EPAC08 - List of Keywords (vacuum)

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vacuum

Paper	Title	Other Keywords	Page
MOYCGM01	FAIR: Challenges Overcome and Still to be Met	antiproton, dipole, superconducting-magnet, ion	17
	H. Stöcker GSI, Darmstadt
	FAIR will be one of the leading accelerator facilities worldwide making use of a highly sophisticated and cost-effective accelerator concept. The intensity frontier will be pushed by several orders of magnitude for the primary and especially for the secondary beams. To reach the unprecedented beam parameters several technical challenges such as operation with high brightness, high current beams, control of the dynamic vacuum pressure or the design of rapidly cycling superconducting magnets have to be mastered. For most of those challenges solutions have been found and prototypes are being built. The remaining open questions are addressed in close collaborations with the partners of FAIR.
	Slides

MOZBG01	Vacuum Performances in the Most Recent Third Generation Synchrotron Light Sources	storage-ring, synchrotron, impedance, radiation	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

MOPC040	COBALD - an Inverse Compton Back-scattering Source at Daresbury	laser, electron, photon, beam-transport	160
	D. J. Holder STFC/DL/ASTeC, Daresbury, Warrington, Cheshire D. Laundy STFC/DL, Daresbury, Warrington, Cheshire G. Priebe STFC/DL/SRD, Daresbury, Warrington, Cheshire
	An inverse Compton Back-scattering (CBS) ultra-short pulsed x-ray source driven by the multi-terawatt laser installed at Daresbury’s Energy Recovery Linac Prototype (ERLP) is being developed. Hard x-rays, ranging from 15 keV to 30 keV, depending on the backscattering geometry, will be generated through the interaction of the laser pulse and an electron bunch delivered by ERLP. The X-rays created contain 15 ·10⁶ photons per pulse from head-on collisions, with a pulse duration comparable to that of the incoming electron bunch, and 5 ·10⁶ photons per pulse from side-on collisions, where the laser pulse defines the pulse width. The peak spectral brightness of ≈10²⁰ photons/s/mm²/mrad²/0.1% ΔE/E is close to that of 4th-generation synchrotron light sources. Called COBALD, it will initially be used as a short pulse diagnostic for the ERLP electron beam and will explore the extreme challenges of photon/electron beam synchronization, which is a fundamental requirement for all accelerator-based (whether FEL or spontaneous SR) dynamics programmes. Furthermore, a fast-melting experiment will be used as a diagnostic tool to provide further information on the stability of the source.

MOPC060	Transverse Resistive-wall Wake of a Round Pipe with Finite Thickness and its Effect on the ERL Multi-bunch Beam	impedance, simulation, injection, lattice	202
	N. Nakamura ISSP/SRL, Chiba
	We already started to study the effect of resistive-wall wake on the multi-bunch beam in an ERL (energy recovery linac)-based light source, because resistive-wall beam breakup(RWBBU) could be caused by the cumulative transverse wake generated by interaction between the resistive vacuum pipe and the intense multi-bunch beam. However the resistive-wall wake function of a round pipe used so far for studying the RWBBU was valid only in a limited time range and improper to the RWBBU simulation for a longer time period. Therefore we analytically derived an exact expression of resistive-wall impedance of a round pipe with finite thickness over all the frequency range and numerically calculated the resistive-wall wake functions of several different pipes from the exact impedance expression. The calculated wake functions enabled us to study and simulate the beam behavior in an ERL made of the pipes accurately. We will present the transverse resistive-wall wake of a round pipe with finite thickness and its effect on the ERL multi-bunch beam. N. Nakamura et al., Proceedings of PAC07, Albuquerque, June 2007, pp. 1010-1012.

MOPC072	Photocathode Studies at FLASH	cathode, laser, photon, electron	232
	S. Lederer, S. Schreiber DESY, Hamburg J. H. Han Diamond, Oxfordshire P. M. Michelato, L. Monaco, C. Pagani, D. Sertore INFN/LASA, Segrate (MI)
	Since several years, the DESY photoinjectors at FLASH and PITZ use cesium telluride photocathodes. One concern of operating an electron source with these cathodes is the degradation of the quantum efficiency (QE), starting from about 10 % to below 0.5 % during operation. To further understand this behavior the QE is monitored routinely. In this paper recent results from photocathode studies at FLASH are presented.

MOPC073	Design of an Upgrade to the ALICE Photocathode Electron Gun	electron, gun, cathode, laser	235
	B. L. Militsyn, B. D. Fell, L. B. Jones, J. W. McKenzie, K. J. Middleman STFC/DL/ASTeC, Daresbury, Warrington, Cheshire I. Burrows, R. J. Cash STFC/DL, Daresbury, Warrington, Cheshire S. N. Kosolobov, H. E. Scheibler, A. S. Terekhov ISP, Novosibirsk
	The design of an upgrade to the GaAs photocathode electron gun of the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory is presented. This proposed upgrade includes a reduction of the photocathode diameter from 32 to 10 mm and the installation of a dedicated photocathode preparation system with side loading of the photocathodes. The preparation system forms a united vacuum system with the gun but is separated by a gate valve. This allows for significant improvements to the vacuum conditions in the gun and a reduction of pollution from caesium vapour which improves gun stability under high voltage. This preparation facility will reduce the time taken for photocathode changeover from weeks to hours. The facility should provide photocathodes with higher quantum efficiency due to a more controllable preparation procedure and allows experiments to be performed with photocathodes activated to different levels of electron affinity.

MOPC075	Cs2Te Photocathode Robustness Studies	cathode, gun, ion, emittance	241
	D. Sertore, P. M. Michelato, L. Monaco, C. Pagani INFN/LASA, Segrate (MI) S. Lederer, S. Schreiber DESY, Hamburg F. Stephan DESY Zeuthen, Zeuthen
	Cs2Te photocathodes are used as laser driven electron sources at FLASH and PITZ. Besides many aspects of their performances, their robustness to gas exposition and the effect of pollutants on photocathode properties, and indirectly on the photoemitted electrons, are a field still rather unexplored. In this article we present the results of controlled exposition of Cs2Te photocathodes to gases typical present in the UHV environment of an RF Gun with respect to spectral response (QE vs. wavelength), and QE uniformity. Moreover, a comparison between polluted cathodes and fresh ones during operation in an RF Gun is presented.

MOPC085	High Power Neutron Converter for Low Energy Proton/Deuteron Beams: Liquid Metal Driving System	target, radiation, proton, 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.

MOPC086	IFMIF-EVEDA Accelerator: Beam Dump Design	linac, quadrupole, rfq, shielding	259
	B. Brañas, F. Arranz, G. Barrera, J. M. Gómez, A. Ibarra, D. Iglesias, C. Oliver CIEMAT, Madrid
	The IFMIF-EVEDA accelerator will be a 9 MeV, 125 mA cw deuteron accelerator prototype for verifying the validity of the accelerator design for IFMIF. A beam stop will be used for the RFQ and DTL commissioning as well as for the EVEDA accelerator tests. Therefore, this component must be designed to stop 5 MeV and 9 MeV deuteron beams with a maximum power of 1.12 MW. The first step of the design is the beam-facing material selection. The criteria used for this selection are low neutron production, low activation and good thermomechanical behavior. A thermomechanical analysis with ANSYS has been performed for a few materials which show good behavior from the radiological point of view. The input data are the expected beam shape and divergence at the beam dump entrance produced by the high energy beam line quadrupoles, a conical beam stop shape and the preliminary design of the cooling system. As a conclusion of the previous studies a conceptual design of the beam stop will be presented.

MOPC088	High Power Neutron Converter for Low Energy Proton/Deuteron Beams: Test Facility	target, controls, electron, gun	265
	V. Gubin, A. V. Antoshin, M. S. Avilov, M. F. Blinov, D. Bolkhovityanov, V. A. Golikov, M. A. Kholopov, N. N. Lebedev, P. V. Logachev, V. S. Popov, S. V. Shiyankov, A. S. Tsyganov, I. E. Zhul BINP SB RAS, Novosibirsk
	This paper presents conceptual design of test facility, that is now under creation in the framework of development of high power neutron targets for SPES (INFN-LNL, Italy) and SPIRAL-II (GANIL, France). General destination of facility is to test different target systems and elements (hot converter unit, liquid metal driving gear and cooling systems) as well as experimental checking of supply, protection and control methods etc. Also, this facility must be used as a base for input quality control of targets as a whole in future. The structure, general features and experimental possibilities of facility are described.

MOPC099	Ion Catcher System for the Stabilisation of the Dynamic Pressure in SIS18	ion, beam-losses, electron, controls	295
	C. Omet, H. Kollmus, H. Reich-Sprenger, P. J. Spiller GSI, Darmstadt
	In synchrotrons operated with intermediate charge state heavy ion beams, intensity dependent beam losses have been observed. The origin of these losses is the change of charge state of the beam ions at collisions with residual gas atoms. The resulting m/q deviation from the reference beam ion leads to modified trajectories in dispersive elements, which finally results in beam loss. At the impact on the beam pipe, gas molecules are released by ion stimulated desorption which increase the vacuum pressure locally. In turn, this pressure rise will enhance the charge change- and particle loss process and finally cause significant beam loss within a very short time. In order to suppress and control the gas desorption process, a dedicated ion catcher system incorporating NEG coated surfaces and low-desorption rate materials has been developed and two prototypes were installed in SIS18. The design of the scraper and measured effect on the dynamic residual gas pressure are presented.

MOPC106	Injection and Acceleration of Au³¹⁺ in the BNL AGS	ion, electron, injection, acceleration	313
	W. Fischer, L. Ahrens, K. A. Brown, C. J. Gardner, J. W. Glenn, H. Huang, M. Mapes, J. Morris, V. Schoefer, L. Smart, P. Thieberger, N. Tsoupas, K. L. Unger, K. Zeno, S. Y. Zhang BNL, Upton, Long Island, New York C. Omet, P. J. Spiller GSI, Darmstadt
	Injection and acceleration of ions in a lower charge state reduces space charge effects, and, if further electron stripping is needed, may allow elimination of a stripping stage and the associated beam losses. The former is of interest to the accelerators of the GSI FAIR complex, the latter for BNL RHIC collider operation at energies lower than the current injection energy. Lower charge state ions, however, have a higher likelihood of electron stripping which can lead to dynamic pressures rises and subsequent beam losses. We report on experiments in the AGS where Au³¹⁺ ions were injected and accelerated instead of the normally used Au⁷⁷⁺ ions. Beam intensities and the average pressure in the AGS ring are recorded, and compared with calculations for dynamic pressures and beam losses. The experimental results will be used to benchmark the STRAHLSIM dynamic vacuum code and will be incorporated in the GSI FAIR SIS100 design.

MOPC110	Commissioning of the Heidelberg Cryogenic Trap for Fast Ion Beams (CTF)	cryogenics, ion, radiation, 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.

MOPC114	Status of the Electrostatic and Cryogenic Double Ring DESIREE	ion, storage-ring, electron, proton	331
	P. Löfgren, G. Andler, L. Bagge, M. Björkhage, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, A. Paal, K.-G. Rensfelt, A. Simonsson MSL, Stockholm H. Cederquist, M. Larsson, S. Rosén, H. T. Schmidt Stockholm University, Department of Physics, Stockholm
	DESIREE is a double electrostatic storage ring being built at the Manne Siegbahn Laboratory and Stockholm University. The two rings in DESIREE have the same circumference, 8.7m, and a common straight section along which stored ions can interact. The ion optics for both rings will be housed in a single double walled vacuum chamber built like a cryostat with a radiation screen and several layers of super insulation in between the two chambers. The inner chamber, which holds all the optical elements, will be cooled by four cryogenerators attached to the bottom of this chamber. It is constructed in pure aluminum to ensure good thermal conductivity over the whole structure. The whole accelerator structure will be cooled below 20K. This low temperature in combination with the unique double ring structure will result in a powerful machine for studying interactions between cold molecular ions close to zero relative energy. The outer vacuum chamber is constructed in steel with a high magnetic permeability to provide an efficient screening of the earth magnetic field. DESIREE will be provided with two injectors which will be able to supply both positive and negative ions to both rings.

MOPC122	Experiments with Fe-ion Beam Generation Acceleration and Accumulation in ITEP-TWAC Facility	ion, target, laser, injection	352
	B. Y. Sharkov, P. N. Alekseev, N. N. Alexeev, A. Balabaev, V. I. Nikolaev, V. A. Schegolev, A. Shumshurov, V. P. Zavodov ITEP, Moscow Y. Satov SRC RF TRINITI, Moscow region
	The laser ion source (LIS) developed in collaboration ITEP-TRINITI-CERN with an upgraded version of powerful 100J CO2-laser has been used for Fe-ion beam generation at the input of the pre-injector U-3 delivering separated species of Fe¹⁶⁺ ions with energy of 1.1 MeV/u to booster synchrotron UK for acceleration up to the energy of 160 MeV/u and accumulation in the storage ring U-10 using multiple charge exchange injection technique. First results of Fe-ion beam treating from laser ion source to accumulator ring are presented.

MOPC137	The Cryogenic Storage Ring Project at Heidelberg	ion, cryogenics, storage-ring, electron	394
	R. von Hahn, K. Blaum, J. R. Crespo López-Urrutia, M. W. Froese, M. Grieser, M. Lange, F. Laux, S. Menk, D. Orlov, R. Repnow, C. D. Schroeter, D. Schwalm, T. Sieber, J. Ullrich, J. Varju, A. Wolf MPI-K, Heidelberg H. Quack TU Dresden, Dresden M. Rappaport, D. Zajfman Weizmann Institute of Science, Physics, Rehovot X. Urbain UCL CRC, Louvain-la-Neuve
	At the Max-Planck-Institut für Kernphysik in Heidelberg a next generation electrostatic storage ring at cryogenic temperatures is under development. The main perspective of this unique cryogenic storage ring (CSR) is the research on ions, molecules and clusters up to bio molecules in the energy range of 20 keV -300 keV at low temperatures down to 2 Kelvin. The achievement of this low temperature for all material walls seen by the ions in the storage ring not only causes a strong reduction of black body radiation incident onto the stored particles, but also acts as a large cryopump, expected to achieve a vacuum of better than 1·10^-15 mbar (corresponding to 1·10^-13 mbar room temperature äquivalent). The low temperature and the extreme low vacuum will allow novel experiments to be performed, such as rotational and vibrational state control of molecular ions and their interaction with ultra-low energy electrons and laser radiation. A 20 W at 2 K refrigerator was designed and successfully commissioned. A connection with the fully assembled cryogenic prototype ion trap is under way. In this paper the concept and the status of the cryogenic storage ring will be presented.

MOPC146	Development of Piezoelectric Pulse Gas Valve for Small ECR Ion Source	ion, plasma, ion-source, extraction	418
	M. Ichikawa, H. Fujisawa, Y. Iwashita, Y. Tajima, H. Tongu, M. Yamada Kyoto ICR, Uji, Kyoto
	In a conventional ion source, the source gas is continuously fed even in its pulse operation. This requires a high load to a vacuum pumping system. The situation is prominent when the gas load is relatively higher in such a high current ion source. In order to improve this situation, we try to supply gas only when it is needed by synchronizing the gas feed with the extraction of the ion beam. We have developed a small pulse-gas-valve using a commercially available disc-shape piezoelectric element. This valve is small enough to be mounted in our ECR ion source and is capable of very fast open-and-close operation of an order of kHz repetition. A small ECR ion source with this valve will be presented.

MOPC148	Target Life Time of Laser Ion Source for Low Charge State Ion Production	target, laser, ion, ion-source	424
	T. Kanesue Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka M. Okamura BNL, Upton, Long Island, New York J. Tamura Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
	Laser ion source produces ions by irradiating pulsed laser shots onto the solid state target. For the low charge state ion production, laser spot diameter on the target can be over several millimeters using the high power laser such as Nd:YAG laser (532 nm wave length, 0.82 J / 6 ns). In this case, damages to the target surface is small while there is a visible crater in case of the best focused laser shot (laser spot diameter can be several tens of micrometers) for high charge state ion production. Because damage to the target surface is small, target is not required to be moved to use fresh surface after each laser shot to stabilize plasma. In this paper, the results of target life time measurements will be shown.

MOPC156	ECR Ion Source for the KEK All-ion Accelerator	ion, extraction, simulation, plasma	442
	H. Suzuki, Y. Arakida, T. Iwashita, M. Kawai, T. Kono, K. Takayama KEK, Ibaraki S. I. Inagaki Kyushu University K. Okazaki Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture
	R&D works to realize an all-ion accelerator (AIA)* -capable of accelerating all ions of any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS*, are going on. As an ion source for the KEK-AIA, an electron cyclotron resonance (ECR) ion source has been developed. Permanent magnets made of NdFeB to generate a cusp field and 9.4 GHz microwave to energize plasma electrons have been employed. The microwave power of 750 W generated in a traveling wave tube is focused into the interaction region with a horn antenna. Regarding the cut off density for 9.4 GHz, the vacuum and the gas feeding system has been designed. The base pressure of 1·10^-5 Pa is reached with a single turbo molecular pump of 300 l/min, and the gas flow rate less than 1 cc/min is maintained with a mass flow controller. The plasma chamber is water-cooled against Joule heating. The geometry of the extraction electrodes and the downstream transport line have been optimized by IGUN simulations. The whole system will be embedded in the high voltage terminal box of 200 kV. Details of the design and the preliminary test will be described at this conference. K. Takayama, Y. Arakida, T. Iwashita, Y. Shimosaki, T. Dixit, and K. Torikai, J. of Appl. Phys. 101, 063304 (2007). **K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).

MOPD001	SRF Capabilities at ACCEL in view of ILC/XFEL	diagnostics	445
	M. Pekeler, S. Bauer, M. Peiniger, H. Vogel, P. vom Stein ACCEL, Bergisch Gladbach
	In the last decade, ACCEL has manufactured a variety of prototype SRF cavities but also more than 100 TESLA shape 1.3 GHz 9 cell cavities and more than 100 SNS 805 MHz 6-cell cavities. For the ILC R&D at FNAL, we have delivered 12 ILC 9-cell 1.3 GHz cavities and are currently producing 12 additional such cavities. ACCEL is prepared for the industrial production of cavities, couplers and also the module assembly for the XFEL. We have internally evaluated the needs and costs for an in house production of the XFEL cavities. Within an industrial study we have analysed the coupler production for the XFEL, developed a series production adapted XFEL coupler design based on the TTF-III coupler and determined the costs for the series production. ACCEL participated also in a module assembly study and investigated the costs for manpower and infrastructure to manufacture the needed modules for the XFEL within the forseen time of three years. Last year ACCEL was contracted by DESY to built up an industrial plant for electropolishing 1.3 GHz 9 cell cavities. This plant is in routine operation since November 2007 and we have sucessfully electropolished the first series of 10 cavities for DESY.

MOPD002	Fabrication of ILC Prototype Cavities at Advanced Energy Systems, Inc.	controls, target, site, cryogenics	448
	A. J. Favale, M. D. Cole, E. Peterson, J. Rathke AES, Medford, NY
	Advanced Energy Systems, Inc. has recently completed manufacture of four standard 9-cell TESLA-style ILC cavities, six single-cell ILC prototype cavities, six 9-cell symmetric ILC cavities, and one 9-cell re-entrant cavity of the Cornell design. This paper will present an overview of these fabrication projects and of the evolution of AES capability in cavity manufacturing. To date four of the 9-cell ILC cavities have been tested, the six single-cell cavities have been tested, and the 9-cell reentrant cavity has been tested. Preliminary results will be shown.

MOPD003	ILC Cavity Fabrication Optimization for High Production	factory, electron, radio-frequency, linear-collider	451
	A. J. Favale, M. Calderaro, E. Peterson, J. J. Sredniawski AES, Medford, NY
	In 2006, AES performed a US based industrial Cost Study of RF units in production quantities sufficient for the ILC. During this study detailed costs were estimated for the fabrication steps of the SRF cavities in high production quantities. In late 2007, AES carried out a more detailed study specifically oriented toward optimizing the high production methods of only the SRF cavities to arrive at a best estimate of cost. We have found that the revised estimate shows a 34% reduction in cavity fabrication cost. We have optimized many of the machining and welding steps to take advantage of automated operations were possible. Our high production cost estimates were based upon actual machining, welding and parts handling times derived during the prototype fabrication of ILC type cavities at AES. These values were then applied with learning as appropriate to more automated operations to reduce labor costs. In addition, the type and size of e-beam welding machines was optimized. We found that the use of all single chamber welders covering three specific sizes was most cost effective. Details of steps leading to the stated conclusions are presented herein.

MOPD004	CPI RF Components for the ILC	klystron, electron, gun, controls	454
	T. A. Treado, S. J. Einarson, T. W. Habermann CPI, Beverley, Massachusetts
	Communications & Power Industries, Inc. (CPI) has active programs to refine key components for the European XFEL. These components, the fundamental power coupler and the multibeam klystron (MBK) are also suited for the International Linear Collider (ILC). CPI power couplers are manufactured to our customer's specifications using processes which are standard to the electron device industry as well as processes which are specific to power couplers. We have developed the capability of plating high-RRR copper on stainless steel. We have developed the capability of applying TiN coatings to ceramic windows. Both processes are done in-house under carefully controlled conditions. Both processes have been fully qualified. CPI has manufactured nearly 100 power couplers of various designs. Our presentation will focus on power couplers for the XFEL and the ILC. CPI is currently developing a second-generation, horizontal MBK for DESY. This MBK operates at 10 MW, at an RF frequency of 1.3 GHz, 1.5 ms pulse length, and 10 Hz pulse repetition rate. Our presentation will provide an update on this development program.

MOPD005	Recent Activities in ILC R&D at Hitachi	superconducting-RF, cryogenics, radiation, 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.

MOPD007	Waveguide Directional Couplers for High Vacuum Applications	coupling, controls, ion	460
	H. Downs, P. G. Matthews, W. W. Sanborn Mega Industries, LLC, Gorham
	Directional couplers have always been critical elements in the RF feed systems for accelerator structures. Until now, however, such devices have been confined to areas outside of the high vacuum cavity feeds. The level control of the RF signal required at the cavity inputs is continually increasing and it has become apparent that a directional coupler design for the high vacuum side of the system is necessary. The following paper highlights a novel coupler design to allow high vacuum directional couplers to be realized. Results are presented for both electrical and mechanical characteristics for an L-band device.

MOPD014	First Test Results of ILC/STF Cryogenic System at KEK	cryogenics, superconducting-RF, booster, linear-collider	472
	S. Kaneda, T. Ichitani Taiyo Nippon Sanso Corporation, Kawasaki-city Kanagawa Pref. K. Hara, K. Hosoyama, A. Kabe, Y. Kojima, H. Nakai, K. Nakanishi KEK, Ibaraki T. Kanekiyo Hitachi Technologies and Services Co., Ltd., Kandatsu, Tsuchiura M. Noguchi Mayekawa MFG. Co., Ltd., Moriya S. Sakuma, K. Suzuki Taiyo Nippon Sanso Higashikanto Corporation, Hitachi-city, Ibaraki-Pref J. Yoshida Hitachi Plant Technologies, Ltd., Tokyo
	The STF (Superconducting RF Test Facility) cryogenic system, of which capacity is 30W at 2.0K, has been constructed and commissioned for testing STF cryomodule. In the first operation phase, the STF cryogenic system was successfully cooled down to maintain a superconducting RF cavity at the working temperature of 2.0K. Presented in this session will be the results of the first operation of the cryogenic system and the future collaboration plan among KEK and Japanese cryogenic industrial members.

