DIAMOND

Paper	Title	Other Keywords	Page
MOPCH054	Plans for the Generation of Short Radiation Pulses at the Diamond Storage Ring	radiation, storage-ring, optics, synchrotron	160
	R. Bartolini Diamond, Oxfordshire M. Borland, K.C. Harkay ANL, Argonne, Illinois
	Diamond is a third generation light source under commissioning in Oxfordshire UK. In view of the increasing interest in the production of short radiation pulses, we have investigated the possibility to operate with a low-alpha optics, the use of a third harmonic cavity for bunch shortening and the implementation of a crab cavity scheme in the Diamond storage ring. The results of the initial accelerator studies will be described, including the modification of the beam optics, non-linear beam dynamics optimisation and choice of RF parameters for the crab cavity operation. The expected performance of these schemes will be summarised.
MOPCH164	Status of the Diamond Storage Ring Radio Frequency System	controls, storage-ring, pick-up, power-supply	445
	M. Jensen, M. Maddock, S.A. Pande, S. Rains, A. F. Rankin, D. Spink, A.V. Watkins Diamond, Oxfordshire J. Alex, M. Mueller Thomson Broadcast & Multimedia AG, Turgi B. A. Aminov CRE, Wuppertal M. Pekeler ACCEL, Bergisch Gladbach
	The installation and commissioning of the Diamond Storage Ring RF system is nearing completion. Diamond will initially operate with two RF high power amplifiers and two cavities. The key components in each RF system are a 300 kW amplifier implemented through the combination of four 80 kW IOTs, a 500 MHz superconducting cavity providing up to 2 MV of accelerating voltage and an advanced analogue IQ Low Level RF (LLRF) system to control the cavity frequency, voltage and phase. We present here an update on the recent installation and early commissioning results of the RF systems.
MOPCH169	High Pressure Rinsing Water Jet Characterization	LEFT, TESLA, linear-collider, collider	460
	D. Sertore, E. Cavaliere, M. Fusetti, P. Michelato, C. Pagani, P. Pierini INFN/LASA, Segrate (MI)
	High pressure rinsing is widely used as the final wet step in the high field superconducting cavities production. The interaction of an high speed ultra pure water jet with the niobium surface depends on various parameters such as water pressure, water throughput, treatment duration, cavity rotation speed, etc. In this paper we illustrate a simple technique for the characterization of water jet parameters based on the momentum transfer between the water jet and a load cell. The jet profile and its dependence on water pressure as well as the force exerted by the jet on the surface are easily measured. Moreover a portable apparatus has been set up and the information gathered in different laboratories will be used for a quantitative comparison of the different HPR systems. These measurements allow to study the correlation of the jet parameters with the effects (surface status, oxide formation, corrosion, etc) of the water interaction with the niobium surface. Furthermore a new analysis, based on the luminescence induced on transparent dielectric samples, is used for confirmation of the water jet structure.
MOPCH196	Diamond Storage Ring Remote Alignment System	alignment, survey, storage-ring, controls	523
	I.P.S. Martin, A.I. Bell, A. Gonias, N.P. Hammond, J. Kay, D. Wilson Diamond, Oxfordshire
	The 24 cell Diamond Storage Ring is 561.6m in circumference and is mounted on 72 support girders, the largest of which are 6m long and weigh 17 Tonnes. Each girder can be remotely positioned in 5 axes using a system of motorised cams. This system has been designed to enable the future remote realignment of the Storage Ring using beam based alignment techniques. The system is described in detail including the mechanical and electrical components of the system as well as a description of the alignment algorithms employed and how these have been incorporated into the control system.
TUPCH044	Turn-by-turn Data Acquisition and Post-processing for the Diamond Booster and Storage Ring	booster, betatron, storage-ring, injection	1103
	R. Bartolini, M.G. Abbott, I.P.S. Martin, G. Rehm, J.H. Rowland Diamond, Oxfordshire
	The Diamond booster and storage ring are equipped with Libera Electron Beam Position Processors with turn-by-turn capabilities. We describe here the turn-by-turn data acquisition system and the software used for post-processing the beam data. The signals from the Libera boxes are acquired and controlled with EPICS and then transferred to the MATLAB environment via the MATLAB Channel Access. Here they are post-processed using MATLAB capabilities and dedicated software linked to MATLAB. Examples of data acquired and measurements performed during Diamond booster and storage ring commissioning are reported.
