EPAC 2006 - Classification:06 Beam Instrumentation and Feedback/T03 Beam Diagnostics and Instrumentation

06 Beam Instrumentation and Feedback

T03 Beam Diagnostics and Instrumentation

Paper	Title	Page
TUYPA01	Femtosecond Bunch Length Measurements	915
	S.P. Jamison CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire G. Berden FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland A. MacLeod UAD, Dundee B. Steffen DESY, Hamburg
	The measurement of ultrashort longitudinal bunch profiles is of growing importance to accelerator development and operation. With requirements of ~10fs time resolution, and a desire for non-destructive and real time diagnostics, the challenges for diagnostic development are significant. Alongside more established transverse deflecting cavity and CTR measurement techniques, new approaches arriving from the field of ultrafast lasers offer significant potential; Ultrafast electro-optic detection has now been demonstrated on several accelerators, and in many distinct forms, although challenges remain in getting to the desired time resolution. Proposed schemes combining ultrafast laser diagnostics with FEL interactions, such as the "optical replica" scheme also have considerable potential. Here, an overview of the current status of femtosecond scale longitudinal profile diagnostics will be given, together with an outlook to the future expectations.
	Transparencies
TUYPA02	High Precision SC Cavity Alignment Diagnostics with HOM Measurements	920
	J.C. Frisch, L. Hendrickson, J. May, D.J. McCormick, S. Molloy, M.C. Ross, T.J. Smith SLAC, Menlo Park, California N. Baboi, O. Hensler, L.M. Petrosyan DESY, Hamburg N.E. Eddy, S. Nagaitsev Fermilab, Batavia, Illinois O. Napoly, R. Paparella, C. Simon CEA, Gif-sur-Yvette
	Experiments at the TTF at DESY have demonstrated that the Higher Order Modes induced in Superconducting Cavities can be used to provide a variety of beam and cavity diagnostics. The centers of the cavities can be determined from the beam orbit which produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used as a high resolution beam position monitor, and the phase of the monopole modes to measure the beam phase relative to the accelerator RF. Beam orbit feedback which minimizes the dipole HOM power in a set of structures has been demonstrated. For most SC accelerators, the existing HOM couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional BPM.
	Transparencies
TUYPA03	Developments in Beam Instrumentation and New Feedback Systems for the ILC	925
	H. Hayano KEK, Ibaraki
	This presentation will review the challenging beam properties that need to be measured and controlled and new diagnostic developments that address these challenges for ILC beam instrumentation.
	Transparencies
TUPCH003	Diagnostics and Timing at the Australian Synchrotron	995
	M.J. Spencer, S. Banks, M.J. Boland, M. Clift, R.T. Dowd, R. Farnsworth, S. Hunt, G. LeBlanc, M. Mallis, B. Mountford, Y.E. Tan, A. Walsh, K. Zingre ASP, Clayton, Victoria
	The 3GeV Australian Synchrotron will begin operation in March 2007. This paper outlines the storage ring diagnostics systems and the injection timing system. The diagnostics system includes an optical beamline with streak camera, an x-ray beamline with pinhole array, a diagnostic straight with fast feedback kicker, stripline, direct current current transformer, and a four-fingered scraper. Over the 14 sectors there are 98 beam position monitors and 14 movable beam loss monitors. The timing system is based on a static injection system with the storage ring bucket to be filled targeted by delaying the firing of the electron gun.
TUPCH004	Commissioning of the LNLS X-ray BPMs	998
	S.R. Marques, P.F. Tavares LNLS, Campinas
	We present experimental results of the commissioning of staggered-pair blade X-Ray beam position monitor (XBPM) recently developed and installed at the diagnostic beamline of the UVX electron storage ring at the Brazilian Synchrotron Light Laboratory (LNLS). The results obtained with a prototype XBPM indicate that the short-term and long-term data are both in agreement with the data from a commercially acquired XBPM installed at the same beamline, as well as with the data of the electron storage ring RF BPMs. In this paper we present the commissioning results of the LNLS XBPM.
