron light imaging, detection of optical transition radiation for energy spectrum measurements and medical imaging. However, quantitative measurement with SiPMs are jeopardized by the systematic reading error due to Optical Cross-talk (OC), i.e. optical coupling between neighboring diodes in the array. OC results in overestimation of the impinging light level, and reflects the probability of a triggered avalanche creating a photon of suitable energy and direction to fire a second avalanche in another diode. In this paper, we derive a generalized response distribution for SiPM in presence of cross-talk noise, which overcomes the limitations of assumptions currently made in literature and provides a correction of the SiPM response distribution valid for arbitrary large levels of cross-talk.

TUPC158	Micron-scale Laser-wire at the ATF-II at KEK Commissioning and Results	laser, electron, optics, diagnostics	1401
	L.J. Nevay, G.A. Blair, S.T. Boogert, L. Corner, L.C. Deacon, V. Karataev, R. Walczak JAI, Oxford, United Kingdom A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	We present the first results from the commissioning of the upgraded laser-wire experiment at the Accelerator Test Facility 2 (ATF2) at KEK. A new laser transport line and beam diagnostics were used to collide 150 mJ, 167 ps long laser pulses with 1.28 GeV, 30 ps long electron bunches to measure the vertical transverse size. Additionally, a new detector was installed with a reduced area for lower background. Initial scans showing a convoluted beam size of 19.2 ± 0.2 microns were used to tune the electron beam optics and reduce this down to 8.1 ± 0.1 microns. Laser pulse energy and charge dependency were investigated showing a linear relationship in both with a minimum laser energy of 20 mJ required for observable signal with this laser and setup.

TUPC160	Recent Developments of Diagnostics at Diamond	feedback, synchrotron, undulator, diagnostics	1407
	G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas Diamond, Oxfordshire, United Kingdom
	This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO008	Electron Linac Optimization for Driving Bright Gamma-ray Sources based on Compton Back-scattering	electron, linac, laser, emittance	1461
	L. Serafini, F. Broggi, C. De Martinis, D. Giove Istituto Nazionale di Fisica Nucleare, Milano, Italy D. Alesini, P. Antici, A. Bacci, M. Bellaveglia, R. Boni, E. Chiadroni, G. Di Pirro, A. Esposito, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, B. Spataro, P. Tomassini, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy C. Maroli, V. Petrillo Universita' degli Studi di Milano, Milano, Italy M. Migliorati, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy
	We study the optimal lay-out and RF frequency for a room temperature GeV-class Electron Linac aiming at producing electron beams that enhance gamma-ray sources based on Compton back-scattering. These emerging novel sources, generating tunable, mono-chromatic, bright photon beams in the range of 5-20 MeV for nuclear physics as well as nuclear engineering, rely on both, high quality electron beams and J-class high repetition-rate synchronized laser systems in order to achieve the maximum spectral density of the gamma-ray beam (# photons/sec/eV). The best option among the conventionally used RF linac-bands (S, C, X) and possible hybrid schemes will be analyzed and discussed, focusing the study in terms of best performances for the gamma-ray source, its reliability and compactness. We show that the best possible candidates for a Gamma-ray driver are quite similar to those of FEL Linacs.

TUPO013	Development of Pulse Width Measurement Techniques in a Picosecond Range of Ultra-short Gamma Ray Pulses	laser, electron, storage-ring, scattering	1473
	Y. Taira, M. Hosaka, K. Soda, N. Yamamoto Nagoya University, Nagoya, Japan M. Adachi, M. Katoh, H. Zen Sokendai - Okazaki, Okazaki, Aichi, Japan T. Tanikawa UVSOR, Okazaki, Japan
	Funding: This work was supported by Grants-in-Aid for Scientific Research from Japan Society for the Promotion of Science (JSPS). We are developing the ultra-short gamma ray pulse source with the energy of MeV region based on laser Compton scattering at the 750 MeV electron storage ring, UVSOR-II. Gamma rays with pulse width of sub-picosecond range can be generated by injecting femtosecond laser pulses into the electron beam from the vertical 90-degree direction* because the electron beam circulating in the storage ring is focused more tightly in the vertical direction than in the longitudinal direction. The energy, intensity, and pulse width of the gamma rays can be tuned by changing the collision angle between the electron beam and the laser. We are developing pulse width measurement techniques of ultra-short gamma ray pulses at present. As the first step of the pulse width measurement, we used a fast response photodetector, Geiger-mode APD, the time resolution of which is few hundreds picoseconds. Although we cannot measure the pulse width of the gamma rays with sub-picosecond range using this detector, we could measure the pulse width of the gamma rays as 430 ps or less by measuring the timing of Cherenkov radiations generated from the gamma rays. * Y. Taira et al., Nucl. Instrum. Meth. A, in press, 2010.

TUPO014	High-flux Gamma-ray Generation by Laser Compton Scattering in the SAGA-LS Storage Ring	laser, storage-ring, survey, electron	1476
	T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi SAGA, Tosu, Japan
	We constructed an experimental setup for high-flux gamma-ray generation by laser Compton scattering (LCS) in the SAGA-LS storage ring. The SAGA-LS is a synchrotron radiation (SR) facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring. We employed a CO2 laser having a wavelength of 10.6 micrometer to produce gamma-rays in the few MeV region in conjunction with the SR user time. The LCS gamma-ray up to the maximum energy of 3.5 MeV is generated via head-on collision between the laser photons and the 1.4 GeV stored beam. Since the energy acceptance of the storage ring is well above the maximum gamma-ray energy, the LCS experiment can be performed without reducing the beam lifetime. As a first step for high-flux gamma-ray generation, we use a small 10 W CO2 laser for beam test. The LCS event rate is designed to be 2·10⁸ ph/s with a beam current of 300 mA and a laser power of 10 W. A further increase of the LCS event rate in the order of 10¹0 ph/s is expected when a kW class laser is utilized. We report on the characteristics of the LCS gamma-rays observed in the low current beam test and an experimental result for evaluating the gamma-ray flux at a current of 300 mA.

TUPO024	Precision X-band Linac Technologies for Nuclear Photonics Gamma-ray Sources	gun, electron, laser, scattering	1491
	F.V. Hartemann, F. Albert, S.G. Anderson, C.P.J. Barty, A.J. Bayramian, R.R. Cross, G.A. Deis, C.A. Ebbers, D.J. Gibson, T.L. Houck, R.A. Marsh, M. J. Messerly, S.S.Q. Wu LLNL, Livermore, California, USA C. Adolphsen, A.E. Candel, T.S. Chu, M.V. Fazio, E.N. Jongewaard, Z. Li, C. Limborg-Deprey, T.O. Raubenheimer, S.G. Tantawi, A.E. Vlieks, F. Wang, J.W. Wang, F. Zhou SLAC, Menlo Park, California, USA D. Cutoiu Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest, Romania D. Ighigeanu, M. Toma INFLPR, Bucharest - Magurele, Romania V.A. Semenov UCB, Berkeley, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Nuclear photonics is an emerging field of research requiring new tools, including high spectral brightness, tunable gamma-ray sources; high photon energy, ultrahigh-resolution crystal spectrometers; and novel detectors. This presentation focuses on the precision linac technology required for Compton scattering gamma-ray light sources, and on the optimization of the laser and electron beam pulse format to achieve unprecedented spectral brightness. Within this context, high-gradient X-band technology will be shown to offer optimal performance in a compact package, when used in conjunction with the appropriate pulse format, and photocathode illumination and interaction laser technologies.

TUPS008	The Gas Attenuator Vacuum System of FERMI@Elettra	vacuum, radiation, FEL, electron	1530
	L. Rumiz, D. Cocco, C. Fava, S. Gerusina, R. Gobessi, E. Mazzucco, F. Zudini ELETTRA, Basovizza, Italy M. Zangrando IOM-CNR, Trieste, Italy
	The FERMI@Elettra Free Electron Laser aims to produce a coherent light in the EUV-soft X-ray range employing High Gain Harmonic Generation (HGHG) schemes. The ultrafast, high intensity pulses are delivered to the experimental stations by means of a section called PADReS (Photon Analysis Delivery and Reduction System). Since several experiments need to reduce the FEL radiation intensity without changing the machine parameters, PADReS provides an integrated system to measure and reduce it up to 4 orders of magnitude. It is composed by a windowless gas-filled cell, a gas injection system, a differential pumping system, and the intensity monitors. The gas cell can be filled up to 0.15 mbar of nitrogen and the differential pumping system can keep up over 6 orders of magnitude. The pressure is finely regulated in the ·10^-5 mbar range in the intensity monitor vacuum chamber, almost independently from the gas cell pressure level. The general layout and the performance of the differential pumping system prototype are presented.

TUPS011	Use of NEG Pumps to Ensure Long Term Performances of High Quantum Efficiency Photocathodes	ion, cathode, vacuum, gun	1539
	L. Monaco, P.M. Michelato, D. Sertore INFN/LASA, Segrate (MI), Italy P. Manini, F. Siviero SAES Getters S.p.A., Lainate, Italy
	Laser triggered photo-cathodes are key components of the electron sources of 4th generation light machines. However, they are very sensitive to the vacuum level and its composition. Photo-cathodes are usually prepared in UHV chamber and then transferred, keeping the extreme vacuum condition, to the operation sites. Since transportation/storage may last from several days to weeks, retaining UHV conditions is a fundamental task to the photocathode usage. In this paper the results obtained using a novel pumping approach are given. This approach is based on coupling a 20 l.s⁻¹ ion getter pump with a Capacitorr® D100 Non Evaporable Getter (NEG) pump. Pressure of 2x10-11 mbar was achieved with the NEG pump after 2 days bake-out, as compared to 8x10-10 mbar achieved with the ion pump alone, after 7 days bake-out. Such pressure values were retained even in absence of power, due to the ability of the NEG to remove gases by chemical reaction. Long term monitoring of cathodes QEs was also carried out at different photon wavelengths over more than 6 months, showing no degradation of the photo-emissive film properties.

TUPS015	ALBA Storage Ring Vacuum System Commissioning	vacuum, storage-ring, cavity, synchrotron	1551
	E. Al-dmour, D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA booster and storage ring vacuum system installation has been done in 2009, followed by the installation of the RF cavities and the booster to storage transfer line in 2010. Early 2011, the first phase of insertion devices (ID) installation took place, with three narrow gap NEG coated vacuum chambers have been installed, for the use of two Apple-II undulators and one conventional wiggler. On 8th of March 2011, the storage ring commissioning started and it was marked with the achievement of the first turn in the storage ring on the 9th of March and on the 1st of April 2011, 100 mA of beam current has been accumulated. During this period the vacuum system conditioning took place with very good performance. The base pressure without beam was 4·10^-10 mbar and the average pressure with 100 mA was 7.7·10^-9 mbar. The results of the conditioning together with the latest developments are introduced.

TUPS019	Synchrotron Radiation in the LHC Vacuum System	vacuum, dipole, radiation, proton	1563
	V. Baglin, G. Bregliozzi, J.M. Jimenez, G. Lanza CERN, Geneva, Switzerland
	CERN is currently operating the Large Hadron Collider (LHC) with 3.5 TeV per beam. At this energy level, when the protons trajectory is bent, the protons emit synchrotron radiation (SR) with a critical energy of 5.5 eV. Under operation, SR induced molecular desorption is routinely observed in the LHC arcs, long straight sections and experiments. This contribution recalls the SR parameters over the LHC ring for the present and nominal beam parameters. Vacuum observations during energy ramp, after accumulation of dose and along the LHC ring are discussed. Expected pressure profiles and long term behaviours of vacuum levels will be also addressed.

TUPS030	Manufacturing and Vacuum Testing of Aluminum Bending Chambers for TPS	vacuum, ion, synchrotron, electron	1596
	Y.C. Yang, C.K. Chan, C.-C. Chang, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, T.Y. Lee NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS) is an aluminum alloy vacuum system with 518.4 m circumference divided into 24 sections. A6061T6 aluminum alloy material is used for TPS bending chambers. Each aluminum bending chamber is component of 2 half plates, about 3.5～4.2 m in length and～0.6 m in width, were oil-free CNC machined, ozone cleaned, and TIG welding in clean room. The deformation < 0.1 mm and leakage rate < 2x10-9mbar. L/s for each welded bending chamber has inspected and achieved. A bending chamber is inspecting the thermal outgassing rate test and ultimate pressure. The manufacturing and vacuum test will be described in this paper.

TUPS031	The Installation of One 14 Meter Cell of TPS Vacuum System	vacuum, laser, synchrotron, site	1599
	H.P. Hsueh, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, G.-Y. Hsiung, S-N. Hsu, I.T. Huang, T.Y. Lee, H.Y. Yan, Y.C. Yang, C.S. huang NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	The construction of a new 3 GeV synchrotron facility, Taiwan Photon Source, is ongoing. The vacuum system has been designed with off-site baking for arc section from sector gate valve to sector gate valve. There is no flange used in this arc section besides the two ends connected to sector gate valves. It is a tedious works for install such long vacuum system with aluminum chambers. In this poster, all the detailed installation procedures will be described. All the precaution inspection procedures for all vacuum components to prevent failed components to be installed will also be described. Every three weeks, one cell will be assembled and stored. Experience is being learned and could be used for the vacuum system of future new accelerator like FEL and others.

TUPS045	IFMIF/EVEDA Beam Dump Shielding: Optimized Design of the Front Part	shielding, radiation, neutron, diagnostics	1635
	M. García, D. Lopez, A. Mayoral, F. Ogando, J. Sanz, P. Sauvan UNED, Madrid, Spain J.M. Arroyo, B. Brañas CIEMAT, Madrid, Spain
	The Beam Dump of the IFMIF/EVEDA accelerator prototype, designed to stop deuteron beam with energy up to 9 MeV and a maximum beam power of 1.12 MW, needs to fulfill radioprotection requirements. The deuteron beam collides with the beam stop and neutron and photon sources are produced. The objective of this paper is to design and justify the front part of the local shielding of the Beam Dump that complies with radiation limits for workers during beam-off phases. This shielding must allow unrestricted maintenance operations inside the vault, where the accelerator is located, after a reasonable cooling time after shutdown. In doing so, two main handicaps have been overcome. On one hand, the reliability of the traditionally used Monte Carlo codes such as MCNPX and PHITS has demonstrated to be very poor for deuteron transport at these low energies. In order to solve this lack, the MCUNED code using TENDL library is proposed to be used for deuteron transport and the prediction of the neutron and photon sources. On the other hand, the lack of space in the area dedicated to the last part of the accelerator demands a specially optimized shielding solution.

TUPS065	Design of the De-ionized Water Treatment for Taiwan Photon Source	controls, ion, status, storage-ring	1686
	Z.-D. Tsai, W.S. Chan, C.K. Kuan NSRRC, Hsinchu, Taiwan
	This work presents the water treatment design of Taiwan Photon Source (TPS). The system design is influenced by supplied water quality, water quantity and the selected process scheme. The system is composed of a pretreatment, make-up, and points-of-use filtration systems. The pretreatment system consists of an active carbon tower, a normally cartridge filter and a reversed osmosis (RO) unit. Furthermore, the make-up system consists of an ultraviolent (UV) TOC reduction unit and a ion-exchange resin unit. Following the water treatment process, the proposed system can provide high quality de-ionized water whose resistivity is better than 10 MΩ-cm at 25±0.1 degree C and dissolved oxygen is less than 10 ppb.

