EPAC08 - List of Keywords (radiation)

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radiation

Paper	Title	Other Keywords	Page
MOYAGM01	Review of DESY FEL Activities	electron, undulator, laser, emittance	7
	J. Rossbach Uni HH, Hamburg J. Rossbach DESY, Hamburg
	A general overview will be given of DESY FEL activities. Overview of the technological upgrades and results of beam commissioning of the FLASH FEL. The talk will cover the latest results from FLASH at the shortest wavelengths. A description will be given of critical systems and performance. The status of the XFEL will be given, including integration of FLASH technology.
	Slides

MOZAG02	Short Bunches in Electron Storage Rings and Coherent Synchrotron Radiation	storage-ring, optics, electron, synchrotron	26
	G. Wuestefeld BESSY GmbH, Berlin
	Significant progress has been made in recent years in achieving short bunches in third generation synchrotron light sources and the generation of coherent radiation. This talk will review the properties of the radiation and the associated beam dynamics, and will discuss optics issues and the limits of the available techniques.
	Slides

MOZBG01	Vacuum Performances in the Most Recent Third Generation Synchrotron Light Sources	vacuum, storage-ring, synchrotron, impedance	31
	E. Al-Dmour ALBA, Bellaterra
	Several 3rd generation synchrotron light sources were built and commissioned during the last ten years. The vacuum system of these light sources was designed using different approaches, but with the same objectives which guarantee the lowest outgassing rate and the highest pumping speed that by the end will achieve the lowest influence in the circulated beam (longest life time, the lowest impedance and instabilities, etc). The performance of recently commissioned rings (DIAMOND, SOLEIL and the Australian Light Source) are presented, together with a comparison of the different approaches which have been used in the design of the vacuum system and the lessons for the design of new vacuum systems.
	Slides

MOPC002	Extension of the FERMI FEL1 to Shorter Wavelengths	electron, simulation, undulator, laser	64
	E. Allaria ELETTRA, Basovizza, Trieste G. De Ninno University of Nova Gorica, Nova Gorica
	We propose a modification of the first stage (FEL-1) of the FERMI@Elettra project in order to extend the wavelength from the original limit of 40 nm down to 20 nm. The modified setup takes advantage of a shorter radiator undulator period. We present the numerical studies that have been carried out to compare the expected performance of the new FEL-1 with that of the original FERMI setup. Results show that the modified configuration represents a good alternative to the second stage of the project (FEL-2) in the wavelength range between 40 nm and 20 nm. C. J. Bocchetta et al. 'FERMI@Elettra Conceptual Design Report' ST/F-TN-07/12 (2007)

MOPC005	The ARC-EN-CIEL Radiation Sources	undulator, electron, laser, brilliance	73
	M.-E. Couprie, M. Labat CEA, Gif-sur-Yvette C. Benabderrahmane, O. V. Chubar, G. Lambert, A. Loulergue, O. Marcouillé SOLEIL, Gif-sur-Yvette C. Bruni LAL, Orsay L. Giannessi ENEA C. R. Frascati, Frascati (Roma)
	The ARC-EN-CIEL project proposes a panoply of light sources for the scientific community on a 1 GeV superconducting LINAC (phase 2) on which two ERL loops (1 and 2 GeV) are added in phase 3. LEL1 (200-1.5 nm), LEL2 (10-0.5 nm) and LEL4 (2-0.2 nm) are three kHz High Gain Harmonic Generation Free Electron Laser sources seeded with the High order Harmonics generated in Gas, with 100-30 FWHM pulses. A collaboration, which has been set-up with the SCSS Prototype Accelerator in Japan for test this key concept of ARC-EN-CIEL, has led to the experimental demonstration of the seeding with HHG and the observation up the 7th non linear harmonic with a seed at 160 nm. Besides. LEL3 (40-8 nm) installed on the 1 GeV loop is a MHz FEL oscillator providing higher average power and brilliance. In addition, in vacuum undulator spontaneous emission source extend the spectral range above 10 keV and intense THz radiation is generated by edge radiation of bending magnets. Optimisations and light sources characteristics are described.

MOPC012	PSI XFEL Simulations with SIMPLEX and GENESIS	undulator, simulation, electron, emittance	91
	V. G. Khachatryan, V. M. Tsakanov CANDLE, Yerevan R. J. Bakker PSI, Villigen V. V. Sahakyan, A. Tarloyan YSU, Yerevan
	The numerical simulation results of the SASE FEL process for PSI XFEL project are presented. The main purpose of the investigations using FEL simulation codes SIMPLEX and GENESIS is the reliable definition of the undulators design parameters (K value, period, segment length, number of segments) that provide desirable radiation characteristics such as wavelength, bandwidth, saturation length, peak power and the brightness.

MOPC013	Effect of Jitter and Quadrupole Alignment Errors on SASE FEL Performance	quadrupole, undulator, electron, simulation	94
	V. G. Khachatryan, A. Tarloyan, V. M. Tsakanov CANDLE, Yerevan W. Decking DESY, Hamburg
	Numerical simulations of the radiation process at the European XFEL project are presented. The impact of quadrupole misalignments on the saturation length and saturation power is investigated using the simulation codes SIMPLEX and GENESIS. The influence of trajectory steering in the presence of BPM misalignments on the FEL performance is analyzed. The study is performed for the SASE 1 undulator designed for 0.1nm radiation wavelength.

MOPC014	Optimization of the Focusing Lattice for European XFEL	lattice, simulation, undulator, focusing	97
	V. G. Khachatryan, A. Tarloyan, V. M. Tsakanov CANDLE, Yerevan W. Decking DESY, Hamburg V. V. Sahakyan YSU, Yerevan
	Detailed knowledge of the impact of the undulator section focusing lattice on the FEL performance is an important issue to ensure the stable operation of the facility with reliable tolerances. In this paper the results of numerical simulation studies for the European XFEL project are presented. The saturation length, saturation power and the spectral brightness of the SASE FEL are calculated for various focusing lattice arrangements. A focusing optics option with reduced number of FODO cells is discussed to reach the design goals with relaxed quadrupole magnet tolerances. The numerical simulations are performed using the SIMPLEX and GENESIS codes.

MOPC017	Operation of the UVSOR-II CHG-FEL in Helical Configuration	laser, undulator, polarization, electron	106
	M. Labat CEA, Gif-sur-Yvette M.-E. Couprie, G. Khalili SOLEIL, Gif-sur-Yvette M. Hosaka, N. Yamamoto Nagoya University, Nagoya M. Katoh, M. Shimada UVSOR, Okazaki A. Mochihashi JASRI/SPring-8, Hyogo-ken
	In the Coherent Harmonic Generation Free Electron Laser (CHG-FEL) configuration, an external laser source injected inside a first undulator modulates in energy, and consequently in phase, an electron bunch, allowing coherent radiation in a second undulator. The CHG-FEL implemented on UVSOR-II storage ring (Okazaki, Japan) consists of a 600 MeV electron beam, and of a 2.5 mJ Ti:Sa seeding laser at 800 nm wavelength, 1 kHz repetition rate, and 100 fs up to 2 ps pulse duration. Operation in planar configuration of the undulators is being characterized since 2005. Recent experiments enabled a step forward using helical configuration of the undulators. A description of the experimental setup is given, and the main results are presented: influence of seeding laser parameters (polarisation, average power, focusing) on the intensity and beam profile of the second and third coherent harmonics. Those investigations provide attractive insights for the future HGHG FEL sources, about to deliver sub-nm and sub-ps pulses.

MOPC018	Seeding the FEL of the SCSS Test Accelerator with the 5th Harmonic of a Ti: Sa Laser Produced in Gases	undulator, laser, electron, injection	109
	G. Lambert, O. V. Chubar, M.-E. Couprie SOLEIL, Gif-sur-Yvette M. Bougeard, B. Carré, D. Garzella, O. B. Gobert, M. Labat, H. Merdji, P. Salieres CEA, Gif-sur-Yvette T. Hara, T. Ishikawa, H. Kitamura, T. Shintake, M. Yabashi RIKEN/SPring-8, Hyogo K. Tahara, Y. T. Tanaka, T. Tanikawa RIKEN Spring-8 Harima, Hyogo
	We present the strong amplification of the 5th harmonic of a Ti: Sa laser (10 Hz, 100 fs) generated in a Xe gas cell, i.e. 160 nm, and the generation of intense and coherent odd and even Non Linear Harmonics (NLH) from 80 nm to 23 nm. The experiment has been carried out on the SCSS (SPring-8 Compact SASE Source, Japan) Test Accelerator FEL. This facility is mainly based on a thermionic cathode electron gun, a C-band LINAC (5712 MHz, 35 MV/m) and an in-vacuum undulator (15 mm of period, 2 sections of 4.5 m length). The external source is properly focused in the first undulator section in order to efficiently interact with the electron beam (150 MeV, 10 Hz, 0.5-3 ps). In case of high peak current mode, the 160 nm seed light is amplified by a factor of 7000 in the first undulator section. Moreover, the amplification can be observed even for very low HHG seed level. This result opens new perspectives for seeding at short wavelengths in the XUV to soft X-Ray region. Association with NLH, HGHG (High Gain Harmonic Generation) and/or cascade schemes would allow the generation of fully coherent X-ray radiations from the “water window” spectral range to the Angstrom region.

MOPC026	Status of SPARX Project	undulator, electron, linac, laser	121
	L. Palumbo Rome University La Sapienza, Roma
	The SPARX project consists in an X-ray-FEL facility jointly supported by MIUR (Research Department of Italian Government), Regione Lazio, CNR, ENEA, INFN and Rome University Tor Vergata. It is the natural extension of the ongoing activities of the SPARC collaboration. The aim is the generation of electron beams characterized by ultra-high peak brightness at the energy of 1.2 and 2.4 GeV, for the first and the second phase respectively. The beam is expected to drive a single pass FEL experiment in the range of 13.5-6 nm and 6-1.5 nm, at 1.2 GeV and 2.4 GeV respectively, both in SASE and Seeded FEL configurations.

MOPC027	A Fast Switching Mirror Chamber for FLASH	feedback, laser, electron, controls	124
	S. Pauliuk, U. Gensch, R. Heller, M. Sachwitz, H. Thom, D. Thürmann DESY Zeuthen, Zeuthen U. Hahn, S. Karstensen, H. Schulte-Schrepping, K. I. Tiedtke DESY, Hamburg
	Switching mirrors are used to provide several beamlines with FEL or synchrotron radiation from one source. Since most users do not need the nominal pulse density, this is a method to supply many experimental groups. So far, the switching process has a duration of several minutes. A study at DESY Zeuthen analyzes the possibility and accuracy of permanent switching, e.g. at half the FEL's pulse frequency of 1 to 10 Hz. A prototype satisfying highest demands on repetition accuracy of the position (below 1 μm) and yawing (about 1 arcsec) is being tested. In the course of the work many technical concepts from industry like PLC or Position-Velocity Streaming found their way into beamline technology, allowing fast proceedings in development.

MOPC028	Experimental Layout of 30 nm High Harmonic Laser Seeding at FLASH	electron, undulator, laser, photon	127
	H. Schlarb, S. Düsterer, J. Feldhaus, T. Laarmann DESY, Hamburg A. Azima, J. Boedewadt, H. Delsim-Hashemi, M. Drescher, S. Khan, Th. Maltezopoulos, V. Miltchev, M. Mittenzwey, J. Rossbach, R. Tarkeshian, M. Wieland Uni HH, Hamburg
	Since 2004, the free-electron laser FLASH at DESY has operated in the Self-Amplified Stimulated Emission mode, delivering to users photon beams with wavelengths between 6.5 nm and 40 nm. In 2009, DESY plans to install a 3.9 GHz RF acceleration section for the production of electron bunches with high peak currents (~kA), but ten times larger pulse durations (~250 fs) compared to the present configuration. The relaxed timing requirements of the new configuration make it possible to externally seed FLASH with high harmonics of an optical laser (sFLASH). The aim of the project is to study the technical feasibility of seeding an FEL at 30 nm with a stability suited for user operation. sFLASH will use 10 m of gap-tunable undulators installed in front of the fixed gap SASE-undulator. A chicane behind the seeding undulators will allow to extract the output radiation for a careful characterisation and for first pump-probe experiments with a resolution in the 10 fs range by combining FEL and seed laser pulses.

MOPC029	Longitudinal Structure of Electron Bunches at the Micrometer Scale from Spectroscopy of Coherent Transition Radiation	electron, linac, collective-effects, space-charge	130
	B. Schmidt, C. Behrens, S. Wesch DESY, Hamburg H. Delsim-Hashemi, J. Rossbach, P. Schmüser Uni HH, Hamburg
	At the free electron laser FLASH in Hamburg, a longitudinal bunch compression scheme is used resulting in a longitudinal current profile with a narrow leading spike. Part of this spike is responsible for producing high-intensity short FEL pulses via the SASE process. The width and the structure of the current spike, which are key parameters for the efficiency of the SASE process, are barely accessible to direct measurements in the time domain. Using an infrared multi-stage grating spectrometer, we have studied the spectral composition of coherent transition radiation from single electron bunches. The data show that the 'fundamental width' of the current spike is about 40 fs (fwhm) with prominent substructures down to the 10 fs scale. The intensity fluctuations of coherent radiation in the corresponding wavelength range are strongly correlated to the fluctuations of the FEL pulse energy. Extension of the method to the near infrared regime have revealed micro-structures with characteristic lengths from a few micrometers down to fractions of a micrometer. Their interrelation with the parameters of the electron beam and the compression system have been studied.

MOPC030	Operation of FLASH at 6.5 nm Wavelength	laser, gun, electron, linac	133
	S. Schreiber, B. Faatz, K. Honkavaara DESY, Hamburg
	FLASH, the Free-Electron-Laser at DESY, Germany has been upgraded in 2007. A 6th accelerating module with eight 9-cell superconducting cavities of the TESLA type has been installed. In addition, another module has been replaced and the tuners of a third module have been repaired. In September 2007, a beam energy of 1 GeV has been achieved for the first time, followed by lasing at 6.5 nm shortly after. With this remarkable achievement, the initial design goals of the FEL in terms of beam energy and wavelength have been reached.

MOPC037	Single Spike Operation in SPARC SASE-FEL	emittance, undulator, injection, simulation	154
	V. Petrillo, I. Boscolo Universita' degli Studi di Milano, Milano A. Bacci, S. Cialdi, L. Serafini INFN-Milano, Milano R. Bonifacio, M. Boscolo, M. Ferrario, C. Vaccarezza INFN/LNF, Frascati (Roma) F. Castelli Università degli Studi di Milano, Milano L. Giannessi, C. Ronsivalle ENEA C. R. Frascati, Frascati (Roma) L. Palumbo Rome University La Sapienza, Roma S. Reiche, J. B. Rosenzweig UCLA, Los Angeles, California M. Serluca INFN-Roma, Roma
	We describe in this paper a possible experiment with the existing SPARC photoinjector to test the generation of sub-picosecond high brightness electron bunches able to produce single spike radiation pulses at 500 nm in the SPARC self-amplified spontaneous emission free-electron laser (SASE-FEL). The main purpose of the experiment will be the production of short electron bunches as long as few SASE cooperation lengths and to validate scaling laws to foresee operation at shorter wavelength in the future operation with SPARX. The basic physics, the experimental parameters and 3-D simulations are discussed. Complete start-to-end simulations with realistic SPARC parameters are presented, in view of an experiment for tests on superradiant theory with the existing hardware.

MOPC041	Microfabrication of Relativistic Electron Beam by Laser and its Application to THz Coherent Synchrotron Radiation	electron, laser, storage-ring, synchrotron	163
	M. Katoh, M. Adachi, S. I. Kimura, A. Mochihashi, M. Shimada UVSOR, Okazaki S. Bielawski, C. Evain, C. Szwaj PhLAM/CERCLA, Villeneuve d'Ascq Cedex T. Hara RIKEN Spring-8 Harima, Hyogo M. Hosaka, Y. Takashima, N. Yamamoto Nagoya University, Nagoya T. Takahashi KURRI, Osaka
	It is well known that broadband coherent synchrotron radiation (CSR) is emitted by an electron bunch whose length is shorter than radiation wavelength. However, even a long electron bunch can emit CSR when it has micro-density structure whose characteristic length is equal to the radiation wavelength. Recently, we have demonstrated that, by injecting amplitude modulated laser pulses into an electron storage ring, quasi-monochromatic and tunable terahertz (THz) CSR could be produced. In this method, periodic micro-density structure of THz scale was created on the electron bunch, as the result of the laser-electron interaction. The bunch emitted quasi-monochromatic THz radiation in a uniform dipole filed, not in an undulator. This new technology provides a way to imprint periodic wave patterns inside the electron bunch phase space. In adding to the light source applications, this would be a new tool to investigate electron beam dynamics.

MOPC048	Coherent Synchrotron Radiation Burst from Electron Storage Ring under External RF Modulation	synchrotron, synchrotron-radiation, electron, storage-ring	178
	Y. Shoji NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo T. Takahashi KURRI, Osaka
	It is known that a high-peak-current beam in an electron storage ring emits a burst of coherent synchrotron radiation (CSR) in the THz region. This CSR is powerful and easily obtained with no special expense, but is not used by synchrotron radiation users. This is because the burst arises from a fine time structure in the bunch due to longitudinal beam instabilities, and is unstable. We quantitatively investigated its time structure to find out how unstable it is. The measurements of CSR from one bunch showed that with an average period of 10ms (comparable with the damping time, 12 ms) the fluctuation of averaged power was about 10%. This would be reduced to 1% with 100 bunches. The fluctuation ratio had small dependence on beam charge, rf acceleration voltage and momentum compaction factor. The successive bursts had a correlation because the beam had a memory of former bursts. This worked to reduce the fluctuation in long period. When the rf phase was modulated with 2fs (twice of the synchrotron oscillation frequency), the burst structure was modulated with 2fs and the long term fluctuation was reduced. This modulation can be used to eliminate background noise in user experiments.

MOPC064	Beam Losses Due to Intra-Beam and Residual Gas Scattering for Cornell's Energy Recovery Linac	beam-losses, scattering, undulator, simulation	214
	A. Temnykh Cornell University, Department of Physics, Ithaca, New York M. P. Ehrlichman, G. Hoffstaetter CLASSE, Ithaca
	In this paper we analyze particle loss rates in Cornell's x-ray Energy Recovery Linac. Because of the small beam emittances and high beam intensity, intra-beam scattering (IBS) can be a source of significant particles loss in the horizontal plane. It will result in radiation doses which should be carefully examined for adequate radiation protection. Additionally, scattering on the residual gas (RGS) causes particle losses in the vertical plane. With Mote-Carlo type simulations of the scattering processes and transport matrixes for particle-trajectory propagation we found the beam loss distribution along ERL. It indicated that 99% of the total beam loss will be due to IBS. However, the RGS contribution can not be ignored because it dominates scattering in the vertical plane causing IDs irradiation and damage. For both (IBS and RGS) processes the highest beam losses will occur at the end of deacceleration due to adiabatic anti-damping causing traverse betatron amplitudes to increase. These beamlosses can be consentrated in collimation sections. Knowing RGS beam loss rates at the ID locations, we estimate the ID’s life time and suggest a radiation protection scheme.

MOPC085	High Power Neutron Converter for Low Energy Proton/Deuteron Beams: Liquid Metal Driving System	target, proton, vacuum, controls	256
	M. F. Blinov, V. A. Golikov, V. Gubin, M. A. Kholopov, P. V. Logachev, V. S. Popov, S. V. Shiyankov, I. E. Zhul BINP SB RAS, Novosibirsk
	Nowadays in BINP, Russia, the high-power high-temperature rotated graphite-made neutron converter is proposed in order to use neutron source for SPES (INFN-LNL, Italy) and SPIRAL-II (GANIL, France). The target is designed to produce up to 10¹⁴ neutron per second within the energy range of several MeV under irradiation by proton/deuteron beam of power up to 200 kW. One of main problem on the converter development is to provide the reliable and effective driving gear and cooling systems. The main elements of the system must be liquid metal pumps and motors, cooling channels and heat exchanger. This paper describes proposed scheme, its basic technical parameters, estimations of the system whole as well as of separate elements. The lead-tin alloy is used as the transmission agent. At present the prototype of liquid metal motor/pump is successfully manufactured and operates for more than 16000 h in continuous regime.