TUPCH006	A Wideband Intercepting Probe for the TRIUMF Cyclotron	1001
	V.A. Verzilov, D. Cameron, D.T. Gray, S. Kellogg, M. Minato, W.R. Rawnsley TRIUMF, Vancouver
	An intercepting probe for the TRIUMF cyclotron capable of measuring the phase and time structure of the circulating beam was designed, manufactured, installed into the tank and tested. A model of the probe head in the form of a 50 Ohm parallel plate transmission line was developed and simulated to operate up to 2 GHz. Thermal simulations show that the probe can withstand at least 500 nA of average current for the 500 MeV beam. In laboratory tests the probe demonstrated a bandwidth in excess of 1 GHz. The probe was mounted on a 3 m long drive and is capable of travelling over 0.5 m at an angle of 27 degree w.r.t. the cyclotron radius. The signals extracted from the probe are processed by a pair of diplexers, where low frequency and high frequency components are separated. The low frequency signal is directed to our standard electronics for processing and provides both dc current and a time of flight signal with a rise time of about 100 ns. At the high frequency output a signal-to-noise ratio of about 4 at 250 nA average current and 0.1 % duty cycle was measured in the presence of rf background from the cyclotron resonators. A bunch time structure as short as 1 ns was resolved.
TUPCH007	High Resolution BPM for the Linear Colliders	1004
	C. Simon, S. Chel, M. Luong, O. Napoly, J. Novo, D. Roudier CEA, Gif-sur-Yvette N. Rouvière IPN, Orsay
	The beam-based alignment and feedback systems which are essential for the operation of the future colliders use some high resolution Beam Position Monitors (BPM). In the framework of CARE/SRF, the task of CEA/DSM/DAPNIA (Saclay) is the design, the fabrication and the beam test of a BPM in collaboration with DESY. This system is composed of a RF re-entrant cavity with a beam pipe radius of 78mm and an analog electronics having several signal processing steps to reject the monopole mode. Thanks to its high position resolution (better than 1μm) and its high time-resolution (around 10ns), it is a candidate for the X-FEL at DESY and the ILC. Indeed the chosen coupling allows the bunch to bunch measurement and the separation between the monopole and dipole modes. Moreover, this BPM is designed to be used in a clean environment, at the cryogenic and room temperatures.
TUPCH008	Behavior of the BPM System During the First Weeks of SOLEIL Commissioning	1007
	J.-C. Denard, L. Cassinari, N. Hubert, N.L. Leclercq, D. Pedeau SOLEIL, Gif-sur-Yvette
	SOLEIL, a new synchrotron light source built near Paris in France, is pioneering a new high resolution electron Beam Position Monitor (BPM) system to achieve stability of the beams at the micron level, as required for the beamlines. The same BPM system allows also measurement of the beam position in turn-by-turn mode for various machine physics studies. The system combines the high stability characteristic of multiplexed input channels and the flexibility of a digital system. Instrumentation Technologies developed the Libera module upon SOLEIL proposals and requirements. The performances of the system evaluated after the Booster and the storage ring commissioning will be presented.
TUPCH009	Beam Measurements and Manipulation of the Electron Beam in the BESSY-II Transferline for Topping Up Studies	1010
	T. Kamps, P. Kuske, D. Lipka BESSY GmbH, Berlin
	The BESSY-II storage ring based synchrotron radiation source will be upgraded to allow for continuous topping up operation. In order to achieve a high injection efficiency between the booster synchrotron and the storage ring, the transferline will be equipped with novel beam size monitors and collimators. This paper describes the collimator design and first beam measurements of the transverse emittance. The transverse emittance is measured using the quadrupole scan technique. The data taking and the analysis procedure is given together with results and comparision with simulations.
TUPCH010	Profile Measurement by Beam Induced Fluorescence for 60 MeV/u to 750 MeV/u Heavy Ion Beams	1013
	P. Forck, C. Andre, F. Becker, H. Iwase GSI, Darmstadt D. Hoffmann TU Darmstadt, Darmstadt
	At the planned heavy ion facility FAIR very intense beams of heavy ions will be transported between various synchrotrons and focused on targets for secondary ion productions. For the transverse profile determination only non-destructive methods are suited due to the large deposed beam power. We investigated experimentally the Beam Induced Fluorescence (BIF) method. Due to the atomic collision by the beam ions the residual gas N2 is excited to fluorescence levels. Single photon detection is performed by a double MCP image intensifier coupled to a digital CCD camera. Extensive experimental studies (with the today available lower ion currents) were performed to determine the photon yield and the background contribution for different ion species and beam energies. The measured profiles show a good correspondence to other methods as long as the vacuum pressure by a regulated N2 inlet is below 10-1 mbar. Based on the experimental results, the layout for a BIF profile determination will be discussed.