TUPCH045	First Use of Current and Charge Measurement Systems in the Commissioning of Diamond	booster, linac, storage-ring, injection	1106
	A.F.D. Morgan, M.G. Abbott, G. Rehm Diamond, Oxfordshire
	This paper will discuss the results obtained from the charge and current measurement systems installed in Diamond during the commissioning stage of operation. The charge measurements are gathered from integrating current transformers and Faraday cups, while the current is measured using a DC current transformer in each ring. The measured beam parameters will be investigated, as well as how well the devices performed against expectations.
TUPCH046	Performance of Global Diagnostics Systems during the Commissioning of Diamond	booster, storage-ring, injection, controls	1109
	G. Rehm, M.G. Abbott Diamond, Oxfordshire
	This paper summarises data acquired with beam diagnostics systems distributed globally through Diamond's Linac, transfer paths, booster and storage ring. It shows results from the electron beam position monitors using their capabilities to monitor transient events, the booster ramp as well as stored beam. The performance derived from real beam measurements is compared to measurements obtained in the lab using signal and pulse generators. Other systems of widespread use are screens and synchrotron light monitors. Their performance and control system integration based on IEEE1394 camera technology is presented. Finally, first results from the fast and slow beam loss monitoring systems are described.
TUPCH047	Diamond Optical Diagnostics: First Streak Camera Measurements	injection, electron, synchrotron, storage-ring	1112
	C.A. Thomas, G. Rehm Diamond, Oxfordshire
	We present in this paper a first set of measurements of the six-dimensional phase-space of the electron beam in the Diamond storage ring. We recall the predicted performance and compare it with our first measurements. The two pinhole cameras measure the beam size, from which we retrieve the energy spread and the emittance of the beam in both horizontal and vertical directions. We have designed a robust and simple UV-visible beamline, to measure the electron bunch profile and length with a streak camera, and to measure the beam quality using a state-of-the-art single photon counting technique.
TUPCH120	The Diamond Light Source Booster RF System	booster, controls, pick-up, synchrotron	1295
	C. Christou, V.C. Kempson Diamond, Oxfordshire K. Dunkel ACCEL, Bergisch Gladbach A. Fabris ELETTRA, Basovizza, Trieste
	The Diamond Light Source (DLS) accelerator complex can be divided into three major components; a 3 GeV 561 m circumference storage ring, a 158.4 m circumference full-energy booster synchrotron and a 100 MeV pre-injector linac. This paper describes the design and presents commissioning results of the RF system for the booster synchrotron. Booster RF commissioning took place in late 2005 and early 2006 and involved the setting-into-operation of a 60 kW IOT amplifier, supplied by Thales Broadcast and Multimedia, a 5-cell copper cavity, manufactured by Accel Instruments, and a low-level RF system designed and built by Sincrotrone Trieste SCpA.
TUPCH128	New Cutting Scheme of Magnetic Alloy Cores for J-PARC Synchrotrons	synchrotron, acceleration, KEK, beam-loading	1313
	C. Ohmori, S. Anami, E. Ezura, Y. Funahashi, K. Hara, K. Hasegawa, A. Takagi, M. Toda, K. Ueno, M. Yoshii KEK, Ibaraki Y. Morita, T. Yoshioka ICEPP, Tokyo M. Nomura, A. Schnase, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	A new cutting method using a grindstone was developed to manufacture the magnetic alloy cores. The problem of local temperature rise around the cut surfaces was solved. Long-term high-power tests have been performed for both J-PARC RCS and MR RF systems. Mechanism of local heating, new cutting scheme, and manufacturing method are presented.
TUPCH153	IOT Testing at the ERLP	ERLP, power-supply, controls, klystron	1382
	J.F. Orrett, S.R. Buckley, P.A. Corlett, A.J. Moss CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire S. Rains Diamond, Oxfordshire
	The testing of Inductive Output Tubes (IOT) at 1.3GHz is underway for use on the Energy Recovery Linac Prototype (ERLP) being constructed at Daresbury Laboratory. A 50KV high voltage power supply (HVPS) has been commissioned and characterised for use as a test RF supply. This will be used to power the ERLP RF system in both continuous and pulse modes of operation. First results are presented of the IOTs and the use of the HVPS system.