MOPC093	Experimental Study of Radiation Damage in Carbon Composites and Graphite Considered as Targets in the Neutrino Super Beam	proton, target, isotope-production, linac	280
	N. Simos, H. G. Kirk BNL, Upton, Long Island, New York K. T. McDonald PU, Princeton, New Jersey
	Carbon composites have been of primary interest as materials of choice for a multi-MW neutrino superbeam which desires low-Z pion production target. Beam on target experiments conducted at BNL made the case stronger in their favor, as compared to graphite, by demonstrating their excellent shock resistance which is directly linked with their extremely low thermal expansion. Since target survivability also depends on resistance to prolonged radiation, a series of irradiation damage studies on carbon composites and graphite were launched. While carbon composites at moderate doses exhibited interesting behavior of damage reversal through thermal annealing, at higher dose levels of peak proton fluences >5x10²⁰ protons/cm² they exhibited serious structural degradation. The experimental study also showed that graphite suffered similar damage when subjected to same fluence level. The paper discusses the findings of the experimental studies focusing on these materials and attempts to explain their structural degradation observed under high proton fluences given the excellent survivability record, especially of graphite, under high neutron fluences in nuclear reactor settings. Work performed under the auspices of the US DOE.

MOPC094	Irradiation Effects on the Physio-mechanical Properties of Super-alloys Characterized by Low Thermal Expansion	proton, target, photon, electron	283
	N. Simos, H. G. Kirk BNL, Upton, Long Island, New York K. T. McDonald PU, Princeton, New Jersey N. V. Mokhov Fermilab, Batavia, Illinois
	In an effort to address the limitations on high power accelerator target performance prompted by the elevated dose levels and the associated irradiation damage, an experimental study has been undertaken to evaluate the potential applicability of super alloys characterized by low thermal expansion over certain thermal regimes. The intriguing properties associated with materials such as super-Invar and the “gum” metal (Ti-12Ta-9Nb-3V-6Zr-O) are observed in their un-irradiated state. Irradiations were performed using the 200 MeV protons of the BNL Linac and/or a neutron flux generated by the stopping of the primary 112 MeV protons upstream of the exposed super-alloys. The paper presents the post-irradiation analysis results which reveal interesting damage reversal by the super-invar and unexpected low threshold of radiation resistance by the “gum” metal. Work performed under the auspices of the US DOE.

MOPC110	Commissioning of the Heidelberg Cryogenic Trap for Fast Ion Beams (CTF)	vacuum, cryogenics, ion, target	319
	M. Lange, K. Blaum, M. Froese, M. Grieser, D. Kaiser, S. Menk, D. Orlov, A. Shornikov, T. Sieber, J. Varju, A. Wolf, R. von Hahn MPI-K, Heidelberg O. Heber, M. Rappaport, J. Toker, D. Zajfman Weizmann Institute of Science, Physics, Rehovot
	At the MPI für Kernphysik, a cryogenic electrostatic heavy-ion storage ring (CSR) is being developed. As a cryogenic test facility (CTF), an electrostatic ion beam trap is nearing completion. It will store ions between two electrostatic mirrors, confining them radially by two einzel lenses set apart by 30 cm. This linear, open design leaves room for testing beam diagnostic devices developed for the CSR, e.g. split ring electrodes and a residual gas monitor. As for the CSR, parts of the vacuum system will be brought in direct contact with superfluid helium, to achieve an operating temperature of 2-10 K. Under these conditions, we expect residual gas pressures in the 10^-15 mbar range, and storage times on the order of minutes for light molecular ions. We will present first results from the commissioning of the CTF, especially the temperatures and residual gas pressures reached in the trap, as well as experiences with the position stability of the mechanical suspension of the trap electrodes in cryogenic operation.

MOPD005	Recent Activities in ILC R&D at Hitachi	vacuum, superconducting-RF, cryogenics, insertion	457
	T. Semba, Y. Itou, S. Kajiura, Y. Tsujioka, T. Yoshinari Hitachi Ltd., Ibaraki-ken M. Abe Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken H. Hayano, Y. Higashi, S. Noguchi, N. Ohuchi, K. Saito, K. Tsuchiya KEK, Ibaraki N. Torii Hitachi High-Technologies Corp., Ibaraki-ken
	We participated in the construction of STF (Superconducting RF Test Facility) cryomodule. This paper describes our recent activities in ILC R&D.

MOPD017	G4Beamline Program for Radiation Simulations	simulation, shielding, target, controls	481
	K. B. Beard, T. J. Roberts Muons, Inc, Batavia P. Degtiarenko Jefferson Lab, Newport News, Virginia
	G4beamline, a program that is an interface to the Geant4 toolkit that we have developed to simulate accelerator beamlines, is being extended with a graphical user interface to quickly and efficiently model experimental equipment and its shielding in experimental halls. The program is flexible, user friendly, and requires no programming by users, so that even complex systems can be simulated quickly. This improved user interface is of much wider application than just the shielding simulations that are the focus of this project. As an initial application, G4beamline is being extended to provide the simulations that are needed to determine the radiation sources for the proposed experiments at Jefferson Laboratory so that shielding issues can be evaluated. Since the program already has the capabilities needed to simulate the transport of all known particles, including scattering, attenuation, interactions, and decays, the extension involves implementing a user-friendly graphical user interface for specifying the simulation, and creating general detector and shielding component models and interfacing them to existing Geant4 models of the experimental halls.

MOPD018	Energy Dependent Measurements of Gamma and Neutron Dose at ANKA	undulator, storage-ring, optics, electron	484
	I. Birkel, E. Huttel, A.-S. Müller, N. J. Smale, P. Wesolowski FZK, Karlsruhe
	Gamma and neutron radiation dose rate around an electron storage ring are proportional to the number of lost particles in a certain time. They are depending on beam energy, current, lifetime and operating conditions of the storage ring. The online area monitoring network of ANKA makes it possible to measure the radiation from the decaying beam at eight stations distributed all over the ANKA hall. Measurements of the ambient dose at beam energies from 800 MeV to 2.5 GeV show higher dose rates around and in the forward direction of insertion devices and other devices with restricted horizontal or vertical aperture.

MOPD027	AMC-based Radiation Monitoring System	monitoring, controls, power-supply, electron	505
	D. R. Makowski, A. Napieralski, A. Piotrowski TUL-DMCS, Łódź S. Simrock DESY, Hamburg
	This paper reports a novel radiation monitoring system able to monitor gamma and neutron radiation in an accelerator tunnel in the nearest proximity of the electronic components of the control system. The monitoring system is designed as an Advanced Mezzanine Module (AMC) and it is dedicated for the Low Level Radio Frequency (LLRF) control system based on the Advanced Telecommunication Computing Architecture (ATCA). The AMC module is able to communicate with LLRF control system using both I2C interface defined by Intelligent Platform Management Interface (IPMI) standard and PCI Express. The measured gamma radiation dose and neutron fluence are sent to data acquisition computer using Ethernet network and stored in a database. Static Random Access Memory (SRAM) is applied as a neutron dosimeter. The principle of the detector is based on the radiation effect initiating the Single Event Upsets (SEUs) in a high density microelectronic SRAMs. A well known RadFET dosimeter is used to monitor gamma radiation.

MOPD030	The LHC radiation monitoring system for the environment and safety: from design to operation	monitoring, controls, injection, collider	514
	L. Scibile, D. Forkel-Wirth, H. G. Menzel, D. Perrin, G. Segura Millan, P. Vojtyla, M. Widorski CERN, Geneva
	The RAdiation Monitoring System for the Environment and Safety (RAMSES) has been installed and successfully commissioned. The system was originally designed for the Large Hadron Collider (LHC), it was extended to the CNGS and it is also planned to further extend it to the rest of the CERN accelerators. This state-of-the-art radiation monitoring and alarm system provides permanent ambient dose equivalent rates and ambient dose equivalent measurement in the underground areas as well as on the surface inside and outside the CERN perimeter; it permanently monitors air and water released from the LHC and CNGS installations; it also integrates some conventional environmental measurement such as physicochemical parameters of released water. This paper illustrates the experience gained during the various project phases outlining the problems encountered and the solutions implemented. In addition, it gives a first feedback on the operational experience gained with the CNGS.

MOPD031	Automatic Implementation of Radiation Protection Algorithms in Programs Generated by GCC Compiler	controls, insertion, synchrotron	517
	A. Piotrowski, D. R. Makowski, A. Napieralski, Sz. Tarnowski TUL-DMCS, Łódź
	Radiation influence on microprocessor-based systems is serious problem especially in places like accelerators and synchrotrons, where sophisticated digital devices operate closely to the radiation source. Reliability of such systems is significantly decreased due to effects like SEU or SEFI. One of the possible solutions to increase radiation immunity of the microprocessor systems is a strict programming approach known as Software Implemented Hardware Fault Tolerance. SIHFT methods are based on the redundancy of variables or procedures. Sophisticated algorithms are used to check the correctness of control flow in application. Unfortunately, manual implementation of presented algorithms is difficult and can introduce additional problems with program functionality cased by human errors. Proposed solution is based on modifications of the source code of the C language compiler. Protection methods are applied at intermediate representation of the compiled source code. This approach makes it possible to use standard optimization algorithms during compilation. In addition, a responsibility for implementing fault tolerant is transferred to the compiler and is transparent for programmers.

MOPD032	Neutronics Calculations to Support the SNS Accelerator Facility	shielding, proton, target, linac	520
	I. I. Popova, G. W. Dodson, P. D. Ferguson, J. Galambos, F. X. Gallmeier ORNL, Oak Ridge, Tennessee
	The Spallation Neutron Source (SNS) is an accelerator driven neutron scattering facility for materials research that recently started operations. After commissioning, the facility started at low power and is presently in the process of a power ramp to reach the Megawatt power level within two years of operations, maintenance, and tuning cycles. Extensive neutronics work for shielding development and dose rate predictions was completed during design and construction for various operational and shut down scenarios. Now that the facility is successfully operating, there is still demand for neutronics analyses for radiation-protection support. This need arises from redesigning some parts of the facility, facility upgrades, designing additional structures, designing test stands for accelerator structures, and verification and code validation analyses on the basis of the measured data.

MOPD038	First Radiation Monitoring Results During Elettra Booster Commissioning	booster, injection, shielding, monitoring	535
	K. Casarin, E. Quai, S. Sbarra, G. Tromba, A. Vascotto ELETTRA, Basovizza, Trieste
	The new injection system for the Elettra storage ring is based on a 100 MeV linac and a booster synchrotron, where the electron energy can be raised up to 2.5 GeV. The new machine is designed to perform full energy injection, also in top-up mode. Outside the shielding, radiation monitoring is performed through a real-time network of gamma and neutron dosimeters as well as through TLD passive dosimeters. The radiation monitors placed next to the beamlines are interlocked with the machine operation and prevent injection into the storage ring if the alarm threshold is exceeded. This paper reports the first results of the radiation monitoring performed during the new injector commissioning.

MOPD039	The Personnel Safety System of the Elettra Booster	booster, storage-ring, controls, injection	538
	K. Casarin, L. Battistello, S. Fontanini, F. Giacuzzo, M. Lonza, E. Quai, S. Sbarra, G. Tromba, A. Vascotto, L. Zambon ELETTRA, Basovizza, Trieste
	The new injector of the Elettra storage ring is based on a 100 MeV linac feeding a 3 Hz booster synchrotron. The booster is designed to accelerate the electron beam up to the maximum energy of 2.5 GeV, providing full-energy injection into the storage ring. The Personnel Safety System (PSS) of the new injector protects personnel from radiation hazards by controlling access to restricted areas and interrupting the machine operation in case unsafe conditions occur. The system is based on Programmable Logic Controller (PLC) technology providing redundant logic in a fail-safe configuration. This paper describes the radiation safety criteria that have been defined to minimize radiation exposure hazards as well as the technology and architecture chosen for the PSS implementation.

MOPD041	The SSRF Radiation Safety Interlock System	booster, controls, storage-ring, linac	541
	X. J. Xu, J. H. Cai, J. Cai, K. M. Fang, Z. D. Hua, X. Liu, J. H. Wang, J. Q. Xu SINAP, Shanghai
	Radiation Safety Interlock System (RSIS) for the Shanghai Synchrotron Radiation Facility (SSRF) is composed of two subsystems, the Access Control System (ACS) and the radiation containment system (RCS).The ACS prevents personnel from being exposed to the extremely high radiation inside the SSRF shielding tunnel (or called the interlock area) during machine operation. The RCS prevents personnel from being exposed to the high radiation outside a shielding tunnel during either normal or abnormal operation. The implementation of the ACS is based on the Programmable Logic Controllers, key transfer interlocking systems and IC card system. The RSIS is based on fail-safe, redundancy, multiplicity. Any violation of the RSIS will result in the inhibiting of redundant permission to the associated interlock systems, and cease the injection process and eliminate the entire stored electron beam in the SSRF. This paper describes the design philosophy, the logic, and the implementation of the RSIS at SSRF.

MOPP023	Test of Short Period SC Undulator	undulator, positron, electron, vacuum	595
	A. A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We represent details of design and results of test of 4-m long undulator in cryostat having period 12mm and aperture ~6.35 mm allowing K=1.0. This undulator can be used in ILC positron conversion system as well as insertion device for developing FEL systems.

MOPP031	Challenges and Concepts for Design of an Interaction Region with Push-pull Arrangement of Detectors - an Interface Document	shielding, alignment, interaction-region, collider	616
	A. Seryi, T. W. Markiewicz, M. Oriunno, M. K. Sullivan SLAC, Menlo Park, California D. Angal-Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire B. Ashmanskas, V. R. Kuchler, N. V. Mokhov Fermilab, Batavia, Illinois K. Buesser DESY, Hamburg P. Burrows OXFORDphysics, Oxford, Oxon A. Enomoto, Y. Sugimoto, T. Tauchi, K. Tsuchiya KEK, Ibaraki A. Herve, J. A. Osborne CERN, Geneva A. A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York B. Parker BNL, Upton, Long Island, New York T. Sanuki Tohoku University, School of Scinece, Sendai J. Weisend NSF, Arlington H. Y. Yamamoto Tohoku University, Sendai
	Two experimental detectors working in a push-pull mode has been considered for the Interaction Region of the International Linear Collider [1]. The push-pull mode of operation sets specific requirements and challenges for many systems of detector and machine, in particular for the IR magnets, for the cryogenics system, for alignment system, for beamline shielding, for detector design and overall integration, and so on. These challenges and the identified conceptual solutions discussed in the paper intend to form a draft of the Interface Document which will be developed further in the nearest future. The authors of the present paper include the organizers and conveners of working groups of the workshop on engineering design of interaction region IRENG07 [2], the leaders of the IR Integration within Global Design Effort Beam Delivery System, and the representatives from each detector concept submitting the Letters Of Intent.

MOPP037	Alignment of the CLIC BDS	alignment, multipole, simulation, luminosity	628
	A. Latina, D. Schulte, R. Tomas CERN, Geneva
	Aligning the CLIC Beam Delivery System faces two major challenges, the tight tolerances for the emittance preservation and its strong non-linear beam dynamics. For these reasons conventional beam-based alignment techniques, like dispersion free steering, are only partially successful and need to be followed by optimization algorithms based on other observables, like beam sizes.

MOPP038	Optimizing the CLIC Beam Delivery System	luminosity, synchrotron, synchrotron-radiation, emittance	631
	R. Tomas BNL, Upton, Long Island, New York H.-H. Braun, M. Jorgensen, D. Schulte CERN, Geneva
	The optimization of the new CLIC Final Focus System (FFS) with L*=3.5m is presented for a collection of CLIC beam parameters. The final performance is computed for the full Beam Delivery System including the new diagnostics section. A comparison to previous designs is also presented.

MOPP079	Studies on the Role of a Photon Collimator for the ILC Positron Source	photon, undulator, positron, simulation	733
	L. Zang Cockcroft Institute, Warrington, Cheshire I. R. Bailey, A. Wolski, L. Zang Liverpool University, Science Faculty, Liverpool
	Use of a helical undulator in the ILC positron source provides the possibility of producing a polarised positron beam. The degree of polarisation of the positrons depends upon the polarisation of the photons produced from the undulator, where the polarisation depends on the photon energy and production angle. We calculate these quantities for one design of the helical undulator for the ILC, investigate approximations commonly made in calculating the undulator photon spectrum and explore the role of of a photon collimator in determining the positron polarisation.

MOPP084	Installation and Commissioning of the RF System for the New Elettra Booster	booster, storage-ring, injection, controls	745
	A. Fabris, M. Bocciai, L. Bortolossi, M. Ottobretti, C. Pasotti, M. Rinaldi ELETTRA, Basovizza, Trieste
	The commissioning of the new booster of the Elettra synchrotron radiation source started in Fall 2007. The RF system of the booster is made of a five cells accelerating cavity fed by a 60 kW 500 MHz power plant. The accelerating cavity voltage is ramped along with the booster energy at a 3 Hz repetition rate. The cavity field is controlled by analog feedback loops on amplitude, phase and the resonant frequency. This paper describes the setting into operation of the system and its performances during the commissioning phase of the machine.

MOPP106	Study of Radiation From RF Cavities	photon, electron, acceleration, background	805
	R. Sandstrom DPNC, Genève D. Huang IIT, Chicago, Illinois J. Norem ANL, Argonne, Illinois
	Essential for muon accelerators such as neutrino factories or muon colliders, ionization cooling channels use RF cavities to restore the energy lost in liquid hydrogen absorbers. One major limitation in cooling comes from electrons emitted from the cavities which can cause breakdowns or unacceptable thermal load to the liquid hydrogen vessels. In the Muon Ionization Cooling Experiment MICE, these electrons also cause background in the detectors. This paper presents simulations related to these dark currents, and analysis of data from a direct measurement of this radiation in the MuCool Test Area (MTA).

MOPP114	Design of the Prototypical Cryomodule for the EUROTRANS Superconducting Linac for Nuclear Waste Transmutation	cryogenics, linac, vacuum, alignment	826
	S. Barbanotti, N. Panzeri, P. Pierini INFN/LASA, Segrate (MI) J.-L. Biarrotte, P. Blache, C. Commeaux, P. Duthil, E. Rampnoux IPN, Orsay M. Souli GANIL, Caen
	One task of the accelerator workpackage of the EUROTRANS program for the design of a nuclear waste transmutation system is dedicated to the engineering and realization of a prototype cryomodule of the high energy section of the linac, equipped with elliptical superconducting niobium cavities. We review here the present status of the design and the planned program that foresees the experimental characterization of the fully equipped cavity and RF system under its nominal operating conditions.

MOPP115	Production and Qualification of Low Thermal Conduction Suspension Supports for the Cold Mass of Long Superconducting Acceleration Modules	cryogenics, simulation, site, controls	829
	S. Barbanotti, M. Bonezzi, M. Todero INFN/LASA, Segrate (MI) C. Engling, K. Jensch, R. Mattusch DESY, Hamburg
	A post is an assembly of a low thermal conduction composite material pipe (fiberglass pipe) and some shrink-fit aluminum and steel discs and rings, designed to provide a mechanical support and a thermal insulation to the cold mass of the long cryomodules of the TTF, which are foreseen also for the XFEL and ILC. We review here the production, testing and qualification for the production of post supports, which have been successfully provided for the cryomodules of the TTF in DESY, the STF in KEK and ILCTA in FNAL.