TUPCH011	Innovative Beam Diagnostics for the Challenging FAIR Project	1016
	P. Forck, A. Peters GSI, Darmstadt
	The planned FAIR facility consists of two heavy ion synchrotrons and four large storage rings. The super-conducting synchrotrons are build for high current operation and secondary ion production. A large variety of low current secondary beams is stored and cooled in the four storage rings. A complex operation scheme with multiple use of transport lines is foreseen. This demands an exceptional high dynamic range for the beam instrumentation. Due to the enormous beam power, non-destructive methods are mandatory for high currents. For the low current secondary beams, non-destructive diagnostics are also preferred due to the low repetition rate. Precise measurements of all beam parameters and automatic steering or feedback capabilities are required due to the necessary exploitation of the full ring acceptances. Moreover, online beam-corrections with short response times are mandatory for the fast ramping super-conducting magnets. Due to the ultra-high vacuum condition and the demanding measurement accuracy, novel technical solution are foreseen. An overview of the challenges and projected innovative solutions for various diagnostic installations will be given.
TUPCH012	Digital Techniques in BPM Measurements at GSI-ISI	1019
	A.A. Galatis, P. Kowina, K. Lang, A. Peters GSI, Darmstadt
	In this paper we describe new approaches for BPM measurements in hadron accelerators, which have strongly varying beam parameters such as intensity, accelerating frequency and bunch length. Following signal dynamic adjustment, direct digitalization and treatment of digitized data, we should reach a BPM resolution of 0.1mm. Interchangeability of this method between accelerators should be provided, which results in autonomous data treatment algorithms, free of external status and timing signalling. This should ensure the usability of the system in other bunched accelerator rings. Different operation modes are intended for allowing online storage of beam position data over full acceleration cycles as well as storage of beam waveforms in regions of acceleration that are of special interest e.g. transition, kicking, bunch gymnastics. First results of realised hardware/software combinations will be introduced and discussed.
TUPCH013	Numerical Calculations of Position Sensitivity for Linear-cut Beam Position Monitors	1022
	P. Kowina, A.A. Galatis, W. Kaufmann, J. Schoelles GSI, Darmstadt
	In this contribution the results of simulations performed for different geometries of linear-cut Beam Position Monitors (BPMs) are compared for two design types: i)based on metal electrodes and ii)using a metal coated ceramics. The advantage of the ceramic solution is a compact construction allowing easy positioning. Contrary, the construction based on the metal electrodes benefits from its simplicity. The main goals in optimization are the sensitivity and linearity of the position determination. High position sensitivity can be achieved by the reduction of the plate-to-plate cross talks caused by coupling capacities. For instance, the insertion of an additional guard ring into the gap between the active plates leads to an increase of the sensitivity by about 30%. This insertion is necessary in case of ceramic solution: The large ceramics permeability enlarges the coupling capacity by about a factor of four. The careful geometrical arrangement allows to avoid resonances in the interesting frequency range i.e. from 0.2 to 200MHz. The displayed simulations are performed using CST Microwave Studio. The investigated BPMs will be used in the FAIR facility presently under design at GSI.
TUPCH014	Machine Protection by Active Current-transmission Control at GSI-UNILAC	1025
	H. Reeg, J. Glatz, N. Schneider GSI, Darmstadt H. Walter Ing.-Buero H. Walter, Saulheim
	Toroidal beam current transformers (BCT) are installed at dedicated locations along the UNILAC accelerator. They provide an output signal with a fixed transimpedance. Dedicated signal pairs from consecutive transformers drive differential integrator stations. If preset protection levels are exceeded due to beam charge loss during the macro-pulse, fast interlock signals are generated. The actual beam pulse is instantaneously truncated by a fast beam chopper, avoiding any thermal damage or radio-activation of machine components. A new BCT macro-pulse selector/display is presently under construction, which will provide time structure observation of multiple UNILAC macro-pulses, as well as long-term data logging. The hardware is set up with PXI components from National Instruments, running a multi-client/server controller software under LabViewRT�. Offline-analysis of the accumulated BCT data is expected to improve the protection system's operation and reliability. An overview of the system layouts, technical details, and relevant operational results will be presented.