MOPD019	Construction and Quality Control of Synchrotron SOLEIL Beam Position Monitors	controls, simulation, synchrotron, impedance	487
	E. Cenni, M. Canetti, F. Gangini RIAL VACUUM S.p. A, Parma J. L. Billaud Saint-Gobain C. R.E. E., Cavaillon L. Cassinari, J.-C. Denard, C. Herbeaux SOLEIL, Gif-sur-Yvette
	SOLEIL is a third generation synchrotron light source located near Paris. Due to the high performance required for SOLEIL’s diagnostics, a special production procedure was tailored. During the production of 131 Beam Position Monitors (BPM) more than 500 feedthroughs were inspected; all of them passed strict tests at different stages of the production: Leak test (< 10^-10 mbar l/s), Dimensional control (Displacement <0.050 mm), Vacuum test (Specific Outgassing < 10^-12 mbar l/s cm², Residual Gas Analysis) and Electrical test (Capacitance measure ~8pF, Insulation >50 MΩ, Impedance <0.1 Ω). All the established procedures and tests have been performed in a tight partnership that was more than a simple contractual framework, in which an intensive collaboration led to a knowledge transfer between SOLEIL and Rial Vacuum. The result has been a high percentage of success (few feedthroughs over 500 were replaced) during preliminary tests and a deeper knowledge of “BPM problem solving”; in this article are presented different test procedures to obtain high quality and high performance BPMs.

MOPD028	Radio Frequency Power Sources for the Muon Ionisation Cooling Experiment	power-supply, cathode, controls, monitoring	508
	J. F. Orrett, P. A. Corlett, A. J. Moss, J. H.P. Rogers STFC/DL/ASTeC, Daresbury, Warrington, Cheshire C. J. White STFC/DL, Daresbury, Warrington, Cheshire
	For any future Neutrino Factory the accelerator aperture will be a major cost driver. Potentially the aperture can be reduced and significant capital savings made if ionisation cooling is utilised on the muon beam. In order to demonstrate the effectiveness of ionisation cooling a demonstrator needs to be built and operated. MICE, the Muon Ionisation Cooling Experiment is that demonstrator. The RF requirements of MICE will be met using high power vacuum tube based RF circuits donated by LBNL and CERN. This paper will discuss these circuits, their refurbishment, the construction of HT power supplies and ancillary equipment and high power testing.

MOPD035	20 MW Pulse Amplifier Klystron with Multiple Frequency Two-Gap Bunching Resonators for Linear Electron Accelerators	klystron, electron, bunching, focusing	529
	K. G. Simonov, A. N. Korolev, A. V. Mamontov ISTOK, Moscow Region
	A klystron design with a two-gap bunching resonator which provides interaction with electron beam by fields of multiple frequencies of two-gap resonator fundamental oscillations for increasing the klystron efficiency is being considered. At that the two-gap resonator is tuned to antiphased oscillation at operating frequency and to in-phase oscillation at the second harmonic. Such choice of frequency oscillation types allows to make the resonator compact and provide optimal conditions for electron beam interaction with microwave fields of the two-gap resonator both in antiphased and in-phase oscillation types. The relations for choosing two-gap resonator interaction area size providing a stable klystron operation without self-excitation are given. The compactness of the realized two-gap resonator with multiple frequencies allowed to locate it into klystron drift tube between the main resonators without increasing the klystron overall dimensions. The results of experimental research of klystron with such a two-gap resonator showed a possibility to increase its efficiency significantly.

MOPP008	Design of the Photon Collimators for the ILC Positron Helical Undulator	photon, undulator, positron, electron	565
	A. Bungau UMAN, Manchester I. R. Bailey, J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva Liverpool University, Science Faculty, Liverpool E. Baynham, T. W. Bradshaw, F. S. Carr, J. Rochford STFC/RAL/ASTeC, Chilton, Didcot, Oxon A. J. Brummitt, A. J. Lintern STFC/RAL, Chilton, Didcot, Oxon J. A. Clarke, O. B. Malyshev, N. C. Ryder, D. J. Scott STFC/DL/ASTeC, Daresbury, Warrington, Cheshire N. A. Collomb STFC/DL, Daresbury, Warrington, Cheshire A. F. Hartin OXFORDphysics, Oxford, Oxon S. Hesselbach, G. A. Moortgat-Pick Durham University, Durham L. Zang Cockcroft Institute, Warrington, Cheshire
	A number of photon collimators are placed inside the helical undulator to protect the cold surfaces of the vacuum vessel from being hit by the photons and thus achieving the baseline pressure requirement. Computer simulations were run in order to determine the energy deposition and instantaneous temperature rise in these collimators and various material candidates were studied. This paper presents the status of the simulation.

MOPP012	DC Breakdown Experiments for CLIC	collider, linear-collider, RF-structure, cathode	577
	A. Descoeudres, S. Calatroni, M. Taborelli CERN, Geneva
	For the production of the Compact Linear Collider (CLIC) RF structures, a material capable of sustaining high electric field, with a low breakdown rate and showing low damages after breakdowns is needed. A DC breakdown study is underway at CERN in order to test candidate materials and surface preparations, and also to have a better understanding of the breakdown mechanism. The saturated breakdown fields of several metals and alloys have been measured, ranging from 100MV/m for Al to 900MV/m for stainless steel, being around 150MV/m for Cu, CuZr and Glidcop, 300MV/m for W, 400MV/m for Mo, Nb and Cr, 650MV/m for V, and 750MV/m for Ti for example. Titanium shows a strong material displacement after breakdowns, while Cu, Mo and stainless steel are more stable. The conditioning speed of Mo can be significantly improved by removing oxides at the surface with a heat treatment, typically at 875°C for 2 hours. DC breakdown rate measurements have been done with Cu and Mo electrodes, showing similar results as in RF experiments: the breakdown probability seems to exponentially increase with the applied field.

MOPP022	Transatlantic Transport of Fermilab 3.9 GHZ Cryomodule for TTF/FLASH to DESY	alignment, acceleration, laser, survey	592
	M. McGee, V. T. Bocean, J. Grimm, W. Schappert Fermilab, Batavia, Illinois
	In an exchange of technology agreement, Fermilab built and will deliver a 3.9 GHz (3rd harmonic) cryomodule to DESY to be installed in the TTF/FLASH beamline. This cryomodule delivery will involve a combination of flatbed air ride truck and commercial aircraft transport to Hamburg Germany. A description of the isolation and damping systems that maintain alignment during transport and protect fragile components is provided. Initially, transport and corresponding alignment stability studies were performed in order to assess the risk associated with transatlantic travel of a fully assembled cryomodule. Shock loads were applied to the cryomodule by using a coldmass mockup to prevent subjecting actual critical components (such as the cavities and input couplers) to excessive forces. Accumulative and peak shock loads were applied through over-the-road testing and using a pendulum hammer apparatus, respectively. Finite Element Analysis (FEA) studies were implemented to define location of instrumentation for transport studies and provide modal frequencies and shapes. Shock and vibration measurement results of transport studies and stabilization techniques are discussed.

MOPP023	Test of Short Period SC Undulator	undulator, positron, electron, radiation	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.

MOPP028	Technical Specification for the CLIC Two-Beam Module	quadrupole, alignment, linac, lattice	607
	G. Riddone, H. Mainaud Durand, D. Schulte, I. Syratchev, W. Wuensch, R. Zennaro CERN, Geneva R. Nousiainen HIP, University of Helsinki A. Samoshkin JINR, Dubna, Moscow Region
	The 2-m long CLIC module comprises four decelerating structures and two quadrupoles forming a FODO cell. Each decelerating structure powers two accelerating structures. Some accelerating structures are removed at regular intervals to liberate space for a quadrupole of a FODO lattice. The present layout of the standard and special modules is presented as well as the status of the system integration. The main requirements for the different sub-systems (alignment, supporting, stabilization, cooling and vacuum) are introduced together with the major integration constraints. For the key components the specification on pre-alignment and beam-based alignment tolerances is also recalled as well as their influence on the requirements of other sub-systems. For example the required stable thermal behavior and the tight tolerances of accelerating structure (the requirements for the accelerating structure pre-alignment is 0.014 mm at 1? ) in the CLIC linac largely directly the sizing and integration of the cooling system. The paper also covers the main issues related to the module integration in the tunnel. In the last part, the critical issues and future activities are summarized.

MOPP048	Fast Ion Instability in the CLIC Transfer Line and Main Linac	ion, linac, electron, emittance	655
	G. Rumolo, D. Schulte CERN, Geneva
	The Fast Ion Instability is believed to be a serious danger for bunch trains propagating in the CLIC electron transfer line and main linac, since it may strongly affect the bunches in the tail of the train if the vacuum pressure is not below a certain threshold. We have developed the FASTION code, which can track electrons through a FODO cell line and takes into account their interactions with the produced (and possibly trapped) ions. We describe how this tool can be used for setting tolerances on the vacuum pressure and for giving specifications for the design of a feedback system.

MOPP056	Beam Coupling Impedance in the ILC Damping Rings	impedance, insertion, damping, coupling	670
	M. Korostelev, O. B. Malyshev, A. Wolski Cockcroft Institute, Warrington, Cheshire A. F. Grant, J. Lucas STFC/DL, Daresbury, Warrington, Cheshire
	The ILC damping rings have stringent specifications for beam quality and stability. To avoid instabilities, the various components in the vacuum chamber will need to be carefully designed to minimize the longitudinal and transverse wake fields. We present the results of impedance calculations for various components that are expected to make a significant contribution to the overall machine impedance.

MOPP057	ILC DR Vacuum Design and E-cloud	electron, photon, positron, dipole	673
	O. B. Malyshev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire W. Bruns WBFB, Berlin
	An electron cloud parameters and vacuum design are tightly bounded to each other. Input parameters for the e-cloud depend on shape of vacuum chamber and surface property (material, roughthness, coatings, etc.), electron multipacting in the vacuum chamber causes the electron stimulated gas desorption and may require modification of vacuum system to deal with it. This paper describes the e-cloud modelling performed in a way to optimise ILC DR vacuum design in positron ring and to have clear understanding what modification in vacuum chamber are required. Three parameters of e-cloud were varied in turn: photo-electron emission, secondary electron yield and gas pressure. It was found all three parameter should not exceed certain value to keep the e-cloud density to an acceptable level. The energy and intensity of electron bombardment of the vacuum chamber walls and electron stimulated gas desorption were also calculated. It was found that electron stimulated gas desorption is comparable or larger than the photon stimulated desorption and should be considered in vacuum design.

MOPP063	A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders	electron, dipole, resonance, simulation	688
	M. T.F. Pivi, D. Arnett, F. D. Cooper, D. Kharakh, F. King, R. E. Kirby, B. Kuekan, J. J. Lipari, M. Munro, J. S.T. Ng, J. Olszewski, T. O. Raubenheimer, J. Seeman, B. Smith, C. M. Spencer, L. Wang, W. Wittmer SLAC, Menlo Park, California C. M. Celata, M. A. Furman LBNL, Berkeley, California
	Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders such as ILC and CLIC. Possible remedies for the electron cloud effect include thin-film coatings, surface conditioning, antechamber, clearing electrodes, and chamber with grooves or slots. The effect is expected to be particularly severe in magnetic field regions. To test this and possible mitigation methods, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER). We have also installed test chambers in straight field free regions. The associated chamber consists of bare aluminum and TiN-coated inner surface sections. Each section is instrumented with arrays of readout electrodes and retarding grids. Installation of a grooved chamber is also planned. In this paper, we describe the ongoing R&D effort at SLAC to reduce the electron cloud effect in linear colliders. We present the design of the chicane, the chambers and diagnostics, as well as the experimental results obtained.

MOPP064	Secondary Electron Yield Measurements and Groove Chambers Update Tests in the PEP-II Beam Line	electron, simulation, storage-ring, positron	691
	M. T.F. Pivi, F. King, R. E. Kirby, T. W. Markiewicz, T. O. Raubenheimer, J. Seeman, L. Wang SLAC, Menlo Park, California
	In the Low Energy Ring (LER) of the PEP-II accelerator, we have installed vacuum chambers with rectangular grooves in straight sections to test this possible mitigation technique for the electron cloud effect in the positron damping ring (DR) of the future Linear Colliders such as ILC and CLIC. We have also installed chambers to monitor the secondary electron yield (SEY) of TiN, TiZrV (NEG) and technical accelerator materials under the effect of electron and photon conditioning in situ. Furthermore, we have also installed test chambers in a new 4-magnet chicane. We describe the ongoing R&D effort to mitigate the electron cloud effect in the ILC damping ring, the chambers installation in the PEP-II and latest results.

MOPP065	Microwave Transmission Measurement of the Electron Cloud Density in the Positron Ring of PEP-II	electron, dipole, plasma, simulation	694
	M. T.F. Pivi, A. Krasnykh SLAC, Menlo Park, California J. M. Byrd, S. De Santis, K. G. Sonnad LBNL, Berkeley, California F. Caspers, T. Kroyer, F. Roncarolo CERN, Geneva
	Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation of these machines at high currents. Because of the size of these accelerators, it is difficult to probe the low energy electron clouds over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave which is independently excited and transmitted over a section of the accelerator. We infer the absolute phase shift with relatively high accuracy from the phase modulation of the transmission due to the modulation of the electron cloud density from a gap in the positively charged beam. We have used this technique for the first time to measure the average electron cloud density over a 50 m straight section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center. We have also measured the variation of the density by using low field solenoid magnets to control the electrons.

MOPP066	Recent Experimental Study of Fast Ion Instability in ATF Damping Ring	ion, emittance, damping, single-bunch	697
	N. Terunuma, Y. Honda, T. Naito, J. Urakawa KEK, Ibaraki Eckhard. Elsen, G. X. Xia DESY, Hamburg
	The Fast Ion Instability (FII) is one of the very high priorities of the damping ring R&D for the International Linear Collider (ILC). The Accelerator Test Facility (ATF) in KEK can provide an ILC damping ring-like beam. A specific FII study in ATF has been launched to characterize this phenomenon for the ILC damping ring. A new gas inlet system has been installed recently in the ATF damping ring to control the ion effect. After N2 gas injection into the vacuum chamber in south straight section of the ring, FII has been observed for elevated gas pressures. Beam size blow-up and emittance growth for various fill patterns are presented in this paper and attributed to FII. Comparison between experimental data and simulation results are given as well.

MOPP070	Construction of a Full Scale Superconducting Undulator Module for the International Linear Collider Positron Source	undulator, positron, photon, electron	709
	J. A. Clarke, O. B. Malyshev, D. J. Scott, B. J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire I. R. Bailey, J. B. Dainton, K. M. Hock, L. J. Jenner, L. I. Malysheva, L. Zang Liverpool University, Science Faculty, Liverpool E. Baynham, T. W. Bradshaw, A. J. Brummitt, F. S. Carr, A. J. Lintern, J. Rochford STFC/RAL, Chilton, Didcot, Oxon A. Bungau UMAN, Manchester N. A. Collomb STFC/DL, Daresbury, Warrington, Cheshire A. F. Hartin OXFORDphysics, Oxford, Oxon S. Hesselbach, G. A. Moortgat-Pick Durham University, Durham Y. Ivanyushenkov ANL, Argonne, Illinois N. C. Ryder University of Bristol, Bristol
	The positron source for the ILC is dependent upon a >200m long undulator to generate a high flux of multi-MeV photons. The undulator system is broken down into a series of 4m cryomodules, which each contain two superconducting helical undulators. Following a dedicated R&D phase and the construction and measurement of a number of short prototypes a full scale cryomodule has now been completed for the first time. This paper reports on the design, manufacture, and test results of this cryomodule.

MOPP081	Engineering Design of a PETS Tank Prototype for CTF3 Test Beam Line	beam-losses, alignment, controls, damping	739
	D. Carrillo, L. García-Tabarés, J. L. Gutierrez, I. Rodriguez, E. Rodríguez García, S. Sanz, F. Toral CIEMAT, Madrid G. Arnau-Izquierdo, N. C. Chritin, S. Doebert, G. Riddone, I. Syratchev, M. Taborelli CERN, Geneva J. Calero CEDEX, Madrid
	In the CLIC concept, PETS (Power Extraction and Transfer Structure) role is to decelerate the drive beam and transfer RF power to the main beam. One of the CTF3 test beam line (TBL) aims is to study the decelerated beam stability and evaluate PETS performance. The PETS core is made of eight 800 mm long copper rods, with very tight tolerances for shape (± 20 micron), roughness (less than 0.4 micron) and alignment (± 0.1 mm). Indeed, they are the most challenging components of the tank. This paper reports about the methods of fabrication and control quality of these bars. A special test bench has been designed and manufactured to check the rod geometry by measuring the RF fields with an electric probe. Other parts of the PETS tank are the power extractor, the waveguides and the vacuum tank itself. Industry is partially involved in the prototype development, as the series production consists of 15 additional units, and some concepts could be even applicable to series production of CLIC modules

MOPP083	Status of High Power Tests of Normal Conducting Single-cell Structures	impedance, klystron, damping, electron	742
	V. A. Dolgashev, S. G. Tantawi SLAC, Menlo Park, California Y. Higashi, T. Higo KEK, Ibaraki
	We report results of ongoing high power tests of single cell traveling wave and standing wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the gradient potential of normal-conducting, rf powered particle beam accelerators. The test setup consists of reusable mode launchers and short test structures and powered by SLAC’s XL-4 klystron. The mode launchers and structures were manufactured at SLAC and KEK and tested in SLAC klystron test laboratory. V. A. Dolgashev, S. G. Tantawi, et al. “High Power Tests of Normal Conducting Single Cell Structures,” SLAC-PUB-12956, PAC07, Albuquerque, New Mexico, 25-29 June 2007, pp 2430-2432.

MOPP086	A Novel Fabrication Technique for the Production of RF Photoinjectors	gun, electron, controls, coupling	751
	P. Frigola, R. B. Agustsson, S. Boucher, A. Y. Murokh RadiaBeam, Los Angeles D. Cormier, T. Mahale NCSU, Raleigh L. Faillace Rome University La Sapienza, Roma J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California
	Recent developments in Direct Metal Free Form Fabrication (DMFFF) technology may make it possible to design and produce near netshape copper structures for the next generation of very high duty factor, high gradient radio frequency (RF) photoinjectors. RF and thermal-management optimized geometries could be fully realized without the usual constraints and compromises of conventional machining techniques. A photoinjector design incorporating DMFFF and results from an initial material feasibility study will be reported.

MOPP090	Incorporating RF into a Muon Helical Cooling Channel	lattice, emittance, quadrupole, simulation	760
	S. A. Kahn, M. Alsharo'a, R. P. Johnson Muons, Inc, Batavia D. R. Broemmelsiek, A. Jansson, V. Kashikhin, V. S. Kashikhin, A. L. Klebaner, G. F. Kuznetsov, G. V. Romanov, A. V. Shemyakin, D. Sun, K. Yonehara, A. V. Zlobin Fermilab, Batavia, Illinois L. Thorndahl CERN, Geneva
	A helical cooling channel (HCC) consisting of a pressurized gas absorber imbedded in a magnetic channel that provides solenoidal, helical dipole and helical quadrupole fields has shown considerable promise in providing six-dimensional cooling for muon beams. The energy lost by muons traversing the gas absorber needs to be replaced by inserting RF cavities into the lattice. Replacing the substantial muon energy losses using RF cavities with reasonable gradients will require a significant fraction of the channel length be devoted to RF. However, to provide the maximum phase space cooling and minimal muon losses, the helical channel should have a short period and length. In this paper we shall examine three approaches to include RF cavities into the HCC lattice: Use higher frequency cavities that can be placed inside the magnetic channel, Interleave cavities between magnetic coil rings, and Place banks of RF cavities between segments of HCC channels. Each of these approaches has positive and negative features that need to be evaluated in selecting the proper concept for including RF into the HCC system.

MOPP091	Upgrade of Input Power Coupling System for the SNS RFQ	rfq, coupling, linac, klystron	763
	Y. W. Kang, A. V. Aleksandrov, P. E. Gibson, T. W. Hardek, C. Luck, R. C. Peglow, A. V. Vassioutchenko ORNL, Oak Ridge, Tennessee
	A RF input power coupler system has been developed for upgrade of input coupling to the RFQ in the SNS linac front-end. The design employs two coaxial loop couplers for 402.5 MHz operation. Two couplers are used in parallel to power the accelerating structure with up to 800 kW total peak power at 8% duty cycle. Each coupler loop has a coaxial ceramic window that is connected to each output of a magic-T waveguide hybrid splitter through a coaxial to waveguide transition. The coaxial loop couplers have been designed, manufactured, and high power processed. This paper presents the following: RF and mechanical designs of the couplers and system, procedure and result of high power RF conditioning, and test and operation results of the upgraded system.

MOPP094	Reduction of Q-loss-effects in Ferrite-loaded Cavities	damping, synchrotron, resonance	772
	H. G. Koenig, S. Schaefer GSI, Darmstadt
	Accelerating cavities loaded with Ni-Zn ferrites have been widely used in synchrotrons for many years. So far their performance is significantly limited by the so-called high-loss-effect (HLE) or quality-loss-effect (QLE). After some milliseconds, this effect leads to a sudden drop of the resonator's voltage namely under the following conditions: fixed frequencies with RF-power above a specific threshold level and a parallel DC-biasing. The mechanism of this unwanted loss has not been fully understood yet. Now a simple method has been found to work against this effect with the aid of mechanical damping of surface waves. For small samples of ferrites the QLE is fully suppressed by using a rubber belt around the circumference or by covering the surface with a thin layer of hot-melt adhesive. We were able to show that similar methods applied to full size rings lead to a significant increase of the onset voltage of the QLE. Most of the existing ferrite loaded accelerating cavities with QLE-limitations can be increased in their accelerating voltage by the above-mentioned modification.

MOPP095	Advanced Experimental Techniques for RF and DC Breakdown Research	plasma, electron, simulation, ion	775
	J. W. Kovermann RWTH, Aachen S. Calatroni, A. Descoeudres, T. Lefevre, W. Wuensch CERN, Geneva
	Advanced experimental techniques are being developed to do in-situ analysis of DC and RF breakdowns. First measurements with a specially built spectrometer have been made with a DC spark setup at CERN and with CLIC accelerating structures in the 30GHz power test facility. This spectrometer measures the light intensity development during a breakdown for narrow wavelength intervals in the visible and near infrared range which will give information about the involved elements, temperature and plasma parameters and eventually precursors of a breakdown. Planned experiments for X-ray spectroscopy and imaging, measurements of RF-signals and ion and electron energy distribution and infrared imaging of breakdown sites are presented.

MOPP097	Measurements on the Rf Cavity for the ALBA Storage Ring	impedance, coupling, storage-ring, pick-up	781
	M. L. Langlois, M. Cornelis, F. Pérez, P. Sanchez ALBA, Bellaterra
	ALBA storage ring will use 6 ambient temperature nose cone HOM damped cavities tuned at 500 MHz, designed at BESSY and known as the EU cavity. A first one, manufactured by ACCEL, was delivered in 2007 to investigate on its behaviour. This paper describes the data collected during investigation. First, bead-pull measurements were performed to assess impedance, both on fundamental and high order modes. Emphasis was put on E011, due to the discrepancy between expected values and results for this mode. The vacuum bake-out and related pressure are shown. Then, the cavity was conditioned and observations were made on multipacting levels, conditioning time and surface temperatures. The latter were found inhomogeneous and leads are detailed to avoid local overheating.

MOPP098	A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment	coupling, impedance, emittance, focusing	784
	D. Li, A. J. DeMello, S. P. Virostek, M. S. Zisman LBNL, Berkeley, California R. A. Rimmer Jefferson Lab, Newport News, Virginia
	MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beam’s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

MOPP102	High Field Gradient RF System for a Spiral FFAG, RACCAM	impedance, acceleration, extraction, injection	793
	C. Ohmori KEK, Ibaraki J. Fourrier, J. Pasternak LPSC, Grenoble F. Meot CEA, Gif-sur-Yvette
	A high field-gradient RF system for a spiral FFAG is described. It is wideband to cover the frequency of 3 to 7.5 MHz. The beam will be accelerated with a high repletion rate of 100 Hz to fit requirements for hadron therapy. The cavity has a wide aperture of 90 cm in horizontal direction to allow a large excursion for beam acceleration. It has less than 40 cm in length to fit a very short straight section.

