IPAC2011 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOPC013	Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC Photo-injector Energy Upgrade	accelerating-gradient, impedance, klystron, FEL	89
	D. Alesini, R. Boni, G. Di Pirro, R. D. Di Raddo, M. Ferrario, A. Gallo, V.L. Lollo, F. Marcellini INFN/LNF, Frascati (Roma), Italy G. Campogiani, A. Mostacci, L. Palumbo, S. Persichelli, V. Spizzo Rome University La Sapienza, Roma, Italy T. Higo, K. Kakihara, S. Matsumoto KEK, Ibaraki, Japan S. Verdú-Andrés TERA, Novara, Italy
	The energy upgrade of the SPARC photo-injector from 170 to 250 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.5m high gradient C-band structures. The structures are traveling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.

MOPC041	Cross-Field Multipactor Discharge in the X-Band Cylindrical Cavity	cavity, multipactoring, electron, vacuum	166
	S.V. Kuzikov, E.V. Ilyakov, I.S. Kulagin, A.A. Vikharev IAP/RAS, Nizhny Novgorod, Russia D. Lee NSRRC, Hsinchu, Taiwan
	The paper represents the experimental study of one-sided cross-field multipactor discharge in the copper cavity with the operating mode TM01 in external DC magnetic field. It was shown that discharge is very sensible to magnitudes of the external magnetic field and rf fields as well. At proper fields the multipactor discharge can be developed for 15 ns and the electron concentration can be comparable with critical one for the given rf frequency. As a result of discharging, the cavity changes its own resonant frequency and can play a role of a switch which can substitute full transmission by full reflection. Switching parameters could be controlled by DC magnetic field as well as by additional rf radiation at different frequency than operating frequency. The high rf absorption of multipactor discharge also can be used in electrically controlled powerful loads and attenuators.

MOPO044	Bunch Length Measurements in Low-Alpha Mode at SPEAR3 with First Time-Resolved Pump/Probe Experiments*	laser, photon, synchrotron, single-bunch	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.

MOPS046	Impedances and Wakes in Round Three-layer Ceramic Waveguide	impedance, acceleration, damping, accumulation	703
	M. Ivanyan, A.V. Tsakanian CANDLE, Yerevan, Armenia
	The round ceramic waveguide with inner and outer thin metal coating is considered. Using the exact methods the longitudinal impedances and potentials are calculated. Identification of the main patterns of changes in their properties by varying the electrodynamic and geometric parameters of the waveguide is performed as well. The possibility of optimizing the parameters of the waveguide for the effective implementation of two-beam acceleration is discussed.

MOPS048	Microbunching Instability Studies at SOLEIL	electron, storage-ring, synchrotron, synchrotron-radiation	709
	C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

TUZA02	sFLASH - Present Status and Commissioning Results	undulator, electron, laser, FEL	923
	V. Miltchev, S. Ackermann, A. Azima, J. Bödewadt, F. Curbis, M. Drescher, E. Hass, Th. Maltezopoulos, M. Mittenzwey, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian Uni HH, Hamburg, Germany H. Delsim-Hashemi, K. Honkavaara, T. Laarmann, H. Schlarb, S. Schreiber, M. Tischer DESY, Hamburg, Germany R. Ischebeck PSI, Villigen, Switzerland S. Khan DELTA, Dortmund, Germany
	The free-electron laser in Hamburg (FLASH) was previously being operated in the self-amplified spontaneous emission (SASE) mode, producing photons in the XUV wavelength range. Due to the start-up from noise the SASE-radiation consists of a number of uncorrelated modes, which results in a reduced coherence. One option to simultaneously improve both the coherence and the synchronisation between the FEL-pulse and an external laser is to operate FLASH as an amplifier of a seed produced using high harmonics generation (HHG). An experimental set-up - sFLASH, has been installed to test this concept for the wavelengths below 40 nm. The sFLASH installation took place during the planed FLASH shutdown in the winter of 2009/2010. The technical commissioning, which began in the spring of 2010, has been followed by seeded-FEL commissioning, FEL-characterisation and pilot experiments. In this contribution the present status and the sFLASH commissioning results will be discussed.
	Slides TUZA02 [4.125 MB]

TUODA03	The Status of the ALICE Accelerator R&D Facility at STFC Daresbury Laboratory	FEL, cavity, electron, diagnostics	934
	F. Jackson, D. Angal-Kalinin, R. Bate, R.K. Buckley, S.R. Buckley, J.A. Clarke, P.A. Corlett, D.J. Dunning, J.-L. Fernández-Hernando, A.R. Goulden, S.F. Hill, D.J. Holder, S.P. Jamison, J.K. Jones, L.B. Jones, A. Kalinin, S. Leonard, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, A.J. Moss, B.D. Muratori, T.T. Ng, J.F. Orrett, S.M. Pattalwar, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, A.D. Smith, R.J. Smith, S.L. Smith, N. Thompson, A.E. Wheelhouse, P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom P. Harrison, G.M. Holder, A.L. Schofield, P. Weightman, R.L. Williams, A. Wolski The University of Liverpool, Liverpool, United Kingdom M.D. Roper STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom M. Surman STFC/DL/SRD, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Science and Technology Facilities Council The ALICE accelerator, the first energy recovery machine in Europe, has recently demonstrated lasing of an infra-red free electron laser (IR-FEL). The current status of the machine and recent developments are described. These include: lasing of the IR-FEL, a programme of powerful coherent terahertz radiation research, electro-optic diagnostic techniques, development of high precision timing and distribution system, implementation of digital low level RF control. ALICE also serves as an injector for the EMMA non-scaling FFAG machine.
	Slides TUODA03 [1.648 MB]

TUZB02	Ultra High Vacuum for High Intensity Proton Accelerators	vacuum, ion, proton, radioactivity	971
	N. Ogiwara JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In high intensity proton accelerators neutrons, as well as gamma rays, are generated. At the J-PARC synchrotron the cumulative energy dose will be of the order of several-mSv/h over 1 month user operation. In order to minimize the radiation exposure during maintenance, it is necessary to construct a vacuum system with reliable components which have a long life in such a high level of radiation. In addition, in all machines it is necessary to keep the operating pressure of the beam in ultra high vacuum (UHV) to suppress pressure instability. At J-PARC RCS the UHV conditions were realized without baking and the beam operation has been successful to date. General considerations for vacuum systems for high intensity linear and circular accelerators will be provided in the talk.
	Slides TUZB02 [3.380 MB]

TUPC001	Simulations of the Interaction Point for TeV-scale e⁺ e− Colliders	photon, electron, simulation, collider	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.

TUPC002	Study of a Large Piwinski’s Angle Configuration for Linear Colliders	luminosity, collider, linear-collider, background	988
	R. Versteegen, O. Napoly CEA/DSM/IRFU, France
	The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC009	The Recent JINR Advances in Technology Development on Linear Accelerators	laser, electron, FEL, cryomodule	1006
	G. Shirkov, N. Balalykin, A. Dudarev, E. Syresin, G.V. Trubnikov, Yu.A. Yulian JINR, Dubna, Moscow Region, Russia E. Khazanov IAP/RAS, Nizhny Novgorod, Russia
	JINR experts take part in a few ILC related projects including photo injector prototype, participation in design and construction of cryomodules, RND on design of a new version of superconducting niobium resonator, laser metrology, etc. Some new results of this activity as well as recent data of ILC siting investigations in the Dubna region are presented.

TUPC012	Fabrication and Validation of the Prototype Supporting System for the CLIC Two-beam Modules	alignment, RF-structure, tandem-accelerator, linac	1015
	N. Gazis, G. Riddone, S. griffet CERN, Geneva, Switzerland A. Samoshkin JINR, Dubna, Moscow Region, Russia
	The Compact LInear Collider (CLIC), currently under study at CERN, aims at the development of a Multi-TeV e⁺ e^- collider and relies upon a novel two-beam acceleration concept. In the two-beam acceleration, the Radio Frequency (RF) power is extracted from a low energy but high-intensity particle beam, and it is transferred to a parallel high energy main beam. The two-beam modules are the smallest repetitive units which compose the two linacs. The RF structures are the most precise components and they are mounted and aligned on specially developed supporting system, which provides stability and quick re-positioning. The supporting girders have stringent stiffness and damping requirements, imposed by beam physics requirements. In addition, several constraints, such as allocated space and weight limitation have to be taken into consideration. This paper describes different girder configurations following various fabrication techniques and materials. Extensive qualification measurements have been performed on the first prototype units, and the main results are also presented.

TUPC028	Background and Energy Deposition Studies for the CLIC Post-Collision Line*	photon, simulation, 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.

TUPC058	Design of a Chirping Cell Attached RF Gun for Ultrashort Electron Generation	gun, electron, cavity, laser	1129
	K. Sakaue, K. Tamai, M. Washio RISE, Tokyo, Japan J. Urakawa KEK, Ibaraki, Japan
	Funding: Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690 We have been developing an S-band photocathode rf electron gun at Waseda university. Our rf-gun cavity was firstly designed by BNL and then, modified by our group. In this paper, we will introduce a newly designed rf-gun cavity with energy chirping cell. To generate an energy chirped electron bunch, we attached extra-cell for 1.6cell rf-gun cavity. Cavity design was done by Superfish and particle tracing by PARMELA. By optimizing the chirping cell, we observed linear chirped electron bunch. The front electron have lower energy than rear. Then transporting about 2m, the bunch can be compressed down to 200fsec electron bunch with the charge of 160pC. This ultrashort bunch will be able to use for generating CSR THz radiation, pumping some material to be studied by pulse radiolysis method, and so on. In this conference, the design of chirping cell attached rf-gun, the results of tracing simulation and plan of manufacturing will be presented.

TUPC066	Charged Particle Beam Profile Detector based on Yb-doped Optical Fibers	proton, ion, linac, laser	1150
	C.S. Søndergaard Aarhus University Hospital, Aarhus, Denmark A. Baurichter, B.R. Nielsen Danfysik A/S, Jyllinge, Denmark G. Boudreault Rigshospitalet Copenhagen, PET and Cyclotron Unit, Copenhagen, Denmark K. Hansen, D.V. Madsen, J. Rasmussen, B.F. Skipper Aarhus School of Engineering, Aarhus, Denmark M. Kristensen Aarhus University, Aarhus, Denmark S.P. Møller ISA, Aarhus, Denmark A. Peters HIT, Heidelberg, Germany
	Funding: The Danish National Advanced Technology Foundation, contract # 002-2005-1 A radiation robust, high dynamic range beam profile detector based on scintillating fibers will be presented. The beam profile detector has been developed for particle therapy type ion beams of multiple hundreds MeV/n in the intensity range from 10⁵ to 10⁹ ions/s as a simple and less expensive replacement for MWPC based detectors. Scintillating fibers are typically based on doped polymers, which are sensitive to radiation damage. Here we report on the advantage of using silica optical fibers doped with rare-earth elements for the purpose of detecting ionizing radiation. Specifically, we find that ytterbium doped fibers generate a strong emission signal in the near-infrared from the Yb³⁺ state when penetrated by ionizing radiation, and that the emission has a high resistance against the accumulated dose in the fiber. We demonstrate the use of such fibers in a beam profile detector for charged particle beams in medical applications (radionuclide production and hadron therapy); more generally they are a promising alternative for prolonged used in ionizing radiation, such as accelerator diagnostics equipment or space applications.

TUPC069	Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL	undulator, optics, electron, photon	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, photon, 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).

TUPC085	Observation of Microwave Radiation using Low-cost Detectors at the ANKA Storage Ring	synchrotron, storage-ring, vacuum, optics	1203
	V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, M.J. Nasse, N.J. Smale KIT, Karlsruhe, Germany F. Caspers CERN, Geneva, Switzerland P. Peier PSI, Villigen, Switzerland
	Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320 Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed because the waveguide cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: The accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths above the waveguide cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity "noise-like" signals.

TUPC086	A Setup for Single Shot Electro Optical Bunch Length Measurements at the ANKA Storage Ring	laser, electron, storage-ring, synchrotron	1206
	N. Hiller, E. Huttel, A.-S. Müller, A. Plech KIT, Karlsruhe, Germany F. Müller, P. Peier, V. Schlott PSI, Villigen, Switzerland
	Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under VH-NG-320. Sponsored by the German Federal Ministry of Education and Research under contract number 05K10VKC Single shot electro optical bunch length measurements, in particular using spectral decoding, are foreseen for the ANKA storage ring. This will allow to resolve fast changes of bunch deformation and structure during the low alpha operation (2-15 ps rms bunch length). This technique uses a chirped laser pulse to probe the field induced birefringence in an electro optical crystal. The laser pulse is then analyzed in a single shot spectrometer. To obtain the birefringence modulation one can either use the near field of the electron bunch (placing the crystal close to the electron bunch in the UHV system of the storage ring), or the far field (coherent synchrotron radiation in the THz range at a THz-/IR-Beamline). The laser needs to supply: sufficient tunability of pulse length, a wide spectrum to allow for a sub-ps resolution. Additionally it must provide a mode-locked operation synchronized to the bunch revolution clock. For this purpose, a mode locked Ytterbium fibre laser system which operates at 10³⁰ nm has been developed at the Paul-Scherrer Institute in Switzerland. We give an overview over the experimental set up in the ANKA storage ring and the status of the project.

TUPC093	CSR Bunch Length Monitor for XFEL/SPring-8 - SACLA	FEL, electron, synchrotron, synchrotron-radiation	1224
	C. Kondo, S. Matsubara, T. Matsumoto JASRI/SPring-8, Hyogo-ken, Japan S.I. Inoue, H. Maesaka, Y. Otake RIKEN Spring-8 Harima, Hyogo, Japan
	SPring-8 Angstrom Compact Free Electron Laser (SACLA) is now under commissioning operation, aimed at the generation of a sub-angstrom free electron laser (FEL). In order to ensure the stable FEL generation, non-distractive bunch length monitors utilizing coherent synchrotron radiation (CSR) are installed. The monitors are located at the downstream of individual bunch compressor (BC1-BC3), and they measure the radiation emitted at the individual last magnets of the chicanes. At the magnets, beams with bunch lengths form 10 fs to 1000 fs generate the CSRs with a spectrum ranging the almost whole infrared region (0.03 - 3 THz). The CSRs are detected by a Schottky diode at the BC1, or pyroelectric detectors and a simple organic lens optical system at BC2 and 3. The bunch length monitor systems are used for bunch length feedback control to obtain the stable lasing by changing the rf parameter of acceleration cavities before the BCs. A preliminary system for the above mentioned system was tested at the SCSS test accelerator, and it showed sufficient performance to measure bunch length up to 300 fs. In this report, we describe the design and the results of the first operation.

TUPC101	Generation of Multimode Quasi-monochromatic Terahertz	electron, linac, gun, cathode	1248
	K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan
	Generation of quasi-monochromatic terahertz (THz) using multimode Coherent Cherenkov Radiation (CCR) on the order of 0.1 THz was investigated. CCR was generated by a hollow dielectric tube covered by a metal and an electron bunch from a photocathode radio-frequency (RF) gun linac. The intensity and frequency of CCR were measured directly by a Michelson interferometer and a bolometer. The frequency spectra measured by the interferometer indicated sharp peaks close to frequencies of 0.09 THz and 0.14 THz, which corresponded to TM03 and TM04 modes, respectively, according to theoretical calculation for a tube with inner and outer radii of 5 mm and 7 mm. The maximum gain of TM03 mode due to the tube length was obtained as 1.5 dB/cm. The other higher modes, e. g. 0.36 THz (TM09) and 0.40 THz (TM010), were also observed from a 150 mm long tube at a bunch charge of 15 pC, which decreased space charge effect and the bunch length. Finally, a new method for bunch diagnostic based on multimode CCR was proposed. The bunch length was estimated to be 0.45 ps at a bunch charge of 5 pC with the intensity ratio of TM03 to TM09 mode.

TUPC121	Development of MCP Based Photon Detectors for the European XFEL	photon, 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.

TUPC122	Use of a Grid Waveguide for Particle Energy Determination	wakefield	1302
	A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: The Education Agency of Russian Federation and the Russian Foundation for Basic Research (09-02-00921). We consider prospect of use of a grid waveguide for determination of energy of charge particles in bunches. The method under consideration is based on measurement of a waveguide mode frequency. Earlier we developed two variants of this method. One of them is based on use of a thin dielectric layer in a waveguide. Other variant is based on use of a waveguide loading with a system of wires coated with a dielectric material. In this paper we offer a new version of the method under consideration. It consists in application of a circular waveguide having a grid wall instead a solid one. The grid cells are assumed to be small. The particle bunch moves along the waveguide axis. The analytical solution of the problem is obtained by means of the averaged boundary conditions. It is shown that there is the single propagating mode. The main advantage of the method consists in an enough strong dependency of particle energy on the mode frequency in some wide frequency range. Note as well that this structure is easy for manufacture and can be embedded in the accelerator channel without big difficulty. A.V.Tyukhtin et al., PAC’07, p.4156; A.V. Tyukhtin, EPAC’08, p.1302; A.V. Tyukhtin, Tech. Phys. Lett. 35, p.263 (2009); A.V. Tyukhtin et al., IPAC’10, p.10⁷¹.

TUPC126	Indirect Measurement of Power Deposition on the IFMIF/EVEDA Beam Dump by means of Radiation Chambers	neutron, diagnostics, light-ion, cathode	1314
	D. Rapisarda, J.M. Arroyo, B. Brañas, A. Ibarra, D. Iglesias, C. Oliver CIEMAT, Madrid, Spain F. Ogando UNED, Madrid, Spain
	Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230 The beam stop of the IFMIF/EVEDA accelerator will be a copper cone receiving a total power of ~1 MW, coming from 9 MeV D⁺ at 125 mA. The mechanical stresses in this beam dump come mainly from the thermal gradients generated in the cone, being therefore related with the power deposition profile. Anomalous situations such as beam misalignments or incorrect focusing can lead to variations in this profile outside the normal operation range. These variations must be detected and corrected for beam dump protection. Due to the interaction between D⁺ and the copper cone important neutron and gamma fluxes are generated around the beam dump (10¹⁰ – 10¹¹ n/cm²/s, 10¹⁰ p/cm²/s) with a spatial profile which is directly linked to the power deposition. In this work, a diagnostic based on a set of radiation chambers is proposed to measure on-line this radiation field, giving indirect information about the power deposition on the beam dump. The sensitivity of the radiation field to the power deposition profile is demonstrated and the diagnostic strategy explained, establishing the main specifications and requirements of the detectors.

TUPC127	Optical Transition Radiation System for ATF2	emittance, target, coupling, simulation	1317
	J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós IFIC, Valencia, Spain J. Cruz, D.J. McCormick, G.R. White, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515 In this paper we present the first measurements performed during the fall 2010 and early 2011 runs. Software development, simulations and hardware improvements to the Multi-Optical Transition Radiation System installed in the beam diagnostic section of the Extraction (EXT) line of ATF2 are described. 2D emittance measurements have been performed and the system is being routinely used for coupling correction. Realistic beam simulations have been made and compared with the measurements. A 4D emittance procedure, yet to be implemented, is also discussed. A demagnifier lens system to improve the beam finding procedure has been designed and will be implemented in a future run. Finally, we discuss further verification work planned for the next run period of ATF.

TUPC135	Beam Loss Monitors Comparison at the CERN Proton Synchrotron	beam-losses, injection, electron, proton	1341
	S.S. Gilardoni, S. Aumon, E. Effinger, J. Gil Flores CERN, Geneva, Switzerland U. Wienands SLAC, Menlo Park, California, USA
	CERN is planning the renovation and upgrade of the beam loss detection system for the Proton Synchrotron (PS). Improved performance in speed–to be able to monitor beam loss on a bunch-by-bunch basis–and in long-term stability–to reduce or avoid the need for periodic calibration–are aimed for. To select the most suitable technology, different detectors were benchmarked in the machine with respect to the same beam loss. The characteristics of the different detectors, the results of the measurement campaign and their suitability as future monitors for the PS are presented.

TUPC147	A Micro-Channel Plate Based Gas Ionization Profile Monitor with Shaping Field Electrodes for the ISIS H⁻ Injector	ion, controls, vacuum, beam-losses	1371
	P.G. Barnes, G.M. Cross, B.S. Drumm, S.A. Fisher, S.J. Payne, A. Pertica, C.C. Wilcox STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Beam profile measurements within the ISIS H⁻ injector line are achieved using destructive devices such as moving wire scanners. To avoid damage to the wires, measurements are made with the injector operating on reduced power. This paper reports the development of a Micro-Channel Plate based profile monitor which allows beam measurements to be made under normal operating conditions. The monitor produces profiles by measuring the +ion current resulting from the interaction of the H⁻ beam with the surrounding residual gas. The 32 channel Micro-Channel Plate is mounted on a rotating arm to enable it to be positioned parallel to the beam for calibration (all channels then measure the same +ion current) and perpendicular to the beam for profile measurements. A 15kV drift field is used together with field shaping electrodes to ensure a flat electric field gradient across the monitor, thereby minimising distortion of the profile due to the electric field. This paper details all aspects of the design and construction of this profile monitor. Beam profiles are compared to previous wire scanner results. Shaping field upgrades are discussed to improve the longitudinal field shape.

TUPC153	Study of the Response of Silicon Photomultipliers in Presence of Strong Cross-talk Noise	photon, beam-losses, 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.

TUPC168	Results from the LHC BRAN Luminosity Monitor at Increased Luminosities	luminosity, emittance, injection, simulation	1428
	R. Miyamoto BNL, Upton, Long Island, New York, USA E. Bravin CERN, Geneva, Switzerland H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger LBNL, Berkeley, California, USA
	Funding: This work supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). The LHC BRAN luminosity monitors are used to monitor and optimize the luminosity at the LHC high luminosity interaction points IP1 and IP5. The Argon gas ionization chambers detect showers produced in the TAN absorbers by neutral particles emerging from pp collisions. The detectors have been operated during the 2010 run by counting the shower rate. As the current 2011 run has the multiplicity of proton-proton collisions per bunch crossing near ten, the detector sees more than one collision per bunch crossing. Therefore, the operation of the detector has been switched to pulse height mode to detect the average shower flux. This paper presents results from recent pulse height mode measurements, including the total and bunch-by-bunch luminosity as well as a determination of the crossing angle at these IPs. Comparisons with luminosity measurements from ATLAS and CMS are also presented.

TUPC169	Single-shot Electro-optic Sampling of Coherent Transition Radiation at the A0 Photoinjector	laser, polarization, diagnostics, electron	1431
	T.J. Maxwell, P. Piot Northern Illinois University, DeKalb, Illinois, USA J. Ruan, R.M. Thurman-Keup Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC under U.S. Dept. of Energy Contract No. DE-AC02-07CH11359, and Northern Illinois Univ. under US Dept. of Defense DURIP program Contract N00014-08-1-10⁶⁴. Future collider applications and present high-gradient laser plasma wakefield accelerators operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation () or the bunch wakefields () with sub-picosecond time resolution. Potential applications in shot-to-shot, non-interceptive diagnostics continue to be pursued for live beam monitoring of collider and pump-probe experiments. Related to our developing work with electro-optic imaging, we present results on single-shot electro-optic sampling of the coherent transition radiation from bunches generated at the A0 photoinjector. J. van Tilborg et al., Phys. Rev. Lett. 96, 014801 (2006). ** M. J. Fitch et al., Phys. Rev. Lett. 87 034801 (2001).

TUPC172	Evaluation and Correction of the Non-linear Distortion of CEBAF Beam Position Monitors	electron, simulation, pick-up	1440
	M. Spata, T.L. Allison, K.E. Cole, J. Musson, J. Yan JLAB, Newport News, Virginia, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The beam position monitors at CEBAF have four antenna style pickups that are used to measure the location of the beam. There is a strong nonlinear response when the beam is far from the electrical center of the device. In order to conduct beam experiments at large orbit excitation we need to correct for this nonlinearity. The correction algorithm is presented and compared to measurements from our stretched wire BPM test stand.

TUPO004	Generation of Attosecond Soft X-ray Pulses in a Longitudinal Space Charge Amplifier	undulator, electron, space-charge, laser	1449
	M. Dohlus, E. Schneidmiller, M.V. Yurkov DESY, Hamburg, Germany
	A longitudinal space charge amplifier (LSCA), operating in soft x-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane) and a short radiator undulator in the end. Broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond x-ray pulses. It is shown that a compact and cheap addition to the soft x-ray free electron laser facility FLASH would allow to generate 60 attosecond (FWHM) long x-ray pulses with the peak power at 100 MW level and a contrast above 98%.

TUPO005	Design Optimization for a Non-Planar Undulator for the JETI-Laser Wakefield Accelerator in Jena	undulator, electron, laser, wakefield	1452
	V. Afonso Rodriguez, T. Baumbach, A. Bernhard, G. Fuchert, A. Keilmann, P. Peiffer, C. Widmann KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai IOQ, Jena, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	In a laser wakefield accelerator (LWFA), excited by a femtosecond laser pulse electrons are accelerated to several 100 MeV within a few centimeters. The energy spread of the electron beam is relatively large and varies from shot to shot. In order to obtain monochromatic photons in an undulator despite the energy spread, the following idea was proposed. Two bending magnets and a drift space in between produces dispersion so that particles with different energies have different transverse positions. The beam enters a non-planar undulator, e.g. cylindrical pole geometry, where the K-value also varies with transverse position. If the two variations in the transverse direction (particle energy and K-value) compensate each other the generated light is more monochromatic than with a conventional planar undulator. In this paper such a modified undulator design optimized for the JETI-LWFA in Jena is presented. An experiment to test this concept is in preparation.

TUPO006	Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators	undulator, electron, dipole, quadrupole	1455
	C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer KIT, Karlsruhe, Germany M. Kaluza, M. Nicolai IOQ, Jena, Germany R. Rossmanith Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
	Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO007	FLUTE, a Linac Based THz Source	linac, gun, synchrotron, synchrotron-radiation	1458
	S. Naknaimueang, M. Schwarz Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany R. Abela, H.-H. Braun, R. Ganter, B. Patterson PSI, Villigen, Switzerland A.H. Albert, T. Baumbach, M. Hagelstein, N. Hiller, E. Huttel, V. Judin, B. Kehrer, R. Kubat, S. Marsching, W. Mexner, A.-S. Müller, M.J. Nasse, A. Plech, R. Rossmanith, M. Schuh KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	We propose a versatile THz source named FLUTE (“Ferninfrarot Linac- Und Test-Experiment”) based on a 30 - 50 MeV S-band linac with bunch compressor, that shall not only provide high field THz pulses applications but shall also serve as a test facility to study important accelerator physics issues. This is also of importance in view of the planned utltra-broadband THz to mid infrared user facility TBONE. Special emphasis is put on studies of bunch compression and beam stability as a function of bunch charge (0.1-5 nC) and of different generation mechanisms of coherent radiation (CSR, CER, CTR). This paper describes the design and layout of the proposed FLUTE machine and presents results of beam dynamic calculations with the tracking programs ASTRA and CSRtrack.