TUPCH015	Integrated Beam Diagnostics Systems for HICAT and CNAO	1028
	A. Reiter, A. Peters, M. Schwickert GSI, Darmstadt
	An integrated system for beam diagnostics was produced at GSI for the heavy-ion cancer treatment facility HICAT of the Heidelberg university clinics. A set of 92 manifold beam diagnostic devices allows automated measurements of the main beam parameters such as beam current, profile or energy. The beam diagnostic subsystem is completely integrated in the overall accelerator control system and its timing scheme. This paper reports on the underlying design patterns for the abstraction of the beam diagnostic devices towards the control system. Event-counting devices, i.e. scintillating counters and ionization chambers, are presented as examples of the diagnostic devices in the synchrotron and high-energy beam transport section of HICAT. Additionally, it is shown that the well-defined building blocks of the beam instrumentation made it possible to prepare almost identical devices including the manual control software, to be used in the CNAO facility (Centro Nazionale di Adroterapia Oncologica) presently under construction in Pavia, Italy.
TUPCH016	Numerical Simulation of Synchrotron Radiation for Bunch Diagnostics	1031
	A. Paech, W. Ackermann, T. Weiland TEMF, Darmstadt O. Grimm DESY, Hamburg
	For the operation of the VUV-FEL at DESY, Hamburg, the longitudinal charge distribution of the electron bunches that drive the free electron laser is of high importance. One novel method to measure the bunch shape is to analyze the coherent far-infrared synchrotron radiation generated at the last dipole magnet of the first bunch compressor. For the correct interpretation of the results it is mandatory to know how various parameters, like the bunch shape and path, the vacuum chamber walls, the optical beamline, etc., influence the observed spectrum. The aim of this work is to calculate the generation of synchrotron radiation inside the bunch compressor with the emphasis of including the effects of the vertical and horizontal vacuum chamber walls in the vicinity of the last dipole magnet. Challenging problems for the numerical simulations are the very short wavelength and the broad frequency range of interest. As a first step, it is shown how the radiation leaving the vacuum chamber, that is generated by a single point charge, can be calculated with the help of the uniform theory of diffraction (UTD).
TUPCH018	Fast Beam Dynamics Investigation Based on an ADC Filling Pattern Measurement	1034
	J. Kettler, P. Hartmann, R.G. Heine, T. Weis DELTA, Dortmund
	A diagnostic tool to determine the longitudinal particle filling pattern has been installed at the 1.5 GeV electron storage ring DELTA. The instrument is PC-based using an ADC-conversion at a sampling rate of 2 GS/s and a nominal bandwidth of 1 GHz which is applied to the sumsignal of a single storage ring beam position monitor. By sampling over successive turns the resolution is enhanced by one order of magnitude allowing an easy access to the longitudinal particle distribution inside the ring. The data obtained turn-by-turn over hundreds of revolutions can be further analysed by FFT-techniques allowing a very fast detection (~ 1 s) of longitudinal coupled bunch mode (CBM) instabilities from the phase modulated spectrum. The application of the FFT to the amplitude modulated particle distribution moreover allows a "post mortem"-investigation of CBM induced beam loss. The paper will present the layout of the diagnostic system and will report on filling pattern measurements as well as on investigations of longitudinal CBM-instabilities.
TUPCH019	Laser-based Beam Diagnostic for the Front End Test Stand (FETS) at RAL	1037
	C. Gabor IAP, Frankfurt-am-Main D.A. Lee Imperial College of Science and Technology, Department of Physics, London A.P. Letchford CCLRC/RAL/ISIS, Chilton, Didcot, Oxon J.K. Pozimski CCLRC/RAL, Chilton, Didcot, Oxon
	High power proton accelerators (HPPA) are required for several future projects like spallation sources or a neutrino factory. Compared with existing machines the beam power therefore has to be increased by a factor of 30. The Front end test stand at RAL is being built to demonstrate that a chopped Hminus beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality, as required for all proposed Proton drivers, can be built. For the test stand a comprehensive set of beam diagnostics is also required. Due to the high beam energy and power non destructive diagnostic methods are favorable. Hminus beams offer the possibility to use intense laser light to detach the additional electron and use the produced particles for beam diagnostics. The principle is appropriate to determine the transversal beam density distribution as well as the transversal and longitudinal beam emittance in front and behind the RFQ. A detailed layout of the beam diagnostics including a discussion of the predicted spatial and temporal resolution and the dynamic range of the proposed devices will be presented.
TUPCH021	Principles of longitudinal beam diagnostics with coherent radiation	1040
	O. Grimm DESY, Hamburg
	The Kramers-Kronig dispersion relation connects the real and imaginary part of a response function under very general assumptions. It is used in the context of accelerator physics for longitudinal bunch diagnostics as a phase retrieval technique: the modulus of the complex form factor (the Fourier transform of the charge distribution) is accessible experimentally, and the missing phase then (partially) reconstructed to allow an inversion of the Fourier transform. Contrary to real and imaginary part, the connection between modulus and phase is not unique anymore due to the possibility of zeros of the form factor in the complex frequency plane that cannot be measured. This paper gives a mathematically explicit, step-by-step derivation of the phase reconstruction technique for bunch diagnostics, and it explains the problem of zeros and their practical effect with some examples. The intention is not utmost mathematical rigour, but a clear, accessible explanation of all steps involved.