TUPS066	Design of Front End Safety Interlock System for Taiwan Photon Source	controls, radiation, status, vacuum	1689
	H.Y. Yan, J.-R. Chen, G.-Y. Hsiung, C.K. Kuan, I.C. Sheng, Z.-D. Tsai NSRRC, Hsinchu, Taiwan
	Safety interlock is one of critical subsystems in synchrotron radiation accelerator. A front end (FE) interlock prototype system has been designed, fabricated, and initially tested for Taiwan Photon Source (TPS). TPS FE interlock logic is designed based on that of Taiwan Light Source (TLS), and moderately modified due to the accelerator parameter discrepancy between TPS and TLS. The programmable automation controllers (PAC) have been utilized in FE safety interlock system for their reliability, convenience, processing capability, communication, and stability in user interface. In FE PAC system, touch panels are used as the graphical user interface (GUI) to control and monitor FE components. In addition, with GUI control it is used to beam position monitoring devices as well as confined beam sizes aperture for beam line users. The interlock design such as data acquisition and parameters monitoring for vacuum pressure, flow rate of cooling water, pressure of compressive air, chamber and water temperature, and overall interlock logic are also presented in this paper.

TUPS067	Photon-stimulated Desorption Experiment for a TPS Crotch Absorber	synchrotron, simulation, vacuum, radiation	1692
	Y.T. Cheng, G.-Y. Hsiung, C.K. Kuan, A. Sheng, H.Y. Yan NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC) is constructing a large third-generation synchrotron accelerator in Taiwan, the so-called Taiwan Photon Source (TPS). This 3-GeV, 500-mA machine will generate high-density bending-magnet radiation, of which 90 % of the power is absorbed by the crotch absorber in the storage ring. To understand better the beam-cleaning and photon-desorption phenomena of a copper crotch absorber, we have performed a PSD (photon-stimulated desorption) test in Taiwan Light Source (TLS) at Beam line 19 (BL19). Some mathematical modelling, experimental designs and results are also presented here.

TUPS073	Top-Up Safety Simulations for the TPS Storage Ring	storage-ring, quadrupole, electron, sextupole	1707
	H.-J. Tsai, C.C. Chiang, P.J. Chou, C.-C. Kuo NSRRC, Hsinchu, Taiwan
	TPS is a 3 GeV third generation light source and operates in the top-up injection scheme. During the top-up injection, the beamline photon shutters are always open. To ensure the radiation safety of beamline experiments, we studied the possible particle leakage to ID and neighboring bending beamlines. The effects of errors on magnets and beam chamber alignments are investigated.

WEXA01	Challenges of 4th Generation Light Sources	FEL, electron, emittance, undulator	3798
	C. Pellegrini SLAC, Menlo Park, California, USA C. Pellegrini UCLA, Los Angeles, California, USA
	In the last few years Free Electron Lasers (FELs) have emerged as exceptionally exciting tools for new science. The results from FLASH (Hamburg) on biological imaging, LCLS (Stanford) which generated the first hard X-ray lasing and the projects proposed or in costruction around the world are rapidly moving the scientific community to the so called “fast science” which demands ultrashort pulses, fs synchronization, high brightness, high coherence X-rays. The basic SASE FEL process used so far converts energy jitter into jitter of the centralwavelength. Processes based on seeding and HGHG seem to offer a number of advantages in terms of bandwidth, coherence, stability and undulator length. This talk will present an overview of the 4th generation light sources, discussing the main challenges afforded in the construction of the operating facilities and considering the trends for the development of future facilities.
	Slides WEXA01 [10.640 MB]

WEOBB01	Sub-micrometer Resolution Transverse Electron Beam Size Measurement System based on Optical Transition Radiation	electron, radiation, background, extraction	1964
	A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan S.T. Boogert, V. Karataev JAI, Egham, Surrey, United Kingdom D. Howell Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Optical Transition Radiation (OTR) appears when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The resolution of the conventional monitors is defined by the Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. For small electron beam dimensions, the PSF form significantly depends on various parameters of the optical system like diffraction of the OTR tails, spherical and chromatic aberrations, etc. In our experiment we managed to create a system which can practically measure the PSF distribution and using a new self-calibration method we are able to calculate transverse electron beam size. Here we represent the development, data analysis and novel calibration technique of a sub-micrometer electron beam profile monitor based on the measurements of the PSF shape, which OTR visibility is sensitive to micrometer electron beam dimensions.
	Slides WEOBB01 [2.506 MB]

WEPC052	Spinor Based Calculation of Depolarizing Effects in Circular Lepton Accelerators	synchrotron, resonance, polarization, lepton	2130
	O. Boldt, A. Dieckmann, F. Frommberger, W. Hillert ELSA, Bonn, Germany
	Funding: BMBF The emission of synchrotron radiation strongly influences the beam dynamics in case of ultra relativistic leptons. When storing or accelerating leptons in circular accelerators, the acting magnetic field shows an oscillating behavior in the rest frame of the leptons. Its properties can be determined by a spectral analysis. The stochastic emission of synchrotron light leads to a line broadening within the magnetic field spectrum. This spectrum can be used to simulate depolarizing effects in circular accelerators. Our contribution will present a tracking based calculation of the mentioned spectrum and a spinor-based determination of the resulting population of the spin-up state. These calculations base on the lattice of the electron stretcher accelerator (ELSA, Bonn) and are confirmed by measurements of the polarization.

WEPC134	Unified Accelerator Modeling Using the Bmad Software Library	simulation, lattice, controls, linac	2310
	D. Sagan, I.V. Bazarov, J.Y. Chee, J.A. Crittenden, G. Dugan, K. Finkelstein, G.H. Hoffstaetter, C.E. Mayes, S. Milashuk, D. L. Rubin, J.P. Shanks CLASSE, Ithaca, New York, USA R. Cope CSU, Fort Collins, Colorado, USA
	Funding: Work supported by the National Science Foundation and by the US Department of Energy under contract numbers PHY-0734867 and DE-FC02-08ER41538. The Bmad software library has proved to be a useful tool for accelerator simulations owing to its modular, object-oriented design. It is now used in a number of design, simulation and control programs at the Cornell Laboratory for Accelerator-based Sciences and Education. Work is ongoing to expand Bmad in a number of directions. One aim is tohave a complete framework in order to simulate Cornell's Energy Recovery Linac from Gun cathode (including space-charge) to photon generation to photon tracking through to the x-ray experimental end stations. Other work includes synchrotron radiation tracking including reflections from the vacuum chamber walls which is useful for electron cloud investigations, spin tracking, beam break-up instability, intra-beam scattering, etc. This paper will discuss the current state of the Bmad software along with the long-term goals.

WEPC135	Recent Developments in Modeling Time-resolved Shielded-pickup Measurements of Electron Cloud Buildup at CESRTA	vacuum, electron, radiation, pick-up	2313
	J.A. Crittenden, Y. Li, X. Liu, M.A. Palmer, J.P. Sikora CLASSE, Ithaca, New York, USA R.P. Badman Syracuse University, Syracuse, USA S. Calatroni, G. Rumolo CERN, Geneva, Switzerland S. Kato KEK, Ibaraki, Japan
	Funding: Work supported by the U.S. National Science Foundation PHY-0734867, PHY-1002467 and the U.S. Department of Energy DE-FC02-08ER41538 The Cornell Electron Storage Ring Test Accelerator program includes investigations into the mitigation of electron cloud buildup using a variety of techniques in custom vacuum chambers. The CESR ring accommodates two such chambers equipped with BPM-style pickup detectors shielded against the direct beam-induced signal. The signals provide time-resolved information on cloud development. Results for diamond-like carbon, amorphous carbon, and TiN coatings have been compared to those for an uncoated aluminum chamber. Here we report on extensions to the ECLOUD modeling code which refine its description of a variety of new types of in situ vacuum chamber comparisons. Our results highlight the sensitivity afforded by these measurements to the modeled photoelectron production and secondary yield parameters. We draw conclusions comparing the photoelectron and secondary yield properties of the various vacuum chamber coatings, including conditioning effects as a function of synchrotron radiation dose. We find substantial conditioning effects in both the quantum efficiency for producing photoelectrons and in the secondary yield.

WEPC141	Application of the SYNRAD3D Photon-Tracking Model to Shielded Pickup Measurements of Electron Cloud Buildup at CesrTA	scattering, electron, simulation, vacuum	2319
	L.E. Boon Purdue University, West Lafayette, Indiana, USA J.A. Crittenden, T. Ishibashi CLASSE, Ithaca, New York, USA K.C. Harkay ANL, Argonne, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. We present calculations of synchrotron radiation photon reflection in the vacuum chamber at the Cornell Electron Storage Ring Test Accelerator (CesrTA), applying them as input to the electron cloud buildup code ECLOUD to model time-resolved local measurements with shielded pickup detectors. The recently developed SYNRAD3D photon-tracking code employs a reflection model based on data from the Center for X-Ray Optics at LBNL. This study investigates the dependence of electron cloud buildup on the azimuthal position and kinetic energy distribution of photoelectron production on the vacuum chamber wall.

WEPC169	BPM System Interlock for Machine Protection at SOLEIL	undulator, vacuum, power-supply, electron	2379
	J.-C. Denard, C. Herbeaux, M. Labat, V. Leroux, A. Loulergue, J.L. Marlats SOLEIL, Gif-sur-Yvette, France
	SOLEIL, a third generation light source, has its Beam Position Monitors (BPM) processed by the LIBERA electronics built by Instrumentation Technologies. This electronics initiated and specified by SOLEIL features a fast hardware interlock output for machine protection. Although interlocks are available in both horizontal and vertical planes, it was initially thought that only the vertical interlocks would be useful. Actually, the high photon beam power densities (up to 1kW/mm2) generated by the in-vacuum undulators could damage vacuum chamber elements in case of corrector power supply failures in horizontal or vertical plane. Crotch absorbers, XBPMs and their upstream absorbers were designed on the basis that they will be protected with interlock thresholds not tighter than ±1mm. This approach was also applied for specifying the apertures of the XBPMs and of their upstream absorbers. More recently tracking simulation has shown that the crotch absorber apertures downstream the new canted undulators needed special attention.

WEPC171	Requirements of a Beam Loss Monitoring System for the CLIC Two Beam Modules	beam-losses, linac, simulation, monitoring	2385
	S. Mallows The University of Liverpool, Liverpool, United Kingdom E.B. Holzer, A.P. Mechev, J.W. van Hoorne CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	he Compact Linear Collider (CLIC) study investigates the feasibility of a high-energy electron-positron linear collider optimized for a centre of mass energy of 3 TeV. To achieve the high accelerating gradients, the RF power is produced by a novel two-beam acceleration method in which a decelerating drive beam supplies energy to the main accelerating beam. The linacs are arranged in modular structures referred to as the two beam modules which cover 42 km of beamline. Beam losses from either beam can have severe consequences due to the high intensity drive beam and the high energy, small emittance main beam. This paper presents recent developments towards the design of a Cherenkov fiber BLM system and discusses its ability to distinguish losses originating from either beam.

WEPZ011	Fast Cooling of Bunches in Compton Storage Rings	laser, electron, emittance, scattering	2790
	E.V. Bulyak NSC/KIPT, Kharkov, Ukraine J. Urakawa KEK, Ibaraki, Japan F. Zimmermann CERN, Geneva, Switzerland
	We propose an enhancement of laser radiative cooling by utilizing laser pulses of small spatial and temporal dimensions, which interact only with a fraction of an electron bunch circulating in a storage ring. We studied the dynamics of such electron bunch when laser photons scatter off the electrons at a collision point placed in a section with nonzero dispersion. In this case of ‘asymmetric cooling', the stationary energy spread is much smaller than under conditions of regular scattering where the laser spot size is larger than the electron beam; and the synchrotron oscillations are damped faster. Coherent oscillations of large amplitude may be damped within one synchrotron period, so that this method can support the rapid successive injection of many bunches in longitudinal phase space for stacking purposes. Results of extensive simulations are presented for the performance optimization of Compton gamma-ray sources and damping rings.

THPC001	Progress Towards Implementation of Top-up at the Australian Synchrotron	injection, radiation, storage-ring, interlocks	2904
	G. LeBlanc, P. Bennetto, M.J. Boland, S. Costantin, R.T. Dowd, Y.E. Tan, D. Zhu, E.D. van Garderen ASCo, Clayton, Victoria, Australia
	The Australian Synchrotron Light Source has enjoyed several years of stable operations with a high degree of availability. It is now time to move towards top-up operations to improve the stability and integrated flux of the photon beam. This paper describes the steps that have been taken and what remains to be done in order to implement top-up injection as the normal operation mode for the first user runs of 2012.

THPC021	Status of Bunch Deformation and Lengthening Studies at the ANKA Storage Ring	radiation, diagnostics, cavity, storage-ring	2951
	N. Hiller, A. Hofmann, E. Huttel, V. Judin, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller 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. At the ANKA storage ring (Karlsruhe, Germany) we use a Hamamatsu synchroscan streak camera to study the current dependent bunch lengthening and deformation effects . Previously the camera was used at an IR port, being available only occasionally. In October 2010, a dedicated “beam line” for the streak camera became operational. It is designed to have minimum dispersion and sufficient flux in the optical range at which the camera is most sensitive. This allows us to measure bunch profiles for a single bunch with a charge of less than 15 pC (40 μA), previously more than 55 pC were required to obtain a comparable signal. Along with the design and built-up, we present further measurements of bunch length and shape for different momentum compaction factors, RF voltages, beam energies and bunch charges to provide a complete bunch length map of the low alpha mode at ANKA.

THPC044	Operation and Performance Upgrade of the Soleil Storage Ring	undulator, vacuum, storage-ring, feedback	3002
	A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC052	Progress Towards Top-up Operation at SSRF	injection, storage-ring, radiation, controls	3008
	Z.T. Zhao, H.H. Li, L. Yin, W.Z. Zhang SINAP, Shanghai, People's Republic of China
	The Shanghai Synchrotron Radiation Facility (SSRF) has been in operation for user experiments in decay mode since May 2009. In the meantime various activities to prepare top-up operation at SSRF, including safety analysis and simulation, dedicated instrumentations and interlocks, control software, radiation measurements, injection optimization and top-up operation tests, have been carried out. In this paper, the progress towards top-up operation at SSRF is described together with its achieved performance.

THPC055	Front Ends at ALBA	vacuum, radiation, synchrotron, undulator	3017
	J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC071	Study of the Possibility of Implementing a Superbend in the Diamond Light Source	dipole, vacuum, radiation, magnet-design	3059
	R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.

THPC080	Making Engineering Data Available at the European XFEL	cavity, cryogenics, survey, LLRF	3077
	L. Hagge, J. Bürger, J.A. Dammann, S. Eucker, A. Herz, J. Kreutzkamp, S. Panto, S. Sühl, D. Szepielak, N. Welle DESY, Hamburg, Germany
	One of the essential success factors for the European XFEL is up-to-date, complete and consistent engineering data which is readily accessible throughout the project. Such data include for example civil construction drawings of tunnels and buildings; integrated 3D models of accelerator sections; definitions of fabrication processes and test procedures; inspection sheets, test data, standards, contracts and other technical documentation. The data is kept in the DESY Engineering Data Management System (EDMS). The DESY EDMS is the central information platform for the European XFEL and provides procedures for e.g. review & approvals and change management. The poster presents an overview of Engineering Data Management and its benefits at the European XFEL.

THPC081	Status of the Free-Electron Laser FLASH at DESY	FEL, undulator, laser, radiation	3080
	M. Vogt, B. Faatz, J. Feldhaus, K. Honkavaara, S. Schreiber, R. Treusch DESY, Hamburg, Germany
	The free-electron laser facility FLASH at DESY, Germany has been upgraded in 2010. Now, FLASH delivers an electron beam energy up to 1.25 GeV. The longitudinal phase-space is linearized by 3.9 GHz superconducting cavities. The facility delivers to users ultra-short laser like radiation pulses in the range of less than 50 fs to 200 fs in the soft X-ray wavelenth range from 44 down to 4.1 nm. FLASH provides hundreds to thousands pulses per second to users with unprecedented peak brilliance. FLASH will be upgraded with a second undulator beam line and an additional experimental hall. Construction starts Autumn 2011. We summarize the operational status of the ongoing 3rd user period.