TUPCH164	Ka-band Test Facility for High-gradient Accelerator R&D	vacuum, SLAC, cathode, CLIC	1408
	M.A. LaPointe, J.L. Hirshfield, E.V. Kozyrev Yale University, Physics Department, New Haven, CT A.A. Bogdashov, A.V. Chirkov, G.G. Denisov, A.S. Fix, D.A. Lukovnikov, V.I. Malygin, Yu.V. Rodin, M.Y. Shmelyov IAP/RAS, Nizhny Novgorod S.V. Kuzikov, A.G. Litvak, O.A. Nezhevenko, M.I. Petelin, A.A. Vikharev, V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut G.V. Serdobintsev BINP SB RAS, Novosibirsk S.V. Shchelkunov Columbia University, New York
	Achievement of high acceleration gradients in room-temperature structures requires basic studies of electric and magnetic RF field limits at surfaces of conductors and dielectrics. Facilities for such studies at 11.4 GHz have been in use at KEK and SLAC; facilities for studies at 17.1 GHz are being developed at MIT and UMd; and studies at 30 GHz are being conducted at CERN using the CLIC drive beam to generate short intense RF pulses. Longer pulse studies at 34 GHz are to be carried out at a new test facility being established at the Yale Beam Physics Laboratory, built around the Yale/Omega-P 34-GHz magnicon. This high-power amplifier, together with an available ensemble of components, should enable tests to be carried at up to about 9 MW in 1 mcs wide pulses at up to four output stations or, using a power combiner, at up to about 35 MW in 1 mcs wide pulses at a single station. RF pulse compression is planned to be used to produce 100-200 MW, 100 ns pulses; or GW-level, 1 mcs wide pulses in a resonant ring. A number of experiments have been prepared to utilize multi-MW 34-GHz power for accelerator R&D, and users for future experiments are encouraged to express their interest.
TUPLS108	Realization of Thick Hybrid Type Carbon Stripper Foils with High Durability at 1800K for RCS of J-PARC	injection, vacuum, ion, linac	1753
	I. Sugai, K. Hara, H. Kawakami, M. Oyaizu, A. Takagi, Y. Takeda KEK, Ibaraki T. Hattori, K.K. Kawasaki RLNR, Tokyo Y. Irie, J. Kamiya, M. Kinsho JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	The J-PARC requires thick carbon stripper foils (250-500 ug/cm2) to strip electrons from the H-beam supplied by the linac before injection into a 3 GeV Rapid Cycling Synchrotron. The 200 MeV H- beam from the linac has a pulse length of 0.5 ms with a repetition rate of 25 Hz and an average beam current of 335 uA. By much energy deposition of these high-intensity H- and circulating bunched beams, commercially available best stripper foils (CM) will break in a very short time and even a diamond foil will rupture at around 1800K by MW class accelerators. We have realized for first time the hybrid boron doped carbon stripper foils with long life time for J-PARC. The foils of 250-500 ug/cm2 were made by a controlled DC arc-discharge method. The lifetime was tested by using 3.2 MeV Ne+ DC beam of 2.5 uA and 750 keV H- DC beam of 500 uA, in which a significant amount of energy was deposited in the foils. The maximum lifetime was extremely long, 120- and 480-times than those of diamond and CM foils. The foils were also free from any shrinkage, and showed low thickness reduction rate even at high temperature of 1800K during long time irradiation of 90h.
WEXPA02	New Developments on RF Power Sources	klystron, storage-ring, linac, ESRF	1842
	J. Jacob ESRF, Grenoble
	The classical generation of RF power with klystrons and tetrodes is evolving and changing to meet the demands of higher efficiency and simpler maintenance. Developments of IOT tubes for FEL, Energy Recovery Linacs and Storage Rings, together with solid state technology approaches and combination techniques for high power generation are opening new alternatives to the classical ones. An overview of the new concepts, designs and solutions applied to the new accelerators will be presented. Advantages and drawbacks of new versus classical technologies as well as strategies for the selection will be discussed.