TUPCH022	Large Horizontal Aperture BPM for use in Dispersive Sections of Magnetic Chicanes	1043
	K.E. Hacker, H. Schlarb DESY, Hamburg F. Loehl Uni HH, Hamburg
	A beam position monitor with a large horizontal aperture for use in dispersive sections of FLASH magnetic chicanes will be installed in October 2006. It has a horizontal range of 13 cm and a resolution requirement of better than 10 microns. A stripline design mounted perpendicularly to the the electron beam direction is used to provide broadband electrical pulses traveling in opposite directions, the phases of which give a measure of the beam position. The phase measurement will be accomplished through an optical method developed for a beam arrival time monitor. Results from simulation and recent beam arrival-time measurements will be used to justify expectations for the BPM performance.
TUPCH023	Direct Observation of Beam-beam Induced Dynamical Beta Beating at HERA	1046
	G. Kube, F.J. Willeke DESY, Hamburg
	The Hadron Electron Ring Anlage (HERA) at DESY provides collisions between a 920 GeV proton beam and a 27.5 GeV electron beam in two interaction regions. The strong beam-beam force, which mainly affects the electrons, induces a tune shift together with a dynamical beta beat. The latter leads to a modification of the transverse beam profile, which can be observed in different profile monitors in HERA. The time-like evolution of the electron beam shape during luminosity tuning and before and after dump of the proton beam, averaged over all bunches, could be studied by means of a synchrotron radiation profile monitor. Measurements with a wire scanner allowed to see the beam-beam force's influence on each individual bunch at the expense of resolution. The observations could be explained qualitatively in the frame of linear incoherent beam-beam interaction.
TUPCH024	Comparative Study of Bunch Length and Arrival Time Measurements at FLASH	1049
	H. Schlarb, A. Azima, S. Düsterer, M. Huening, E.-A. Knabbe, M. Roehrs, R. Rybnikov, B. Schmidt, B. Steffen DESY, Hamburg M.C. Ross SLAC, Menlo Park, California P. Schmüser, A. Winter Uni HH, Hamburg
	Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At the VUV-FEL, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure. The method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. Therefore, it is augmented by two non-disruptive electro-optical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into a spatial dimension of laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
TUPCH025	Precision RF Gun Phase Monitor System for the VUV-FEL	1052
	H. Schlarb, N. Heidbrook, H. Kapitza, F. Ludwig, N. Nagad DESY, Hamburg
	For RF photo-injectors, the properties of the high brightness beam critically depend on the synchronization between the RF gun acceleration phase and the photo-cathode laser. At the VUV-FEL, the phase stability is determined by operating the RF gun close to zero-crossing RF phase. This allows the conversion of phase variations into charge variations which then is readout by a precision charge measurement system based on toroids. In this paper, we discuss the limitation of this method. Resolution reduction of the charge measurement system due to electro-magnetic-interference is discussed in detail.
TUPCH026	Single Shot Longitudinal Bunch Profile Measurements at FLASH using Electro-optic Techniques	1055
	B. Steffen, E.-A. Knabbe, B. Schmidt DESY, Hamburg G. Berden, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison, A. MacLeod UAD, Dundee P. Schmüser Uni HH, Hamburg
	For the high-gain operation of a SASE FEL, extremly short electron bunches are essential to generate sufficiently high peak currents. At the superconducting linac of the VUV-FEL at DESY, we have installed an electro-optic experiment with temporal decoding and spectral decoding to probe the time structure of the electric field of single sub 200fs e-bunches. In this technique, the field-induced birefringence in an electro-optic crystal is encoded on a chirped ps laser pulse. The longitudinal electric field profile of the electron bunch is then obtained from the encoded optical pulse by a single-shot cross correlation with a 30 fs laser pulse using a second-harmonic crystal (temporal decoding) or by a single-shot measurement of its spectrum (spectral decoding). In the temporal decoding measurements an electro-optic signal of 230fs FWHM was observed, and is limited by the material properties of the particular electro-optic crystal used. Bunch profile and time jitter measurements were obtained simultaneously with VUV SASE operation.