THPC086	Status Report on FERMI@Elettra Project	FEL, linac, electron, undulator	3095
	F. Parmigiani, M. Svandrlik, D. Zangrando ELETTRA, Basovizza, Italy
	Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3 FERMI@Elettra, a single-pass FEL user-facility covering the wavelength range from 100 nm (12 eV) to 3 nm (413 eV) located next to the third-generation synchrotron radiation facility Elettra in Trieste, Italy is actually under completion and will start user operation next year. The first seeded lasing was observed in December 2010 and the first experiments have started this year. In this paper an overview of the present status of machine and beamlines systems will be given as well as a status about operation and future upgrade.

THPC089	Study of a Modified Quasi-periodic Undulator	undulator, radiation, electron, insertion	3104
	A.L. Wu, Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To suppress high-order harmonic radiation effectively while maintain comparatively higher fundamental radiation intensity, a modified quasi-periodic undulator (QPU) which the magnet blocks have different size is studied in this paper. Then the paper also compares the radiation spectrum of various structural schemes. It is shown that the higher harmonic radiation of this new scheme will be suppressed more effectively than the conventional QPU.

THPC102	Production of Coherent Optical \vCerenkov Radiation in Silica Aerogel	radiation, electron, scattering, emittance	3125
	F.H. O'Shea, J.B. Rosenzweig UCLA, Los Angeles, California, USA
	As a demonstration of the apposite properties of silica aerogel as an electron beam diagnostic we intend to use it to produce coherent optical Cˇ erenkov radation (COCR). In this paper we propose an experiment and provide details of the challenges to be overcome in producing COCR.

THPC105	An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source	linac, ion, SRF, FEL	3134
	C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg JLAB, Newport News, Virginia, USA
	Funding: Support by US DoE contract #DE-AC05-060R23177. We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ("afterburner"). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

THPC133	Pre-Conceptual Design Requirements For The MaRIE Facility At LANL And The Resulting X-Ray Free Electron Laser Baseline Design	linac, electron, scattering, emittance	3197
	R.L. Sheffield, B.E. Carlsten LANL, Los Alamos, New Mexico, USA
	The MaRIE (Matter-Radiation Interactions in Extremes) facility is being proposed to advance materials science by the concurrent utilization of a diverse set of highly penetrating probes. These probes will provide the basis for developing materials that will perform predictably and on demand with currently unattainable lifetimes in extreme environments. The MaRIE facilities, the Multi-Probe Diagnostic Hall (MPDH), the Fission and Fusion Materials Facility (F³), and the Making, Measuring, and Modeling Materials (M4) Facility will each have experimental needs for one or more high-energy x-ray beam probes, but all require a 50-keV coherent source of greater than 10¹0 photons in less than 1 ps. Because of space considerations at the facility, a high-gradient design is being investigated that will use a X-band RF systems to drive a 20-GeV normal-conducting linac. Experimental requirements drive a need for multiple photon bunches over time durations greater than 1 microsecond, as well as interleaving 0.1 nC very-low-emittance bunches with 2-nC electron bunches. This paper will cover an overview of the scientific requirements for the MaRIE XFEL and the baseline XFEL design.

THPC150	Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL	vacuum, undulator, brightness, insertion	3236
	O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France
	Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC161	Possible Superconducting Insertion Devices with Period Length Doubling for Beamlines of Third Generation Light Sources	simulation, insertion, insertion-device, undulator	3269
	D. Saez de Jauregui, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, T. Holubek Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	The tunability of an insertion device can be increased by period length switching, which in superconducting insertion devices (IDs) can be achieved by reversing the current in separately powered subsets of the superconducting windings. The feasibility of this concept has been experimentally proven. We study here different possibilities to tailor the needs of beamlines of third generation light sources: FEM simulations performed to compute the magnetic field on axis of such devices with different period lengths are reported together with the spectral simulations.

THPC166	Design Consideration of New Insertion Devices of Hefei Light Source	undulator, vacuum, radiation, insertion	3284
	Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more insertion devices. In this paper the design considerations of new insertion devices are reported, they include one elliptically polarizing undulator, one quasi-periodic undulator, one in-vacuum undulator and one wiggler.

THPC168	Field Error Correction for a Superconducting Undulator	undulator, radiation, electron, simulation	3290
	S. Chunjarean PAL, Pohang, Kyungbuk, Republic of Korea C.-S. Hwang, J.C. Jan NSRRC, Hsinchu, Taiwan H. Wiedemann SLAC, Menlo Park, California, USA
	To reach higher photon energies in the region of soft or hard x-rays with high photon beam brightness in low energy storage rings, superconducting undulators with very short period length and high magnetic field strength are required. Because undulator radiation comes in a line spectrum, photons up to the 7th harmonic are desired. The photon brightness in such harmonics is strongly dependent on perfect periodicity of the magnetic field. Such imperfections also appear in conventional permanent material undulators, which can be corrected by well developed and efficient shimming. Unfortunately, this method cannot be applied to superconducting undulators. Therefore, we present a new approach to field corrections by modification of the magnetic field saturation in each pole. In this paper it is shown that this approach can reduce not only the magnetic field error but also greatly improves phase errors from period to period. The proposed method works quite local with only small perturbations in neighboring poles. The tenability is preserved for most of the field excitations and is reduced only at extreme parameters.

THPC175	Spectral Analysis of Arbitrary Strength Parameter for Various Insertion Devices	undulator, wiggler, insertion, insertion-device	3311
	S.D. Chen, T.M. Uen NCTU, Hsinchu, Taiwan C.-S. Hwang NSRRC, Hsinchu, Taiwan
	An insertion device (ID) with medium strength parameter was hard to be defined as a wiggler or an undulator. Usually, this kind of ID was classified according to the user’s definition and to select the spectrum calculation formula of wiggler or undulator. The spectrum calculation formula for wiggler or undulator is quite difference and consequently obtain a big different flux density by using the same strength parameter. So, it is no way that the spectrum calculation of them is consistent. Therefore, a universal formula will be developed for the spectrum analysis for the different kinds of insertion devices that is with large different strength parameter (deflection parameter). Consequently, a modified spectrum calculation formula of ID with medium strength parameter was studied by reviewing the difference of existing spectrum formulas. The familiar formula of calculating undulator spectrum was modified and can be used on ID with arbitrary strength parameter. The algorithm of formula modification was described. Some relative issue, like the effect of phase error and energy spread, and taper undulator were also discussed herein.

THPC176	Progress in Insertion Devices for TPS in Phase I	undulator, insertion, insertion-device, vacuum	3314
	C.H. Chang, C.-H. Chang, J.C. Huang, C.-S. Hwang, C.K. Yang NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) with beam energy 3 GeV and beam current 500 mA is a third-generation synchrotron radiation facility of medium energy. In the initial commissioning stage of TPS, the machine will be equipped with ten insertion devices (ID) and serve seven beamlines in phase I. Of these, three long straight sections configured as a double-minimum betay function lattice design with minimized beam influence of emittance are used for the installation of a pair of insertion devices in a straight section, two undulators of APPLE-II type and four in-vacuum undulators (IU), to produce great brilliance and coherent X-rays with great flux. The details of these insertion devices are explained herein.

THPC184	Progress of the Coherent Soft X Ray Straight Section at NSLS-II	undulator, electron, polarization, insertion	3329
	C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, D.A. Harder, P. He, Y. Li, C. Meyer, G. Rakowsky, J. Rank, C. Rhein, C.J. Spataro, T. Tanabe BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source II (NSLS-II) is the new light source under construction at Brookhaven National Laboratory (BNL). The Coherent Soft X rays beam line (CSX) is one of the six beamlines included in the baseline project. Following the request of CSX scientists for a source providing adjustable polarized radiation from 160 eV to 1.7 keV, two Advanced Planar Polarized Light Emitter II (APPLE-II)-type undulators will be installed in a 6.6 m long straight section. Each device is 2 m long, the period is 49.2 mm and the minimum gap is 11.5 mm. The different operation modes of the beamline and the layout of the straight section are reviewed here.

THPC186	Heat Load for the APS Superconducting Undulator	radiation, simulation, undulator, shielding	3332
	L.E. Boon, A.F. Garfinkel Purdue University, West Lafayette, Indiana, USA K.C. Harkay ANL, Argonne, USA
	Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The APS Upgrade calls for the development and commissioning of a superconducting undulator (SCU) at the Advanced Photon Source (APS), a 7-GeV electron synchrotron. The first SCU will be installed in June 2012. Until then, simulations such as SYNRAD3D will be used to understand and reduce the heat load on the cryo-system from primary and secondary photons. Current calculations predict that primary photons will distribute 0.5W/m on the chamber walls of the cryostat. SYNRAD3D will be used to calculate the ratio of primary and secondary photons to calculate the heat load due to secondary photons. Previous simulations were of only one sector of the APS accelerator. Simulated here are multiple sectors, to include photons back scattered from downstream photon absorbers.

THPS083	Two-channel Mode of Mo-99 Production at an Electron Accelerator	target, neutron, electron, simulation	3627
	V.L. Uvarov, A.N. Dovbnya, V.V. Mytrochenko, V.I. Nikiforov, S.A. Perezhogin, V.A. Shevchenko, B.I. Shramenko, A.Eh. Tenishev, A.V. Torgovkin NSC/KIPT, Kharkov, Ukraine
	High-energy bremsstrahlung is the main source of isotopic target activation at an electron accelerator. The photoneutrons concurrently generated are generally considered as a background radiation. At the same time, the natural materials entering into photonuclear targets sometimes comprise a mixture of stable isotopes, the atomic-number difference of which equals 2. Thus, if the desired isotope has an intermediate mass, then at certain conditions, it can be produced on two target nuclei at once, via (γ,n) and (n,γ) channels. As an example, we investigate the possibility of increasing the yield of 99Mo by means of its simultaneous production from 100Mo(γ,n)99Mo and 98Mo(n,γ)99Mo reactions. The method and the device have been developed to provide measurements of the 99Mo yield from the natural molybdenum target as it is placed inside the neutron moderator and without the latter. Experiments were performed at the NSC KIPT accelerator LU-40m at electron energies ranging from 30 to 60 MeV. It is demonstrated that the use of the moderator gives nearly a 30% increase in the 99Mo yield. The experimental results are in good agreement with the computer simulation data.

THPS084	Modification of the PENELOPE Transport System for HS Simulation of Isotope Production Mode	target, electron, simulation, radiation	3630
	V.L. Uvarov, V.I. Nikiforov NSC/KIPT, Kharkov, Ukraine
	A method has been developed for high-speed computing the photonuclear isotope yield along with the absorbed radiation power in exit devices of electron accelerator. The technique involves a step-by-step calculation of isotope microyield along the photon trajectories. The approach has been realized in the computer programs based on the PENELOPE system of -2001, -2006 and -2008 versions. For their benchmarking, use has been made of the experimental data on activity distributions of the 67Cu produced from 68Zn(γ,p)67Cu reaction in thick zinc targets. The results of simulation using the PENELOPE-2006 and -2008 codes are in excellent agreement with all experimental data. At the same time, the PENELOPE-2001 computations give good agreement with the experimental results for target activation by the electron beam, but systematically underestimate (~15%) in case of the target exposed to bremsstrahlung. The proposed technique provides a ~ 10⁴ times higher computation speed as compared with the direct Monte Carlo simulation of photonuclear events and that speed is independent of the reaction cross section.

THPS098	Compact Gamma-ray Source for Non-destructive Detection of Nuclear Material in Cargo	laser, microtron, electron, neutron	3663
	R. Hajima JAEA/ERL, Ibaraki, Japan I. Daito, T. Hayakawa, Y. Hayashi, M. Kando, H. Kotaki JAEA, Kyoto, Japan T. Hori, H. Ohgaki Kyoto IAE, Kyoto, Japan N. Kikuzawa JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Shizuma JAEA APRC, Ibaraki-ken, Japan
	Funding: This work is supported by Strategic Funds for Promotion of Science and Technology (Grant No. 066). A mono-energetic gamma-ray source based on laser Compton scattering is under development for non-destructive detection of nuclear material in cargo. In the detection system, we employ nuclear resonance fluorescence triggered by mono-energetic gamma-rays tuned at the resonance energy of nuclear material such as U-235. As a prototype, a 150-MeV microtron combined with a YAG laser to produce a 400-keV gamma ray is constructed at JAEA, where critical technologies are to be demonstrated for high-flux gamma-ray generation, 3x10⁵ ph/s. We also start to design a microtron at higher energy, 250 MeV, to produce a 2-MeV gamma-ray, which is required for the detection of U-235.

THPS099	Design Study of a Nuclear Material Detection System Based on a Quasi Monochromatic Gamma Ray Generator and a Nuclear Resonance Fluorescence Gamma Ray Detection System	neutron, scattering, laser, background	3666
	T. Kii, T. Hori, K. Masuda, H. Ohgaki, M. Omer Kyoto IAE, Kyoto, Japan R. Hajima, T. Hayakawa, M. Kando, T. Shizuma JAEA, Ibaraki-ken, Japan T. Misawa, C.H. Pyeon KURRI, Osaka, Japan H. Toyokawa AIST, Ibaraki, Japan
	Funding: This work was partially supported by Special Coordination Funds for romoting Science and Technology in Japan, Nuclear Resonance Fluorescence (NRF) measurement is a powerful tool for isotope detection for the homeland security such as a nondestructive measurement of containers at airports or harbors and detection or identification of special nuclear materials. In this paper, we will discuss on basic design of a quasi-monochromatic gamma-ray generator based on the backward Compton scattering of laser light on high-energy electrons and an NRF gamma ray detection system using a high-speed scintillation detector.

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MOPO032

The Survey Status at NSRRC during the TPS Civil Construction

survey, alignment, controls, site

553

H.M. Luo, J.-R. Chen, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang
NSRRC, Hsinchu, Taiwan

In this paper, the survey status at NSRRC site duirng the TPS (Taiwan Photon Source) civil construction is described. The TLS (Taiwan Light Source) ring is still under operation in the meantime. In order to maintain the TLS for normal operation and also monitoring the building construction, an expanded survey setups including permanent leveling and GPS monuments were installed both on the site and TPS building. Combined with the orignal TLS survey sockets and sensor monitoring system (hydrostatic leveling system and precision inclination sensors) installed both in the TLS storage ring and beamlines, an extensive survey tasks were performed. The ground deformation situation of the TLS and deviation of the TPS building construction are presented.

MOPO034

From Survey Alignment toward Auto-alignment for the Installation of the TPS Storage Ring Girder System

laser, survey, alignment, controls

559

T.C. Tseng, Chen, M. L. Chen, H.C. Ho, K.H. Hsu, W.Y. Lai, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, H.S. Wang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The TPS (Taiwan Photon Source) project is now under civil construction. The whole building is constructed half underground and 12m deep compared to the TLS due to the stability consideration, so the survey and alignment works are quite confined and difficult. For positioning the magnets precisely and quickly, a high accuracy auto-tuning girders system combined with survey network procedures were established to accomplish the installation tasks. The position data from the survey network will define a basis for the motorized girder system to auto-tune and improve the accuracy. A mockup of one twenty-fourth section (one cell) had been installed at NSRRC for interface examination and further testing. In this paper, the procedures from the traditional survey network to auto-aliment system design and algorithm are described. Meanwhile, a preliminary testing result is also included.

MOPO043

Applications of Lasers to Accelerator Physics at SSRL

laser, gun, cathode, electron

580

D.L. Robinson
Cal Poly, San Luis Obispo, California, USA
W.J. Corbett
SLAC, Menlo Park, California, USA

Recent advances in accelerator physics and SR research have generated the need for high-power lasers in the SPEAR3 accelerator complex. On the injector side, two lasers are being used to test different photocathode materials and to provide photo-assisted emission from the standard dispenser cathode RF gun. For the storage ring, both a TiSa oscillator and a fiber laser locked to the RF master oscillator have been used to characterize short-pulse electron bunches in cross-correlation experiments. These lasers are also used in SR experiments for pump-probe characterization of materials. In this paper we review the laser-based systems, preliminary results and outlook for the future.