TUPO009	HiSOR-II, Compact Light Source with an Innovative Lattice Design	emittance, lattice, focusing, synchrotron	1464
	A. Miyamoto, S. Sasaki HSRC, Higashi-Hiroshima, Japan
	Funding: This work is partially supported by Cooperative and Supporting Program for Researches and Educations in University sponsored by KEK We proposed a ring that a beam orbit is not closed with one turn and return to starting point after multiple turns around the ring. The idea of this new accumulation ring was inspired based on the torus knot theory. This ring has a long length of the total closed orbit in comparison with a conventional ring which has the orbit of one turn. Therefore this ring can have many straight sections and is advantageous to installation of insertion devices. We are designing a new ring based on the shape of a (3,11) torus knot for our future plan ‘HiSOR-II’. This ring has 11 long straight sections and can place undulators effectively by placing elements such as quadrupole magnets at the place near bending magnet, outside of the orbit crossing section. Furthermore, this ring has about 3 times longer circumference in comparison with the conventional ring, the diameter of the ring is as compact as 15 m, but its circumference is as long as 130 m. On the other hand, this ring must achieve low emittance to operate as the 3rd generation light source ring. Therefore we designed lattice of this ring in reference to MAX-III and achieved low emittance by using bending magnets with combined function.

TUPO010	An Innovative Lattice Design for a Compact Storage Ring	lattice, storage-ring, synchrotron, synchrotron-radiation	1467
	S. Sasaki, A. Miyamoto HSRC, Higashi-Hiroshima, Japan
	Funding: *This work is partially supported by Cooperative and Supporting Program for Researches and Educations in Universities sponsored by KEK. We propose a new concept of lattice design for a compact light source storage ring. In a ring with this new scheme, the electron beam may have extremely longer design orbit than that of a conventional ring. In this ring, a design orbit closes after completing multiple turns. The lattice for realizing this exotic beam orbit can be made by placing conventional accelerator components such as bending magnets, quadrupole magnets, RF cavity and so forth in an appropriate manner onto a projected torus knot in the horizontal orbit plane. Due to an extended closed orbit length, the ring with this type of lattice has larger maximum stored charge if operated in multiple-bunch mode, and has longer bunch-to-bunch interval if operated in a single-bunch mode. Also, essential for a storage ring as the synchrotron light source, a larger number of straight sections may accommodate with many insertion devices. In addition, this new scheme may provide advantages for designing a oscillator-type free electron laser and coherent radiation light source.

TUPO017	Peculiarities of the Excitation of an Optical Resonator by an Electron Beam	electron, undulator, damping, storage-ring	1479
	E.G. Bessonov, M.V. Gorbunkov, A.L. Osipov LPI, Moscow, Russia A.A. Mikhailichenko CLASSE, Ithaca, New York, USA
	The peculiarities of the optical resonator excitation by electrons in a FEL based on the Self-Stimulated Undulator Radiation at main and collateral synchronicity conditions are discussed. E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications, http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPO031	The Shielding Design of BERLinPro	neutron, electron, shielding, linac	1503
	K. Ott, M. Helmecke HZB, Berlin, Germany
	Funding: Funded by the Bundesministerium für Bildung und Forschung and by the Land Berlin. The Helmholtz-Zentrum Berlin started in January 2011 the design and construction of the Berlin Energy Recovery Linac Project BERLinPro as a demonstrator of ERL science and technology. BERLinPro consists of a SRF photo injector, a merger, superconducting booster and linac modules, the ring and a beamdump. The energy is 50 MeV, the maximum current is 100 mA (cw), acceleration to higher energies is an option for the future. The low energy parts of the machine are operated at about 10 MeV. Due to the potential radiation hazard posed by the tremendous beampower the facility will be placed subterraneously. The shielding concept is presented here. We used the Monte Carlo code FLUKA to calculate the details of the shielding, activations, energy doses for radiation damage and energy spectra for realistic scenarios. Due to computing time reasons we used FLUKA calculations in the 50 MeV to 1 GeV range to derive analytical formulas for the vertical shielding. Extrapolation of existing formulas valid in the GeV range (or below 100 MeV) are not applicable because of the rapidly increasing cross section of photo pion production between 100 and 200 MeV.

TUPS002	Photodesorption Measurements at ESRF D31	vacuum, synchrotron, synchrotron-radiation, electron	1518
	H.P. Marques, G. Debut, M. Hahn ESRF, Grenoble, France
	Since 1998 exists at ESRF a dedicated beamline for photodesorption measurement from vacuum chambers - D31. The original goal of this installation was to study the wall pumping effect. When exposed to synchrotron radiation surfaces exhibit strong outgassing of the adsorbed gas layer despite UHV conditions. Long term outgassing leads to the depletion of the adsorbed layer and produces a very clean surface which turns the walls of the vacuum chamber into an active pumping surface. The desorption mechanisms can be described by the long standing models of Knotek-Feibelman (KF) and Menzel-Gomer-Redhead – (MGR) which are themselves encompassed under the name of Desorption Induced by Electronic Transitions (DIET). In these models the surface itself plays a fundamental role in the desorption mechanism. At D31 have been tested chambers of stainless steel, aluminum and copper, with or without coatings (e.g. NEG, copper), designed by ESRF and other institutes like ALBA, CERN, ELETTRA and Soleil. Here we review some of the results obtained and outline the future plans of D31.

TUPS008	The Gas Attenuator Vacuum System of FERMI@Elettra	vacuum, photon, 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.

TUPS016	Vacuum System Design for the MAX IV 3 GeV Ring	vacuum, storage-ring, synchrotron, lattice	1554
	E. Al-dmour, D. Einfeld, J. Pasquaud, M. Quispe CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain J. Ahlbäck, M.J. Grabski, P.F. Tavares MAX-lab, Lund, Sweden
	We describe the conceptual design of the vacuum system of the 3 GeV electron storage ring in the MAX IV facility currently under construction in Lund, Sweden. The standard vacuum chambers are for the most part a cylindrical copper tube with 11 mm inner radius whereas stainless steel will be used at selected locations for beam position monitors, bellows and corrector vacuum chambers. In order to cope with the low vacuum conductance, distributed pumping will be provided through NEG coating of all chambers, including those in dipole magnets making MAX IV the first storage ring to be fully NEG coated. We present the mechanical and thermal design of these chambers and discuss the challenges involved in extracting insertion device radiation as well as coping with the heat load from both IDs and bending magnets in a machine with large bending radius, narrow chambers and tight mechanical tolerance requirements.

TUPS019	Synchrotron Radiation in the LHC Vacuum System	photon, vacuum, dipole, 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.

TUPS025	Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment	vacuum, background, interaction-region, collider	1581
	L. Leduc, G. Corti, R. Veness CERN, Geneva, Switzerland
	The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS032	Overview of EuCARD Accelerator and Material Research at GSI	ion, collimation, heavy-ion, quadrupole	1602
	J. Stadlmann, H. Kollmus, E. Mustafin, N. Pyka, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann GSI, Darmstadt, Germany L.H.J. Bozyk TU Darmstadt, Darmstadt, Germany
	Funding: EuCARD is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 227579 EuCARD is a joined accelerator R&D initiative funded by the EU. Within this program, GSI Darmstadt is performing R&D on materials for accelerators and collimators in WP8(ColMat). GSI covers prototyping and testing of a cryogenic ion catcher for FAIR's main synchrotron SIS100, simulations and studies on activation of accelerator components e.g. halo collimatiors as well as irradiation experiments on materials foreseen to be used in FAIR accelerators and the LHC upgrade program. Carbon-carbon composites, silicon carbide and copper-diamond composite samples have been irradiated with heavy ions at various GSI beamlines and their radiation induced property changes were characterized. Numerical simulations on the possible damage by LHC and SPS beams to different targets have been performed. Simulations and modelling of activation and long term radiation induced damage to accelerator components have started. A prototype ion catcher has been built and first experiments have been performed in 2011. New collaborations with other institutes and industry in the EuCARD framework have been established and findings of the joined R&D effort influence decisions in the FAIR project and LHC upgrade.

TUPS034	Development and Construction of the Beam Dump for J-PARC Hadron Hall	hadron, proton, gun, status	1608
	A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, R. Muto, M. Naruki, Y. Sato, S. Sawada, Y. Shirakabe, Y. Suzuki, H. Takahashi, M. Takasaki, K.H. Tanaka, A. Toyoda, H. Watanabe, Y. Yamanoi KEK, Tsukuba, Japan H. Noumi RCNP, Osaka, Japan
	Funding: This work is supported by Grant-in-Aid (No.22740184) for Young Scientists (B) of the Japan Ministry of Education, Culture, Sports, Science and Technology [MEXT]. A facility of Hadron hall at Japan Proton Accelerator Research Complex (J-PARC) had been constructed in June 2007. Hadron hall is designed to handle intense slow-extraction proton beam from the main accelerator of J-PARC, i.e. 50-GeV-PS. The first transportation of the proton beam to the hall was successfully made in Jan. 2009. A beam dump constructed at the end of the primary proton beam line in Hadron hall is designed to safely absorb 15 μA (=750-kW) proton beam. Its central core of the dump is made of copper with water cooling and is surrounded by iron and concrete for radiation protection. We made thermal and mechanical FEM analysis for investigating heat generation and mechanical stress from energy deposition. We also made cooling experiments for measuring heat transfer coefficient of candidates for new cooling device. As a result, the adopted device has direct cooling paths which are prepared as long holes made by Gun Drill from the outer surface of the copper core. In addition, the beam dump is designed to safely move to 50-m downstream as one body for future expansion of Hadron hall. This paper reports development and construction of the beam dump in Hadron hall.

TUPS035	LHC Collimators with Embedded Beam Position Monitors: A New Advanced Mechanical Design	alignment, collimation, pick-up, simulation	1611
	A. Dallocchio, A. Bertarelli, C.B. Boccard, F. Carra, M. Gasior, L. Gentini, M.A. Timmins CERN, Geneva, Switzerland
	The LHC collimation system, ensuring both functions of beam cleaning and machine protection, is potentially submitted to high-energy beam impacts. Currently the collimators setup is performed by monitoring beam losses generated by the collimator jaws when approaching the particle beam. This procedure is applied to all LHC collimators (almost one hundred), taking several hours, and needs to be repeated if beam settings change significantly. Furthermore, during the beam-based alignment, the LHC tertiary collimators are potentially exposed to abnormal losses entailing possible damage to their tungsten jaws. To improve the efficiency of the machine operation and better control the particle beam a new advanced design embedding Beam Position Monitors (BPM) into the movable collimator jaws has been developed. This paper describes the mechanical design of various types of future collimators with embedded BPMs. Experimental measurements performed on a simplified functional prototype installed in the CERN SPS showed that, thanks to on-board BPMs, the collimator could be precisely, rapidly, and safely aligned and the beam position accurately measured.

TUPS038	Design of a Beam Dump for 3 to 100 MeV for the New H⁻ Beam in the CERN Linac4	linac, vacuum, proton, ion	1620
	C. Maglioni CERN, Geneva, Switzerland
	In this paper the design of a beam dump for the energy range from 3 to 100 MeV is reported. The dump is developed as temporary dump for the commissioning phase of the Linac4 Project, under construction at CERN, and will be installed in different periods to withstand a beam of different intensities and energies, following the chronological assembly of the linac. The dump design and its functionalities, as well as material choice, criticalities and cooling system are described. Finally, the results from the numerical and analytical thermo-mechanical analyses are reported, while the use of the dump also at 160 MeV is investigated.

TUPS039	Reduction of Magnetic Interference on the Position Sensors of the LHC Collimators	shielding, simulation, dipole	1623
	A. Masi, M. Lamberti, R. Losito, M. Martino CERN, Geneva, Switzerland
	The jaws of the LHC collimators have to be positioned with respect to the beam with an accuracy of 20 μm. On some collimators, installed in the LHC transfer lines from SPS, huge reading errors of several tens of micrometers have been observed on the Linear Variable Differential Transformer (LVDT) positioning sensors in synchronization with the variable magnetic field produced by the feed cables of the pulsed resistive dipoles of the transfer line. In this paper we introduce and describe in detail the problem, the model developed using FLUXTM for the simulation of the magnetic flux density generated by the current cables in the complex environment of an LHC transfer line, and the magnetic shielding we designed and implemented. Finally, we compare the results of simulations with experimental measurements taken during on-line pulsed magnets test campaigns.

TUPS040	Driving the LHC Collimators' Stepping Motors over 1 km with High Accuracy avoiding EMI Effects	controls, feedback, impedance, beam-losses	1626
	A. Masi, G. Conte, R. Losito, M. Martino CERN, Geneva, Switzerland
	The LHC collimators are exposed to very high levels of radiation, which means that the power drivers must be installed far from the stepping motors that they drive. Due to the geometry of the underground installations, the distances can be up to 1 km. The long cables that connect the drivers to the motors behave as transmission lines modifying dramatically the impedance seen by the drivers and consequently jeopardizing the control performance of Pulse Width Modulation (PWM) drivers. In this paper we address this problem, provide an analytical model of the driver-cable-motor system and describe the analog solution we have developed to improve the performance of a typical off the shelf driver. Finally we characterize the improvement of the performances with measurements of positioning repeatability and show that electromagnetic emissions from the long cables are drastically reduced, making the use of stepping motors compatible with extremely sensitive instrumentation such as the LHC Beam Loss Monitors (BLM).

TUPS041	Thermo-mechanical Study of a CLIC Bunch Train hitting a Beryllium Energy Spoiler Model	collimation, wakefield, simulation, linac	1629
	J.-L. Fernández-Hernando, D. Angal-Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom J. Resta-López IFIC, Valencia, Spain
	A thermo-mechanical study of the impact a CLIC bunch train has over a beryllium energy spoiler has been made. Beryllium has a high electrical and thermal conductivity which together with a large radiation length compared to other metals makes it an optimal candidate for a long tapered design spoiler that will not generate high wakefields, which might degrade the orbit stability and affect the collider luminosity. This paper shows the progress made from the paper presented last year in IPAC 2010. While in the aforementioned paper the study of the temperature and stress was made for the duration of the bunch train this time the study shows the evolution of the stress in the spoiler body 3 microseconds after the bunch train hit.

TUPS045	IFMIF/EVEDA Beam Dump Shielding: Optimized Design of the Front Part	shielding, photon, 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.

TUPS048	Equipment and Techniques for the Replacement of the ISIS Proton Beam to Target Window	target, shielding, proton, neutron	1638
	S.D. Gallimore, S.J.S. Jago STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS Spallation Neutron Source has been in operation at the Rutherford Appleton Laboratory for over 25 years. Much of the original equipment installed during the construction of the facility is still in operation. The window separating the proton beam transfer line from the neutron target is a key component in the accelerator complex. During the operational life of the Beam Entry Window it has absorbed a considerable amount of energy deposited from the proton beam as it passes from the accelerator vacuum to the target area. Due to the difficulties in accessing and handling the window assembly, a decision was made to replace this component in a planned maintenance period. This paper describes the specialist remote handling equipment and techniques that were developed during the 3 year build up to the removal and replacement of the of the highly active Beam Entry Window.

TUPS053	A Target Magnet System for a Muon Collider and Neutrino Factory	shielding, target, factory, collider	1650
	H.G. Kirk BNL, Upton, Long Island, New York, USA V.B. Graves ORNL, Oak Ridge, Tennessee, USA K.T. McDonald PU, Princeton, New Jersey, USA N. Souchlas, R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: This work is supported in part by the US DOE Contract NO. DE-AC02-98CH10886. The target system envisioned for a Muon Collider or Neutrino Factory includes a 20-T solenoid field surrounding a mercury jet target with the field tapering to 1.5 T 15 m downstream of the target. A principal challenge is to shield the superconducting magnets from the radiation issuing from the 4-MW proton beam impacting the target. We describe a solution which will deliver the desired field while being capable of tolerating the intense radiation environment surrounding the target.

TUPS058	HiRadMat: A New Irradiation Facility for Material Testing at CERN	proton, target, ion, vacuum	1665
	I. Efthymiopoulos, S. Evrard, H. Gaillard, D. Grenier, C. Heßler, M. Meddahi, A. Pardons, C. Theis, P. Trilhe, H. Vincke CERN, Geneva, Switzerland N. Charitonidis EPFL, Lausanne, Switzerland
	HiRadMat (High Irradiation to Materials) is a new facility under construction at CERN designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of 7.2 μs, to a maximum pulse energy of 3.4 MJ. In addition to protons, ion beams with an energy of 173.5 GeV/nucleon and a total pulse energy of 21 kJ can be used. The facility is expected to become operational in autumn 2011. The first tests will include candidate materials and prototype assemblies of LHC collimators foreseen to operate at the ultimate LHC beam powers. Experiments on beam windows and high-power target material options, such as tungsten powder, are also planned. The paper will describe the layout and design parameters for the facility and the way experiments can be operated. Ideas on online and post-irradiation tests and instrumentation will be outlined.

TUPS059	SPS WANF Dismantling: A Large Scale-Decommissioning Project at CERN	shielding, target, feedback, ion	1668
	S. Evrard, Y. Algoet, N. Conan, D. DePaoli, I. Efthymiopoulos, S. Fumey, H. Gaillard, J.L. Grenard, D. Grenier, A. Pardons, E. Paulat, Y.D.R. Seraphin, M. Tavlet, C. Theis, H. Vincke CERN, Geneva, Switzerland
	The operation of the SPS (Super Proton Synchrotron) West Area Neutrino Facility (WANF) was halted in 1998. In 2010 a large scale-decommissioning of this facility was conducted. Besides CERN’s commitment to remove non-operational facilities, the additional motivation was the use of the installation (underground tunnels and available infrastructure) for the new HiRadMat facility, which is designed to study the impact of high-intensity pulsed beams on accelerator components and materials. The removal of 800 tons of radioactive equipment and the waste management according to the ALARA (As Low As Reasonably Achievable) principles were two major challenges. This paper describes the solutions implemented and the lessons learnt confirming that the decommissioning phase of a particle accelerator must be carefully studied as from the design stage.

TUPS063	Power Saving Schemes in the NSRRC	controls, synchrotron, synchrotron-radiation, status	1680
	J.-C. Chang, Y.F. Chiu, J.-M. Lee, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng NSRRC, Hsinchu, Taiwan
	National Synchrotron Radiation Research Center (NSRRC), Taiwan will complete the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in the end of 2012. The power consumption of the TPS is estimated about 2.3 times of that of the existed Taiwan Light Source (TLS). To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include power requirement control, optimization of chillers operation, application of heat pump, air conditioning system improvement, power factor improvement and the lighting system improvement.

TUPS066	Design of Front End Safety Interlock System for Taiwan Photon Source	controls, photon, 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, photon, simulation, vacuum	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.

TUPS071	Performance of the Protection System for Superconducting Circuits during LHC Operation	power-supply, extraction, interlocks, instrumentation	1701
	R. Denz, Z. Charifoulline, K. Dahlerup-Petersen, R. Schmidt, A.P. Siemko, J. Steckert CERN, Geneva, Switzerland
	The protection system for superconducting magnets and bus-bars is an essential part of the LHC machine protection and ensures the integrity of substantial elements of the accelerator. Due to the large amount of hardwired and software interlock channels the dependability of the system is a critical parameter for the successful exploitation of the LHC. The paper will report on observed failure modes, present fault statistics and discuss the overall performance of the protection system during LHC operation in 2010 and 2011. Foreseen measures for further improvements and operational results obtained with already implemented system upgrades will be described.

TUPS072	Performance of the Arc Detectors of LHC High Power RF System	cavity, klystron, plasma, ion	1704
	D. Valuch, O. Brunner, N. Schwerg CERN, Geneva, Switzerland
	During operation, the LHC high power RF equipment, such as klystrons, circulators, waveguides and couplers have to be protected from damage caused by electromagnetic discharges. Once ignited these arcs grow over the full height of the waveguide and travel towards the RF source. The burning plasma can cause serious damage to the metal surfaces or ferrite materials. The LHC arc detector system is based on the optical detection of the discharge through small apertures in the waveguide walls. The light is guided by means of an optical fibre from the view port to a photo diode. Experience shows that some of the currently used optical fibers suffer from x-ray induced opacity. The sensors are also exposed to the radiation produced by secondary showers coming from the high intensity beams which, if not treated properly, can cause frequent spurious trips. In the second half of the paper we presents a number of improvements to the design. Measurements with optical parameters from real arcs and a fiber-less version of the detector with redundant detectors for critical environments.

TUPS084	Development Status of PPS, MPS and TS for IFMIF/EVEDA Prototype Accelerator	controls, status, beam-losses, monitoring	1734
	H. Takahashi, T. Kojima, T. Narita, K. Nishiyama, H. Sakaki, K. Tsutsumi JAEA, Aomori, Japan
	Control System for IFMIF/EVEDA* prototype accelerator consists of six subsystems; Central Control System (CCS), Local Area Network (LAN), Personnel Protection System (PPS), Machine Protection System (MPS), Timing System (TS) and Local Control System (LCS). The IFMIF/EVEDA prototype accelerator provides deuteron beam with the power more than 1 MW, which is as same as that in cases of J-PARC and SNS. Then, the PPS is required to protect technical and engineering staff against unnecessary exposure and the other danger phenomena. The MPS and the TS are strongly required a high performance and precision to avoid radio-activation of the accelerator components. To realize these requirements, the PPS designed that Programmable Logic Controllers (PLCs) are used mainly, and a sequence is programmed for entering and leaving of controlled area and etc. Hardware and logic sequences for the MPS are designed to realize the beam inhibition time within 30 micro-seconds. The TS prototype modules were designed and tested using 10 MHz master clock and 100 Hz reference trigger. This article presents the PPS, MPS and TS design in details. * International Fusion Material Irradiation Facility / Engineering Validation and Engineering Design Activity

TUPS086	Ultra-high Resolution Observation Device for Carbon Stripper Foil	monitoring, vacuum, scattering, proton	1740
	Y. Takeda, Y. Irie, I. Sugai KEK, Ibaraki, Japan
	To observe a growth process of a pinhole on a HBC-foil due to beam irradiation, an up to 10 um of device for ultra-high resolution observation is needed. For the environment where we use the device for observation is so severe as under high radiation and in vacuum, there is no device available for long-time observation. Then, we designed and created a wholly new method based system which enables constant observation by ultra-high resolution even under high radiation environment. We attempted several experiments, compared materials usable under radiation environment, checked up various optical systems which enables high resolution, and finally developed the best method. As a result, we successfully invented an ultra-high resolution observation device available for monitoring an object about 8 meters distant by 8.3um resolution.

TUPS089	HI-13 Tandem Accelerator Radiation Protection System	controls, tandem-accelerator, monitoring, status	1749
	X.F. Wang, Y.M. Hu CIAE, Beijing, People's Republic of China
	In HI-13 Tandem Accelerator laboratory, a new radiation protection system has been built Which composed of 7 protective door control units and 7 emergency alarms , 23 groups of indicators,17 groups of workshop-empty units , L.E and IMAG Faraday cups as well as computer control and display system . Pre-empty process is prerequisite before close the protective doors to ensure nobody be exposed on irradiation environment otherwise the door-open would be disabled. Even thought somebody left, pushing nearby alarm button and emergency door-open button will induce glittery signal and simultaneous door-openning. L.E and IMAG Faraday cups execute immediate beam interruption once accidence occured . The distributed indicators indicate real time status of all the work fields. All above devices and units are interlocked follow some complex but logical protective rules. Computer workstation is built and accordingly, after full information and operation action signals are collected and transferred, the software can complete full-sides status monitoring, provide convenient control and display interfaces as well as pop adequate prompt frames.

TUPS102	Design of an FPGA-based Radiation Tolerant Agent for WorldFIP Fieldbus	controls, target, simulation, status	1780
	G. Penacoba Fernandez, P. Alvarez, E. Gousiou, S.T. Page, J.P. Palluel, J. Serrano, E. Van der Bij CERN, Geneva, Switzerland
	CERN makes extensive use of the WorldFIP field-bus interface in the LHC and other accelerators in the pre-injectors chain. Following the decision of the provider of the components to stop the developments in this field and foreseeing the potential problems in the subsequent support, CERN decided to purchase the design information of these components and in-source the future developments using this technology. The first in-house design concerns a replacement for the MicroFIP chip whose last version was manufactured in an IC feature size found to be more vulnerable to radiation of high energy particles than the previous versions. NanoFIP is a CERN design based on a Flash FPGA implementing a subset of the functionality allowed by the communication standard, fitting the requirements of the different users and including the robustness against radiation as a design constraint. The development presented involved several groups at CERN working together in the framework of the Open Hardware Repository collaboration, and aiming at maximizing the interoperability and reliability of the final product.

TUPZ014	Luminosity Optimization for a Higher-Energy LHC	emittance, luminosity, damping, proton	1831
	C.O. Domínguez, F. Zimmermann CERN, Geneva, Switzerland
	A Higher-Energy Large Hadron Collider (HE-LHC) is an option to further push the energy frontier of particle physics beyond the present LHC. A beam energy of 16.5 TeV would require 20-T dipole magnets in the existing LHC tunnel, which should be compared with 7 TeV and 8.33 T for the nominal LHC. Since the synchrotron radiation power increases with the fourth power of the energy, radiation damping becomes significant for the HE-LHC. It calls for transverse and longitudinal emittance control vis-à-vis beam-beam interaction and Landau damping. The heat load from synchrotron radiation, gas scattering, and electron cloud also increases with respect to the LHC. In this paper we discuss the proposed HE-LHC beam parameters; the time evolution of luminosity, beam-beam tune shifts, and emittances during an HE-LHC store; the expected heat load; and luminosity optimization schemes for both round and flat beams.