TUPCH027	Time Resolved Single-shot Measurements of Transition Radiation at the THz Beamline of FLASH using Electro-optic Spectral Decoding	1058
	B. Steffen, E.-A. Knabbe, B. Schmidt DESY, Hamburg G. Berden, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison, A. MacLeod UAD, Dundee P. Schmüser Uni HH, Hamburg
	Single-shot electro-optic detection was used to measure the temporal profile of coherent transition radiation (CTR) pulses at the VUV-FEL at DESY. The CTR was generated from single bunches kicked to an off-axis screen, with the radiation transported through a 20m long transfer line imaging the CTR from a radiation screen to an experimental station outside the accelerator tunnel. Bipolar pulses with a FWHM less than 1ps have been measured and are consistent with simulations of the propagation of radiation through the transfer line.
TUPCH028	Layout of the Optical Synchronization System for FLASH	1061
	A. Winter, P. Schmüser, A. Winter Uni HH, Hamburg F. Loehl, F. Ludwig, H. Schlarb, B. Schmidt DESY, Hamburg
	The present RF synchronization system of the VUV-FEL can typically stabilize the arrival time of the electron bunches at the undulator to about 200 fs on a timescale of minutes and to several picoseconds on a timescale of hours. To improve the machine stability and to ensure optimal performance for the VUV-FEL user facility, a new ultra-precise timing system is mandatory. The optical synchronization system under construction will satisfy three goals: Firstly, it provides a local oscillator frequency with the same stability as the existing low-level RF regulation, secondly, it can synchronize the experimental lasers of the FEL users with a precision in the order of 30 fs, thirdly, it provides an ultra-stable reference for beam arrival time measurements and enables a feedback on the electron beam to compensate residual drifts and timing jitter. The optical synchronization system is based on an optical pulse train from a mode-locked laser with a highly stabilized repetition rate. This paper describes the proposed layout of the optical synchronization system, the integration into the machine layout and the diagnostic experiments to monitor the performance of the system.
TUPCH029	High-precision Laser Master Oscillators for Optical Timing Distribution Systems in Future Light Sources	1064
	A. Winter, P. Schmüser, A. Winter Uni HH, Hamburg J. Chen, F.X. Kaertner MIT, Cambridge, Massachusetts F.O. Ilday Bilkent University, Bilkent, Ankara F. Ludwig, H. Schlarb DESY, Hamburg
	X-ray pulses with a pulse duration in the 10 fs regime or even less are needed for numerous experiments planned at next generation free electron lasers. A synchronization of probe laser pulses to the x-ray pulses with a stability on the order of the pulse width is highly desirable for these experiments. This requirement can be fulfilled by distributing an ultra-stable timing signal to various subsystems of the machine and to the experimental area to provide synchronization at the fs level over distances of several kilometers. Mode-locked fiber lasers serve as laser master oscillators (LMO), generating the frequencies required in the machine. The pulse train is distributed through length-stabilized fiber links. This paper focuses on the LMO, devoting special attention to the phase noise properties of the frequencies to be generated, its reliability to operate in an accelerator environment, and the residual timing jitter and drifts of the RF feedback for the fiber links. A prototype experimental system has been constructed and tested in an accelerator environment and its performance characteristics will be evaluated.
TUPCH030	A Beam Diagnostics System for the Heidelberg Cryogenic Storage Ring CSR	1067
	T. Sieber, H. Fadil, M. Grieser, A. Wolf, R. von Hahn MPI-K, Heidelberg
	The storage of rotationally non-excited molecules and highly charged ions requires lowest temperatures and vacuum pressures. At the MPI-K Heidelberg a cryogenic storage ring (CSR) for atomic and molecular physics experiments is under development. The CSR shall allow operation at temperatures of 2 K and pressures down to 1·10^-15 mbar. The ring consists of electrostatic elements and has a circumference of ~35 m. It is housed inside a large cryostat, cooled by a (20W @ 2K) Helium refrigerator. To reach low UHV pressures already at room temperature the whole machine has to be bakeable up to 300°C. These boundary conditions, together with the low charge states, low velocities and low intensities (1nA-1muA) of the ions, put strong demands on the beam diagnostics system. Some beam parameters like profile, position and intensity cannot be measured with “standard” beam diagnostics technology. Here new or further developments are required. The paper gives a general view of the beam diagnostics concept for the CSR and shows in more detail possible solutions for measurement of beam position and beam profile.