MOPO044

Bunch Length Measurements in Low-Alpha Mode at SPEAR3 with First Time-Resolved Pump/Probe Experiments*

laser, synchrotron, single-bunch, radiation

583

J.S. Wittenberg, A. Lindenberg, A. Miller
Stanford University, Stanford, California, USA
W.J. Corbett, L. Wang
SLAC, Menlo Park, California, USA

Funding: Work sponsored by U.S. Department of Energy Contract DE-AC03-76SF00515, Office of Basic Energy Sciences and SLAC Laboratory Directed Research Development funds (LDRD)
The SPEAR3 synchrotron light source can be operated in low-alpha mode to generate x-ray pulse durations of order 1ps, well below streak camera resolution limits yet accessible by laser/sr cross-correlation measurements. Initial CC tests performed with a 50fs TiSa laser, frequency doubling BBO, photodiode and lock-in amplifier resolved bunch lengths down to about 6ps rms with 85uA single-bunch current. By reconfiguring the experimental setup to utilize a fiber laser, sum frequency generation and single photon counter it is now possible to measure profiles in the 1ps rms range with only 5uA single-bunch current. In this paper we report on the most recent measurements, simulations, modeling efforts and prospects for further improvement.

MOPS050

Electron Beam Dynamics in the 50 MeV ThomX Compact Storage Ring

electron, emittance, scattering, collective-effects

715

C. Bruni, J. Haissinski
LAL, Orsay, France
A. Loulergue, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

ThomX is a high flux compact X-ray source based on Compton back scattering between a relativistic electron beam and an intense laser pulse. To increase the repetition rate, the electron beam is stored in a ring. The main drawback of such a scheme is the low energy of the electrons regarding collective effects and intrabeam scattering. These effects tend to enlarge or even disrupt the stored bunch and they limit its charge, especially in a system where damping plays a negligible role. Thus such collective effects reduce the maximum X-ray flux and it is important to investigate them to predict the performance of this type of X-ray source. In addition, the Compton back scattering acts on the electron beam by increasing its energy spread. This presentation will show firstly the impact of collective effects on the electron beam, essentially during the first turns when they are the most harmful. Then, the reduction of the X-ray flux due to Compton back scattering and intrabeam scattering will be investigated on a longer time scale.

MOPS083

Update on Electron Cloud Mitigation Studies at Cesr-TA*

electron, wiggler, positron, resonance

796

J.R. Calvey, M.G. Billing, J.V. Conway, G. Dugan, S. Greenwald, Y. Li, X. Liu, J.A. Livezey, J. Makita, R.E. Meller, M.A. Palmer, S. Santos, R.M. Schwartz, J.P. Sikora, C.R. Strohman
CLASSE, Ithaca, New York, USA
S. Calatroni, G. Rumolo
CERN, Geneva, Switzerland
K. Kanazawa, Y. Suetsugu
KEK, Ibaraki, Japan
M.T.F. Pivi, L. Wang
SLAC, Menlo Park, California, USA

Funding: Work supported by the US National Science Foundation (PHY-0734867) and Department of Energy (DE-FC02-08ER41538)
Over the course of the past three years, the Cornell Electron Storage Ring (CESR) has been reconfigured to serve as a test facility for next generation particle accelerators. A significant part of this program has been the installation of several diagnostic devices to measure and quantify the electron cloud effect, a potential limiting factor in these machines. In particular, more than 30 Retarding Field Analyzers (RFAs) have been installed in CESR. These devices measure the local electron cloud density and energy distribution, and can be used to evaluate the efficacy of different cloud mitigation techniques. This paper will provide an overview of RFA results obtained at CesrTA over the past year, including measurements taken as function of bunch spacing and wiggler magnetic field. Understanding these results provides a great deal of insight into the behavior of the electron cloud.

TUZA01

Commissioning and Initial Operation of FERMI@Elettra

FEL, electron, laser, undulator

918

S. Di Mitri, E. Allaria, R. Appio, L. Badano, S. Bassanese, F. Bencivenga, A.O. Borga, M. Bossi, E. Busetto, C. Callegari, F. Capotondi, K. Casarin, D. Castronovo, P. Cinquegrana, D. Cocco, M. Cornacchia, P. Craievich, R. Cucini, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, P. Delgiusto, A.A. Demidovich, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, S. Ferry, V. Feyer, L. Fröhlich, P. Furlan Radivo, G. Gaio, F. Gelmetti, L. Giannessi, R. Gobessi, R. Ivanov, E. Karantzoulis, M. Kiskinova, M. Lonza, A.A. Lutman, C. Masciovecchio, R.H. Menk, M.M. Milloch, M.M. Musardo, I. Nikolov, S. Noe, F. Parmigiani, L. Pavlovič, E. Pedersoli, G. Penco, M. Petronio, M. Predonzani, E. Principi, E. Quai, G. Quondam, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Wang, M. Zaccaria, D. Zangrando
ELETTRA, Basovizza, Italy
M. Alagia, A. Kivimaki, M. Zangrando, M. de Simone
IOM-CNR, Trieste, Italy
L. Avaldi, P. Bolognesi, M. Coreno, P. O’Keeffe
CNR - IMIP, Trieste, Italy
M. Dal Forno
DIEIT, Trieste, Italy
G. De Ninno, S. Spampinati
University of Nova Gorica, Nova Gorica, Slovenia
M. Devetta, T. Mazza, P. Piseri
Università degli Studi di Milano, Milano, Italy
E. Ferrari
Università degli Studi di Trieste, Trieste, Italy
S. Stranges
Università di Roma "La Sapienza", Roma, Italy

Funding: Work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3.
This article describes the design goals of FERMI@Elettra, reports on the goals achieved so far and shows how the facility development has been driven by the new research frontier of ultra-fast, extreme ultra-violet and soft X-ray science. The commissioning phases and first experience with user pilot experiments are presented and discussed.

Slides TUZA01 [13.401 MB]

TUOAB02

Simultaneous Long and Short Bunch Operation in an Electron Storage Ring - a Hybrid Mode based on Nonlinear Momentum Compaction

electron, storage-ring, synchrotron, octupole

945

M. Ries, J. Feikes, A. Jankowiak, P.O. Schmid, G. Wüstefeld
HZB, Berlin, Germany

The generation of short pulses in electron storage rings is driven by different user groups like time resolved x-ray spectroscopy users or users of coherent synchrotron radiation. The required optics and operation conditions to generate this short bunches are worsening the experimental conditions, e.g. strongly reducing the average photon flux, for the regular user. Therefore short bunch operation is usually limited to dedicated user shifts. By controlling higher orders of the momentum compaction factor by higher multipoles it is possible to introduce a hybrid mode and simultaneously supplying long and short bunches*. The Metrology Light Source (MLS) has the means to control these higher orders**, therefore it is an ideal machine to investiate the feasibility of such a hybrid mode. Tracking results and first measurements will be shown.
* D. Robin et al., Proc. of EPAC08, p. 2100-2102, Genoa, Italy (2008).
** J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).

Slides TUOAB02 [7.817 MB]

TUODB01

Progress of the Construction for the TPS Vacuum System

vacuum, impedance, ion, storage-ring

976

G.-Y. Hsiung, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, S-N. Hsu, H.P. Hsueh, I.T. Huang, T.Y. Lee, I.C. Sheng, L.H. Wu, H.Y. Yan, Y.C. Yang, C.S. huang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

Vacuum system for the 3 GeV Taiwan Photon Source (TPS) has been started the construction since 2010. The critical components such as the bellows and gate valves with rf-contact shielding, pulsed magnet kicker ceramic chambers, BPM, crotch absorbers, etc. have been manufactured and tested. Aluminum alloy (Al-) vacuum chambers for the arc-cells have been machined and undergoing the in-house welding. Mass production of the vacuum equipments including the ion gauges, ion pumps, NEG pumps, and gate valves, has been contracted out and partially delivering following the schedule of the cell assembling. Each cell, contains two short Al-straight chambers and two Al-bending chambers, has been started the assembling and on-site welding on the pre-aligned girders in clean room forming an one-piece vacuum vessel about 14 m in length following by the vacuum baking to the ultra-high vacuum. The conceptual design of the vacuum systems for the long straight sections, the concentric booster, and the transport lines, will be addressed. The progress of prototyping development and the status of construction for the TPS vacuum system will be described in this paper.

Slides TUODB01 [35.595 MB]

TUPC001

Simulations of the Interaction Point for TeV-scale e⁺ e− Colliders

electron, simulation, collider, radiation

985

J. Esberg
Aarhus University, Aarhus, Denmark

The design of a detector and post collisional line of a future linear collider calls for detailed knowledge of the beam-beam dynamics at the interaction point. We here describe the implementation and results of new simulation tools in the program GUINEA-PIG. The subjects are direct trident production relevant in the deep quantum-regime, incoherent muon generation, synchrotron radiation from secondary particles and depolarization effects. We choose beam parameters in the range relevant for CLIC and comment on the implications for the design of such a machine.

TUPC005

Evolution of Pressure in Positron Source for Future Linear e⁺e⁻ Collider

target, positron, collider, linear-collider

994

O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva
University of Hamburg, Hamburg, Germany
A.F. Hartin, G.A. Moortgat-Pick, S. Riemann, A. Ushakov
DESY, Hamburg, Germany
A. Schälicke, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Energy deposition in the conversion targets of positron sources for future linear colliders induces an immense thermal load and create pressure waves in the material. This stress could substantially reduce the lifetime of the target or other target materials impinged by the incident intense photon or electron beam. We have studied the evolution of acoustic pressure waves in target materials based on the parameter assumptions for the International Linear Collider (ILC) baseline source. The fluid model is employed by taking into account the target and the incident photon beam parameters. Initial results of these new simulations are presented and compared with earlier studies. Prospects for further studies are outlined.

TUPC006

Production of Highly Polarized Positron Beams*

polarization, undulator, positron, target

997

A. Ushakov, O.S. Adeyemi, V.S. Kovalenko, L.I. Malysheva, G.A. Moortgat-Pick
University of Hamburg, Hamburg, Germany
A.F. Hartin
DESY, Hamburg, Germany
S. Riemann, A. Schälicke, F. Staufenbiel
DESY Zeuthen, Zeuthen, Germany

Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Management", contract number 05H10GUE
Using of polarized electron and positron beams significantly increases the physics potential of future linear colliders. The generation of an intense and highly polarized positron beam is a challenge. The undulator-based positron source located at the end of electron linac is the baseline source for the International Linear Collider. In case of a 250 GeV drive beam energy, an helical undulator with K = 0.92, an undulator period of 11.5 mm and a titanium alloy target of 0.4 radiation length thickness, the average polarization of the generated positrons is relatively low (about 22 percent). In this contribution, the possibilities of increasing the positron polarization have been considered by adjusting the undulator field and selecting those photons and positrons that yield a highly polarized beam. The detailed simulations have been performed with our developed Geant4-based application PPS-Sim*.
* http://pps-sim.desy.de

TUPC027

CLIC Post-Collision Line Luminosity Monitoring

luminosity, simulation, monitoring, feedback

1057

R. Appleby
UMAN, Manchester, United Kingdom
A. Apyan, L.C. Deacon, E. Gschwendtner
CERN, Geneva, Switzerland

The CLIC post collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14 MW to the main beam dump. Full Monte Carlo simulation has been done for the description of the Compact Linear Collider (CLIC) luminosity monitoring at the post collision line. One method of the luminosity diagnostic is based on the detection of high energy muons produced by the beamsstrahlung photons in the main beam dump. The disrupted beam and the beamsstrahlung photons produce at the order of 10⁶ muons per bunch crossing, with energies greater than 10 GeV. Currently threshold Cherenkov counters are considered after the beam dump for the detection of these high energy muons. A second method using the direct detection of the beamsstrahlung photons is also considered.

TUPC028

Background and Energy Deposition Studies for the CLIC Post-Collision Line*

simulation, radiation, positron, electron

1060

R. Appleby, M.D. Salt
UMAN, Manchester, United Kingdom
L.C. Deacon, E. Gschwendtner
CERN, Geneva, Switzerland

The CLIC post-collision line is designed to transport the spent-beam products of collision to their respective dumps, with minimal losses and thus minimal background contributions. With nanometre spot-sizes at TeV energies, large beam-beam effects induce divergence and dispersion of the outgoing beams, with a large production cross-section of Beamstrahlung photons and subsequently coherent pairs. The post-collision line should provide sufficient divergence of the beam to avoid damage to the vacuum exit and dump entrance windows. In this study, the beam losses are investigated, with the production of secondary particles from the interaction with matter simulated. The particle flux leakage from absorbers and dumps is modelled to determine the total energy deposited on magnets of the post-collision line. Finally, both electromagnetic and hadronic backgrounds at the CLIC experiment are considered.

TUPC048

First Measurement Results of the LHC Longitudinal Density Monitor

proton, ion, synchrotron, diagnostics

1105

A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo
CERN, Geneva, Switzerland
A.S. Fisher
SLAC, Menlo Park, California, USA
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The primary author is funded by the E.U. under the DITANET Marie Curie network.
Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, for example to check the injection quality and to characterize the development of ghost bunches before and during the physics periods. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. The LDM is able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 10⁵ to be achieved. The LDM operated during the 2010 lead ion run and during 2011 with protons. Measurements from both runs are presented in this contribution along with an analysis of the LDM performance and an outlook for future upgrades.

TUPC068

SOLEIL Beam Orbit Stability Improvements

feedback, booster, synchrotron, power-supply

1156

N. Hubert, Y.-M. Abiven, F. Blache, F. Briquez, L. Cassinari, J.-C. Denard, J.-F. Lamarre, P. Lebasque, N. Leclercq, A. Lestrade, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

The electron beam orbit stability has been significantly improved at synchrotron SOLEIL. Low frequency noise sources have been localized and identified: the fans installed on the storage ring to cool down the ceramic chambers of the kickers, shaker and FCT, were slightly wobbling the electron beam orbit at 46, 50, 54 and 10⁸ Hz. The localization method and the solutions that will allow reducing the noise from 0.8 μm RMS down to 0.3 μm are presented. Besides, a new 160 m long beamline, NANOSCOPIUM, is being installed on a canted straight section. Its photon beam position stability requirements are very tight calling for the following improvements: addition of 2 more BPMs and fast correctors in the orbit feedback loops, new INVAR stands for BPM and XBPM integrating Hydrostatic Level System sensors. The paper is also discussing other projects that did or will contribute to improving the beam orbit stability: installation of 145 temperature sensors on the storage ring, a new analog feedforward correction system for insertion devices, and the use of the bending magnet X-BPM measurements in the slow and fast orbit feedback loops.

TUPC069

Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL

radiation, undulator, optics, electron

1159

M.-A. Tordeux, F. Dohou, M. Labat, O. Marcouillé
SOLEIL, Gif-sur-Yvette, France

Bunch length measurements can be made by analysing the pulse to pulse intensity fluctuation of the incoherent synchrotron radiation as it has been reported elsewhere*. Such a method has been tested at SOLEIL for picosecond bunch durations, at several wavelengths and bandwidths in the visible range, using an avalanche photodiode. Thanks to the low-alpha optics the lengths of 10 μA bunches as short as 3 ps have been measured in good agreement with the streak camera results. We first used the radiation from a bending magnet, and then from a HU640 undulator that enhances the photon flux. Moreover, taking advantage of using the radiation from an undulator, we show that the method can still be used when the number of spikes emitted by the electron bunch is reduced to a few hundreds. This could be of interest for bunch length measurements of X-ray SASE FELs. Furthermore, we intend to use a single crystal diamond detector in order to perform these measurements in the X-ray range.
* F. Sannibale et al., "Absolute bunch length measurements by incoherent radiation fluctuation analysis", PRST AB 12, 032801 (2009).