MOPP105	Compact, Tunable RF Cavities	booster, proton, synchrotron, controls	802
	M. Popovic, C. M. Ankenbrandt, E. Griffin, A. Moretti, R. E. Tomlin Fermilab, Batavia, Illinois M. Alsharo'a, I. B. Enchevich, R. P. Johnson, S. Korenev Muons, Inc, Batavia
	New developments in the design of fixed-field alternating gradient (FFAG) synchrotrons have sparked interest in their use as rapid-cycling, high intensity accelerators of ions, protons, muons, and electrons. Potential applications include proton drivers for neutron or muon production, rapid muon accelerators, electron accelerators for synchrotron light sources, and medical accelerators of protons and light ions for cancer therapy. Compact RF cavities that tune rapidly over various frequency ranges are needed to provide the acceleration in FFAG lattices. An innovative design of a compact RF cavity that uses orthogonally biased ferrite for fast frequency tuning and liquid dielectric to adjust the frequency range is being developed using physical prototypes and computer models.

MOPP114	Design of the Prototypical Cryomodule for the EUROTRANS Superconducting Linac for Nuclear Waste Transmutation	cryogenics, linac, radiation, 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.

MOPP117	First Test of the Cornell Single-cavity Horizontal Cryomodule	linac, cryogenics, radiation, 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.

MOPP123	Design and Fabrication of the Cornell ERL Injector Cryomodule	linac, insertion, alignment, shielding	844
	E. P. Chojnacki, S. A. Belomestnykh, Z. A. Conway, J. J. Kaufman, M. Liepe, V. Medjidzade, D. Meidlinger, H. Padamsee, P. Quigley, J. Sears, V. D. Shemelin, V. Veshcherevich CLASSE, Ithaca
	The Energy Recovery Linac (ERL) development effort at Cornell will first produce an ERL beam source. The source will consist of a DC photo-gun, a buncher cavity, beam optics, and then an SRF Injector cryomodule to accelerate the 33-100 mA cw beam from 0.3-0.5 MeV to 5-15 MeV. The Injector cryomodule is based on TTF III technology with modifications to allow cw operation and the flexibility to accommodate the wide range of beam currents, bunch lengths, and beam energy. To deliver the 0.5 MWCW average power to the beam, the Injector cryomodule will contain five SRF 2-cell cavities, each cavity having two 50 kWCW coax couplers to deliver power from 100 kWCW klystrons, of which there are five for the Injector. Both the couplers and klystrons have been tested with 30% overhead in performance. Cold beamline HOM loads are placed between each cavity and outboard of the first and last cavities. Details of the Injector cryomodule design will be presented along with insight gained from the fabrication process, which will benefit the future ERL Linac cryomodule design and proto-typing.

MOPP124	Commissioning of the 400 MHz LHC RF System	klystron, feedback, controls, cryogenics	847
	E. Ciapala, L. Arnaudon, P. Baudrenghien, O. Brunner, A. Butterworth, T. P.R. Linnecar, P. Maesen, J. C. Molendijk, E. Montesinos, D. Valuch, F. Weierud CERN, Geneva
	The installation of the 400 MHz superconducting RF system in LHC is finished and commissioning is under way. The final RF system comprises four cryomodules each with four cavities in the LHC tunnel. Also underground in an adjacent cavern shielded from the main tunnel are the sixteen 300 kW klystron RF power sources with their high voltage bunkers, two Faraday cages containing RF feedback and beam control electronics, and racks containing all the slow controls. The system and the experience gained during commissioning will be described. In particular, results from conditioning the cavities and their movable main power couplers and the setting up of the low level RF feedbacks will be presented.

MOPP127	Commissioning of Superconducting Linac at IUAC - Initial Challenges and Solutions	linac, acceleration, damping, scattering	856
	S. Ghosh, S. Babu, J. Chacko, A. Choudhury, G. K. Chowdhury, T. S. Datta, D. Kanjilal, S. Kar, M. Kumar, A. Mandal, D. S. Mathuria, R. S. Meena, R. Mehta, K. K. Mistri, A. Pandey, P. Patra, P. N. Prakash, A. Rai, A. Roy, B. K. Sahu, S. S. Sonti, J. Zacharias IUAC, New Delhi
	During initial acceleration of ion beam through the first module of linac having eight superconducting (SC) niobium quarter wave resonators (QWR), energy gains were found to be much lower. Major problem encountered was limitation of accelerating fields in the QWR achieved at much higher RF power (up to 300 W) leading to cable melting, metal coating on SC surface and increased cryogenic losses. Cold leaks in the niobium-stainless steel transition assemblies and niobium tuner bellows also posed a major challenge. A novel way of damping mechanical vibration was implemented to reduce RF power. Cooling was improved by installing a hemispherical structure on the resonator. The drive coupler was redesigned to eliminate metal coating. Design of the tuner/transition flange assemblies was modified to avoid cold leak. After incorporation of these modifications, on-line beam acceleration through Linac was accomplished. Pulsed (1.3 ns) Silicon beam of 130 MeV from Pelletron accelerator was further bunched to 250 ps by SC Superbuncher. After acceleration through the linac module and subsequent re-bunching using SC Rebuncher, 158 MeV Silicon beam having pulse width of 400 ps was delivered.

MOPP130	SRF Technology-Past, Present and Future Options	superconductivity, electron, controls, radio-frequency	865
	G. Myneni, M. Hutton Jefferson Lab, Newport News, Virginia
	Superconducting radiofrequency cavities for all recent projects (CEBAF, SNS, KEKB, and TTF) have been built from high purity polycrystalline niobium with a residual resistance ratio (RRR) greater than 250. The procedures and processes used from the initial production of the high RRR polycrystalline niobium sheets to the finished cavities are complex, numerous and very expensive, and the yield of SRF cavities meeting the performance specifications is very low. CBMM – Jefferson Lab invented the large grain and single crystal niobium technologies, and the use of niobium sliced directly from the ingots is expected to change the SRF technology outlook with fewer, and more streamlined, production processes that will not only be cost effective but also generate high yield. In this paper we will show that less stringent commercial niobium specifications are required, and explore the processes and procedures that will lay the foundation for producing SRF cavities with good quality factors at high peak magnetic fields in order to make this technology friendlier for future scientific and technological applications.

MOPP137	MultiPac 2.1 - Multipacting Simulation Package with a 2D FEM Field Solver for a Microsoft Windows System	electron, simulation, RF-structure, superconductivity	880
	Y. M. Li, S. An, Y.-S. Cho, L. Zhang KAERI, Daejon P. Ylä-Oijala Helsinki University of Technology, Helsinki
	MultiPac 2.1 is a multipacting simulation package for analyzing electron multipacting in axisymmetric RF structures with TM_0nl mode, such as RF cavities, coaxial input couplers and ceramic windows. The original package was written by P. Ylä-Oijala, and works with MATLAB 5.0 or 6.0 on Linux operating system. In order to use this code easily for Microsoft Windows customers, we have transferred the MultiPac 2.1 from the Linux system to the Microsoft Windows system. The revised MultiPac can work with Microsoft Windows MatLab 6.0 or later editions smoothly. In this paper, the installation and operation of the Windows MutiPac 2.1 have been introduced. This work was supported by the 21C Frontier R&D program in Ministry of Science and Technology of the Korean Government.

MOPP144	The First Cool-down Tests of the 6 Meter-Long-Cryomodules for Superconducting RF Test Facility (STF) at KEK	superconducting-RF, cryogenics, linear-collider, collider	892
	N. Ohuchi, F. Furuta, K. Hara, H. Hayano, N. Higashi, Y. Higashi, H. Hisamatsu, K. Hosoyama, E. Kako, Y. Kojima, M. Masuzawa, H. Matsumoto, H. Nakai, S. Noguchi, T. Saeki, K. Saito, T. Shishido, A. Terashima, N. Toge, K. Tsuchiya, K. Yokoya KEK, Ibaraki M. H. Tsai NSRRC, Hsinchu Q. J. Xu IHEP Beijing, Beijing
	KEK is presently constructing the Superconducting RF Test Facility (STF) as the center of the ILC-R&D in Asia from 2005. In this project, KEK aims to get the manufacturing and operational experiences of the RF cavity and cryomodule toward the ILC, and two cryomodules have been developed. These cryomodules are 6 meter long and have 4 nine-cell cavities in each cryostat. The basic cross section designs of the cryomodules are almost same as the design of TESLA type-III, however, each cryostat has the different type of cavities, TESLA type and Low-Loss type. The tests for the cryomodules are planed to be performed at three steps. In the first test, measurements of the cryogenic performances of these cryomodules are the main objective. One nine-cell cavity was assembled in each cryostat and the cool-down of the two cryomodules was performed. In the following tests, the four nine-cell cavities will be assembled in each cryostat as the complete integration and the beam test will be performed. In this paper, we will report the design of the cryomodules and the cryogenic performances at the first cold test.

MOPP146	The Coaxial Tuner for ILCTA_NML at Fermilab	cryogenics, superconductivity, linear-collider, collider	895
	A. Bosotti, C. Pagani, N. Panzeri, R. Paparella INFN/LASA, Segrate (MI)
	The piezo Blade Tuner prototype has been successfully tested inside the horizontal cryostat, CHECHIA, at DESY and extensive tests at BESSY are planned. As suggested by the cold test results, a few minor modifications have been implemented and a set of 8 improved devices is under construction for the installation in the second module of ILCTA at Fermilab. This reviewed design, together with a simplified helium tank in prototyping, should hopefully fulfill also the XFEL requests in term of performances and cost. In particular the use of thicker blades and their slightly different distribution along the circumference produces the increase of the tuner strength and stiffness that is needed in order to fulfill the pressure vessel regulations for qualification. As in the past, two equivalent devices, respectively in titanium and stainless steel, have been designed to maintain open the possibility of the use of a SS helium vessel once the required technology were developed. The results of the extensive mechanical tests performed to validate the estimated performances and life time are also presented.

MOPP156	Fabrication and Low Power Testing of an L-band Deflecting Cavity for Emittance-exchange at ANL	coupling, simulation, polarization, emittance	916
	J. Shi, H. Chen, W.-H. Huang, C.-X. Tang, D. Tong TUB, Beijing W. Gai, C.-J. Jing, K.-J. Kim, J. G. Power ANL, Argonne, Illinois D. Li LBNL, Berkeley, California
	An L-Band RF deflecting cavity has been built at Tsinghua University for a planned transverse-to-longitudinal emittance exchange experiment at Argonne National Laboratory (ANL). The deflector is a 1.3-GHz, 3-cell cavity operated in a TM110-like mode that delivers a deflecting voltage of 3.4 MV. In this paper, we review the cavity design and present detail of the fabrication, cold testing and tuning progress. Cell radii were left undercut to account for simulation errors, which yielded a higher frequency in the first bench measurement but removed by the final tuning on the lathe. Field distribution on axis was measured using the ‘‘bead-pull'' method and tuned to balance in the 3 cells.

MOPP162	Titanium Nitride Coating of RF Ceramic Windows by Reactive DC Magnetron Sputtering	lattice, target, electron, controls	931
	V. Variola, H. Jenhani, W. Kaabi, P. Lepercq LAL, Orsay G. Keppel, V. Palmieri, F. Strada INFN/LNL, Legnaro, Padova
	Alumina is a common material for RF windows. Besides its high dielectric strength, it is stable under thermal treatment and has a low out-gassing rate. Nevertheless it has a high secondary electron emission (SEE) coefficient, which leads to multipactor limiting the achievable RF power. One way to suppress the multipactor on RF windows is to coat it with a low SEE-thin TiN film. In the frame of the LAL coupler program a sputtering bench has been developed. It is equipped with two magnetrons and titanium targets. A special rotating holder was designed to allow uniform deposition on cylindrical windows. RF etching of the substrate as a pre-treatment step is allowed, in order to remove particle contamination and to increase TiN adhesion. The TiN sputtering needs the optimisation of gas and electrical parameters. XRD analysis was performed to check the film composition and stoechiometry. The results show how to control the N2 vacancy acting on the gas flow. In addiction, the coating thickness must be optimized not to cause excessive ohmic heating, so multipactor thresholds measurements were done for different coating thickness. Thickness measurments showed a good uniformity.

MOPP165	FZJ Smallest SC Triple-Spoke Cavity	coupling, cryogenics, simulation, site	937
	E. Zaplatin, W. Braeutigam, M. Pap, M. Skrobucha FZJ, Jülich P. Kneisel Jefferson Lab, Newport News, Virginia
	The paper describes the design, fabrication and test results of the smallest triple-spoke cavity (resonant frequency 760 MHz, β=0.2) developed at Forschungszentrum Juelich.

MOPP166	Control System for a PEFP FPC Baking System	controls, monitoring, proton, superconductivity	940
	L. Zhang, S. An, Y.-S. Cho, Y. M. Li, Y. Z. Tang KAERI, Daejon
	In order to bake PEFP Fundamental Power Couplers (FPC) before their RF conditioning, a PEFP baking system has been designed. A control system for the baking system has been completed by using the Labview 8.2 and A-B SLC-500 PLC. In this paper, the server and client communication technology based on OLE for a Process Control (OPC) and a Labview 8.2 Datalogging and Supervisory Control (DSC) Module are described. The program for the SLC-500 PLC with four I/O modules has been written. The mechanical design and control process are described.

MOPP168	Tests on the 1.3 GHz Low Loss Single-Cell RF Superconducting Large Grain Cavities of IHEP	linear-collider, cryogenics, linac, collider	943
	Z. G. Zong, J. Gao, M. Q. Ge, J. Gu, H. Sun, D. Wang, Q. J. Xu, J. Y. Zhai, F. C. Zhao IHEP Beijing, Beijing F. Furuta, T. Saeki, K. Saito KEK, Ibaraki L. Q. Liu Technical Institute of Physics and Chemistry, Beijing L.-Y. Xiong, L. Zhang, T. X. Zhao, Z. G. Zong TIPC, BeiJing
	To contribute to the International Linear Collider (ILC) R&D on the 1.3 GHz low loss cavities has been carried out at IHEP since 2005. Six cavities had been fabricated by the standard technology and treated by some procedures of surface treatments, such as centrifugal barrel polishing, barrel chemical polishing, annealing, high pressure rinsing and baking at in-house IHEP. Because of the shortage of liquid helium in Beijing two large grain cavities with a fine grain one were sent to KEK for vertical tests. The large grain cavities was tested and treated at KEk and finally both reached the accelerating gradients of more than 35 MV/m with the maximum of 40.27 MV/m. This paper presents the testing and results of the large grain cavities.

TUXG01	Last Year of PEP-II B-Factory Operation	luminosity, feedback, injection, controls	946
	J. Seeman SLAC, Menlo Park, California
	The PEP II B-Factory at SLAC has been in operation for a decade, delivering luminosity to the BABAR experiment. The design luminosity was successfully reached after one year of operation and since then it has surpassed over four times design at 1.2 x 10³⁴ cm^-2sec^-1. History of main achievements, high current operation issues, and lessons for the future factories will be presented.
	Slides

TUOAG01	VEPP-2000 Electron-Positron Collider Commissioning and First Results of Round Colliding Beam Tests	electron, injection, lattice, radiation	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

TUOAG02	Commissioning of BEPCII	luminosity, injection, optics, electron	959
	J. Q. Wang, L. Ma, C. Zhang IHEP Beijing, Beijing
	BEPCII is the upgrade project of Beijing Electron Positron Collider (BEPC), serving continuously for both high energy physics experiment and light soure use. As an e⁺-e^- collider, BEPCII will operate in the beam energy region of 1-2.1 GeV with design luminosity of 1*10³³cm^-2s^-1 at 1.89 GeV. The beam commissioning of BEPCII storage rings started out in Nov. 2006. From Nov. 2006 to Aug. 2007, the phase one commissioning was carried out successfully with the so called backup scheme adopting conventional magnets in the IR intead of the superconducting insertion magnets (SIM). After the SIM was intalled into the interaction region, phase two commissioning began in Oct. 2007. The tuning method for high luminosity but low background was extensively studied during phase two, and the beam current has reached more than 1/3 of the design of 0.91 A. The third phase of beam commissioning is planned in May this year after the detector is moved into the on-line position. It is expected that the luminosity would reach to about 30% of its design specification. This paper describes the procedure of beam commissioning of BEPCII and focuses on results of its second phase.
	Slides

TUOCM03	Beam Loss Position Monitoring with Optical Fibres at DELTA	radiation, beam-losses, injection, storage-ring	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

TUPC022	Non-destructive Beam Position and Profile Measurements Using Light Emitted by Residual Gas in a Cyclotron Beam Line	proton, cyclotron, diagnostics, controls	1095
	J. Dietrich FZJ, Jülich C. Boehme UniDo/IBS, Dortmund A. H. Botha, J. L. Conradie, M. A. Crombie, J. H. Du Toit, D. T. Fourie, H. W. Mostert, P. F. Rohwer, P. A. van Schalkwyk iThemba LABS, Somerset West T. Weis DELTA, Dortmund
	Non-destructive beam position and profile measurements were made in the transfer beam line between an 8 MeV solid-pole injector cyclotron and a 200 MeV separated-sector cyclotron that is used for nuclear physics research, radioisotope production and proton and neutron therapy. Light emitted from the beam induced ionization of residual gas particles was measured using a multi-cathode photomultiplier tube (PMT). The PMT was mounted outside the vacuum system on a diagnostic chamber and light passing through a glas window was focused on the photocathode array by means of a lens. The anode currents of the PMT were measured with computer-controlled electronic equipment recently developed for measuring the currents of multi-wire beam profile monitors. Software was developed to control the measurement processes, remove offset values and further process the data digitally. The measured beam positions and profiles were compared with those determined with a multi-wire beam profile monitor for a 3.14 MeV proton beam. It was necessary to shield the PMT from gamma rays generated on nearby slits. The design of the measuring equipment is discussed and the results of the measurements are presented.

TUPC028	Design and Construction of an Inductive Pick-up for Beam Position Monitoring in the TBL Line of the CTF3	pick-up, linac, electron, monitoring	1110
	J. J. Garcia-Garrigos, J. V. Civera-Navarrete, A. Faus-Golfe IFIC (CSIC-UV), Valencia
	In order to determine the beam position respect to the vacuum chamber, the IPU senses the azimuthal distribution of the beam image current flowing along its inner wall when a high frequency bunched beam passes through. The inner wall of the pick-up is divided into four electrodes, each of which forms the primary winding of a toroidal transformer. Therefore the beam image current component flowing through each electrode is transformed to a secondary winding connected to a pick-up output. The closer the beam is to the transformer electrode, the greater is the induced signal in its secondary winding. This basic sensing mechanism will allow to determine the beam position through the four transformers distributed orthogonally around the vacuum pipe. The bandwidth of the IPU and the amplifier is set above 200 MHz to let pass, with low distortion, the 20-140 ns pulse train signal induced from the beam. Also, its expected resolution at maximum current is 5μm. This paper reports on the design, construction as well as testing and calibration processes of two IPU prototypes. They will be installed in the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN by Spring 2008.

TUPC035	The Beam Position Monitor System of the J-PARC RCS	injection, controls, linac, pick-up	1128
	N. Hayashi, S. Hiroki, R. Saeki, K. Satou, R. Toyokawa, K. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken D. A. Arakawa, S. Hiramatsu, M. Tejima KEK, Ibaraki S. Lee, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken
	The Beam Position Monitor (BPM) system of the J-PARC RCS has been fabricated, installed and operated successfully during the beam commissioning. There are 54 BPMs around the ring and most of them are placed inside steering magnets. The BPM is electro static type and it has four electrodes. A pair of electrode gives a linear response with diagonal cut shape and they were calibrated before their installation. The signal processing unit, which is equipped with 14-bit 14MSPS ADC and 600MHz DSP, has been developed for the system. In order to measure small signal, especially during the initial phase of the commissioning, careful design also done for cabling. The paper presents the current performance of the system.

TUPC037	Development, Production and Testing of 4500 Beam Loss Monitors	radiation, 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.

TUPC039	p-Carbon CNI Polarimetry in the AGS and RHIC	polarization, target, scattering, proton	1140
	H. Huang, A. Bazilevsky, A. Bravar, G. Bunce, V. Dharmawardane, R. L. Gill, Y. Makdisi, B. Morozov, M. Sivertz, D. Steski, K. Yip, A. Zelenski BNL, Upton, Long Island, New York I. G. Alekseev, D. Svirida ITEP, Moscow W. Lozowski IUCF, Bloomington, Indiana
	Polarimetry based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region has been utilized for Relativistic Heavy Ion Collider (RHIC). They have been critical tools for polarized proton acceleration setup and provided polarization values for RHIC experiments. This paper summarizes the recent modifications to the hardware and electronics. The performance of the polarimeters is also discussed.

TUPC043	Towards Sub-micrometer Resolution of Single Bunch Strip Line BPM	pick-up, feedback, coupling, simulation	1152
	A. Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
	A high resolution single bunch BPM set-up is designed based on a strip line pickup. One of the BPM modifications developed is a Difference-Sum BPM. In this BPM, each strip line signal is converted into a three 600MHz square wave burst in a cascaded irregular strip line coupler. The Difference and Sum bursts produced by a hybrid junction are detected in a pair of synchronous detectors. The synchronous detector reference signals, and single-sample ADC triggers are manufactured from the Sum burst. The set-up and features of this BPM are presented. The BPM resolution was measured using a KEK ATF beam. For a bunch intensity above 10⁹ electrons the resolution is about 1 μm (for BPM effective aperture 1/5). With appropriate ADCs, this BPM can measure individual bunches at a rate of up to 50 MHz. The BPM latency to the ADC inputs is as low as 10 ns. High resolution and low latency together, make this BPM suitable for beam-based fast feedback/feed-forward systems.

TUPC046	Study on Longitudinal Phase-space of High-brightness Electron Beams at ISIR, Osaka University	electron, photon, linac, radiation	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, radiation, 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.

TUPC050	A Complete Solution for Beam Loss Monitoring	beam-losses, monitoring, controls, injection	1170
	M. Kobal, J. Dedic, R. Stefanic Cosylab, Ljubljana J. F. Bergoz BERGOZ Instrumentation, Saint Genis Pouilly
	In particle accelerator facilities knowing the beam loss is crucial for the machine to be running at optimal efficiency. Beam loss can be monitored on different time scales. Time scale of seconds is used at normal operation to detect any irregularities such as changes in the beta function or vacuum drop. Time scale of 1 ms is used to optimize injection, and 1 μs timescale in case of severe problems when the beam does not live for more than a couple of turns. The presented beam loss system (microIOC-BLM) uses Bergoz BLM sensors, Beam loss Signal Conditioner (BSC) for data acquisition and microIOC-CosyIcon as the central processing unit. The system is cost effective, portable and can be expanded with additional measuring points. Selectable counting interval from 100 μs to 10 s covers a large part of the required time scales. The minimum and maximum count rates are limited by the sensor between 1/s to 10 M./s. Trigger and gate signals are supported as is summing over a number of measurements.

TUPC055	Operating MCP Detectors at Cryogenic Temperatures	cryogenics, electron, storage-ring, ion	1179
	K.-U. Kuehnel, C. D. Schroeter, J. Ullrich MPI-K, Heidelberg
	At present, a low energy electrostatic storage ring operating at cryogenic temperatures down to 2 K is being build up at the MPI-K in Heidelberg. Both, beam diagnostics and experiments rely on the use of position sensitive micro-channel plate (MCP) detectors equipped with phosphor screens or delay line anodes. Since little is known about the performance of these detector types in a cryogenic environment a test chamber was built to investigate their properties. A delay line MCP detector was successfully tested at temperatures as low as 25 K. In this contribution the detailed results of theses tests as well as possible applications of the detector are presented.