TUPCH031	A New SQUID-based Measurement Tool for Characterization of Superconducting RF Cavities	1070
	K. Knaack, K. Wittenburg DESY, Hamburg R. Neubert, S. Nietzsche, W. Vodel FSU Jena, Jena A. Peters GSI, Darmstadt
	In this contribution a LTS-SQUID based measurement tool for characterization of superconducting RF cavities for the upcoming X-FEL project at DESY will be presented. The device makes use of the Cryogenic Current Comparator (CCC) principle and measures the so-called dark current, generated e.g. by superconducting cavities at high voltage gradients. To achieve the maximum possible energy the gradients should be pushed near to the physical limit of 50 MV/m. The measurement of the undesired field emission of electrons (the so-called dark current) in correlation with the gradient will give a proper value to characterize the performance of the RF cavities. The CCC mainly consists of a high performance LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted dark current of the RF cavities. Therefore, a special designed toroidal niobium pick-up coil for the passing electron beam is superconducting connected across the input coil of the SQUID. The noise limited sensitivity of the CCC as well as new experimental results with the whole measurement device assembled in a special wide-necked LHe cryostat will be presented.
TUPCH032	Precise Measurements of the Vertical Beam Size in the ANKA Storage Ring with an In-air X-ray Detector	1073
	A.-S. Müller, I. Birkel, E. Huttel, P. Wesolowski FZK, Karlsruhe K.B. Scheidt ESRF, Grenoble
	A major part of the X-rays generated in the ANKA dipole magnets is unused by the experimental beamlines and is, on a number of dipoles, absorbed in a conical shaped Copper absorber. The 8 mm thickness that it presents lets a tiny fraction of the hard X-rays above 70KeV enter the free air space behind it. The transmitted power of only a few uW/mrad hor. is sufficient to be detected, with sub-second measurement time, by a novel In-Air X-ray detector. This extremely compact and low-cost device is situated just behind the absorber. The design, developed and in use at the ESRF, is based on a Cadmium Tungstenate (CdWO4) scintillator converting X-rays into visible light that is collected and focused onto a commercial CCD camera. Since the small vertical divergence of the high energy photons and the distance of the detector from the source point are known, it is possible to derive the vertical electron beam size with a high intrinsic precision. This paper presents results of beam size measurements as a function of various ANKA machine parameters, that illustrates the great diagnostic potential of this type of detector for a 2.5GeV medium energy light source like ANKA.
TUPCH033	Automated Beam Optimisation and Diagnostics at MAMI	1076
	M. Dehn, H. Euteneuer, F.F. Fichtner, A. Jankowiak, K.-H. Kaiser, W.K. Klag, H.J. Kreidel, S.S. Schumann, G.S. Stephan IKP, Mainz
	At the Institut fur Kernphysik (IKPH) of Mainz University the fourth stage of the Mainz Microtron (MAMI), a 855MeV to 1500MeV Harmonic Double Sided Microtron (HDSM), is now on the verge of first operation. To provide an automated beam optimisation, low-Q-TM010 and TM110 resonators at each linac of the three cascaded RTMs and the two linacs of the new HDSM are used. These monitors deliver position, phase and intensity signals of each recirculation turn when modulating the beam intensity with 12ns-pulses (diagnostic pulses, max. rep. rate 10kHz). For operating the HDSM an extended system for displaying and digitising these signals was developed. High-bandwidth ADCs allow very comfortable to analyse, calibrate and automatically optimise the beam positions and phases during operation. The system is also used to adjust the transversal and longitudinal focussing according to the design parameters. Synchrotron radiation monitors, providing beam sizes and positions out of the bending magnets for each turn and on the entrance and exit of the linac axis, were a very helpful tool for beam-matching between the RTMs. Therefore a similar system was planned and constructed for the HDSM. A. Jankowiak et al. “Status Report on the Harmonics Double Sided Microtron of MAMI C”, this conference.
TUPCH035	Fine Spatial Beam Loss Monitoring for the ISIS Proton Synchrotron	1079
	S.J. Payne, S.A. Whitehead CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
	Beam loss detection at the ISIS synchrotron is achieved using a series of 3 and 4 metre long argon gas ionisation tubes placed around the inside track of the main ring and along the injector and extraction sections. Even with this level of diagnostics problems have occurred, for example, inside a main dipole within the accelerator ring where small concentrated areas of loss have resulted in severe damage to the RF shield. This type of loss cannot be easily resolved using the conventional argon gas system due to the length of the detectors and their distance from the vacuum vessel (around 2m). We report here the development of a compact beam loss monoitoring system which has been installed inside a dipole between the vacuum vessel and the main body of the dipole. The system comprises of six 150 sq. cm. (BC408) plastic scintillators connected to photo-multiplier tubes via fibre optic bundles. Measurements taken demonstrate that the new system can easily resolve complex beam loss patterns along the dipole while remaining robust to the high radiation environment. We also report here details of our PXI based data collection and display system.