TUPC072

Accurate Electron Beam Size Measurement at the Metrology Light Source

electron, radiation, polarization, storage-ring

1165

R. Klein, G. Brandt, R. Thornagel
PTB, Berlin, Germany
J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

For the operation of the Metrology Light Source (MLS)*, the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB), as the national primary radiation source standard from the near infrared to the vacuum ultraviolet spectral region, all storage ring parameters which are relevant for the calculation of the radiant intensity by the Schwinger equation have to be known absolutely with small uncertainties. For the measurement of the effective vertical electron beam size a Bragg polarimeter, operating at a photon energy of 1103 eV, has been designed and put into operation. This system also serves as a detection system for the image of the electron beam through a set of narrow slits. The results obtained with the new device are compared to those measured by an optical beam imaging system**.
* R. Klein et al., Phys. Rev. ST-AB 11, 110701 (2008).
** C. Koschitzki et al., Proc. IPAC10, 894-896 (2010).

TUPC074

A New Counting Silicon Strip Detector System for Precise Compton Polarimetry

electron, polarization, laser, scattering

1171

R. Zimmermann, W. Hillert, J.C. Wittschen
ELSA, Bonn, Germany

Funding: Supported by the German Research Foundation within the SFB/TR16
A Compton polarimeter is currently being installed at the Electron Stretcher Facility ELSA to monitor the degree of polarization of the stored electron beam. For this purpose, circularly polarized light that is emitted by a laser and backscattered off the beam has to be detected. Above all, as a result of ELSA's beam energies, it is necessary to measure the shift of the center of the photon spatial distribution which is obtained when the polarization of the laser is switched from left-hand to right-hand circular polarization with an accuracy of a few microns. In order to meet the required specifications, a new counting silicon strip detector system has been developed in cooperation with the SiLab/ATLAS group of the Physics Institute of the University of Bonn. In this contribution, the design of the system will be presented and first results will be shown.

TUPC081

Diagnostics of Femtosecond Low-charge Electron Bunches at REGAE

electron, diagnostics, laser, simulation

1192

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

A new linac is constructed at DESY as the electron source fo "Relativistic Electron Gun for Atomic Exploration (REGAE)". REGAE is mainly established for a Femtosecond electron diffraction experiment presenting structural information on atomic transition states occurring in the sub-hundred femtosecond time-scale. REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell RF cavity to provide sub pico-Coulomb charge of 2 to 5 MeV energy with a coherent length in the range of 30nm. In order to produce and maintain such high quality electron bunches, sophisticated single-shot diagnostics is mandatory to monitor the properties. Diagnostics include emittance, energy, energy spread and bunch length measurement. In this paper the conceptual ideas and steps toward realization of these diagnostics are presented with a detailed focus on transverse diagnostics. As for photon source of transversal diagnostics, scintillators are studied. Simulation results show which material suits the best for REGAE parameters. Layout of a home-made intensified camera is presented. The method discussed in this paper would also be advantageous for low-charge Free Electron Lasers.

TUPC083

Comparative Studies into 3D Beam Loss Simulations

simulation, beam-losses, electron, positron

1198

M. Panniello
MPI-K, Heidelberg, Germany
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328.
A detailed understanding and monitoring of potential beam loss mechanisms is crucial for every particle accelerator. The main motivation in low energy facilities, such as the Ultra-low energy Storage Ring (USR) at the future Facility of Low energy Antiproton and Ion Research (FLAIR), comes from the very low number of particles available which in such machine ought to be conserved. In High Energy accelerators it is the concern about activation or even physical damage of machine parts which has to be taken into serious account. The CLIC Test Facility (CTF3) at CERN provides an ideal testing ground for studies into novel BLM systems and is well suited for benchmarking the results from numerical simulations in experiments. This contribution summarizes the three-dimensional beam loss pattern as found with the commonly used codes FLUKA and Géant4. The results from these codes are compared and analyzed in detail and used for the identification of optimum beam loss monitor locations.

TUPC087

Filling Pattern Measurements at the ANKA Storage Ring

electron, storage-ring, single-bunch, synchrotron

1209

B. Kehrer, N. Hiller, A. Hofmann, E. Huttel, V. Judin, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale
KIT, Karlsruhe, Germany

For many accelerator physics studies, e.g. the investigation of coherent synchrotron radiation (CSR), a precise knowledge of the quantitative filling pattern (i.e. the number of electrons per bunch) is essential. This can be achieved by either using a linear detector (analog recording) or by employing the method of time-correlated single photon counting (TCSPC). At the ANKA storage ring both methods are in use. The analogue detection is based on the signal from a stripline or annular electrode, the TCSPC uses a Single Photon Avalanche Diode (SPAD). In this paper, we describe the experimental set-ups and present results of a comparison of the two techniques for single as well as for multi bunch filling patterns.

TUPC088

An Ionization Profile Monitor for the Determination of the FLASH and PITZ Beam Parameters

electron, vacuum, diagnostics, ion

1212

J. Mießner, H.-J. Grabosch, M. Markert, R. Sternberger
DESY Zeuthen, Zeuthen, Germany
A. Hofmann
KIT, Karlsruhe, Germany
K.I. Tiedtke
DESY, Hamburg, Germany

To operate FLASH (Free-electron LASer at Hamburg) successfully, accurate measurements of the photon beam parameters, like position and profile, are essential. The development of a specific Ionization Profile Monitor (IPM) is one contribution to the photon beam diagnostics, and currently one horizontal and one vertical oriented IPM are installed at FLASH. The working principle of the IPM is based on the detection of ions generated by interactions of the photon beam with the residual gas, which is always present in the beam line. An essential advantage of this method is that the beam is not influenced by the IPM, so it is possible to analyze the beam parameters without beam destruction. Moreover, the monitor is able to determine the relative position and the spatial profile of the beam with the precision of a few um. In this poster, the design and first measurements with the IPM taken at FLASH are presented. A good measuring accuracy of the IPM is obtained. Moreover, first results of measurements at PITZ (PhotoInjector Testfacility at Zeuthen) are given for one vertical oriented IPM with a up to 25 MeV electron beam.

TUPC112

Photon Beam Position Monitor based on Position-sensitive Detector for HLS*

synchrotron, injection, diagnostics, feedback

1281

Y.Y. Xiao, L.M. Gu, P. Lu, B.G. Sun, L.L. Tang, J.G. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In order to overcome the limitation that the existing photon beam position monitors (PBPM) cannot measure the beam position in vertical and horizontal at the same time, a new photon beam position monitor based on position-sensitive detector (PSD) has developed at HLS (Hefei Light Source). The new PBPM based on the PSD has very fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. Some results are given.

TUPC121

Development of MCP Based Photon Detectors for the European XFEL

radiation, FEL, background, vacuum

1299

E. Syresin, M.N. Kapishin
JINR, Dubna, Moscow Region, Russia
O.I. Brovko, A.V. Shabunov
JINR/VBLHEP, Moscow, Russia
W. Freund, J. Grünert, H. Sinn
European XFEL GmbH, Hamburg, Germany
M.V. Yurkov
DESY, Hamburg, Germany

To provide successful operation of SASE XFEL the radiation detectors should operate in wide dynamic range from the level of spontaneous emission to the saturation level, in wide wavelength range from 0.05 nm to 0.16 nm for SASE1 and SASE2 and from 0.4 nm to 4.4 nm for SASE3. High relative accuracy of measurements is crucial for detection of a signature of lasing, tuning of amplification process, and characterization of statistical properties of the radiation. The XFEL radiation detector based on micro-channel plates (MCP) meets these requirements. Two types of the photon detector are used for measurements of the pulse radiation energy and the image of the photon beam. The dynamic range of photon pulse energies is between 1 nJ and 10 mJ. This applies to spontaneous and FEL radiation. The relative accuracy of pulse energy measurements is better than 1%. The visualization of a single bunch in a train, or average image over the full train will perform by the MCP imager at a spatial resolution of 30 μm.

TUPC124

Laser Wire Emittance Measurement Line at CLIC*

laser, emittance, collider, electron

1308

H. Garcia, Yu.A. Kubyshin
UPC, Barcelona, Spain
T. Aumeyr, G.A. Blair
JAI, Egham, Surrey, United Kingdom
D. Schulte, F. Stulle
CERN, Geneva, Switzerland

A precise measurement of the transverse beam size and beam emittances upstream of the final focus is essential for ensuring the full luminosity at future linear colliders. A scheme for the emittance measurements at the RTML line of the CLIC using laser-wire beam profile monitors is described. A lattice of the measurement line is discussed and results of simulations of statistical and machine-related errors and of their impact on the accuracy of the emittance reconstruction are given. Modes of operation of the laser wire system and its main characteristics are discussed.

TUPC129

A Beam Position System for Hadrontherapy Facilities

electron, controls, vacuum, proton

1323

A. Faus-Golfe, C. Belver-Aguilar, C. Blanch Gutierrez, J.J. García-Garrigós
IFIC, Valencia, Spain
E. Benveniste, M. Haguenauer, P. Poilleux
LLR, Palaiseau, France

Funding: MICINN-FPA:AIC10-D-000518
Essential parts of the needed instrumentation for the beam control in the Hadrontherapy accelerators are the Beam Position Monitors (BPM). The measurement of the beam position in Hadronterapy accelerators become more important at the secondary transport lines towards the patient room where this parameter must be completely determined. The BPM described in this paper is a new type of BPM based on four scintillating fibers coupled to four photodiodes to detect the light produced by the fibers when intercepting the beam. We present here the study of the different photodiodes able to read the light emitted by the scintillating fiber, the tests performed in order to find the most suitable photodiode to measure the beam position from the variations in the beam current, the mechanical design and the corresponding acquisition electronics.

TUPC145

Vibration and Beam Motion Monitoring in TLS

EPICS, controls, monitoring, brilliance

1365

Y.K. Chen, J. Chen, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

Due to asynchronous nature of various vibration and beam motion related subsystems, it is hard to analysis the correlation between them. Therefore, the synchronous distributed data acquisition system is designed to make an improvement for better analysis. For different circumstances, the system supports two data flow: one is display the real-time data which could be archived continuously and the other is waveform which could be acquired on demand or triggered by event with high sampling rate. In addition, the viewer will improve some useful features, such as trigger by customize signal or EPICS PV record, automatic screenshot and plot the multiple history events. The preliminary test results and implementation details will be summarized in this report.

TUPC148

Measuring Emittance with the MICE Scintillating Fibre Trackers

emittance, simulation, alignment, factory

1374

D. Adey
University of Warwick, Coventry, United Kingdom

The Muon Ionization Cooling Experiment (MICE) aims to measure a 10% reduction in a muon beam emittance to within 0.1%. To achieve this two scintillating fibre trackers will be placed within a 4T solenoidal field. The trackers utilize fibres with a diameter of 350 microns to provide a position resolution of less than 0.5 mm. Details of the tracker hardware, electronics and its calibration and reconstruction methods will be presented, along with the measured performance under cosmic ray tests and the simulated performance in MICE.

TUPC151

Cherenkov Fibre Optic Beam Loss Monitor at ALICE

beam-losses, laser, electron, monitoring

1383

A. Intermite
The University of Liverpool, Liverpool, United Kingdom
A. Intermite, M. Putignano, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The need for real-time monitoring of beam losses, including evaluation of their intensity and the localization of their exact position, together with the possibility to overcome the limitations due to the reduced space for the diagnostics, makes optical fibres (using the Cherenkov Effect) one of the most suitable and explored candidate for beam loss monitoring. In this contribution, we report on an optical fibre beam loss monitor based on large numerical aperture pure silicon fibres and silicon photomultipliers, tested at ALICE, Daresbury Laboratories, UK. The original design of the sensor has the advantage to combine the functions of a real time detector and a transmission line. It also allows reading the signals independently and determining the time and position of the losses without the use of an external trigger.

TUPC152

Comparative Study of Performance of Silicon Photomultipliers for Use in Cherenkov Fibre Optic Beam Loss Monitors

electron, beam-losses, monitoring, lattice

1386

A. Intermite
The University of Liverpool, Liverpool, United Kingdom
A. Intermite, M. Putignano, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Silicon Photomultipliers (SiPMs) are semiconductor photo-sensitive devices built from a matrix of Single Photon Avalanche Diodes (SPADs) on a common silicon substrate, working in the limited Geiger mode and with a common readout. The fast counting ability, high timing resolution, immunity to magnetic field up to 15 T, low power consumption and relative small temperature dependence together with the small dimensions make SiPMs excellent candidates as commercially available solid state detectors, and a promising alternative to traditional photomultiplier tubes for single photon detection. Nevertheless, SiPMs do suffer from erroneous counting due to noise effects that can deteriorate their performances. These effects are, in general, heavily dependent on manufacturing quality. In this contribution, results are reported of the characterization of different models of SiPMs in terms of noise spectra and response to light, and a procedure for determining quality manufacturing parameters is described.

TUPC153

Study of the Response of Silicon Photomultipliers in Presence of Strong Cross-talk Noise

beam-losses, radiation, positron, heavy-ion

1389

M. Putignano, A. Intermite
The University of Liverpool, Liverpool, United Kingdom
M. Putignano, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by STFC, the EU under GA-ITN-215080, the Helmholtz Association and GSI under VH-NG-328.
Silicon Photomultipliers (SiPM) are interesting detectors for beam diagnostics applications where they could replace photomultiplier tubes as large dynamic range photon counting devices due to their reduced dimensions and costs, higher photon detection efficiency, immunity to magnetic fields and low operation voltage. Possible applications include longitudinal beam profile measurements by synchrotron light imaging, detection of optical transition radiation for energy spectrum measurements and medical imaging. However, quantitative measurement with SiPMs are jeopardized by the systematic reading error due to Optical Cross-talk (OC), i.e. optical coupling between neighboring diodes in the array. OC results in overestimation of the impinging light level, and reflects the probability of a triggered avalanche creating a photon of suitable energy and direction to fire a second avalanche in another diode. In this paper, we derive a generalized response distribution for SiPM in presence of cross-talk noise, which overcomes the limitations of assumptions currently made in literature and provides a correction of the SiPM response distribution valid for arbitrary large levels of cross-talk.

TUPC158

Micron-scale Laser-wire at the ATF-II at KEK Commissioning and Results

laser, electron, optics, diagnostics

1401

L.J. Nevay, G.A. Blair, S.T. Boogert, L. Corner, L.C. Deacon, V. Karataev, R. Walczak
JAI, Oxford, United Kingdom
A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

We present the first results from the commissioning of the upgraded laser-wire experiment at the Accelerator Test Facility 2 (ATF2) at KEK. A new laser transport line and beam diagnostics were used to collide 150 mJ, 167 ps long laser pulses with 1.28 GeV, 30 ps long electron bunches to measure the vertical transverse size. Additionally, a new detector was installed with a reduced area for lower background. Initial scans showing a convoluted beam size of 19.2 ± 0.2 microns were used to tune the electron beam optics and reduce this down to 8.1 ± 0.1 microns. Laser pulse energy and charge dependency were investigated showing a linear relationship in both with a minimum laser energy of 20 mJ required for observable signal with this laser and setup.