MOPP117	First Test of the Cornell Single-cavity Horizontal Cryomodule	linac, cryogenics, vacuum, resonance	835
	S. A. Belomestnykh, E. P. Chojnacki, R. Ehrlich, R. P.K. Kaplan, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, P. Quigley, J. J. Reilly, D. M. Sabol, J. Sears, V. D. Shemelin, E. N. Smith, V. Veshcherevich, D. Widger CLASSE, Ithaca
	A single-cavity horizontal test cryomodule (HTC) has been designed and fabricated recently at Cornell University for ERL project. This cryomodule is a shortened version of the full injector cryomodule, which will house five superconducting cavities. It serves as a test bench for new design features and for testing fully dressed two-cell ERL injector cavities. The cryostat design has been optimized for precise cavity alignment, good magnetic shielding, and high cryogenic loads from the RF cavities, input couplers, and HOM loads. The HTC was made long enough so in the future it can accommodate longer, multicell cavities of the ERL main linac. In this paper we report on results from the first full test of the HTC, including RF system and superconducting cavity performance, cryomodule studies and operation of a new 1.8 K cryogenic system.

MOPP125	A Superconducting RF Vertical Test Facility at Daresbury Laboratory	shielding, cryogenics, superconducting-RF, controls	850
	P. A. Corlett, R. Bate, C. D. Beard, B. D. Fell, P. Goudket, S. M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire P. K. Ambattu, G. Burt, A. C. Dexter, M. I. Tahir Cockcroft Institute, Lancaster University, Lancaster
	A superconducting RF vertical test facility (VTF) has been constructed at Daresbury Laboratory for the testing of superconducting RF cavities at 2K. When fully operational, the facility will be capable of testing a 9-cell 1.3 GHz Tesla type cavity. The facility is initially to be configured to perform phase synchronisation experiments between a pair of single cell 3.9GHz ILC crab cavities. These experiments require the cavities to operate at the same frequency; therefore a tuning mechanism has been integrated into the system. The system is described, and data from the initial operation of the facility is presented.

MOPP131	Cryomodule Tests of the STF Baseline 9-cell Cavities at KEK	electron, superconducting-RF, linac, coupling	868
	E. Kako, H. Hayano, S. Noguchi, N. Ohuchi, M. Sato, T. Shishido, K. Watanabe, Y. Yamamoto KEK, Ibaraki
	The STF-Baseline superconducting cavity system, which includes four TESLA-type 9-cell cavities, input couplers and frequency tuners, has been developed for the future ILC project. A 6m-cryomodule including one of four STF-Baseline cavities was assembled for the initial test called the STF Phase -0.5. The first cool-down of the cryomodule and high power tests of the STF-Baseline cavity had been successfully carried at 2 K. The maximum accelerating gradient (Eacc,max) of 19.3 MV/m was achieved in a specific pulse width of 1.5 msec and a repetition of 5 Hz, (23.4 MV/m in a shorter pulse of 0.6 msec). The onset of x-rays radiation was observed at higher field than 15 MV/m, and the measured Qo value was about 5 x 10⁹ at 18 MV/m in accompanied with field emission. The detuning angle of about -13 degrees at 18 MV/m was successfully compensated to nearly zero by a combined operation with both an offset detuning and an optimised applied voltage in the piezo element. String assembly of four STF-Baseline cavities has been stated in Jan. 2008. The second cryomodule test for 4 cavities, called the STF Phase -1.0, is scheduled in this early summer.

MOPP141	Commissioning of the ERLP SRF Systems at Daresbury Laboratory	booster, linac, gun, shielding	889
	P. A. McIntosh, R. Bate, R. K. Buckley, S. R. Buckley, P. A. Corlett, A. J. Moss, J. F. Orrett, S. M. Pattalwar, A. E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire F. G. Gabriel FZD, Dresden A. R. Goulden STFC/DL/SRD, Daresbury, Warrington, Cheshire P. vom Stein ACCEL, Bergisch Gladbach
	The Energy Recovery Linac Prototype (ERLP) has been installed at Daresbury Laboratory and its baseline commissioning completed. The SRF systems for ERLP comprise two 9-cell, 1.3 GHz accelerating cavities in the injector (or Booster) cryomodule, which provide a nominal energy gain of 8 MeV for the injected 350 keV beam from the photo-injector. The beam is then accelerated in an identical two cavity cryomodule in the energy recovery main Linac, giving a final ERLP energy of 35 MeV. Each SRF accelerating cavity is powered by commercially available Inductive Output Tubes (IOTs) and the analog LLRF control system is identical to that employed on the ELBE facility at FZD Rossendorf. This paper details the commissioning experience gained for these systems and highlights the ultimate performance achieved.

MOPP153	Cavity Diagnostics Using Rotating Mapping System for L-band ERL Superconducting Cavity	electron, diagnostics, linac, quadrupole	907
	H. Sakai, K. Shinoe ISSP/SRL, Chiba T. Furuya, T. Takahashi, K. Umemori KEK, Ibaraki M. Sawamura JAEA/ERL, Ibaraki
	We are developing the L-band superconducting cavity for Energy Recovery Linac in Japan. In order to survey the electron emission and the heating spot of the cavity inner surface in detail, cavity diagnostics with the rotating mapping system was applied for the vertical tests of our cavities. Two types of sensor, one of which is the carbon resistor and the other is the Si PIN photo diode, was equipped to detect the temperature rise and electron emission. These two sensor arrays were arranged along the cavity axis and set on the rotating mechanics with servo motor. By rotating the sensor arrays around the cavity axis, a lot of information is obtained all over the cavity surface in detail. It is preferable that the number of sensors will be reduced compared with the usual cavity mapping system by using this rotating mapping system. We have already fabricated the Nb single cell cavities which is optimised for ERL operation and then performed the vertical test of Nb ERL single cell cavities. This paper reports the results of the mapping system with Nb single cell ERL-shape cavities.

TUOAG01	VEPP-2000 Electron-Positron Collider Commissioning and First Results of Round Colliding Beam Tests	electron, injection, vacuum, lattice	956
	Y. M. Shatunov, D. E. Berkaev, I. Koop, A. P. Lysenko, E. Perevedentsev, A. L. Romanov, P. Yu. Shatunov, D. B. Shwartz, A. N. Skrinsky BINP SB RAS, Novosibirsk
	VEPP-2000 electron-positron collider construction has been completed in the Budker INP at the beginning of 2007 year. First beam was captured in a special lattice without final focus solenoids. In this regime all systems of power supplies, machine control and beam diagnostics were calibrated and tuned. In the same mode vacuum chamber treatment by synchrotron radiation was performed with electron beam current up to 150 mA. The first test of the round beam option was performed at the energy of 508 MeV with the solenoidal field 10 T in two interaction straight sections. Studies of the beam-beam interaction have been done in "weak-strong" and "strong-strong" regimes. Measurements of beam sizes in the both cases have indicated a beam behavior similar to expectations for the round colliding beams.
	Slides

TUXM02	Performance and Trends of Storage Ring Light Sources	emittance, storage-ring, photon, brilliance	993
	R. Bartolini Diamond, Oxfordshire
	We present an overview of the performance of the latest generation of operating storage ring light sources. Emphasis is given to the comparison of design parameters to the achieved performances. Trends and innovations of established light sources to meet the increasing user’s demand for high brightness and different time structures will be presented. Report on upgrades and improvements will be given including orbit stability, top-up, feedback systems, lower-ID gap operation and a review of the activities for the generation of ultra-short radiation pulses in storage rings.
	Slides

TUOAM02	The Status of the Daresbury Energy Recovery Linac Prototype	gun, linac, diagnostics, laser	1001
	D. J. Holder, P. A. McIntosh, S. L. Smith STFC/DL/ASTeC, Daresbury, Warrington, Cheshire N. Bliss STFC/DL, Daresbury, Warrington, Cheshire A. R. Goulden STFC/DL/SRD, Daresbury, Warrington, Cheshire
	This paper provides an update on the progress with the building and commissioning of the Energy Recovery Linac Prototype (ERLP). The past year has seen a number of notable achievements as well as a number of obstacles to overcome. The detailed results from the gun commissioning work are described elsewhere at this conference. ERLP is a 35 MeV technology demonstrator being built as part of the UK's R&D programme to develop its next-generation light source (NLS). It is based on a combination of a DC photocathode electron gun, a superconducting injector linac and a main linac operating in energy recovery mode. These drive an IR-FEL, an inverse Compton Back-Scattering (CBS) x-ray source and a terahertz beamline. The priorities for ERLP are to gain experience of operating a photoinjector gun and superconducting linacs; to produce and maintain high-brightness electron beams; to achieve energy recovery from an FEL-disrupted beam; the development of an electro-optic longitudinal profile monitor and to study challenging synchronisation issues. ERLP will also act as an injector for what will be the world's first non-scaling, Fixed-Field Alternating Gradient (FFAG) accelerator called EMMA.
	Slides

TUOCM01	First Measurements of the Longitudinal Bunch Profile at SLAC Using Coherent Smith-Purcell Radiation at 28GeV	background, diagnostics, linear-collider, collider	1026
	V. Blackmore, G. Doucas, B. Ottewell, C. Perry OXFORDphysics, Oxford, Oxon R. Arnold, S. Molloy, M. Woods SLAC, Menlo Park, California M. F. Kimmitt University of Essex, Physics Centre, Colchester
	Coherent Smith-Purcell radiation has been demonstrated as a technique for measuring the longitudinal profile of charged particles bunches in the low to intermediate energy range. However, with the advent of the International Linear Collider, the need has arisen for a non-invasive method of measuring the bunch profile at extremely high energies. Smith-Purcell radiation has been used for the first time in the multi-GeV regime to measure the longitudinal profile of the 28GeV SLAC beam. The experiment has both successfully determined the bunch length, and has also demonstrated its sensitivity to bunch profile changes. The challenges associated with this technique, and its prospects as a diagnostic tool are reported here.
	Slides

TUOCM03	Beam Loss Position Monitoring with Optical Fibres at DELTA	beam-losses, injection, storage-ring, vacuum	1032
	F. Rüdiger, G. Schmidt, K. Wille DELTA, Dortmund W. Goettmann HMI, Berlin M. Koerfer DESY, Hamburg
	Detection of ionising radiation with optical fibres is used to localize beam losses. At DELTA three different systems are in use. Optical Time Domain Reflectometry (OTDR) is used to measure radiation doses along the full length of the storage ring vacuum chamber. Transmission measurement of optical fibre loops is used for surveillance of radiation sensitive objects like Undulator permanent magnets. Integration into the DELTA control system offers the possibility to react on increased doses within several minutes. Detection of Cerenkov radiation offers real-time beam loss position monitoring with single-bunch resolution of 2 ns. With up to four fibres mounted at different positions along the vacuum chamber spatial measurement of beam loss is used to increase injection efficiency.
	Slides

TUPC006	A CompactRIO-based Beam Loss Monitor for the SNS RF Test Cave	beam-losses, controls, diagnostics, power-supply	1050
	W. Blokland, G. Armstrong ORNL, Oak Ridge, Tennessee
	An RF Test Cave has been built at the Spallation Neutron Source (SNS) to be able to test RF cavities without interfering the SNS accelerator operations. In addition to using thick concrete wall to minimize radiation exposure, a Beam Loss Monitor (BLM) must abort the operation within 100 μsec when the integrated radiation within the cave exceeds a threshold. We choose the CompactRIO platform to implement the BLM based on its performance, cost-effectiveness, and rapid development. Each in/output module is connected through an FPGA to provide point-by-point processing. Every 10 μsec the data is acquired analyzed and compared to the threshold. Data from the FPGA is transferred using DMA to the real-time controller, which communicates to a gateway PC to talk to the SNS control system. The system includes diagnostics to test the hardware and integrates the losses in real-time. In this paper we describe our design, implementation, and results.

TUPC007	Numerical and Experimental Investigation of the Contamination of X-ray Beam Position Monitors by Bending Magnet Edge Radiation	dipole, undulator, synchrotron, photon	1053
	C. Bloomer, G. Rehm, C. A. Thomas Diamond, Oxfordshire
	The details of an investigation into bending magnet edge radiation at Diamond are discussed, reviewing the effects of this radiation on X-ray Beam Position Monitoring (XBPM) equipment. For some time it has been recognized that there are difficulties using XBPMs for determining the centre of mass position of an undulator beam due to contamination from bending magnet radiation. While the geometry of the XBPM blades is designed to help reduce background dipole interference, this radiation is known to account for approximately 1% of the signal received, skewing the calculated beam position by several micrometres. We made detailed models of the bending magnet edge radiation using the SRW program and used Matlab to analyse the data. We present this model and compare our prediction to experimental results obtained at Diamond.

TUPC008	Beam Diagnostics with IR Light Emitted by Positron at DAΦNE	diagnostics, positron, synchrotron, synchrotron-radiation	1056
	A. Bocci, A. Clozza, A. Drago, A. G. Grilli, A. Marcelli, A. R. Raco, R. S. Sorchetti INFN/LNF, Frascati (Roma) A. De Sio, L. Gambicorti, E. Pace Università degli Studi di Firenze, Firenze E. P. Emanuele Università degli Studi di Firenze, Firenze M. P. Piccinini Università Roma Tre, Roma J. P. Piotrowski Vigo System Sa, Warsaw
	Real-time beam diagnostics is mandatory in accelerators and represents one of the most challenging issues of modern storage rings and future FEL's. Recently, compact mid-IR fast uncooled photo-detectors have been used at DAΦNE to monitor single e^- bunches using the SINBAD IR beamline installed on the e^- ring. Electron bunches have a FWHM of 150-300 ps and are separated by 2.7 ns. Detectors performances are then suitable for a compact and low cost bunch-by-bunch longitudinal diagnostic device. To improve the DAΦNE diagnostic a bending magnet SR port on the e⁺ ring has been set-up with a HV chamber, a gold-coated plane mirror and a ZnSe window. To collect the SR light and focus radiation on IR detectors allowing the diagnostic of e⁺ a compact optical system has been installed in air after the window. Here we will present the status of the apparatus, the source characteristics, the optical setup and the complete acquisition system. This IR port will allow comparison in the ns time domain between data collected on both rings, and could be also used to improve DAΦNE diagnostics, i.e., identify and characterize bunch instabilities and/or increase the current in the e⁺ ring. M. Cestelli Guidi et al. J. Opt. Soc. Amer. A 22, 2810 (2005). **A. Bocci et al. NIM-A, 580, 190 (2007).

TUPC014	SSRF Injector Diagnostics Commissioning Results	booster, linac, diagnostics, emittance	1074
	Y. Z. Chen, J. Chen, Z. C. Chen, Y. B. Leng, Y. B. Yan, W. M. Zhou SINAP, Shanghai
	This paper presents Injector beam diagnostics layout of the Shanghai Synchrotron Radiation Facility(SSRF) which includes the 150MeV LINAC, booster(3.5GeV) and beam transport lines. The different beam diagnostics monitors for beam current, beam position and beam profile are briefly described. The beam diagnostics data acquisition architecture is introduced. Commissioning Results of the 150Mev LINAC are presented, as well as the commissioning status of the booster .

TUPC018	New Experimental Results with Optical Diffraction Radiation Diagnostics	electron, background, target, shielding	1083
	E. Chiadroni, M. Castellano INFN/LNF, Frascati (Roma) A. Cianchi INFN-Roma II, Roma K. Honkavaara, G. Kube DESY, Hamburg
	The characterization of the transverse phase space for high charge density and high energy electron beams is demanding for the successful development of the next generation light sources and linear colliders. The interest in a non-invasive and non-intercepting beam diagnostics is increasingly high due to the stringent features of such beams. Optical Diffraction Radiation (ODR) is considered as one of the most promising candidates to measure the transverse beam size and angular divergence, i.e. the transverse emittance. An experiment, based on the detection of the ODR angular distribution, has been set up at DESY FLASH Facility to measure the electron beam transverse parameters. In this paper we report the recent results on the incoherent diffraction radiation produced by a 1 GeV energy electron beam going through a rectangular slit.

TUPC030	Transverse Electron Beam Size Effect on the Bunch Profile Determination with Coherent Radiation Diagnostics	optics, electron, diagnostics, free-electron-laser	1113
	O. Grimm, H. Delsim-Hashemi, J. Rossbach Uni HH, Hamburg V. Balandin, N. Golubeva DESY, Hamburg
	Longitudinal diagnostics of electron bunches can be done by measurement of coherent radiation (e.g., in the form of transition radiation) and subsequent extraction of the form factor. By measuring short wavelengths, fine structures in the bunch can be resolved. However, the form factor depends on the three-dimensional charge density distribution, and the usual practice of considering only a one-dimensional line charge in interpreting the radiation spectra is questionable, as the finite transverse extend of the electron bunch can reduce the form factor magnitude at short wavelengths. An experimental study of this issue using a two stage single shot spectrometer has been carried out at the FLASH free-electron laser at DESY, Hamburg. The coherent transition radiation spectra for two beam optics settings were recorded and compared. In one setting the transverse beam size at the transition radiation target screen has been blown up by a factor of about 3.5 compared to the second setting. The ratio of these two spectra shows a suppression of radiation intensity at short wavelengths, as expected from a theoretical calculation. In this paper the result of this study is presented.

TUPC031	Longitudinal Beam Diagnostics Application of Synchrotron Radiation at FLASH	synchrotron, synchrotron-radiation, electron, monitoring	1116
	O. Grimm, J. Rossbach Uni HH, Hamburg C. Behrens, B. Schmidt DESY, Hamburg
	For the operation of the FLASH free electron laser at DESY, Hamburg, tools to measure the longitudinal charge distribution and especially its stability over time are important for efficient machine running. Several techniques using both coherent far-infrared and incoherent visible synchrotron radiation from the two bunch compressor chicanes are summarized and compared in this paper. The experimental setups used are a Martin-Puplett interferometer with both a room-temperature pyroelectric and a liquid-Helium cooled bolometer as detector, a streak camera to directly measure the time profile, the analysis of intensity fluctuations of the optical synchrotron radiation measured (with a photomultiplier) through a narrow filter, a single shot grating spectrometer covering the spectral range from 5 μm to 150 μm. Data from the various and complementary experimental methods will be presented and compared.

TUPC036	Multi-wire Profile Monitor for J-PARC 3GeV RCS	injection, electron, linac, superconductivity	1131
	S. Hiroki, N. Hayashi, M. Kawase, F. Noda, P. K. Saha, H. Sako, H. Takahashi, A. Ueno JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken Y. Arakida, S. Lee, T. Toyama KEK, Ibaraki
	A set of six multi-wire profile monitors (MWPMs) has been installed in the injection line and the successive H0 dump line of the RCS (Rapid-Cycling Synchrotron), and contributed to the initial RCS commissioning for establishing an optimum injection orbit. The Au coated W wires (0.1 mm dia.) for the H^- beam detection are fixed to a ceramic wind frame for two directions (horizontal and vertical with 17.7 ^o tilt, typically 51 wires with 2.9 mm or 9.5 mm distance), and the frame can be scanned for horizontal or vertical direction by using a stepping-motor driven actuator. A combination of the 17.7 ^o tilt wires and the precise scan function provides two step measurements, i.e. a rough profile is obtained only at one shot, and a detailed profile is measured for typically 101 shots (10 mm scan at 0.1 mm interval) thereafter. The beam induced charge signals are amplified by the instrumentation pre-amps located in a basement sub-tunnel at distances of 30-40 m from the frame through the shielded twisted pair cables. The signals are further transferred to the sample, hold and multiplex circuits at the ground floor. The digitized profile data are processed to the Gaussian fitting.

TUPC037	Development, Production and Testing of 4500 Beam Loss Monitors	vacuum, beam-losses, simulation, target	1134
	E. B. Holzer, P. Chiggiato, B. Dehning, G. Ferioli, V. Grishin, J. M. Jimenez, M. Taborelli, I. Wevers CERN, Geneva A. Koshelev, A. Larionov, V. Seleznev, M. Sleptsov, A. Sytin IHEP Protvino, Protvino, Moscow Region D. K. Kramer TUL, Liberec
	Beam-loss monitoring (BLM) is a key element in the LHC machine protection. 4250 nitrogen filled ionization chambers (IC) and 350 secondary emission monitors (SEM) have been manufactured at the Institute for High Energy Physics (IHEP) in Protvino, Russia, following their development at CERN. Signal speed and robustness against ageing were the main design criteria. Each monitor is permanently sealed inside a stainless-steel cylinder. The quality of the welding was a critical aspect during production. The SEMs are requested to hold a vacuum of 1·10^-7 bar. Impurity levels from thermal and radiation-induced desorption should remain in the range of parts per million in the ICs. The difference in sensitivity is about 3·10⁴. To avoid radiation aging (up to 2·10⁸ Gy in 20 years) production of the chambers followed strict UHV requirements. IHEP designed and built the UHV production stand. Due to the required dynamic range of 1·10⁹, the leakage current of the monitors has to stay below 1 pA. Several tests during and after production were performed at IHEP and CERN. A consistently high quality during the whole production period was achieved and the tight production schedule kept at the same time.