WEOAB03	The Production of High Quality Electron Beams in the ALPHA-X Laser Wakefield Accelerator	electron, laser, plasma, emittance	1956
	S.M. Wiggins, M.P. Anania, C. Aniculaesei, E. Brunetti, S. Cipiccia, B. Ersfeld, M.R. Islam, R.C. Issac, D.A. Jaroszynski, G.G. Manahan, R.P. Shanks, G.H. Welsh USTRAT/SUPA, Glasgow, United Kingdom W.A. Gillespie University of Dundee, Nethergate, Dundee, Scotland, United Kingdom A. MacLeod UAD, Dundee, United Kingdom
	Funding: The U.K. EPSRC, the EC's Seventh Framework Programme (LASERLAB-EUROPE / LAPTECH, grant agreement no. 228334) and the Extreme Light Infrastructure (ELI) project. The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme is developing laser-plasma accelerators for the production of ultra-short electron beams as drivers of incoherent and coherent radiation sources from plasma and magnetic undulators. Here we report on the latest laser wakefield accelerator experiments on the University of Strathclyde ALPHA-X accelerator beam line looking at high quality electron beams. ALPHA-X uses a 26 TW Ti:sapphire laser (energy 900 mJ, duration 35 fs) focused into a helium gas jet (nozzle length 2 mm) to generate high quality monoenergetic electron beams with central energy in the range 80-180 MeV. The beam is fully characterized in terms of the charge, bunch length, energy spread and transverse emittance. The energy spectrum (with less than 1% measured energy spread) is obtained using a high resolution magnetic dipole imaging spectrometer while pepper-pot mask measurements show that the normalized transverse emittance is as low as 1.1 pi mm mrad (resolution limited). The conditions needed to obtain this high quality are discussed.
	Slides WEOAB03 [2.904 MB]

WEYB01	Diagnostics for Ultra-low Emittance Beams	laser, polarization, emittance, optics	1959
	J.W. Flanagan KEK, Ibaraki, Japan
	The achievement in recent years of beams with vertical emittance of a few pico-meters in a number of electron storage rings has presented challenges for diagnostics capable of beam size measurements in this regime. A number of different approaches have been developed for various machines (e.g. laser wire; interferometer; Shintake monitor; coded aperture; compound refractive lens). This presentation will review and compare the different methods, and discuss their strengths, weaknesses, ultimate limitations, and the situations where they might be appropriate; and consider possible future directions.
	Slides WEYB01 [2.553 MB]

WEOBB01	Sub-micrometer Resolution Transverse Electron Beam Size Measurement System based on Optical Transition Radiation	electron, photon, 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]

WEOBB03	Electron Bunch Profile Diagnostics in the Few fs Regime using Coherent Smith-Purcell Radiation	electron, diagnostics, vacuum, linac	1970
	N. Delerue LAL, Orsay, France R. Bartolini, G. Doucas, K. Pattle, C. Perry, A. Reichold, R. Tovey JAI, Oxford, United Kingdom
	Funding: John Fell Fund, University of Oxford The rapid developments in the field of laser-driven particle acceleration hold the prospect of intense, highly relativistic electron bunches that are only a few fs long. The determination of the temporal profile of such a bunch presents new challenges. The use of a radiative process such as Smith-Purcell radiation (SPR), whereby the beam is made to radiate a small amount of e/m radiation and the temporal profile is then reconstructed from the measured spectral distribution of the radiation, is particularly promising in this respect. We summarize the advantages of SPR and present the design parameters of a forthcoming experiment at the FACET facility at SLAC with bunch lengths of the order of 60fs rms. We also discuss a new approach to the problem of the recovery of the ‘missing phase’, which is essential for the accurate reconstruction of the bunch profile.
	Slides WEOBB03 [4.627 MB]

WEIB04	Accelertor-based Mega-science Projects in China and Their Impact on Economy	linac, vacuum, ion, electron	1986
	C. Zhang IHEP Beijing, Beijing, People's Republic of China
	Along with the rapid development of national economy in China, a number of accelerator based mega-science projects were constructed, such as the Beijing Electron-Positron Colliders (BEPC) and its major upgrade project (BEPCII), the Hefei Light Source (HLS), the Heavy Ion Research Facility in Lanzhou (HIRFL) and its Cooling Storage Rings (HIEFL-CSR), the Shanghai Synchrotron Radiation Facility (SSRF) and the Dragon-I induction linac. The Beijing Radioactive Ion Facility (BRIF) and the China Spallation Neutron Source (CSNS) are under construction. In this paper, China’s accelerator projects are briefly reviewed and applications of accelerators are reported. The paper emphasizes spinoff of the accelerator technology developed during R&D and construction of the projects. Collaboration between academia and industry on the projects are described. With some examples, the benefits experienced in the laboratory-industry collaboration and approach of its economic impact are illustrated.
	Slides WEIB04 [14.012 MB]

WEPC036	Coherent Synchrotron Radiation Source Based on an Isochronous Accumulator Ring with Femtosecond Electron Bunches	betatron, linac, gun, lattice	2085
	N.Y. Huang NTHU, Hsinchu, Taiwan H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, F. Miyahara, T. Muto, K. Nanbu, Y. Tanaka Tohoku University, Research Center for Electron Photon Science, Sendai, Japan W.K. Lau NSRRC, Hsinchu, Taiwan
	A compact isochronous accumulator ring has been studied as a source of coherent synchrotron radiation (CSR) at a wavelength region from THz to GHz. Since the thermionic rf gun is substantially stable in general, we anticipate a bunch train of very short electron pulses can be provided satisfactorily by means of velocity bunching. Careful numerical simulations show possibility of the bunch length of much less than 100 fs with a bunch charge of 20 pC, which will contain sufficiently large form factor for production of CSR at the wavelengths longer than ~ 0.1 mm. The coherent THz radiation of high average power will be achieved if the short bunches can be circulated in the accumulator ring without bunch lengthening. This paper will describe the optimization of thermionic injector to produce femtosecond bunches in addition to study of the lattice designing of complete isochronous optics for the accumulator ring.

WEPC095	Simulations of the Microbunching Instability at ANKA using a Vlasov-Fokker-Planck Solver	electron, synchrotron, simulation, impedance	2232
	M. Klein, A.-S. Müller KIT, Karlsruhe, Germany K.G. Sonnad CLASSE, Ithaca, New York, USA
	In order to produce coherent synchrotron radiation the ANKA light source is operated frequently in short bunch mode. It is known that during this procedure strong self fields caused by high electron densities can enforce initial density fluctuations and thus lead to microbunching. The build-up of those substructures is accompanied by bursting radiation which provides higher radiation power for the users. Damping and diffusion due to incoherent radiation smoothens the bunch shape again and hence lead to periodic or chaotic bursting cycles. The evolution of the electron bunch density under the influence of self fields can be described by the Vlasov-Fokker-Plank (VFP) equation. We present results from a numerical solution of the VFP-equation for parameters used in standard short bunch mode at ANKA.

WEPC108	CSR Impedance for an Ultrarelativistic Beam moving in a Curved Trajectory	impedance, shielding, vacuum, resonance	2268
	D.M. Zhou, K. Ohmi, K. Oide KEK, Ibaraki, Japan
	A dedicated computer code, CSRZ, has been developed to calculate the coherent synchrotron radiation (CSR) impedance for an ultrarelativistic beam moving in a curved trajectory. Following the pioneering work of T. Agoh and K. Yokoya, the code solves the parabolic equation in the frequency domain in a curvilinear coordinate system. The beam is assumed to move along a vacuum chamber which has a uniform rectangular cross section but with variable bending radius. Using this code, we did investigations in calculating the longitudinal CSR impedance of a single and a series of bending magnets. The calculation results indicate that the shielding effect due to outer chamber wall can be well explained by a simple optical approximation model at high frequencies. The CSR fields reflected by the outer wall may interfere with each other in a long bending magnet and lead to sharp narrow peaks in the CSR impedance. T. Agoh and K. Yokoya, Phys. Rev. ST Accel. Beams, 7(5):054403 (2004).

WEPC135	Recent Developments in Modeling Time-resolved Shielded-pickup Measurements of Electron Cloud Buildup at CESRTA	vacuum, electron, pick-up, photon	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.

WEPC137	Undulator Radiation Simulation by QUINDI	undulator, electron, simulation, polarization	2316
	D. Schiller, E. Hemsing, J.B. Rosenzweig UCLA, Los Angeles, California, USA
	QUINDI, a code developed to simulate coherent emission from bending systems, has been upgraded to include undulators as a beamline element. This approach allows us to better model the radiation produced by a relativistic electron bunch propagating through such a device.

WEPC163	A New Embedded Radiation Monitor System for Dosimetry at the European XFEL	undulator, neutron, controls, linac	2364
	F. Schmidt-Föhre, D. Nölle, R. Susen, K. Wittenburg DESY, Hamburg, Germany L. Fröhlich ELETTRA, Basovizza, Italy
	The upcoming European XFEL will be built at a length of approx. 3.4 km between the campus of the Deutsches Elektronen-Synchrotron DESY at Hamburg and Schenefeld at Schleswig-Holstein for commissioning in 2015. The XFEL utilizes various electronic systems for machine control, diagnostics and safety. To achieve a cheap and compact accelerator construction, the beam pipe and its nearby electronic supply systems are located inside the same tunnel, charged by an evident amount of radiation in certain sections of the XFEL. To insure the lifecycle and function of electronics and magnetic structures like undulators in these XFEL radiation fields, all electronic systems located inside the tunnel will be sufficiently shielded according to pre-estimated radiation levels. In addition, these electronics and the undulator parts will be monitored for the impact of Gamma- and Neutron-radiation by a new versatile and compact radiation monitor system. It measures the accumulated dose in the electronic cabinets along the XFEL to ensure an exchange of radiated parts before significant radiation damage occurs. First prototype measurements at different radiation sources will be presented.

WEPC164	First Operation of a Fiber Beam Loss Monitor at the SACLA FEL	undulator, beam-losses, vacuum, electron	2367
	X.-M. Maréchal, T. Itoga JASRI/SPring-8, Sayo-gun, Japan Y. Asano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.

WEPC165	Monte Carlo Simulation of the Total Dose Distribution around the 12 MeV UPC Race-track Microtron and Radiation Shielding Calculations	shielding, simulation, target, beam-losses	2370
	C. de la Fuente, M.A. Duch, Yu.A. Kubyshin UPC, Barcelona, Spain V.I. Shvedunov MSU, Moscow, Russia
	The Technical University of Catalonia is building a miniature 12 MeV electron race-track microtron for medical applications. In the paper we study the leakage radiation caused by beam losses inside the accelerator head, as well as the bremstrahlung radiation produced by the primary beam in the commissioning setting. Results of Monte Carlo simulations using the PENELOPE code are presented and two shielding schemes, global and local, are studied. The obtained shielding parameters are compared with estimates based on international recommendations of the radiation safety standards.

WEPC166	Licensing and Safety Issues of the ESS Accelerator	shielding, target, beam-losses, neutron	2373
	P.E.T. Jacobsson, M. Brandin, D. Ene, T. Hansson ESS, Lund, Sweden
	The licensing process for the European Spallation Source (ESS) has started up. The process includes both an application to the Environmental Court in Sweden as well as the application towards the Swedish Radiation Protection Authority (SSM). The applications will be based on an Environmental Impact Assessment EIA) and a Safety Analysis Report (SAR). One important step has been to define which regulations that apply for ESS. ESS has also set up General Safety Objectives (GSO). Based on the GSO and the legal requirements, the process design of the whole ESS facility is ongoing. This paper will focus upon the radiation safety issues related to the accelerator. This includes items as radiation shielding, personal protection system and operation emissions. Analyses and calculations, based on a preliminary design and layout of the ESS accelerator, will be presented. Discussion is made on issues like shielding material, shielding design and analysis models.

WEPC176	Beam Loss Monitoring and Machine Protection System Design and Application for the ALICE Test Accelerator at Daresbury Laboratory	beam-losses, monitoring, dipole, simulation	2400
	S.R. Buckley, J.-L. Fernández-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	ALICE is a demonstrator accelerator system which has been designed and built at Daresbury Laboratory. The heart of this facility is an ERL accelerator and a powerful multi-terrawatt laser. It serves as an advanced test facility for novel accelerator and photon science applications. Beam loss monitoring and machine protection systems are vital areas for the successful operation of ALICE. These systems are required, both for efficient machine set up and for hardware protection during operation. This paper gives an overview of the system design, commissioning details and a summary of the systems’ effectiveness as a diagnostic tool.

WEPO033	Update on the Modification and Testing of the MICE Superconducting Spectrometer Solenoids*	solenoid, magnet-design, emittance, focusing	2469
	S.P. Virostek, M.A. Green, N. Li, T.O. Niinikoski, H. Pan, S. Prestemon, M.S. Zisman LBNL, Berkeley, California, USA A. Langner CERN, Geneva, Switzerland
	Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231. The Muon Ionization Cooling Experiment (MICE) is an international effort sited at Rutherford Appleton Laboratory, which will demonstrate ionization cooling in a segment of a realistic cooling channel using a muon beam. A pair of identical, 3-m long spectrometer solenoids will provide a 4-tesla uniform field region at each end of the cooling channel. The emittance of the beam as it enters and exits the cooling channel will be measured within the 400 mm diameter magnet bores. The magnets incorporate a three-coil spectrometer magnet section and a two-coil section that matches the solenoid uniform field into the MICE cooling channel. The cold mass, radiation shield and leads are kept cold by means of a series of two-stage cryocoolers and one single-stage cryocooler. Previous testing of the magnets had revealed several operational issues related to heat leak and quench protection. A quench analysis using Vector Fields software and detailed heat leak calculations have been carried out in order to assess and improve the magnet design. Details of the analyses and resulting magnet design modifications along with an update of the magnet assembly and testing progress will be presented here.

WEPO035	Thermal Performance of the S1-Global Cryomodule for ILC	cavity, cryomodule, linac, vacuum	2472
	N. Ohuchi, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya KEK, Ibaraki, Japan T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross Fermilab, Batavia, USA A. Bosotti, C. Pagani, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, N.J. Walker, H. Weise DESY, Hamburg, Germany
	The S1-Global program is the international research collaboration among INFN, FNAL, DESY, SLAC and KEK as one of the GDE R&D for construction of ILC. The S1-Global cryomodule consists of two half-size cryomodules of 6 meter. One was designed by IFNF, and it contained two FNAL cavities and two DESY cavities. The associated components, like input couplers and RF cables, were same as the TTF-III cryomodule. The other was designed by KEK, and the thermal design was based on the TTF-III cryomodule. This cryomodule contains four KEK cavities with the associated components which were designed by KEK. For characterizing the thermal performances of two cryomodules, the static heat load and the temperature profiles of the cold components were measured. The temperature profiles of the components were compared between two cryomodules and the static heat load was evaluated with the design values of the cryomodules. The dynamic losses of the DESY, FNAL and two KEK cavities at their maximum operative gradients were measured and, with the measured losses, Q values were calculated. In this paper, we will make the summary of the thermal measurements of the S1-Global cryomodule.

WEPS029	Innovative Superconducting Non Scaling Fixed Field Alternating Gradient Isocentric Gantry for Carbon Cancer Therapy*	focusing, ion, dipole, proton	2544
	D. Trbojevic BNL, Upton, Long Island, New York, USA V.S. Morozov JLAB, Newport News, Virginia, USA
	Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy. Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.

WEPS047	Beamloss Study at J-PARC Linac by using Geant4 Simulation	beam-losses, simulation, scattering, linac	2595
	T. Maruta JAEA/J-PARC, Tokai-mura, Japan
	Beamloss is one of the key issue for intense hadron beam accelerators. Most of case, origin of beamloss is scattering process between beam particle and residual gas inside vacuum duct. In the case of J-PARC Linac, H⁻ ions emitted from an Ion source are accelerated up to 181 MeV, then the beam is transported to RCS. The H⁻ ion is the system comprised from a proton and two electrons. If the H⁻ ion is scattered with residual gas, these one or two electrons are escaped, then H⁻ becomes H0 or H⁺(proton). H0 or H⁺ is uncontrollable and finally it goes to beam duct. This process is based on physics process, and Geant4 is matched to this kind of simulation study. I programmed SDTL (50 MeV) to L3BT (181 MeV) section at J-PARC Linac by using Geant4 code. I also wrote H⁻ and H0 library which makes it possible for Geant4 to simulate them. I will show the simulation results.

WEPZ005	Field Calculations to obtain Attosecond/Femtosecond Electron Bunches	cathode, laser, electron, injection	2772
	V.A. Papadichev LPI, Moscow, Russia
	Obtaining short electron bunches of attosecond and femtosecond duration in a combined quasi-static and laser electric field [* - ***] requires careful field formation in the cathode region. First, the maximum of laser electric field normal to the cathode plate, depending on the incidence angle, was found employing Fresnel formulae using complex dielectric permittivity of metals. Second, laser field enhancement on cathode spikes was calculated for the case of an ellipsoid in a qusi-static approximation (laser wavelength larger than spike dimensions). Field enhancement is approximately proportional to the square of the ratio of major to minor axes of ellipsoid. Thus, enhancement factors as large as 100 - 1000 are obtainable, allowing to reduce laser power by 10 thousand to 1 million times. V.A.Papadichev, Patent RU 2 269 877 C1, 10.02.06, Bull. 4. V.A.Papadichev, Proc. EPAC08, p.2812. * V.A.Papadichev, Proc. EPAC08, p.2815. **** V.A.Papadichev, Proc. IPAC'10, p. 4372

WEPZ006	Forming Attosecond Electron Pulses in Space-charge Dominated Regime	electron, laser, acceleration, bunching	2775
	V.A. Papadichev LPI, Moscow, Russia
	Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [, , *]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions. V.A.Papadichev, Proceedings of EPAC08, p.2815. V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372. * V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.

WEPZ012	Influence of Transition Radiation on Formation of a Bunch Wakefield in a Circular Waveguide	vacuum, wakefield, plasma, acceleration	2793
	T.Yu. Alekhina, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: The Education Agency of Russian Federation. Investigation of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration (WFA) technique and other problems in the accelerator physics. One of subjects of investigation in this area consists in analysis of transition radiation generated by the bunch flying into (out of) the dielectric structure. This radiation can be both destructive (for WFA) and useful (for diagnostics of bunch or material). We investigate the total field of small bunch crossing a boundary between two dielectrics in the waveguide. It includes a “forced” field and a “free” one. The “forced” field is the field of the charge in the unbounded waveguide (it can contain the wakefield). The “free” field is connected with influence of the boundary (it includes transition radiation). Two cases are analyzed in detail: the bunch flies from vacuum into dielectric and from dielectric into vacuum. The behavior of the field depending on distance and time is explored analytically and numerically. Some interesting physical effects are noted. As well, we make a comparison with the case of intersection between vacuum and cold plasma.

THOAB01	Accelerator-driven Subcritical Molten-salt-fueled Reactors	neutron, target, linac, proton	2868
	R.P. Johnson Muons, Inc, Batavia, USA C. Bowman ADNA, Los Alamos, New Mexico, USA
	Reactors built using solid fissile materials sealed in fuel rods have an inherent safety problem in that volatile radioactive materials in the rods are accumulated and can be released in dangerous amounts. Accelerator parameters for subcritical reactors that have been considered in recent studies have primarily been based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium-burning accelerator-driven energy amplifier proposed by Rubbia et al. An attractive alternative reactor design that used molten salts was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels. These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work as well or better than conventional reactors, having better efficiency due to their higher operating temperature, having the inherent safety of subcritical operation, and having constant purging of volatile radioactive elements to eliminate their accumulation and potential accidental release in dangerous amounts.
	Slides THOAB01 [5.723 MB]

THOAB02	Metal Nano-particle Synthesis by using Proton Beam	proton, electron, controls, cyclotron	2871
	M.H. Jung, K. R. Kim, S.J. Ra KAERI, Daejon, Republic of Korea
	Funding: This work was conducted as a part of the Proton Engineering Frontier Project supported by the Ministry of Education Science & Technology of Korea Government. Many scientists have studied metal nano-particles for newly known optical, electronic and chemical properties. The unique properties of nano-particles have a tendency to relate the particle size and shape. Electron beam have been used for the nano-particle synthesizing and many results were published. Study of nano-particles synthesize by using proton beam is still in the early stages however study for gold, silver, platinum and cobalt nano-particle was in progress. 100 MeV proton linear accelerator, which is by Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, is scheduled to be completed by 2012. Study of nano-particle synthesize by using proton beam will become active due to the completion of 100 MeV proton accelerator and it can be mass-produced because of the large current beam. Finally, industrial applications could become possible. The mechanism of metal nano-particles synthesizing by proton beam irradiation was not completely known. In this study, we investigated the changes of size and shape for metal nano-particle depending on the condition of proton beam irradiation, and concentration of additives by TEM and UV/Vis spectrophotometer.
	Slides THOAB02 [9.791 MB]

THOBB03	Research and Development of Novel Advanced Materials for Next-generation Collimators	impedance, target, collimation, beam-losses	2888
	A. Bertarelli, G. Arnau-Izquierdo, F. Carra, A. Dallocchio, M. Gil Costa, N. Mariani CERN, Geneva, Switzerland
	Funding: This work has partly been carried out through the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program. The study of innovative collimators is essential to handle the high energy particle beams required to explore unknown territory in basic research. This calls for the development of novel advanced materials, as no existing metal-based or carbon-based material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by collimator extreme working conditions. A new family of materials, with promising features, has been identified: metal-diamond composites. These materials are to combine the outstanding thermal and physical properties of diamond with the electrical and mechanical properties of metals. The best candidates are Copper-Diamond (Cu-CD) and Molybdenum-Diamond (Mo-CD). In particular, Mo-CD may provide interesting properties as to mechanical strength, melting temperature, thermal shock resistance and, thanks to its balanced material density, energy absorption. The research program carried out on these materials at CERN and collaborating partners is presented, mainly focusing on the theoretical investigation, material characterization, and manufacturing processes.
	Slides THOBB03 [3.948 MB]

THPC001	Progress Towards Implementation of Top-up at the Australian Synchrotron	injection, storage-ring, photon, 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.

THPC013	THz Studies at a Dedicated Beamline at the MLS	electron, synchrotron, synchrotron-radiation, storage-ring	2933
	R. Müller, A. Hoehl, A. Serdyukov, G. Ulm PTB, Berlin, Germany J. Feikes, M. Ries, G. Wüstefeld HZB, Berlin, Germany
	The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin. The MLS is designed and prepared for a special machine optics mode (low-alpha operation mode) based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the THz region. At the MLS two bending magnet beamlines dedicated to the use of IR and THz synchrotron radiation are in operation: the MLS-IR beamline optimized for the NIR to FIR, and a dedicated THz beamline optimized for the FIR/THz spectral range. Low-alpha operation optic modes for different ring energies, 250 MeV, 350 MeV, 450 MeV and 630 MeV are available. We compare the THz spectra taken in the different low-alpha modes and discuss the results. J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011). ** R. Müller et al., J. Infrared Milli Terahz Waves, in press (2011), DOI: 10.10⁰⁷/s10762-011-9785-6.

THPC014	Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring	cavity, optics, focusing, electron	2936
	G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries HZB, Berlin, Germany
	A scheme is discussed, where short and long bunches can be stored simultaneously in the BESSY II storage ring. With recent developments in sc-rf cavity technology it becomes possible, to install high gradient cavities in electron storage rings. With an appropriate choice of these cavities stable fixed points with different rf-voltage gradients are available, leading to different zero current bunch lengths. For BESSY II, we discuss the simultaneously storage of bunches with rms-lengths of 2 ps and 15 ps at high beam intensities. Additionally, in a low alpha optics sub-ps and ps-bunches are possible and a double bucket optics can be set up to store the two types of beams simultaneously on different orbits. Ultra-short and long bunches can be supplied to the users, separated by slightly different orbits.

THPC015	A Dedicated THz Beamline at DELTA	laser, electron, simulation, undulator	2939
	M. Höner, M. Bakr, H. Huck, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Work supported by DFG, BMBF, and by the Federal State NRW As a consequence of the new radiation source for ultrashort VUV pulses at DELTA, which is based on the interaction of electrons with fs laser pulses, coherent THz radiation is emitted. Simulations of the laser-electron interaction, particle dynamics and radiation spectrum, as well as the optical and mechanical design of a dedicated THz beamline are presented. First experimental results including laser-electron overlap diagnostics and characterization of the THz radiation are discussed.

THPC016	Ultrashort VUV and THz Pulse Generation at the DELTA Storage Ring	laser, electron, undulator, klystron	2942
	A. Schick, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, P. Ungelenk, M. Zeinalzadeh DELTA, Dortmund, Germany
	Funding: Supported by DFG, BMBF, and the Federal State NRW The optical klystron (two undulators, separated by a dispersive section) at DELTA, formerly operated as storage-ring FEL, is seeded with ultrashort pulses from a Ti:Sapphire laser. The thus induced energy modulation of an electron bunch in the first undulator is converted to a density modulation within the dispersive chicane. In the second undulator, the micro-bunched electrons emit ultrashort pulses coherently at harmonics of the fundamental laser wavelength. Additionally, coherent ultrashort THz pulses are generated several meters downstream of the optical klystron by the laser-induced gap in the electron bunch. First results are presented.

THPC021	Status of Bunch Deformation and Lengthening Studies at the ANKA Storage Ring	diagnostics, cavity, storage-ring, photon	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.

THPC023	Third Generation Light Source Project in Iran	dipole, booster, emittance, lattice	2954
	J. Rahighi, E. Salimi, R. safian IPM, Tehran, Iran M. Jafarzadeh, Kh.S. Sarhadi ILSF, Tehran, Iran
	The Institute for Research in Fundamental Sciences (IPM) is in charge of the establishing the Iranian Light Synchrotron Source Facility (ILSF). This facility will be a 3rd generation 3 GeV storage ring with a circumference of roughly 300 m. The injector will consist of a 150 MeV Linac and a full energy booster synchrotron. The storage ring has a four-fold symmetry with 4 long (7.88m), 16 medium (4.0 m) and 12 short (2.8 m) straight sections. Within the medium straight section there are mini beta values in order to get an optimized flux density for the users. The emittance is in the range of 3 nmrad. The booster synchrotron has a circumference of roughly 192 m with an emittance of roughly 31 nmrad. It is a separated function machine in order to have the maximum flexibility. For both machine it is foreseen to use a 500 MHZ RF-system with normal conducting cavities. The machine will be build in an international collaboration, in which the main components have to be supplied from international market. The conceptual design report should be finished in 2012, the commissioning of the machine is expected to be in 2020.

THPC027	Top-up Operational Experience at Elettra	storage-ring, injection, booster, controls	2966
	E. Karantzoulis, A. Carniel, S. Krecic ELETTRA, Basovizza, Italy
	Since May 2010 Elettra, the third generation Italian light source, operates regularly for users at both 2 and 2.4 GeV in top-up. In this paper the experience during more than a year of operation in top-up at both user energies is discussed and the machine up time statistics presented and compared with the before top up period.

THPC040	Expected Performance Characteristic of Accelerator-based THz Source at Tohoku University	electron, undulator, focusing, gun	2990
	H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka Tohoku University, School of Science, Sendai, Japan N.Y. Huang NTHU, Hsinchu, Taiwan
	Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003. Sources of coherent synchrotron radiation at THz wavelength region have been constructed at Tohoku University. Bunch train of extremely shorter electron pulse less than 100 fs will be provided by an injector linac employing thermionic rf gun, where the bunch compression will be performed by means of velocity bunching in an accelerator structure. Radiation source under development are a Halbach type planar undulator and an accumulator isochronous ring. The undulator employs large gap and long period length configuration, so that the resonant frequency of 1 THz is achieved when a lower beam energy of ~ 20 MeV. Since spectrum of coherent synchrotron radiation (CSR) is strongly depending on longitudinal bunch form factor, we have calculated CSR spectra for various conditions of the beam to evaluate the performance of the THz source. Numerical simulation with multi-particle system has been carried out to understand the radiation power and angular distribution as well. The beam transport in the undulator is crucial for quality of the radiation because the beam energy is very much low relative to strong focusing power. Characteristics of THz CSR from the undulator will be discussed.