TUPC160

Recent Developments of Diagnostics at Diamond

feedback, synchrotron, undulator, diagnostics

1407

G. Rehm, C. Bloomer, A.F.D. Morgan, C.A. Thomas
Diamond, Oxfordshire, United Kingdom

This contribution summarizes some recent development of diagnostics system to improve the operation of Diamond Light Source. Firstly, we are advancing the integration of photon beam diagnostics with the orbit feedback system. Measurements have shown the correlation between recorded electron and photon beam motion on the short timescales (ms-minutes) and the potential for improvement on long timescales (minutes-days). Secondly, with the addition of more elliptically polarized undulators at Diamond, measurement of their photon beam position require a solution that reliably operates with the changing photon beam profiles emitted by these devices. To this end, we have developed an X-ray beam position monitor that analyzes the backscatter from an aperture in the front end. Thirdly, as operation in low-alpha mode with few ps bunch lengths receives increasing interest from users, we have been evaluating various techniques for the measurement of these short bunch lengths that could serve as alternatives to streak camera measurements.

TUPO008

Electron Linac Optimization for Driving Bright Gamma-ray Sources based on Compton Back-scattering

electron, linac, laser, emittance

1461

L. Serafini, F. Broggi, C. De Martinis, D. Giove
Istituto Nazionale di Fisica Nucleare, Milano, Italy
D. Alesini, P. Antici, A. Bacci, M. Bellaveglia, R. Boni, E. Chiadroni, G. Di Pirro, A. Esposito, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, E. Pace, A.R. Rossi, B. Spataro, P. Tomassini, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
C. Maroli, V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
M. Migliorati, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy

We study the optimal lay-out and RF frequency for a room temperature GeV-class Electron Linac aiming at producing electron beams that enhance gamma-ray sources based on Compton back-scattering. These emerging novel sources, generating tunable, mono-chromatic, bright photon beams in the range of 5-20 MeV for nuclear physics as well as nuclear engineering, rely on both, high quality electron beams and J-class high repetition-rate synchronized laser systems in order to achieve the maximum spectral density of the gamma-ray beam (# photons/sec/eV). The best option among the conventionally used RF linac-bands (S, C, X) and possible hybrid schemes will be analyzed and discussed, focusing the study in terms of best performances for the gamma-ray source, its reliability and compactness. We show that the best possible candidates for a Gamma-ray driver are quite similar to those of FEL Linacs.

TUPO013

Development of Pulse Width Measurement Techniques in a Picosecond Range of Ultra-short Gamma Ray Pulses

laser, electron, storage-ring, scattering

1473

Y. Taira, M. Hosaka, K. Soda, N. Yamamoto
Nagoya University, Nagoya, Japan
M. Adachi, M. Katoh, H. Zen
Sokendai - Okazaki, Okazaki, Aichi, Japan
T. Tanikawa
UVSOR, Okazaki, Japan

Funding: This work was supported by Grants-in-Aid for Scientific Research from Japan Society for the Promotion of Science (JSPS).
We are developing the ultra-short gamma ray pulse source with the energy of MeV region based on laser Compton scattering at the 750 MeV electron storage ring, UVSOR-II. Gamma rays with pulse width of sub-picosecond range can be generated by injecting femtosecond laser pulses into the electron beam from the vertical 90-degree direction* because the electron beam circulating in the storage ring is focused more tightly in the vertical direction than in the longitudinal direction. The energy, intensity, and pulse width of the gamma rays can be tuned by changing the collision angle between the electron beam and the laser. We are developing pulse width measurement techniques of ultra-short gamma ray pulses at present. As the first step of the pulse width measurement, we used a fast response photodetector, Geiger-mode APD, the time resolution of which is few hundreds picoseconds. Although we cannot measure the pulse width of the gamma rays with sub-picosecond range using this detector, we could measure the pulse width of the gamma rays as 430 ps or less by measuring the timing of Cherenkov radiations generated from the gamma rays.
* Y. Taira et al., Nucl. Instrum. Meth. A, in press, 2010.

TUPO014

High-flux Gamma-ray Generation by Laser Compton Scattering in the SAGA-LS Storage Ring

laser, storage-ring, survey, electron

1476

T. Kaneyasu, Y. Iwasaki, S. Koda, Y. Takabayashi
SAGA, Tosu, Japan

We constructed an experimental setup for high-flux gamma-ray generation by laser Compton scattering (LCS) in the SAGA-LS storage ring. The SAGA-LS is a synchrotron radiation (SR) facility consisting of a 255 MeV injector linac and a 1.4 GeV storage ring. We employed a CO2 laser having a wavelength of 10.6 micrometer to produce gamma-rays in the few MeV region in conjunction with the SR user time. The LCS gamma-ray up to the maximum energy of 3.5 MeV is generated via head-on collision between the laser photons and the 1.4 GeV stored beam. Since the energy acceptance of the storage ring is well above the maximum gamma-ray energy, the LCS experiment can be performed without reducing the beam lifetime. As a first step for high-flux gamma-ray generation, we use a small 10 W CO2 laser for beam test. The LCS event rate is designed to be 2·10⁸ ph/s with a beam current of 300 mA and a laser power of 10 W. A further increase of the LCS event rate in the order of 10¹0 ph/s is expected when a kW class laser is utilized. We report on the characteristics of the LCS gamma-rays observed in the low current beam test and an experimental result for evaluating the gamma-ray flux at a current of 300 mA.

TUPO024

Precision X-band Linac Technologies for Nuclear Photonics Gamma-ray Sources

gun, electron, laser, scattering

1491

F.V. Hartemann, F. Albert, S.G. Anderson, C.P.J. Barty, A.J. Bayramian, R.R. Cross, G.A. Deis, C.A. Ebbers, D.J. Gibson, T.L. Houck, R.A. Marsh, M. J. Messerly, S.S.Q. Wu
LLNL, Livermore, California, USA
C. Adolphsen, A.E. Candel, T.S. Chu, M.V. Fazio, E.N. Jongewaard, Z. Li, C. Limborg-Deprey, T.O. Raubenheimer, S.G. Tantawi, A.E. Vlieks, F. Wang, J.W. Wang, F. Zhou
SLAC, Menlo Park, California, USA
D. Cutoiu
Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest, Romania
D. Ighigeanu, M. Toma
INFLPR, Bucharest - Magurele, Romania
V.A. Semenov
UCB, Berkeley, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Nuclear photonics is an emerging field of research requiring new tools, including high spectral brightness, tunable gamma-ray sources; high photon energy, ultrahigh-resolution crystal spectrometers; and novel detectors. This presentation focuses on the precision linac technology required for Compton scattering gamma-ray light sources, and on the optimization of the laser and electron beam pulse format to achieve unprecedented spectral brightness. Within this context, high-gradient X-band technology will be shown to offer optimal performance in a compact package, when used in conjunction with the appropriate pulse format, and photocathode illumination and interaction laser technologies.

TUPS008

The Gas Attenuator Vacuum System of FERMI@Elettra

vacuum, radiation, FEL, electron

1530

L. Rumiz, D. Cocco, C. Fava, S. Gerusina, R. Gobessi, E. Mazzucco, F. Zudini
ELETTRA, Basovizza, Italy
M. Zangrando
IOM-CNR, Trieste, Italy

The FERMI@Elettra Free Electron Laser aims to produce a coherent light in the EUV-soft X-ray range employing High Gain Harmonic Generation (HGHG) schemes. The ultrafast, high intensity pulses are delivered to the experimental stations by means of a section called PADReS (Photon Analysis Delivery and Reduction System). Since several experiments need to reduce the FEL radiation intensity without changing the machine parameters, PADReS provides an integrated system to measure and reduce it up to 4 orders of magnitude. It is composed by a windowless gas-filled cell, a gas injection system, a differential pumping system, and the intensity monitors. The gas cell can be filled up to 0.15 mbar of nitrogen and the differential pumping system can keep up over 6 orders of magnitude. The pressure is finely regulated in the ·10^-5 mbar range in the intensity monitor vacuum chamber, almost independently from the gas cell pressure level. The general layout and the performance of the differential pumping system prototype are presented.

TUPS011

Use of NEG Pumps to Ensure Long Term Performances of High Quantum Efficiency Photocathodes

ion, cathode, vacuum, gun

1539

L. Monaco, P.M. Michelato, D. Sertore
INFN/LASA, Segrate (MI), Italy
P. Manini, F. Siviero
SAES Getters S.p.A., Lainate, Italy

Laser triggered photo-cathodes are key components of the electron sources of 4th generation light machines. However, they are very sensitive to the vacuum level and its composition. Photo-cathodes are usually prepared in UHV chamber and then transferred, keeping the extreme vacuum condition, to the operation sites. Since transportation/storage may last from several days to weeks, retaining UHV conditions is a fundamental task to the photocathode usage. In this paper the results obtained using a novel pumping approach are given. This approach is based on coupling a 20 l.s⁻¹ ion getter pump with a Capacitorr® D100 Non Evaporable Getter (NEG) pump. Pressure of 2x10-11 mbar was achieved with the NEG pump after 2 days bake-out, as compared to 8x10-10 mbar achieved with the ion pump alone, after 7 days bake-out. Such pressure values were retained even in absence of power, due to the ability of the NEG to remove gases by chemical reaction. Long term monitoring of cathodes QEs was also carried out at different photon wavelengths over more than 6 months, showing no degradation of the photo-emissive film properties.

TUPS015

ALBA Storage Ring Vacuum System Commissioning

vacuum, storage-ring, cavity, synchrotron

1551

E. Al-dmour, D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA booster and storage ring vacuum system installation has been done in 2009, followed by the installation of the RF cavities and the booster to storage transfer line in 2010. Early 2011, the first phase of insertion devices (ID) installation took place, with three narrow gap NEG coated vacuum chambers have been installed, for the use of two Apple-II undulators and one conventional wiggler. On 8th of March 2011, the storage ring commissioning started and it was marked with the achievement of the first turn in the storage ring on the 9th of March and on the 1st of April 2011, 100 mA of beam current has been accumulated. During this period the vacuum system conditioning took place with very good performance. The base pressure without beam was 4·10^-10 mbar and the average pressure with 100 mA was 7.7·10^-9 mbar. The results of the conditioning together with the latest developments are introduced.

TUPS019

Synchrotron Radiation in the LHC Vacuum System

vacuum, dipole, radiation, proton

1563

V. Baglin, G. Bregliozzi, J.M. Jimenez, G. Lanza
CERN, Geneva, Switzerland

CERN is currently operating the Large Hadron Collider (LHC) with 3.5 TeV per beam. At this energy level, when the protons trajectory is bent, the protons emit synchrotron radiation (SR) with a critical energy of 5.5 eV. Under operation, SR induced molecular desorption is routinely observed in the LHC arcs, long straight sections and experiments. This contribution recalls the SR parameters over the LHC ring for the present and nominal beam parameters. Vacuum observations during energy ramp, after accumulation of dose and along the LHC ring are discussed. Expected pressure profiles and long term behaviours of vacuum levels will be also addressed.

TUPS030

Manufacturing and Vacuum Testing of Aluminum Bending Chambers for TPS

vacuum, ion, synchrotron, electron

1596

Y.C. Yang, C.K. Chan, C.-C. Chang, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, T.Y. Lee
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS) is an aluminum alloy vacuum system with 518.4 m circumference divided into 24 sections. A6061T6 aluminum alloy material is used for TPS bending chambers. Each aluminum bending chamber is component of 2 half plates, about 3.5～4.2 m in length and～0.6 m in width, were oil-free CNC machined, ozone cleaned, and TIG welding in clean room. The deformation < 0.1 mm and leakage rate < 2x10-9mbar. L/s for each welded bending chamber has inspected and achieved. A bending chamber is inspecting the thermal outgassing rate test and ultimate pressure. The manufacturing and vacuum test will be described in this paper.

TUPS031

The Installation of One 14 Meter Cell of TPS Vacuum System

vacuum, laser, synchrotron, site

1599

H.P. Hsueh, C.K. Chan, C.H. Chang, C.-C. Chang, C.L. Chen, C.M. Cheng, Y.T. Cheng, G.-Y. Hsiung, S-N. Hsu, I.T. Huang, T.Y. Lee, H.Y. Yan, Y.C. Yang, C.S. huang
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The construction of a new 3 GeV synchrotron facility, Taiwan Photon Source, is ongoing. The vacuum system has been designed with off-site baking for arc section from sector gate valve to sector gate valve. There is no flange used in this arc section besides the two ends connected to sector gate valves. It is a tedious works for install such long vacuum system with aluminum chambers. In this poster, all the detailed installation procedures will be described. All the precaution inspection procedures for all vacuum components to prevent failed components to be installed will also be described. Every three weeks, one cell will be assembled and stored. Experience is being learned and could be used for the vacuum system of future new accelerator like FEL and others.

TUPS045

IFMIF/EVEDA Beam Dump Shielding: Optimized Design of the Front Part

shielding, radiation, neutron, diagnostics

1635

M. García, D. Lopez, A. Mayoral, F. Ogando, J. Sanz, P. Sauvan
UNED, Madrid, Spain
J.M. Arroyo, B. Brañas
CIEMAT, Madrid, Spain

The Beam Dump of the IFMIF/EVEDA accelerator prototype, designed to stop deuteron beam with energy up to 9 MeV and a maximum beam power of 1.12 MW, needs to fulfill radioprotection requirements. The deuteron beam collides with the beam stop and neutron and photon sources are produced. The objective of this paper is to design and justify the front part of the local shielding of the Beam Dump that complies with radiation limits for workers during beam-off phases. This shielding must allow unrestricted maintenance operations inside the vault, where the accelerator is located, after a reasonable cooling time after shutdown. In doing so, two main handicaps have been overcome. On one hand, the reliability of the traditionally used Monte Carlo codes such as MCNPX and PHITS has demonstrated to be very poor for deuteron transport at these low energies. In order to solve this lack, the MCUNED code using TENDL library is proposed to be used for deuteron transport and the prediction of the neutron and photon sources. On the other hand, the lack of space in the area dedicated to the last part of the accelerator demands a specially optimized shielding solution.

TUPS065

Design of the De-ionized Water Treatment for Taiwan Photon Source

controls, ion, status, storage-ring

1686

Z.-D. Tsai, W.S. Chan, C.K. Kuan
NSRRC, Hsinchu, Taiwan

This work presents the water treatment design of Taiwan Photon Source (TPS). The system design is influenced by supplied water quality, water quantity and the selected process scheme. The system is composed of a pretreatment, make-up, and points-of-use filtration systems. The pretreatment system consists of an active carbon tower, a normally cartridge filter and a reversed osmosis (RO) unit. Furthermore, the make-up system consists of an ultraviolent (UV) TOC reduction unit and a ion-exchange resin unit. Following the water treatment process, the proposed system can provide high quality de-ionized water whose resistivity is better than 10 MΩ-cm at 25±0.1 degree C and dissolved oxygen is less than 10 ppb.

TUPS066

Design of Front End Safety Interlock System for Taiwan Photon Source

controls, radiation, status, vacuum

1689

H.Y. Yan, J.-R. Chen, G.-Y. Hsiung, C.K. Kuan, I.C. Sheng, Z.-D. Tsai
NSRRC, Hsinchu, Taiwan

Safety interlock is one of critical subsystems in synchrotron radiation accelerator. A front end (FE) interlock prototype system has been designed, fabricated, and initially tested for Taiwan Photon Source (TPS). TPS FE interlock logic is designed based on that of Taiwan Light Source (TLS), and moderately modified due to the accelerator parameter discrepancy between TPS and TLS. The programmable automation controllers (PAC) have been utilized in FE safety interlock system for their reliability, convenience, processing capability, communication, and stability in user interface. In FE PAC system, touch panels are used as the graphical user interface (GUI) to control and monitor FE components. In addition, with GUI control it is used to beam position monitoring devices as well as confined beam sizes aperture for beam line users. The interlock design such as data acquisition and parameters monitoring for vacuum pressure, flow rate of cooling water, pressure of compressive air, chamber and water temperature, and overall interlock logic are also presented in this paper.