TUPC058	Laser-based Ion Beam Diagnostics for the Front End Test Stand at RAL	laser, electron, ion, background	1188
	D. A. Lee, J. K. Pozimski Imperial College of Science and Technology, Department of Physics, London C. Gabor STFC/RAL/ASTeC, Chilton, Didcot, Oxon
	The RAL Front End Test Stand is being constructed to demonstrate that a chopped H^- beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality as required for future high-power proton accelerators can be produced. Because of the high beam power and a preference for online beam monitoring non-intrusive, non-destructive beam diagnostics are desirable. Two novel instruments, based on the photo-detachment of the outer electron of the H^- ions with a laser, are being developed to precisely determine the transverse beam density distribution and the beam emittance at full beam power. This paper discusses the proposed experimental layout of the devices and the progress that has been made towards realizing them. The design of the optical system is presented along with measurements of the laser beam propagation for the beam density distribution experiment. Investigations of the influence of laser beam misalignment along with measurements of the positioning accuracy of movable stages that will be used are given in light of the total expected errors.

TUPC064	Design and Commissioning of a Quadrant BPM for the LNLS Beamlines	shielding, photon, synchrotron, instrumentation	1200
	S. R. Marques, F. H. Cardoso, C. Grizolli, L. Sanfelici, M. M. Xavier LNLS, Campinas
	We have recently designed and installed the first quadrant beam position monitor in the MX2 beamline. The whole monitor, including its electronics, was installed in vacuum to reduce errors from current leakage and noise coupled outside the vacuum chamber. Aspects of the mechanical and electronic design of this fluorescence-based beam position monitor, as well as the commissioning results are presented.

TUPC082	Research and Development Program on Beam Position Monitors for NSLS-II Project	emittance, storage-ring, synchrotron, diagnostics	1245
	I. Pinayev, R. Alforque, A. Blednykh, P. Cameron, V. Ravindranath, S. Sharma, O. Singh BNL, Upton, New York
	The NSLS-II Light Source which is planned to be built at Brookhaven National Laboratory is designed for horizontal emittances below 1 nm and will provide users with ultra-bright synchrotron radiation sources. In order to utilize fully the very small emittances and electron beam sizes, submicron stability of the electron orbit in the storage ring needs to be provided. This can only be achieved with high stability beam position monitors. The research program presently carried is aimed for characterization of commercially available RF BPM receivers and on the development of high stability mechanical supports for BPM modules. The details of the program and preliminary results are presented.

TUPC097	Beam Diagnostics for the Prototype of the Cryogenic Storage Ring CSR	ion, pick-up, diagnostics, electron	1287
	T. Sieber, K. Blaum, M. Grieser, M. Lange, F. Laux, T. M. Sorg, A. Wolf, R. von Hahn MPI-K, Heidelberg
	The Cryogenic Storage Ring CSR at the MPI-K Heidelberg will be a 35m circumference, electrostatic ring, which is mainly dedicated to Molecular- and Atomic Physics experiments. To reach the low pressures (10^-15 mbar), which are necessary to achieve the required long liftetimes of the stored ions, the complete ring has to be operated at a temperature below 4K (2K in sections), which means, that it will be installed inside a large cryostat. To prove the novel cryogenics and vacuum concept of the CSR, we have built up a prototype, which is basically a segment of the CSR, housing an electrostatic ion trap. The ion trap is in the first instance used for vacuum measurements and equipment tests in the XHV range, in a later stage, it shall be an experimental facility of its own. Test operation of the Prototype is currently starting. Since the boundary conditions in the CSR are highly demanding for the beam diagnostics system, we have to perform some tests of the CSR diagnostics devices in our Prototype setup. The Poster will describe these devices and present first experimental results.

TUPC099	Wire Scanner for Transverse Beam Parameter Measurements in BEPCII	linac, electron, radiation, 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	radiation, plasma, diagnostics	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).

TUPC125	Status of the Spallation Neutron Source Superconducting RF Facility	controls, cryogenics, radiation, 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.

TUPC148	Digital LLRF for ALBA Storage Ring	controls, resonance, diagnostics, storage-ring	1419
	A. Salom, F. Pérez ALBA, Bellaterra
	ALBA is a 3 GeV, 400 mA, 3rd generation Synchrotron Light Source that is in the construction phase in Cerdanyola, Spain. The RF System will have to provide 3.6 MV of accelerating voltage and restore up to 540 kW of power to the electron beam. A Digital LLRF prototype has been developed for the Storage Ring RF Cavity. The prototype is based on the IQ modulation/demodulation technique and it has been implemented using a commercial FPGA cPCI board. The prototype has been installed in the high power RF lab of CELLS and tested to control up to 80 kW on the real Storage Ring Cavity. The test results of the control loops (amplitude, phase and tuning) will be presented, as well as the hardware structure (digital boards, analogue front ends, timing, etc.) and the system interface.

TUPD014	Detailed Design, Manufacturing and Testing of a Strip-line Extraction Kicker for CTF3 Combiner Ring	kicker, simulation, impedance, extraction	1458
	I. Rodriguez, L. García-Tabarés, E. Rodríguez García, F. Toral CIEMAT, Madrid D. Alesini, A. Ghigo, F. Marcellini, M. Zobov INFN/LNF, Frascati (Roma) T. Fowler, I. Syratchev CERN, Geneva
	The first calculations to design the CTF3 Combiner Ring extraction kicker are reported elsewhere. The last computing step before fabrication is the wakefield analysis, to determine if the bunch disturbance is acceptable. Two different codes have been used for cross-checking: CST Particle Studio and GDFidl. The computation is challenging because of the long structure (2.4 m) with a short bunch (3 mm). Besides, both transitions are not equal, because of different straight sections of the input and output beam pipe, and then the solution method is more complex. On the other hand, the main challenges for manufacturing are the long electrodes support via ceramic stand-offs and the flexible electrical connections to allow for electrodes thermal differential displacement. Special tooling has also been developed for assembly within the required tolerances. The device has been successfully leak tested. High frequency transmission coefficients and high voltage dielectric strength were also measured.

TUPD021	Sliding Force Measurements on the LHC RF Contact Plug in Modules at 15 K and in UHV	impedance, cryogenics	1473
	K. Artoos, M. Guinchard, T. Renaglia CERN, Geneva
	Some sliding RF contacts mounted in the Plug In Modules in the LHC interconnects failed during a thermal cycle between 4.2 K and room temperature. Gold-coated copper-beryllium RF fingers buckled during the warm up of the machine, indicating that one or more parameters during operation (e.g., the friction coefficient under vacuum) might be different from what was used in the calculations. This report describes the measurement of the longitudinal forces acting on the sliding RF fingers at operating vacuum and temperatures.

TUPD024	Results of ELBE Window and Coupler Tests with a Resonant Ring	klystron, controls, resonance, coupling	1479
	A. Buechner, H. Buettig, R. Schurig, G. Staats, A. Winter FZD, Dresden
	A new test bench based on a resonant ring has been built at ELBE to run window as well as coupler tests. The resonant ring is driven by a 10 kW klystron and allows tests with RF power up to 100 kW in CW mode and about 200 kW in pulsed mode. Coupler tests are done with liquid Nitrogen cooling under almost real conditions. The results of warm window and coupler tests in pulsed and CW mode are presented. Also details about the ring and a special designed coupler tip to rectangular waveguide transition are given.

TUPD032	RFQ Vacuum Brazing at CERN	rfq, alignment, linac, radio-frequency	1494
	S. J. Mathot CERN, Geneva
	The aim of this paper is to describe the vacuum brazing procedure used at CERN for the brazing of Radio Frequency Quadrupole (RFQ). The RFQ is made of high precision machined OFE copper pieces assembled together. Vacuum brazing is one of the most promising techniques used to join the individual components leading to vacuum tightness and high precision alignment. The RFQ's brazed at CERN are made of four 100 or 120 cm long vanes (two majors and two minor vanes). Our brazing procedure consists of two steps. The first step involves the brazing of the four vanes in a horizontal position. The second step consists of brazing the vacuum stainless steel flanges to the copper structure in a vertical position. The paper describes the problems encountered with the alignment and the vacuum tightness. The difficulties related to the stress relaxation of the machined copper pieces during the brazing heat treatment are discussed. In addition, the solutions developed to improve the alignment of the brazed RFQ's are also presented.

TUPD034	Review of the Mechanical Engineering Challenges Associated with the SNS Power Ramp Up	injection, diagnostics, ion-source, ion	1500
	G. R. Murdoch, D. W. Crisp, M. Holding, P. Ladd, K. G. Potter, R. T. Roseberry ORNL, Oak Ridge, Tennessee
	Since commissioning of the SNS in April 2006 the beam power has been steadily increasing towards the design intensity of 1.4 MW. Several areas of the accelerator have been shown to require modifications, upgrades or new designs of mechanical equipment to support the power ramp schedule. This paper presents mechanical engineering design work implemented since initial commissioning along with a review of current projects and discussion of mechanical engineering issues being addressed that are a direct result of design decisions made early in the project.

TUPD035	Modeling of the RF-shield Sliding Contact Fingers for the LHC Cryogenic Beam Vacuum Interconnects Using Implicit and Explicit Finite Element Formulations	simulation, superconducting-magnet, alignment, shielding	1503
	D. Ramos CERN, Geneva
	The short interconnect length between the LHC superconducting magnets required the development of an optimised RF shielded bellows module, with a low impedance combined with compensation for large thermal displacements and alignment lateral offsets. Each bellows is shielded by slender copper-beryllium fingers working as pre-loaded beams in order to provide a constant force at the sliding contact. Unless the sliding friction and some geometrical parameters of the fingers are kept within a limited range, a large irreversible lateral deflection towards the vacuum chamber axis may occur and eventually block the beam aperture. The finite element analysis presented here simulates this failure mechanism providing a complete understanding of the finger behavior as well as the influence of the various design parameters. An implicit non-linear two-dimensional model integrating friction on the sliding contacts, geometrical non-linearity and plasticity was implemented in a first stage. The design was then verified through the whole working range using an explicit formulation, which overcame the instabilities resulting from the sudden release of internal energy stored in the finger.

TUPD037	Design and Development of Intercepting Devices at the Spallation Neutron Source	radiation, 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.

TUPD038	Beam Test of a Movable Collimator (Mask) with Low Beam Impedance	impedance, positron, simulation, collider	1511
	Y. Suetsugu, K. Shibata KEK, Ibaraki A. Morishige, Y. Suzuki, M. Tsuchiya Kinzoku Giken Co. Ltd., Ebina
	A movable collimator with low beam impedance for future high-intensity machines has been investigated in KEK. The metal head of the collimator is supported by a dielectric material in order to reduce the interference with beams. The first test model was installed into the KEK B-factory (KEKB) positron ring last year. The head and the support was alumina ceramic, but only the head was coated by copper to realize a conductive layer. The support, however, was finally melted during the beam operation due to the overheating by intense electromagnetic fields induced by bunches. Based on the experience, the design was revised and the second test model was manufactured, where the head and the support were made of graphite and artificial diamond, respectively. Graphite is a conductive material with high thermal strength, and diamond, on the other hand, is a dielectric material with high thermal conductivity as well as the strength. The second test model is installed in the spring of this year, and tested again with beams during the beam operation to prove the principle. The results of the beam tests will be presented here. Y. Suetsugu, K. Shibata, A. Morishige, Y. Suzuki, M. Tsuchiya, “Design Study of a Movable Mask with Low Bema Impedance”, PRST-AB, 9, 2006, 103501.

TUPP008	An Automatic Control System for Conditioning 30 GHz Accelerating Structures	controls, gun, target, feedback	1541
	A. Dubrovsky, J. A. Rodriguez CERN, Geneva
	A software application programme has been developed to allow fast, automatic, conditioning of the accelerating structures to be high-gradient tested at 30 GHz in CTF3. The specificity of the application is the ability to control a high power electron beam which produces the 30 GHz RF power used to condition the accelerating structures. It significantly increases the amount of time useable for high power conditioning. In this paper this fast control system, the machine control system, the logging system, the graphic user control interface and the logging data visualization are described. An outline of the conditioning control system itself and of the feedback controlling peak power and pulse length is given. The software allows different types of conditioning strategies to be programmed.

TUPP011	The ESRF Temperature Monitoring System from an Operational Point of View	monitoring, radiation, 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.

TUPP012	Presentation of the New ESRF Vacuum Control Applications from an Operational Point of View	survey, controls, diagnostics, ion	1550
	D. Schmied, E. Burtin, J. M. Chaize, R. Kersevan, I. Parat, P. V. Verdier ESRF, Grenoble
	The ESRF is in operation since more than ten years. Due to the aging vacuum system, we are faced to different kinds of failures such as air or water leaks, overheating of RF-liners or poor chamber alignment. In order to anticipate these failures and therefore reduce down times, we started to develop new diagnostic tools which allow us to detect much faster and with more precision any possible failures or malfunctioning of our vacuum system. Also driven by the increase of machine performances and the continuous vacuum installations, we search for new tools to safely commission such upgrades. This paper outlines our work on the development of a new vacuum user interface, which not simply reflects the actual status of our vacuum system, but which also provides us with a dynamic survey of computed vacuum signals highlighting unusual vacuum behaviours.

TUPP023	Direct Detection of the Electron Cloud at ANKA	electron, simulation, storage-ring, synchrotron	1580
	S. Casalbuoni, A. W. Grau, M. Hagelstein, A.-S. Müller FZK, Karlsruhe U. Iriso ALBA, Bellaterra E. M. Mashkina University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen R. Weigel Max-Planck Institute for Metal Research, Stuttgart
	Low energy electrons generated by the interaction of high energy particles with the beam pipe surface can be detrimental for accelerators performances increasing the vacuum pressure, the heat load and eventually producing beam instabilities. The low energy electrons accumulating in the beam pipe are often referred to as electron cloud. In this presentation we report on the direct evidence of the electron cloud in the electron storage ring of the synchrotron light source ANKA (ANgstrom source KArlsruhe).

TUPP025	Preliminary Impedance Budget for the TPS Storage Ring	impedance, storage-ring, single-bunch, coupling	1586
	A. Rusanov NSRRC, Hsinchu
	Taiwan Photon Source (TPS) is a new third generation low-emittance synchrotron storage ring which will be built at the present site of the NSRRC in Hsinchu, Taiwan. Preliminary results of the ongoing impedance studies of the TPS are presented in this paper. The overall impedance of the vacuum chamber has been evaluated with focus on the longitudinal broad-band impedance, which can lead to bunch lengthening and microwave instability. Wakepotentials and impedances produced by each component of the storage ring have been evaluated by using 3D electromagnetic code GdfidL. Then longitudinal loss factor, longitudinal broad-band impedance and transverse kick factors were computed. Results are summarized in the table. Numerically obtained data is compared to analytical results for simplified geometries of the vacuum chamber components.

TUPP026	Impedance of Ultrarelativistic Charged Distributions in Tapering Geometries	impedance, simulation	1589
	D. A. Burton, D. C. Christie, R. W. Tucker Lancaster University, Lancaster
	We develop a scheme for obtaining the impedance, at any frequency, of a gradually tapered geometry of arbitrary cross-section containing a bunch of arbitrary profile travelling at the speed of light parallel to the axis of the taper. Coordinate-free expressions for Maxwell's equations are 2+2-split in a coordinate system adapted to the particle beam and the taper and, using an asymptotic expansion for a gradual taper, a coupled hierarchy of Poisson equations are obtained. Applications of the scheme are presented.

TUPP027	Electron Energy Dependence of Scrubbing Efficiency to Mitigate E-cloud Formation in Accelerators	electron, simulation, monitoring, luminosity	1592
	R. Cimino, M. Commisso, T. Demma, A. G. Grilli, P. Liu, M. Pietropaoli, V. Sciarra INFN/LNF, Frascati (Roma) V. Baglin CERN, Geneva P. Barone, A. Bonanno INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza)
	Recently built and planned accelerators, base their ability to reach design parameters, on the capability to reduce Secondary Electron Yield (SEY) during commissioning, hence mitigating the potentially detrimental effects of e-cloud driven machine limitations. This SEY reduction (called "scrubbing"), is due to the fact that the electrons of the cloud, hit the vacuum chamber wall, modifying its surface properties and reducing its SEY. This minimise any disturbing effects of the e-cloud to the beam. "Scrubbing" has been studied only as a function of impinging electron dose. In reality SEY modifications are only studied by bombarding surfaces with 300-500 eV electrons, but no scrubbing dependence on the bombarding electron energy has ever been discussed. The actual energy of the electrons of the cloud hitting the wall in real accelerators has never been measured accurately, while simulations predict very low electron energies (<50 eV). For this reason and given the peculiar behaviour observed for low energy electrons, we decided to study this dependence accurately. Here we present some preliminary results discussing eventual implications to machine commissioning procedures. R. Cimino et al. Phys. Rev. Lett 93, 14801 (2004).

TUPP029	Beam Coupling Impedance Measurement and Mitigation for a TOTEM Roman Pot	impedance, resonance, insertion, coupling	1598
	M. Deile, F. Caspers, T. Kroyer, M. Oriunno, E. Radermacher, A. Soter CERN, Geneva F. Roncarolo UMAN, Manchester
	The longitudinal and transverse beam coupling impedance of the first final TOTEM Roman Pot unit has been measured in the laboratory with the wire method. For the evaluation of transverse impedance the wire position has been kept constant, and the insertions of the RP were moved asymmetrically. With the original configuration of the RP, resonances with fairly high Q values were observed. In order to mitigate this problem, RF-absorbing ferrite plates were mounted in appropriate locations. As a result, all resonances were sufficiently damped to meet the stringent LHC beam coupling impedance requirements.

TUPP030	A Formula for the Electron Cloud Map Coefficient in the Presence of a Magnetic Field	electron, simulation, dipole, cyclotron	1601
	T. Demma INFN/LNF, Frascati (Roma) S. Petracca U. Sannio, Benevento
	The evolution of the electron density during multibunch electron cloud formation can be reproduced using a bunch-to-bunch iterative map formalism. The reliability of this formalism has been proved for RHIC* and LHC. The coefficients that parameterize the map function are readily obtained by fitting the results of compute-intensive electron cloud simulations. An analytic expression for the linear map coefficient that describes weak cloud behaviour from first principles has been derivied for the case of staight sections of RHIC. In this paper we generalize the model presented in ** to the case of electron cloud evolution in presence of a dipolar magnetic field and compare the results with numerical simulations. U. Iriso and S. Pegg. Phys. Rev. ST Accel. Beams 9, 071002 (2006). T. Demma et al. Phys. Rev. ST Accel. Beams 10,114401 (2007). **U. Iriso and S. Pegg. Proc. of EPAC06, pp. 357-359.

TUPP031	Electron Cloud Simulations for DAΦNE	electron, wiggler, simulation, positron	1604
	T. Demma, R. Cimino, S. Guiducci, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma)
	After the first experimental observations compatible with the presence of the electron cloud effect in the DAΦNE positron ring, a systematic study has been performed regarding the electron cloud build-up. To assess the effects of the electron cloud, simulations of the cloud build up were carried out using ECLOUD. In particular, we discuss modifications to the secondary emission model, build up for various filling patterns and different wiggler magnetic field models. The obtained numerical results are compared with experimental observations.

TUPP034	Transverse Effects due to Vacuum Mirror of RF Gun	emittance, gun, simulation, laser	1613
	I. Zagorodnov, M. Dohlus, M. Krasilnikov DESY, Hamburg E. Gjonaj, S. Schnepp TEMF, Darmstadt
	The transverse kick due to the vacuum mirror in the RF gun can negatively affect the beam emittance. In this contribution we estimate numerically and analytically the transverse wake function of European XFEL RF gun and apply it in beam dynamics studies of the transverse phase space.

TUPP036	"Scrubbing" Process of Cu Surfaces Induced by Electron Bombardment	electron, background, simulation, target	1619
	D. R. Grosso, P. Barone, A. Bonanno, M. Camarca, M. Commisso, A. Oliva, F. Xu INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza) R. Cimino INFN/LNF, Frascati (Roma)
	Energy distribution curves of electrons emitted from accelerator used metal surfaces have been measured for electron irradiation with a primary energy from 20 to 400 eV. We separated the contributions of reflected, rediffused and true-secondary electrons out from the spectra and observed significant differences in their incidence angle dependence. These results provide crucial information on the electron cloud formation in particle accelerators and may shed light on the involved physical mechanisms

TUPP037	Impedance and Instabilities for the ALBA Storage Ring	impedance, damping, synchrotron, storage-ring	1622
	T. F. Günzel, F. Pérez ALBA, Bellaterra
	The geometrical impedance in all 3 planes for most of the vacuum chamber elements of the ALBA storage ring was computed with the 3D-solver GdfidL. Optimisation of some element geometries was carried out in order to reduce dissipative losses and in general the impedance. Resistive wall impedance was calculated analytically. The thresholds of various instabilities were determined on the basis of analytically formulated threshold criteria. The most important are a HOM-driven longitudinal multibunch instability and the transverse resistive wall instability. It is proposed to combat the first one by Landau damping using partial filling and the second one by a transverse feedback system.

TUPP046	Tunable Ferroelectric Based Technologies for Accelerator Components	controls, linac, insertion, luminosity	1646
	A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio S. Kazakov KEK, Ibaraki E. Nenasheva Ceramics Ltd., St. Petersburg A. Tagantsev EPFL, Lausanne V. P. Yakovlev Fermilab, Batavia, Illinois
	Low loss ferroelectric materials can be used as key elements in RF tuning and phase shifting components to provide fast, electronic control. These devices are under development for different accelerator applications in X, Ka and L - frequency bands. The exact design of these devices depends on the electrical parameters of the particular ferroelectric material to be used- its dielectric constant, loss tangent and tunability. BST based ferroelectric-oxide compounds have been found to be suitable materials for a fast electrically-controlled tuner for BNL and for high-power fast RF phase shifters to be used for SNS vector modulation applications. We present recent results on the development of BST based ferroelectric compositions synthesized for use in high power technology components. The BST(M) ferroelectrics have been tested using a transverse dc bias field. The tunability factor vs. dc field magnitude has been evaluated and the feasibility of transverse bias tuning for ferroelectric based accelerator components has been demonstrated.

TUPP049	Experimental Electron Cloud Studies in the CERN Proton Synchrotron	electron, pick-up, extraction, proton	1655
	E. Mahner, F. Caspers, T. Kroyer CERN, Geneva
	Indications for a beam-induced electron cloud build-up are observed since 2000 for the nominal LHC beam in the PS to SPS transfer line and during the last turns before ejection from the PS. A new electron cloud setup was designed, built, and installed in the PS. It contains shielded button-type pickups, a dipole magnet, a vacuum gauge, and a dedicated stripline electrode to experimentally verify the beneficial effect of electron cloud clearing electrodes. During the 2007 run, the electron cloud effect was also clearly observed in the PS and efficient electron cloud suppression has been obtained for negative and positive bias voltages on the clearing electrode. Here, we present electron cloud measurements with different filling patterns and bunch spacings in the PS.