TUPC046	Study on Longitudinal Phase-space of High-brightness Electron Beams at ISIR, Osaka University	electron, vacuum, photon, linac	1161
	R. Kato, T. Igo, G. Isoyama, S. Kashiwagi, M. Morio ISIR, Osaka
	The performance of the free-electron laser based on self-amplified spontaneous emission strongly depends on characteristics of the electron beam, such as its transverse, longitudinal, and energy profiles as well as bunch charge. The longitudinal phase-space for the electron beam consists of the longitudinal position and energy of electrons, and several methods are extensively under study to evaluate the phase-space profile of the electron beam. We are developing a measurement system consisting of a profile monitor, a bending magnet and a streak camera. We first considered an optical transition radiation monitor as the profile monitor, but we could not get the efficient number of photons to obtain the phase-space images since the angular distribution of the transition radiation is too large to concentrate in the electron energy region of 10 – 20 MeV. In order to increase the number of photons, we have changed to a Cherenkov radiator using a hydrophobic silica aerogel. The Cherenkov radiator was installed in the beam transport line from the linac to the FEL system. We will present an outline of the phase-space measurement system and preliminary experimental results.

TUPC047	Optical Transition Radiation Interferometry for the A0 Photoinjector	electron, scattering, vacuum, optics	1164
	G. M. Kazakevich BINP SB RAS, Novosibirsk H. T. Edwards, R. P. Fliller, S. Nagaitsev, J. Ruan, R. Thurman-Keup Fermilab, Batavia, Illinois
	OTR interferometry (OTRI) is a promising diagnostic technique and was successfully developed and used for investigation of relativistic beams. For mid-energy accelerators the technique is traditionally based on thin polymer films (the first one is transparent for visible light) providing the beam multiple scattering of about 1 mrad or less. The disadvantage of these films is the unacceptable vacuum properties for photoinjectors and accelerators using superconducting cavities. We studied the application of thin mica sheets for OTRI diagnostics at the A0 Photoinjector in comparison with 2.5 μm thick Mylar films. This diagnostic is also applicable for the ILCTA-NML accelerator test facility that is planned at Fermilab. The experimental setups of the OTR interferometer for the A0 Photoinjector are described in the report. Results of simulations and measurements and comparison of the results obtained using Mylar and Mica-based interferometers are presented and discussed.

TUPC066	Temporal Spot Size Evolution of the DARHT First Axis Radiographic Source	ion, electron, target, focusing	1206
	B. T. McCuistian, D. C. Moir, E. A. Rose LANL, Los Alamos, New Mexico H. Bender, C. Carlson, C. G. Hollabaugh, R. Trainham NSTec, Los Alamos, New Mexico
	DARHT is the Dual Axis Radiographic Hydrodynamic Test Facility at Los Alamos National Laboratory. The radiographic spot size is a critical parameter in the performance of the facility to produce quality radiographs. Time resolved images of the radiographic spot of the First Axis of the DARHT facility have been acquired and correlated with the radiation pulse. Analysis of these time resolved images illustrates the effect of beam target interaction on the temporal evolution of the spot size. An explanation of the experimental setup and analysis of the data will be presented.

TUPC073	A Real-time Bunch Length Terahertz Interferometer	diagnostics, electron, optics, linac	1218
	G. Andonian, G. Travish UCLA, Los Angeles, California S. Boucher, P. Frigola, A. Y. Murokh RadiaBeam, Marina del Rey
	With the recent development of advanced photoinjectors and next generation light sources, the progression towards high-current, ultra-short beams is very important. The measurement of these short pulses, with sub-picosecond resolution is essential for successful beam operation and optimization. This paper describes the development of a real-time, shot-to-shot bunch length diagnostic utilizing a novel beam auto-correlation technique.

TUPC074	Beam Transverse Size Effects on the Transition Radiation Energy Spectrum	electron, photon, diagnostics, luminosity	1221
	G. L. Orlandi ENEA C. R. Frascati, Frascati (Roma)
	A theoretical model for the transition radiation emission by a relativistic electron bunch is here presented. Such a model, based on an extension of the virtual quanta method to the case of high density charged beams, predicts the existence of beam transverse size effects on the short wavelength part of the transition radiation energy spectrum. The relevance of such effects to the transition radiation based beam diagnostics of an electron linear accelerator is discussed. The physical consistency of the proposed theoretical model for the transition radiation emission is demonstrated on the basis of the constraints imposed by the temporal causality and Huygens-Fresnel principles. Further arguments in favour of such a thesis, which concern the relativistic nature of the radiative mechanism, are discussed. A possible experiment, devoted to a crosscheck of the theoretical results in an electron linear accelerator, is also proposed.

TUPC075	Development Status of a Beam Diagnostic System with a Spatial Resolution of Ten Micron-meters for XFEL	electron, laser, undulator, target	1224
	Y. Otake RIKEN Spring-8 Harima, Hyogo H. Ego, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken A. Higashiya, S. I. Inoue, H. Maesaka, T. Shintake, M. Yabashi RIKEN/SPring-8, Hyogo
	Aroud 10 micron-meter stability of an electron beam is required along the undulator section of XFEL to stably generate an X ray laser, and comparable resolution is also required for beam position and size measurements. At SPring-8, the construction of an 8 GeV linac with undulators is now in progress to realize the X ray laser driven by such highly qualified electron beams. To obtain these beams, measurements of the spatial and temporal beam structures are very important. We are developing a beam diagnostic system with a measurement resolution of less than 10 micron-meters. The system comprises a cavity type beam position monitor, an optical transition radiation profile monitor, a beam current monitor, an rf beam deflector to diagnose femto-second order temporal structure, and beam slits to shape appropriately beam spatial structure. The arrangement of these instruments were decided by requirements of the beam position and size measurements based on beam optics design. This paper describes the development status of the beam diagnostic system. The test results and design of the instruments showed sufficient performance to realize the above mentioned measurement resolution.

TUPC083	A Diagnostics Plate for the IFMIF-EVEDA Accelerator	diagnostics, emittance, dipole, quadrupole	1248
	I. Podadera Aliseda, B. Brañas, J. M. Carmona, A. Ibarra, C. Oliver CIEMAT, Madrid P.-Y. Beauvais, J. Marroncle, A. Mosnier CEA, Gif-sur-Yvette
	The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. It is essential then to implement the necessary instrumentation for the commissioning, operation and correct characterization of the beam properties of the accelerator prototype. To achieve this goal, a complete set of instrumentation will be installed in the last part of the accelerator, just before the beam dump, in the so-called Diagnostics Plate (DP). It must allow the measurement of the main parameters of the beam: current, phase, position, transverse profile, energy, transverse halo, transverse emittance and longitudinal profile. The main challenges of such a measurement are the high damage power of the low-energy cw 125 mA beam, which precludes the use of interceptive instrumentation. In addition, the DP will not only be used during operation but also during the commissioning of the different accelerating structures at 5 and 9 MeV. In this contribution, the requirements imposed to the instrumentation, the type of techniques that will be used and a first conceptual design will be presented.

TUPC086	Pinhole Camera Resolution and Emittance Measurement	emittance, synchrotron, coupling, synchrotron-radiation	1254
	C. A. Thomas, G. Rehm Diamond, Oxfordshire
	Third generation synchrotron light source are characterised by a low emittance and a low emittance coupling. Some light sources are already proposing to operate with extremely low coupling close to 0.1% and thus vertical emittance approaching 1pm. We derive the limits for the emittance coupling measurement due to the resolution of the X-ray pinhole camera. We also show that it is possible to design a pinhole camera in order to push the limit resolution beyond 0.1% emittance coupling. We then illustrate our calculations with the example of Diamond and compare them with experimental data.

TUPC099	Wire Scanner for Transverse Beam Parameter Measurements in BEPCII	linac, electron, vacuum, simulation	1293
	Y. F. Sui, J. Cao, L. Ma IHEP Beijing, Beijing
	The wire scanner has been installed in the linac injector of BEPCII (Beijing Electron-Positron Collider II) to provide the transverse beam parameters. In the several fellowing months, some experiments will be done. The result will be presented and the reason will be analysed.

TUPC104	On Application of Cherenkov Radiation in Presence of Dispersive Anisotropic Materials to Diagnostics of Ultrarelativistic Beams	plasma, diagnostics, vacuum	1302
	A. V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg
	One of the main methods of diagnostics of charge particles and beams is based on application of Cherenkov radiation. The attractive idea is application of modern metamaterials for these goals. It has been noted that anisotropic dispersive materials can give some important preferences. However imperfection of Cherenkov diagnostics is low sensibility with respect to energies of ultra-relativistic particles having large Lorentz factor. In this work, it will be shown that this limitation can be overcome with help of using special anisotropic dispersive media (they can be produced in the form of artificial metamaterials). Properties of Cherenkov radiation in the presence of such material will be analyzed. The case of unbounded material and the case of waveguide loaded with such material will be considered. It will be shown that the convenient method of determination of Lorentz factor can be based on measurement of frequencies of harmonics generated in the waveguide. This technique allows obtaining good sensibility for very large magnitudes of Lorentz factor. Other possibilities of application of anisotropic and left-handed metamaterials to beam diagnostics will be discussed as well. A. V. Tyukhtin, S. P. Antipov, A. Kanareykin, P. Schoessow. Proc. of PAC07, Albuquerque, NM, USA, p.4156 (2007).

TUPC106	Optimization of Electron Linac Operating Conditions for Photonuclear Isotope Production	target, electron, simulation, isotope-production	1308
	V. L. Uvarov, A. N. Dovbnya, V. I. Nikiforov, Z. V. Zhiglo NSC/KIPT, Kharkov
	The communication describes the method for optimizing the high-power Linac regime (electron energy, pulsed current and beam size, pulse repetition rate) and the composition of output devices to provide the maximum photonuclear yield of isotope product with the maintenance of thermal stability of structural elements. To exemplify, the results of accelerator KUT-30 (45 MeV, 10 kW) optimization at conditions of medical isotope Cu-67 production are reported. Simulation based on a modified PENELOPE/2006 code was employed to compute the Cu-67 generation rate in the Zn target, and also the absorbed radiation power in output device elements for different operating conditions of the accelerator with due regard for its loading characteristic. The simulation results were used to calculate the target and the converter (Ta) temperature at various thicknesses of the latter and at real cooling parameters. Conditions have been established for the maximum Cu-67 yield with keeping thermal stability of the target device.

TUPC107	Feed-free Monitoring of Intense High-energy Bremsstrahlung	electron, monitoring, simulation, linac	1311
	V. L. Uvarov, V. I. Nikiforov, V. A. Shevchenko, I. N. Shlyakhov, A. Eh. Tenishev NSC/KIPT, Kharkov
	High-intensity (>10³ W/cm²) bremsstrahlung sources produced on the basis of electron linacs of energy E₀ up to 100 MeV find use in accelerator-driven subcritical assemblies, in photonuclear isotope production, activation analysis, etc. These processes, as a rule, call for maintaining a stable bremsstrahlung flow for one or more days. Therefore the diagnostic means of the radiation must function reliably under conditions of high-absorbed doses (≥10⁸ Gy). To solve the problem, it is proposed to use a direct charge detector (DCD). It consists of two vacuum gap-spaced metal plates of different thickness. The simulation method based on the software PENELOPE/2006 was used to investigate the conditions of equilibrium e, X-radiation formation in the area of detector location, the dependence of detector sensitivity in its standard geometry on the atomic number Z of the plate material and the gammas energy at E₀ ranging from 20 to 100 MeV. The realization of the method has been demonstrated by experiment with the use of the DCD prototype. The proposed detector requires no external power supply, is easy to operate and has a high radiation resistance.

TUPC110	Bunch Diagnostics with Coherent Infrared Undulator Radiation at FLASH	undulator, electron, diagnostics, background	1320
	A. Willner, H. Delsim-Hashemi, O. Grimm, J. Rossbach Uni HH, Hamburg B. Schmidt DESY, Hamburg
	The operation of the FLASH free electron laser at DESY, Hamburg, requires a high electron beam quality, one important parameter being the longitudinal charge distribution. As a new tool for investigations using coherent radiation techniques, FLASH has been equipped with an electromagnetic undulator. The device is tunable up to a maximum K-Value of 44, corresponding to 200 um wavelength at an electron energy of 500 MeV. The emitted radiation has been characterized in a first measurement campaign using a dispersive spectrometer based on reflective blazed gratings and a pyroelectric detector, operated in a Nitrogen-purged atmosphere. This paper will summarize the measurements and the results obtained from a longitudinal diagnostics analysis.

TUPC114	Results from the Optical Replica Experiments in FLASH	laser, electron, undulator, diagnostics	1332
	V. G. Ziemann, G. Angelova UU/ISV, Uppsala J. Boedewadt, S. Khan, A. Winter Uni HH, Hamburg M. Hamberg, M. Larsson, P. M. Salen, P. van der Meulen FYSIKUM, AlbaNova, Stockholm University, Stockholm F. Loehl, E. Saldin, H. Schlarb, E. Schneidmiller, M. V. Yurkov DESY, Hamburg A. Meseck BESSY GmbH, Berlin
	We present experimental results from the optical replica synthesizer, a novel device to diagnose sub-ps electron bunches by creating a coherent optical pulse in the infrared that has the envelope of the electron bunch and analyzing the latter by frequency resolved optical gating methods. Such a device was recently installed in FLASH at DESY. During an experiment period the spatial and temporal overlap of a several ps long electron bunch and a 200 fs laser pulse were achieved within an undulator. Coherent transition radiation due to the induced micro-bunching was observed on a silver-coated silicon screen and varying the timing between electrons and laser pulse produced two-dimensional images of the slices as a function of the longitudinal position within the electron bunch. In a second experiment the strongly compressed electron bunch is modulated by a laser pulse lengthened to about 2 ps and replica pulses that are emitted from a second undulator are observed and diagnosed by frequency resolved optical gating methods.

TUPC123	An Electro-Optic Deflector for a Fast Laser-Wire Scanner	laser, controls	1356
	A. Bosco, G. A. Blair, S. T. Boogert, G. E. Boorman Royal Holloway, University of London, Surrey
	A large aperture electro-optic deflector has been designed, realized and tested for application on a laser-wire scanner for particle accelerators. Results on the important parameters such as deflection strenght, speed and mode quality preservation are shown and discussed.

TUPC125	Status of the Spallation Neutron Source Superconducting RF Facility	vacuum, controls, cryogenics, superconducting-RF	1362
	F. Casagrande, S. Assadi, M. T. Crofford, W. R. DeVan, X. Geng, T. W. Hardek, S. Henderson, M. P. Howell, Y. W. Kang, J. Mammosser, W. C. Stone, D. Stout, W. H. Strong, D. C. Williams, P. A. Wright ORNL, Oak Ridge, Tennessee
	The Spallation Neutron Source (SNS) project was completed without on-site superconducting RF (SRF) facilities. Installation of the infrastructure necessary to maintain and repair the superconducting Linac and to support power upgrade research and development (R&D) is well underway. Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is now complete. These systems were recently operated satisfactorily to test a cryomodule that had been removed from the accelerator and repaired in the cleanroom. A horizontal cryostat has been fabricated and will be soon commissioned. Equipment for cryomodule assembly and disassembly has been installed and used for cryomodule disassembly. Cavity processing equipment, specifically an ultra-pure water system, high pressure rinse system, and vertical test area is being designed and installed. This effort is providing both high-power test capability as well as long-term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF test facility.

TUPC129	LHC Access System: from Design to Operation	controls, injection, monitoring, site	1371
	T. Pettersson, C. Delamare, S. Di Luca, S. Grau, T. Hakulinen, L. Hammouti, F. Havart, J.-F. Juget, T. Ladzinski, M. Munoz Codoceo, P. Ninin, R. Nunes CERN, Geneva
	The paper describes the LHC access control and safety system project, the system's architecture and the experience gathered of commissioning it. This system is made of two parts: the LHC Access Control System and the LHC Access Safety System. Using state of the art redundant, fail-safe PLC's and a supplementary, cabled control loop the LHC Access Safety System guarantees the safety of the personnel in all events. Using industrial components, the LHC Access Control System, regulates the access to the tunnels and experimental areas by identifying the users and checking their authorisations. It allows a remote or automatic operation of the access control equipment and restricts the number of users working simultaneously in the interlocked areas. A first implementation of the architecture is now in production and ensures that only authorized personnel can enter the controlled areas of the LHC complex and this only after permission has been given by the CERN Control Centre. The design, procurement and installation of the entire system took more than 4 years and the commissioning phase lasted about 12 months.

TUPC132	The Strategy between Optimal Control and Energy Saving about Utility System Operation	controls, synchrotron, synchrotron-radiation, simulation	1380
	Z.-D. Tsai, J.-C. Chang NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	Previously, the Taiwan Light Source (TLS) at NSRRC has proven the good beam line quality depend on the utility system stability. Subsequently, several studies including the temperature control of cooling water and air conditioner was in progress for improving the system stability. Due to the importance of energy saving issue, the heavy power consumption of utility system are also discussed and intended to reduce extensively. The paper addresses some experience between optimal control and energy saving about operation of utility system in TLS. This provides a strategy between stability control and power reduction, including the flow balance, inverter usage, facility operation, control philosophy and so on.

TUPC143	Precise RF Control System of the SCSS Test Accelerator	controls, acceleration, feedback, electron	1404
	H. Maesaka, T. Fukui, N. Hosoda, T. Inagaki, T. Ohshima, Y. Otake, H. Tanaka RIKEN/SPring-8, Hyogo T. Hasegawa, S. Takahashi, S. Tanaka JASRI/SPring-8, Hyogo-ken M. K. Kitamura NDS, OSAKA
	We present the development and performance of the low level rf control system of SCSS test accelerator (VUV-FEL facility). The FEL radiation in the wavelength region of 50-60 nm reached saturation in fall 2007. Since then, the FEL intensity fluctuation has been suppressed within 10%. This performance was achieved by stabilizing the rf phase and amplitude of the accelerator. For example, the rf phase stability of the 238 MHz cavity is achieved to be 0.03 degree rms corresponding to 350 fs. Those of other cavities such as C-band (5712MHz) accelerator are also obtained to be several 100 fs. To control the rf phase and amplitude precisely, we have developed an IQ modulator / demodulator system. To treat the baseband signal of the system, we have also developed VME high speed DAC / ADC boards. The phase skew of the IQ system is ± 1.0 degree without correction and ± 0.1 degree after correction. To suppress the slow drift of rf components, we applied a PID feedback control loop to the rf source and cavity system. We also improved temperature stabilization for the acceleration structures.

TUPD020	Remote Alignment of Low Beta Quadrupoles with Micrometric Resolution	alignment, quadrupole, controls, survey	1470
	M. Acar, J. Boerez, A. Herty, H. Mainaud Durand, A. Marin, J.-P. Quesnel CERN, Geneva
	Considering their location in a high radiation environment and the alignment tolerances requested, the Low Beta quadrupoles of LHC will be positioned remotely (controlling 5 degrees of freedom), with a displacement resolution of few microns in horizontal and vertical. Stepping motor gearbox assemblies are plugged into the jacks which support the cryomagnets in order to move them to the desired position regarding the quality of the beam collisions in the detectors. This displacement will be monitored in real time by the sensors located on the magnets. This paper describes the positioning strategy implemented as well as the software tools used to manage it.