TUPS067

Photon-stimulated Desorption Experiment for a TPS Crotch Absorber

synchrotron, simulation, vacuum, radiation

1692

Y.T. Cheng, G.-Y. Hsiung, C.K. Kuan, A. Sheng, H.Y. Yan
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC) is constructing a large third-generation synchrotron accelerator in Taiwan, the so-called Taiwan Photon Source (TPS). This 3-GeV, 500-mA machine will generate high-density bending-magnet radiation, of which 90 % of the power is absorbed by the crotch absorber in the storage ring. To understand better the beam-cleaning and photon-desorption phenomena of a copper crotch absorber, we have performed a PSD (photon-stimulated desorption) test in Taiwan Light Source (TLS) at Beam line 19 (BL19). Some mathematical modelling, experimental designs and results are also presented here.

TUPS073

Top-Up Safety Simulations for the TPS Storage Ring

storage-ring, quadrupole, electron, sextupole

1707

H.-J. Tsai, C.C. Chiang, P.J. Chou, C.-C. Kuo
NSRRC, Hsinchu, Taiwan

TPS is a 3 GeV third generation light source and operates in the top-up injection scheme. During the top-up injection, the beamline photon shutters are always open. To ensure the radiation safety of beamline experiments, we studied the possible particle leakage to ID and neighboring bending beamlines. The effects of errors on magnets and beam chamber alignments are investigated.

WEXA01

Challenges of 4th Generation Light Sources

FEL, electron, emittance, undulator

3798

C. Pellegrini
SLAC, Menlo Park, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA

In the last few years Free Electron Lasers (FELs) have emerged as exceptionally exciting tools for new science. The results from FLASH (Hamburg) on biological imaging, LCLS (Stanford) which generated the first hard X-ray lasing and the projects proposed or in costruction around the world are rapidly moving the scientific community to the so called “fast science” which demands ultrashort pulses, fs synchronization, high brightness, high coherence X-rays. The basic SASE FEL process used so far converts energy jitter into jitter of the centralwavelength. Processes based on seeding and HGHG seem to offer a number of advantages in terms of bandwidth, coherence, stability and undulator length. This talk will present an overview of the 4th generation light sources, discussing the main challenges afforded in the construction of the operating facilities and considering the trends for the development of future facilities.

Slides WEXA01 [10.640 MB]

WEOBB01

Sub-micrometer Resolution Transverse Electron Beam Size Measurement System based on Optical Transition Radiation

electron, radiation, background, extraction

1964

A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
S.T. Boogert, V. Karataev
JAI, Egham, Surrey, United Kingdom
D. Howell
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Optical Transition Radiation (OTR) appears when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The resolution of the conventional monitors is defined by the Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. For small electron beam dimensions, the PSF form significantly depends on various parameters of the optical system like diffraction of the OTR tails, spherical and chromatic aberrations, etc. In our experiment we managed to create a system which can practically measure the PSF distribution and using a new self-calibration method we are able to calculate transverse electron beam size. Here we represent the development, data analysis and novel calibration technique of a sub-micrometer electron beam profile monitor based on the measurements of the PSF shape, which OTR visibility is sensitive to micrometer electron beam dimensions.

Slides WEOBB01 [2.506 MB]

WEPC052

Spinor Based Calculation of Depolarizing Effects in Circular Lepton Accelerators

synchrotron, resonance, polarization, lepton

2130

O. Boldt, A. Dieckmann, F. Frommberger, W. Hillert
ELSA, Bonn, Germany

Funding: BMBF
The emission of synchrotron radiation strongly influences the beam dynamics in case of ultra relativistic leptons. When storing or accelerating leptons in circular accelerators, the acting magnetic field shows an oscillating behavior in the rest frame of the leptons. Its properties can be determined by a spectral analysis. The stochastic emission of synchrotron light leads to a line broadening within the magnetic field spectrum. This spectrum can be used to simulate depolarizing effects in circular accelerators. Our contribution will present a tracking based calculation of the mentioned spectrum and a spinor-based determination of the resulting population of the spin-up state. These calculations base on the lattice of the electron stretcher accelerator (ELSA, Bonn) and are confirmed by measurements of the polarization.

WEPC134

Unified Accelerator Modeling Using the Bmad Software Library

simulation, lattice, controls, linac

2310

D. Sagan, I.V. Bazarov, J.Y. Chee, J.A. Crittenden, G. Dugan, K. Finkelstein, G.H. Hoffstaetter, C.E. Mayes, S. Milashuk, D. L. Rubin, J.P. Shanks
CLASSE, Ithaca, New York, USA
R. Cope
CSU, Fort Collins, Colorado, USA

Funding: Work supported by the National Science Foundation and by the US Department of Energy under contract numbers PHY-0734867 and DE-FC02-08ER41538.
The Bmad software library has proved to be a useful tool for accelerator simulations owing to its modular, object-oriented design. It is now used in a number of design, simulation and control programs at the Cornell Laboratory for Accelerator-based Sciences and Education. Work is ongoing to expand Bmad in a number of directions. One aim is tohave a complete framework in order to simulate Cornell's Energy Recovery Linac from Gun cathode (including space-charge) to photon generation to photon tracking through to the x-ray experimental end stations. Other work includes synchrotron radiation tracking including reflections from the vacuum chamber walls which is useful for electron cloud investigations, spin tracking, beam break-up instability, intra-beam scattering, etc. This paper will discuss the current state of the Bmad software along with the long-term goals.

WEPC135

Recent Developments in Modeling Time-resolved Shielded-pickup Measurements of Electron Cloud Buildup at CESRTA

vacuum, electron, radiation, pick-up

2313

J.A. Crittenden, Y. Li, X. Liu, M.A. Palmer, J.P. Sikora
CLASSE, Ithaca, New York, USA
R.P. Badman
Syracuse University, Syracuse, USA
S. Calatroni, G. Rumolo
CERN, Geneva, Switzerland
S. Kato
KEK, Ibaraki, Japan

Funding: Work supported by the U.S. National Science Foundation PHY-0734867, PHY-1002467 and the U.S. Department of Energy DE-FC02-08ER41538
The Cornell Electron Storage Ring Test Accelerator program includes investigations into the mitigation of electron cloud buildup using a variety of techniques in custom vacuum chambers. The CESR ring accommodates two such chambers equipped with BPM-style pickup detectors shielded against the direct beam-induced signal. The signals provide time-resolved information on cloud development. Results for diamond-like carbon, amorphous carbon, and TiN coatings have been compared to those for an uncoated aluminum chamber. Here we report on extensions to the ECLOUD modeling code which refine its description of a variety of new types of in situ vacuum chamber comparisons. Our results highlight the sensitivity afforded by these measurements to the modeled photoelectron production and secondary yield parameters. We draw conclusions comparing the photoelectron and secondary yield properties of the various vacuum chamber coatings, including conditioning effects as a function of synchrotron radiation dose. We find substantial conditioning effects in both the quantum efficiency for producing photoelectrons and in the secondary yield.

WEPC141

Application of the SYNRAD3D Photon-Tracking Model to Shielded Pickup Measurements of Electron Cloud Buildup at CesrTA

scattering, electron, simulation, vacuum

2319

L.E. Boon
Purdue University, West Lafayette, Indiana, USA
J.A. Crittenden, T. Ishibashi
CLASSE, Ithaca, New York, USA
K.C. Harkay
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
We present calculations of synchrotron radiation photon reflection in the vacuum chamber at the Cornell Electron Storage Ring Test Accelerator (CesrTA), applying them as input to the electron cloud buildup code ECLOUD to model time-resolved local measurements with shielded pickup detectors. The recently developed SYNRAD3D photon-tracking code employs a reflection model based on data from the Center for X-Ray Optics at LBNL. This study investigates the dependence of electron cloud buildup on the azimuthal position and kinetic energy distribution of photoelectron production on the vacuum chamber wall.

WEPC169

BPM System Interlock for Machine Protection at SOLEIL

undulator, vacuum, power-supply, electron

2379

J.-C. Denard, C. Herbeaux, M. Labat, V. Leroux, A. Loulergue, J.L. Marlats
SOLEIL, Gif-sur-Yvette, France

SOLEIL, a third generation light source, has its Beam Position Monitors (BPM) processed by the LIBERA electronics built by Instrumentation Technologies. This electronics initiated and specified by SOLEIL features a fast hardware interlock output for machine protection. Although interlocks are available in both horizontal and vertical planes, it was initially thought that only the vertical interlocks would be useful. Actually, the high photon beam power densities (up to 1kW/mm2) generated by the in-vacuum undulators could damage vacuum chamber elements in case of corrector power supply failures in horizontal or vertical plane. Crotch absorbers, XBPMs and their upstream absorbers were designed on the basis that they will be protected with interlock thresholds not tighter than ±1mm. This approach was also applied for specifying the apertures of the XBPMs and of their upstream absorbers. More recently tracking simulation has shown that the crotch absorber apertures downstream the new canted undulators needed special attention.

WEPC171

Requirements of a Beam Loss Monitoring System for the CLIC Two Beam Modules

beam-losses, linac, simulation, monitoring

2385

S. Mallows
The University of Liverpool, Liverpool, United Kingdom
E.B. Holzer, A.P. Mechev, J.W. van Hoorne
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

he Compact Linear Collider (CLIC) study investigates the feasibility of a high-energy electron-positron linear collider optimized for a centre of mass energy of 3 TeV. To achieve the high accelerating gradients, the RF power is produced by a novel two-beam acceleration method in which a decelerating drive beam supplies energy to the main accelerating beam. The linacs are arranged in modular structures referred to as the two beam modules which cover 42 km of beamline. Beam losses from either beam can have severe consequences due to the high intensity drive beam and the high energy, small emittance main beam. This paper presents recent developments towards the design of a Cherenkov fiber BLM system and discusses its ability to distinguish losses originating from either beam.

WEPZ011

Fast Cooling of Bunches in Compton Storage Rings

laser, electron, emittance, scattering

2790

E.V. Bulyak
NSC/KIPT, Kharkov, Ukraine
J. Urakawa
KEK, Ibaraki, Japan
F. Zimmermann
CERN, Geneva, Switzerland

We propose an enhancement of laser radiative cooling by utilizing laser pulses of small spatial and temporal dimensions, which interact only with a fraction of an electron bunch circulating in a storage ring. We studied the dynamics of such electron bunch when laser photons scatter off the electrons at a collision point placed in a section with nonzero dispersion. In this case of ‘asymmetric cooling', the stationary energy spread is much smaller than under conditions of regular scattering where the laser spot size is larger than the electron beam; and the synchrotron oscillations are damped faster. Coherent oscillations of large amplitude may be damped within one synchrotron period, so that this method can support the rapid successive injection of many bunches in longitudinal phase space for stacking purposes. Results of extensive simulations are presented for the performance optimization of Compton gamma-ray sources and damping rings.

THPC001

Progress Towards Implementation of Top-up at the Australian Synchrotron

injection, radiation, storage-ring, interlocks

2904

G. LeBlanc, P. Bennetto, M.J. Boland, S. Costantin, R.T. Dowd, Y.E. Tan, D. Zhu, E.D. van Garderen
ASCo, Clayton, Victoria, Australia

The Australian Synchrotron Light Source has enjoyed several years of stable operations with a high degree of availability. It is now time to move towards top-up operations to improve the stability and integrated flux of the photon beam. This paper describes the steps that have been taken and what remains to be done in order to implement top-up injection as the normal operation mode for the first user runs of 2012.

THPC021

Status of Bunch Deformation and Lengthening Studies at the ANKA Storage Ring

radiation, diagnostics, cavity, storage-ring

2951

N. Hiller, A. Hofmann, E. Huttel, V. Judin, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller
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.
At the ANKA storage ring (Karlsruhe, Germany) we use a Hamamatsu synchroscan streak camera to study the current dependent bunch lengthening and deformation effects . Previously the camera was used at an IR port, being available only occasionally. In October 2010, a dedicated “beam line” for the streak camera became operational. It is designed to have minimum dispersion and sufficient flux in the optical range at which the camera is most sensitive. This allows us to measure bunch profiles for a single bunch with a charge of less than 15 pC (40 μA), previously more than 55 pC were required to obtain a comparable signal. Along with the design and built-up, we present further measurements of bunch length and shape for different momentum compaction factors, RF voltages, beam energies and bunch charges to provide a complete bunch length map of the low alpha mode at ANKA.

THPC044

Operation and Performance Upgrade of the Soleil Storage Ring

undulator, vacuum, storage-ring, feedback

3002

A. Nadji, P. Brunelle, M.-E. Couprie, J.-C. Denard, J.-M. Filhol, J.-F. Lamarre, P. Lebasque, A. Loulergue, P. Marchand, L.S. Nadolski, R. Nagaoka, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

SOLEIL delivers photons to 24 beamlines. Up to 22 very diverse insertion devices (IDs) are now installed on the storage ring, and 4 more will come by summer 2011, including a Cryogenic undulator and an electromagnetic/permanent magnet helical undulator, both designed and built at SOLEIL. Work is continuing on beam dynamics and magnetic corrections to reduce the nonlinear effects of all these IDs. A new optics incorporating an additional quadrupole triplet in one long straight section has been successfully tested and will be put in operation by fall 2011. A new coupling correction will also be implemented to maintain the ratio of the vertical to the horizontal emittances at 1% for any IDs configuration. The electron beam orbit stability has been significantly improved reaching a residual noise of 300 nm RMS. Photon LIBERA modules of X-BPM located on the bends, will be integrated soon in the orbit feedback loops. 4905 hours have been delivered in 2010 to the beamlines with an availability of 96.3%. The user operation with the maximum current of 500 mA is foreseen to start by fall 2011, after the completion of the radiation safety tests of the beamlines.

THPC052

Progress Towards Top-up Operation at SSRF

injection, storage-ring, radiation, controls

3008

Z.T. Zhao, H.H. Li, L. Yin, W.Z. Zhang
SINAP, Shanghai, People's Republic of China

The Shanghai Synchrotron Radiation Facility (SSRF) has been in operation for user experiments in decay mode since May 2009. In the meantime various activities to prepare top-up operation at SSRF, including safety analysis and simulation, dedicated instrumentations and interlocks, control software, radiation measurements, injection optimization and top-up operation tests, have been carried out. In this paper, the progress towards top-up operation at SSRF is described together with its achieved performance.

THPC055

Front Ends at ALBA

vacuum, radiation, synchrotron, undulator

3017

J. Marcos, J. Campmany, D. Einfeld, J. Pasquaud
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3GeV 3rd generation synchrotron radiation source built nearby Barcelona currently under commissioning phase. This paper describes the design and installation of the set of 10 Front Ends that have been manufactured and assembled for day-one operation of the facility. This initial set includes 8 Front Ends devoted to transmit the photons generated by both Insertion Device or Bending Magnet sources to experimental Beamlines, and 2 additional Front Ends for electron beam-diagnostics purposes. The design of each individual Front End has been adapted in order to meet the aperture and power load requirements posed by both the characteristics of the photon sources and the needs of the Beamline users. At the same time, an effort has been made in order to keep a suitable degree of standardization among the components of different Front Ends. With this aim a modular design approach has been adopted. The general layout of the Front Ends as well as the design and function of their main components is described. Finally, a brief summary of their performance during the commissioning period is presented.

THPC071

Study of the Possibility of Implementing a Superbend in the Diamond Light Source

dipole, vacuum, radiation, magnet-design

3059

R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.

THPC080

Making Engineering Data Available at the European XFEL

cavity, cryogenics, survey, LLRF

3077

L. Hagge, J. Bürger, J.A. Dammann, S. Eucker, A. Herz, J. Kreutzkamp, S. Panto, S. Sühl, D. Szepielak, N. Welle
DESY, Hamburg, Germany

One of the essential success factors for the European XFEL is up-to-date, complete and consistent engineering data which is readily accessible throughout the project. Such data include for example civil construction drawings of tunnels and buildings; integrated 3D models of accelerator sections; definitions of fabrication processes and test procedures; inspection sheets, test data, standards, contracts and other technical documentation. The data is kept in the DESY Engineering Data Management System (EDMS). The DESY EDMS is the central information platform for the European XFEL and provides procedures for e.g. review & approvals and change management. The poster presents an overview of Engineering Data Management and its benefits at the European XFEL.