THPC041	Injector System of Test Accelerator as Coherent Terahertz Source	gun, cavity, electron, cathode	2993
	S. Kashiwagi, H. Hama, F. Hinode, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka Tohoku University, School of Science, Sendai, Japan N.Y. Huang NTHU, Hsinchu, Taiwan F. Miyahara KEK, Ibaraki, Japan
	Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003. A test accelerator as a coherent terahertz source (t-ACTS) project has been under development at Tohoku University, in which a generation of intense coherent terahertz (THz) radiation from sub-picosecond electron bunch will be demonstrated. We will supply a wide-band coherent radiation from bending magnets in an isochronous ring and a narrow-band coherent THz radiation using an undulator in a linac. Stable generation of very short electron bunch is one of the key issues in the t-ACTS project. The injector system is consists of a thermionic RF gun with two independent cavity cells, an alpha magnet and an accelerating structure. A velocity bunching scheme is employed to produce the very short electron bunch. Components of the t-ACTS injector except the accelerating structure have already been installed and we have started a high power RF processing of the gun cavities. The characteristics of electron bunch extracted from the RF gun are measured by varying phase and amplitude of input RF fields for the gun cavities. The status of t-ACTS project will be presented in the conference.

THPC052	Progress Towards Top-up Operation at SSRF	injection, storage-ring, controls, photon	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.

THPC053	Shanghai Soft X-Ray Free Electron Laser Test Facility	laser, linac, FEL, electron	3011
	Z.T. Zhao SINAP, Shanghai, People's Republic of China
	As a critical development step towards constructing a hard X-ray FEL in China, a soft X-ray FEL test facility (SXFEL) was proposed and will be constructed at the SSRF campus by a joint team of Institute of Tsinghua University and Shanghai Institute of Applied Physics. This test facility, based on an 840MeV electron linear accelerator, aims at generating 9nm FEL radiation with two-stage cascaded HGHG scheme. The project proposal was approved in February 2011 by central government, and the constrction is expected to start in early 2012. This paper describes the preliminary design of this soft X-ray test facility and the R&D progress of the key FEL technologies in the SDUV-FEL test bench.

THPC054	Project Status of the Polish Synchrotron Radiation Facility Solaris	storage-ring, linac, synchrotron, cavity	3014
	C.J. Bocchetta, P.P. Goryl, K. Królas, M. Mlynarczyk, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak Solaris, Krakow, Poland J. Ahlbäck, Å. Andersson, M. Eriksson, M.A.G. Johansson, D. Kumbaro, S.C. Leemann, L. Malmgren, J.H. Modéer, P.F. Tavares, S. Thorin MAX-lab, Lund, Sweden E. Al-dmour, D. Einfeld CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Funding: European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09 The Polish synchrotron radiation facility Solaris is being built at the Jagiellonian University in Krakow. The project is based on an identical copy of the 1.5 GeV storage ring being concurrently built for the MAX IV project in Lund, Sweden. A general description of the facility is given together with a status of activities. Unique features associated with Solaris are outlined, such as infra-structure, the injector and operational characteristics.

THPC055	Front Ends at ALBA	vacuum, photon, 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.

THPC068	CSR and THz Emission Measurements at the Diamond Light Source	electron, bunching, dipole, vacuum	3050
	R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas Diamond, Oxfordshire, United Kingdom I.P.S. Martin JAI, Oxford, United Kingdom
	After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

THPC071	Study of the Possibility of Implementing a Superbend in the Diamond Light Source	dipole, vacuum, magnet-design, photon	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.

THPC076	FEL Performance with Focusing Lattice Magnets Alignment Errors	FEL, quadrupole, alignment, simulation	3071
	V.G. Khachatryan, M. Ivanyan CANDLE, Yerevan, Armenia
	At the European XFEL the alignemnet errors of the undulator section quadrupole magnets will be corrected by applying beam based quadrupole alignment methods. Numerical simulations of the SASE process have been conducted to evaluate the FEL power reduction due to residual quadrupole alignment errors. FEL simulations with focusing lattice errors allow choosing an optimal error correction method in terms of FEL performance.

THPC081	Status of the Free-Electron Laser FLASH at DESY	FEL, undulator, photon, laser	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.

THPC082	Properties of the Radiation from the European X-ray Free Electron Laser	electron, FEL, undulator, emittance	3083
	E. Schneidmiller, M.V. Yurkov DESY, Hamburg, Germany
	Recent success of the Linac Coherent Light Source (LCLS) demonstrated feasibility for reliable production, compression, and acceleration of electron beams with emittances significantly smaller than original baseline parameters. The same scenario can be applied to the European XFEL as well. Experimental results from the Photo Injector Test Facility in Zeuthen (PITZ) demonstrated the possibility to generate electron beams with small charge and emittance. Computer modeling of the beam formation system also indicate on the possibility to preserve electron beam quality during acceleration and compression. Recently these trends have been analyzed, and baseline parameters of the European XFEL have been revised. Parameter space has been significantly extended in terms of the bunch charge. As a result, different modes of FEL operation become possible with essentially different properties of the radiation. In this paper we present an overview of radiation properties of SASE FEL radiators driven by electron beam with new baseline parameters.

THPC083	Analysis of Parameter Space of a Kilowatt-scale Free Electron Laser for Extreme Ultraviolet Lithography Driven by L-band Superconducting Linear Accelerator Operating in a Burst Mode	electron, FEL, undulator, laser	3086
	E. Schneidmiller, V. Vogel, H. Weise, M.V. Yurkov DESY, Hamburg, Germany
	The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in a burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 10 mA. In this paper we analyze the parameter space for optimum operation of the FEL at the wavelength of 13.5 nm and 6.7 nm. Our analysis shows that the FLASH technology holds great potential for increasing the average power of the linear accelerator and an increase of the conversion efficiency of the electron kinetic energy to the light. Thus, it will be possible to construct a FLASH like free electron laser with an average power up to 3 kW. Such a source meets the requirements of the light source for the next generation lithography.

THPC084	Optical Afterburner for a SASE FEL: First Results from FLASH	electron, FEL, undulator, resonance	3089
	M. Foerst CFEL, Hamburg, Germany M. Gensch HZDR, Dresden, Germany R. Riedel, E. Schneidmiller, N. Stojanovic, F. Tavella, M.V. Yurkov DESY, Hamburg, Germany
	Radiation Pulse from a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) consists out of spikes (wavepackets). Energy loss in the electron beam (averaged over radiation wavelength) also exhibits spiky behaviour on a typical scale of coherence length, and follows the radiation pulse envelope. These modulations of the electron beam energy are converted into large density (current) modulations on the same temporal scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful optical radiation is then generated with the help of a dedicated radiator (afterburner). Envelope of the optical afterburner pulse is closely resembles the envelope of the x-ray pulse. We have recently demonstrated this principle at the Free Electron Laser in Hamburg (FLASH). We use THz undulator that is installed after the main X-ray as both dispersive element and radiator simultaneously. We characterize properties of the optical pulse using standard laser diagnostics techniques (i.e. FROG). Main result comes from the pulse duration measurement that we use to derive envelope of the x-ray radiation pulse duration which is in sub-100 fs range.

THPC089	Study of a Modified Quasi-periodic Undulator	undulator, photon, 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.

THPC100	Full Temporal Reconstruction using an Advanced Longitudinal Diagnostic at the SPARC FEL	FEL, diagnostics, undulator, laser	3119
	G. Marcus, J.B. Rosenzweig UCLA, Los Angeles, California, USA M. Artioli, F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy A. Bacci, M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, A. Mostacci, A.R. Rossi INFN/LNF, Frascati (Roma), Italy A. Cianchi INFN-Roma II, Roma, Italy V. Petrillo Istituto Nazionale di Fisica Nucleare, Milano, Italy J.V. Rau ISM-CNR, Rome, Italy
	The Production of ultra-short (sub 100 fs) single-spike radiation possessing full longitudinal coherence from a free-electron laser (FEL) has been the subject of intense study. A Frequency-Resolved Optical Gating (FROG) diagnostic has been developed and tested at UCLA, which has the capability of providing a longitudinal reconstruction of these ultra-fast pulses. This paper reports the results of the application of the diagnostic at the SPARC FEL facility.

THPC102	Production of Coherent Optical \vCerenkov Radiation in Silica Aerogel	electron, scattering, photon, 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.

THPC108	Commissioning of the 50 MeV Preinjector Linac for the BESSY II Facility	linac, booster, emittance, injection	3140
	T. Atkinson, M. Helmecke, D. Schüler, E. Weihreter HZB, Berlin, Germany V. Dürr BESSY GmbH, Berlin, Germany D. Jousse, J.-L. Pastre, A.S. Setty THALES, Colombes, France
	A turn key 50MeV linac manufactured by Thales has been installed in the BESSY II facility. This linac will replace the existing Microtron injector in the near future to provide more flexible bunch population patterns for the femto-slicing operation mode and a higher single bunch intensity for top-up injection. This paper describes the essential problems which have been faced during commissioning and presents the main results obtained in the site acceptance tests including the measurement of beam emittance and energy spread.

THPC118	Present Status of Quantum Radiation Sources on the Basis of the S-band Compact Electron Linac	laser, electron, cavity, linac	3164
	R. Kuroda, E. Miura, H. Toyokawa, K. Yamada, E. Yamaguchi AIST, Tsukuba, Ibaraki, Japan M. Kumaki RISE, Tokyo, Japan
	We have developed quantum radiation sources such as a laser Compton scattering (LCS) X-ray and a coherent THz radiation sources on the basis of the S-band compact electron linac at AIST in Japan. The S-band linac consists of the laser-driven photocathode rf gun and two 1.5 m-long acceleration tubes and can accelerate the electron beam up to about 42 MeV. The LCS X-ray source can generate a quasi-monochromatic hard X-ray with variable energy of 12 - 40 keV for medical and biological applications. Now, the multi-collision LCS system has been developed with the regenerative amplifier type laser storage cavity and the multi-bunch electron beam to increase the X-ray yield. On the other hand, the high-power coherent THz radiation source has been also developed and its peak power is estimated to be more than 1 kW in frequency range between 0.1 - 2 THz. The high-power THz radiation was applied to the scanning transmission imaging. Now, the high power THz time domain spectroscopy (TDS) has been developed for the material science. In this conference, we will report the present status of the S-band compact electron linac, our quantum radiation sources and applications.

THPC146	The Radiated EMI Isolation for TPS Kicker Magnet*	shielding, kicker, electromagnetic-fields, controls	3227
	C.S. Chen, C.K. Chan, C.L. Chen, Y.L. Chu, K.H. Hsu, C.Y. Kuo, Y.-H. Liu, C.-S. Yang NSRRC, Hsinchu, Taiwan
	Electromagnetic interference is a critical problem for electronic equipment, especially for those sophisticated measuring sensors using in TLS. Therefore, lots of efforts have been made to isolate the EM noise from the kicker magnets. In this article, different thicknesses of aluminum chambers are applied to block the radiated EM noise. Furthermore, the different widths of slits simulate the necessary openings on kicker assembly. According to the results of small-scale experiment, some parameters are obtained to design the enclosure of kicker magnet. Compared the results with the data from the original scale kicker, these parameters provide a believable guideline in the beginning of design status.

THPC164	Phase Shifters for the FERMI@Elettra Undulators	undulator, electron, FEL, polarization	3278
	B. Diviacco, R. Bracco, D. Millo, M.M. Musardo ELETTRA, Basovizza, Italy
	The variable gap undulator system in operation at the FERMI@Elettra Free Electron Laser facility requires adjustable phase matching devices between consecutive radiator segments in order to maintain optimal lasing conditions while changing the radiation properties. A permanent magnet phase shifter has been designed to achieve the required electron beam delay in a compact structure that could be installed in close proximity to the undulators. In this paper we present the design of the phasing units and the results of the magnetic measurements performed on the five devices installed so far. We also describe the method used to properly set their field strength for any given electron energy, radiation wavelength and polarization.

THPC165	Estimations for Demagnetization of ID Permanent Magnets due to Installation of OTR	electron, permanent-magnet, simulation, undulator	3281
	Y. Asano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Bizen JASRI/SPring-8, Hyogo, Japan
	Demagnetization due to high energy electron irradiation is one of the crucial issues for stable operation of X-ray free electron laser (XFEL) and Synchrotron radiation (SR) facilities. Especially, during the commissioning, electron beam is scattered and then hits permanent magnets of insertion devices due to installation of some instrumentations such as OTR (Optical Transition Radiation) for beam diagnosis so that the estimation of demagnetization is very important to perform the commissioning smoothly. Fortunately, we found the index of demagnetization of Nd2Fe14B permanent magnets due to high energy electron irradiation. Star density produced by high energy photo-neutron reproduces experimental results of demagnetization. At SPring-8, in-vacuum type undulators have been employed for XFEL so that we estimate the demagnetization of the undulators for various cases such as electron energy in ranging from 2 GeV to 8 GeV and the permanent magnet gap from 2 mm to 40 mm. And we also estimate the allowable time to be able to insert the OTR.

THPC166	Design Consideration of New Insertion Devices of Hefei Light Source	undulator, vacuum, photon, 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.

THPC167	The Design of Dual Canted In-vacuum Undulators at SSRF	undulator, vacuum, ion, synchrotron	3287
	X. Hu, L. Yin, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	Funding: National foundation for scientific infrastructure, Development and Reform Commission of China. Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC168	Field Error Correction for a Superconducting Undulator	undulator, photon, electron, simulation	3290

Paper

Title

Other Keywords

Page

Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC Photo-injector Energy Upgrade

accelerating-gradient, impedance, klystron, FEL

89

D. Alesini, R. Boni, G. Di Pirro, R. D. Di Raddo, M. Ferrario, A. Gallo, V.L. Lollo, F. Marcellini
INFN/LNF, Frascati (Roma), Italy
G. Campogiani, A. Mostacci, L. Palumbo, S. Persichelli, V. Spizzo
Rome University La Sapienza, Roma, Italy
T. Higo, K. Kakihara, S. Matsumoto
KEK, Ibaraki, Japan
S. Verdú-Andrés
TERA, Novara, Italy

The energy upgrade of the SPARC photo-injector from 170 to 250 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.5m high gradient C-band structures. The structures are traveling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.

MOPC041

Cross-Field Multipactor Discharge in the X-Band Cylindrical Cavity

cavity, multipactoring, electron, vacuum

166

S.V. Kuzikov, E.V. Ilyakov, I.S. Kulagin, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia
D. Lee
NSRRC, Hsinchu, Taiwan

The paper represents the experimental study of one-sided cross-field multipactor discharge in the copper cavity with the operating mode TM01 in external DC magnetic field. It was shown that discharge is very sensible to magnitudes of the external magnetic field and rf fields as well. At proper fields the multipactor discharge can be developed for 15 ns and the electron concentration can be comparable with critical one for the given rf frequency. As a result of discharging, the cavity changes its own resonant frequency and can play a role of a switch which can substitute full transmission by full reflection. Switching parameters could be controlled by DC magnetic field as well as by additional rf radiation at different frequency than operating frequency. The high rf absorption of multipactor discharge also can be used in electrically controlled powerful loads and attenuators.

MOPO044

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

laser, photon, synchrotron, single-bunch

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.

MOPS046

Impedances and Wakes in Round Three-layer Ceramic Waveguide

impedance, acceleration, damping, accumulation

703

M. Ivanyan, A.V. Tsakanian
CANDLE, Yerevan, Armenia

The round ceramic waveguide with inner and outer thin metal coating is considered. Using the exact methods the longitudinal impedances and potentials are calculated. Identification of the main patterns of changes in their properties by varying the electrodynamic and geometric parameters of the waveguide is performed as well. The possibility of optimizing the parameters of the waveguide for the effective implementation of two-beam acceleration is discussed.

MOPS048

Microbunching Instability Studies at SOLEIL

electron, storage-ring, synchrotron, synchrotron-radiation

709

C. Evain, J. Barros, J.B. Brubach, L. Cassinari, M.-E. Couprie, G. Creff, M. Labat, A. Loulergue, L. Manceron, R. Nagaoka, P. Roy, M.-A. Tordeux
SOLEIL, Gif-sur-Yvette, France

Microbunching instability arises in storage rings when the number of electrons in a bunch exceeds a threshold value. Its signature, i.e. a strong and irregular emission of Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) domain, is studied at SOLEIL on the AILES infrared beamline, with the storage ring tuned in a low-alpha configuration (used to get shorter electron bunch). The comparison of this observed THz CSR with numerical simulations of the longitudinal electron bunch dynamics, permits to put in evidence that during the instability a modulation appears and drifts in the longitudinal profile of the electron bunch. The understanding of this instability is important as it limits some operation of the storage rings. Indeed the induced fluctuations prevent the use of THz on the far IR beamline at high current per bunch. And in normal alpha operation this instability may spoil the electron/laser interaction effects used to get femtosecond and/or coherent pulse in storage rings (with slicing, Coherent Harmonic Generation or EEHG schemes on storage ring).

TUZA02

sFLASH - Present Status and Commissioning Results

undulator, electron, laser, FEL

923

V. Miltchev, S. Ackermann, A. Azima, J. Bödewadt, F. Curbis, M. Drescher, E. Hass, Th. Maltezopoulos, M. Mittenzwey, J. Rönsch-Schulenburg, J. Roßbach, R. Tarkeshian
Uni HH, Hamburg, Germany
H. Delsim-Hashemi, K. Honkavaara, T. Laarmann, H. Schlarb, S. Schreiber, M. Tischer
DESY, Hamburg, Germany
R. Ischebeck
PSI, Villigen, Switzerland
S. Khan
DELTA, Dortmund, Germany

The free-electron laser in Hamburg (FLASH) was previously being operated in the self-amplified spontaneous emission (SASE) mode, producing photons in the XUV wavelength range. Due to the start-up from noise the SASE-radiation consists of a number of uncorrelated modes, which results in a reduced coherence. One option to simultaneously improve both the coherence and the synchronisation between the FEL-pulse and an external laser is to operate FLASH as an amplifier of a seed produced using high harmonics generation (HHG). An experimental set-up - sFLASH, has been installed to test this concept for the wavelengths below 40 nm. The sFLASH installation took place during the planed FLASH shutdown in the winter of 2009/2010. The technical commissioning, which began in the spring of 2010, has been followed by seeded-FEL commissioning, FEL-characterisation and pilot experiments. In this contribution the present status and the sFLASH commissioning results will be discussed.

Slides TUZA02 [4.125 MB]

TUODA03

The Status of the ALICE Accelerator R&D Facility at STFC Daresbury Laboratory

FEL, cavity, electron, diagnostics

934

F. Jackson, D. Angal-Kalinin, R. Bate, R.K. Buckley, S.R. Buckley, J.A. Clarke, P.A. Corlett, D.J. Dunning, J.-L. Fernández-Hernando, A.R. Goulden, S.F. Hill, D.J. Holder, S.P. Jamison, J.K. Jones, L.B. Jones, A. Kalinin, S. Leonard, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, A.J. Moss, B.D. Muratori, T.T. Ng, J.F. Orrett, S.M. Pattalwar, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, A.D. Smith, R.J. Smith, S.L. Smith, N. Thompson, A.E. Wheelhouse, P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
P. Harrison, G.M. Holder, A.L. Schofield, P. Weightman, R.L. Williams, A. Wolski
The University of Liverpool, Liverpool, United Kingdom
M.D. Roper
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
M. Surman
STFC/DL/SRD, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Science and Technology Facilities Council
The ALICE accelerator, the first energy recovery machine in Europe, has recently demonstrated lasing of an infra-red free electron laser (IR-FEL). The current status of the machine and recent developments are described. These include: lasing of the IR-FEL, a programme of powerful coherent terahertz radiation research, electro-optic diagnostic techniques, development of high precision timing and distribution system, implementation of digital low level RF control. ALICE also serves as an injector for the EMMA non-scaling FFAG machine.

Slides TUODA03 [1.648 MB]

TUZB02

Ultra High Vacuum for High Intensity Proton Accelerators

vacuum, ion, proton, radioactivity

971

N. Ogiwara
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In high intensity proton accelerators neutrons, as well as gamma rays, are generated. At the J-PARC synchrotron the cumulative energy dose will be of the order of several-mSv/h over 1 month user operation. In order to minimize the radiation exposure during maintenance, it is necessary to construct a vacuum system with reliable components which have a long life in such a high level of radiation. In addition, in all machines it is necessary to keep the operating pressure of the beam in ultra high vacuum (UHV) to suppress pressure instability. At J-PARC RCS the UHV conditions were realized without baking and the beam operation has been successful to date. General considerations for vacuum systems for high intensity linear and circular accelerators will be provided in the talk.

Slides TUZB02 [3.380 MB]

TUPC001

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

photon, electron, simulation, collider

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.

TUPC002

Study of a Large Piwinski’s Angle Configuration for Linear Colliders

luminosity, collider, linear-collider, background

988

R. Versteegen, O. Napoly
CEA/DSM/IRFU, France

The application of a Large Piwinski’s Angle configuration to the interaction region of a linear collider is studied. The calculation of the equivalent disruption parameter and beamstrahlung parameter in the presence of a crossing angle are necessary to estimate the beam-beam effects in such a configuration. The reduction of the beam-beam interaction effects, based on these parameters, while keeping same luminosity is presented for both ILC and CLIC parameters.

TUPC009

The Recent JINR Advances in Technology Development on Linear Accelerators

laser, electron, FEL, cryomodule

1006

G. Shirkov, N. Balalykin, A. Dudarev, E. Syresin, G.V. Trubnikov, Yu.A. Yulian
JINR, Dubna, Moscow Region, Russia
E. Khazanov
IAP/RAS, Nizhny Novgorod, Russia

JINR experts take part in a few ILC related projects including photo injector prototype, participation in design and construction of cryomodules, RND on design of a new version of superconducting niobium resonator, laser metrology, etc. Some new results of this activity as well as recent data of ILC siting investigations in the Dubna region are presented.

TUPC012

Fabrication and Validation of the Prototype Supporting System for the CLIC Two-beam Modules

alignment, RF-structure, tandem-accelerator, linac

1015

N. Gazis, G. Riddone, S. griffet
CERN, Geneva, Switzerland
A. Samoshkin
JINR, Dubna, Moscow Region, Russia

The Compact LInear Collider (CLIC), currently under study at CERN, aims at the development of a Multi-TeV e⁺ e^- collider and relies upon a novel two-beam acceleration concept. In the two-beam acceleration, the Radio Frequency (RF) power is extracted from a low energy but high-intensity particle beam, and it is transferred to a parallel high energy main beam. The two-beam modules are the smallest repetitive units which compose the two linacs. The RF structures are the most precise components and they are mounted and aligned on specially developed supporting system, which provides stability and quick re-positioning. The supporting girders have stringent stiffness and damping requirements, imposed by beam physics requirements. In addition, several constraints, such as allocated space and weight limitation have to be taken into consideration. This paper describes different girder configurations following various fabrication techniques and materials. Extensive qualification measurements have been performed on the first prototype units, and the main results are also presented.

TUPC028

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

photon, simulation, 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.

TUPC058

Design of a Chirping Cell Attached RF Gun for Ultrashort Electron Generation

gun, electron, cavity, laser

1129

K. Sakaue, K. Tamai, M. Washio
RISE, Tokyo, Japan
J. Urakawa
KEK, Ibaraki, Japan

Funding: Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690
We have been developing an S-band photocathode rf electron gun at Waseda university. Our rf-gun cavity was firstly designed by BNL and then, modified by our group. In this paper, we will introduce a newly designed rf-gun cavity with energy chirping cell. To generate an energy chirped electron bunch, we attached extra-cell for 1.6cell rf-gun cavity. Cavity design was done by Superfish and particle tracing by PARMELA. By optimizing the chirping cell, we observed linear chirped electron bunch. The front electron have lower energy than rear. Then transporting about 2m, the bunch can be compressed down to 200fsec electron bunch with the charge of 160pC. This ultrashort bunch will be able to use for generating CSR THz radiation, pumping some material to be studied by pulse radiolysis method, and so on. In this conference, the design of chirping cell attached rf-gun, the results of tracing simulation and plan of manufacturing will be presented.

TUPC066

Charged Particle Beam Profile Detector based on Yb-doped Optical Fibers

proton, ion, linac, laser

1150

C.S. Søndergaard
Aarhus University Hospital, Aarhus, Denmark
A. Baurichter, B.R. Nielsen
Danfysik A/S, Jyllinge, Denmark
G. Boudreault
Rigshospitalet Copenhagen, PET and Cyclotron Unit, Copenhagen, Denmark
K. Hansen, D.V. Madsen, J. Rasmussen, B.F. Skipper
Aarhus School of Engineering, Aarhus, Denmark
M. Kristensen
Aarhus University, Aarhus, Denmark
S.P. Møller
ISA, Aarhus, Denmark
A. Peters
HIT, Heidelberg, Germany

Funding: The Danish National Advanced Technology Foundation, contract # 002-2005-1
A radiation robust, high dynamic range beam profile detector based on scintillating fibers will be presented. The beam profile detector has been developed for particle therapy type ion beams of multiple hundreds MeV/n in the intensity range from 10⁵ to 10⁹ ions/s as a simple and less expensive replacement for MWPC based detectors. Scintillating fibers are typically based on doped polymers, which are sensitive to radiation damage. Here we report on the advantage of using silica optical fibers doped with rare-earth elements for the purpose of detecting ionizing radiation. Specifically, we find that ytterbium doped fibers generate a strong emission signal in the near-infrared from the Yb³⁺ state when penetrated by ionizing radiation, and that the emission has a high resistance against the accumulated dose in the fiber. We demonstrate the use of such fibers in a beam profile detector for charged particle beams in medical applications (radionuclide production and hadron therapy); more generally they are a promising alternative for prolonged used in ionizing radiation, such as accelerator diagnostics equipment or space applications.

TUPC069

Bunch Length Measurements from the Incoherent Synchrotron Radiation Fluctuation at SOLEIL

undulator, optics, electron, photon

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, photon, 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).

TUPC085

Observation of Microwave Radiation using Low-cost Detectors at the ANKA Storage Ring

synchrotron, storage-ring, vacuum, optics

1203

V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, M.J. Nasse, N.J. Smale
KIT, Karlsruhe, Germany
F. Caspers
CERN, Geneva, Switzerland
P. Peier
PSI, Villigen, Switzerland

Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320
Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed because the waveguide cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: The accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths above the waveguide cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity "noise-like" signals.

TUPC086

A Setup for Single Shot Electro Optical Bunch Length Measurements at the ANKA Storage Ring

laser, electron, storage-ring, synchrotron

1206

N. Hiller, E. Huttel, A.-S. Müller, A. Plech
KIT, Karlsruhe, Germany
F. Müller, P. Peier, V. Schlott
PSI, Villigen, Switzerland

Funding: Supported by the Initiative and Networking Fund of the Helmholtz Association under VH-NG-320. Sponsored by the German Federal Ministry of Education and Research under contract number 05K10VKC
Single shot electro optical bunch length measurements, in particular using spectral decoding, are foreseen for the ANKA storage ring. This will allow to resolve fast changes of bunch deformation and structure during the low alpha operation (2-15 ps rms bunch length). This technique uses a chirped laser pulse to probe the field induced birefringence in an electro optical crystal. The laser pulse is then analyzed in a single shot spectrometer. To obtain the birefringence modulation one can either use the near field of the electron bunch (placing the crystal close to the electron bunch in the UHV system of the storage ring), or the far field (coherent synchrotron radiation in the THz range at a THz-/IR-Beamline). The laser needs to supply: sufficient tunability of pulse length, a wide spectrum to allow for a sub-ps resolution. Additionally it must provide a mode-locked operation synchronized to the bunch revolution clock. For this purpose, a mode locked Ytterbium fibre laser system which operates at 10³⁰ nm has been developed at the Paul-Scherrer Institute in Switzerland. We give an overview over the experimental set up in the ANKA storage ring and the status of the project.