TUPD036	G4Beamline Simulations for Detector Development	simulation, electron, electromagnetic-fields, photon	1506
	T. J. Roberts, K. B. Beard Muons, Inc, Batavia
	In current research programs to develop radiation detection instruments, simplifying assumptions are frequently made in estimating the resolutions and efficiencies attainable by neutron and gamma-ray instruments. Monte Carlo programs (such as Geant4) are capable of realistically modeling such problems, but the technical details of setting up, running, and interpreting the required simulations are beyond the ability of all but the most expert researchers. G4beamline, a program that is an interface to the Geant4 toolkit for the simulation of accelerator beam lines, is being extended to model detectors and related systems needed for applications related to nuclear nonproliferation and other users. The program is flexible, extremely user friendly, and requires no programming by users. Simulations of simple or complex detectors can be setup quickly and are accurately simulated using the power and accuracy of Geant4 for the transport of particles, including scattering, attenuation, interactions, and decays.

TUPD037	Design and Development of Intercepting Devices at the Spallation Neutron Source	vacuum, linac, beam-transport, diagnostics	1508
	R. T. Roseberry, S. Assadi, D. W. Crisp, K. R. Gawne ORNL, Oak Ridge, Tennessee
	Beam measurements in the LINAC and transport lines of the Spallation Neutron Source at Oak Ridge National Laboratory utilize a variety of intercepting instruments such as in-line emittance systems, wire scanners, scrapers and scintillation view screens. All of these devices require linear actuators with vacuum feedthroughs. The majority of the actuators acquired during the construction phase of the SNS were of commercial origin and have proven unable to meet long-term physics and engineering requirements. The predominant difficulties with these devices were lack of precision, reliability and longevity. Three new families of linear actuators have been developed at the SNS to address these deficiencies. The approach used in their development, has been to utilize a combination of commercially available linear motion components in custom built chassis to address the needs of a given set of applications. This approach has yielded devices that have met or exceeded expectations for accuracy, precision, radiation resistance, longevity and economy. Aspects of the underlying design of these actuators and their implementation will be presented at this conference.

TUPP003	Automatic Generation of SEU Immunity for FPGA Based Electronics for Accelerators	controls, simulation, free-electron-laser, laser	1529
	M. K. Grecki, G. W. Jablonski, W. Jalmuzna, D. R. Makowski TUL-DMCS, Łódź
	The modern accelerator control systems nowadays are build using digital technology based on FPGA circuits. However, digital circuits working in radioactive environment are exposed to disturbing effects, in particular SEU (Single Event Upset). One of the countermeasure is a redundancy in circuit that allow to detect and correct errors caused by radiation. Unfortunately CAD software provides no support to automatically include required redundancy in the FPGA project. Moreover, optimization procedure removes all redundant parts and special effort must be made to prevent that. The paper presents a software environment to process VHDL description of the circuit and automatically generate the redundant blocks together with voting circuits. The generated redundancy uses Triple Module Redundancy (TMR) scheme. It also supports the VHDL simulation with SEUs in order to enable identification of the most sensitive components*. Since the TMR is costly, the designer can indicate which parts of the circuit should be replicated based on the results of simulation. Baumann. Neutron-induced…, Int. Rel. Phys. Symp. 2000. Hentschke et al. Analyzing Area…, Symp. ICs and Systems Design, SBCCI02. *Grecki. VHDL Simulation…, Nanotech 2006, Vol.1.

TUPP011	The ESRF Temperature Monitoring System from an Operational Point of View	monitoring, vacuum, controls, survey	1547
	D. Schmied, E. Burtin, J. M. Chaize, R. Kersevan, I. Parat, M. Peru, J. L. Pons ESRF, Grenoble
	The vacuum control system of the ESRF electron Storage Ring (SR) is in operation since more than ten years now. Apart from difficulties to have appropriate support for the old system, we start facing problems of aging and obsolescence. We have been reviewing our philosophy of data acquisition and remote control in order to upgrade our systems with state of the art technology by taking into account our operational experience. We have installed shielded "intelligent" devices inside the SR and took advantage of the latest developments linked to new communication technologies and standards, such as TCP/IP MODbus protocol and WEB server based instrument control. This presentation outlines our present work dedicated to the ESRF temperature acquisition system based on Programmable Logic Controllers (PLC), and new developments regarding the user interface in the control room. Several examples show the importance of surveying the temperatures in order to identify various mechanical or operational problems which allow us to anticipate later failures and provide us with an additional machine diagnostic tool.

TUPP014	Control System for a 150 MeV FFAG Complex in KURRI	controls, power-supply, proton, booster	1556
	M. Tanigaki, N. Abe, K. Mishima, Y. Mori, Y. Oki, A. Osanai, S. Shiroya, K. Takami, K. Takamiya, T. Takeshita, A. Taniguchi, H. Yashima, H. Yoshino KURRI, Osaka M. Ikeda, Y. Kijima Mitsubishi Electric Corp, Energy & Public Infrastructure Systems Center, Kobe
	A simple, convenient control system has been developed for a 150 MeV proton FFAG accelerator complex at Research Reactor Institute, Kyoto University(KURRI). This control system is based on conventional PCs and programmable logic controllers (PLC) and these are connected over TCP/IP network. Each PLC is responsible for autonomous control of connected devices such as motors or power supplies, and also responsible for maintaining a parameter database periodic(~100 ms typically) read/written by remote PCs over TCP/IP network. Man-machine interfaces and integrated sequences are developed using LabView environment on these PCs. This control system has been successfully served for the actual operation of the FFAG complex, including the radiation protection control. Further developments, such as portable devices serving man-machine interfaces on site and the integration of SQL server for logging all possible parameters of this accelerator complex, are on the way.

TUPP039	Wake-field Compensation in Energy Recovery Linacs	linac, acceleration, synchrotron, synchrotron-radiation	1628
	G. Hoffstaetter, M. G. Billing, Y. H. Lau CLASSE, Ithaca
	Problems created by the correlated energy spread that wake fields can produce are strongly enhanced in Energy Recovery Linacs (ERLs), as compared to conventional linacs. This is due to the fact that in ERLs the spent beam is decelerated by a potentially large factor, which increases the relative energy spread proportionally. We show how severe this problem is for the impedance budget of the x-ray ERL that Cornell plans to build, and we analyze several different possibilities to compensate the correlated energy spread involving de-phasing linac components, linear and nonlinear time-of-flight terms in different accelerator sections, or high frequency accelerating cavities. Because of the particular design, which has a turn-around loop between two sections of the linac, there are many options for these techniques which we compare and evaluate.

TUPP040	Intra Beam Scattering in Linear Accelerators, Especially ERLs	scattering, linac, simulation, lattice	1631
	G. Hoffstaetter, M. P. Ehrlichman, A. Temnykh CLASSE, Ithaca
	The theories of beam loss and emittance growth by Touschek and Intra Beam Scattering have been formulated for beams in storage rings. It is there that these effects have hitherto been important because of their large currents. However, there are linear accelerators where these effects become important when considering loss rates and radiation damage. Prime examples are high current Energy Recovery Linacs (ERLs), managing these scattering effects can become challenging, and not only because of the large current, but also because the deceleration of the spent beam increases relative energy spread and transverse oscillation amplitudes. In this paper we describe two ways of simulating particle loss by these scattering affects, both implemented in BMAD. One that yields the places where scattering occurs, and another that yields loss rates along the chamber walls. BMAD includes nonlinear beam dynamics, wake effects, and more, which allows a rather complete propagation of scattered particle. For the example of the ERL x-ray facility that Cornell plans to build, we demonstrate that these capabilities are very important for designing a functional radiation protection system.

TUPP041	CSR Shielding in the Beam Dynamics Code BMAD	shielding, synchrotron, synchrotron-radiation, simulation	1634
	G. Hoffstaetter, C. E. Mayes, U. Sae-Ueng, D. Sagan CLASSE, Ithaca
	Short bunches radiate coherently at wavelengths that are longer than their bunch length. This radiation can catch up with the bunch in bends and the electromagnetic fields can become large enough to significantly damage longitudinal and transverse bunch properties. This is relevant for many accelerators that relies on bunch compression. It is also important for Energy Recovery Linacs, where spent beams are decelerated by a potentially large factor. Because this deceleration increases the relative energy spread, all sources of wake fields, especially Coherent Synchrotron Radiation (CSR), become much more important. In this paper we show how the beam dynamics code BMAD computes the effect of CSR and how the shielding effect of vacuum chambers is included by the method of image charges. We compare the results to established codes: to Elegant for cases without shielding and to a numerical solution of simplified Maxwell equations as well as to analytical csr-wake formulas. Good agreement is generally found, and in cases where numerical solutions of the simplified Maxwell equations do not agree with the csr-wake formulas, we show that BMAD agrees with these analytic formulas.

TUPP054	A Model of an Electrical Discharge in the Flange Contacts with Omega Seals at High Currents in PEP-II	vacuum, resonance, synchrotron, synchrotron-radiation	1667
	A. Novokhatski, J. Seeman, M. K. Sullivan SLAC, Menlo Park, California
	During operation with high currents at HER (High Energy Ring), high temperature elevation was found at almost every location of the vacuum chamber flange contacts. Omega RF seals were strongly damaged or even evaporated by sparks and electrical discharge. We suggest a physical model, which may explain this effect.

TUPP055	Loss Factor of the PEP-II Rings	synchrotron, resonance, synchrotron-radiation, luminosity	1670
	A. Novokhatski, M. K. Sullivan SLAC, Menlo Park, California
	RF power balance method is used to measure the synchrotron radiation losses and the wake field losses. We present the history of the loss factor during the last several runs, which reveals many interesting correlations with vacuum chamber improvement and processing.

TUPP094	Recent Improvements in the Tracking Code PLACET	emittance, simulation, alignment, lattice	1750
	A. Latina, H. Burkhardt, G. Rumolo, D. Schulte, R. Tomas CERN, Geneva E. Adli University of Oslo, Oslo Y. Renier LAL, Orsay
	The Tracking Code PLACET has recently undergone several improvements. A redesign of its internal data structures and a new user interface based on the mathematical toolbox Octave have considerably expanded its simulation capabilities. Several new lattice elements, optimization algorithms and physics processes have been added to allow for more complete start-to-end simulations. The usage of the AML language and the Universal Parser Library extened its interfacing capability.

TUPP117	Review of Energy Variation Approaches in Medical Accelerators	linac, electron, coupling, photon	1797
	S. M. Hanna MINA, Danville, California
	Most of cancer Radiation Therapy (RT) machines rely on a linac as the source of the treatment beam which can be an electron beam or an X-ray beam. In either case, an approach to vary the energy of the linac’s output beam may be needed to target cancer tumors of different depths. Over the last two decades, multiple approaches for medical linac energy variation were proposed and some of them have been developed and implemented clinically. The most direct and conventional technique is to vary the amount of the RF power delivered to the linac and hence the energy output as required by the treatment plan. A second approach involves keeping the RF power delivered to the linac fixed but varying the power delivered to different sections of the linac by utilizing a mechanical or an electronic switch that controls the power distribution inside the linac. A third approach is to use two separate linac sections. The first section receives a fixed amount of RF power while the RF power delivered to second section is controlled using conventional microwave power splitting techniques. In this paper we will review the above approaches and discuss the advantages and disadvantage of each technique.

TUPP121	Spatial Resolution and Contrast of the Intensity Modulated Electron Beam by the Photocathode RF Gun for the Radiation Therapy	electron, gun, laser, cathode	1809
	T. Kondoh, K. Kan, H. Kashima, K. Norizawa, A. Ogata, S. Tagawa, J. Yang, Y. Yoshida ISIR, Osaka
	The radiation therapy of cancer is developing to un-uniform irradiation as the Intensity Modulated Radiation Therapy (IMRT), for reduce dose to normal tissue. Toward the IMRT, optical modulation of electron beam is studying by a photocathode RF gun. The photocathode RF gun can generate a low emittance electron beam by laser light. Because of the low emittance beam, the modulated electron beam is able to accelerate keeping shape. Electron beam were monitored by CCD cameras measuring the luminescence of the scintillator. Fundamental data such as the spatial resolution and the contrast of the optical intensity modulated electron beam are necessary. Spatial Resolution and Contrast of the Intensity Modulated Electron Beam by a Photocathode RF Gun will be reported. If the shape of the modulated electron beam is different, it may not keep beam shape from the non-symmetrically of the repulsion of the bunch inside. It will be reported that the relations of the beam-shape and the keeping ability of beam.

TUPP141	Electron Accelerators for Cleaning Flue Gases and for Oil Liquefaction	electron, cathode, vacuum, plasma	1848
	S. Korenev, R. P. Johnson Muons, Inc, Batavia
	High-power electron beams can be used to reduce the environmental impact of coal and oil-fired power generating plants by removing harmful materials from flue gases. This technology has been tested in the laboratory and at smaller industrial levels, but to make it economically attractive, the accelerator costs must be reduced and the efficiency must be increased for removing toxic components in low concentrations. We propose a simple electron accelerator with a wide beam to reduce costs. To remove toxic materials we propose a plasma reactor for desulfurization and selective catalytic reduction. The designs of 0.5 to 1.0 MeV accelerators with 20 to 100 kW average power are considered, along with the design of a plasma reactor for flue gas treatment. The design of a pilot facility for the oil industry is also presented.

TUPP154	Proton Energy Measurement Using Stacked Silicon Detectors	proton, cyclotron, vacuum, target	1866
	K. R. Kim KAERI, Daejon H. J. Kim, J. H. So Kyungpook National University, Daegu
	Proton energy was measured using stacked Si(Li) detectors at the MC-50 cyclotron of KIRAMS (Korea Institute of Radiological and Medical Sciences). The proton energies from the cyclotron were 35 MeV and 45 MeV. Generally, using a single semiconductor detecor it is not available to measure the proton energy above 30 MeV because the maximum thickness of the semiconductor detector was limited to 5mm. We have used a detector consisting of three 2 mm thick Si(Li) detectors and a 5 mm thick one. The active areas of these detectors are 75mm2. In this paper, we report the energy measurement results using the stacked detectors.

TUPP155	Compact EUV Source Based on Laser Compton Scattering between Micro-bunched Electron Beam and CO2 Laser Pulse	laser, electron, scattering, undulator	1869
	S. Kashiwagi, G. Isoyama, R. Kato ISIR, Osaka T. Gowa, A. Masuda, T. Nomoto, K. Sakaue, M. Washio RISE, Tokyo R. Kuroda AIST, Tsukuba, Ibaraki J. Urakawa KEK, Ibaraki
	High-power extreme ultra-violet (EUV) sources are required for next generation semiconductor lithography. We start developing a compact EUV source in the spectral range of 13-14 nm, which is based on laser Compton scattering between a micro-bucnhed electron beam and a high intensity CO2 laser pulse. The electron beam extracted from a DC photocathode gun is micro-bunched using laser modulation techinque and a magnetic compressor before the main laser Compton scattering for EUV radiation. We will describe a considerating scheme for the compact EUV source based on laser Compton scattering with micro-bunched electron beam and the result of its numerical studies. A plan of test experiment generating micro-bunched electron beam will be also introduced in this conference.

TUPP162	High Heat Load Components in TPS Front Ends	synchrotron, undulator, synchrotron-radiation, photon	1890
	A. Sheng, J.-R. Chen, C. K. Kuan, Z.-D. Tsai NSRRC, Hsinchu
	National Synchrotron Radiation Research Center (NSRRC) will build a new synchrotron accelerator (TPS, Taiwan Photon Source) with a great heat-load power. Various IDs have been proposed. For instance, at 3.3 GeV, 350 mA, superconductivity wiggler SW4.8 may generate 5.8mrad wide, 57 kW/mrad² power whereas undulator CU1.8 will be 0.7 mrad, 148 kW/mrad². The function of the fixed mask in TPS front ends not only to protect the downstream vacuum from being hit by the radiation during miss-steering, but also shadow the unwanted power. More than one fixed masks are introduced in some high heat load front ends. High conductivity, high thermomechaical strength GlidCop� is used; design and thermomechanical analysis is also presented in this paper.

WEXM02	Status of the Linac Coherent Light Source	undulator, linac, electron, laser	1939
	J. N. Galayda SLAC, Menlo Park, California
	The Linac Coherent Light Source (LCLS) is a free-electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor were commissioned in 2007. Accelerator commissioning activities are presently devoted to the achievement of performance goals for the completed linac. R. Akre, et al., "Commissioning the LCLS Injector", submitted to PRSTAB, 2007
	Slides

WEOAM02	A Scheme for Stabilization of Output Power of an X-ray SASE FEL	undulator, laser, linac, electron	1947
	E. Schneidmiller, G. Geloni, E. Saldin, M. V. Yurkov DESY, Hamburg
	Stability of XFEL radiation is naturally linked to stability of the linac RF system through bunch compression, leading to very tight requirements on RF amplitude and phase. We propose a new scheme that allows to relax these requirements by a large factor.
	Slides

WEPC013	Commissioning of Medium Emittance Lattice of HLS Storage Ring	emittance, brilliance, lattice, focusing	2013
	G. Feng, W. Li, L. Liu, L. Wang, H. Xu, S. C. Zhang USTC/NSRL, Hefei, Anhui
	Hefei Light Source (HLS) is a second generation light source, whose emittance is about 160 nmrad in normal optics. Lowering beam emittance is the most effective measure to enhance light source brilliance. Considering beam lifetime limitation, a lattice with medium beam emittance was brought forward. Through distributed dispersion in straight section, the beam emittance was reduced to 80 nmrad. At same time, the betatron tunes were kept same as before. In this way, the focusing parameters can be tuned to new one smoothly. With the new lattice parameters, the brilliance of HLS is increased by two factors.

WEPC017	Short X-ray Pulse Generation in Taiwan Photon Source Using Deflecting Cavity	photon, electron, emittance, lattice	2025
	H. Ghasem IPM, Tehran G.-H. Luo NSRRC, Hsinchu
	We have purposed to use deflecting cavity for short X-ray pulses production in 3 GeV Taiwan Photon Source (TPS). Typical electron bunch length in TPS for 1.1MV RF gap voltage is about 5.7mm. Deflecting cavity generates correlation between longitudinal position and vertical momentum of particles in a bunch. Vertical kick of particle separates the photons that emit from ID vertically. Slit and asymmetric crystal in TPS beam line are used to compress the photon pulse duration. For a 60 m beam line of TPS, the operating of deflecting cavity up to 6MV voltage and eighth harmonic yields an FWHM pulse duration of radiated X-ray of about 0.48 ps for users.

WEPC026	Laser – Beam Interaction and Calculation of the Sliced Bunch Radiation Spectra for the SLS FEMTO Beam Line	electron, laser, wiggler, positron	2040
	D. K. Kalantaryan, G. A. Amatuni, V. M. Tsakanov CANDLE, Yerevan P. Beaud, G. Ingold, A. Streun PSI, Villigen
	The FEMTO insertion at the Swiss Light Source (SLS) produces sub-ps X-ray pulses by modulating the electron energy in a slice of the bunch through interaction with a fs-laser. The electron energy modulation by the laser field in the wiggler magnet is studied analytically to calculate the radiation spectra from a sliced bunch. The analytical expressions for energy modulation and its envelope have been derived. The radiation spectra in the first magnet after the FEMTO insertion have been studied. The spectra of the coherent part of the radiation are determined using a Fourier transformation technique. For a Gaussian bunch the obtained results are compared with the tracking simulation study.

WEPC027	Coherent THz Radiation at ELETTRA	electron, synchrotron, synchrotron-radiation, single-bunch	2043
	E. Karantzoulis, G. Penco, A. Perucchi ELETTRA, Basovizza, Trieste S. Lupi Coherentia, Naples
	Coherent infra red radiation (CIR) has been observed since some time at ELETTRA under several machine parameter settings in the beam-line SISSI. Effort has been made to produce a “stable” THz signal for experimental use. The description of the machine settings to that end and the measurements performed are presented and discussed.

WEPC028	Status of UVSOR-II and Light Source Developments	undulator, laser, electron, injection	2046
	M. Katoh, M. Adachi, K. Hayashi, M. Shimada, J. Yamazaki UVSOR, Okazaki M. Hosaka, Y. Takashima, N. Yamamoto Nagoya University, Nagoya A. Mochihashi JASRI/SPring-8, Hyogo-ken
	UVSOR, a 750 MeV synchrotron light source of 53m circumference had been operated for more than 20 years. After a major upgrade in 2003, this machine was renamed to be UVSOR-II. The ring is now routinely operated with low emittance of 27 nm-rad and with four undulators. Top up injection is under preparation. The ring is equipped with a resonator type free electron laser. The shortest wave length has reached 200nm. Several user experiments in the deep UV region are in progress. Coherent terahertz synchrotron radiation and coherent harmonic generation are extensively studied by using an ultra-short laser system, under international collaborations. An upgrade plan of the ring is under consideration to improve the experimental setup of the light source developments.