	Transparencies
WEPCH074	Progress with Non-linear Beam Dynamic Studies of the Diamond Storage Ring	lattice, sextupole, injection, dynamic-aperture	2089
	R. Bartolini, I.P.S. Martin, B. Singh Diamond, Oxfordshire J.K. Jones CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The conflicting requirements of high-brightness photon beams combined with adequate beam lifetime and high injection efficiency mean careful control of the non-linear lattice is crucial to achieving optimum performance. As part of the optimisation of the Diamond storage ring, studies have been made of both the Touschek lifetime and storage ring injection process, with the help of on-momentum and off-momentum frequency maps. The effect of chromaticity on Touschek lifetime has also been investigated and several new sextupole settings were identified achieving good Touschek lifetime and injection efficiency.
WEPLS038	Design of Diamond-lined Accelerator Structure Test Cavity	collider, CLIC, linear-collider, acceleration	2457
	C. Wang, V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut J.L. Hirshfield, M.A. LaPointe Yale University, Physics Department, New Haven, CT
	For a high-gradient normal-conducting accelerator structure for a future multi-TeV linear collider, the main limitation to achievement of high acceleration gradient is RF breakdown. In an attempt to increase the gradient beyond limits that are acceptable for metallic structures, a diamond-lined structure is suggested. The published DC breakdown limit for CVD diamond is ~2 GV/m, but the limit has never been determined for RF fields. Here we present a design for a 34-GHz diamond-lined rectangular test cavity, operating in the symmetric LSM-1,1,6 mode with symmetric side input couplers. The goal is to produce as high electric fields as possible (approaching 1 GV/m) at the diamond surfaces with ~10 MW of input power supplied by the Omega-P/Yale 34-GHz magnicon for experiment test of dielectric strength.
WEPLS039	Developments on a Diamond-based Cylindrical Dielectric Accelerating Structure	impedance, electron, vacuum, simulation	2460
	A. Kanareykin, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio M.E. Conde, W. Gai, J.G. Power ANL, Argonne, Illinois P. Schoessow Tech-X, Boulder, Colorado
	Developments on a high gradient diamond-based cylindrical dielectric loaded accelerator (DLA) is presented. A diamond-loaded DLA can potentially sustain accelerating gradients far in excess of the limits experimentally observed for conventional metallic accelerating structures. The electrical and mechanical properties of diamond make it an ideal candidate material for use in dielectric accelerators: high RF breakdown level, extremely low dielectric losses and the highest available thermoconductive coefficient. We used the hot-filament Chemical Vapor Deposition (CVD) process to produce high quality 5-10 cm long cylindrical diamond layers. Our collaboration has also been developing a new method of CVD diamond surface preparation that reduces the secondary electron emission coefficient below unity. Special attention was paid to the numerical optimization of the coupling section, where the surface magnetic and electric fields were minimized relative to the accelerating gradient and within known metal surface breakdown limits.
WEPLS066	Harmonic Measurement and Adjustment of Diamond Quadrupoles	sextupole, octupole, quadrupole, alignment	2532
	C.P. Bailey, N. Marks Diamond, Oxfordshire F. Goldie, B. Leigh Tesla Engineering Limited, West-Sussex
	The 254 quadrupole magnets for Diamond, manufactured by Tesla Engineering Ltd, were measured for harmonic content to a level around 1 part in 104. In order to meet the demanding requirements on field quality, procedures were then developed to adjust the relative positions of the magnet quadrants such that the desired harmonic levels were achieved. This process was integrated into the analysis software so that the needed changes were specified. The measurements were performed on a seven-coil rotating coil rig, which also enabled the alignment of the magnet in five spatial degrees of freedom to the specified accuracy. In this report we describe the measurement and correction procedures and present a summary of the results that were obtained.
WEPLS067	Magnets for the 3 GeV Booster Synchrotron for the Diamond Light Source	dipole, quadrupole, sextupole, booster	2535
	S.P. Mhaskar, C.P. Bailey, G.M.A. Duller, V.C. Kempson, N. Marks Diamond, Oxfordshire F. Bødker, N. Hauge, L.H. Helmersen Danfysik A/S, Jyllinge
	The Diamond Booster is a full energy injector for the Diamond Storage Ring. It is designed to accelerate electrons from 100 MeV to 3 GeV at a 5 Hz repetition rate. The lattice is a missing dipole FODO lattice consisting of 22 unit cells with 36 dipoles, 44 quadrupoles, 28 sextupoles and 44 correctors, distributed around a circumference of 158.4 m. The dipole field will be ramped from 0.026 T at injection to 0.809 T at 3 GeV; the quadrupoles will have a maximum operating gradient of 15T/m. The initial design of pole tip profiles was carried at Diamond, with the magnets then manufactured by DANFYSIK A/S as part of preassembled girder units (44 in total), complete with vacuum vessels. High quality was required to meet the accelerator physics requirements of alignment, positioning accuracies and field tolerances over the required good field apertures. Materials, ramp rates and field range have been selected to obtain almost linear response during magnet ramping. This paper describes the main features of the magnetic designs and measurement results; the magnets have now been delivered and installed at Diamond.