TUPC093

CSR Bunch Length Monitor for XFEL/SPring-8 - SACLA

FEL, electron, synchrotron, synchrotron-radiation

1224

C. Kondo, S. Matsubara, T. Matsumoto
JASRI/SPring-8, Hyogo-ken, Japan
S.I. Inoue, H. Maesaka, Y. Otake
RIKEN Spring-8 Harima, Hyogo, Japan

SPring-8 Angstrom Compact Free Electron Laser (SACLA) is now under commissioning operation, aimed at the generation of a sub-angstrom free electron laser (FEL). In order to ensure the stable FEL generation, non-distractive bunch length monitors utilizing coherent synchrotron radiation (CSR) are installed. The monitors are located at the downstream of individual bunch compressor (BC1-BC3), and they measure the radiation emitted at the individual last magnets of the chicanes. At the magnets, beams with bunch lengths form 10 fs to 1000 fs generate the CSRs with a spectrum ranging the almost whole infrared region (0.03 - 3 THz). The CSRs are detected by a Schottky diode at the BC1, or pyroelectric detectors and a simple organic lens optical system at BC2 and 3. The bunch length monitor systems are used for bunch length feedback control to obtain the stable lasing by changing the rf parameter of acceleration cavities before the BCs. A preliminary system for the above mentioned system was tested at the SCSS test accelerator, and it showed sufficient performance to measure bunch length up to 300 fs. In this report, we describe the design and the results of the first operation.

TUPC101

Generation of Multimode Quasi-monochromatic Terahertz

electron, linac, gun, cathode

1248

K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Generation of quasi-monochromatic terahertz (THz) using multimode Coherent Cherenkov Radiation (CCR) on the order of 0.1 THz was investigated. CCR was generated by a hollow dielectric tube covered by a metal and an electron bunch from a photocathode radio-frequency (RF) gun linac. The intensity and frequency of CCR were measured directly by a Michelson interferometer and a bolometer. The frequency spectra measured by the interferometer indicated sharp peaks close to frequencies of 0.09 THz and 0.14 THz, which corresponded to TM03 and TM04 modes, respectively, according to theoretical calculation for a tube with inner and outer radii of 5 mm and 7 mm. The maximum gain of TM03 mode due to the tube length was obtained as 1.5 dB/cm. The other higher modes, e. g. 0.36 THz (TM09) and 0.40 THz (TM010), were also observed from a 150 mm long tube at a bunch charge of 15 pC, which decreased space charge effect and the bunch length. Finally, a new method for bunch diagnostic based on multimode CCR was proposed. The bunch length was estimated to be 0.45 ps at a bunch charge of 5 pC with the intensity ratio of TM03 to TM09 mode.

TUPC121

Development of MCP Based Photon Detectors for the European XFEL

photon, 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.

TUPC122

Use of a Grid Waveguide for Particle Energy Determination

wakefield

1302

A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: The Education Agency of Russian Federation and the Russian Foundation for Basic Research (09-02-00921).
We consider prospect of use of a grid waveguide for determination of energy of charge particles in bunches. The method under consideration is based on measurement of a waveguide mode frequency. Earlier we developed two variants of this method*. One of them is based on use of a thin dielectric layer in a waveguide. Other variant is based on use of a waveguide loading with a system of wires coated with a dielectric material. In this paper we offer a new version of the method under consideration. It consists in application of a circular waveguide having a grid wall instead a solid one. The grid cells are assumed to be small. The particle bunch moves along the waveguide axis. The analytical solution of the problem is obtained by means of the averaged boundary conditions. It is shown that there is the single propagating mode. The main advantage of the method consists in an enough strong dependency of particle energy on the mode frequency in some wide frequency range. Note as well that this structure is easy for manufacture and can be embedded in the accelerator channel without big difficulty.
* A.V.Tyukhtin et al., PAC’07, p.4156; A.V. Tyukhtin, EPAC’08, p.1302; A.V. Tyukhtin, Tech. Phys. Lett. 35, p.263 (2009); A.V. Tyukhtin et al., IPAC’10, p.10⁷¹.

TUPC126

Indirect Measurement of Power Deposition on the IFMIF/EVEDA Beam Dump by means of Radiation Chambers

neutron, diagnostics, light-ion, cathode

1314

D. Rapisarda, J.M. Arroyo, B. Brañas, A. Ibarra, D. Iglesias, C. Oliver
CIEMAT, Madrid, Spain
F. Ogando
UNED, Madrid, Spain

Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230
The beam stop of the IFMIF/EVEDA accelerator will be a copper cone receiving a total power of ~1 MW, coming from 9 MeV D⁺ at 125 mA. The mechanical stresses in this beam dump come mainly from the thermal gradients generated in the cone, being therefore related with the power deposition profile. Anomalous situations such as beam misalignments or incorrect focusing can lead to variations in this profile outside the normal operation range. These variations must be detected and corrected for beam dump protection. Due to the interaction between D⁺ and the copper cone important neutron and gamma fluxes are generated around the beam dump (10¹⁰ – 10¹¹ n/cm²/s, 10¹⁰ p/cm²/s) with a spatial profile which is directly linked to the power deposition. In this work, a diagnostic based on a set of radiation chambers is proposed to measure on-line this radiation field, giving indirect information about the power deposition on the beam dump. The sensitivity of the radiation field to the power deposition profile is demonstrated and the diagnostic strategy explained, establishing the main specifications and requirements of the detectors.

TUPC127

Optical Transition Radiation System for ATF2

emittance, target, coupling, simulation

1317

J. Alabau-Gonzalvo, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós
IFIC, Valencia, Spain
J. Cruz, D.J. McCormick, G.R. White, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Funding Agency: FPA2010-21456-C02-01 Work supported in part by Department of Energy Contract DE-AC02-76SF00515
In this paper we present the first measurements performed during the fall 2010 and early 2011 runs. Software development, simulations and hardware improvements to the Multi-Optical Transition Radiation System installed in the beam diagnostic section of the Extraction (EXT) line of ATF2 are described. 2D emittance measurements have been performed and the system is being routinely used for coupling correction. Realistic beam simulations have been made and compared with the measurements. A 4D emittance procedure, yet to be implemented, is also discussed. A demagnifier lens system to improve the beam finding procedure has been designed and will be implemented in a future run. Finally, we discuss further verification work planned for the next run period of ATF.

TUPC135

Beam Loss Monitors Comparison at the CERN Proton Synchrotron

beam-losses, injection, electron, proton

1341

S.S. Gilardoni, S. Aumon, E. Effinger, J. Gil Flores
CERN, Geneva, Switzerland
U. Wienands
SLAC, Menlo Park, California, USA

CERN is planning the renovation and upgrade of the beam loss detection system for the Proton Synchrotron (PS). Improved performance in speed–to be able to monitor beam loss on a bunch-by-bunch basis–and in long-term stability–to reduce or avoid the need for periodic calibration–are aimed for. To select the most suitable technology, different detectors were benchmarked in the machine with respect to the same beam loss. The characteristics of the different detectors, the results of the measurement campaign and their suitability as future monitors for the PS are presented.

TUPC147

A Micro-Channel Plate Based Gas Ionization Profile Monitor with Shaping Field Electrodes for the ISIS H⁻ Injector

ion, controls, vacuum, beam-losses

1371

P.G. Barnes, G.M. Cross, B.S. Drumm, S.A. Fisher, S.J. Payne, A. Pertica, C.C. Wilcox
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Beam profile measurements within the ISIS H⁻ injector line are achieved using destructive devices such as moving wire scanners. To avoid damage to the wires, measurements are made with the injector operating on reduced power. This paper reports the development of a Micro-Channel Plate based profile monitor which allows beam measurements to be made under normal operating conditions. The monitor produces profiles by measuring the +ion current resulting from the interaction of the H⁻ beam with the surrounding residual gas. The 32 channel Micro-Channel Plate is mounted on a rotating arm to enable it to be positioned parallel to the beam for calibration (all channels then measure the same +ion current) and perpendicular to the beam for profile measurements. A 15kV drift field is used together with field shaping electrodes to ensure a flat electric field gradient across the monitor, thereby minimising distortion of the profile due to the electric field. This paper details all aspects of the design and construction of this profile monitor. Beam profiles are compared to previous wire scanner results. Shaping field upgrades are discussed to improve the longitudinal field shape.

TUPC153

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

photon, beam-losses, 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.

TUPC168

Results from the LHC BRAN Luminosity Monitor at Increased Luminosities

luminosity, emittance, injection, simulation

1428

R. Miyamoto
BNL, Upton, Long Island, New York, USA
E. Bravin
CERN, Geneva, Switzerland
H.S. Matis, A. Ratti, W.C. Turner, H. Yaver, T. stezelberger
LBNL, Berkeley, California, USA

Funding: This work supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The LHC BRAN luminosity monitors are used to monitor and optimize the luminosity at the LHC high luminosity interaction points IP1 and IP5. The Argon gas ionization chambers detect showers produced in the TAN absorbers by neutral particles emerging from pp collisions. The detectors have been operated during the 2010 run by counting the shower rate. As the current 2011 run has the multiplicity of proton-proton collisions per bunch crossing near ten, the detector sees more than one collision per bunch crossing. Therefore, the operation of the detector has been switched to pulse height mode to detect the average shower flux. This paper presents results from recent pulse height mode measurements, including the total and bunch-by-bunch luminosity as well as a determination of the crossing angle at these IPs. Comparisons with luminosity measurements from ATLAS and CMS are also presented.

TUPC169

Single-shot Electro-optic Sampling of Coherent Transition Radiation at the A0 Photoinjector

laser, polarization, diagnostics, electron

1431

T.J. Maxwell, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J. Ruan, R.M. Thurman-Keup
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC under U.S. Dept. of Energy Contract No. DE-AC02-07CH11359, and Northern Illinois Univ. under US Dept. of Defense DURIP program Contract N00014-08-1-10⁶⁴.
Future collider applications and present high-gradient laser plasma wakefield accelerators operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation (*) or the bunch wakefields (**) with sub-picosecond time resolution. Potential applications in shot-to-shot, non-interceptive diagnostics continue to be pursued for live beam monitoring of collider and pump-probe experiments. Related to our developing work with electro-optic imaging, we present results on single-shot electro-optic sampling of the coherent transition radiation from bunches generated at the A0 photoinjector.
* J. van Tilborg et al., Phys. Rev. Lett. 96, 014801 (2006).
** M. J. Fitch et al., Phys. Rev. Lett. 87 034801 (2001).

TUPC172

Evaluation and Correction of the Non-linear Distortion of CEBAF Beam Position Monitors

electron, simulation, pick-up

1440

M. Spata, T.L. Allison, K.E. Cole, J. Musson, J. Yan
JLAB, Newport News, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The beam position monitors at CEBAF have four antenna style pickups that are used to measure the location of the beam. There is a strong nonlinear response when the beam is far from the electrical center of the device. In order to conduct beam experiments at large orbit excitation we need to correct for this nonlinearity. The correction algorithm is presented and compared to measurements from our stretched wire BPM test stand.

TUPO004

Generation of Attosecond Soft X-ray Pulses in a Longitudinal Space Charge Amplifier

undulator, electron, space-charge, laser

1449

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

A longitudinal space charge amplifier (LSCA), operating in soft x-ray regime, was recently proposed. Such an amplifier consists of a few amplification cascades (focusing channel and chicane) and a short radiator undulator in the end. Broadband nature of LSCA supports generation of few-cycle pulses as well as wavelength compression. In this paper we consider an application of these properties of LSCA for generation of attosecond x-ray pulses. It is shown that a compact and cheap addition to the soft x-ray free electron laser facility FLASH would allow to generate 60 attosecond (FWHM) long x-ray pulses with the peak power at 100 MW level and a contrast above 98%.

TUPO005

Design Optimization for a Non-Planar Undulator for the JETI-Laser Wakefield Accelerator in Jena

undulator, electron, laser, wakefield

1452

V. Afonso Rodriguez, T. Baumbach, A. Bernhard, G. Fuchert, A. Keilmann, P. Peiffer, C. Widmann
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai
IOQ, Jena, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

In a laser wakefield accelerator (LWFA), excited by a femtosecond laser pulse electrons are accelerated to several 100 MeV within a few centimeters. The energy spread of the electron beam is relatively large and varies from shot to shot. In order to obtain monochromatic photons in an undulator despite the energy spread, the following idea was proposed. Two bending magnets and a drift space in between produces dispersion so that particles with different energies have different transverse positions. The beam enters a non-planar undulator, e.g. cylindrical pole geometry, where the K-value also varies with transverse position. If the two variations in the transverse direction (particle energy and K-value) compensate each other the generated light is more monochromatic than with a conventional planar undulator. In this paper such a modified undulator design optimized for the JETI-LWFA in Jena is presented. An experiment to test this concept is in preparation.

TUPO006

Design of a Dispersive Beam Transport Line for the JETI Laser Wakefield Accelerators

undulator, electron, dipole, quadrupole

1455

C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, P. Peiffer
KIT, Karlsruhe, Germany
M. Kaluza, M. Nicolai
IOQ, Jena, Germany
R. Rossmanith
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany

Laser wakeﬁeld accelerators (LWFA) emit electrons with energies of a few 100 MeV at very short bunch lengths while having a compact design. However, electron bunches from LWFA show a larger energy spread than those of conventional accelerators. This is a challenge when using these bunches e.g. to generate radiation in an undulator. A possible strategy to cope with that is to spectrally disperse the bunch and match the resulting spatial distribution with a spatially varying undulator ﬁeld amplitude. For realizing the dispersion a pair of dipole magnets is used. The electrons leaving this dipole chicane have to meet certain requirements imposed by the undulator: In the deﬂection plane the beam has to be collimated and its energy distribution must match the undulator ﬁeld. In the other transversal plane the beam has to be focussed on the center of the undulator keeping the value of the beta function small. To include this in the compact design of the setup, a combination of specially designed quadrupole and sextupole magnets is employed. In this contribution the design of the setup and the results of the particle tracking through this chicane are presented.

TUPO007

FLUTE, a Linac Based THz Source

linac, gun, synchrotron, synchrotron-radiation

1458

S. Naknaimueang, M. Schwarz
Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
R. Abela, H.-H. Braun, R. Ganter, B. Patterson
PSI, Villigen, Switzerland
A.H. Albert, T. Baumbach, M. Hagelstein, N. Hiller, E. Huttel, V. Judin, B. Kehrer, R. Kubat, S. Marsching, W. Mexner, A.-S. Müller, M.J. Nasse, A. Plech, R. Rossmanith, M. Schuh
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

We propose a versatile THz source named FLUTE (“Ferninfrarot Linac- Und Test-Experiment”) based on a 30 - 50 MeV S-band linac with bunch compressor, that shall not only provide high field THz pulses applications but shall also serve as a test facility to study important accelerator physics issues. This is also of importance in view of the planned utltra-broadband THz to mid infrared user facility TBONE. Special emphasis is put on studies of bunch compression and beam stability as a function of bunch charge (0.1-5 nC) and of different generation mechanisms of coherent radiation (CSR, CER, CTR). This paper describes the design and layout of the proposed FLUTE machine and presents results of beam dynamic calculations with the tracking programs ASTRA and CSRtrack.

TUPO009

HiSOR-II, Compact Light Source with an Innovative Lattice Design

emittance, lattice, focusing, synchrotron

1464

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

Funding: This work is partially supported by Cooperative and Supporting Program for Researches and Educations in University sponsored by KEK
We proposed a ring that a beam orbit is not closed with one turn and return to starting point after multiple turns around the ring. The idea of this new accumulation ring was inspired based on the torus knot theory. This ring has a long length of the total closed orbit in comparison with a conventional ring which has the orbit of one turn. Therefore this ring can have many straight sections and is advantageous to installation of insertion devices. We are designing a new ring based on the shape of a (3,11) torus knot for our future plan ‘HiSOR-II’. This ring has 11 long straight sections and can place undulators effectively by placing elements such as quadrupole magnets at the place near bending magnet, outside of the orbit crossing section. Furthermore, this ring has about 3 times longer circumference in comparison with the conventional ring, the diameter of the ring is as compact as 15 m, but its circumference is as long as 130 m. On the other hand, this ring must achieve low emittance to operate as the 3rd generation light source ring. Therefore we designed lattice of this ring in reference to MAX-III and achieved low emittance by using bending magnets with combined function.

TUPO010

An Innovative Lattice Design for a Compact Storage Ring

lattice, storage-ring, synchrotron, synchrotron-radiation

1467

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

Funding: *This work is partially supported by Cooperative and Supporting Program for Researches and Educations in Universities sponsored by KEK.
We propose a new concept of lattice design for a compact light source storage ring. In a ring with this new scheme, the electron beam may have extremely longer design orbit than that of a conventional ring. In this ring, a design orbit closes after completing multiple turns. The lattice for realizing this exotic beam orbit can be made by placing conventional accelerator components such as bending magnets, quadrupole magnets, RF cavity and so forth in an appropriate manner onto a projected torus knot in the horizontal orbit plane. Due to an extended closed orbit length, the ring with this type of lattice has larger maximum stored charge if operated in multiple-bunch mode, and has longer bunch-to-bunch interval if operated in a single-bunch mode. Also, essential for a storage ring as the synchrotron light source, a larger number of straight sections may accommodate with many insertion devices. In addition, this new scheme may provide advantages for designing a oscillator-type free electron laser and coherent radiation light source.

TUPO017

Peculiarities of the Excitation of an Optical Resonator by an Electron Beam

electron, undulator, damping, storage-ring

1479

E.G. Bessonov, M.V. Gorbunkov, A.L. Osipov
LPI, Moscow, Russia
A.A. Mikhailichenko
CLASSE, Ithaca, New York, USA

The peculiarities of the optical resonator excitation by electrons in a FEL based on the Self-Stimulated Undulator Radiation at main and collateral synchronicity conditions are discussed*.
* E.G.Bessonov et al., Self-Stimulated Undulator Radiation and its Possible Applications, http://arxiv.org/ftp/arxiv/papers/10⁰⁹/1009.3724.pdf

TUPO031

The Shielding Design of BERLinPro

neutron, electron, shielding, linac

1503

K. Ott, M. Helmecke
HZB, Berlin, Germany

Funding: Funded by the Bundesministerium für Bildung und Forschung and by the Land Berlin.
The Helmholtz-Zentrum Berlin started in January 2011 the design and construction of the Berlin Energy Recovery Linac Project BERLinPro as a demonstrator of ERL science and technology. BERLinPro consists of a SRF photo injector, a merger, superconducting booster and linac modules, the ring and a beamdump. The energy is 50 MeV, the maximum current is 100 mA (cw), acceleration to higher energies is an option for the future. The low energy parts of the machine are operated at about 10 MeV. Due to the potential radiation hazard posed by the tremendous beampower the facility will be placed subterraneously. The shielding concept is presented here. We used the Monte Carlo code FLUKA to calculate the details of the shielding, activations, energy doses for radiation damage and energy spectra for realistic scenarios. Due to computing time reasons we used FLUKA calculations in the 50 MeV to 1 GeV range to derive analytical formulas for the vertical shielding. Extrapolation of existing formulas valid in the GeV range (or below 100 MeV) are not applicable because of the rapidly increasing cross section of photo pion production between 100 and 200 MeV.

TUPS002

Photodesorption Measurements at ESRF D31

vacuum, synchrotron, synchrotron-radiation, electron

1518

H.P. Marques, G. Debut, M. Hahn
ESRF, Grenoble, France

Since 1998 exists at ESRF a dedicated beamline for photodesorption measurement from vacuum chambers - D31. The original goal of this installation was to study the wall pumping effect. When exposed to synchrotron radiation surfaces exhibit strong outgassing of the adsorbed gas layer despite UHV conditions. Long term outgassing leads to the depletion of the adsorbed layer and produces a very clean surface which turns the walls of the vacuum chamber into an active pumping surface. The desorption mechanisms can be described by the long standing models of Knotek-Feibelman (KF) and Menzel-Gomer-Redhead – (MGR) which are themselves encompassed under the name of Desorption Induced by Electronic Transitions (DIET). In these models the surface itself plays a fundamental role in the desorption mechanism. At D31 have been tested chambers of stainless steel, aluminum and copper, with or without coatings (e.g. NEG, copper), designed by ESRF and other institutes like ALBA, CERN, ELETTRA and Soleil. Here we review some of the results obtained and outline the future plans of D31.

TUPS008

The Gas Attenuator Vacuum System of FERMI@Elettra

vacuum, photon, 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.

TUPS016

Vacuum System Design for the MAX IV 3 GeV Ring

vacuum, storage-ring, synchrotron, lattice

1554

E. Al-dmour, D. Einfeld, J. Pasquaud, M. Quispe
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
J. Ahlbäck, M.J. Grabski, P.F. Tavares
MAX-lab, Lund, Sweden

We describe the conceptual design of the vacuum system of the 3 GeV electron storage ring in the MAX IV facility currently under construction in Lund, Sweden. The standard vacuum chambers are for the most part a cylindrical copper tube with 11 mm inner radius whereas stainless steel will be used at selected locations for beam position monitors, bellows and corrector vacuum chambers. In order to cope with the low vacuum conductance, distributed pumping will be provided through NEG coating of all chambers, including those in dipole magnets making MAX IV the first storage ring to be fully NEG coated. We present the mechanical and thermal design of these chambers and discuss the challenges involved in extracting insertion device radiation as well as coping with the heat load from both IDs and bending magnets in a machine with large bending radius, narrow chambers and tight mechanical tolerance requirements.

TUPS019

Synchrotron Radiation in the LHC Vacuum System

photon, vacuum, dipole, 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.

TUPS025

Design of a Highly Optimised Vacuum Chamber Support for the LHCb Experiment

vacuum, background, interaction-region, collider

1581

L. Leduc, G. Corti, R. Veness
CERN, Geneva, Switzerland

The beam vacuum chamber in the LHCb experimental area passes through the centre of a large aperture dipole magnet. The vacuum chamber and all its support systems lie in the acceptance of the detector, so must be highly optimised for transparency to particles. As part of the upgrade programme for the LHCb vacuum system, the support system has been re-designed using advanced lightweight materials. In this paper we discuss the physics motivation for the modifications, the criteria for the selection of materials and tests performed to qualify them for the particular environment of a particle physics experiment. We also present the design of the re-optimised support system.

TUPS032

Overview of EuCARD Accelerator and Material Research at GSI

ion, collimation, heavy-ion, quadrupole

1602

J. Stadlmann, H. Kollmus, E. Mustafin, N. Pyka, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann
GSI, Darmstadt, Germany
L.H.J. Bozyk
TU Darmstadt, Darmstadt, Germany

Funding: EuCARD is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 227579
EuCARD is a joined accelerator R&D initiative funded by the EU. Within this program, GSI Darmstadt is performing R&D on materials for accelerators and collimators in WP8(ColMat). GSI covers prototyping and testing of a cryogenic ion catcher for FAIR's main synchrotron SIS100, simulations and studies on activation of accelerator components e.g. halo collimatiors as well as irradiation experiments on materials foreseen to be used in FAIR accelerators and the LHC upgrade program. Carbon-carbon composites, silicon carbide and copper-diamond composite samples have been irradiated with heavy ions at various GSI beamlines and their radiation induced property changes were characterized. Numerical simulations on the possible damage by LHC and SPS beams to different targets have been performed. Simulations and modelling of activation and long term radiation induced damage to accelerator components have started. A prototype ion catcher has been built and first experiments have been performed in 2011. New collaborations with other institutes and industry in the EuCARD framework have been established and findings of the joined R&D effort influence decisions in the FAIR project and LHC upgrade.

TUPS034

Development and Construction of the Beam Dump for J-PARC Hadron Hall

hadron, proton, gun, status

1608

A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, R. Muto, M. Naruki, Y. Sato, S. Sawada, Y. Shirakabe, Y. Suzuki, H. Takahashi, M. Takasaki, K.H. Tanaka, A. Toyoda, H. Watanabe, Y. Yamanoi
KEK, Tsukuba, Japan
H. Noumi
RCNP, Osaka, Japan

Funding: This work is supported by Grant-in-Aid (No.22740184) for Young Scientists (B) of the Japan Ministry of Education, Culture, Sports, Science and Technology [MEXT].
A facility of Hadron hall at Japan Proton Accelerator Research Complex (J-PARC) had been constructed in June 2007. Hadron hall is designed to handle intense slow-extraction proton beam from the main accelerator of J-PARC, i.e. 50-GeV-PS. The first transportation of the proton beam to the hall was successfully made in Jan. 2009. A beam dump constructed at the end of the primary proton beam line in Hadron hall is designed to safely absorb 15 μA (=750-kW) proton beam. Its central core of the dump is made of copper with water cooling and is surrounded by iron and concrete for radiation protection. We made thermal and mechanical FEM analysis for investigating heat generation and mechanical stress from energy deposition. We also made cooling experiments for measuring heat transfer coefficient of candidates for new cooling device. As a result, the adopted device has direct cooling paths which are prepared as long holes made by Gun Drill from the outer surface of the copper core. In addition, the beam dump is designed to safely move to 50-m downstream as one body for future expansion of Hadron hall. This paper reports development and construction of the beam dump in Hadron hall.

TUPS035

LHC Collimators with Embedded Beam Position Monitors: A New Advanced Mechanical Design

alignment, collimation, pick-up, simulation

1611

A. Dallocchio, A. Bertarelli, C.B. Boccard, F. Carra, M. Gasior, L. Gentini, M.A. Timmins
CERN, Geneva, Switzerland

The LHC collimation system, ensuring both functions of beam cleaning and machine protection, is potentially submitted to high-energy beam impacts. Currently the collimators setup is performed by monitoring beam losses generated by the collimator jaws when approaching the particle beam. This procedure is applied to all LHC collimators (almost one hundred), taking several hours, and needs to be repeated if beam settings change significantly. Furthermore, during the beam-based alignment, the LHC tertiary collimators are potentially exposed to abnormal losses entailing possible damage to their tungsten jaws. To improve the efficiency of the machine operation and better control the particle beam a new advanced design embedding Beam Position Monitors (BPM) into the movable collimator jaws has been developed. This paper describes the mechanical design of various types of future collimators with embedded BPMs. Experimental measurements performed on a simplified functional prototype installed in the CERN SPS showed that, thanks to on-board BPMs, the collimator could be precisely, rapidly, and safely aligned and the beam position accurately measured.