WEPC032	Absolute Measurement of the MLS Storage Ring Parameters	electron, photon, storage-ring, induction	2055
	R. Klein, G. Brandt, R. Fliegauf, A. Hoehl, R. Müller, R. Thornagel, G. Ulm PTB, Berlin M. Abo-Bakr, K. B. Buerkmann-Gehrlein, J. Feikes, M. V. Hartrott, K. Holldack, J. Rahn, G. Wuestefeld BESSY GmbH, Berlin
	The Metrology Light Source (MLS), the new electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB) located next to BESSY II in Berlin - Adlershof is dedicated to metrology and technology development in the UV and EUV spectral range as well as in the IR and THz region. The MLS can be operated at various electron beam energies up to approx. 600 MeV and at electron beam currents varying from 1 pA (one stored electron) up to 200 mA and is optimized for the generation of coherent synchrotron radiation. Of special interest for PTB is the operation of the MLS as a primary radiation source standard from the visible up to the X-ray region. Therefore the MLS is equipped with all the instrumentation necessary to measure the storage ring parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty. The instrumentation and measurement results for the determination of the storage ring parameters are presented.

WEPC033	Coherent Synchrotron Radiation at the Metrology Light Source of the PTB	electron, synchrotron, synchrotron-radiation, storage-ring	2058
	R. Müller, A. Hoehl, R. Klein, G. Ulm PTB, Berlin M. Abo-Bakr, K. B. Buerkmann-Gehrlein, J. Feikes, M. V. Hartrott, J. S. Lee, J. Rahn, U. Schade, G. Wuestefeld BESSY GmbH, Berlin
	The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has set up a low-energy electron storage ring in Berlin-Adlershof in close cooperation with the BESSY GmbH. The new storage ring, named Metrology Light Source (MLS), is mainly dedicated to metrology and technological developments in the EUV, VUV, and IR spectral range. Additionally, the MLS is the first machine designed and prepared for a special machine optics mode (low-alpha operation mode) based on an octupole correction scheme, for the production of coherent synchrotron radiation in the FIR and THz region. Two beamlines dedicated to the use of IR synchrotron radiation are now under commissioning: an IR bending magnet beamline optimized for the MIR to FIR and an IR edge radiation beamline. We report the status of the MLS operated in the low alpha mode and present first results from the commissioning.

WEPC046	Characterizing THz Coherent Synchrotron Radiation at the ANKA Storage Ring	synchrotron, synchrotron-radiation, single-bunch, storage-ring	2091
	A.-S. Müller, I. Birkel, S. Casalbuoni, B. Gasharova, E. Huttel, Y.-L. Mathis, D. A. Moss, N. J. Smale, P. Wesolowski FZK, Karlsruhe E. Bruendermann Ruhr-Universität Bochum, Bochum T. Bueckle, M. Klein University of Karlsruhe, Karlsruhe
	In a synchrotron radiation source coherent infrared (IR) radiation is emitted when the bunch length is comparable to the wavelength of the emitted radiation. To generate coherent THz (far IR) radiation, the ANKA storage ring is operated regularly in a dedicated low-alpha optics. Different bunch lengths, corresponding to different spectral ranges of the THz spectrum and various electron beam energies can be offered, depending on user demand. The radiation emitted in the fringe field of a dipole magnet, the so-called edge radiation, is detected at the ANKA-IR beamline. This paper presents radiation properties like THz beam profiles and power measurements in the framework of characterising the coherent THz radiation to optimise the power, frequency and spatial output of the ANKA storage ring. First experiments showed a time averaged power of up to 0.2 mW suggesting a THz pulse peak power of at least several tens of mW.

WEPC047	Modeling the Shape of Coherent THz Pulses Emitted by Short Bunches in an Electron Storage Ring	synchrotron, synchrotron-radiation, storage-ring, electron	2094
	A.-S. Müller, S. Casalbuoni, M. Fitterer, E. Huttel, Y.-L. Mathis FZK, Karlsruhe M. T. Schmelling MPI-K, Heidelberg
	A sufficiently short electron bunch will emit coherent synchrotron radiation of wavelengths equal to or larger than the bunch length. The shape of the emitted THz pulse depends amongst other things on the original shape and length of the bunch’s charge distribution. A Michelson interferogram of the THz signal therefore contains information on the generating bunch. However, systematic effects make a bunch length measurement based on that technique non-trivial. In order to understand the variables involved, an analytical model of the pulse generation is needed. In this paper, a derivation of the THz pulse shape form first principles with special emphasis in the time domain is presented. The impact of charge distribution parameters on the Michelson interferogram is discussed.

WEPC049	Novel Schemes for Simultaneously Satisfying High Flux and TOF Experiments in a Synchrotron Light Source	kicker, synchrotron, storage-ring, single-bunch	2100
	D. Robin, G. J. Portmann, F. Sannibale, W. Wan LBNL, Berkeley, California
	Storage Ring Light Sources have proven to be extremeley succesful tools for probing matter. One of their most desirable features is that they are able to supply synchrotron radiation to multiple experiments simultaneously. However two classes of applications are difficult to satisfy simultaneously - high flux applications and time of flight applications. High flux experiments require filling as many buckets as possible while time of flight experiments require long gaps between bunches. In this paper we examine schemes for operating the synchrotron light source for for both communities simultaneously.

WEPC053	An Experimental Study of Radiation-induced Demagnetization of Insertion Device Permanent Magnets	electron, proton, insertion, insertion-device	2112
	N. Simos, P. K. Job BNL, Upton, Long Island, New York N. V. Mokhov Fermilab, Batavia, Illinois
	High brilliance in the 3GeV new light source NSLS II is obtained from the high magnetic fields in insertion devices (ID). The beam lifetime is limited to 3h by single Coulomb scattering in the Bunch (Touschek effect). This effect occurs everywhere around the circumference and there is unavoidable beam loss in the adjacent low-aperture insertion devices. This raises the issue of degradation and damage of the permanent magnetic material by irradiation with high energy electrons and corresponding shower particles. It is expected that IDs, especially those in-vacuum, would experience changes resulting from exposure to gamma rays, x-rays, electrons and neutrons. By expanding an on-going material radiation damage study at BNL the demagnetization effect of irradiation consisting primarily of neutrons, gamma rays and electrons on a set of NdFeB magnets is studied. Integrated doses of several Mrad to a few Grad were achieved at the BNL Isotope Facility with a 112-MeV, 90-uA proton beam. Detailed information on dose distributions and particle energy spectra on the NdFeB magnets was obtained with the MARS15 Monte-Carlo code. This paper summarizes the results of this study. Work performed under the auspices of the US DOE.

WEPC056	Emittance Reduction by Longitudinally Varying Dipole Field	emittance, dipole, dynamic-aperture, optics	2118
	K. Tsumaki JASRI/SPring-8, Hyogo-ken
	One of the most important matters for synchrotron radiation source is decreasing the beam emittance to increase the brightness. The electron beam emittance is almost determined by electron energy and the average H-function. For further improvement of the emittance, we can change the damping partition number by radially varying dipole field and can reduce the emittance. However, this method is not effective for a small emittance lattice due to its small dispersion function. We have studied the emittance reduction by longitudinally varying magnetic field in a bending magnet. The radius of curvature is assumed to vary with the function of nth degree (n=1,2,3,4). The emittance is calculated numerically for minimum emittance and achromat configuration. In this paper, we describe the details of calculated results and discuss the effectiveness of the method.

WEPC057	Preparation for Top-up Operation at Diamond	injection, storage-ring, controls, dipole	2121
	R. P. Walker, P. T. Bonner, F. Burge, Y. S. Chernousko, C. Christou, J. A. Dobbing, M. T. Heron, V. C. Kempson, I. P.S. Martin, G. Rehm, R. J. Rushton, S. J. Singleton, M. C. Wilson Diamond, Oxfordshire R. Bartolini JAI, Oxford
	We report on progress towards top-up operation of Diamond. We describe the extensive safety assessment that has carried out, including the measurements and simulations to assess the potential radiation doses in the case of poor injection efficiency or a top-up "accident", and the various levels of safety measures - procedures, software limits and personnel safety system interlocks - that have been implemented. We describe the top-up control algorithm, the technique used to maintain a given arbitrary filling pattern and the performance in practise. The work carried out to reduce the effect of the injection kickers on the stored beam is described, and the effect of the residual disturbance on user operation is discussed. The modifications to the timing system to provide hardware and software gating signals, and experience with the use of these, are also described.

WEPC063	The Concept of Hefei Advanced Light Source (HALS)	emittance, storage-ring, synchrotron, synchrotron-radiation	2136
	L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang USTC/NSRL, Hefei, Anhui
	The Hefei Light Source is a dedicated VUV and soft X-ray light source. The layout of magnet lattice limits the achievalbe beam emittance and available straight section for insertion device. To enhance competitiveness of National Synchrotron Radiation Laboratory in synchrotron radiation application research region, a concept of new dedicated VUV and soft X-ray synchrotron radiation light source was put forward, which is named Hefei Advanced Light Source. Comparing the advantages, difficulties and performance/foundation of energy recovery linac, linac-based free electron laser and storage ring based light source, the scheme of a 1.5GeV storage ring with very low beam emittance was adopted as the baseline design. At same time, a low emittance 1.5 GeV linac would be as its full-energy injector, which can provide ultra-short radiation pulse. The HALS would provide more brilliant and transverse coherent synchrotron radiation in the VUV and soft X-ray range to various users.

WEPC064	The Possibility of Conversion of Hefei Light Source Storage Ring Into a Dedicated THz Radiation Source	synchrotron, synchrotron-radiation, storage-ring, collective-effects	2139
	L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang USTC/NSRL, Hefei, Anhui
	In the future of National Synchrotron Radiation Laboratory, a new advanced VUV and soft X-ray light source would be contructed and provide synchrotron radiation with high brilliance and transverse coherence. At that time, the current HLS storage ring would be replaced by the new one. Instead of retire of the old ring, there is another case, that is upgrading current low energy storage ring as a dedicated THz light source. In this paper, the possibility of lattice upgrading were evaluated. And its performance was estimated according to exist theoretical model.

WEPC065	The Lattice Design of Hefei Advanced Light Source (HALS) Storage Ring	emittance, insertion, insertion-device, lattice	2142
	L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang USTC/NSRL, Hefei, Anhui
	The purpose of Hefei Advanced Light Source is to provide high brilliant and coherent synchrotron radiation in the VUV and soft X-ray range to synchrotron radiation users. To enhance high brilliance and transverse coherent, very low beam emittance is required. The design goal of beam emittance is lower than 0.2 nmrad, whose synchrotron radiation is fully transverse coherent beyond the 2.5nm. Considering achievable undulator radiation spectrum and energy dependence of emittance, the energy of storage ring is set as 1.5GeV. Limiting the circumference of storage ring, the more dipole and strong focusing are needed for lowering emittance. On the other side, strong chromatic sextupoles are needed to compensate large natural chromaticity. The storage ring became strong nonlinear. The linear optics and nonlinear dynamics of HALS storage ring were introduced in this paper.

WEPC069	A Possible THz Radiation Source with a Train of Short Pulses in the SPARC High Brightness Photoinjector	electron, cathode, simulation, linac	2154
	M. Boscolo, M. Castellano, E. Chiadroni, M. Ferrario, A. Stella, C. Vaccarezza INFN/LNF, Frascati (Roma) V. Petrillo Universita' degli Studi di Milano, Milano
	A radiofrequency electron gun followed by a compressor can generate trains of THz sub-picosecond electron pulses by illuminating the photocathode with a comb laser pulse. This structure of the beam can be used to produce coherent radiation. A feasibility study for a possible experiment at SPARC to be realized with the addition of a dedicated magnetic chicane is discussed. An optimization study of a magnetic chicane with a negative and variable R56 is studied, together with a set of parameters relative to the SPARC machine with the intent of demonstrating the feasibility of this experiment. The dynamics is studied within the SPARC system with the PARMELA code and with the RETAR code for the evaluation of the radiation.

WEPC075	Recent Results and Future Perspectives of the SPARC Project	emittance, undulator, linac, laser	2169
	M. Ferrario, D. Alesini, M. Bellaveglia, R. Boni, M. Boscolo, M. Castellano, E. Chiadroni, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, B. Marchetti, A. Marinelli, C. Marrelli, E. Pace, L. Palumbo, L. Pellegrino, R. Ricci, U. Rotundo, C. Sanelli, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) A. Bacci, I. Boscolo, F. Broggi, F. Castelli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, A. R. Rossi, L. Serafini INFN-Milano, Milano M. Bougeard, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Salieres, O. Tchebakoff CEA, Gif-sur-Yvette L. Catani INFN-Roma II, Roma A. Cianchi Università di Roma II Tor Vergata, Roma F. Ciocci, G. Dattoli, A. Dipace, A. Doria, G. P. Gallerano, L. Giannessi, E. Giovenale, G. L. Orlandi, S. Pagnutti, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I. P. Spassovsky, V. Surrenti ENEA C. R. Frascati, Frascati (Roma) M.-E. Couprie SOLEIL, Gif-sur-Yvette M. Mattioli, M. Serluca INFN-Roma, Roma M. Migliorati, A. Mostacci Rome University La Sapienza, Roma M. Petrarca Università di Roma I La Sapienza, Roma J. B. Rosenzweig UCLA, Los Angeles, California
	The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive 500 nm FEL experiments in various configurations, a Thomson backscattering source and a plasma accelerator experiment. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. As a first stage of the commissioning a complete characterization of the photoinjector has been accomplished with a detailed study of the emittance compensation process downstream the gun-solenoid system and the demonstration of the emittance oscillation in the drift. The second stage of the commissioning, that is currently underway, foresees a detailed analysis of the beam matching with the linac in order to confirm the theoretically prediction of emittance compensation based on the “invariant envelope” matching and the demonstration of the “velocity bunching” technique in the linac. In this paper we report the experimental results obtained so far and the scientific program for the near future.

WEPC076	Remote Tilt-control System of Injection Bump Magnet in the SPring-8 Storage Ring	injection, synchrotron, synchrotron-radiation, coupling	2172
	K. Fukami, C. Mitsuda, M. Oishi, M. Shoji, K. Soutome, H. Yonehara, C. Zhang JASRI/SPring-8, Hyogo-ken M. Hasegawa, T. Nakanishi SES, Hyogo-pref. T. Ohshima RIKEN/SPring-8, Hyogo
	The SPring-8 storage ring has four pulse-bump magnets to generate bump orbit for beam injection. Rotational error of the bump magnets around a beam-axis (tilt) induces the stored-beam oscillation in vertical direction due to horizontal error field. In the top-up operation, vertical perturbation of the stored-beam during beam injection is mainly produced by the tilt. We evaluated the tilt angle by measuring of the perturbation turn-by-turn using a single-pass BPM system and realigned bump magnets manually inside the accelerator tunnel. It was required to repeat the measurement and realignment processes two or three times for convergence. To correct the tilts smoothly, we developed a remote tilt-control system. The system consists of two fixed and one movable supports in vertical direction under each bump magnets. The movable support is driven by a stepper motor through 1/30 worm gear in the range of ±4 mrad with the accuracy of less than 0.1 mrad. By using this system, we succeeded complete on-beam reduction of the perturbation.

WEPC096	APPLE Undulator for PETRA III	dipole, undulator, polarization, emittance	2219
	J. Bahrdt, H.-J. Baecker, W. Frentrup, A. Gaupp, M. Scheer, B. Schulz BESSY GmbH, Berlin U. Englisch, M. Tischer DESY, Hamburg
	Currently, the storage ring PETRA is being rebuilt to a light source with an ultra low emittance of only 1nm rad. The undulator radiation will take full advantage of this high performance. PETRA III will also provide circularly polarized light and linearly polarized light under arbitrary angles (inclined mode) within the energy range of 250-3000eV. The light will be produced with an APPLE II undulator which is under construction at BESSY at present. The total length of 5m and a minimum gap of only 11mm cause strong 3D forces. Due to the small good field region in an APPLE undulator and a small stay clear between the magnets and the vacuum chamber a sophisticated mechanical layout is required. The design will be presented, the expected residual mechanical deformations will be given and the consequences for the spectral performance will be discussed.

WEPC098	Development of Cryogenic Undulator CPMU at SOLEIL	permanent-magnet, undulator, vacuum, cryogenics	2225
	C. Benabderrahmane, P. Berteaud, N. Béchu, M.-E. Couprie, J.-M. Filhol, C. Herbeaux, C. A. Kitegi, J. L. Marlats, A. Mary, K. Tavakoli SOLEIL, Gif-sur-Yvette
	On SOLEIL at 2.75 GeV, producing hard X rays requires short period and small gap in-vacuum hybrid permanent magnet undulators. Besides, higher achieved peak magnetic field can be while operating at cryogenic temperature Tc (around 140 K). When cooling down the permanent magnets, the remanence Br increases down to a certain temperature at which the process is limited by the appearance of the Spin Reorientation Transition phenomenon. The coercivity is also increased at Tc which improves significantly the resistance to radiation. R&D studies, aims at replacing SmCo by NdFeB permanent magnets whose Br of 1.4 T, could enable to increase at least by 30% the peak magnetic field at Tc. Unfortunately such magnet grade can’t be heated to high temperature without degrading the magnetic properties, which limits the residual pressure that can be achieved. Temperature gradient and mechanical deformation are also technical issues. Different permanent magnet grades at Tc are characterized. Studies are also carried out on a small assembly of four periods. Residual pressures obtained with or without partial baking on standard U20 in-vacuum undulators are compared.

WEPC099	A Superconductive Undulator for the Munich Laser-plasma Accelerator	undulator, electron, photon, brilliance	2228
	P. Peiffer, T. Baumbach, A. Bernhard, D. Wollmann University of Karlsruhe, Karlsruhe F. J. Gruener, D. Habs, C. Huebsch, R. Weingartner LMU, München R. Rossmanith FZK, Karlsruhe
	Laser-plasma accelerators are expected to produce electron beams with bunch charges in the nano-Coulomb range with energies in the GeV range. By employing short-period superconductive undulators this may be utilized for the generation of undulator radiation in the X-ray regime with a compact laboratory-sized set up. In this contribution we report on the project of testing this concept at the Laser-Plasma Accelerator in Munich. A particular aim of this project is to push the superconductive undulator technology to shortest periods and highest on-axis fields at gap widths sufficiently large to reduce the impact of resistive wall wake fields on the electron beam. This might open a path to the generation of coherent radiation via the SASE process.

WEPC102	Commissioning of the Electromagnetic Insertion Devices at SOLEIL	undulator, power-supply, insertion, insertion-device	2237
	F. Briquez, P. Brunelle, O. V. Chubar, M.-E. Couprie, J.-M. Filhol, O. Marcouillé, F. Marteau, A. Nadji, L. S. Nadolski, M. Valleau, J. Vétéran SOLEIL, Gif-sur-Yvette
	SOLEIL is the French 2.75 GeV third generation synchrotron radiation light source. Eleven undulators are installed yet in the storage ring and nineteen more Insertion Devices (ID) will be installed on the ring by January 2010. Among the installed IDs, there are four electromagnetic undulators of two different designs: one 640 mm period air coils undulator called HU640 and three 256 mm period undulators called HU256, made up of independent H yoke dipoles. The HU640 provides photons in any polarisation from linear to elliptical, in a range extending from 5 to 40 eV, thanks to three different groups of coils powered independently. The HU256, which are subject to hysteresis, provide horizontal and vertical, periodic or quasi-periodic linear polarisations, and also circular polarisation, covering a total range from 10 eV to 1 keV. The effects of each undulator on the closed orbit have been extensive studied, and compensated, using dedicated embedded steering coils. The correction method will be explained and its results will be shown and compared to the magnetic measurements. Finally, the first measurements of the radiation produced will be shown and compared to previsions.