WEPLS124	Diamond Booster Magnet Power Converters	booster, controls, dipole, quadrupole	2664
	J.A. Dobbing, C.A. Abraham, R.J. Rushton Diamond, Oxfordshire F. Cagnolati, M.P.C. Pretelli, L. Sita O.C.E.M. S.p.A., Bologna G. Facchini CERN, Geneva C. Rossi CASY, Bologna
	This paper will describe the design, factory tests, commissioning and early operation of the Diamond Booster Power Converters. The Power Converters covered are the Dipole, Quadrupole with two outputs, two bi-polar Sextupoles and 44 Steerers. The actual achieved performance will be compared with the specification and the extensive modelling that was carried out during the design phase. The design includes measures to enhance the reliability of the power converters, such as redundancy, plug-in modularity, component de-rating and component standardisation. All the Diamond power converters use the same digital controller, manufactured under licence from the Paul Scherrer Institute.
THXPA01	Overview of the Status of the Diamond Project	storage-ring, booster, vacuum, injection	2718
	R.P. Walker Diamond, Oxfordshire
	The presentation will outline the status of the Diamond project including an overview of the major areas of technical challenge including reference to the physics issues and their impact on design and performance. The majority of the talk will present the status and challenges of first commissioning, outlining the current performance and the challenges in achieving operational status.
	Transparencies
THPCH042	Numerical Estimations of Wakefields and Impedances for Diamond Collimators	impedance, simulation, storage-ring, injection	2877
	S.A. Pande, R. Bartolini, R. T. Fielder, M. Jensen Diamond, Oxfordshire
	The storage ring of the Diamond light source will use two collimators, one in horizontal and one in the vertical planes in the injection straight to protect the IDs from the injection and Touschek losses. These collimators, in the form of tapered metallic intrusions in to the vacuum chamber, will generate considerable wake fields and will contribute to the overall machine impedance. In this paper we present the results of ABCI and MAFIA numerical simulations to estimate these effects.
THPCH066	Transient Beam Loading in the DIAMOND Storage Ring	beam-loading, simulation, storage-ring, damping	2937
	S. De Santis, J.M. Byrd LBNL, Berkeley, California R. Bartolini Diamond, Oxfordshire
	Harmonic cavity systems have been installed on several 3rd generation light sources to lengthen the bunches and increase the Touschek lifetime. Apart from this beneficial effect, harmonic cavities are known to increase the transient beam loading in high-current machines, due to the presence of gaps in the fill pattern. The amplitude of this effect, which is substantially larger than that caused by the main RF system, can in turn produce considerable variations in bunch length and phase along the train, which result in a significant reduction of the lifetime increase. We have developed a tracking simulation, which we have applied to the analysis of the beam loading transients in Diamond, for the case of passive superconducting harmonic cavities. The influence of beam current, gap amplitude and harmonic cavity tuning on the final lifetime have been studied, as well as the effects of higher-order modes.
THPCH112	High-level Software for Diamond Commissioning and Operation	booster, storage-ring, controls, quadrupole	3065
	R. Bartolini, C. Christou, I.P.S. Martin, J.H. Rowland, B. Singh Diamond, Oxfordshire
	The Diamond accelerator complex is controlled with EPICS. While generic applications are provided by the EPICS toolkit, accelerator physics application for the commissioning and operation of the Diamond booster, storage ring and transfer line are mainly developed with MATLAB. The MATLAB Middle Layer tools developed at ALS and SPEAR3 have been extensively used and extended with many new applications. Experience using these tools during the commissioning of the Diamond booster, transfer lines and storage ring are reported.