TUPS038

Design of a Beam Dump for 3 to 100 MeV for the New H⁻ Beam in the CERN Linac4

linac, vacuum, proton, ion

1620

C. Maglioni
CERN, Geneva, Switzerland

In this paper the design of a beam dump for the energy range from 3 to 100 MeV is reported. The dump is developed as temporary dump for the commissioning phase of the Linac4 Project, under construction at CERN, and will be installed in different periods to withstand a beam of different intensities and energies, following the chronological assembly of the linac. The dump design and its functionalities, as well as material choice, criticalities and cooling system are described. Finally, the results from the numerical and analytical thermo-mechanical analyses are reported, while the use of the dump also at 160 MeV is investigated.

TUPS039

Reduction of Magnetic Interference on the Position Sensors of the LHC Collimators

shielding, simulation, dipole

1623

A. Masi, M. Lamberti, R. Losito, M. Martino
CERN, Geneva, Switzerland

The jaws of the LHC collimators have to be positioned with respect to the beam with an accuracy of 20 μm. On some collimators, installed in the LHC transfer lines from SPS, huge reading errors of several tens of micrometers have been observed on the Linear Variable Differential Transformer (LVDT) positioning sensors in synchronization with the variable magnetic field produced by the feed cables of the pulsed resistive dipoles of the transfer line. In this paper we introduce and describe in detail the problem, the model developed using FLUXTM for the simulation of the magnetic flux density generated by the current cables in the complex environment of an LHC transfer line, and the magnetic shielding we designed and implemented. Finally, we compare the results of simulations with experimental measurements taken during on-line pulsed magnets test campaigns.

TUPS040

Driving the LHC Collimators' Stepping Motors over 1 km with High Accuracy avoiding EMI Effects

controls, feedback, impedance, beam-losses

1626

A. Masi, G. Conte, R. Losito, M. Martino
CERN, Geneva, Switzerland

The LHC collimators are exposed to very high levels of radiation, which means that the power drivers must be installed far from the stepping motors that they drive. Due to the geometry of the underground installations, the distances can be up to 1 km. The long cables that connect the drivers to the motors behave as transmission lines modifying dramatically the impedance seen by the drivers and consequently jeopardizing the control performance of Pulse Width Modulation (PWM) drivers. In this paper we address this problem, provide an analytical model of the driver-cable-motor system and describe the analog solution we have developed to improve the performance of a typical off the shelf driver. Finally we characterize the improvement of the performances with measurements of positioning repeatability and show that electromagnetic emissions from the long cables are drastically reduced, making the use of stepping motors compatible with extremely sensitive instrumentation such as the LHC Beam Loss Monitors (BLM).

TUPS041

Thermo-mechanical Study of a CLIC Bunch Train hitting a Beryllium Energy Spoiler Model

collimation, wakefield, simulation, linac

1629

J.-L. Fernández-Hernando, D. Angal-Kalinin
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

A thermo-mechanical study of the impact a CLIC bunch train has over a beryllium energy spoiler has been made. Beryllium has a high electrical and thermal conductivity which together with a large radiation length compared to other metals makes it an optimal candidate for a long tapered design spoiler that will not generate high wakefields, which might degrade the orbit stability and affect the collider luminosity. This paper shows the progress made from the paper presented last year in IPAC 2010. While in the aforementioned paper the study of the temperature and stress was made for the duration of the bunch train this time the study shows the evolution of the stress in the spoiler body 3 microseconds after the bunch train hit.

TUPS045

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

shielding, photon, 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.

TUPS048

Equipment and Techniques for the Replacement of the ISIS Proton Beam to Target Window

target, shielding, proton, neutron

1638

S.D. Gallimore, S.J.S. Jago
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Spallation Neutron Source has been in operation at the Rutherford Appleton Laboratory for over 25 years. Much of the original equipment installed during the construction of the facility is still in operation. The window separating the proton beam transfer line from the neutron target is a key component in the accelerator complex. During the operational life of the Beam Entry Window it has absorbed a considerable amount of energy deposited from the proton beam as it passes from the accelerator vacuum to the target area. Due to the difficulties in accessing and handling the window assembly, a decision was made to replace this component in a planned maintenance period. This paper describes the specialist remote handling equipment and techniques that were developed during the 3 year build up to the removal and replacement of the of the highly active Beam Entry Window.

TUPS053

A Target Magnet System for a Muon Collider and Neutrino Factory

shielding, target, factory, collider

1650

H.G. Kirk
BNL, Upton, Long Island, New York, USA
V.B. Graves
ORNL, Oak Ridge, Tennessee, USA
K.T. McDonald
PU, Princeton, New Jersey, USA
N. Souchlas, R.J. Weggel
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: This work is supported in part by the US DOE Contract NO. DE-AC02-98CH10886.
The target system envisioned for a Muon Collider or Neutrino Factory includes a 20-T solenoid field surrounding a mercury jet target with the field tapering to 1.5 T 15 m downstream of the target. A principal challenge is to shield the superconducting magnets from the radiation issuing from the 4-MW proton beam impacting the target. We describe a solution which will deliver the desired field while being capable of tolerating the intense radiation environment surrounding the target.

TUPS058

HiRadMat: A New Irradiation Facility for Material Testing at CERN

proton, target, ion, vacuum

1665

I. Efthymiopoulos, S. Evrard, H. Gaillard, D. Grenier, C. Heßler, M. Meddahi, A. Pardons, C. Theis, P. Trilhe, H. Vincke
CERN, Geneva, Switzerland
N. Charitonidis
EPFL, Lausanne, Switzerland

HiRadMat (High Irradiation to Materials) is a new facility under construction at CERN designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of 7.2 μs, to a maximum pulse energy of 3.4 MJ. In addition to protons, ion beams with an energy of 173.5 GeV/nucleon and a total pulse energy of 21 kJ can be used. The facility is expected to become operational in autumn 2011. The first tests will include candidate materials and prototype assemblies of LHC collimators foreseen to operate at the ultimate LHC beam powers. Experiments on beam windows and high-power target material options, such as tungsten powder, are also planned. The paper will describe the layout and design parameters for the facility and the way experiments can be operated. Ideas on online and post-irradiation tests and instrumentation will be outlined.

TUPS059

SPS WANF Dismantling: A Large Scale-Decommissioning Project at CERN

shielding, target, feedback, ion

1668

S. Evrard, Y. Algoet, N. Conan, D. DePaoli, I. Efthymiopoulos, S. Fumey, H. Gaillard, J.L. Grenard, D. Grenier, A. Pardons, E. Paulat, Y.D.R. Seraphin, M. Tavlet, C. Theis, H. Vincke
CERN, Geneva, Switzerland

The operation of the SPS (Super Proton Synchrotron) West Area Neutrino Facility (WANF) was halted in 1998. In 2010 a large scale-decommissioning of this facility was conducted. Besides CERN’s commitment to remove non-operational facilities, the additional motivation was the use of the installation (underground tunnels and available infrastructure) for the new HiRadMat facility, which is designed to study the impact of high-intensity pulsed beams on accelerator components and materials. The removal of 800 tons of radioactive equipment and the waste management according to the ALARA (As Low As Reasonably Achievable) principles were two major challenges. This paper describes the solutions implemented and the lessons learnt confirming that the decommissioning phase of a particle accelerator must be carefully studied as from the design stage.

TUPS063

Power Saving Schemes in the NSRRC

controls, synchrotron, synchrotron-radiation, status

1680

J.-C. Chang, Y.F. Chiu, J.-M. Lee, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan will complete the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in the end of 2012. The power consumption of the TPS is estimated about 2.3 times of that of the existed Taiwan Light Source (TLS). To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include power requirement control, optimization of chillers operation, application of heat pump, air conditioning system improvement, power factor improvement and the lighting system improvement.

TUPS066

Design of Front End Safety Interlock System for Taiwan Photon Source

controls, photon, 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, photon, simulation, vacuum

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.

TUPS071

Performance of the Protection System for Superconducting Circuits during LHC Operation

power-supply, extraction, interlocks, instrumentation

1701

R. Denz, Z. Charifoulline, K. Dahlerup-Petersen, R. Schmidt, A.P. Siemko, J. Steckert
CERN, Geneva, Switzerland

The protection system for superconducting magnets and bus-bars is an essential part of the LHC machine protection and ensures the integrity of substantial elements of the accelerator. Due to the large amount of hardwired and software interlock channels the dependability of the system is a critical parameter for the successful exploitation of the LHC. The paper will report on observed failure modes, present fault statistics and discuss the overall performance of the protection system during LHC operation in 2010 and 2011. Foreseen measures for further improvements and operational results obtained with already implemented system upgrades will be described.

TUPS072

Performance of the Arc Detectors of LHC High Power RF System

cavity, klystron, plasma, ion

1704

D. Valuch, O. Brunner, N. Schwerg
CERN, Geneva, Switzerland

During operation, the LHC high power RF equipment, such as klystrons, circulators, waveguides and couplers have to be protected from damage caused by electromagnetic discharges. Once ignited these arcs grow over the full height of the waveguide and travel towards the RF source. The burning plasma can cause serious damage to the metal surfaces or ferrite materials. The LHC arc detector system is based on the optical detection of the discharge through small apertures in the waveguide walls. The light is guided by means of an optical fibre from the view port to a photo diode. Experience shows that some of the currently used optical fibers suffer from x-ray induced opacity. The sensors are also exposed to the radiation produced by secondary showers coming from the high intensity beams which, if not treated properly, can cause frequent spurious trips. In the second half of the paper we presents a number of improvements to the design. Measurements with optical parameters from real arcs and a fiber-less version of the detector with redundant detectors for critical environments.

TUPS084

Development Status of PPS, MPS and TS for IFMIF/EVEDA Prototype Accelerator

controls, status, beam-losses, monitoring

1734

H. Takahashi, T. Kojima, T. Narita, K. Nishiyama, H. Sakaki, K. Tsutsumi
JAEA, Aomori, Japan

Control System for IFMIF/EVEDA* prototype accelerator consists of six subsystems; Central Control System (CCS), Local Area Network (LAN), Personnel Protection System (PPS), Machine Protection System (MPS), Timing System (TS) and Local Control System (LCS). The IFMIF/EVEDA prototype accelerator provides deuteron beam with the power more than 1 MW, which is as same as that in cases of J-PARC and SNS. Then, the PPS is required to protect technical and engineering staff against unnecessary exposure and the other danger phenomena. The MPS and the TS are strongly required a high performance and precision to avoid radio-activation of the accelerator components. To realize these requirements, the PPS designed that Programmable Logic Controllers (PLCs) are used mainly, and a sequence is programmed for entering and leaving of controlled area and etc. Hardware and logic sequences for the MPS are designed to realize the beam inhibition time within 30 micro-seconds. The TS prototype modules were designed and tested using 10 MHz master clock and 100 Hz reference trigger. This article presents the PPS, MPS and TS design in details.
* International Fusion Material Irradiation Facility / Engineering Validation and Engineering Design Activity

TUPS086

Ultra-high Resolution Observation Device for Carbon Stripper Foil

monitoring, vacuum, scattering, proton

1740

Y. Takeda, Y. Irie, I. Sugai
KEK, Ibaraki, Japan

To observe a growth process of a pinhole on a HBC-foil due to beam irradiation, an up to 10 um of device for ultra-high resolution observation is needed. For the environment where we use the device for observation is so severe as under high radiation and in vacuum, there is no device available for long-time observation. Then, we designed and created a wholly new method based system which enables constant observation by ultra-high resolution even under high radiation environment. We attempted several experiments, compared materials usable under radiation environment, checked up various optical systems which enables high resolution, and finally developed the best method. As a result, we successfully invented an ultra-high resolution observation device available for monitoring an object about 8 meters distant by 8.3um resolution.

TUPS089

HI-13 Tandem Accelerator Radiation Protection System

controls, tandem-accelerator, monitoring, status

1749

X.F. Wang, Y.M. Hu
CIAE, Beijing, People's Republic of China

In HI-13 Tandem Accelerator laboratory, a new radiation protection system has been built Which composed of 7 protective door control units and 7 emergency alarms , 23 groups of indicators,17 groups of workshop-empty units , L.E and IMAG Faraday cups as well as computer control and display system . Pre-empty process is prerequisite before close the protective doors to ensure nobody be exposed on irradiation environment otherwise the door-open would be disabled. Even thought somebody left, pushing nearby alarm button and emergency door-open button will induce glittery signal and simultaneous door-openning. L.E and IMAG Faraday cups execute immediate beam interruption once accidence occured . The distributed indicators indicate real time status of all the work fields. All above devices and units are interlocked follow some complex but logical protective rules. Computer workstation is built and accordingly, after full information and operation action signals are collected and transferred, the software can complete full-sides status monitoring, provide convenient control and display interfaces as well as pop adequate prompt frames.

TUPS102

Design of an FPGA-based Radiation Tolerant Agent for WorldFIP Fieldbus

controls, target, simulation, status

1780

G. Penacoba Fernandez, P. Alvarez, E. Gousiou, S.T. Page, J.P. Palluel, J. Serrano, E. Van der Bij
CERN, Geneva, Switzerland

CERN makes extensive use of the WorldFIP field-bus interface in the LHC and other accelerators in the pre-injectors chain. Following the decision of the provider of the components to stop the developments in this field and foreseeing the potential problems in the subsequent support, CERN decided to purchase the design information of these components and in-source the future developments using this technology. The first in-house design concerns a replacement for the MicroFIP chip whose last version was manufactured in an IC feature size found to be more vulnerable to radiation of high energy particles than the previous versions. NanoFIP is a CERN design based on a Flash FPGA implementing a subset of the functionality allowed by the communication standard, fitting the requirements of the different users and including the robustness against radiation as a design constraint. The development presented involved several groups at CERN working together in the framework of the Open Hardware Repository collaboration, and aiming at maximizing the interoperability and reliability of the final product.

TUPZ014

Luminosity Optimization for a Higher-Energy LHC

emittance, luminosity, damping, proton

1831

C.O. Domínguez, F. Zimmermann
CERN, Geneva, Switzerland

A Higher-Energy Large Hadron Collider (HE-LHC) is an option to further push the energy frontier of particle physics beyond the present LHC. A beam energy of 16.5 TeV would require 20-T dipole magnets in the existing LHC tunnel, which should be compared with 7 TeV and 8.33 T for the nominal LHC. Since the synchrotron radiation power increases with the fourth power of the energy, radiation damping becomes significant for the HE-LHC. It calls for transverse and longitudinal emittance control vis-à-vis beam-beam interaction and Landau damping. The heat load from synchrotron radiation, gas scattering, and electron cloud also increases with respect to the LHC. In this paper we discuss the proposed HE-LHC beam parameters; the time evolution of luminosity, beam-beam tune shifts, and emittances during an HE-LHC store; the expected heat load; and luminosity optimization schemes for both round and flat beams.

WEOAB03

The Production of High Quality Electron Beams in the ALPHA-X Laser Wakefield Accelerator

electron, laser, plasma, emittance

1956

S.M. Wiggins, M.P. Anania, C. Aniculaesei, E. Brunetti, S. Cipiccia, B. Ersfeld, M.R. Islam, R.C. Issac, D.A. Jaroszynski, G.G. Manahan, R.P. Shanks, G.H. Welsh
USTRAT/SUPA, Glasgow, United Kingdom
W.A. Gillespie
University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
A. MacLeod
UAD, Dundee, United Kingdom

Funding: The U.K. EPSRC, the EC's Seventh Framework Programme (LASERLAB-EUROPE / LAPTECH, grant agreement no. 228334) and the Extreme Light Infrastructure (ELI) project.
The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme is developing laser-plasma accelerators for the production of ultra-short electron beams as drivers of incoherent and coherent radiation sources from plasma and magnetic undulators. Here we report on the latest laser wakefield accelerator experiments on the University of Strathclyde ALPHA-X accelerator beam line looking at high quality electron beams. ALPHA-X uses a 26 TW Ti:sapphire laser (energy 900 mJ, duration 35 fs) focused into a helium gas jet (nozzle length 2 mm) to generate high quality monoenergetic electron beams with central energy in the range 80-180 MeV. The beam is fully characterized in terms of the charge, bunch length, energy spread and transverse emittance. The energy spectrum (with less than 1% measured energy spread) is obtained using a high resolution magnetic dipole imaging spectrometer while pepper-pot mask measurements show that the normalized transverse emittance is as low as 1.1 pi mm mrad (resolution limited). The conditions needed to obtain this high quality are discussed.

Slides WEOAB03 [2.904 MB]

WEYB01

Diagnostics for Ultra-low Emittance Beams

laser, polarization, emittance, optics

1959

J.W. Flanagan
KEK, Ibaraki, Japan

The achievement in recent years of beams with vertical emittance of a few pico-meters in a number of electron storage rings has presented challenges for diagnostics capable of beam size measurements in this regime. A number of different approaches have been developed for various machines (e.g. laser wire; interferometer; Shintake monitor; coded aperture; compound refractive lens). This presentation will review and compare the different methods, and discuss their strengths, weaknesses, ultimate limitations, and the situations where they might be appropriate; and consider possible future directions.

Slides WEYB01 [2.553 MB]

WEOBB01

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

electron, photon, 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]

WEOBB03

Electron Bunch Profile Diagnostics in the Few fs Regime using Coherent Smith-Purcell Radiation

electron, diagnostics, vacuum, linac

1970

N. Delerue
LAL, Orsay, France
R. Bartolini, G. Doucas, K. Pattle, C. Perry, A. Reichold, R. Tovey
JAI, Oxford, United Kingdom

Funding: John Fell Fund, University of Oxford
The rapid developments in the field of laser-driven particle acceleration hold the prospect of intense, highly relativistic electron bunches that are only a few fs long. The determination of the temporal profile of such a bunch presents new challenges. The use of a radiative process such as Smith-Purcell radiation (SPR), whereby the beam is made to radiate a small amount of e/m radiation and the temporal profile is then reconstructed from the measured spectral distribution of the radiation, is particularly promising in this respect. We summarize the advantages of SPR and present the design parameters of a forthcoming experiment at the FACET facility at SLAC with bunch lengths of the order of 60fs rms. We also discuss a new approach to the problem of the recovery of the ‘missing phase’, which is essential for the accurate reconstruction of the bunch profile.

Slides WEOBB03 [4.627 MB]

WEIB04

Accelertor-based Mega-science Projects in China and Their Impact on Economy

linac, vacuum, ion, electron

1986

C. Zhang
IHEP Beijing, Beijing, People's Republic of China

Along with the rapid development of national economy in China, a number of accelerator based mega-science projects were constructed, such as the Beijing Electron-Positron Colliders (BEPC) and its major upgrade project (BEPCII), the Hefei Light Source (HLS), the Heavy Ion Research Facility in Lanzhou (HIRFL) and its Cooling Storage Rings (HIEFL-CSR), the Shanghai Synchrotron Radiation Facility (SSRF) and the Dragon-I induction linac. The Beijing Radioactive Ion Facility (BRIF) and the China Spallation Neutron Source (CSNS) are under construction. In this paper, China’s accelerator projects are briefly reviewed and applications of accelerators are reported. The paper emphasizes spinoff of the accelerator technology developed during R&D and construction of the projects. Collaboration between academia and industry on the projects are described. With some examples, the benefits experienced in the laboratory-industry collaboration and approach of its economic impact are illustrated.

Slides WEIB04 [14.012 MB]

WEPC036

Coherent Synchrotron Radiation Source Based on an Isochronous Accumulator Ring with Femtosecond Electron Bunches

betatron, linac, gun, lattice

2085

N.Y. Huang
NTHU, Hsinchu, Taiwan
H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, F. Miyahara, T. Muto, K. Nanbu, Y. Tanaka
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
W.K. Lau
NSRRC, Hsinchu, Taiwan

A compact isochronous accumulator ring has been studied as a source of coherent synchrotron radiation (CSR) at a wavelength region from THz to GHz. Since the thermionic rf gun is substantially stable in general, we anticipate a bunch train of very short electron pulses can be provided satisfactorily by means of velocity bunching. Careful numerical simulations show possibility of the bunch length of much less than 100 fs with a bunch charge of 20 pC, which will contain sufficiently large form factor for production of CSR at the wavelengths longer than ~ 0.1 mm. The coherent THz radiation of high average power will be achieved if the short bunches can be circulated in the accumulator ring without bunch lengthening. This paper will describe the optimization of thermionic injector to produce femtosecond bunches in addition to study of the lattice designing of complete isochronous optics for the accumulator ring.

WEPC095

Simulations of the Microbunching Instability at ANKA using a Vlasov-Fokker-Planck Solver

electron, synchrotron, simulation, impedance

2232

M. Klein, A.-S. Müller
KIT, Karlsruhe, Germany
K.G. Sonnad
CLASSE, Ithaca, New York, USA

In order to produce coherent synchrotron radiation the ANKA light source is operated frequently in short bunch mode. It is known that during this procedure strong self fields caused by high electron densities can enforce initial density fluctuations and thus lead to microbunching. The build-up of those substructures is accompanied by bursting radiation which provides higher radiation power for the users. Damping and diffusion due to incoherent radiation smoothens the bunch shape again and hence lead to periodic or chaotic bursting cycles. The evolution of the electron bunch density under the influence of self fields can be described by the Vlasov-Fokker-Plank (VFP) equation. We present results from a numerical solution of the VFP-equation for parameters used in standard short bunch mode at ANKA.

WEPC108

CSR Impedance for an Ultrarelativistic Beam moving in a Curved Trajectory

impedance, shielding, vacuum, resonance

2268

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

A dedicated computer code, CSRZ, has been developed to calculate the coherent synchrotron radiation (CSR) impedance for an ultrarelativistic beam moving in a curved trajectory. Following the pioneering work of T. Agoh and K. Yokoya*, the code solves the parabolic equation in the frequency domain in a curvilinear coordinate system. The beam is assumed to move along a vacuum chamber which has a uniform rectangular cross section but with variable bending radius. Using this code, we did investigations in calculating the longitudinal CSR impedance of a single and a series of bending magnets. The calculation results indicate that the shielding effect due to outer chamber wall can be well explained by a simple optical approximation model at high frequencies. The CSR fields reflected by the outer wall may interfere with each other in a long bending magnet and lead to sharp narrow peaks in the CSR impedance.
* T. Agoh and K. Yokoya, Phys. Rev. ST Accel. Beams, 7(5):054403 (2004).

WEPC135

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

vacuum, electron, pick-up, photon

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.

WEPC137

Undulator Radiation Simulation by QUINDI

undulator, electron, simulation, polarization

2316

D. Schiller, E. Hemsing, J.B. Rosenzweig
UCLA, Los Angeles, California, USA

QUINDI, a code developed to simulate coherent emission from bending systems, has been upgraded to include undulators as a beamline element. This approach allows us to better model the radiation produced by a relativistic electron bunch propagating through such a device.

WEPC163

A New Embedded Radiation Monitor System for Dosimetry at the European XFEL

undulator, neutron, controls, linac

2364

F. Schmidt-Föhre, D. Nölle, R. Susen, K. Wittenburg
DESY, Hamburg, Germany
L. Fröhlich
ELETTRA, Basovizza, Italy

The upcoming European XFEL will be built at a length of approx. 3.4 km between the campus of the Deutsches Elektronen-Synchrotron DESY at Hamburg and Schenefeld at Schleswig-Holstein for commissioning in 2015. The XFEL utilizes various electronic systems for machine control, diagnostics and safety. To achieve a cheap and compact accelerator construction, the beam pipe and its nearby electronic supply systems are located inside the same tunnel, charged by an evident amount of radiation in certain sections of the XFEL. To insure the lifecycle and function of electronics and magnetic structures like undulators in these XFEL radiation fields, all electronic systems located inside the tunnel will be sufficiently shielded according to pre-estimated radiation levels. In addition, these electronics and the undulator parts will be monitored for the impact of Gamma- and Neutron-radiation by a new versatile and compact radiation monitor system. It measures the accumulated dose in the electronic cabinets along the XFEL to ensure an exchange of radiated parts before significant radiation damage occurs. First prototype measurements at different radiation sources will be presented.

WEPC164

First Operation of a Fiber Beam Loss Monitor at the SACLA FEL

undulator, beam-losses, vacuum, electron

2367

X.-M. Maréchal, T. Itoga
JASRI/SPring-8, Sayo-gun, Japan
Y. Asano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.

WEPC165

Monte Carlo Simulation of the Total Dose Distribution around the 12 MeV UPC Race-track Microtron and Radiation Shielding Calculations

shielding, simulation, target, beam-losses

2370

C. de la Fuente, M.A. Duch, Yu.A. Kubyshin
UPC, Barcelona, Spain
V.I. Shvedunov
MSU, Moscow, Russia

The Technical University of Catalonia is building a miniature 12 MeV electron race-track microtron for medical applications. In the paper we study the leakage radiation caused by beam losses inside the accelerator head, as well as the bremstrahlung radiation produced by the primary beam in the commissioning setting. Results of Monte Carlo simulations using the PENELOPE code are presented and two shielding schemes, global and local, are studied. The obtained shielding parameters are compared with estimates based on international recommendations of the radiation safety standards.

WEPC166

Licensing and Safety Issues of the ESS Accelerator

shielding, target, beam-losses, neutron

2373

P.E.T. Jacobsson, M. Brandin, D. Ene, T. Hansson
ESS, Lund, Sweden

The licensing process for the European Spallation Source (ESS) has started up. The process includes both an application to the Environmental Court in Sweden as well as the application towards the Swedish Radiation Protection Authority (SSM). The applications will be based on an Environmental Impact Assessment EIA) and a Safety Analysis Report (SAR). One important step has been to define which regulations that apply for ESS. ESS has also set up General Safety Objectives (GSO). Based on the GSO and the legal requirements, the process design of the whole ESS facility is ongoing. This paper will focus upon the radiation safety issues related to the accelerator. This includes items as radiation shielding, personal protection system and operation emissions. Analyses and calculations, based on a preliminary design and layout of the ESS accelerator, will be presented. Discussion is made on issues like shielding material, shielding design and analysis models.

WEPC176

Beam Loss Monitoring and Machine Protection System Design and Application for the ALICE Test Accelerator at Daresbury Laboratory

beam-losses, monitoring, dipole, simulation

2400

S.R. Buckley, J.-L. Fernández-Hernando
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

ALICE is a demonstrator accelerator system which has been designed and built at Daresbury Laboratory. The heart of this facility is an ERL accelerator and a powerful multi-terrawatt laser. It serves as an advanced test facility for novel accelerator and photon science applications. Beam loss monitoring and machine protection systems are vital areas for the successful operation of ALICE. These systems are required, both for efficient machine set up and for hardware protection during operation. This paper gives an overview of the system design, commissioning details and a summary of the systems’ effectiveness as a diagnostic tool.