TUPP051	Coupling Impedance of DAΦNE Upgraded Vacuum Chamber	impedance, coupling, electron, simulation	1661
	F. Marcellini, D. Alesini, P. Raimondi, G. Sensolini, B. Spataro, A. Stella, S. Tomassini, M. Zobov INFN/LNF, Frascati (Roma)
	The DAΦNE Phi-factory at INFN LNF has been ugraded in the second half of 2007 with a scope to test a recently proposed scheme of crab waist collisions. The vacuum chamber of the collider has been substantially modified: two new low impedance interaction regions have been designed and installed, the new stripline injection kickers have been implemented, the old bellows have been substituted by the new ones and all ion clearing electrodes have been removed. In the paper we present the machine impedance study of these new vacuum chamber components and compare bunch lengthening measurements in the modified DAΦNE with simulation results.

TUPP053	Radiolocation of a HOM Source in the PEP-II Rings	single-bunch, coupling, impedance, luminosity	1664
	A. Novokhatski, J. Seeman, M. K. Sullivan SLAC, Menlo Park, California
	A signal from the antenna situated in the LER (Low Energy Ring) helped to find a broken shielded bellows in the HER (High Energy Ring) during a single HER bunch operation.

TUPP054	A Model of an Electrical Discharge in the Flange Contacts with Omega Seals at High Currents in PEP-II	radiation, 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.

TUPP058	Impedance Estimation of Diamond Cavities	impedance, simulation, storage-ring, resonance	1673
	S. A. Pande, R. T. Fielder, M. Jensen Diamond, Oxfordshire R. Bartolini JAI, Oxford
	The RF straight section of the Diamond storage ring presently consist of two CESR type SCRF cavities with a provision to install a third cavity in the future. The cavities are equipped with HOM loads and are joined to the adjacent storage ring beam pipe using tapered transitions. The RF cavities are simulated with MAFIA, CST Studio and ABCI to estimate their contribution to the total ring impedance. We also measured the resonant frequencies and Q factors of residual HOMs in these cavities. In this paper, we present the results of our measurements and simulations which lead us to an estimation of the impedance of the RF straight.

TUPP063	Characterization of the ATLAS Roman Pots Beam Coupling Impedance and Mechanics	impedance, coupling, simulation, resonance	1685
	F. Roncarolo, R. M. Jones UMAN, Manchester F. Caspers, B. Di Girolamo, T. Kroyer CERN, Geneva
	At the LHC, four Roman Pot (RP) type detectors will be installed on both sides of the ATLAS experiment with the aim of measuring elastic scattering at very small angles and determining the absolute luminosity at the interaction point. During dedicated LHC runs, the detectors will be positioned at about 1 mm from the nominal beam orbit. Numerical simulations and laboratory measurements were carried out to characterize the RP impact on the total LHC beam coupling impedance. The measurement results assess the effectiveness of RF-absorbing ferrite plates that have been mounted in convenient locations in order to damp high Q resonances of the RP structure. In addition, we review the RP mechanics emphasizing the accuracy and reproducibility of the positioning system.

TUPP068	Bench Measurements of the Low Frequency Transverse Impedance of the CERN LHC Beam Vacuum Interconnects with RF Contacts	impedance, cryogenics, coupling, betatron	1697
	B. Salvant EPFL, Lausanne F. Caspers, E. Métral CERN, Geneva F. Roncarolo UMAN, Manchester
	The low frequency longitudinal and transverse impedances of the CERN Large Hadron Collider (LHC) have to be specifically minimized to prevent the onset of coherent instabilities. The LHC beam vacuum interconnects were designed as Plug In Modules (PIMs) with RF contacts to reduce their coupling impedances, but the resulting contact resistance is a concern, as this effect is difficult to estimate. High sensitivity measurements of the transverse impedance of a PIM at low frequency using a coil probe are presented. In particular, the increase of the transverse impedance of the PIM when it is elongated to its operating position is discussed in detail. Finally, the issue of non-conforming contact resistance is also addressed.

TUPP073	Bench-top Impedance Measurements for a Rotatable Copper Collimator for the LHC Phase II Collimation Upgrade	impedance, collimation, simulation, target	1703
	J. C. Smith, K. L.F. Bane, J. E. Doyle, L. Keller, S. A. Lundgren, T. W. Markiewicz, C.-K. Ng, L. Xiao SLAC, Menlo Park, California
	The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite collimators with 30 high Z, low impedance Phase II collimators. The design for the collimation upgrade has not been finalized. One option is to use metallic rotatable collimators and this design will be discussed here. Simulations have been performed in MAFIA to study both the resistive wall and geometric impedance contributions of our rotatable collimator design. Benchtop stretched coil probe impedance measurements have also been performed on prototype components to directly measure the low frequency impedance contributions. The design also calls for an RF contact interface at the jaw end. This contact resistance must be a small fraction of a milliohm in order to limit transverse impedance. DC resistance measurements in a custom built test chamber have been performed to test the performance of various metal pairs and surface coatings.

TUPP075	Numerical Studies of Resistive Wall Effects	electromagnetic-fields, emittance, impedance, electron	1709
	A. V. Tsakanian Uni HH, Hamburg M. Dohlus, I. Zagorodnov DESY, Hamburg
	In this paper we describe a new numerical code to calculate wakefields of resistive wall geometries. Our code is based on conformal implicit scheme. It allows to estimate wakefields of very short bunches taking into account transitive effects neglected in the European XFEL impedance budget so far.

TUPP076	Longitudinal and Transverse Impedances of XFEL Kicker Vacuum Chamber	impedance, kicker, dipole, resonance	1712
	A. V. Tsakanian, J. Rossbach Uni HH, Hamburg M. Ivanyan CANDLE, Yerevan
	In European XFEL project beam delivery system the kicker magnet vacuum chamber design is composed of the ceramic pipe coated with Titanium Stabilized High Gradient Steel. In this paper the results of the study for the longitudinal and transverse impedances for such a laminated vacuum chamber are presented. The field matching technique is used to calculate the vacuum chamber impedances. The loss and kick factors are given.

TUPP081	Longitudinal Wakefields and Impedance in the CSNS/RCS	impedance, extraction, injection, kicker	1718
	N. Wang, Q. Qin IHEP Beijing, Beijing
	With the more general expressions developed for the wakefield generated by nonrelativistic beam, the impedances of some main vacuum parts of the Rapid Cycling Synchrotron (RCS) of the China Spallation Neutron Source (CSNS) are calculated and compared with the relativistic case. An impedance model is then proposed for the ring. With this impedance model, beam instabilities in the CSNS/RCS are investigated. N. Wang and Q. Qin, Phys. Rev. ST Accel. Beams 10, 111003 (2007)

TUPP084	Parallel Computation of Integrated Electromagnetic, Thermal and Structural Effects for Accelerator Cavities	simulation, gun, emittance, space-charge	1724
	V. Akcelik, A. E. Candel, A. C. Kabel, K. Ko, L. Lee, Z. Li, C.-K. Ng, L. Xiao SLAC, Menlo Park, California
	The successful operation of accelerator cavities has to satisfy both rf and mechanical requirements. It is highly desirable that electromagnetic, thermal and structural effects such as cavity wall heating and Lorentz force detuning in superconducting rf cavities can be addressed in an integrated analysis. Based on the SLAC parallel finite-element code infrastructure for electromagnetic modeling, a novel multi-physics analysis tool has been developed to include additional thermal and mechanical effects. The speedup from parallel computation enables virtual prototyping of accelerator cavities on computers, which would substantially reduce the cost and time of a design cycle. The multi-physics tool will be applied to the LCLS rf gun and a superconducting rf gun cavity.

TUPP086	Efficient 3D Space Charge Calculations by Self-adaptive Multigrid Methods Using the Chombo Framework	space-charge, brightness, electron, simulation	1730
	C. R. Bahls, G. Pöplau, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock
	Current and future accelerator design requires efficient 3D space charge computations for high brightness bunches which should be as precise and fast as possible. One possible approach for space charge calculations is the particle-mesh-method, where the potential is calculated in the rest frame of the bunch by means of Poisson's equation. For an efficient solution of this elliptic PDE an appropriate adaptive discretization of the domain is required. Especially it has to take into account discontinuities in the distribution of the particles. The solution method we investigate in this paper is a self-adaptive multigrid method applying composite grids. To accomplish this, we use the library Chombo* which is being developed as a framework for adaptive multiresolution solvers for elliptic and hyperbolic partial differential equations. *Developed and distributed by the Applied Numerical Algorithms Group of Lawrence Berkeley National Lab., http://seesar.lbl.gov/ANAG/chombo/

TUPP089	Implementation of Fringe Field Dipole Magnets into the V-Code Beam Dynamics Simulation Tool	simulation, dipole, focusing, multipole	1738
	S. S. Franke, W. Ackermann, B. Steiner, T. Weiland TEMF, Darmstadt J. Enders, C. Hessler, Y. Poltoratska TU Darmstadt, Darmstadt
	Fast online beam dynamics simulations can advantageously assist the machine operators at various particle accelerator machines because they provide a more detailed insight into the actual machine status. Based on the moment approach a fast tracking code named V-Code has been implemented at TEMF. Within the SFB 634 project the V-Code beam dynamics simulation tool is supposed to be installed at the Superconducting Darmstadt LINear ACcelerator S-DALINAC which is designed as a re-circulating linear accelerator. In order to be able to simulate the entire beam line, an implementation of fringe field dipole magnets is mandatory. Unlike a hard edged field approach the fringe fields influence the beam focusing and its inhomogeneity results in a non-circular bunch motion. For an accurate reproduction of the transverse motion specialized techniques to obtain and to handle the reference path in V-Code together with the 3D-field data along the curved trajectory had to be developed. In the paper a summary of implementation details together with simulation results will be provided.

TUPP124	Status of the Particle Therapy Accelerator System Built by DANFYSIK A/S	synchrotron, dipole, ion, quadrupole	1815
	S. P. Møller, T. Andersen, F. Bødker, A. Baurichter, M. Budde, P. A. Elkiaer, C. E. Hansen, N. Hauge, T. Holst, I. Jensen, L. K. Kruse, S. M. Madsen, M. Schmidt Danfysik A/S, Jyllinge K. Blasche BTE Heidelberg, Ingeniurbüro, Schriesheim B. J. Franczak GSI, Darmstadt
	Danfysik and Siemens have entered a cooperation to market and build Particle Therapy* systems for cancer therapy. The accelerators will consist of an injector (7 MeV/u proton and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u in less than 1s. These beams can be slowly extracted over a period of up to 10s and delivered to treatment rooms through a choice of fixed-angle horizontal and semi-vertical beamlines and Gantry Systems. The intensity for protons and carbon ions will be sufficient for the needs of scanning beam applications. The design of a particular system, with three horizontal beamlines and one semi-vertical (45°) beamline, will be described. At the time of EPAC08, most components have been manufactured and hardware tested. The detailed layout of the facility will be presented, together with some of the components and their performance. *Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.

TUPP131	Status of the Linac Components for the Italian Hadrontherapy Centre CNAO	linac, rfq, ion, controls	1833
	H. Vormann, C. M. Kleffner, A. Reiter, B. Schlitt GSI, Darmstadt G. Clemente, U. Ratzinger IAP, Frankfurt am Main
	The IH-DTL for the Linac in the Italian National Center for Hadron Therapy in Oncology CNAO will accelerate different ion species (C⁴⁺, O⁶⁺,3He⁺, H²⁺) to an energy of 7 MeV/u. The combined rebunching and accelerating beam dynamic concept ("KONUS", "Kombinierte Null Grad Struktur", combined zero degree structure) requires a real voltage distribution in all 56 accelerator gaps (distributed in 4 sections) matching very close to the design voltage distribution. The tuning of the mechanically finished and copper plated cavity started in January 2007, based on the experience from the similar IH-DTL for the HIT linac ("Heidelberger Ionenstrahl-Therapiezentrum", the Heidelberg ion beam therapy center). Very small differences in mechanical measures caused modified starting conditions, resulting in varying number and shape of fixed tuners, but nevertheless accurate field distribution. The CNAO Linac is at presently under commissioning, all linac components except the IH-DTL have been delivered to the center in November 2007.

TUPP141	Electron Accelerators for Cleaning Flue Gases and for Oil Liquefaction	electron, radiation, cathode, 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, radiation, 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.

WEOBM04	LHC: The World's Largest Vacuum Systems being Commissioned at CERN	ion, cryogenics, injection, cathode	1959
	J. M. Jimenez CERN, Geneva
	When it switches on in the spring of 2008, the 26.7 km Large Hadron Collider (LHC) at CERN, will have the world's largest vacuum system operating over a wide range of pressures and employing an impressive array of vacuum technologies. This system is composed by 54 km of UHV vacuum for the circulating beams and 24 km of insulation vacuum around the cryogenic magnets operated mainly at 1.9 K. Over the 54 km of UHV beam vacuum, 48 km of this must be at cryogenic temperature (1.9 K). The remaining 6 km of beam vacuum containing the insertions is at ambient temperature and uses non-evaporable getter (NEG) coatings – a vacuum technology that was born and industrialized at CERN. The pumping is completed using 600 ion pumps to remove noble gases and 1000 gauges are used to monitor the pressures. The cryogenic insulation vacuum, while technically less demanding, is impressive by its size - 24 km in length, 900 mm in diameter for a total volume of 640 m³. Once cooled at 1.9 K, the cryogenic pumping allows reaching pressure in the 10^-6 mbar range. This paper described the entire vacuum system and the challenges of the design, manufacturing, installation and commissioning phases.
	Slides

WEIM03	Industrialization of Superconducting Accelerator Module Production	linac, alignment, collider, free-electron-laser	1964
	B. Petersen DESY, Hamburg
	As part of the EUROFEL Design Study, two industrial partners recently took part in the assembly of superconducting TESLA modules for FLASH. The aim was to transfer the module assembly knowledge to industry and to analyse the assembly sequence to perpare for industrial production for future projects such as the XFEL. This talk should discuss the conclusions of this study and identify issues that must be considered when transferring SRF technology to industry.
	Slides

WEIM04	Highly Customized Industrialized Linacs for Applications in Scientific Research	linac, electron, proton, RF-structure	1967
	C. Piel ACCEL, Bergisch Gladbach
	Industrial capabilities and experience in linac design and manufacturing shall be given for the various types of scientific applications. Furthermore the process from linac contracting through establishing a project team and adequate human and machine ressources for fulfilling the technical, schedule and pricing requirements shall be described.
	Slides

WEPC001	Status of PETRA III	wiggler, damping, alignment, quadrupole	1977
	K. Balewski DESY, Hamburg
	PETRA III is a new hard x-ray synchrotron radiation source which will be operated at 6 GeV with a extremely low horizontal emittance of 1nmrad. This new light source will be the result of a conversion of the existing accelerator PETRA II into a light source. The conversion comprises the complete rebuilding of one eighth of the 2304 m long storage ring, which will then house 14 undulator beam lines and the modernisation and refurbishment of the remaining seven eighths. In addition two 100m long damping wiggler section will be installed which are required to achieve the small design emittance. During the last four years extensive design work, construction and production of components have been carried out to prepare for the conversion. Since the 2nd of July the construction activities have started when PETRA II was no longer needed as a pre-accelerator for HERA. At present the project is still on track so that operation with beam is foreseen for January 2009 and first user experiments in the second half of 2009. In this report a brief overview of the project and the status of the constructional work, the different components and the installation in the tunnel will be given.

WEPC006	Beam Lifetime and Collective Effects in Taiwan Photon Source	impedance, ion, insertion, insertion-device	1992
	P. J. Chou, H.-P. Chang, C.-C. Kuo, W. T. Liu, H.-J. Tsai NSRRC, Hsinchu
	The design of Taiwan Photon Source (TPS) has a natural emittance less than 2 nm-rad and low emittance coupling. The nominal rms bunch length is less than 3 mm. Several small-gap undulators are planned to provide x-ray photon beam with extremely high brightness. The vertical gap of these undulators are in the range of 5-7 mm. The TPS ring will be operated at top-up mode with high beam current. Various collective effects due to high beam current are investigated. Impacts of small-gap undulators to the beam lifetime are carefully studied. The results of theoretical analysis are presented. Proposals to overcome deleterious effects due to high beam current and small-gap undulators are also discussed.

WEPC007	Vacuum Performance of the Diamond Light Source In-vacuum Insertion Devices	storage-ring, target, ion, insertion	1995
	M. P. Cox, S. Bryan, B. F. Macdonald, H. S. Shiers Diamond, Oxfordshire
	Diamond Light Source is the UK's new 3 GeV 3rd generation synchrotron light source with a 562 m circumference electron storage ring. At the start of user operations in January 2007, 5 in-vacuum undulators were in operation and a further 3 units have been installed subsequently. This paper describes the vacuum performance of these devices. 3 different mechanical configurations with different undulator canting angle and different pumping arrangements of the interconnecting vessels are installed. One configuration has non-evaporable getter (NEG) coated interconnecting vessels. Vacuum simulations were carried out on these configurations as part of the vacuum design process to predict their performance. Following final magnetic characterization, each of the devices was vacuum assembled and baked ex-situ for an extended period and then installed under dry nitrogen purge conditions, eliminating the need for a time-consuming in-situ bakeout in most cases. After a period of pump down and beam conditioning, the operating pressures in all the in-vacuum undulators were below the target specification and produced acceptably low Gas Bremsstrahlung radiation levels in the beamlines.

WEPC008	Status of the SSRF Storage Ring	storage-ring, feedback, site, superconducting-RF	1998
	Z. M. Dai, D. K. Liu, L. G. Liu, L. Yin, Z. T. Zhao SINAP, Shanghai
	The SSRF storage ring is composed of 20 DBA cells with energy of 3.5GeV and circumference of 432m. The installation of the SSRF storage ring was started on June 11, 2007, and finished in the beginning of Dec. 2007. The system tests of hardware and software for storage ring were completed in the middle of Dec. 2007. The commissioning of the storage ring started on Dec. 21, 2007, and the 100mA stored beam was achieved for the first time on Jan. 3, 2008. The design, installation and commissioning of the SSRF storage ring are described in this paper

WEPC009	Progress of ALBA	storage-ring, linac, booster, quadrupole	2001
	D. Einfeld ALBA, Bellaterra
	The construction of the ALBA Synchrotron Light Source in Barcelona (Spain) is well advanced. In spring of this year the 100 MeV Linac will be installed and results from the commissioning will be reported on this conference. The different components for the accelerators have successfully completed the prototyping phase and the different series are now under production. Installation of Booster and Storage Ring should start in summer of this year and commissioning is planned for spring 2009. The construction status will be presented.

WEPC011	Using Multi-bend Achromats in Synchrotron Radiation Sources	lattice, dipole, emittance, sextupole	2007
	M. Eriksson, A. Hansson, S. C. Leemann, L.-J. Lindgren, M. Sjöström, E. J. Wallén MAX-lab, Lund L. Rivkin, A. Streun PSI, Villigen
	Multi-bend achromats offer small electron beam emittance, large energy acceptance and a good dynamic aperture. Two examples are discussed in the article, each using 7-bend achromats; a 12 achromat lattice and a 20 achromat one. Some possible technical solutions associated with the dense lattices are discussed: magnet technology, vacuum system and RF system. Some characteristics of the two rings are also presented; effects of Intra Beam Scattering, Touschek life-time and the electron beam parameter values.

WEPC016	Operation Status and Performances Upgrade on SOLEIL Storage Ring	undulator, feedback, photon, insertion	2022
	J.-M. Filhol, J. C. Besson, F. Bouvet, P. Brunelle, L. Cassinari, M.-E. Couprie, J.-C. Denard, C. Herbeaux, J.-F. Lamarre, J.-P. Lavieville, P. Lebasque, M.-P. Level, A. Loulergue, P. Marchand, A. Nadji, L. S. Nadolski, R. Nagaoka, M.-A. Tordeux SOLEIL, Gif-sur-Yvette
	SOLEIL is the French 2.75 GeV third generation synchrotron light source delivering beam to users since January 2007. Beginning of 2008 up to 13 beam-lines are taking beam, 7 from insertion devices (IDs), 2 from IR ports, and 4 from dipole ports, and 6 of them are open to external Users. Users have a full control of their IDs. With a 300 mA stored beam current in multi-bunch filling pattern, and position stability in the few micron range, the main target performances have been reached. A beam of 50 mA in 8 bunches was delivered to users for the first time in December 2007 for time structure experiments. Operation and performance status will first be given, namely subsystem behaviour (RF, vacuum, �), beam optics, orbit stability, beam lifetime, and operation statistics. Then the main objectives for 2008 will be reviewed: delivery of 4000 hours of user beam time, installation and commissioning of a second cryomodule for reaching the 500 mA current target, construction and installation of 6 new IDs leading to a total number of 17, improvement of the orbit stability with a fast orbit feedback complementary to the slow orbit one, and preparation for top-up operation.

WEPC024	Low Beta Structure for the ANKA Storage Ring	optics, dynamic-aperture, emittance, injection	2034
	E. Huttel, I. Birkel, A.-S. Müller, P. Wesolowski FZK, Karlsruhe
	The ANKA storage ring has a fourfold symmetry with a double DBA structure. Four (~1.7 m) straight sections are used for the RF and the injection. Four sections (~ 4.5 m) are used for insertion devices (three installed). The beta functions in these sections are 14, respectively 7 m (horizontal/vertical). This is not ideal for small gap (7 mm) insertion devices. Reducing the vertical beta function to 2 m is possible with the present magnet configuration and is done for special user operation. Reducing both the horizontal and vertical beta function is favoured for one future beam line. This will afford a change of the present magnet configuration. Different options have been calculated and will be discussed.

WEPC025	First 18 Months Operation of the Diamond Storage Ring RF System	storage-ring, controls, resonance, synchrotron	2037
	M. Jensen, M. Maddock, P. J. Marten, S. A. Pande, S. Rains, A. F. Rankin, D. Spink, A. V. Watkins Diamond, Oxfordshire
	Since the Diamond Light Source became operational in January 2007, the storage ring RF system has operated for 5000 hours in 2007 and is scheduled to operate for 5350 hrs in 2008. This paper presents some of the key challenges of the storage ring RF system including reliability, performance observations and future improvements.

WEPC060	Studies on the Beam Current Dependent Phenomena in the BEPC-II Storage Rings	single-bunch, electron, luminosity, synchrotron	2130
	Q. Qin, N. Huang, W. B. Liu, Y. D. Liu, Y. M. Peng, J. Qiu, D. Wang, J. Q. Wang, N. Wang, X. H. Wang, Y. Wei, X. M. Wen, J. Xing, G. Xu, C. H. Yu, C. Zhang, Y. Zhang, Z. Zhao, D. M. Zhou IHEP Beijing, Beijing
	The upgrade project of the Beijing Electron Positron Collider (BEPC-II) has been being commissioned since Nov. 2006. Besides the commissioning of the luminosity, which is expected to be 100 times higher than the BEPC, the BEPC-II also provided beam to the synchrotron radiation users as a light source during these two years. Some beam current dependent phenomena, such as bunch lengthening, single beam instabilities, blow-up in collision, etc., in both collision and synchrotron radiation modes are observed in the machine performance. In this paper, some observations and analyses on these phenomena are given.

WEPC074	The Injection and Extraction Kicker Magnets of the Elettra Booster	extraction, kicker, injection, booster	2166
	R. Fabris, G. Pangon ELETTRA, Basovizza, Trieste
	The design, realization and performance of the injection and extraction Kicker magnets of the Booster of Elettra are presented. A window-frame geometry has been chosen due to its transverse symmetry in order to obtain a good field symmetry. A suitable layout for in vacuum operation has been developed. The magnetic core is made by CMD 5005 ferrite blocks, assembled in a stainless steel case, obtaining a single module; one module has been used for the injection Kicker and two such modules, connected in parallel, have been used for the extraction Kicker. In both cases the magnet modules have been installed in stainless steel vacuum chambers. The design of the magnetic core has been checked using the well known 2D POISSON code, thanks to the fact that the magnet’s gap is narrow compared to its length.