WEPC106	Compensation of Variable Skew- and Normal quadrupole Focusing Effects of APPLE-II Undulators with Computer-aided Shimming	undulator, quadrupole, insertion, insertion-device	2246
	O. V. Chubar, F. Briquez, M.-E. Couprie, J.-M. Filhol, E. Leroy, F. Marteau, F. Paulin, O. Rudenko SOLEIL, Gif-sur-Yvette
	Variable (phase- and gap-dependent) skew- and normal-quadrupole focusing effects of APPLE II undulators on electron beam are reportedly complicating practical use of this type of insertion devices in many synchrotron radiation sources. We show that these undesirable effects, whatever their "origin", can be well controlled and in many cases efficiently compensated during the standard "virtual" shimming of APPLE-II undulators. Our method exploits small variations of the skew- and normal-quadrupole focusing components resulting from extra magnetic interaction, introduced by displacements of permanent magnet blocks during the shimming procedure, at different undulator phase and gap values. These variations can be calculated to a high accuracy, included into the corresponding "shim signatures" of magnetic field integrals, and used, along with undulator magnetic measurements data, for calculation of the most efficient magnet displacements. This approach is well suited for a computer-aided (e.g., genetic optimization based) shimming procedure. Practical results obtained with several APPLE-II undulators, which are currently successfully operating on the SOLEIL storage ring, are presented.

WEPC112	The Acceptance and Photon Beam Formation in SLS FEMTO Beamline	laser, background, electron, damping	2264
	L. M. Hovhannisyan, D. K. Kalantaryan, V. M. Tsakanov CANDLE, Yerevan S. T. Hakobyan YSU, Yerevan A. Streun PSI, Villigen
	The FEMTO insertion at the Swiss Light Source (SLS) produces sub-ps X-ray pulses by modulating the electron energy in a slice of the bunch through interaction with a fs-laser. The radiation from the sliced bunch in the FEMTO undulator of the SLS storage ring has been studied. Only photons passing all apertures of the beam line arrive at the experiment. We derive the transverse phase space distribution of these photons, the radiation spectra, and the spatial and angular distribution. Transmission of the radiated photons through the FEMTO beamline is calculated using the SRW simulation code in order to evaluate the acceptance of the beamline and the photon beam phase space distribution at the experimental station.

WEPC113	Heat Load Issues of Superconducting Undulator Operated at TPS Storage Ring	undulator, storage-ring, synchrotron, synchrotron-radiation	2267
	C.-S. Hwang, J. C. Jan, P. H. Lin NSRRC, Hsinchu
	The superconducting undulator with periodic length of 1.5 cm and magnet gap of 5.6 mm has been studied. The magnetic flux density of 1.4 T has been achieved. However, the heat loads from image current of the electron in the storage ring and the synchrotron radiation from bending magnet are the critical issues. The calculated power from the image current and the synchrotron radiation of bending magnet are about 3.5 W/m and 1.7 W, respectively. The superconducting undulator will be operated at the 3 GeV TPS storage ring that the operation current and the magnet flux density of dipole magnet is 400 mA and 1.19 T, respectively. The superconducting RF cavity will be installed in the TPS such that the bunch length is only 2.8 mm. Hence, the superconducting Landau cavity is necessary to extend the bunch length for reducing the heat load on the beam duct. In addition, some strategies are needed to be studied to avoid the synchrotron radiation heating on the 4.2 K vacuum chamber. The soft-end dipole design and the chicane mechanism are studied to solve the issue herein.

WEPC114	Improved Winding of Superconducting Undulator and Measurement of Quenching Tolerance	undulator, synchrotron, synchrotron-radiation, storage-ring	2270
	J. C. Jan, C.-H. Chang, C.-S. Hwang, F.-Y. Lin NSRRC, Hsinchu
	The superconducting (SC) wire windings of the mini-pole superconducting undulator at National Synchrotron Radiation Research Center (NSRRC) have an improved performance. A precise measurement of the magnetic field was undertaken to examine the quality of the wire winding. We improved the insulation between wires and the iron pole to avoid SC wire degradation when the coil was trained up to high current. A Teflon coating (layer thickness 0.035-0.045 mm) on the iron pole is capable of providing insulation to 0.5 kV. We pasted extra Teflon tape (thickness 0.12 mm) on the coating layer; this Teflon tape serves as a buffer that avoids the SC wires scraping the Teflon coating layer during adjustment of the position of the SC wire during winding. A quenching experiment was also performed to detect the heat tolerance of the SC wires during extra heating of the beam duct; a heating tape (Ni80Cr20) simulated the heating of the beam duct by synchrotron radiation. The SC wires and heater are separated by the stainless steel (SS) beam duct (thickness 0.3 mm) and an epoxy layer (thickness 0.1 mm). This result is an important issue in cryostat design.

WEPC115	Development of IVUN at Pohang Accelerator Laboratory	undulator, vacuum, electron, insertion-device	2273
	D. E. Kim, H. S. Han, Y. G. Jung, C. K. Kim, H.-G. Lee, S. H. Nam, P. C.D. Park, K.-H. Park, H. S. Suh PAL, Pohang, Kyungbuk
	Pohang Accelerator Laboratory (PAL) is developing In Vacuum Undulator (IVUN). A short magnetic length (about 1.0 m) IVUN with 24 mm magnetic period will be developed first and a longer IVUN with 1.8 m magnetic length which will be installed in the PLS storage ring will follow. The IVUN will be equipped with built-in magnetic measurement system to ensure the accuracy of the assembly, any degradation coming from the radiation damage or high temperature. Basically, a hall probe system will be installed with linear guide to translate the measurement assembly. In this report, the design issues related to the vacuum system, measurement system, and other engineering problems of the IVUN will be discussed.

WEPC118	Study of Controllable Polarization SASE FEL by a Crossed-planar Undulator	undulator, polarization, electron, simulation	2282
	B. Faatz, Y. Li, J. Pflueger, E. Saldin, E. Schneidmiller, M. V. Yurkov DESY, Hamburg
	A potential and economical access to generate arbitrary polarized XFEL is to utilize crossed-undulator scheme instead of helical undulators. In this paper, the polarization of x-ray radiation for the European XFEL is investigated. The degree of polarization and the Stokes parameters are calculated for different configurations. The shot-to-shot fluctuation of polarization and the degree of polarization distribution over the transverse plane are also studied.

WEPC126	On a Biscuit Current Undulator	undulator, electron, laser, wiggler	2303
	S. Sandru UPG, Ploiesti V. Babin INOE, Bucharest M. R. Leonovici Bucharest University, Faculty of Physics, Bucharest-Magurele V. I.R. Niculescu INFLPR, Bucharest - Magurele
	A new undulator structure for free electron lasers was presented. Current BISCUIT devices produce magnetic fields which are spatially periodic. The current structure was in the shape of wires stacks . The current has alternating directions. The magnetic field components for each wire presents symmetry with two axis. The BISCUIT undulator transverse cross-section (in arbitrary units) is a function depending directly on cosine (for x component) and sine (for y component) and inverse on the square root of the sum of forth power of sine and cosine. The z component is a constant. The Biot - Savart law was numerically evaluated. The magnetic field is longitudinal and easily adjustable with the current. The versatility of the constant parameter covers longitudinal undulator or wiggler design for one or two beams devices with transverse momenta.

WEPC128	SPUR: A New Code for the Calculation of Synchrotron Radiation from Very Long Undulator Systems	undulator, electron, synchrotron, synchrotron-radiation	2305
	N. C. Ryder, D. J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire S. Reiche UCLA, Los Angeles, California
	The accurate calculation of synchrotron radiation from an undulator is a common problem and numerous codes have been developed that describe analytic and measured fields. However, for very long undulator systems, comprising of many individual modules and total lengths in excess of 100s of meters, for example as found in the LCLS, X-FEL, the ILC positron source undulator systems, there is not a suitable code that can handle the amount of data in a convenient manner and which runs in a practically realisable time limit. The development of a new code, SPontaneous Undulator Radiation, SPUR, is presented which computes the spontaneous radiation from electron beams passing through a system of undulators. The code supports parallel architecture, and uses the HDF5 technology to efficiently handle the multi-dimensional data. The latest results developments and benchmarking are presented.

WEPC129	Undulator Demagnetization due to Radiation Losses at FLASH	undulator, quadrupole, free-electron-laser, permanent-magnet	2308
	J. Skupin, B. Faatz, Y. Li, J. Pflueger, T. Vielitz DESY, Hamburg
	The free-electron laser FLASH was set up at DESY Hamburg in 2004. It is a high-gain, single pass FEL which operates in the VUV and soft X-ray wavelength regime. To monitor the demagnetization of the undulator structures due to radiation losses a small test undulator was installed. This dosimetric undulator (DU) consists of a short piece of magnetic undulator structure with only 3 pole pairs and corresponding magnets. It is positioned in front of the first undulator module where a high dose rate is to be expected. The accumulated dose of DU and undulator system is derived by weekly measurements with thermoluminescence dosimeters (TLDs). The DU is dismounted and magnetically measured regularly. Based on these measurements a (maximal) relative demagnetization rate of about 510^-4/kGy was derived. In view of this result magnetic measurements on one of the undulators from TTF1 (the predecessor of FLASH) were reviewed. They show a relative demagnetization rate of about 210^-4/kGy which is lower but still in the same range as the result from FLASH. FEL simulations to analyse the influence of the demagnetization on the SASE process are in progress.

WEPC136	Waveguide Structures for RF Undulators with Applications to FELs and Storage Rings	undulator, electron, polarization, storage-ring	2326
	M. Yeddulla, H. G. Geng, Z. Huang, Z. Ma, S. G. Tantawi SLAC, Menlo Park, California
	RF undulators, suggested long time ago, has the advantage of fast dynamic control of polarization, undulator strength and wavelength. However, RF undulators require very strong RF fields in order to produce radiation of the same order as conventional static devices. Very high power RF energy confined inside a waveguide or a cavity can provide the necessary RF fields to undulate the electron beam. However, the wall losses in the waveguide should be low enough to make it practically feasible as a CW or quasi CW undulator and, hence, competitive with static devices for applications to storage rings and FELs. Here we present various waveguide structures such as smooth walled and corrugated walled waveguides and various RF modes. We will show that there are some advantages in operating with higher order modes and also with hybrid modes in the corrugated guide. We will show that the RF power requirement for some of these modes will permit a quasi CW operation of the undulator, thus permitting its operation in a storage ring.

WEPC152	Magnet Block Optimization of the APPLE-II Elliptically Polarized Undulator	polarization, undulator, synchrotron, synchrotron-radiation	2362
	T. Wang, Q. K. Jia USTC/NSRL, Hefei, Anhui
	The uniform field region of elliptically polarized undulator (EPU) of APPLE-II type is very short especially in the horizonta axis. The magnet block arrangements with a approximately parabolic pole face or of APPLE-II undulator can enlarge the horizontal field roll-off and shorten the vertical field roll-off. We studied the dfferent shapes to expect a optimizaed horizotal and vertical field roll-off.

WEPD009	The CERN High Field Magnet Program	dipole, luminosity, quadrupole, insertion	2419
	G. De Rijk CERN, Geneva
	With the LHC, magnets of 10T peak field Nb-Ti technology were developed and this technology reached full maturity. The next step in field level, with a peak field in the range of 15T, will be needed for the LHC phase II upgrade. For this upgrade the temperature margin and radiation resistance of the Nb-Ti coil technology is not sufficient. Begin 2008 CERN starts a program to develop high field magnets for LHC upgrades and other future programs. For this mostly Nb3Sn conductors will be employed but also HTS conductors will be considered. In this paper an overview will be presented of the projects for which this HFM technology will be needed. The the program will be presented in terms of R&D chapters and work packages. The need and opportunities for collaborations with other institutes will be discussed.

WEPD036	Radiation and Thermal Analysis of Superconducting Quadrupoles in the Interaction Region of Linear Collider	quadrupole, extraction, shielding, linear-collider	2488
	A. V. Zlobin, A. I. Drozhdin, V. Kashikhin, V. S. Kashikhin, M. L. Lopes, N. V. Mokhov Fermilab, Batavia, Illinois A. Seryi SLAC, Menlo Park, California
	The upcoming and disrupted electron and positron beams in the baseline design of ILC interaction region are focused by compact FD doublets each consisting of two small-aperture superconducting quadrupoles and multipole correctors. These magnets will work in a severe radiation environment generated primarily by incoherent pairs and radiative Bhabhas. This paper analyzes the radial, azimuthal and longitudinal distributions of radiation heat deposition in incoming and disrupted beam doublets. Operation margins of baseline quadrupoles based on NbTi superconductor and direct wind technology as well as alternative designs based on NbTi or Nb3Sn Rutherford cables are calculated and compared. The possibilities of reducing the heat deposition in magnet coils using internal absorbers are discussed.

WEPD038	Thermal and Structural Modeling of the TTF Cryomodule Cooldown and Comparison with Experimental Data	simulation, cryogenics, controls, monitoring	2494
	S. Barbanotti, P. Pierini INFN/LASA, Segrate (MI) K. Jensch, R. Lange, W. Maschmann DESY, Hamburg
	The study of thermal and structural behavior during cooldown/warmup of long SRF cryostats is important for both the XFEL and ILC, which base the design on the successful TTF design. We present the finite elements analysis of the main internal components of the cryomodules during the transient cooldown and warmup, comparing the data obtained with data taken at DESY on the linac.

WEPP001	Energy Loss of Coasting Gold Ions and Deutrons in RHIC	synchrotron, synchrotron-radiation, ion, impedance	2518
	N. P. Abreu, M. Blaskiewicz, K. A. Brown, J. J. Butler, W. Fischer, M. Harvey, S. Tepikian BNL, Upton, Long Island, New York H. Burkhardt CERN, Geneva
	The total energy loss of coasting gold ion beams was measured at RHIC at two energies, corresponding to a gamma of 75.2 and 107.4. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.

WEPP065	Beam Commissioning of the SPS-to-LHC Transfer Line TI 2	extraction, optics, proton, controls	2668
	J. A. Uythoven, G. Arduini, R. W. Assmann, N. Gilbert, B. Goddard, V. Kain, A. Koschik, T. Kramer, M. Lamont, V. Mertens, S. Redaelli, J. Wenninger CERN, Geneva
	The transfer line for the LHC Ring 1 was successfully commissioned with beam in the autumn of 2007. After extraction from the SPS accelerator and about 2.7 km of new transfer line, the beam arrived at the temporarily installed beam dump, about 50 m before the start of the LHC tunnel, without the need of any beam threading. This paper gives an overview of the hardware commissioning period and the actual beam tests carried out. It summarises the results of the beam test optics measurements and the performance of the installed hardware.

WEPP071	Preliminary Exploratory Study of Different Phase II Collimators	simulation, collimation, luminosity, impedance	2683
	L. Lari, R. W. Assmann, A. Bertarelli, C. Bracco, M. Brugger, F. Cerutti, A. Dallocchio, A. Ferrari, M. Mauri, S. Roesler, L. Sarchiapone, V. Vlachoudis CERN, Geneva J. E. Doyle, L. Keller, S. A. Lundgren, T. W. Markiewicz, J. C. Smith SLAC, Menlo Park, California L. Lari EPFL, Lausanne
	The LHC collimation system is installed and commissioned in different phases, following the natural evolution of the LHC performance. To improve cleaning efficiency towards the end of the low beta squeeze at 7TeV, and in stable physics conditions, it is foreseen to complement the 30 highly robust Phase I secondary collimators with low impedance Phase II collimators. At this stage, their design is not yet finalized. Possible options include metallic collimators, graphite jaws with a movable metallic foil, or collimators with metallic rotating jaws. As part of the evaluation of the different designs, the FLUKA Monte Carlo code is extensively used for calculating energy deposition and studying material damage and activation. This report outlines the simulation approach and defines the critical quantities involved.

WEPP134	Ultra-short x-ray Radiation coming from a Laser Wakefield Accelerator	electron, plasma, laser, betatron	2809
	V. Leurent, L. Divol, T. Doeppner, D. H. Froula, S. H. Glenzer, P. Michel, J. Palastro LLNL, Livermore, California C. E. Clayton, C. Joshi, K. A. Marsh, A. E. Pak, J. E. Ralph, T.-L. Wang UCLA, Los Angeles, California B. B. Pollock, G. R. Tynan UCSD, La Jolla, California
	A Laser Wakefield Accelerator (LWFA) is under development at LLNL Jupiter Laser Facility to produce multi-GeV electron bunches promising to provide a bright and compact source of x-ray radiation for high energy density studies. The interaction of a high power (200 TW), short laser (50 fs) pulse with neutral He gas can accelerate monoenergetic electrons up to 1 GeV in a stable self-guiding regime, over a dephasing length of 1 cm (for a plasma density of 1.5x10¹⁸ cm^-3), overcoming the limitation of vacuum diffraction and allowing long interaction lengths for LWFA. The waveguide can be extended over several centimeters by using a novel scheme, which employs an external magnetic field (up to 5 T uniform along 12 cm) to control the radial heat flux* resulting from the interaction of a high energy (100 J), long pulse (1 ns) laser with a gas tube. The acceleration of electrons over several centimeters can produce multi-GeV bunches and thus a powerful x-ray source. Analysis will be presented on femtosecond x-ray radiation produced by wiggling an electron bunch with energy above 1 GeV in this new LWFA scheme. * W. Lu et al., Phys. Rev. Spec. Top-ac 10, 061301 (2007) ** D. H. Froula et al., Phys. Rev. Lett. 98, 135001 (2007)

WEPP136	Femtosecond and Attosecond Bunches of Electrons upon Field Emission in a Combined Quasi-static and Laser Electric Field	cathode, electron, laser, single-bunch	2812
	V. A. Papadichev LPI, Moscow
	Obtaining short pulses of particles and of electromagnetic radiation is of interest for investigating fast processes in physics, chemistry, biology and medicine,. A new method of modulating an electron beam is proposed to obtain electron bunches of 100-as to 20-fs duration. For this purpose, two electric fields – quasi-static and the variable field of a laser with wavelength in the 0.25 – to 10 microns range – simultaneously act on a single-spiked or multi-spiked cathode. Current from 0.01 to 100 A from one spike having a curvature radius of 1 micron corresponds to a maximal intensity of total electric field of 70 to 280 MV/cm for a 10-micron laser wavelength. For a 1-micron laser, total fields of 300 – 400 MV/cm should be used for 1 – 20 A currents. A regime of device operation was determined for which the emitting surface of a copper cathode is not damaged. Obtaining a single bunch or a sequence of bunches with a repetition rate up to1330 THz was considered. Using multi-spiked cathodes permits to obtain bunches with current up to 10 kA. P. Emma. Issues and challenges for short pulse radiation production, Proc. EPAC04, p. 225, Lucerne, Suisse. **S. Rimjuem et al. Generation of femtosecond electron pulses, Proc. EPAC04, p. 431.

WEPP138	Experimental Demonstration of Ultrashort μJ-Class Pulses in the Terahertz Regime from a Laser Wakefield Accelerator	laser, electron, controls, plasma	2818
	G. R.D. Plateau, C. G.R. Geddes, N. H. Matlis, C. B. Schroeder, C. Toth, J. van Tilborg LBNL, Berkeley, California O. Albert LOA, Palaiseau E. Esarey, W. Leemans University of Nevada, Reno, Reno, Nevada
	Ultrashort terahertz pulses with energies in the μJ range can be generated with laser wakefield accelerators (LWFA), which are novel, compact accelerators that produce ultrashort electron bunches with energies up to 1 GeV* and energy spreads of a few-percent. Laser pulses interacting with a plasma create accelerated electrons which upon exiting the plasma emit terahertz pulses via transition radiation. Because they are only tens of femtoseconds long, electron bunches can radiate coherently (CTR) in a wide bandwidth (~ 1 - 10 THz) yielding terahertz pulses of high intensity,. In addition to providing a non-invasive bunch-length diagnostic*** and thus feedback for the LWFA, these high peak power THz pulses are suitable for high field (MV/cm) pump-probe experiments. Here we present energy-based measurements using a Golay cell and a single-shot electro-optic technique which were used to characterize the full waveform of these μJ-class THz pulses, including phase and amplitude information. W. P. Leemans et al. N. P. 2/696 (2006). W. P. Leemans et al. P. R.L. 91/074802 (2003). C. B. Schroeder et al. P. R.E 69/016501 (2004). **J. van Tilborg et al. P. R.L. 96/014801 (2006).