THPCH113	The Diamond Light Source Control System	controls, vacuum, booster, linac	3068
	M.T. Heron, M.G. Abbott, P.H. Amos, K.A.R. Baker, Y.S. Chernousko, T.M. Cobb, C.A. Colborne, P.N. Denison, I.J. Gillingham, A. Gonias, P. Hamadyk, S.C. Lay, M.A. Leech, P.J. Leicester, M. McClory, U.K. Pedersen, N.P. Rees, A.J. Rose, J.H. Rowland, E.L. Shepherd, S.J. Singleton, I. Uzun, K. Vijayan Diamond, Oxfordshire S. Hunt PSI, Villigen P.H. Owens CCLRC/DL, Daresbury, Warrington, Cheshire
	Diamond is a new 3rd generation synchrotron light source currently being commissioned in the UK. The control system for Diamond will be a site-wide monitoring and control system for the accelerators, beamlines and conventional facilities. This paper presents the design and implementation of the Diamond control system, which is based on the EPICS control system toolkit. It will present the detailed choice of hardware and software, the solutions realised for interfacing and control of the major technical systems of Diamond, together with progress on installation and commissioning.
THPCH166	The Timing System for Diamond Light Source	booster, linac, gun, controls	3182
	Y.S. Chernousko, A. Gonias, M.T. Heron Diamond, Oxfordshire T. Korhonen PSI, Villigen E. Pietarinen, J. Pietarinen MRF, Helsinki
	The Diamond timing system is the latest generation development of the design, principles and technologies currently implemented in the Advanced Photon Source and Swiss Light Source timing systems. It provides the ability to generate reference events, distribute them over a fibre-optic network, and decode and process them at the equipment to be controlled. The timing system is closely integrated within the Diamond distributed control system, which is based on EPICS. The Diamond timing system functionality and performance, and first operational experiences in using the timing system during the commissioning of the accelerators, are presented in this paper.
THPCH167	Commissioning of the Diamond Pre-injector Linac	linac, emittance, dipole, single-bunch	3185
	C. Christou, V.C. Kempson Diamond, Oxfordshire K. Dunkel, C. Piel ACCEL, Bergisch Gladbach
	Commissioning of the linac for the Diamond Light Source (DLS) was completed in October 2005. The linac was supplied by Accel Instruments as a complete system, with DLS providing beam diagnostics, beam analysis software, control system hardware and standard vacuum components. Much of the beam analysis was carried out using the first part of the Linac to Booster transfer line (LTB), which was designed and built by DLS. Operation of the linac and LTB at 100 MeV in long-pulse and short-pulse modes of operation was demonstrated, and all operational parameters were measured to be within specification.
THPCH168	RF Distribution System of the Diamond Master Oscillator	synchrotron, linac, storage-ring, booster	3188
	A.V. Watkins, M. Jensen, M. Maddock, S.A. Pande, S. Rains, D. Spink Diamond, Oxfordshire
	A modular RF distribution system has been designed and built at Diamond Light Source to distribute the master oscillator (MO) signal. The system will deliver a low noise, phase stable 500 MHz signal to multiple points of use around the synchrotron facility. Providing phase stability and preserving noise performance over the distances required (up to 300m) have been the main design challenges. A modular approach provides future flexibility, and this paper describes each component, outlining design choices, components used, construction details and test results.
THPCH174	Multipactor Electron Gun with CVD Diamond Cathodes	electron, cathode, gun, ion	3203
	J.Y. Zhai, C.-X. Tang, S. Zheng TUB, Beijing
	A Multipactor Electron Gun (MEG) is developed for the high power microwave generation in the Accelerator Lab of Tsinghua University. This paper presents the recent experimental results of the S-band MEG using hydrogen-terminated and CsI-terminated CVD diamond cathodes. The gun design, cathode preparation and high power experiment are described. An electron beam with 5 μs macro-pulse, 10 Hz repetition rate, greater than 900 mA beam current was obtained.calculation and computer simulation. The properties of the secondary electron emission cathodes are also discussed.
THPCH193	Comparison between H-ion and Heat Cleaning of Cu-metal Cathodes	cathode, gun, GTF, LCLS	3245
	D. Dowell, F. King, R.E. Kirby, J.F. Schmerge SLAC, Menlo Park, California
	Understanding the quantum efficiency (qe) of a metal photocathode in an s-band RF gun is important to limit the drive laser energy requirement and provide the best quality electron beam. Systematic measurements of the qe vs. wavelength for varying surface contamination have been performed on copper samples using x-ray photoelectron spectroscopy (XPS). The sample is first cleaned to the theoretical limit of qe using a 1 keV hydrogen ion beam. The H-ion beam cleans an area approximately 1cm in diameter and has no effect on the surface roughness while removing essentially all contaminants and lowering the work function to 4.3eV. The sample is then exposed to atmospheric contaminants (nitrogen and oxygen) and measured again with XPS to determine the degree of contamination and the effect on the qe. The goal is to determine the best procedure for transferring and installing cathodes in an s-band gun. These results and comparison with a heat cleaned cathode are presented.