WEPC078	Eddy Current Septum Magnets for Booster Injection and Extraction and Storage Ring Injection at SSRF	septum, injection, storage-ring, booster	2177
	M. G. Gu, R. Chen, Z. H. Chen, B. Liu, L. Ouyang SINAP, Shanghai
	There are 6 in-vacuum eddy current septum magnets used for injection and extraction in the SSRF booster and storage ring. The booster extraction thick septum magnets generate magnetic field over 1 Tesla, special attentions were paid to coils and their support design because of the shock force and the high heat which is hard to be dissipated in vacuum environment. The good transverse homogeneity in the gap has been achieved by careful design, precise machining and accurate assembly. An extremely low leakage field on the stored beam is another key feature of these magnets thanks to the high permeability Mu metal. Magnetic field measurement was conducted with both point coil and long integral coil, and the results agreed well with the OPERA-2d/3d simulations. An inner tube with RF finger flanges at each end is added to keep the continuity of impedance for the circulating beam. There is no vacuum separation between the inner tube and magnet chamber.

WEPC081	Improvement on Pulsed Magnetic Systems at SOLEIL	kicker, injection, storage-ring, pulsed-power	2183
	P. Lebasque, R. Ben El Fekih, M. Bol, J.-P. Lavieville, A. Loulergue, D. Muller SOLEIL, Gif-sur-Yvette
	Two "machine study" kicker systems have been designed, built and installed on the storage ring of SOLEIL to kick the stored beam in the horizontal and the vertical planes, in order to investigate the non-linear dynamic of the ring with different insertion devices configurations. This article will describe the different aspects of the design of the two magnets and vacuum chambers, and of their fast high current pulsed power supplies, working with high voltage switches based on MOS transistors. The electrical and magnetic measurements will be presented. The second part of the paper will describe the modifications brought to the thick septum magnet system of the ring injection, in view to reduce the stray field seen by the stored beam. It also presents the different tunings performed on the four injection kickers, in order to reduce the amplitude of the residual bump along the ring down to a very low level. Theses adjustements are aimed to minimize the disturbances on the stored beam when operating the Synchrotron in "Top Up" injection mode.

WEPC093	Finalized Design of the Pulsed Magnets and their PS for SESAME Ring Injection	kicker, septum, injection, power-supply	2210
	S. Varnasseri, A. Nadji SESAME, Amman J.-P. Lavieville, P. Lebasque SOLEIL, Gif-sur-Yvette
	The design of the SESAME storage ring injection pulsed magnet systems have been improved in order to take benefit of the most recent realizations in Synchrotrons. These pulsed systems are optimised for the injection into the 2.5GeV storage ring of the 800 MeV electrons beam prepared by the Booster. The septum magnet is based on a direct driven septum technology, out of vacuum, with a thin vacuum chamber of rectangular cross section permitting to get a good field transverse homogeneity. The four kicker magnets will be of the window frame geometry, around a racetrack alumina vacuum chamber, integrating a forced air cooling in order to avoid significant thermal heating due to the stored beam. These magnets can be opened for backup and will be completely CEM shielded. Their pulsed power supplies will be built based on solid-state HV switches, even for short half-sine pulses generation.

WEPC098	Development of Cryogenic Undulator CPMU at SOLEIL	permanent-magnet, undulator, cryogenics, radiation	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.

WEPC103	Design of a Cold Vacuum Chamber for Diagnostics	electron, synchrotron, diagnostics, storage-ring	2240
	S. Casalbuoni, T. Baumbach, A. W. Grau, M. Hagelstein, R. Rossmanith FZK, Karlsruhe V. Baglin, B. Jenninger CERN, Geneva R. Cimino INFN/LNF, Frascati (Roma) M. P. Cox Diamond, Oxfordshire E. M. Mashkina University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen E. J. Wallén MAX-lab, Lund R. Weigel Max-Planck Institute for Metal Research, Stuttgart
	Preliminary studies performed with the cold bore superconducting undulator installed in the ANKA storage ring suggest that the beam heat load is mainly due to the electron wall bombardment. Low energy electrons (few eV) are accelerated by the electric field of the beam to the wall of the vacuum chamber, induce non-thermal outgassing from the cryogenic surface and heat the undulator. In this contribution we report on the design of a cold vacuum chamber for diagnostics to be installed in the ANKA (ANgstrom source KArlsruhe) storage ring and possibly in third generation light sources. The diagnostics implemented are: retarding field analyzers to measure the electron energy and flux, temperature sensors to measure the total heat load, pressure gauges, and a mass spectrometer to measure the gas content. The aim of this device is to gain a deeper understanding on the heat load mechanisms to a cold vacuum chamber in a storage ring and find effective remedies. The outcome of the study is of relevance for the design and operation of cold bore superconducting insertion devices in synchrotron light sources.

WEPC105	Construction of a Cryogenic Permanent Magnet Undulator at ESRF	undulator, cryogenics, simulation, laser	2243
	J. Chavanne, M. Hahn, R. Kersevan, C. A. Kitegi, C. Penel, F. Revol ESRF, Grenoble
	A cryogenic permanent magnet undulator (CPMU) has been constructed at ESRF. The device is a full scale in-vacuum undulator with a magnetic length of 2 metres and a period of 18 mm. This prototype is still compatible with an operation at room temperature, it has been mainly used to investigate the technological issues connected to the operation at low temperature. An important effort has been dedicated to the construction of a complete measuring bench operated in-vacuum with the undulator at cryogenic temperatures around 150 K. The bench includes a stretched wire system for field integral measurement and a local field measurement assembly suitable for the accurate characterization of the optical phase error along the undulator. The main results of the magnetic measurements will be presented , they confirm the simulations performed with RADIA using NdFeB permanent magnet material models at low temperature. The cryogenic system used to cool the undulator is based on a reliable liquid nitrogen closed loop. The heat budget of the device will be discussed. The prototype has been installed on the ESRF ring in December 2007. The first results of operation will be presented.

WEPC108	Portable Magnetic Field Measurement System	controls, laser, feedback, undulator	2252
	J. Kulesza, A. Deyhim, E. Van Every, D. J. Waterman Advanced Design Consulting, Inc, Lansing, New York K. I. Blomqvist MAX-lab, Lund
	This portable magnetic field measurement system is a very sophisticated and sensitive machine for the measurement of magnetic fields in undulators (Planer, EPU, and Apple II), wigglers, and in-vacuum ID units. The magnetic fields are measured using 3 axis hall-effect probes, mounted orthogonally to a thin wand. The wand is mounted to a carriage that rides on vacuum air bearings. The base is granite. A flip coil is provided on two vertical towers with X, Y and Theta axes. Special software is provided to assist in homing, movement, and data collection.

WEPC109	Development of an In-vacuum Undulator System for U-SAXS Beamline at PLS	undulator, controls, monitoring, ion	2255
	D. J. Waterman, A. Deyhim, J. Kulesza, E. Van Every Advanced Design Consulting, Inc, Lansing, New York K. I. Blomqvist MAX-lab, Lund
	The design of a hybrid in-vacuum undulator with 20mm period, effective peak field of 1.05 Tesla, and 1800 mm magnetic length is being presented. The design requirements and mechanical difficulties for holding, positioning, and driving the magnetic arrays are explored. The structural and finite element analysis, magnetic design, and electrical considerations that influenced the design are then analyzed. This in-vacuum undulator (IVUN) is being installed at Pohang Accelerator Laboratory (PAL) for U-SAXS (Ultra Small Angle X-ray Scattering) beamline. The IVUN will generate undulator radiation up to ~14 keV using higher harmonic (upto 9th) undulator radiation with 2.5 GeV PLS electron beam.

WEPC115	Development of IVUN at Pohang Accelerator Laboratory	undulator, radiation, 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.

WEPC120	An In Vacuum Wiggler WSV50 for Producing Hard X-rays at SOLEIL	wiggler, photon, insertion, insertion-device	2288
	O. Marcouillé, P. Brunelle, O. V. Chubar, M.-E. Couprie, J.-M. Filhol, C. Herbeaux, J. L. Marlats, A. Mary, K. Tavakoli SOLEIL, Gif-sur-Yvette
	SOLEIL is a medium energy storage ring (2.75 GeV) operating since 2006. The production of intense high energy photon beams requires insertion devices with high magnetic field and large number of periods. To cover the 20 keV-50 keV Photon Energy range, an in vacuum wiggler has been preferred to a superconducting wiggler. This choice results from a compromise between photon flux, investment and running cost. Deep studies have been performed to find the optimum magnetic field and period producing the maximum flux in the dedicated spectral range (20-50 keV). The wiggler is composed of 38 periods of 50 mm producing a 2.1 T magnetic field at a minimum gap of 5.5 mm. To minimize the high magnetic forces acting between the magnet arrays (10 tons), two compensation systems, composed of either springs or magnet blocks, have been designed. This paper presents the spectral performances of the wiggler compared with an optimized superconducting wiggler, the mechanical and magnetic design of the wiggler and the first tests of the compensation system.

WEPC121	Magnetic Measurement Device for Superconductive Undulator Mock-up Coils at ANKA	undulator, synchrotron, electron, superconductivity	2291
	E. M. Mashkina, B. K. Kostka, E. Steffens University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen T. Baumbach, A. Bernhard, D. Wollmann University of Karlsruhe, Karlsruhe S. Casalbuoni, A. W. Grau, M. Hagelstein, R. Rossmanith FZK, Karlsruhe
	A device for precise magnetic measurements of superconductive coils was designed, built and installed at the synchrotron radiation source ANKA, Forschungszentrum Karlsruhe. Accurate magnetic field measurements are a prerequisite for the characterization and optimization of insertion devices. The new device allows measuring the magnetic field magnitude of test coils with a longitudinal precision of 10 μm using a 2D Hall probe bench. The cylindrical liquid He cryostat allows mounting coils of maximum dimensions 50 cm in length and 30 cm in diameter. The set-up is computer controlled. The contribution will present the new device as well as the results obtained.

WEPC139	Recent Experience in the Fabrication and Brazing of Ceramic Beam Tubes for Kicker Magnets at FNAL	kicker, booster, controls, background	2335
	C. R. Ader, C. C. Jensen, R. E. Reilly, D. Snee, J. H. Wilson Fermilab, Batavia, Illinois
	Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil (titanium/inconel) alloy brazing material are stacked in the furnace and then brazed in the furnace at 1000°C. The ceramic specified is Alumina 99.8% Al₂O₃, a strong recrystalized high-alumina fabricated by slip casting. Recent experience at Fermilab with the fabrication and brazing of these tubes has brought to light numerous problems including tube breakage and cracking and also the difficulty of brazing the tube to produce a leak-tight joint. These problems may be due to the ceramic quality, voids in the ceramic, thinness of the wall, and micro-cracks in the ends which make it difficult to braze because it cannot fill tiny surface cracks which are caused by grain pullout during the cutting process. Solutions which are being investigated include lapping the ends of the tubes before brazing to eliminate the micro-cracks and also metallization of the tubes.

WEPC141	Septa and Distributor Developments for H^- Injection into the Booster from Linac4	linac, injection, septum, booster	2338
	J. Borburgh, B. Balhan, T. Fowler, M. Hourican, W. J.M. Weterings CERN, Geneva
	The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H^- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H^- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H^- beam, the first of the BS magnets will have to be a septum like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented.

WEPC142	Design of Pulsed Magnets for the Taiwan Photon Source	septum, kicker, storage-ring, injection	2341
	C.-H. Chang, C. K. Chan, J.-R. Chen, C.-S. Fann, M.-H. Huang, C.-S. Hwang, F.-Y. Lin, Y.-H. Liu, C.-S. Yang NSRRC, Hsinchu
	A new Taiwan Photon source requires a high stability pulsed magnets for the top-up mode injection operation. We present a preliminary design of the pulsed magnets used for injection into the 3 GeV storage ring. A 0.6 m long kicker magnet prototype is fabricated for testing the field performance. The field testing results are described in this work. The septum magnet with a 0.4 mm thickness stainless steel vacuum chamber is real tested at 3 Hz operation. The field performance, the stray fields and the eddy current effect are presented in this paper.

WEPC150	Fast Local Bump System for Helicity Switching at the Photon Factory	undulator, photon, kicker, alignment	2356
	K. Harada, Y. Kobayashi, T. Miyajima, S. Nagahashi, T. Obina KEK, Ibaraki S. Matsuba Hiroshima University, Graduate School of Science, Higashi-Hiroshima
	Two APPLE-II type variably polarizing undulators will be installed at the south straight section of the PF (Photon Factory) ring. The 10Hz fast orbit switching in these undulators will be conducted for the helicity switching. The required angular difference of the orbits in two undulators is 0.3mrad. The five identical bump magnets and AC power supplies are manufactured to make 10Hz time varying local bumps. In order to achieve the local bump and prevent the fluctuation of the beam orbit with the effects of the insertion devices and magnetic errors, the feed forward correction with the bump magnets and the feedback correction with the fast steering magnets are required. In this presentation, the measurement results of the magnetic field and the frequency response, the configuration of the control system, and the simulation results to achieve the local bumps are shown.

WEPC160	Eddy-current Effect on Field Multipoles Arising in Dipole Magnets with Elliptic and Rectangular Beam Pipe	multipole, dipole, quadrupole, coupling	2383
	E. Perevedentsev, A. L. Romanov BINP SB RAS, Novosibirsk
	We present an analytical evaluation of the field-distortion effect from eddy currents induced by variation of magnetic field of dipole magnets with elliptic or rectangular beam pipe of finite conductivity. The pipe sizes and aspect are arbitrary except that for practical reasons we assume the pipe wall thickness is small as compared to the skin depth. Handy formulas are presented for the field multipoles arising from non-round shape of the beam pipe.

WEPC163	Modification of a Spare Septum Magnet for SNS Ring Injection Dump Beam Line	septum, simulation, proton, injection	2389
	J. G. Wang ORNL, Oak Ridge, Tennessee
	The SNS ring injection dump septum magnet has been suffering the heaviest beam losses since the ring commissioning. These beam losses are caused by a number of design and operation problems such as incorrect location of one chicane dipole, incorrect chicane dipole setting, and inadequate aperture of the injection dump septum. We have modified a spare septum by increasing its vertical and horizontal aperture and by adding specially designed z-bumps for one of the waste beams. This paper reports the detailed modification results, including 3D particle trajectory calculations and experimental measurements.

WEPD001	The Quality Control of the LHC Continuous Cryostat Interconnections	controls, monitoring, induction, collider	2398
	F. F. Bertinelli, D. Bozzini, P. Cruikshank, P. Fessia, W. Maan, A. Poncet, S. Russenschuck, F. Savary, Z. Sulek, J.-P. G. Tock, D. Tommasini, L. R. Williams CERN, Geneva P. B. Borowiec, A. Kotarba, S. Olek HNINP, Kraków A. Grimaud ALL43, Saint-Genis-Pouilly L. Vaudaux IEG, St-Genis-Pouilly
	The interconnections between the Large Hadron Collider (LHC) magnets have required some 40 000 TIG welded joints and 65 000 electrical splices. At the level of single joints and splices, non-destructive techniques find limited application: quality control is based on the qualification of the process and of operators, on the recording of production parameters, and on production samples. Visual inspection and process audits were the main techniques used. At the level of an extended chain of joints and splices - from a 53.5 m half-cell to a complete 2.7 km sector - quality control is based on vacuum leak tests, electrical tests and RF microwave reflectometry that progressively validated the work performed. Subsequent sector pressure tests, cryogenic circuits flushing with high pressure helium and cool-downs revealed a few unseen or new defects. The nature of defects is analyzed and classified according to their origin. Methods for defect localization are described. This paper presents an overview of the quality control techniques used and critically evaluates their effectiveness in progressively identifying defects, seeking lessons applicable to similar large, complex projects.

WEPD003	Manufacture and Test of a Small Ceramic-insulated Nb3Sn Split Solenoid	collider, damping, linear-collider, undulator	2404
	B. Bordini, R. Maccaferri, L. Rossi, D. Tommasini CERN, Geneva
	A small split solenoid wound with high Jc Nb3Sn conductor, constituted by a 0.8 mm Rod Re-stack Process (RRP) strand, was built and tested at CERN in order to study the applicability of: ceramic wet glass braid insulation without epoxy impregnation of the magnet; a new heat treatment devised at CERN and particularly suitable for reacting RRP Nb3Sn strands. This paper briefly describes the solenoid and the experimental results obtained during 4.4 K and 1.9 K tests. The split solenoid consists of two coils (25 mm inner diameter, 51.1 mm outer diameter, 12.9 mm height). The coils were initially separately tested, in an iron mirror configuration, and then tested together in split solenoid configuration. In all the tests at 4.4 K the coils reached a current higher than 97% of their short sample limits at the first quench; in split solenoid configuration the maximum field in the coils and in the aperture were respectively 10.7 T and 12.5 T. At 1.9 K the coils had premature quenches due to self field instability despite the rather high RRR of the two coils (190 and 270). This phenomenon at 1.9 K, expected by our theory* and also confirmed by strand measurements, is discussed. *B. Bordini, E. Barzi, S. Feher, L. Rossi, and A. V. Zlobin. "Self-Field Effects in Magneto-Thermal Instabilities for Nb-Sn Strands," to be published in IEEE Trans. Appl. Supercond. 2008.

WEPD012	The LHC Continuous Cryostat Interconnections: the Organization of a Logistically Complex Worksite Requiring Strict Quality Standards and High Output	controls, cryogenics, quadrupole, alignment	2428
	P. Fessia, F. F. Bertinelli, D. Bozzini, P. Cruikshank, A. Jacquemod, W. Maan, A. Musso, L. Oberli, A. Poncet, S. Russenschuck, F. Savary, M. Struik, Z. Sulek, J.-P. G. Tock, D. Tommasini, C. Vollinger CERN, Geneva A. Grimaud ALL43, Saint-Genis-Pouilly A. Kotarba HNINP, Kraków L. Vaudaux IEG, St-Genis-Pouilly
	The interconnections of the Large Hadron Collider (LHC) continuous cryostat have been completed in autumn 2007: 1695 magnet to magnet interconnections and 224 interconnections between the continuous cryostat and the cryogenic distribution line have been closed along the 27km of the LHC. The high productivity demanded, the complexity of the interconnection sequence, the strict quality standards have required an ad hoc organization in order to steer and coordinate the activities on a worksite that was spread along the whole accelerator ring. The optimization of the intricate sequence of construction and test phases carried out by CERN staff, CERN collaborating institutes and contractors have led to the necessity of a common approach and of a very effective information flow. Specialized CERN teams have been created to deal with non standard operation to smooth the work sequences of the main assembly teams. In this paper, after having recalled the main technical challenges, we review the organizational choices that have been taken, their impact on quality and productivity and we briefly analyze the development of the worksite in term of allocated resources and production.

WEPD021	Magnetic Field Characteristics of a SIS 100 Full Size Dipole	multipole, dipole, injection, synchrotron	2452
	P. Schnizer, E. S. Fischer GSI, Darmstadt P. G. Akishin JINR, Dubna, Moscow Region R. V. Kurnyshov Electroplant, Moscow B. Schnizer TUG/ITP, Graz P. A. Shcherbakov IHEP Protvino, Protvino, Moscow Region G. Sikler, W. Walter BNG, Würzburg
	FAIR will feature two superconducting fast ramped synchrotrons. The dipole magnets for one of them, SIS 100, have been designed and prototypes were built. The properties of the magnetic field were analysed using OPERA (for DC operation) and ANSYS for dynamic calculations. Elliptic multipoles fulfilling the Laplace Equation in plane elliptic coordinates describe the field within the whole aperture consistently within a single expansion. Further circular multipoles, valid within the ellipse, can be calculated analytically from the elliptic multipoles. The advantage of this data representation is illustrated on the FEM calculation performed for SIS 100 dipoles and quadrupoles currently foreseen for the machine. The magnetic field of one of these prototypes was measured using a mole. We compare the results of the calculation to the measurement for the static as well as the dynamic mode.

WEPD026	The Special LHC Interconnections: Technologies, Organization and Quality Control	cryogenics, insertion, controls, superconducting-magnet	2464
	J.-P. G. Tock, F. F. Bertinelli, D. Bozzini, P. Cruikshank, O. Desebe, M. F. Felip-Hernando, C. Garion, A. Jacquemod, N. Kos, F. Laurent, A. Poncet, S. Russenschuck, I. Slits, L. R. Williams CERN, Geneva L. Hajduk HNINP, Krakow L. Vaudaux IEG, St-Genis-Pouilly
	In addition to the standard interconnections of the continuous cryostat of the Large Hadron Collider (LHC), there exists a variety of special ones related to specific components and assemblies, such as cryomagnets of the insertion regions, electrical feedboxes and superconducting links. Though they are less numerous, their specificities created many additional interconnection types, requiring a larger variety of assembly operations and quality control techniques, keeping very high standards of quality. Considerable flexibility and adaptability from all the teams involved (CERN staff, collaborating institutes, contractors) were the key points to ensure the success of this task. This paper first describes the special interconnections and presents the employed technologies which are adapted from the standard work. Then, the organization adopted for this non-repetitive work is described. Examples of non-conformities that were resolved are also discussed. Figures of merit in terms of quality and productivity are given and compared with standard interconnections work.

WEPD043	Orbital Welding of QRL Line in Confined Environment	cryogenics, controls, alignment, collider	2509
	E. P. Roussel Air Liquide, Sassenage P. J.D. P. Mazoyer ORBITAL, Vonnas
	AIR LIQUIDE DTA was in charge of design, manufacturing of element and installation of QRL line of CERN. The elements of this cryogenic line have been welded by orbital welding with an open weld head. A specific welding head has been developed for the project. Radial and axial clearances lead the design of the head. To install this cryogenic line, more than 15 000 orbital welds have been realized. This paper will present the technical requirements applicable to QRL line, different welding configuration, main step to qualify welding process. We will describe the results of non destructive examination: helium leak test, X-ray inspection and visual inspection.

WEPD045	Hydrogen Cryosorption on Multi Walled Carbon Nanotubes	collider, cryogenics, background, synchrotron	2515
	F. Xu, M. Barberio, P. Barone, A. Oliva, L. Papagno, V. Pirronello, R. Vasta INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza)
	We present a Temperature Programmed Desorption (TPD) study on H₂ adsorption on multiwalled carbon nanotubes (MWNT) at very low pressure (< 10^-6 Torr) and temperature (12-30 K). Our results show a hydrogen take up limit in the range of 10^-8 mol per gram depending on the adsorption temperature. We compare the MWNT cryosorption capacity with that of commonly used activated carbon and discuss the possibility of employing MWNT as cryosorber in large particle accelerators.

WEPP009	Collimator Integration and Installation Example of One Object to be Installed in the LHC	insertion, collimation, alignment, survey	2542
	K. Foraz, O. Aberle, R. W. Assmann, C. Bertone, R. Chamizo, S. Chemli, J.-P. Corso, F. Delsaux, J. L. Grenard, J. M. Jimenez, Y. Kadi, K. Kershaw, M. Lazzaroni, R. Perret, Th. Weiler CERN, Geneva J. Coupard IN2P3-CNRS, Orsay
	The collimation system is a vital part of the LHC project, protecting the accelerator against unavoidable regular and irregular beam loss. About 80 collimators will be installed in the machine before the first run. Two insertion regions are dedicated to collimation and these regions will be among the most radioactive in the LHC. The space available in the collimation regions is very restricted. It was therefore important to ensure that the 3-D integration of these areas of the LHC tunnel would allow straightforward installation of collimators and also exchange of collimators under the remote handling constraints imposed by high radiation levels. The paper describes the 3-D integration studies and verifications of the collimation regions combining the restricted space available, the dimensions of the different types of collimators and the space needed for transport and handling. The paper explains how installation has been planned and carried out taking into account the handling system and component availability.