WEPP151	Metallic Photonic Band Gap Accelerator Structure Experiments and Design	vacuum, damping, electron, insertion	2841
	R. A. Marsh, M. A. Shapiro, R. J. Temkin MIT/PSFC, Cambridge, Massachusetts
	Damping wakefields is a critical issue in the next generation of high gradient accelerators. Photonic bandgap (PBG) structures have unique properties that offer significant wakefield damping. The goal of this work is to quantify the higher order mode (HOM) wakefield content of a constructed metallic PBG accelerator structure, in order to test the theory of wakefield excitation in these structures and to provide direction for future structure design. Experimental measurements of wakefields excited by an 18 MeV electron beam in a 6 cell, 17.14 GHz metallic PBG traveling wave accelerator structure are reported. Because the electron beam used to generate wakefields in the PBG structure is bunched at the 17.14 GHz rf frequency, all wakefields observed were at integer multiples of 17.14 GHz. Using diode detectors, radiation has been observed at the input and output coupler ports as well as through a quartz window in the surrounding vacuum vessel. Estimates of wakefield radiation, made using HFSS and basic wakefield theory, compare well with experiment.

WEPP158	Simulation of beam Halo in CLIC Collimation Systems	simulation, collimation, synchrotron, synchrotron-radiation	2859
	G. A. Blair, S. Malton Royal Holloway, University of London, Surrey I. V. Agapov, A. Latina, D. Schulte CERN, Geneva
	Full simulation of the CLIC and ILC collimation systems are performed to take account of collimator wakefield effects from the core beam on the halo. In addition full simulation of the interaction of the halo with the collimator material is performed to study the effect of multiple scattering and also the production of neutrons in the electromagnetic showers. The effect of beam-gas scattering downstream of the collimators is also included.

WEPP163	Measurements of Collimator Wakefields at End Station A	simulation, feedback, linear-collider, collider	2868
	J.-L. Fernandez-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire S. Molloy SLAC, Menlo Park, California J. D.A. Smith Cockcroft Institute, Warrington, Cheshire N. K. Watson Birmingham University, Birmingham
	The angular kicks imparted to an electron beam with energy of 28.5 GeV when it passes through a collimator jaw with a certain offset, generating a wakefield, were measured in End Station A (ESA) in SLAC for fifteen different collimator configurations of geometry and material. Some configurations were chosen in order to compare with previous measurements while others served to study the effect of geometry and taper angles (geometrical contribution to the wakefield) and the effect of the material resistivity (resistive contribution) to the kick. This paper summarises the final experimental results. The reconstructed kick factor is compared to analytical calculations and simulations.

WEPP168	Mechanical Design of Collimators for the ILC	vacuum, linear-collider, collider, photon	2883
	B. D. Fell, D. Angal-Kalinin, S. C. Appleton, J.-L. Fernandez-Hernando, F. Jackson, O. B. Malyshev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire N. Bliss STFC/DL, Daresbury, Warrington, Cheshire G. Ellwood, R. J.S. Greenhalgh STFC/RAL, Chilton, Didcot, Oxon J. D.A. Smith Cockcroft Institute, Warrington, Cheshire N. K. Watson Birmingham University, Birmingham
	Much attention has been paid to the optimisation of the geometry and material of collimators in the ILC to mitigate the effects of both short-range transverse wakefields and errant beam impacts. We discuss the competing demands imposed by realistic engineering constraints and present a preliminary engineering design for adjustable jaw spoilers for the ILC.

THPPGM04	SLIM - An Early Work Revisited	closed-orbit, coupling, damping, lattice	2963
	A. Chao SLAC, Menlo Park, California
	An early, but at the time illuminating, piece of work on how to deal with a general, linearly coupled accelerator lattice is revisited. This work is based on the SLIM formalism developed in 1979-1981.
	Slides

THPC013	Start to End Simulations of Transverse to Longitudinal Emittance Exchange at the A0 Photoinjector	emittance, simulation, space-charge, synchrotron	3002
	R. P. Fliller, H. T. Edwards, J. Ruan Fermilab, Batavia, Illinois T. W. Koeth Rutgers University, The State University of New Jersey, Piscataway, New Jersey
	Various schemes to exchange the transverse and longitudinal emittance have been proposed (Cornacchia and Emma, Kim et.al). One scheme involves a deflecting mode RF cavity between two doglegs to exchange the horizontal and longitudinal emittances. This will produce a complete and uncoupled emittance exchange in the thin cavity limit using first order matrix optics. Various other effects, such as a finite length cavity, can leave the emittances coupled after the exchange and dilute the final emittances. Other effects such as space charge and synchrotron radiation can only be investigated through simulations. An exchange experiment is underway at the A0 Photoinjector at Fermilab. In this paper we present start to end simulations of the experiment using various codes to account for space charge and Coherent Synchrotron Radiation effects. Astra is used to simulate all of the straight sections, including the deflecting mode RF cavity. CSR track simulates the doglegs, and the spectrometer. The results of these simulations are compared with analytical approximations and preliminary data. The effect on the exchange is also discussed.

THPC014	Investigation of Possible CSR Induced Energy Spread Effects with the A0 Photoinjector Bunch Compressor	simulation, emittance, electron, synchrotron	3005
	R. P. Fliller, H. T. Edwards, G. M. Kazakevich, J. Ruan, R. Thurman-Keup Fermilab, Batavia, Illinois T. W. Koeth Rutgers University, The State University of New Jersey, Piscataway, New Jersey
	The bunch compressor of the A0 Photoinjector at Fermilab was removed this past spring to install a transverse to longitudinal emittance exchange experiment. Prior to its removal questions arose about the possibility of observing the effects of Coherent Synchrotron Radiation on the compressed beam. The energy spread of the beam with and without compression was measured to observe any changes. Various beam charges were used to look for square law effects associated with CSR. No direct observation of CSR was attempted because the design of the vacuum chamber did not allow it. In this paper we report the results of these experiments and comparison with simulations using ASTRA and CSRTrack. The results are compared with analytical approximations. The implications for the ongoing transverse to longitudinal emittance exchange experiment are discussed.

THPC041	Closed Orbit Correction and Orbit Stabilization Control for TPS Storage Ring	quadrupole, emittance, closed-orbit, dipole	3068
	H.-J. Tsai, H.-P. Chang, H. C. Chao, P. J. Chou, K. T. Hsu, C.-C. Kuo, W. T. Liu, J. W. Tsai NSRRC, Hsinchu
	TPS is a 3 GeV synchrotron storage ring proposed in Taiwan. The designed natural emittance with slightly positive dispersion in the straight sections is less than 2 nm-rad. With 1% emittance coupling, the beam size in horizontal and vertical plane are 120/5 micron in the short straight sections, respectively. The beam position stability requirements are 10% of the beam sizes, i.e., 12/0.5 micron in the horizontal/vertical plane. The closed orbit distortions due to alignment displacement and magnetic field errors are simulated. The distribution of beam position monitors and the location of slow and fast correctors are proposed and the level of achievement is shown.

THPC044	Accurate Calculation of Higher Order Momentum Compaction Factor in a Small Ring	storage-ring, sextupole, synchrotron, synchrotron-radiation	3074
	L. Wang, G. Feng, W. Li, L. Liu, C.-F. Wu, H. Xu, S. C. Zhang USTC/NSRL, Hefei, Anhui
	The key issues to obtain short beam bunch in storage ring is to lowering momentum compaction factor. When the linear momentum compaction factor is small, higher order momentum compaction factor can produce significant effects in the longitudinal beam dynamics. In the small storage ring, higher order momentum comaction factor is determined not only by sextupoles, and also by the fringe field of main magnets. In this paper, the higher order momentum factor formula including the effects of fringe field is deduced. As a example, the momentum compaction factor of HLS storage ring was calculated.

THPC091	Experimental Study of an Intense Relativistic Helical Electron Beam Formed with Interception of the Electrons Reflected from the Magnetic Mirror	electron, gun, cathode, space-charge	3200
	E. V. Ilyakov, I. S. Kulagin, S. V. Kuzikov, A. S. Shevchenko IAP/RAS, Nizhny Novgorod V. N. Manuilov NNGU, Nizhny Novgorod
	A new method of formation of pulsed intense relativistic helical electron beams (HEBs) for gyroresonant devices has been presented. The method is aimed at the increase of pitch-factor and the reduction of HEB velocity spread and is intended for use in the formation systems of laminar HEBs characterized by low influence of space charge on their parameters. The method is based on the operation of a special diaphragm located at one of minima of trajectories at the beginning of the transportation channel. The diaphragm diameter is chosen so that the electrons with the lowest oscillatory velocities cannot bend round the diaphragm and settle on it. The rest electrons pass by moving in the increasing magnetic field. Then, the electrons with the greatest oscillatory velocities are adiabatically reflected from the magnetic mirror between the electron gun and the transportation channel and settle on the back of the same diaphragm. Reduction of space charge of the reflected electrons has led to the increase of HEB pitch-factor (HEBs have been formed with the record of pitch-factors exceeding 2), while the accumulation of space charge worsens the HEB provoking modulation of formed HEB current.

THPC108	Observation of Bound States of Particles in the Storage Ring	storage-ring, electron, synchrotron, vacuum	3230
	A. S. Tarasenko, I. S. Guk NSC/KIPT, Kharkov
	The deviation of n-particle state lifetime from the law T1/n, where T1 is a mean lifetime of one particle, in the storage ring was experimentally observed. Authors relate this deviation to interaction between the particles, conditioned by the fields directed in passive resonant devices of vacuum chamber of the storage ring. Depending on type of connection of the beam with passive resonant device, the interaction can be repulsive or attracting. The binding energy of a pair of particles for a case of their effective attraction is calculated.

THPC146	Beam Halo Monitor Using Diamond Detectors for XFEL/SPring-8	electron, induction, undulator, permanent-magnet	3330
	H. Aoyagi, Y. Asano, T. Bizen, K. Fukami, N. Nariyama JASRI/SPring-8, Hyogo-ken T. Itoga, H. Kitamura, T. Tanaka RIKEN/SPring-8, Hyogo
	The construction of the XFEL facility at SPring-8 has been started. We have been developing a halo monitor as an interlock device for protection of undulator permanent magnets against radiation damage. When permanent magnets are irradiated with a halo part of 8GeV electron beam, magnetic fields are degraded permanently and laser oscillation is weakened. Therefore, the interlock device is required during machine operation. Diamond detector, which operates in photoconductive mode, is good candidate for electron beam sensor. The beam test of the diamond detector head has been carried out at the beam dump of the SPring-8 booster synchrotron. Minimum number of injected electron was about 1·10⁵ /pulse, and we observed the pulse height of 0.1V having the pulse length of 0.6nsec FWHM without a preamplifier. The linearity of output signal on injected beam was also demonstrated. The beam halo monitor equipped with the diamond detectors is under manufacturing. The design and feasibility tests will be presented in this conference.

THPC156	Performances of the SPARC Laser and RF Synchronization Systems	laser, linac, klystron, feedback	3354
	A. Gallo, D. Alesini, M. Bellaveglia, G. Gatti, C. Vicario INFN/LNF, Frascati (Roma)
	The SPARC project consists in a 150 MeV S-band, high-brilliance linac followed by 6 undulators for FEL radiation production at 530 nm. The linac assembly has been completed and the SPARC scientific program is presently in progress. The low level RF control electronics to monitor and synchronize the RF phase of the accelerating structures along the linac and the laser shot on the photocathode has been commissioned and it is now fully operative. The laser synchronization is routinely monitored and slow drifts are automatically corrected by a dedicated shot-to-shot feedback system. A similar slow automatic regulation is implemented on each linac accelerating section acting either on low level or high power sliding lines. The phase noise in the 2 RF power stations is counteracted by fast intra-pulse phase feedback systems that have been developed and put in operation. Phase stability measurements taken over the whole synchronization system are reported, and performances of different synchronization architectures, micro-wave based or laser based, are compared.

THPC157	A Simple Method for Timing an XFEL Source to High-power Lasers	undulator, electron, photon, laser	3357
	G. Geloni, E. Saldin, E. Schneidmiller, M. V. Yurkov DESY, Hamburg
	We propose a technique for timing an XFEL to a high-power laser with femtosecond accuracy. The same electron bunch is used to produce an XFEL pulse and an ultrashort optical pulse that are, thus, naturally synchronized. Cross-correlation techniques will yield the relative jitter between the optical pulse (and, thus, the XFEL pulse) and a pulse from an external pump-laser with femtosecond resolution. Technical realization will be based on an optical replica synthesizer (ORS) setup to be installed after the final bunch-compressor. The electron bunch is modulated in the ORS by an external optical laser. Travelling through the main undulator, it produces the XFEL pulse. Then, a powerful optical pulse of coherent edge radiation is generated as the bunch passes through a long straight section and a separation magnet downstream of the main undulator. Relative synchronization of these pulses is preserved using the same mechanical support for X-ray and optical elements transporting radiation to the experimental area, where single-shot cross-correlation between optical pulse and pump-laser pulse is performed. We illustrate our technique with numerical examples referring to the European XFEL.

THPP073	Performance of the SNS Front End and Warm Linac	linac, target, beam-losses, kicker	3530
	A. V. Aleksandrov, C. K. Allen, S. M. Cousineau, V. V. Danilov, J. Galambos, J. A. Holmes, D.-O. Jeon, T. A. Pelaia, M. A. Plum, A. P. Shishlo, M. P. Stockli, Y. Zhang ORNL, Oak Ridge, Tennessee
	The Spallation Neutron Source accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of an H^- injector, capable of producing one-ms-long pulses at 60 Hz repetition rate with 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The 2.5 MeV beam from the Front End is accelerated to 86 MeV in the Drift Tube Linac, then to 185 MeV in a Coupled-Cavity Linac and finally to 1 GeV in the Superconducting Linac. With the completion of beam commissioning, the accelerator complex began operation in June 2006 and beam power is being gradually ramped up toward the design goal. Operational experience with the injector and linac will be presented including chopper performance, longitudinal beam dynamics study, and the results of a beam loss study.

THPP107	Lifetime Comparisons of Single and Double Layered HBC-Foils using 3.2MeV Ne⁺ Ion Beam	ion, vacuum, target, cathode	3617
	I. Sugai, Y. Irie, H. Kawakami, M. Oyaizu, A. Takagi, Y. Takeda KEK, Ibaraki T. Hattori, K. K. Kawasaki RLNR, Tokyo
	The Japan-Proton Accelerator Research Complex (J-PARC) requires thick carbon stripper foils of 300-500 μg/cm² thick to strip electrons from the H-beam supplied by the linac before injection into the RCS. The energy depositions upon foil by the intense circulating proton bunched beam as well as H-beam result in the foil temperature of ~1800K. Thus, conventional carbon stripper foils will rupture in a very short time and even a high quality diamond foil will be broken at around 1800 K. Therfore, thick carbon stripper foils with high durability even at 1800K are indispensable for such accelerators. We have developed HBC (Hybrid type Boron mixed Carbon)-foil. We have measured the lifetime of a double and single-layered HBC-foils, diamond (DM) foils and commercially available carbon (CM) foils for comparisons using 3.2 MeV Ne⁺ ion beam, in which a significant amount of energy loss is deposited in the foils. The lifetime of the double-layered HBC- foil (180 μg/cm² x 2) was found to be long 18 and 446 times longer than those of DM-foil (360μg/cm² x 1) and double-layered CM foils ( 207μg/cm² x 2), respectively.

THPP126	Four Quadrant 60 A, 8 V Power Converters for LHC	dipole, controls, feedback, hadron	3655
	L. Ceccone, V. Montabonnet CERN, Geneva
	The LHC (Large Hadron Collider) particle accelerator requires many true bipolar power converters (752), located under the accelerator dipole magnets in a radioactive environment. A special design and topology is required to obtain the necessary performance while meeting the criteria of radiation tolerance and compact size. This paper describes the ±60A ±8V power converter, designed by CERN to meet these requirements. Design aspects, performances and test results of this converter are presented.

THPP128	Failure Mechanisms of Power Systems in Particle Accelerator Environments and Strategies for Prevention	power-supply, shielding, simulation, proton	3661
	S. Sandler, C. Hymowitz AEI, Los Angeles
	This paper discusses the mechanisms that cause degradation and failure in DC-DC converters destined for high radiation and magnetic field environments, particularly those encountered in accelerators. Failure mechanisms discussed include transformer saturation, loss of PWM control, and power supply turn-off. Degradation mechanisms that produce circuit performance outages include circuit parameter drift in Mosfets due to temperature and Vgsth reduction. Environmentally induced drift of current limit, voltage references, and switching performance are also presented. The author’s background in worst case analysis of Space based power supplies gives them particular insight into the radiation impact, assessment, and mitigation of such phenomenon. A variety of techniques for identifying and reducing the probability of these failures are presented. Methods include analysis based strategies, modified switching timing and control, improved gate drive circuitry, proper component selection, and appropriate shielding. Results are provided for a 3kW supply developed for the LHC at CERN using COTS in an 45kRAD TID, 7.7·10¹² neutron fluence, and 300 Gauss magnetic field environment.

THPP139	Stainless Steel Vacuum Chambers for the SSRF Storage Ring	vacuum, storage-ring, synchrotron, synchrotron-radiation	3688
	D. K. Jiang, Y. L. Chen, Y. Liu, Y. Lu, Y. M. Wen, L. Yin, Z. T. Zhao SINAP, Shanghai G. D. Liu, Z. A. Zheng Shanghai Sanjin Vacuum Equipment Ltd. Company, Shanghai
	Stainless steel 316LN plate was adopted as main material for SSRF storage ring vacuum chambers and ante-chamber structure was used just as other 3rd light source. The analysis for the deformation of the chambers under atmospheric pressure and the thermal situation under synchrotron radiation were done with ANASYS program. Many problems on the structure design and fabrication technique were revealed and suitable solving methods were found in the process of development and manufacture of nine chamber prototypes. Deep draw die was used to form the chambers’ figuration. Wire cutting and CNC machining were used to manufacture the main components. The flatness tolerance, straightness tolerance and the deformation of the chambers under atmospheric pressure were all less than 1mm. After annealed in the vacuum furnace at 850℃, the magnetic permeability of welding seal was reduced from 2.5 to 1.02, the residual stress was deleted, and the vacuum performance was improved. Now SSRF vacuum system is being operated very well. The average pressure without beam is about 2.5×10^-8 Pa and the average pressure with beam of 3GeV/100mA is about 8×10^-7 Pa.

THPP147	NEG Coated Chambers at SOLEIL: Technological Issues and Experimental Results	vacuum, synchrotron, controls, storage-ring	3711
	P. Manini, A. Bonucci, A. Conte, S. Raimondi SAES Getters S.p. A., Lainate N. Béchu, C. Herbeaux SOLEIL, Gif-sur-Yvette
	The SOLEIL accelerator complex includes a 100 MeV LINAC pre-injector, a full energy booster synchrotron and a 2.75 GeV electron storage ring with a 354-meter circumference, which provides synchrotron light to 24 photon beam lines. SOLEIL is the first synchrotron facility specifically designed to make extensive use of Non Evaporable Getter (NEG) coating technology to improve the vacuum, reduce bremsstralhung radiation and boost beam performances. In fact, NEG coating of the straight parts of the vacuum system covers more than 50% of the overall storage ring surface and includes 110 quadrupole and sextupole chambers as well as several conductance limited narrow insertion devices. Use of such a large amount of NEG coated chambers has posed several challenges in term of coating technology, chamber testing, installation and machine commissioning. We report in the present paper main technological issues related to the chambers preparation, film deposition, quality control and characterization. Chambers installation in the main ring, conditioning and activation procedures as well as preliminary vacuum performances will be also discussed.