WEPO033

Update on the Modification and Testing of the MICE Superconducting Spectrometer Solenoids*

solenoid, magnet-design, emittance, focusing

2469

S.P. Virostek, M.A. Green, N. Li, T.O. Niinikoski, H. Pan, S. Prestemon, M.S. Zisman
LBNL, Berkeley, California, USA
A. Langner
CERN, Geneva, Switzerland

Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231.
The Muon Ionization Cooling Experiment (MICE) is an international effort sited at Rutherford Appleton Laboratory, which will demonstrate ionization cooling in a segment of a realistic cooling channel using a muon beam. A pair of identical, 3-m long spectrometer solenoids will provide a 4-tesla uniform field region at each end of the cooling channel. The emittance of the beam as it enters and exits the cooling channel will be measured within the 400 mm diameter magnet bores. The magnets incorporate a three-coil spectrometer magnet section and a two-coil section that matches the solenoid uniform field into the MICE cooling channel. The cold mass, radiation shield and leads are kept cold by means of a series of two-stage cryocoolers and one single-stage cryocooler. Previous testing of the magnets had revealed several operational issues related to heat leak and quench protection. A quench analysis using Vector Fields software and detailed heat leak calculations have been carried out in order to assess and improve the magnet design. Details of the analyses and resulting magnet design modifications along with an update of the magnet assembly and testing progress will be presented here.

WEPO035

Thermal Performance of the S1-Global Cryomodule for ILC

cavity, cryomodule, linac, vacuum

2472

N. Ohuchi, M. Akemoto, S. Fukuda, K. Hara, H. Hayano, N. Higashi, E. Kako, Y. Kojima, Y. Kondo, T. Matsumoto, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Saeki, M. Satoh, T. Shidara, T. Shishido, T. Takenaka, A. Terashima, N. Toge, K. Tsuchiya, K. Watanabe, S. Yamaguchi, A. Yamamoto, Y. Yamamoto, K. Yokoya
KEK, Ibaraki, Japan
T.T. Arkan, S. Barbanotti, H. Carter, M.S. Champion, A. Hocker, R.D. Kephart, J.S. Kerby, D.V. Mitchell, T.J. Peterson, Y.M. Pischalnikov, M.C. Ross
Fermilab, Batavia, USA
A. Bosotti, C. Pagani, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
D. Kostin, L. Lilje, A. Matheisen, W.-D. Möller, N.J. Walker, H. Weise
DESY, Hamburg, Germany

The S1-Global program is the international research collaboration among INFN, FNAL, DESY, SLAC and KEK as one of the GDE R&D for construction of ILC. The S1-Global cryomodule consists of two half-size cryomodules of 6 meter. One was designed by IFNF, and it contained two FNAL cavities and two DESY cavities. The associated components, like input couplers and RF cables, were same as the TTF-III cryomodule. The other was designed by KEK, and the thermal design was based on the TTF-III cryomodule. This cryomodule contains four KEK cavities with the associated components which were designed by KEK. For characterizing the thermal performances of two cryomodules, the static heat load and the temperature profiles of the cold components were measured. The temperature profiles of the components were compared between two cryomodules and the static heat load was evaluated with the design values of the cryomodules. The dynamic losses of the DESY, FNAL and two KEK cavities at their maximum operative gradients were measured and, with the measured losses, Q values were calculated. In this paper, we will make the summary of the thermal measurements of the S1-Global cryomodule.

WEPS029

Innovative Superconducting Non Scaling Fixed Field Alternating Gradient Isocentric Gantry for Carbon Cancer Therapy*

focusing, ion, dipole, proton

2544

D. Trbojevic
BNL, Upton, Long Island, New York, USA
V.S. Morozov
JLAB, Newport News, Virginia, USA

Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.

WEPS047

Beamloss Study at J-PARC Linac by using Geant4 Simulation

beam-losses, simulation, scattering, linac

2595

T. Maruta
JAEA/J-PARC, Tokai-mura, Japan

Beamloss is one of the key issue for intense hadron beam accelerators. Most of case, origin of beamloss is scattering process between beam particle and residual gas inside vacuum duct. In the case of J-PARC Linac, H⁻ ions emitted from an Ion source are accelerated up to 181 MeV, then the beam is transported to RCS. The H⁻ ion is the system comprised from a proton and two electrons. If the H⁻ ion is scattered with residual gas, these one or two electrons are escaped, then H⁻ becomes H0 or H⁺(proton). H0 or H⁺ is uncontrollable and finally it goes to beam duct. This process is based on physics process, and Geant4 is matched to this kind of simulation study. I programmed SDTL (50 MeV) to L3BT (181 MeV) section at J-PARC Linac by using Geant4 code. I also wrote H⁻ and H0 library which makes it possible for Geant4 to simulate them. I will show the simulation results.

WEPZ005

Field Calculations to obtain Attosecond/Femtosecond Electron Bunches

cathode, laser, electron, injection

2772

V.A. Papadichev
LPI, Moscow, Russia

Obtaining short electron bunches of attosecond and femtosecond duration in a combined quasi-static and laser electric field [* - ****] requires careful field formation in the cathode region. First, the maximum of laser electric field normal to the cathode plate, depending on the incidence angle, was found employing Fresnel formulae using complex dielectric permittivity of metals. Second, laser field enhancement on cathode spikes was calculated for the case of an ellipsoid in a qusi-static approximation (laser wavelength larger than spike dimensions). Field enhancement is approximately proportional to the square of the ratio of major to minor axes of ellipsoid. Thus, enhancement factors as large as 100 - 1000 are obtainable, allowing to reduce laser power by 10 thousand to 1 million times.
* V.A.Papadichev, Patent RU 2 269 877 C1, 10.02.06, Bull. 4.
** V.A.Papadichev, Proc. EPAC08, p.2812.
*** V.A.Papadichev, Proc. EPAC08, p.2815.
**** V.A.Papadichev, Proc. IPAC'10, p. 4372

WEPZ006

Forming Attosecond Electron Pulses in Space-charge Dominated Regime

electron, laser, acceleration, bunching

2775

V.A. Papadichev
LPI, Moscow, Russia

Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [*, **, ***]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions.
* V.A.Papadichev, Proceedings of EPAC08, p.2815.
** V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372.
*** V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.

WEPZ012

Influence of Transition Radiation on Formation of a Bunch Wakefield in a Circular Waveguide

vacuum, wakefield, plasma, acceleration

2793

T.Yu. Alekhina, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: The Education Agency of Russian Federation.
Investigation of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration (WFA) technique and other problems in the accelerator physics. One of subjects of investigation in this area consists in analysis of transition radiation generated by the bunch flying into (out of) the dielectric structure. This radiation can be both destructive (for WFA) and useful (for diagnostics of bunch or material). We investigate the total field of small bunch crossing a boundary between two dielectrics in the waveguide. It includes a “forced” field and a “free” one. The “forced” field is the field of the charge in the unbounded waveguide (it can contain the wakefield). The “free” field is connected with influence of the boundary (it includes transition radiation). Two cases are analyzed in detail: the bunch flies from vacuum into dielectric and from dielectric into vacuum. The behavior of the field depending on distance and time is explored analytically and numerically. Some interesting physical effects are noted. As well, we make a comparison with the case of intersection between vacuum and cold plasma.

THOAB01

Accelerator-driven Subcritical Molten-salt-fueled Reactors

neutron, target, linac, proton

2868

R.P. Johnson
Muons, Inc, Batavia, USA
C. Bowman
ADNA, Los Alamos, New Mexico, USA

Reactors built using solid fissile materials sealed in fuel rods have an inherent safety problem in that volatile radioactive materials in the rods are accumulated and can be released in dangerous amounts. Accelerator parameters for subcritical reactors that have been considered in recent studies have primarily been based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium-burning accelerator-driven energy amplifier proposed by Rubbia et al. An attractive alternative reactor design that used molten salts was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels. These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work as well or better than conventional reactors, having better efficiency due to their higher operating temperature, having the inherent safety of subcritical operation, and having constant purging of volatile radioactive elements to eliminate their accumulation and potential accidental release in dangerous amounts.

Slides THOAB01 [5.723 MB]

THOAB02

Metal Nano-particle Synthesis by using Proton Beam

proton, electron, controls, cyclotron

2871

M.H. Jung, K. R. Kim, S.J. Ra
KAERI, Daejon, Republic of Korea

Funding: This work was conducted as a part of the Proton Engineering Frontier Project supported by the Ministry of Education Science & Technology of Korea Government.
Many scientists have studied metal nano-particles for newly known optical, electronic and chemical properties. The unique properties of nano-particles have a tendency to relate the particle size and shape. Electron beam have been used for the nano-particle synthesizing and many results were published. Study of nano-particles synthesize by using proton beam is still in the early stages however study for gold, silver, platinum and cobalt nano-particle was in progress. 100 MeV proton linear accelerator, which is by Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, is scheduled to be completed by 2012. Study of nano-particle synthesize by using proton beam will become active due to the completion of 100 MeV proton accelerator and it can be mass-produced because of the large current beam. Finally, industrial applications could become possible. The mechanism of metal nano-particles synthesizing by proton beam irradiation was not completely known. In this study, we investigated the changes of size and shape for metal nano-particle depending on the condition of proton beam irradiation, and concentration of additives by TEM and UV/Vis spectrophotometer.

Slides THOAB02 [9.791 MB]

THOBB03

Research and Development of Novel Advanced Materials for Next-generation Collimators

impedance, target, collimation, beam-losses

2888

A. Bertarelli, G. Arnau-Izquierdo, F. Carra, A. Dallocchio, M. Gil Costa, N. Mariani
CERN, Geneva, Switzerland

Funding: This work has partly been carried out through the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program.
The study of innovative collimators is essential to handle the high energy particle beams required to explore unknown territory in basic research. This calls for the development of novel advanced materials, as no existing metal-based or carbon-based material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by collimator extreme working conditions. A new family of materials, with promising features, has been identified: metal-diamond composites. These materials are to combine the outstanding thermal and physical properties of diamond with the electrical and mechanical properties of metals. The best candidates are Copper-Diamond (Cu-CD) and Molybdenum-Diamond (Mo-CD). In particular, Mo-CD may provide interesting properties as to mechanical strength, melting temperature, thermal shock resistance and, thanks to its balanced material density, energy absorption. The research program carried out on these materials at CERN and collaborating partners is presented, mainly focusing on the theoretical investigation, material characterization, and manufacturing processes.

Slides THOBB03 [3.948 MB]

THPC001

Progress Towards Implementation of Top-up at the Australian Synchrotron

injection, storage-ring, photon, 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.

THPC013

THz Studies at a Dedicated Beamline at the MLS

electron, synchrotron, synchrotron-radiation, storage-ring

2933

R. Müller, A. Hoehl, A. Serdyukov, G. Ulm
PTB, Berlin, Germany
J. Feikes, M. Ries, G. Wüstefeld
HZB, Berlin, Germany

The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin. The MLS is designed and prepared for a special machine optics mode (low-alpha operation mode) based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the THz region*. At the MLS two bending magnet beamlines dedicated to the use of IR and THz synchrotron radiation are in operation: the MLS-IR beamline optimized for the NIR to FIR, and a dedicated THz beamline optimized for the FIR/THz spectral range**. Low-alpha operation optic modes for different ring energies, 250 MeV, 350 MeV, 450 MeV and 630 MeV are available. We compare the THz spectra taken in the different low-alpha modes and discuss the results.
* J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
** R. Müller et al., J. Infrared Milli Terahz Waves, in press (2011), DOI: 10.10⁰⁷/s10762-011-9785-6.

THPC014

Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring

cavity, optics, focusing, electron

2936

G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries
HZB, Berlin, Germany

A scheme is discussed, where short and long bunches can be stored simultaneously in the BESSY II storage ring. With recent developments in sc-rf cavity technology it becomes possible, to install high gradient cavities in electron storage rings. With an appropriate choice of these cavities stable fixed points with different rf-voltage gradients are available, leading to different zero current bunch lengths. For BESSY II, we discuss the simultaneously storage of bunches with rms-lengths of 2 ps and 15 ps at high beam intensities. Additionally, in a low alpha optics sub-ps and ps-bunches are possible and a double bucket optics can be set up to store the two types of beams simultaneously on different orbits. Ultra-short and long bunches can be supplied to the users, separated by slightly different orbits.

THPC015

A Dedicated THz Beamline at DELTA

laser, electron, simulation, undulator

2939

M. Höner, M. Bakr, H. Huck, S. Khan, R. Molo, A. Nowaczyk, A. Schick, P. Ungelenk, M. Zeinalzadeh
DELTA, Dortmund, Germany

Funding: Work supported by DFG, BMBF, and by the Federal State NRW
As a consequence of the new radiation source for ultrashort VUV pulses at DELTA, which is based on the interaction of electrons with fs laser pulses, coherent THz radiation is emitted. Simulations of the laser-electron interaction, particle dynamics and radiation spectrum, as well as the optical and mechanical design of a dedicated THz beamline are presented. First experimental results including laser-electron overlap diagnostics and characterization of the THz radiation are discussed.

THPC016

Ultrashort VUV and THz Pulse Generation at the DELTA Storage Ring

laser, electron, undulator, klystron

2942

A. Schick, M. Bakr, H. Huck, M. Höner, S. Khan, R. Molo, A. Nowaczyk, P. Ungelenk, M. Zeinalzadeh
DELTA, Dortmund, Germany

Funding: Supported by DFG, BMBF, and the Federal State NRW
The optical klystron (two undulators, separated by a dispersive section) at DELTA, formerly operated as storage-ring FEL, is seeded with ultrashort pulses from a Ti:Sapphire laser. The thus induced energy modulation of an electron bunch in the first undulator is converted to a density modulation within the dispersive chicane. In the second undulator, the micro-bunched electrons emit ultrashort pulses coherently at harmonics of the fundamental laser wavelength. Additionally, coherent ultrashort THz pulses are generated several meters downstream of the optical klystron by the laser-induced gap in the electron bunch. First results are presented.

THPC021

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

diagnostics, cavity, storage-ring, photon

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.

THPC023

Third Generation Light Source Project in Iran

dipole, booster, emittance, lattice

2954

J. Rahighi, E. Salimi, R. safian
IPM, Tehran, Iran
M. Jafarzadeh, Kh.S. Sarhadi
ILSF, Tehran, Iran

The Institute for Research in Fundamental Sciences (IPM) is in charge of the establishing the Iranian Light Synchrotron Source Facility (ILSF). This facility will be a 3rd generation 3 GeV storage ring with a circumference of roughly 300 m. The injector will consist of a 150 MeV Linac and a full energy booster synchrotron. The storage ring has a four-fold symmetry with 4 long (7.88m), 16 medium (4.0 m) and 12 short (2.8 m) straight sections. Within the medium straight section there are mini beta values in order to get an optimized flux density for the users. The emittance is in the range of 3 nmrad. The booster synchrotron has a circumference of roughly 192 m with an emittance of roughly 31 nmrad. It is a separated function machine in order to have the maximum flexibility. For both machine it is foreseen to use a 500 MHZ RF-system with normal conducting cavities. The machine will be build in an international collaboration, in which the main components have to be supplied from international market. The conceptual design report should be finished in 2012, the commissioning of the machine is expected to be in 2020.

THPC027

Top-up Operational Experience at Elettra

storage-ring, injection, booster, controls

2966

E. Karantzoulis, A. Carniel, S. Krecic
ELETTRA, Basovizza, Italy

Since May 2010 Elettra, the third generation Italian light source, operates regularly for users at both 2 and 2.4 GeV in top-up. In this paper the experience during more than a year of operation in top-up at both user energies is discussed and the machine up time statistics presented and compared with the before top up period.

THPC040

Expected Performance Characteristic of Accelerator-based THz Source at Tohoku University

electron, undulator, focusing, gun

2990

H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka
Tohoku University, School of Science, Sendai, Japan
N.Y. Huang
NTHU, Hsinchu, Taiwan

Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003.
Sources of coherent synchrotron radiation at THz wavelength region have been constructed at Tohoku University. Bunch train of extremely shorter electron pulse less than 100 fs will be provided by an injector linac employing thermionic rf gun, where the bunch compression will be performed by means of velocity bunching in an accelerator structure. Radiation source under development are a Halbach type planar undulator and an accumulator isochronous ring. The undulator employs large gap and long period length configuration, so that the resonant frequency of 1 THz is achieved when a lower beam energy of ~ 20 MeV. Since spectrum of coherent synchrotron radiation (CSR) is strongly depending on longitudinal bunch form factor, we have calculated CSR spectra for various conditions of the beam to evaluate the performance of the THz source. Numerical simulation with multi-particle system has been carried out to understand the radiation power and angular distribution as well. The beam transport in the undulator is crucial for quality of the radiation because the beam energy is very much low relative to strong focusing power. Characteristics of THz CSR from the undulator will be discussed.

THPC041

Injector System of Test Accelerator as Coherent Terahertz Source

gun, cavity, electron, cathode

2993

S. Kashiwagi, H. Hama, F. Hinode, M. Kawai, X. Li, T. Muto, K. Nanbu, Y. Tanaka
Tohoku University, School of Science, Sendai, Japan
N.Y. Huang
NTHU, Hsinchu, Taiwan
F. Miyahara
KEK, Ibaraki, Japan

Funding: This work is supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (S), Contract #20226003.
A test accelerator as a coherent terahertz source (t-ACTS) project has been under development at Tohoku University, in which a generation of intense coherent terahertz (THz) radiation from sub-picosecond electron bunch will be demonstrated. We will supply a wide-band coherent radiation from bending magnets in an isochronous ring and a narrow-band coherent THz radiation using an undulator in a linac. Stable generation of very short electron bunch is one of the key issues in the t-ACTS project. The injector system is consists of a thermionic RF gun with two independent cavity cells, an alpha magnet and an accelerating structure. A velocity bunching scheme is employed to produce the very short electron bunch. Components of the t-ACTS injector except the accelerating structure have already been installed and we have started a high power RF processing of the gun cavities. The characteristics of electron bunch extracted from the RF gun are measured by varying phase and amplitude of input RF fields for the gun cavities. The status of t-ACTS project will be presented in the conference.

THPC052

Progress Towards Top-up Operation at SSRF

injection, storage-ring, controls, photon

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.

THPC053

Shanghai Soft X-Ray Free Electron Laser Test Facility

laser, linac, FEL, electron

3011

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

As a critical development step towards constructing a hard X-ray FEL in China, a soft X-ray FEL test facility (SXFEL) was proposed and will be constructed at the SSRF campus by a joint team of Institute of Tsinghua University and Shanghai Institute of Applied Physics. This test facility, based on an 840MeV electron linear accelerator, aims at generating 9nm FEL radiation with two-stage cascaded HGHG scheme. The project proposal was approved in February 2011 by central government, and the constrction is expected to start in early 2012. This paper describes the preliminary design of this soft X-ray test facility and the R&D progress of the key FEL technologies in the SDUV-FEL test bench.

THPC054

Project Status of the Polish Synchrotron Radiation Facility Solaris

storage-ring, linac, synchrotron, cavity

3014

C.J. Bocchetta, P.P. Goryl, K. Królas, M. Mlynarczyk, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak
Solaris, Krakow, Poland
J. Ahlbäck, Å. Andersson, M. Eriksson, M.A.G. Johansson, D. Kumbaro, S.C. Leemann, L. Malmgren, J.H. Modéer, P.F. Tavares, S. Thorin
MAX-lab, Lund, Sweden
E. Al-dmour, D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Funding: European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09
The Polish synchrotron radiation facility Solaris is being built at the Jagiellonian University in Krakow. The project is based on an identical copy of the 1.5 GeV storage ring being concurrently built for the MAX IV project in Lund, Sweden. A general description of the facility is given together with a status of activities. Unique features associated with Solaris are outlined, such as infra-structure, the injector and operational characteristics.

THPC055

Front Ends at ALBA

vacuum, photon, 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.

THPC068

CSR and THz Emission Measurements at the Diamond Light Source

electron, bunching, dipole, vacuum

3050

R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
I.P.S. Martin
JAI, Oxford, United Kingdom

After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

THPC071

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

dipole, vacuum, magnet-design, photon

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.

THPC076

FEL Performance with Focusing Lattice Magnets Alignment Errors

FEL, quadrupole, alignment, simulation

3071

V.G. Khachatryan, M. Ivanyan
CANDLE, Yerevan, Armenia

At the European XFEL the alignemnet errors of the undulator section quadrupole magnets will be corrected by applying beam based quadrupole alignment methods. Numerical simulations of the SASE process have been conducted to evaluate the FEL power reduction due to residual quadrupole alignment errors. FEL simulations with focusing lattice errors allow choosing an optimal error correction method in terms of FEL performance.

THPC081

Status of the Free-Electron Laser FLASH at DESY

FEL, undulator, photon, laser

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.

THPC082

Properties of the Radiation from the European X-ray Free Electron Laser

electron, FEL, undulator, emittance

3083

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

Recent success of the Linac Coherent Light Source (LCLS) demonstrated feasibility for reliable production, compression, and acceleration of electron beams with emittances significantly smaller than original baseline parameters. The same scenario can be applied to the European XFEL as well. Experimental results from the Photo Injector Test Facility in Zeuthen (PITZ) demonstrated the possibility to generate electron beams with small charge and emittance. Computer modeling of the beam formation system also indicate on the possibility to preserve electron beam quality during acceleration and compression. Recently these trends have been analyzed, and baseline parameters of the European XFEL have been revised. Parameter space has been significantly extended in terms of the bunch charge. As a result, different modes of FEL operation become possible with essentially different properties of the radiation. In this paper we present an overview of radiation properties of SASE FEL radiators driven by electron beam with new baseline parameters.

THPC083

Analysis of Parameter Space of a Kilowatt-scale Free Electron Laser for Extreme Ultraviolet Lithography Driven by L-band Superconducting Linear Accelerator Operating in a Burst Mode

electron, FEL, undulator, laser

3086

E. Schneidmiller, V. Vogel, H. Weise, M.V. Yurkov
DESY, Hamburg, Germany

The driving engine of the Free Electron Laser in Hamburg (FLASH) is an L-band superconducting accelerator. It is designed to operate in a burst mode with 800 microsecond pulse duration at a repetition rate of 10 Hz. The maximum accelerated beam current during the macropulse is 10 mA. In this paper we analyze the parameter space for optimum operation of the FEL at the wavelength of 13.5 nm and 6.7 nm. Our analysis shows that the FLASH technology holds great potential for increasing the average power of the linear accelerator and an increase of the conversion efficiency of the electron kinetic energy to the light. Thus, it will be possible to construct a FLASH like free electron laser with an average power up to 3 kW. Such a source meets the requirements of the light source for the next generation lithography.

THPC084

Optical Afterburner for a SASE FEL: First Results from FLASH

electron, FEL, undulator, resonance

3089

M. Foerst
CFEL, Hamburg, Germany
M. Gensch
HZDR, Dresden, Germany
R. Riedel, E. Schneidmiller, N. Stojanovic, F. Tavella, M.V. Yurkov
DESY, Hamburg, Germany

Radiation Pulse from a Self-Amplified Spontaneous Emission Free Electron Laser (SASE FEL) consists out of spikes (wavepackets). Energy loss in the electron beam (averaged over radiation wavelength) also exhibits spiky behaviour on a typical scale of coherence length, and follows the radiation pulse envelope. These modulations of the electron beam energy are converted into large density (current) modulations on the same temporal scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful optical radiation is then generated with the help of a dedicated radiator (afterburner). Envelope of the optical afterburner pulse is closely resembles the envelope of the x-ray pulse. We have recently demonstrated this principle at the Free Electron Laser in Hamburg (FLASH). We use THz undulator that is installed after the main X-ray as both dispersive element and radiator simultaneously. We characterize properties of the optical pulse using standard laser diagnostics techniques (i.e. FROG). Main result comes from the pulse duration measurement that we use to derive envelope of the x-ray radiation pulse duration which is in sub-100 fs range.

THPC089

Study of a Modified Quasi-periodic Undulator

undulator, photon, 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.

THPC100

Full Temporal Reconstruction using an Advanced Longitudinal Diagnostic at the SPARC FEL

FEL, diagnostics, undulator, laser

3119

G. Marcus, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
M. Artioli, F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
A. Bacci, M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, A. Mostacci, A.R. Rossi
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
INFN-Roma II, Roma, Italy
V. Petrillo
Istituto Nazionale di Fisica Nucleare, Milano, Italy
J.V. Rau
ISM-CNR, Rome, Italy

The Production of ultra-short (sub 100 fs) single-spike radiation possessing full longitudinal coherence from a free-electron laser (FEL) has been the subject of intense study. A Frequency-Resolved Optical Gating (FROG) diagnostic has been developed and tested at UCLA, which has the capability of providing a longitudinal reconstruction of these ultra-fast pulses. This paper reports the results of the application of the diagnostic at the SPARC FEL facility.

THPC102

Production of Coherent Optical \vCerenkov Radiation in Silica Aerogel

electron, scattering, photon, 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.

THPC108

Commissioning of the 50 MeV Preinjector Linac for the BESSY II Facility

linac, booster, emittance, injection

3140

T. Atkinson, M. Helmecke, D. Schüler, E. Weihreter
HZB, Berlin, Germany
V. Dürr
BESSY GmbH, Berlin, Germany
D. Jousse, J.-L. Pastre, A.S. Setty
THALES, Colombes, France

A turn key 50MeV linac manufactured by Thales has been installed in the BESSY II facility. This linac will replace the existing Microtron injector in the near future to provide more flexible bunch population patterns for the femto-slicing operation mode and a higher single bunch intensity for top-up injection. This paper describes the essential problems which have been faced during commissioning and presents the main results obtained in the site acceptance tests including the measurement of beam emittance and energy spread.

THPC118

Present Status of Quantum Radiation Sources on the Basis of the S-band Compact Electron Linac

laser, electron, cavity, linac

3164

R. Kuroda, E. Miura, H. Toyokawa, K. Yamada, E. Yamaguchi
AIST, Tsukuba, Ibaraki, Japan
M. Kumaki
RISE, Tokyo, Japan

We have developed quantum radiation sources such as a laser Compton scattering (LCS) X-ray and a coherent THz radiation sources on the basis of the S-band compact electron linac at AIST in Japan. The S-band linac consists of the laser-driven photocathode rf gun and two 1.5 m-long acceleration tubes and can accelerate the electron beam up to about 42 MeV. The LCS X-ray source can generate a quasi-monochromatic hard X-ray with variable energy of 12 - 40 keV for medical and biological applications. Now, the multi-collision LCS system has been developed with the regenerative amplifier type laser storage cavity and the multi-bunch electron beam to increase the X-ray yield. On the other hand, the high-power coherent THz radiation source has been also developed and its peak power is estimated to be more than 1 kW in frequency range between 0.1 - 2 THz. The high-power THz radiation was applied to the scanning transmission imaging. Now, the high power THz time domain spectroscopy (TDS) has been developed for the material science. In this conference, we will report the present status of the S-band compact electron linac, our quantum radiation sources and applications.