WEPP036	DAΦNE Setup and Operation with the Crab-Waist Collision Scheme	luminosity, sextupole, injection, collider	2599
	C. Milardi, D. Alesini, M. E. Biagini, C. Biscari, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G. O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, F. Murtas, L. Pellegrino, M. A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov INFN/LNF, Frascati (Roma) N. Arnaud, D. Breton, P. Roudeau, A. Stocchi, V. Variola, B. F. Viaud LAL, Orsay S. Bettoni CERN, Geneva P. Branchini roma3, Rome M. Esposito Rome University La Sapienza, Roma I. Koop, E. B. Levichev, P. A. Piminov, D. N. Shatilov BINP SB RAS, Novosibirsk K. Ohmi KEK, Ibaraki E. Paoloni University of Pisa and INFN, Pisa M. Schioppa INFN Gruppo di Cosenza, Arcavacata di Rende (Cosenza) V. V. Smaluk BINP, Novosibirsk P. Valente INFN-Roma, Roma
	In the second half of 2007 a major upgrade has been implemented on the Frascati DAΦNE collider in order to test the novel idea of Crab Waist collisions. New vacuum chambers and permanent quadrupole magnets have been designed, fabricated and installed to realize the new configuration. At the same time the performances of relevant hardware components, such as fast injection kickers and shielded bellows have been improved relying on new design concepts. The collider has been successfully commissioned in this new configuration. The paper describes the new layout as well as several experimental results about linear and non-linear optics setup and optimization, damping of beam instabilities and discusses the obtained luminosity performances.

WEPP041	High-current Effects in the PEP-II Storage Rings	kicker, feedback, impedance, ion	2611
	U. Wienands, W. X. Cheng, W. S. Colocho, S. DeBarger, F.-J. Decker, S. Ecklund, A. S. Fisher, D. Kharakh, A. Krasnykh, A. Novokhatski, M. K. Sullivan SLAC, Menlo Park, California
	High beam currents, 2A(HER) & 3A(LER), in PEP-II has been a challenge for the vacuum system. For the ~1 cm long bunches peak currents reach 50 A. Thus modest impedances can give rise to voltage spikes and discharges. A weakness was uncovered during Run 6: rf seals at the "flex flanges" that join the HER arc dipole and quadrupole chambers became a source of an increasing number of HER beam aborts. Vacuum activity was seen and thermal sensors on these flanges saw temperature spikes. Inspection of the seals found arcing and melting, prompting us to replace all of these seals with an improved design using Inconel instead of GlidCop fingers. We believe the GlidCop fingers do not maintain elasticity and hence can not follow chamber motion due to thermal effects. The Run 7 startup confirmed the success of this repair. However, high bunch current in the LER caused breakdown in a LER kicker. This limited the LER bunch current to about 1 mA. Inspection revealed damage to one of the recently added Macor pins that help support the electrodes. Failure analysis revealed heating of the pin & post-facto modeling shows high fields coming from a combination of HOM impedance and high peak currents.

WEPP056	Aperture Restriction Localisation in the LHC Arcs using an RF Mole and the LHC Beam Position Measurement System	dipole, monitoring, radio-frequency, quadrupole	2644
	O. R. Jones, J. Albertone, S. Bartolome-Jimenez, C. Boccard, T. Bogey, P. B. Borowiec, E. Calvo, F. Caspers, M. Gasior, J. L. Gonzalez, B. Jenninger, L. K. Jensen, T. Kroyer, S. Weisz CERN, Geneva
	Ensuring that the two 27km beam pipes of the LHC do not contain aperture restrictions is of utmost importance. Most of the ring is composed of continuous cryostats, so any intervention to remove aperture restrictions when the machine is at its operating temperature of 1.9K will require a substantial amount of time. On warming-up the first cooled sector, several of the sliding contacts which provide electrical continuity for the image current between successive sections of the vacuum chamber were found to have buckled into the beam pipe. This led to a search for a technique to verify the integrity of a complete LHC arc (~3km) before any subsequent cool-down. In this paper the successful results from using a polycarbonate ball fitted with a 40MHz RF transmitter will be presented. Propulsion of the ball is achieved by sucking filtered air through the entire arc, while its progress is traced every 54m via the LHC beam position measurement system which is auto-triggered by the RF transmitter on passage of the ball. Reflectometry at frequencies in the 4-8 GHz range can cover the gaps between beam position monitors and could therefore be used to localise a ball blocked by an obstacle.

WEPP064	Apertures in the LHC Beam Dump System and Beam Losses during Beam Abort	extraction, kicker, simulation, dumping	2665
	T. Kramer, B. Goddard, M. Gyr, A. Koschik, J. A. Uythoven, Th. Weiler CERN, Geneva
	The LHC beam dump system is used to dispose accelerated protons and ions in a wide energy range from 450 GeV up to 7 TeV. An abort gap of 3 microseconds is foreseen to avoid sweeping particles through the ring aperture. This paper gives a brief overview of the critical apertures in the extraction region and the two beam dump lines, and presents MAD-X tracking studies made to investigate the impact of particles swept through the aperture due to extraction kicker failures or spurious particles within the abort gap.

WEPP066	Results from the LHC Beam Dump Reliability Run	dumping, kicker, extraction, injection	2671
	J. A. Uythoven, A. Antoine, E. Carlier, F. Castronuovo, L. Ducimetière, E. Gallet, B. Goddard, N. Magnin, H. Verhagen CERN, Geneva
	The LHC Beam Dumping System is one of the vital elements of the LHC Machine Protection System and has to operate reliably every time a beam dump request is made. Detailed dependability calculations have been made, resulting in expected rates for the different system failure modes. A 'reliability run' of the system, installed in its final configuration in the LHC, has been made to discover infant mortality problems and to compare the occurrence of the measured failure modes with their calculations.

WEPP077	The XFEL Laser Heater	laser, undulator, electron, gun	2695
	V. G. Ziemann, G. Angelova UU/ISV, Uppsala M. Dohlus, Y. A. Kot DESY, Hamburg
	The high-brilliance photo-cathode gun foreseen for the X-FEL will provide beams with extremely small momentum spread that will make the beam susceptible to micro-bunching instabilities which will spoil SASE operation. It is therefore desirable to increase the momentum spread to a level that prevents these instabilties but still is compatible with SASE operation. The laser heater will achive this by superimposing a transversely polarized laser and the electron beam in a properly tuned undulator, thereby producing a momentum modulation that is smeared out in a dogleg chicane to obtain the desired momentum spread increase. We present the initial design and layout of the laser heater system for the X-FEL in Hamburg.

WEPP078	PHIL: a Test Beam line at LAL	gun, laser, simulation, emittance	2698
	R. Roux, M. Bernard, G. Bienvenu, S. Cavalier, M. Jore, B. Leblond, B. M. Mercier, B. Mouton, C. P. Prevost, V. Variola LAL, Orsay
	For 2004, in the framework of a European contract, LAL is in charge of the construction of one photo-injector for the drive beam linac of the CLIC Test Facility 3 at CERN. This contract together with national funds allowed LAL to build a test accelerator with the same photo-injector as for CTF3. The goal is to undergo experiments on advanced RF guns but a part of the beam time will be also shared with users of the electron beam. So far, the construction of this accelerator at LAL was very much delayed because of the legal obligation to upgrade the radiation shielding in agreement with the actual radiation safety thresholds. The required civil engineering is now finished and the installation of the components is under way. We will first present a design of the accelerator and few dynamic simulation results. Finally we will give a status of the accelerator construction up to date.

WEPP091	Injector Upgrade for the S-DALINAC	linac, coupling, acceleration, electron	2731
	T. Kuerzeder, A. Araz, M. Brunken, J. Conrad, R. Eichhorn, H.-D. Gräf, M. Hertling, F. Hug, M. Konrad, M. Platz, A. Richter, S. Sievers, T. Weilbach TU Darmstadt, Darmstadt W. Ackermann, W. F.O. Müller, B. Steiner, T. Weiland TEMF, Darmstadt J. D. Fuerst ANL, Argonne, Illinois
	Since 1991 the superconducting Darmstadt linear accelerator S-DALINAC provides an electron beam of up to 130 MeV for nuclear and astrophysical experiments. Currently its injector delivers beams of up to 10 MeV with a current of up to 60 μA. The upgrade aims to increase both parameters to 14 MeV and 150 μA in order to allow more demanding astrophysical experiments. Therefore, a modified cryostat module equipped with two new cavities is required. Due to an increase in RF power to 2 kW the old coaxial RF input couplers, being designed for a maximum power of 500 W, have to be replaced by new waveguide couplers. We review the design principles and report on the fabrication of the coupler and the whole module.

WEPP099	Results from Atomic Layer Deposition and Tunneling Spectroscopy for Superconducting RF Cavities	scattering, superconductivity, coupling, electron	2749
	J. Norem, J. W. Elam, M. J. Pellin ANL, Argonne, Illinois C. Z. Antoine CEA, Gif-sur-Yvette L. Cooley Fermilab, Batavia, Illinois J. F. Moore MassThink LLC, Naperville, IL Th. Proslier, J. Zasadzinski IIT, Chicago, Illinois
	Atomic Layer Deposition is a process that synthesizes materials in successive monolayers, at rates on the order of 1 micron/hour. We have been using this technique at Argonne as a possible way to improve both superconducting rf (SCRF) and normal rf structure performance. Initial experiments have led to a new model of high field Q-slope and new ways of controlling SCRF surfaces, as well as suggesting ways to significantly improve the operating gradients of both superconducting and normal structures. We have also been testing this technique in superconducting structures. Initial measurements show significant improvement over “cavity-grade” Nb samples.

WEPP106	High-gradient Experiments with Narrow Waveguides	klystron, controls	2758
	K. Yokoyama, S. Fukuda, Y. Higashi, T. Higo, N. K. Kudo, S. Matsumoto KEK, Ibaraki
	High-gradient RF breakdown studies are presently being conducted at Nextef. To study the characteristics of different materials on high-field RF breakdown, we have performed experiments by using a reduced cross-sectional waveguide that has a field of approximately 200MV/m at an RF power of 100MW. A description of the high-gradient testing of copper and stainless-steel waveguides is reported.

WEPP131	RF-breakdown Experiments at the CTF3 Two-beam Test-stand	ion, electron, dipole, extraction	2800
	M. Johnson, T. J.C. Ekelöf, R. J.M. Y. Ruber, V. G. Ziemann UU/ISV, Uppsala H.-H. Braun CERN, Geneva
	The Two-beam Test-stand (TBTS) in the CLIC Test Facility CTF3 offers unique possibilities to conduct RF-breakdown related experiments on the accelerating structures and the power extraction and transfer structures with beam. We report on the set-up of two such experiments, one for the measurement of the transverse kick and the other for the measurement of positive ion currents. The purpose of the transverse kick measurements is to determine the effects of a RF-breakdown event on the beam. Five BPMs in the TBTS will be used to study the trajectory of a pulse train after a RF-breakdown event, with important implications for the operation of CLIC. Ion currents ejected from accelerating structures during RF-breakdown events have already been observed at the 30 GHz test stand at the present test facility. Results and their implications for RF-breakdown physics are presented, as well as plans for similar measurements at the TBTS.

WEPP137	Accelerating and Transporting Attosecond and Femtosecond Bunches of Electrons	electron, laser, cathode, space-charge	2815
	V. A. Papadichev LPI, Moscow
	Dynamics of short bunches of electrons obtained upon field emission in a quasi-static electric field and a variable electric field of a laser has been studied. The equation of longitudinal motion of electrons was numerically integrated. Emitted electrons are accelerated by quasi-static potential applied to the spike and this drastically reduces initial energy spread in the bunch preventing its fast elongation. When the forces of space charge have little effect, grouping part of the beam due to velocity spread acquired in the laser field permits to obtain bunches of about 200-as duration when using a carbon dioxide laser and about 6-as with a neodymium laser. Analytical models were used to evaluate the influence of the space charge of the bunch on the longitudinal motion of electrons in it. It has been shown that the proper choice of the intensities of both fields can cancel such an influence. There have been considered methods of lateral focusing of the beam taking into account possible initial angular divergence and space charge effects. Such electron bunches could be used directly in experiments or for generation of short pulses of coherent UV- and X-ray radiation. V. A. Papadichev, Femtosecond and Attosecond Bunches of Electrons Upon Field Emission in a Combined Quasi-static and Laser Electric Field, submitted to this Conference.

WEPP139	The CTF3 Two-beam Test-stand Installation and Experimental Program	dipole, acceleration, quadrupole, diagnostics	2821
	V. G. Ziemann, T. J.C. Ekelöf, M. Johnson, R. J.M. Y. Ruber UU/ISV, Uppsala H.-H. Braun, S. Doebert, G. Geschonke, G. Riddone, J. P.H. Sladen, I. Syratchev, W. Wuensch CERN, Geneva
	The Two-beam Test-stand in CTF3 will be used to investigate the power-generation and accelerating structures for the Compact Linear Collider CLIC. We report on its design and construction which was recently completed and discuss the imminent commissioning phase as well as the following experimental program that initially will be devoted to the test of power generation structures in the drive-beam.

WEPP142	Simulation of and Progress towards a Micron-scale Laser-powered Dielectric Electron Source	simulation, laser, coupling, resonance	2827
	G. Travish, J. B. Rosenzweig, J. Xu UCLA, Los Angeles, California S. Boucher RadiaBeam, Marina del Rey R. B. Yoder Manhattan College, Riverdale, New York
	A dielectric, slab-symmetric structure for generating and accelerating low-energy electrons has been under study for the past two years. The resonant device is driven by a side-coupled laser and is configured to maintain field provide necessary for synchronous acceleration and focusing of nonrelativistic particles. Intended applications of the structure include the production of radiation for medical treatments, imaging, and industrial uses. The details of the structure geometry and its resonant properties have been studied with 2D and 3D electromagnetic codes, the results of which are present here.

WEPP151	Metallic Photonic Band Gap Accelerator Structure Experiments and Design	damping, radiation, 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.

WEPP161	Preliminary Experiments on a Fluidised Powder Target	target, factory, recirculation, collider	2862
	O. Caretta, C. J. Densham STFC/RAL, Chilton, Didcot, Oxon T. W. Davies Exeter University, Exeter, Devon R. M. Woods Gericke LTD, Ashton-under-Lyne
	In order to achieve higher resolutions the next generation of accelerator facilities is designed to operate with beam powers orders of magnitude higher than that handled by the current technology. So it is believed that the existing target and beam dump designs will be unsuitable to survive beam interactions depositing powers in the order of several megawatts. Good target design is important for the physics yield from experiments and crucial to the reliable operation of the facility. Furthermore the choice of target is strongly associated with the safety and cost of design (i.e., economic viability) of the entire facility. This article proposes a new target technology based on fluidised powder believed to be suitable for application at higher beam powers whilst avoiding some of the problems associated with other technologies. A conceptual system design for the application of the fluidised powder target to the requirements of a future neutrino facility, is presented. The preliminary experimental results presented, show the effect of some of the parameters which are expected to determine the performance, physics yields and reliability of operation of the new powder system.

WEPP165	GdfidL Simulations of International Linear Collider Candidate Collimator Assemblies	simulation, linear-collider, collider, insertion	2874
	J. D.A. Smith Cockcroft Institute, Warrington, Cheshire
	Collimator performance is critical to the successful operation of any collider. Building on previous GdfidL simulations of collimator jaws, this paper describes simulations where STL files of the complete assembly are investigated and wakefield performance is determined and optimised.

WEPP166	Comparison of Collimator Wakefields Formulae	dipole, impedance, quadrupole, electron	2877
	A. M. Toader, R. J. Barlow UMAN, Manchester
	There is an extensive literature on transverse wakefield kick factors in collimators. We present a compendium of the formulae and discuss their agreement and disagreement with each other and with experimental results.

WEPP168	Mechanical Design of Collimators for the ILC	radiation, 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.

THXM03	Status of the European HOM Damped Normal Conducting Cavity	impedance, brilliance, simulation, damping	2932
	E. Weihreter BESSY GmbH, Berlin
	Cavities with damped higher order modes (HOMs) are an essential ingredient for state of the art storage ring based high brilliance synchrotron radiation sources to avoid degradation of the beam quality due to coupled bunch instabilities. Starting with a review of the concepts of existing HOM damped cavities the status of a normal conducting 500 MHz cavity is presented which has been developed for low and medium energy high brilliance synchrotron light sources within the frame of an EC funded collaboration. The results of numerical simulations and of low power impedance measurements are reported together with conceptional improvements, expected performance, and first operational achievements in the Metrology Light Source in Berlin.
	Slides

THPC017	Optimisation of a Beam Transfer FODO Line	quadrupole, optics, emittance, beam-losses	3014
	J. B. Jeanneret, H.-H. Braun CERN, Geneva
	With in view the design of the CLIC long transfer lines, we developed a formal approach for the optimisation of a straight FODO line. Optimum phase advance and cell length depending on beam parameters are derived for power consumption, overall cost and sensitivity to quadrupole misalignment.

THPC102	Image Simulations on the ISIS Synchrotron	simulation, closed-orbit, lattice, dipole	3215
	B. G. Pine, C. M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a loss-limited 50 Hz proton synchrotron, which accelerates ~3·10¹³ ppp from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. A significant proportion of beam loss is attributable to space charge effects. One such effect is the image field which forms in the beam pipe. Off-centre beams resulting from closed orbit errors generate fields, which can perturb the beam and cause loss. Of particular interest on ISIS is the rectangular, varying aperture, vacuum vessel, as compared with the more usual constant aperture circular or elliptical geometries. A new 2D space charge code, Set, was developed to study these effects. The code simulates the effects of space charge using a 2D particle-in-cell model of the beam distribution, including an appropriate treatment of the rectangular beam pipe, and details of the ISIS lattice. The effects of images on closed orbits, driving terms, and the evolution of beam distributions at ISIS operational intensities were explored.

THPC105	Self-consistent Transverse Dynamics and Interbunch Energy Exchange in Dielectric Loaded Wakefield Accelerating Structures	focusing, electron, acceleration, transverse-dynamics	3224
	I. L. Sheynman LETI, Saint-Petersburg A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio
	The self-consistent transverse dynamics of high current relativistic electron beams used for generating wakefields in dielectric loaded structures is investigated. The primary application of this work is to multi-bunch wakefield acceleration. The maximum distance the high current beam can travel through the structure in the absence of focusing without experiencing beam breakup and the energy transferred to the accelerated electron bunch will be presented. We consider both ramped and uniform charge distributions in the sequence of high current drive bunches. The ramped drive charge distribution is compared to the case of a uniform charge distribution in terms of the requirements for the beam focusing system and the effectiveness of the energy transfer to the accelerated electron bunch.

THPC107	Beam Dynamical Issues of the KEK All-ion Accelerator	ion, injection, electron, acceleration	3227
	K. Takayama, T. Adachi, E. Nakamura, H. Someya KEK, Ibaraki
	R&D works to realize an all-ion accelerator (AIA)* capable of accelerating all species of ions with any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006*, are going on at KEK. The KEK AIA, which is a modification of the existing KEK 500 MeV Booster Ring of a rapid cycle synchrotron, may be an injector-free accelerator. An ion beam from the high-voltage terminal of 200 kV is directly injected into the accelerator ring. Several key issues associated with the low energy injection must be addressed. Space-charge limited current due to a small relativistic b and a short life-time due to scattering with the residual molecules and eddy-current induced magnetic fields associated with guide-fields ramping from a low field level are among them. Careful considerations on them suggest that there are significant constrains on the operational performance and gives achievable beam parameters assuming the present parameters of the KEK AIA. K. Takayama, Y. Arakida, T. Iwashita, Y. S himosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007). **K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).

THPC108	Observation of Bound States of Particles in the Storage Ring	storage-ring, electron, synchrotron, radiation	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.

THPC120	Conceptual Design and Performance Estimation of The TPS Fast Orbit Feedback System	feedback, power-supply, controls, closed-orbit	3263
	P. C. Chiu, J. Chen, K. T. Hsu, K. H. Hu, C. H. Kuo NSRRC, Hsinchu
	A 3 GeV Synchrotron (TPS) is proposed in Taiwan. Its storage ring consists of 24 double-bend cells with 6-fold symmetry and the circumference is 518.4m. The report presents the initial design of the fast orbit feedback system (FOFB) for TPS. The system uses 168 BPMs and 168 correct magnets to stabilize global closed orbit at 10 kHz updated rate. The different subsystems are modeled: the BPM systems, the corrector magnet, vacuum chamber, and etc. The latency of the communication and computation is also studied. The preliminary calculation on the stability performance for the orbit feedback system is presented in the report. The FOFB is expected to achieve a submicron stability of the electron beam working at a bandwidth of at least 100 Hz.

THPC121	LHC Transverse Feedback System and its Hardware Commissioning	kicker, feedback, injection, damping	3266
	W. Höfle, P. Baudrenghien, F. Killing, Y. A. Kojevnikov, G. Kotzian, R. Louwerse, E. Montesinos, V. Rossi, M. Schokker, E. Thepenier, D. Valuch CERN, Geneva E. V. Gorbachev, N. I. Lebedev, A. A. Makarov, S. Rubtsun, V. Zhabitsky JINR, Dubna, Moscow Region
	A powerful transverse feedback system ('damper') has been installed in LHC. It will stabilise coupled bunch instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The transverse damper can also be used as an exciter for purposes of abort gap cleaning or tune measurement. The power and low-level systems layout are described along with results from the hardware commissioning. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control. Requirements and first measurements of the performance of the low-level system are summarized. The chosen approach for the low-level system using advanced FPGA technology is very flexible allowing implementation of future upgrades of the signal processing without changing the hardware.

THPC124	The Manufacturing and Tests of The New Vertical Feedback Stripline at Soleil	feedback, impedance, simulation, kicker	3275
	C. Mariette, J.-C. Denard, R. Nagaoka SOLEIL, Gif-sur-Yvette
	This paper describes the development of the kicker striplines for the bunch-by-bunch transverse instability feedback system at Soleil. A careful design of the striplines and of their vacuum feedthroughs was aimed at maximizing the effectiveness of the excitation power and minimizing the power taken from the beam. The excitation effectiveness improves with the shunt impedance. But, simultaneously, the beam impedance should be made as small as possible. We also found useful to estimate the temperature of the feedthroughs at high beam currents, especially on the ceramic-to-metal seals. We also report on the difficulties encountered with obtaining good feedthroughs.

THPC139	Properties of X-ray Beam Position Monitors at the Swiss Light Source	feedback, photon, electron, controls	3312
	T. Wehrli, M. Böge, J. Krempasky, E. D. van Garderen PSI, Villigen
	Tungsten blade type X-ray beam position monitors (X-BPMs) are widely used at the SLS to stabilize the photon beam position at the the micron level. Various slow (~0.5 Hz) photon beam position feedbacks (SPBPFs) being an integral part of the global orbit feedback system have been in operation for several years. They are solely based on one X-BPM reading assuming that the photon beam movement is dominated by angle changes of the electron beam. This paper reports on the operation of the first SPBPF using two X-BPMs. This allows the separation of positional and angular variations of the electron beam, which is of special importance for the recently commissioned PolLux dipole beamline, as it is mostly sensitive to position changes. Correlations between the electron beam movement and the X-BPM readings are extensively analyzed in order to disentangle systematic errors of the position determination and real orbit motion. Methods are presented on how to recognize and correct or even avoid large systematic errors of the X-BPMs. With this knowledge, the demanding requirements on X-BPM accuracy in case of a SPBPF utilizing two X-BPMs could be fulfilled for the first time at the SLS.