THPLS025	Diamond Light Source Vacuum Systems Commissioning Status	vacuum, storage-ring, controls, photon	3332
	M.P. Cox, B. Boussier, S. Bryan, B.F. Macdonald, H.S. Shiers Diamond, Oxfordshire
	Diamond Light Source is a new 3 GeV light source currently being commissioned in the UK. The main vacuum systems are a 561.6 m circumference electron storage ring and a 158.4 m circumference booster ring. The storage ring target operating pressure is 1·10-9 mbar with 300 mA of stored beam after 100 A.h of beam conditioning. The booster ring target operating pressure is up to an order of a magnitude higher. Pumping is provided by discrete noble diode ion pumps, supplemented by titanium sublimation pumps and NEG cartridge pumps. Vacuum vessel construction is mainly from 316LN stainless steel. There is no in situ bakeout except for the 24 storage ring straights and the front ends. An ex situ bakeout process is used for the storage ring arcs followed by installation under vacuum. This paper reports results and experience from the construction and commissioning of the diamond vacuum systems.
THPLS027	Vibration Measurement at Diamond and the Storage Ring Response	storage-ring, ground-motion, synchrotron, site	3338
	H.C. Huang, J. Kay Diamond, Oxfordshire
	Controlling and minimising the sources and transmission of vibration in Synchrotron Light Sources is an important factor in achieving the stability needed to generate the very brightest beams. This paper describes the equipment that has been used at Diamond to measure vibration and reports the results of measurements taken on the accelerator floor and on the girder structures carrying the Storage Ring. A description is given of the intensively piled foundations and a comparison is made between the measured response and the modelled response. The contribution to vibration from water and ventilation services is also discussed.
THPLS029	Commissioning of the Booster Synchrotron for the Diamond Light Source	booster, injection, extraction, dipole	3344
	V.C. Kempson, R. Bartolini, C. Christou, J.A. Dobbing, G.M.A. Duller, M.T. Heron, I.P.S. Martin, G. Rehm, J.H. Rowland, B. Singh Diamond, Oxfordshire
	The Diamond booster is a 158 m circumference, 5 Hz synchrotron which accelerates the 100 MeV electron beam from a linac to 3 GeV for full-energy injection into the Diamond storage ring. The booster has been commissioned in the first few months of 2006, following successful initial 100 MeV trials at the very end of 2005. The injection and ramping process, orbit correction and essential beam physics measurements are discussed as are extraction and beam transport to the storage ring.
THPLS030	Beam Optic Measurements for the Booster Synchrotron of the Diamond Light Source	booster, injection, lattice, quadrupole	3347
	B. Singh, R. Bartolini, C. Christou, V.C. Kempson, I.P.S. Martin Diamond, Oxfordshire J.K. Jones CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The booster synchrotron of the Diamond Light Source is a full energy injector ramping from 100 MeV to 3 GeV with a repetition rate of 5 Hz. As part of the booster commissioning, beam optic measurements were performed to characterize the booster performance. Through the use of the beam position monitors, orbit corrections, tune and chromaticity measurements were performed at injection energy and during the ramp. A first comparison with the booster model is also discussed.
THPLS128	Overview of Diamond IDs for Phase 1	wiggler, insertion, insertion-device, factory	3586
	E.C. Longhi, A.I. Baldwin, S.P. Mhaskar, J.C. Schouten, C.W. Thompson Diamond, Oxfordshire
	Diamond Light Source is a 3GeV synchrotron currently under construction in the UK, which will be operational in early 2007. It is a third generation light source comprising 22 usable straight sections for insertion devices. Phase 1 of beamline construction will include eight Insertion Devices: five PPM in-vacuum undulators, two APPL·10-2 devices to be installed in the same straight, and one 3.5T superconducting wiggler. This paper describes the current status of construction and magnetic measurements for each of the Phase 1 devices.