THPC146

The Radiated EMI Isolation for TPS Kicker Magnet*

shielding, kicker, electromagnetic-fields, controls

3227

C.S. Chen, C.K. Chan, C.L. Chen, Y.L. Chu, K.H. Hsu, C.Y. Kuo, Y.-H. Liu, C.-S. Yang
NSRRC, Hsinchu, Taiwan

Electromagnetic interference is a critical problem for electronic equipment, especially for those sophisticated measuring sensors using in TLS. Therefore, lots of efforts have been made to isolate the EM noise from the kicker magnets. In this article, different thicknesses of aluminum chambers are applied to block the radiated EM noise. Furthermore, the different widths of slits simulate the necessary openings on kicker assembly. According to the results of small-scale experiment, some parameters are obtained to design the enclosure of kicker magnet. Compared the results with the data from the original scale kicker, these parameters provide a believable guideline in the beginning of design status.

THPC164

Phase Shifters for the FERMI@Elettra Undulators

undulator, electron, FEL, polarization

3278

B. Diviacco, R. Bracco, D. Millo, M.M. Musardo
ELETTRA, Basovizza, Italy

The variable gap undulator system in operation at the FERMI@Elettra Free Electron Laser facility requires adjustable phase matching devices between consecutive radiator segments in order to maintain optimal lasing conditions while changing the radiation properties. A permanent magnet phase shifter has been designed to achieve the required electron beam delay in a compact structure that could be installed in close proximity to the undulators. In this paper we present the design of the phasing units and the results of the magnetic measurements performed on the five devices installed so far. We also describe the method used to properly set their field strength for any given electron energy, radiation wavelength and polarization.

THPC165

Estimations for Demagnetization of ID Permanent Magnets due to Installation of OTR

electron, permanent-magnet, simulation, undulator

3281

Y. Asano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Bizen
JASRI/SPring-8, Hyogo, Japan

Demagnetization due to high energy electron irradiation is one of the crucial issues for stable operation of X-ray free electron laser (XFEL) and Synchrotron radiation (SR) facilities. Especially, during the commissioning, electron beam is scattered and then hits permanent magnets of insertion devices due to installation of some instrumentations such as OTR (Optical Transition Radiation) for beam diagnosis so that the estimation of demagnetization is very important to perform the commissioning smoothly. Fortunately, we found the index of demagnetization of Nd2Fe14B permanent magnets due to high energy electron irradiation. Star density produced by high energy photo-neutron reproduces experimental results of demagnetization. At SPring-8, in-vacuum type undulators have been employed for XFEL so that we estimate the demagnetization of the undulators for various cases such as electron energy in ranging from 2 GeV to 8 GeV and the permanent magnet gap from 2 mm to 40 mm. And we also estimate the allowable time to be able to insert the OTR.

THPC166

Design Consideration of New Insertion Devices of Hefei Light Source

undulator, vacuum, photon, 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.

THPC167

The Design of Dual Canted In-vacuum Undulators at SSRF

undulator, vacuum, ion, synchrotron

3287

X. Hu, L. Yin, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

Funding: National foundation for scientific infrastructure, Development and Reform Commission of China.
Five new beamlines are under design and construction at SSRF to supply the synchrotron radiation for the structural biology research in the protein project. Two in-vacuum undulators with canted angle of 6mrad are arranged in a 6.5m long straight section in order to keep the potential to accommodate more beamlines for the future. Limited by the length of the straight section and the angle between two beamlines, the layout design in the straight section is rather difficult to satisfy the required photon flux to the beamline and keep the normal design of the undulator. Many main components will be redesigned in this section on the base of existing ones, including in-vacuum undulator, correction magnet, RF bellows, photon absorbers and so on. In this paper the layout design and the modified design for some key components are described.

THPC168

Field Error Correction for a Superconducting Undulator

undulator, photon, 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.

THPC169

Short-Period RF Undulator for a Nanometer SASE Source

undulator, electron, cavity, injection

3293

S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev
IAP/RAS, Nizhny Novgorod, Russia
J.L. Hirshfield
Yale University, Physics Department, New Haven, CT, USA
T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, Connecticut, USA

Funding: Sponsored in part by US Department of Energy, Office of High Energy Physics.
A room-temperature RF undulator to produce ~1 nm wavelength radiation using a relatively low energy electron beam (0.5 GeV) is considered. The design features include an effective undulator period of 0.45 cm, an undulator parameter of K = 0.4, an effective field length of 50 cm. These parameters could be be realized using a multi-MW RF power amplifier to drive the undulator (e.g., the 34 GHz pulsed magnicon at Yale or a 30 GHz gyroklystron at IAP) with microsecond pulse duration. Two undulator designs were considered that avoid problems with a co-propagating wave: a dual-mode cylindrical cavity [TE01 (counter propagating) - TE02 (co-propagating)] with an off-axis electron beam; and a traveling HE11 mode resonant ring with an on-axis beam.

THPC172

Superconducting 119-pole Wiggler for ALBA Light Source

wiggler, vacuum, electron, site

3302

N.A. Mezentsev, S.V. Khrushchev, V.K. Lev, E.G. Miginsky, V.A. Shkaruba, V.M. Syrovatin, V.M. Tsukanov, A.A. Volkov
BINP SB RAS, Novosibirsk, Russia
J. Campmany, D. Einfeld
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Budker INP of Siberian Branch of the Russian Academy of Science has designed, manufactured and tested 119-pole superconducting wiggler for ALBA CELLS light source. The period length and maximal field of the wiggler are 30 mm 2.2 Ò correspondingly. Pole gap and vertical aperture for electron beam are 12.6 mm and 8.5 mm, accordingly. The wiggler magnetic structure closely comes nearer to undulator structure as K-value is about 6. The wiggler cryostat is bath cryostat type with use of cryocoolers which provide zero liquid helium consumption for long period. In June, 2010 the wiggler has been successfully tested on ALBA site. Test results of the wiggler including magnetic measurement, quench training, cryogenic system behavior for various mode of operation are presented.

THPC178

Superconducting Planar Undulator Development in the UK

undulator, cryogenics, cryomodule, vacuum

3320

J.A. Clarke, D.J. Scott, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
V. Bayliss, T.W. Bradshaw, A.J. Brummitt, G.W. Burton, M.J.D. Courthold, M.J. Hills, S.R. Watson, M.L. Woodward
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

Superconducting undulators promise higher peak fields on axis than any other technology but they are still not a mainstream solution for 3rd or 4th generation light sources. A team within the UK is developing the design of a short period, narrow aperture, superconducting undulator that is planned to be installed and tested in the Diamond Light Source (DLS) in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. Recent progress is then described in the areas of magnet modelling, mechanical design, cryogenic design, and prototyping. Finally, the next steps are described.

THPC186

Heat Load for the APS Superconducting Undulator

photon, 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.

THPO022

Risk Assessment of the Chopper Dipole Kicker Magnets for the MedAustron Facility

dipole, controls, power-supply, kicker

3388

T. Kramer, T. Stadlbauer
EBG MedAustron, Wr. Neustadt, Austria
M.J. Barnes, M. Benedikt, T. Fowler
CERN, Geneva, Switzerland

The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and ions for both cancer therapy and research. Different types of kicker magnets will be used in the facility, including fast beam chopper dipoles: these allow the beam to be switched on and off for routine operational reasons or in case of emergency. One of the main requirements for the beam chopper system is reliability. A criticality analysis, to chart the probability of failure modes against the severity of their consequences of the fault, has been carried out for the chopper dipole system. This “Failure Mode, Effects, and Criticality Analysis” (FMECA), has been used to highlight failure modes with relatively high probability and severity of consequences: conservative ratings of critical components and appropriate redundancy, together with measurements and interlocks, have been used to reduce the probability and criticality of faults. This paper presents the results of the FMECA.

THPO025

Longitudinal Beam Dynamics of a Laser Sliced Bunch

laser, synchrotron, electron, damping

3397

P. Kuske
HZB, Berlin, Germany

Nowadays fs-laser slicing of a bunch of electrons in storage rings is quite common for creating short VUV- and soft X-ray light pulses or pulses of coherently emitted THz-radiation over a couple of revolutions. In this paper the longitudinal dynamics of the sliced bunch is studied numerically. The calculations are based on the one dimensional solution of the Vlasov-Fokker-Planck-equation assuming that the shielded CSR-wake is dominating the dynamics of the 100 fs-long slice. It is found that the density modulation survives longer and that the CSR-spectra extend to higher frequencies at later turns even below the corresponding instability threshold. This very simple model seems to support experimental observations at the Swiss Light Source.

THPS035

Collimator Upgrade Plan of the J-PARC Main Ring

injection, collimation, beam-losses, septum

3496

M.J. Shirakata, K. Ishii, C. Kubota, T. Oogoe, J. Takano
KEK, Ibaraki, Japan
Y. Kuniyasu
MELCO SC, Tsukuba, Japan
Y. Takiyama
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

A halo collimation system is prepared in the middle of injection-straight section in order to localize the beam loss occurred in main ring. It consists of three collimator units. The first unit scatters halo components, and the other two units work as halo catchers. The permitted amount of beam losses in the collimator section is designed to be 450 W at the present. The upgrade plan of halo collimation system is running in order to achieve about ten times larger beam loss capability for high-power beam operation. The collimator upgrade is planned by installing a new collimator set and radiation shields which cover the collimator section. New collimator units are designed to be able to line-out the jaw with a part of radiation shield including the mechanical devices. The design work of collimator units and radiation shields is presented in this report.

THPS062

Cavity-recirculated Laser Charge Stripping of Hydrogen Ions

neutron, cavity, laser, ion

3568

I. Jovanovic
Penn State University, University Park, Pennsylvania, USA
R. Tikhoplav
RadiaBeam, Santa Monica, USA

Funding: This work is supported by the U.S. Department of Energy.
High-intensity proton accelerators such as those at the Oak Ridge National Laboratory’s Spallation Neutron Source require an intense, robust, reliable, and low-cost source of hydrogen ions. Laser-based charge stripping is a promising, high-efficiency method that could meet the requirements of present and future facilities. We are seeking to improve the efficiency of hydrogen ion stripping by an order of magnitude using laser recirculation. In our approach we recirculate a high-power laser using the technique termed recirculation injection by nonlinear gating, with a frequency-doubling nonlinear crystal as an efficient switch that allow pulse injection into the cavity. We present our progress on cavity development and the preliminary experimental assessment of cavity performance in high-radiation environment. Our experimental studies were conducted by irradiating the nonlinear crystal used in the laser cavity by fast neutrons in a research nuclear reactor and measuring its change in transmissivity.

THPS068

A Proton Therapy Test Facility: The Radiation Protection Design

proton, shielding, neutron, simulation

3583

S. Sandri, M.C. Carpanese, G. Ottaviano, L. Picardi, C. Poggi, C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

A proton therapy test facility is planned to be sited in the Frascati ENEA Research Center, in Italy. A 30 m long, 3 m wide bunker has to be designed to host a proton linear accelerator with a low beam current, lower than 10 nA in average, and an energy up to 150 MeV. The accelerator will be part of the TOP-IMPLART project for deep tumors treatment. The design of the 150 MeV accelerator is under study and the radiation protection solutions are considered in this phase. The linear accelerator has some safety advantages if compared to cyclotrons and synchrotrons. It can be easily housed in the long, narrow tunnel. The main radiation losses during the acceleration process occur below 20 MeV, with a low neutron production. As a consequence the barriers needed should be substantially lighter than the one used for other types of machines. In the paper the simulation models and the calculation performed with Monte Carlo codes are described. The related results are presented together with those assessed by using published experimental data. Considerations about workers and population protection are issued in the conclusions.

THPS080

The New Bern Cyclotron Laboratory for Radioisotope Production and Research

cyclotron, target, proton, extraction

3618

S. Braccini, A. Ereditato
LHEP, Bern, Switzerland
P. Scampoli
Naples University Federico II, Napoli, Italy
K. von Bremen
SWAN, Bern, Switzerland

A new cyclotron laboratory for radioisotope production and multi-disciplinary research is under construction in Bern and will be operational by the end of 2011. A commercial IBA 18 MeV proton cyclotron, equipped with a specifically conceived 6 m long external beam line, ending in a separate bunker, will provide beams for routine 18-F production as well as for novel detector, radiation biophysics, radioprotection, radiochemistry and radiopharmacy developments. The accelerator is embedded into a complex building which hosts two physics laboratories, four GMP radiochemistry and radiopharmacy laboratories, offices and two floors for patient treatment and clinical research activities. This project is the result of a successful collaboration among the University Hospital in Bern (Inselspital), the University of Bern and private investors, aiming at the constitution of a combined medical and research center able to provide the most cutting-edge technologies in medical imaging and cancer radiation therapy. For this purpose, the establishment of a proton therapy center on the campus of Inselspital is in the phase of advanced study.

THPS084

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

target, electron, simulation, photon

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.

THPS090

Development of the Pulse Radiolysis System with a Supercontinuum Radiation using Photonic Crystal Fiber

laser, electron, gun, optics

3645

K.B. Ogata, R. Betto, Y. Hosaka, Y. Kawauchi, K. Sakaue, T. Suzuki, M. Washio
RISE, Tokyo, Japan
S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
R. Kuroda
AIST, Tsukuba, Ibaraki, Japan

Funding: Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690
In usage of radiation, it is important to study the process of chemical effects of ionizing radiation in a material. Pulse radiolysis is a method to trace these rapid initial chemical reactions by ionizing radiation. As a pump beam, we are using 5MeV electron beam produced from the S-band photo cathode RF-Gun. In nanosecond timescale pulse radiolysis, it is required the stable probe light of a broad spectrum. And especially in picosecond timescale pulse radiolysis, probe light should have short pulse width to use stroboscopic method. Therefore, in order to develop a wide range of timescale experimental system, we have been developing a Supercontinuum (SC) light as a probe light, which is generated by nonlinear optical process of short pulse IR laser in photonic crystal fiber (PCF). As a result, the SC light spectrum is broad enough to use as a probe light. Then we tried to measure the absorption spectrum of hydrated electron by SC light, we successfully observed good signal-noise ratio data both nanosecond and picosecond experiment with unified pulse　radiolysis system. In this conference, we will report details of these results and future prospects.

THPS091

Scientific Feasibility of Fusion Material Irradiation Experiments in ESS-B

proton, target, neutron, remote-handling

3648

I. Garcia-Cortes, A. Ibarra, R. Vila
CIEMAT, Madrid, Spain
E. Abad, R. Martinez
ESS Bilbao, Bilbao, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain

Material irradiation by protons is capable of simulating the effects of fusion neutrons (14 MeV, target damaging and He & H production) with a reasonably fast dose rate, according to theoretical calculations and previous experiments. Therefore, given that the ESS-Bilbao (ESS-B) accelerator, under construction in Bilbao, will provide an intense source of 50 MeV protons, with total currents of a few mA’s, a laboratory for fusion material testing is proposed. This paper appraises the scientific feasibility of performing fusion relevant experiments in the proposed laboratory. Material characterization under proton irradiation (by in-beam techniques to assess mechanical properties) while monitoring mechanical, micro-structural and compositional changes of the irradiated materials are some of the laboratory goals. Special emphasis is placed on expected radiation damage parameters in structural and functional materials, the beam power deposition in the sample and the consequences of material activation for the laboratory design.

THPS092

Conceptual Design of the ESS-Bilbao Materials Irradiation Laboratory

proton, neutron, target, simulation

3651

R. Martinez, E. Abad
ESS Bilbao, Bilbao, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
I. Garcia-Cortes, A. Ibarra, R. Vila
CIEMAT, Madrid, Spain

Funding: ESS-Bilbao
The baseline design for the first stage of the ESS-Bilbao proton linear accelerator up to 50 MeV is almost concluded and the linac is at present under construction. Three main application laboratories have been envisaged in this first stage: two proton irradiation laboratories and a low intensity neutron source. In particular, the high intensity proton beam of 50 MeV will be used to test structural materials for fusion reactors* under project named “Protons for Materials” (P4M), described in this contribution. The P4M irradiation room will be an underground facility located at the accelerator's tunnel depth. High levels of activation are expected in this irradiation room and its design presents challenges in both remote handling and independent operation from the other two surface laboratories. Thermal analysis of the beam power deposition over the target will be presented.
K. Konashyetal, Sci. Rep. RITU, A45(1997), pp.111-114.

THPS095

Q-factor of an Open Resonator for a Compact Soft X-ray Source based on Thomson Scattering of Stimulated Coherent Diffraction Radiation

cavity, electron, vacuum, scattering

3657

A.S. Aryshev, S. Araki, M.K. Fukuda, J. Urakawa
KEK, Ibaraki, Japan
V. Karataev
JAI, Egham, Surrey, United Kingdom
G.A. Naumenko
Tomsk Polytechnic University, Nuclear Physics Institute, Tomsk, Russia
A. Potylitsyn, L.G. Sukhikh, D. Verigin
TPU, Tomsk, Russia
K. Sakaue
RISE, Tokyo, Japan

High-brightness and reliable sources in the VUV and the soft X-ray region may be used for numerous applications in such areas as medicine, biology, biochemistry, material science, etc. We have proposed a new approach to produce the intense beams of X-rays in the range of eV based on Thomson scattering of Coherent Diffraction Radiation (CDR) on a 43 MeV electron beam. CDR is generated when a charged particle moves in the vicinity of an obstacle. The radiation is coherent when its wavelength is comparable to or longer than the bunch length. The CDR waves are generated in an opened resonator formed by two mirrors. In this report the status of the experiment, the first CDR measurements at the multibunch beam of the LUCX facility and general hardware design will be reported.

THPS096

Neutron-physical Characteristics of the Subcritical Setup with Natural Uranium Blanket Bombarded by 4 GeV Deuterons

neutron, target, proton, background

3660

M. Artiushenko, Y.T. Petrusenko, V.V. Sotnikov, V.A. Voronko
NSC/KIPT, Kharkov, Ukraine
A.A. Patapenka, A.A. Safronava, I.V. Zhuk
JIPNR-Sosny NASB, Minsk, Belarus

An extended U/Pb-assembly was irradiated with an extracted beam of 4 GeV deuterons from the Nuclotron accelerator at the JINR, Dubna, Russia. Information on the spatial distributions of neutrons in the lead target and the uranium blanket was obtained with sets of activation detectors (natPb and natU) and solid state nuclear track detectors (SSNTD). Spatial distribution of the natPb, and natU fission reaction rates in the volume of the target and blanket installation were obtained using SSNTD techniques. Activation method was used to obtain the spatial distributions of 238U(n,g), 238U(n,f) reactions rates. The procedure of combining the track counting and gamma-spectrometry techniques for the determination of spectral indices is a new development. It includes gathering information from the same sample by SSNTD methods, i.e., counting the fission tracks of 238U, and also by gamma-spectrometry of 239Np production. Sets of spectral indices values (ratio of 238U(n,g) to 238U(n,f) reaction rates), representing the integral nuclear data were defined. Comparison between the experimental data and the calculations performed with the use of the computer numerical code FLUKA2008 was made.

THPS101

Present and Perspectives of the Sparc THz Source

electron, linac, polarization, single-bunch

3669

E. Chiadroni, M. Bellaveglia, M. Boscolo, M. Castellano, G. Di Pirro, M. Ferrario, G. Gatti, E. Pace, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
P. Calvani, S. Lupi, A. Nucara
Università di Roma I La Sapienza, Roma, Italy
L. Catani, B. Marchetti
INFN-Roma II, Roma, Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
O. Limaj
University of Rome La Sapienza, Rome, Italy
A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

The development of radiation sources in the THz spectral region has become more and more interesting because of the peculiar characteristics of this radiation: it is non ionizing, it penetrates dielectrics, it is highly absorbed by polar liquids, highly reflected by metals and reveals specific "fingerprint" absorption spectra arising from fundamentals physical processes. The THz source at SPARC is an accelerator based source for research investigations (e.g. material science, biology fields). Its measured peak power is of the order of 10⁸ W, very competitive with respect to other present sources. The present status of the source is presented and future perspectives are presented.

THPS102

Novel Schemes for the Narrow Band Sparc THz Source using a Comb like e-beam

linac, cavity, electron, laser

3672

B. Marchetti
INFN-Roma II, Roma, Italy
M. Boscolo, M. Castellano, E. Chiadroni, M. Ferrario, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

The development of radiation sources in the THz spectral region has become more and more interesting because of the peculiar characteristics of this radiation: it is non ionizing, it penetrates dielectrics, it is highly absorbed by polar liquids, highly reflected by metals and reveals specific "fingerprint" absorption spectra arising from fundamentals physical processes. The THz source at SPARC is an accelerator based source for research investigations (e.g. material science, biology fields). By means of e-beam manipulation technique, a longitudinal modulated beam, the so-called comb beam, can be produced at Sparc. In terms of THz sources, such e-beam distribution allows to produce high intensitiy narrow band THz radiation, whose spectrum strongly depends on the charge distribution inside the e-beam. Different linac schemes are compared. In particular, spectra obtained using the comb-beam compression through velocity bunching including a IV harmonic RF section is showed.

THPS103

The Proton Engineering Frontier Project: Status and Prospect of Proton Beam Utilization

proton, linac, target, DTL

3675

K. R. Kim, Y.-S. Cho, B.H. Choi, J-Y. Kim, K.Y. Kim, J. W. Park
KAERI, Daejon, Republic of Korea

Funding: This work has been supported by the Ministry of Education, Science, and Technology, Republic of Korea.
A 100-MeV, 20-mA high intensity proton linac is to be constructed in 2012 by the PEFP (Proton Engineering Frontier Project) of the Korea Atomic Energy Research Institute, which was started in 2002 with three main objectives; development of high intensity proton linac, development of proton beam utilization technologies, and industrialization of developed technologies. Proton beams with variable energy and current can be provided to the users from various research and application fields such as nano-, bio-, semiconductor-, space-, radiation-, environment-technologies and medical- and basic sciences, etc. through 10 targets rooms, which are assigned specific application fields to meet various user’s beam requirements. Following a brief introduction to the accelerator development, multiple beamline development and the construction works, we will review the achievements of our user program which have been operated over the past 8 years to cultivate and foster proton beam users and beam utilization technologies in diverse R&D fields. In addition, we will discuss the perspectives of the beam utilization in conjunction with design and construction of user facilities.

THPS104

Radio-activation Effect of Target Rooms for PEFP's 20~100 MeV Linear Accelerator

proton, target, neutron, simulation

3678

S.J. Ra, M.H. Jung, K. R. Kim
KAERI, Daejon, Republic of Korea

Funding: This work was conducted as a part of the Proton Engineering Frontier Project supported by the Ministry of Education Science & Technology of Korea Government.
PEFP (Proton Engineering Frontier Project) has developed a 20~100 MeV/20 mA proton linear accelerator, proton beam utilization technology and accelerator applications, in order to acquire core technologies which are essential to develop future science and secure the industrial competitiveness. In the experimental hall, 10 target rooms will be constructed for the research of radioisotopes, material, medical, neutron source, etc. In the irradiation experiments using proton beam of more than a few MeV energy, radio-activation of targets and equipments can be essentially caused by the proton induced nuclear reactions. Highly radioactive samples occasionally makesome problems or inconveniences concerning with sample handling and post-treatment because we have to wait for the samples to be cooled down under the safe value for radiation protection. So we estimated proton beam irradiation condition of each target room and used samples including equipments, then we calculated radio-activation of each target room by using Monte Carlo N-particle Transport Code.

THPZ010

Beam Background and MDI Design for SuperKEKB/Belle-II

background, luminosity, scattering, positron

3702

H. Nakayama, M. Iwasaki, K. Kanazawa, Y. Ohnishi, S. Tanaka, T. Tsuboyama
KEK, Tsukuba, Japan
H. Nakano
Tohoku University, Graduate School of Science, Sendai, Japan

The Belle experiment, operated at the asymmetric electron-positron collider KEKB, had accumulated a data sample with an integrated luminosity of more than 1 at^-1before the shutdown in June 2010. We have started upgrading both the accelerator and detector, SuperKEKB and Belle-II, to achieve the target luminosity of 8x10³5 cm^-2s^-1. With the increased luminosity, the beam background will also increase. The development of Machine-Detector Interface (MDI) design is very important to cope with the increased background and protect Belle-II detector. We will present the estimation of impact from each beam background sources at SuperKEKB and our countermeasures for them, such as collimators to stop Touschek-scattered beam particles, Tungsten shield to protect inner detectors from shower particles, dedicated beam pipe design around interaction point to stop synchrotron radiation, etc.

THPZ015

Synchrotron Radiation in the Interaction Region for a Ring-Ring and Linac-Ring LHeC

linac, interaction-region, electron, luminosity

3717

N.R. Bernard
UCLA, Los Angeles, California, USA
R. Appleby, L.N.S. Thompson
UMAN, Manchester, United Kingdom
N.R. Bernard
ETH, Zurich, Switzerland
B.J. Holzer, R. Tomás, F. Zimmermann
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom
P. Kostka
DESY Zeuthen, Zeuthen, Germany
B. Nagorny, U. Schneekloth
DESY, Hamburg, Germany

The Large Hadron electron Collider (LHeC) aims at bringing hadron-lepton collisions to CERN with center of mass energies in the TeV scale. The LHeC will utilize the existing LHC storage ring with the addition of a 60 GeV electron accelerator. The electron beam will be stored and accelerated in either a storage ring in the LHC tunnel (Ring-Ring) or a linac tangent to the LHC tunnel (Linac-Ring). Synchrotron Radiation (SR) in the Interaction Region (IR) of this machine requires an iterative design process in which luminosity is optimized while the SR is minimized. This process also requires attention to be given to the detector as the beam pipe must be designed such that damaging effects, such as out-gasing, are minimized while the tracking remains close to the IP. The machinery of GEANT4 has been used to simulate the SR load in the IR and also to design absorbers/masks to shield SR from backscattering into the detector or propagating with the electron beam. The outcome of these simulations, as well as cross checks, are described in the accompanying poster which characterizes the current status of the IR design for both the Ring-Ring and Linac-Ring options of the LHeC in terms of SR.

THPZ031

Acoustic Measurements in the Collimation Region of the LHC

background, collimation, beam-losses, proton

3759

D. Deboy, R.W. Assmann, C. Baccigalupi, F. Burkart, M. Cauchi, C.S. Derrez, J. Lendaro, A. Masi, S. Redaelli, G. Spiezia, D. Wollmann
CERN, Geneva, Switzerland

The LHC accelerator at CERN has the most advanced collimation system ever being installed. The collimators intercept unavoidable particle losses and therefore are essential to avoid beam induced quenches of the superconducting magnets. In addition, they provide passive machine protection against mis-kicked beams. During material robustness tests on a LHC collimator prototype in 2004 and 2006, vibration and acoustic measurements have shown that a beam impact detection system should be feasible using accelerometers and microphones as sensors in the LHC. Recently, such sensors have been installed close to the primary collimators in the LHC tunnel. First analyses of raw data show that the system is sensitive enough to detect beam scraping on collimators. Therefore, the implementation of a sophisticated acoustic monitoring system is under investigation. It may be useful not only to detect beam impacts on primary collimators in case of failure, but also to derive further information on beam losses that occur during regular operation. This paper gives an overview on the recent installation, results of the acoustic measurements made at the LHC, and future plans.