THPC140	The Performance of a Fast Closed Orbit Feedback System with Combined Fast and Slow Correctors	feedback, closed-orbit, power-supply, simulation	3315
	L.-H. Yu, S. Krinsky, O. Singh, F. J. Willeke BNL, Upton, Long Island, New York
	For NSLSII closed orbit feedback system, in order to reduce the noise caused by the step changes of the power supplies in the feedback system, the angular kick corresponding to the last bit of the power supplies for the fast correctors must be smaller than 3 nrad. On the other hand, in order to carry out closed orbit alignment or orbit correction after a long term drift, we need strong correctors with 0.8 mrad kick strength. In order to avoid the requirement of correctors with both large strength and very small minimum step size, we consider separate sets of slow correctors with large strength and fast correctors with smaller maximum strength. In order to avoid fast and slow feedback systems working in parallel, and avoid the possible interaction between two feedback systems, we consider the possibility of using only one fast feedback system with slow correctors periodically removing the DC components of the fast correctors so that the DC components in fast feedback system would not accumulate to reach saturation even after a large long term drift of the closed orbit motion. We report on simulation of the performance of this combined system for NSLSII in this paper. * NSLSII Preliminary Design Report (2007)

THPP002	EMMA RF Cavity Design and Prototype Testing at Daresbury	impedance, acceleration, kicker, electron	3374
	C. D. Beard, P. A. Corlett, D. M. Dykes, P. Goudket, C. Hill, P. A. McIntosh, A. J. Moss, J. F. Orrett, J. H.P. Rogers, A. E. Wheelhouse, E. Wooldridge STFC/DL/ASTeC, Daresbury, Warrington, Cheshire N. Bliss STFC/DL, Daresbury, Warrington, Cheshire A. E. Bogle, T. L. Grimm, A. A. Kolka Niowave, Inc., Lansing, Michigan
	At PAC’07 we discussed the design of a prototype cavity to be used on EMMA. EMMA is a prototype non-scalling FFAG. It will contain 19 RF cavities operating at 1.3 GHz with a baseline accelerating voltage of 120 kV. A prototype cavity has been manufactured by Niowave, Inc. and we will present a discussion of its RF and mechanical design. This cavity was put through low power tests, to determine frequency, tuning range, shunt impedance and Q of the cavity; and high power tests, to confirm power handling ability, when it arrived at Daresbury Laboratory this spring. The results of these tests were compared to the simulations and a bead pull was carried out to obtain the field profile. The cavities for EMMA are likely to be powered by IOTs, these will be used for the high power tests, which will demonstrate cavity operation to the required maximum of 180 kV. E. Wooldridge et al. "RF Cavity Development for FFAG Application on ERLP at Daresbury," Proceedings of PAC’07, Albuquerque, NM (2007).

THPP007	Six-sector FFAG Ring to Demonstrate Bunch Rotation for PRISM	simulation, closed-orbit, target, injection	3389
	A. Sato, M. Aoki, S. Araki, Y. Arimoto, Y. Eguchi, K. Hirota, I. Itahashi, Y. Kuno, Y. Kuriyama, Y. Nakanishi, M. Y. Yoshida Osaka University, Osaka Y. Iwashita Kyoto ICR, Uji, Kyoto A. Kurup Imperial College of Science and Technology, Department of Physics, London Y. Mori KURRI, Osaka C. Ohmori KEK, Ibaraki
	A monochromatic muon beam is one of the most important requirements to improve a sensitivity of mu-e conversion experiments. In the PRISM project, which searches for mu-e conversion at a sensitivity of BR~10^-18, makes such muon beams by using a bunch rotation technique in an FFAG ring. To demonstrate the bunch rotation, a FFAG ring has been constructed in RCNP, Osaka. The ring has six FFAG magnets and one RF cavity. Alpha particles from a radioactive isotope ²⁴¹Am will circulate in the ring for the demonstration of bunch rotation.

THPP019	Adjustment of a New Pre-stripping Section the Multicharge Ion Linear Accelerator (MILAC)	ion, simulation, focusing, acceleration	3410
	O. F. Dyachenko, V. A. Bomko, Ye. V. Ivakhno, A. P. Kobets, V. I. Misjura, V. V. Mytrochenko, A. V. Zabotin, B. V. Zajtsev NSC/KIPT, Kharkov
	In the Kharkov Institute of Physics and Technology the works on commissioning of a new prestripping section (A/q = 4), intend for accelerating a high current beam of light ions from 30 keV/u to 975 keV/u come to the end. Results of final tuning of irregular interdigital accelerating structure with alternating phase focusing and stepped changing the synchronous phase along the focusing period are presented. Process of preliminary adjustment of structure by means of traditional developed earlier methods: the additional current-carrying stems and the end resonant tuning elements (ERTEs) is described. New effective inductance-capacitor tuning devices as rods located on the drift tube side, opposite to their holders (�contrivance�) are developed and their use in real structure is shown. �Contrivances� have proved as the effective element of tuning locally influencing value of an electric field in the nearest gaps and lowering resonant frequency without noticeable worsening of electrodynamic characteristics of resonant system.

THPP025	Fabrication Status of the PEFP DTL II	alignment, linac, proton, laser	3425
	H. S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, B.-S. Park KAERI, Daejon
	The DTL II as a main part of the PEFP proton linac is under development. Following the DTL I which accelerates the proton beam up to 20 MeV, DTL II increases the proton energy from 20 MeV to 100 MeV. The DTL II consists of 7 tanks and each tank is composed of 3 sections whose length is about 2.2 m. The tank is made of seamless carbon steel and inside surface is electroplated with copper. Each drift tube contains an electroquadrupole magnet which is made of hollow conductor and iron yoke with epoxy molding. The status of development and test results of the fabricated parts are reported in this paper.

THPP049	Status of Electron Cooler Design for HESR	electron, antiproton, diagnostics, target	3473
	B. Gålnander, T. Bergmark, S. Johnson, T. Johnson, T. Lofnes, G. Norman, T. Peterson, K. Rathsman, D. Reistad TSL, Uppsala H. Danared MSL, Stockholm
	The HESR-ring of the future FAIR-facility at GSI will include both electron cooling and stochastic cooling in order to achieve the demanding beam parameters required by the PANDA experiment. The high-energy electron cooler will cool antiprotons in the energy range 0.8 GeV to 8 GeV. The design is based on an electrostatic accelerator and shall not exclude a further upgrade to the full energy of HESR, 14.1 GeV. The paper will discuss prototype tests of critical components and recent development in the design including the high-voltage tank, electron gun and collector, magnet system, electron beam diagnostics and the magnetic field measuring system.

THPP051	Stochastic Cooling in the Framework of the FAIR Project at GSI	pick-up, antiproton, storage-ring, cryogenics	3479
	F. Nolden, A. Dolinskii, B. Franzke, U. Jandewerth, T. Katayama, C. Peschke, P. Petri, M. Steck GSI, Darmstadt D. Möhl CERN, Geneva
	Stochastic cooling at FAIR will be one of the instruments to get cooled beams of rare isotopes and antiprotons for high resolution experiments. Stochastic cooling systems will be installed in the CR and RESR storage rings. The Collector Ring CR is a dedicated storage ring for the first step cooling of antiproton beams (3 GeV or β=0.97) produced at the antiproton production target, and of radioactive beams (740 MeV/u or β=0.83) prepared in the Super Fragment Separator. The pick-up and kicker systems have designs which allow very efficient cooling for both particle velocities. There will be different ring optical settings for optimum cooling of antiprotons or rare isotopes. Whereas the next cooling step for rare isotopes will be electron cooling, antiprotons will be accumulated in the RESR using a similar accumulation scheme which was formerly applied at the AA at CERN. The paper presents the CR and RESR system layouts and new hardware developments.

THPP071	Construction of Six-sector FFAG Ring for Muon Phase Rotation	power-supply, multipole, alignment, injection	3524
	Y. Arimoto, M. Aoki, S. Araki, Y. Eguchi, K. Hirota, I. Hossain, I. Itahashi, Y. Kuno, Y. Kuriyama, Y. Nakanishi, A. Sato, M. Y. Yoshida Osaka University, Osaka Y. Iwashita Kyoto ICR, Uji, Kyoto A. Kurup Imperial College of Science and Technology, Department of Physics, London Y. Mori KURRI, Osaka C. Ohmori KEK, Ibaraki T. Oki Tsukuba University, Ibaraki
	PRISM is a next-generation of muon source which provides high purity, high intense and high brightness beam. In PRISM, a PRISM-FFAG is one of key section which make a muon beam narrow energy width by using phase rotation technique. To demonstrate the phase rotation, a six-cell FFAG ring has been constructed; the ring consists of full size of scaling-FFAG magnets and a high gradient rf cavity. The experiment is achieved by injecting alpha particles from a radioisotope source as a beam. Construction of the ring has been started from September, 2007; beam duct has been designed and installed, the six FFAG magnets has been aligned, etc. In this paper, we will present the design of the ring and the construction (alignment, etc) from engineering point of view.

THPP078	IFMIF-EVEDA RFQ Design	rfq, coupling, simulation, beam-losses	3542
	A. Pisent, M. Comunian, E. Fagotti, A. Palmieri, P. A. Posocco, C. Roncolato INFN/LNL, Legnaro, Padova F. Grespan Università degli Studi di Milano, Milano A. Pepato INFN- Sez. di Padova, Padova
	The RFQ of IFMIF-EVEDA project is characterized by very challenging specifications, with 125 mA of deuteron accelerated up to 5 MeV. After the long period of conceptual and comprehensive design of IFMIF accelerator, the decision of the construction of its low energy part has implied a new analysis of the RFQ design. In particular the beam dynamics design has been optimized, with a consistent reduction of the structure length and power consumption, and improvement of the performances in terms of beam losses. The resonator, of four vanes kind, has been designed taking advantage of the theoretical background and experimental experience gained in Europe with IPHI and TRASCO projects. The mechanical design has been analysed considering different approaches, involving vacuum brazing, laser or e'beam welding.

THPP093	Conceptual Design of the PEFP Beam Line	target, proton, linac, shielding	3581
	I.-S. Hong, Y.-S. Cho, B. H. Choi, B. Chung, J.-H. Jang, H. S. Kim, K. R. Kim, H.-J. Kwon, B.-S. Park, S. P. Yun KAERI, Daejon
	In the Proton Engineering Frontier Project (PEFP), 20MeV and 100MeV proton beams from a 100MeV proton liner accelerator will be supplied to users for proton beam applications. Switch magnets will share the beam to three directions, two fixed beam lines and one AC magnet. The two fixed beam lines will be used for isotope production and power semiconductor production. An AC magnet will distribute the beams to three targets simultaneously. To provide flexibilities of irradiation conditions for users from many application fields, we designed beam lines to the targets with wide or focused, external or in-vacuum, and horizontal or vertical beams. As far as possible we designed the simple beam lines to reduce the construction cost. The details of the beam line conceptual design will be reported.

THPP107	Lifetime Comparisons of Single and Double Layered HBC-Foils using 3.2MeV Ne⁺ Ion Beam	ion, target, radiation, 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.

THPP112	Leakage Field of Septum Magnets of 3 GeV RCS at J-PARC	septum, extraction, proton, injection	3626
	M. Yoshimoto, H. Hotchi, J. Kamiya, M. Kinsho, M. Kuramochi, P. K. Saha, T. Takayanagi, T. Togashi, T. Ueno, M. Watanabe JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken H. Harada Hiroshima University, Graduate School of Science, Higashi-Hiroshima
	Septum magnets are installed in RCS (Rapid cycling Synchrotron) at J-PARC for the beam injection and extraction. In order to realize MW beam in the RCS ring and reduce the beam loss during the beam injection and extraction, the septum magnets have large physical aperture and are operated in DC. Thus there are high magnetic fields in the gaps during the acceleration, but the leakage fields are nevertheless suppressed down to a few Gauss to suppress the closed orbit distortion. In order to reduce the magnetic leakage field from the septa at beam orbit in the RCS ring, the silicon steel sheets are set for magnetic shield. In addition a few ring vacuum chambers are made by the magnetic stainless steel. Up to now, the development and field measurement of the septum magnets has been finished, and the beam commissioning of the RCS are carried out. In this presentation, the field measurements of the septum magnets are summarized and the influences of the leakage field upon the beam orbit are reported.

THPP137	Development of Vacuum Components for XFEL/SPring-8	undulator, ion, target, cathode	3682
	T. Bizen RIKEN/SPring-8, Hyogo
	Several new vacuum components have been developed for the XFEL/SPring-8 project. Vacuum waveguide flanges for C-band and S-band were successfully developed. These flanges provide both RF seal and vacuum seal. This seal mechanism can make vacuum seal even with a scratched gasket. A solid-lubricated clean bolt was developed for C-band and S-band flanges to avoid organic dust pollution that induce multipactor. New vacuum flange for accelerator beam line can use three types of gasket. A small RF contact for 28 mm inside diameter bellows was developed. This unfixed RF contact can move freely in all directions and displaced large.

THPP138	Achievement and Evaluation of the Beam Vacuum Performance of the LHC Long Straight Sections	instrumentation, ion, insertion, proton	3685
	G. Bregliozzi, V. Baglin, S. Blanchard, J. Hansen, J. M. Jimenez, K. Weiss CERN, Geneva
	The bake-out and activation of the 6 km Long Straight Sections (LSS) of the Large Hadron Collider (LHC) is in its final step. After bake-out and activation of the NEG coating, the average ultimate pressure, over more than one hundred vacuum sectors, is below 10^-11 mbar. Therefore, the nominal requirement for the four experimental insertions is guaranteed. The nominal performances are also ensured for all the other insertions where collimators, RF cavities and beam dumping systems are present. The main difficulties encountered during the bake-out and activation of NEG coated chambers of the LSS vacuum sectors will be presented and discussed. In particular, the acceptance test and the limiting factors of the reached ultimate pressures will be addressed. Furthermore, the influence on the ultimate pressures of the beam vacuum elements (collimators, beam instrumentation, etc.) will be discussed. Finally, preliminary results obtained from a laboratory NEG pilot sector dedicated to the quality control of the LHC beam vacuum and to the evaluation of the NEG performance will be presented.

THPP139	Stainless Steel Vacuum Chambers for the SSRF Storage Ring	storage-ring, synchrotron, synchrotron-radiation, 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.

THPP140	First Experience on NEG Coated Chambers at the Australian Synchrotron Light Source	synchrotron, storage-ring, insertion, insertion-device	3690
	P. Manini, A. Conte, S. Raimondi SAES Getters S.p. A., Lainate B. Mountford ASP, Clayton, Victoria
	The Australian Synchrotron, a 3 GeV third generation Light Source saw its first light in 2006. At full capacity it will house more than 30 photon beam lines providing state of the art facilities to support fundamental and applied research to the Australian scientific community. In the regional context, the Australian Synchrotron will also effectively complement the lower energy synchrotrons in Singapore (0,8 Gev) and Taiwan (1.5 GeV). The vacuum system of the storage ring, 216 m circumference, includes ion pumps and NEG cartridge pumps. Two NEG coated, ESRF style, aluminium Insertion Devices, each 2,5 m long, have been also installed in the storage ring to boost machine parameters and broaden the spectrum of wavelength available for experiments. Preliminary vacuum results obtained during conditioning and initial operation of the Insertion Devices are reported and compared to uncoated chambers. These results confirm the effectiveness of the NEG coating technology in reducing pressure build up inside conductance limited narrow chambers. Technological issues related to the chambers preparation, film deposition, quality control and characterization will be also discussed.

THPP141	Test of a NEG Coated Copper Dipole Vacuum Chamber	dipole, storage-ring, synchrotron, photon	3693
	E. J. Wallén, M. Berglund, A. Hansson MAX-lab, Lund R. Kersevan ESRF, Grenoble
	The paper reports about a test carried out at the 1.5 GeV storage ring MAX II where a standard dipole chamber made of stainless steel was replaced by a NEG coated chamber made of copper. The standard MAX II stainless steel dipole vacuum chamber is connected to an ion pump and a sublimation pump while the NEG-coated copper dipole vacuum chamber has no additional pumps. The NEG-coated dipole chamber made of copper has been demonstrated to work well with a stable vacuum level in the region where it is installed. The coating procedure for the bent dipole chamber copper tube is slightly more complicated than the coating procedure for a straight chamber of similar size due to its curvature and lack of line-of-sight. The procedure is also described in some detail. The main motivation for the interest in NEG-coated vacuum tubes is the reduced cost of the vacuum system and also the possibility to build more slender vacuum systems, thus simplifying and optimizing the design of accelerator magnet systems.

THPP142	Vacuum Conditioning of the SOLEIL Storage Ring with Extensive Use of NEG Coating	quadrupole, storage-ring, photon, synchrotron	3696
	C. Herbeaux, N. Béchu, J.-M. Filhol SOLEIL, Gif-sur-Yvette
	The vacuum system of the SOLEIL storage ring is designed using a combination of standard pumps like Sputter Ion Pumps and Titanium Sublimation Pumps (TSP) and Non Evaporable Getter (NEG) coating. Following the ESRF results on low gap insertion device (ID) chambers, it was decided to use, in addition to the traditional pumps, NEG coating deposited by magnetron sputtering on extruded aluminium vessels. This has been applied in an extensive way to all the straight vessels of the storage ring that means quadrupole vessels and ID vessels, which represent about 56% of the circumference. The starting configuration of the SOLEIL vacuum system included all the NEG coated low gap ID chambers among which a 10.5 m long chamber. Conditioning of the vacuum system over an integrated beam dose of 500 A.h will be presented. The periodical re-activations of the TSP performed early 2007 improved significantly the conditioning rate. A comparison of the vacuum behaviour of two similar cells one with NEG coating and traditional pumping versus one with only NEG coating demonstrates the ability of the NEG coating to keep alone the pressure at low level.

THPP143	Vacuum Design of the TPS Relates to the Beam Effects	impedance, electron, ion, photon	3699
	G.-Y. Hsiung, C. K. Chan, C.-C. Chang, H. P. Hsueh, Z.-D. Tsai NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	The concept of the vacuum design for the 3 GeV Taiwan Photon Source (TPS) considers several points of view which relates to the beam effects. The vacuum design of the low outgassing rate and the effective pumping configurations to obtain the lowest average pressure in the electron storage ring is to obtain the longer beam life time and the least of the ion trapping effect and the consequent problem of beam ion instability. The inner structure of the beam ducts provides the lower impedance which reduces the problems of the collective beam instability and the heating dissipation and damage to the vacuum components. The thin wall of the beam ducts and the bellows are designed for the sextupoles that offers the function of fast feedback orbit correction of the beam. The final performance of the third generation light source with low emittance will rely on the original design of vacuum systems for the electron beam. The design philosophy of the vacuum systems for the TPS will be described.

THPP144	The Vacuum System for SSRF Storage Ring	photon, synchrotron, power-supply, storage-ring	3702
	D. K. Jiang, L. Chen, Y. L. Chen, W. Li, Y. Liu, Y. Lu, H. Zhang SINAP, Shanghai
	The vacuum system for SSRF was completed at the end of 2007 and has run for one month without any malfunction. The vacuum chamber for the storage ring made from stainless steel 316LN plate. About 180 absorbers and 80 RF bellows with a single finger structure are used for the storage ring. About 292 compound pumps (SIP+NEG) and 188 TSP are used. After the vacuum system in the straight section of a cell and all pumps in the bending section were baked, the ultimate pressure reached 2×10－8 Pa. Normally, the temperature raise on the chambers any where is less than 4℃ with current 100mA. The temperature raise of the cooling water for all absorbers is less than 3℃. The vacuum control and interlock system are on working order.

THPP145	Machine Operation Issues Related to the Vacuum System of the ESRF	undulator, cryogenics, storage-ring, beam-losses	3705
	R. Kersevan, M. Hahn, I. Parat, D. Schmied ESRF, Grenoble
	This paper deals with various operational issues related to the vacuum system of the ESRF storage ring. The impact on the vacuum pressure, beam lifetime, beam losses and other machine parameters after installation of new chambers, diagnostics, RF cavities and insertion devices, and vacuum leaks is discussed in some detail. Particular emphasis is given to the behaviour of the prototype of a 2m-long cryogenic in-vacuum undulator, a new RF cavity, and NEG-coated chambers. Lessons learned from the operation of these and other vacuum components will be extended to the proposed machine upgrade.

THPP146	High-voltage Power Supply Distribution System	ion, controls, storage-ring, monitoring	3708
	M. Kobal, D. Golob, M. Plesko, A. Podborsek Cosylab, Ljubljana T. Kusterle, M. Pelko JSI, Ljubljana
	High-voltage splitters enable connecting a larger number of ion-pumps to a single ion-pump controller. In particle accelerator facilities where relatively small pumps are used, using high-voltage splitters can significantly reduce costs and rack space. By using simple high-voltage splitters some functionality of the conrollers can be lost. The presented high-volage splitter is one of the most advanced devices on the market. It measures current going to every pump in the range 100 pA to 100 mA with an accuracy of 5%. Fully configurable tables are used to convert the measured current to the pressure at the pump. Current measurements are also used to monitor cable and ion-pump aging which results in linear increase of current with time. Hardware interlocks are used to disconnect individual pumps in case of poor vacuum to avoid pump damage. The limits can be set by the user, who can also set the number of active pumps. EPICS support was developed for the device with graphical user interfaces writen in EDM, java and WebCA. Since the presented device covers or exceeds a lot of the ion-pump controller functionality, simpler controlers can be used.

THPP147	NEG Coated Chambers at SOLEIL: Technological Issues and Experimental Results	synchrotron, controls, radiation, 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.

THPP148	Implementation of the SSRF Vacuum Control System	controls, power-supply, ion, booster	3714
	H. F. Miao, W. Li, Y. J. Liu, L. R. Shen SINAP, Shanghai
	The Shanghai Synchrotron Radiation Facility (SSRF) is a third generation light source consisting of a 150MeV linac, a full energy booster and a 3.5GeV storage ring. The vacuum control system is a standard hierarchical control system based on EPICS. Serial device servers are used to connect most of vacuum devices such as gauge controllers, pump power supplies to the control network directly and integrated with EPICS using soft IOC. Ethernet based PLC systems are adopted for the valves control, temperature monitor, etc. The soft IOCs are running on the rack servers and the VLAN is used for separate to the other systems. An enhanced distributed archive engine stores runtime data to centre database that using native XML data type with XML schema for data storage. It is a high performance system and running well for daily operation now.

THPP150	LANSCE Vacuum System Refurbishment Plan and Vacuum Alert System Improvements for Predictive Maintenance	ion, linac, power-supply, monitoring	3717
	T. Tajima, M. J. Borden, A. Canabal, J. P. Chamberlin, S. Harrison, F. R. Olivas, M. A. Oothoudt LANL, Los Alamos, New Mexico
	The Los Alamos Neutron Science Center (LANSCE) accelerator, an 800-MeV H⁺/H^- LINAC with a storage ring, has been operated over 30 years since early 1970s. A refurbishment project named LANSCE-R was approved and started in 2007. This paper describes our plan for vacuum system refurbishment as well as an update on the ongoing vacuum email alert system improvement project, which will eventually notify workers of the need for predictive maintenance of particular devices like ion pumps.

THPP151	Feasibility Study for High Performance Vacuum Chamber	photon, electron, storage-ring, positron	3720
	Y. Tanimoto KEK, Ibaraki
	For longer beam lifetime, many synchrotron light sources employ ante-chamber type of beam ducts to reduce photon- and electron-stimulated desorption gases around stored beams. Still more reduction, however, can be expected if an X-ray transparent membrane, such as Beryllium thin film, is installed between the beam chamber and the ante-chamber because X-rays from stored beams pass through the membrane while gas molecules desorbed in the ante-chamber are shut out by the membrane. Similarly, photoelectrons and secondary electrons traveling from the ante-chamber to the beam chamber are also shut out by the membrane; this function is expected to mitigate beam-photoelectron instability in positron storage rings. Feasibility study for this type of vacuum chamber has been started at PF, and the result of the first-stage experiment will be presented.