THPC081

Status of the Free-Electron Laser FLASH at DESY

FEL, undulator, laser, radiation

3080

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

The free-electron laser facility FLASH at DESY, Germany has been upgraded in 2010. Now, FLASH delivers an electron beam energy up to 1.25 GeV. The longitudinal phase-space is linearized by 3.9 GHz superconducting cavities. The facility delivers to users ultra-short laser like radiation pulses in the range of less than 50 fs to 200 fs in the soft X-ray wavelenth range from 44 down to 4.1 nm. FLASH provides hundreds to thousands pulses per second to users with unprecedented peak brilliance. FLASH will be upgraded with a second undulator beam line and an additional experimental hall. Construction starts Autumn 2011. We summarize the operational status of the ongoing 3rd user period.

THPC086

Status Report on FERMI@Elettra Project

FEL, linac, electron, undulator

3095

F. Parmigiani, M. Svandrlik, D. Zangrando
ELETTRA, Basovizza, Italy

Funding: This work was supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3
FERMI@Elettra, a single-pass FEL user-facility covering the wavelength range from 100 nm (12 eV) to 3 nm (413 eV) located next to the third-generation synchrotron radiation facility Elettra in Trieste, Italy is actually under completion and will start user operation next year. The first seeded lasing was observed in December 2010 and the first experiments have started this year. In this paper an overview of the present status of machine and beamlines systems will be given as well as a status about operation and future upgrade.

THPC089

Study of a Modified Quasi-periodic Undulator

undulator, radiation, electron, insertion

3104

A.L. Wu, Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To suppress high-order harmonic radiation effectively while maintain comparatively higher fundamental radiation intensity, a modified quasi-periodic undulator (QPU) which the magnet blocks have different size is studied in this paper. Then the paper also compares the radiation spectrum of various structural schemes. It is shown that the higher harmonic radiation of this new scheme will be suppressed more effectively than the conventional QPU.

THPC102

Production of Coherent Optical \vCerenkov Radiation in Silica Aerogel

radiation, electron, scattering, emittance

3125

F.H. O'Shea, J.B. Rosenzweig
UCLA, Los Angeles, California, USA

As a demonstration of the apposite properties of silica aerogel as an electron beam diagnostic we intend to use it to produce coherent optical Cˇ erenkov radation (COCR). In this paper we propose an experiment and provide details of the challenges to be overcome in producing COCR.

THPC105

An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

linac, ion, SRF, FEL

3134

C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg
JLAB, Newport News, Virginia, USA

Funding: Support by US DoE contract #DE-AC05-060R23177.
We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ("afterburner"). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

THPC133

Pre-Conceptual Design Requirements For The MaRIE Facility At LANL And The Resulting X-Ray Free Electron Laser Baseline Design

linac, electron, scattering, emittance

3197

R.L. Sheffield, B.E. Carlsten
LANL, Los Alamos, New Mexico, USA

The MaRIE (Matter-Radiation Interactions in Extremes) facility is being proposed to advance materials science by the concurrent utilization of a diverse set of highly penetrating probes. These probes will provide the basis for developing materials that will perform predictably and on demand with currently unattainable lifetimes in extreme environments. The MaRIE facilities, the Multi-Probe Diagnostic Hall (MPDH), the Fission and Fusion Materials Facility (F³), and the Making, Measuring, and Modeling Materials (M4) Facility will each have experimental needs for one or more high-energy x-ray beam probes, but all require a 50-keV coherent source of greater than 10¹0 photons in less than 1 ps. Because of space considerations at the facility, a high-gradient design is being investigated that will use a X-band RF systems to drive a 20-GeV normal-conducting linac. Experimental requirements drive a need for multiple photon bunches over time durations greater than 1 microsecond, as well as interleaving 0.1 nC very-low-emittance bunches with 2-nC electron bunches. This paper will cover an overview of the scientific requirements for the MaRIE XFEL and the baseline XFEL design.

THPC150

Review of Insertion Device Dedicated to HIgh Energy Photons at SOLEIL

vacuum, undulator, brightness, insertion

3236

O. Marcouillé, C. Benabderrahmane, P. Berteaud, F. Briquez, L. Chapuis, M.-E. Couprie, T.K. El Ajjouri, F. Marteau, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France

Producing high energy photons between 10 keV and 70 keV is a challenging topic in a medium energy storage ring. It requires up-to-date measurement techniques and specific Insertion Device (ID) technologies to produce high magnetic fields and short periods. SOLEIL (2.75 GeV) has designed and built eight conventional in-vacuum hybrid undulators operating at high radiation harmonics and also one small gap multipole wiggler to produce high magnetic field. The construction has been progressively improved by the choice of new magnetic materials of better quality and higher magnetization, additional correction techniques and mechanical changes. A 2-m long full scale cryogenic undulator made of PrFeB and vanadium permendur has been built, measured, corrected and is to be tested on the beam. An additional wiggler dedicated for Slicing experiments has been designed. The required magnetic field is high enough to also consider the ID as a good candidate for the production of hard X-ray photons. This paper presents the ID dedicated for the high energy photons and their spectral performances.

THPC161

Possible Superconducting Insertion Devices with Period Length Doubling for Beamlines of Third Generation Light Sources

simulation, insertion, insertion-device, undulator

3269

D. Saez de Jauregui, T. Baumbach, S. Casalbuoni, S. Gerstl, A.W. Grau, M. Hagelstein, T. Holubek
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

The tunability of an insertion device can be increased by period length switching, which in superconducting insertion devices (IDs) can be achieved by reversing the current in separately powered subsets of the superconducting windings. The feasibility of this concept has been experimentally proven. We study here different possibilities to tailor the needs of beamlines of third generation light sources: FEM simulations performed to compute the magnetic field on axis of such devices with different period lengths are reported together with the spectral simulations.

THPC166

Design Consideration of New Insertion Devices of Hefei Light Source

undulator, vacuum, radiation, insertion

3284

Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more insertion devices. In this paper the design considerations of new insertion devices are reported, they include one elliptically polarizing undulator, one quasi-periodic undulator, one in-vacuum undulator and one wiggler.

THPC168

Field Error Correction for a Superconducting Undulator

undulator, radiation, electron, simulation

3290

S. Chunjarean
PAL, Pohang, Kyungbuk, Republic of Korea
C.-S. Hwang, J.C. Jan
NSRRC, Hsinchu, Taiwan
H. Wiedemann
SLAC, Menlo Park, California, USA

To reach higher photon energies in the region of soft or hard x-rays with high photon beam brightness in low energy storage rings, superconducting undulators with very short period length and high magnetic field strength are required. Because undulator radiation comes in a line spectrum, photons up to the 7th harmonic are desired. The photon brightness in such harmonics is strongly dependent on perfect periodicity of the magnetic field. Such imperfections also appear in conventional permanent material undulators, which can be corrected by well developed and efficient shimming. Unfortunately, this method cannot be applied to superconducting undulators. Therefore, we present a new approach to field corrections by modification of the magnetic field saturation in each pole. In this paper it is shown that this approach can reduce not only the magnetic field error but also greatly improves phase errors from period to period. The proposed method works quite local with only small perturbations in neighboring poles. The tenability is preserved for most of the field excitations and is reduced only at extreme parameters.

THPC175

Spectral Analysis of Arbitrary Strength Parameter for Various Insertion Devices

undulator, wiggler, insertion, insertion-device

3311

S.D. Chen, T.M. Uen
NCTU, Hsinchu, Taiwan
C.-S. Hwang
NSRRC, Hsinchu, Taiwan

An insertion device (ID) with medium strength parameter was hard to be defined as a wiggler or an undulator. Usually, this kind of ID was classified according to the user’s definition and to select the spectrum calculation formula of wiggler or undulator. The spectrum calculation formula for wiggler or undulator is quite difference and consequently obtain a big different flux density by using the same strength parameter. So, it is no way that the spectrum calculation of them is consistent. Therefore, a universal formula will be developed for the spectrum analysis for the different kinds of insertion devices that is with large different strength parameter (deflection parameter). Consequently, a modified spectrum calculation formula of ID with medium strength parameter was studied by reviewing the difference of existing spectrum formulas. The familiar formula of calculating undulator spectrum was modified and can be used on ID with arbitrary strength parameter. The algorithm of formula modification was described. Some relative issue, like the effect of phase error and energy spread, and taper undulator were also discussed herein.

THPC176

Progress in Insertion Devices for TPS in Phase I

undulator, insertion, insertion-device, vacuum

3314

C.H. Chang, C.-H. Chang, J.C. Huang, C.-S. Hwang, C.K. Yang
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) with beam energy 3 GeV and beam current 500 mA is a third-generation synchrotron radiation facility of medium energy. In the initial commissioning stage of TPS, the machine will be equipped with ten insertion devices (ID) and serve seven beamlines in phase I. Of these, three long straight sections configured as a double-minimum betay function lattice design with minimized beam influence of emittance are used for the installation of a pair of insertion devices in a straight section, two undulators of APPLE-II type and four in-vacuum undulators (IU), to produce great brilliance and coherent X-rays with great flux. The details of these insertion devices are explained herein.

THPC184

Progress of the Coherent Soft X Ray Straight Section at NSLS-II

undulator, electron, polarization, insertion

3329

C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, D.A. Harder, P. He, Y. Li, C. Meyer, G. Rakowsky, J. Rank, C. Rhein, C.J. Spataro, T. Tanabe
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II (NSLS-II) is the new light source under construction at Brookhaven National Laboratory (BNL). The Coherent Soft X rays beam line (CSX) is one of the six beamlines included in the baseline project. Following the request of CSX scientists for a source providing adjustable polarized radiation from 160 eV to 1.7 keV, two Advanced Planar Polarized Light Emitter II (APPLE-II)-type undulators will be installed in a 6.6 m long straight section. Each device is 2 m long, the period is 49.2 mm and the minimum gap is 11.5 mm. The different operation modes of the beamline and the layout of the straight section are reviewed here.

THPC186

Heat Load for the APS Superconducting Undulator

radiation, simulation, undulator, shielding

3332

L.E. Boon, A.F. Garfinkel
Purdue University, West Lafayette, Indiana, USA
K.C. Harkay
ANL, Argonne, USA

Funding: Work supported by U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Upgrade calls for the development and commissioning of a superconducting undulator (SCU) at the Advanced Photon Source (APS), a 7-GeV electron synchrotron. The first SCU will be installed in June 2012. Until then, simulations such as SYNRAD3D will be used to understand and reduce the heat load on the cryo-system from primary and secondary photons. Current calculations predict that primary photons will distribute 0.5W/m on the chamber walls of the cryostat. SYNRAD3D will be used to calculate the ratio of primary and secondary photons to calculate the heat load due to secondary photons. Previous simulations were of only one sector of the APS accelerator. Simulated here are multiple sectors, to include photons back scattered from downstream photon absorbers.

THPS083

Two-channel Mode of Mo-99 Production at an Electron Accelerator

target, neutron, electron, simulation

3627

V.L. Uvarov, A.N. Dovbnya, V.V. Mytrochenko, V.I. Nikiforov, S.A. Perezhogin, V.A. Shevchenko, B.I. Shramenko, A.Eh. Tenishev, A.V. Torgovkin
NSC/KIPT, Kharkov, Ukraine

High-energy bremsstrahlung is the main source of isotopic target activation at an electron accelerator. The photoneutrons concurrently generated are generally considered as a background radiation. At the same time, the natural materials entering into photonuclear targets sometimes comprise a mixture of stable isotopes, the atomic-number difference of which equals 2. Thus, if the desired isotope has an intermediate mass, then at certain conditions, it can be produced on two target nuclei at once, via (γ,n) and (n,γ) channels. As an example, we investigate the possibility of increasing the yield of 99Mo by means of its simultaneous production from 100Mo(γ,n)99Mo and 98Mo(n,γ)99Mo reactions. The method and the device have been developed to provide measurements of the 99Mo yield from the natural molybdenum target as it is placed inside the neutron moderator and without the latter. Experiments were performed at the NSC KIPT accelerator LU-40m at electron energies ranging from 30 to 60 MeV. It is demonstrated that the use of the moderator gives nearly a 30% increase in the 99Mo yield. The experimental results are in good agreement with the computer simulation data.

THPS084

Modification of the PENELOPE Transport System for HS Simulation of Isotope Production Mode

target, electron, simulation, radiation

3630

V.L. Uvarov, V.I. Nikiforov
NSC/KIPT, Kharkov, Ukraine

A method has been developed for high-speed computing the photonuclear isotope yield along with the absorbed radiation power in exit devices of electron accelerator. The technique involves a step-by-step calculation of isotope microyield along the photon trajectories. The approach has been realized in the computer programs based on the PENELOPE system of -2001, -2006 and -2008 versions. For their benchmarking, use has been made of the experimental data on activity distributions of the 67Cu produced from 68Zn(γ,p)67Cu reaction in thick zinc targets. The results of simulation using the PENELOPE-2006 and -2008 codes are in excellent agreement with all experimental data. At the same time, the PENELOPE-2001 computations give good agreement with the experimental results for target activation by the electron beam, but systematically underestimate (~15%) in case of the target exposed to bremsstrahlung. The proposed technique provides a ~ 10⁴ times higher computation speed as compared with the direct Monte Carlo simulation of photonuclear events and that speed is independent of the reaction cross section.

THPS098

Compact Gamma-ray Source for Non-destructive Detection of Nuclear Material in Cargo

laser, microtron, electron, neutron

3663

R. Hajima
JAEA/ERL, Ibaraki, Japan
I. Daito, T. Hayakawa, Y. Hayashi, M. Kando, H. Kotaki
JAEA, Kyoto, Japan
T. Hori, H. Ohgaki
Kyoto IAE, Kyoto, Japan
N. Kikuzawa
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Shizuma
JAEA APRC, Ibaraki-ken, Japan

Funding: This work is supported by Strategic Funds for Promotion of Science and Technology (Grant No. 066).
A mono-energetic gamma-ray source based on laser Compton scattering is under development for non-destructive detection of nuclear material in cargo. In the detection system, we employ nuclear resonance fluorescence triggered by mono-energetic gamma-rays tuned at the resonance energy of nuclear material such as U-235. As a prototype, a 150-MeV microtron combined with a YAG laser to produce a 400-keV gamma ray is constructed at JAEA, where critical technologies are to be demonstrated for high-flux gamma-ray generation, 3x10⁵ ph/s. We also start to design a microtron at higher energy, 250 MeV, to produce a 2-MeV gamma-ray, which is required for the detection of U-235.

THPS099

Design Study of a Nuclear Material Detection System Based on a Quasi Monochromatic Gamma Ray Generator and a Nuclear Resonance Fluorescence Gamma Ray Detection System

neutron, scattering, laser, background

3666

T. Kii, T. Hori, K. Masuda, H. Ohgaki, M. Omer
Kyoto IAE, Kyoto, Japan
R. Hajima, T. Hayakawa, M. Kando, T. Shizuma
JAEA, Ibaraki-ken, Japan
T. Misawa, C.H. Pyeon
KURRI, Osaka, Japan
H. Toyokawa
AIST, Ibaraki, Japan

Funding: This work was partially supported by Special Coordination Funds for romoting Science and Technology in Japan,
Nuclear Resonance Fluorescence (NRF) measurement is a powerful tool for isotope detection for the homeland security such as a nondestructive measurement of containers at airports or harbors and detection or identification of special nuclear materials. In this paper, we will discuss on basic design of a quasi-monochromatic gamma-ray generator based on the backward Compton scattering of laser light on high-energy electrons and an NRF gamma ray detection system using a high-speed scintillation detector.