TUPCH036	Modelling of Diagnostics for Space Charge Studies on the ISIS Synchrotron	1082
	B.G. Pine, S.J. Payne, C.M. Warsop CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
	The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It is based on a 50 Hz proton synchrotron which, once the commissioning of a new dual harmonic RF system is complete, will accelerate about 3.5·10¹³ protons per pulse from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. Transverse space charge is a key issue for both present and proposed upgrades to the machine, and is the focus of current R&D studies. Experiments on the ISIS ring are central to this work, therefore understanding and quantifying limitations in present and proposed diagnostics is essential. This paper presents work studying and modelling the ISIS residual gas profile monitors, including the effects of non-uniformity in sweep fields, space charge and images. Progress on related work looking at other important diagnostics, e.g., position and envelope monitoring, will also be summarised.
TUPCH037	Development of Emittance Scanner Software for ISIS	1085
	C.M. Thomas, D.C. Faircloth CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
	Horizontal and vertical Faraday cup and slit scanners are used on ISIS, the 800MeV pulsed neutron source at the Rutherford Appleton Laboratory, to calculate the emittance of the beam. Software has been written in C++ to control the scanners, acquire and display beam data and compute an emittance value for the beam. The software allows the user more control, and has the ability to scan over a wider range, than was previously available.
TUPCH038	Beam Loss Monitoring and Machine Protection Designs for the Daresbury Laboratory Energy Recovery Linac Prototype	1088
	S.R. Buckley, R.J. Smith CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Daresbury Laboratory is currently constructing an energy recovery linac prototype (ERLP). This is to carry out the necessary research and development of the technology of photo-cathode electron guns and superconducting linacs so that a fourth generation light source (4GLS) can be designed and constructed. Beam loss monitoring and machine protection systems are vital areas for the successful operation of the ERLP. These systems are required, both for efficient commissioning and for hardware protection during operation. This paper gives an overview of the system requirements, options available and details of the final design specification.
TUPCH039	A Phase Space Tomography Diagnostic for Pitz	1091
	D.J. Holder, B.D. Muratori CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire F.E. Hannon Jefferson Lab, Newport News, Virginia S. Khodyachykh, A. Oppelt DESY Zeuthen, Zeuthen
	The Photo Injector Test Facility at DESY in Zeuthen (PITZ) is a European collaboration developing RF photocathode electron guns for light source and linear collider projects. As part of the collaborative work being partially funded by the EU's FP6 programme, CCLRC Daresbury Laboratory and DESY are designing and building a phase space tomography diagnostic based on a set of multiple quadrupoles and view screens. In order to measure the beam emittance, four screens with intermediate quadrupole doublets will be used. The equipment will be installed and tested at PITZ as part of the facility upgrade presently ongoing. Following simulations of the gun using the ASTRA code at a range of energies, simulations of the electron beam parameters through the matching and tomography sections must be undertaken in order to specify the optimum arrangement of magnets and screens.
TUPCH041	Electro-optic Diagnostics on the Daresbury Energy Recovery Linac	1094
	P.J. Phillips, W.A. Gillespie University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire A. MacLeod UAD, Dundee
	An electro-optic longitudinal bunch profile monitor is being implemented on the 4GLS prototype energy recovery linac (ERL/p) at Daresbury Laboratories and will be used both to characterise the electron bunch and to provide a testbed for electro-optic techniques. The electro-optic station is located immediately after the bunch compressor, and within the FEL cavity; its location allows it to draw on nearby beam profile monitors and CTR and CSR diagnostics for calibration and benchmarking. We discuss the implementation and planned studies on electro-optic diagnostics with this diagnostic station.
TUPCH042	The Optical System for a Smith-Purcell Experiment at 45MeV	1097
	V. Blackmore, W.W.M. Allison, G. Doucas, C. Perry OXFORDphysics, Oxford, Oxon P.G. Huggard CCLRC/RAL, Chilton, Didcot, Oxon M.B. Johnston University of Oxford, Clarendon Laboratory, Oxford B. Redlich, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein
	Smith-Purcell (SP) radiation has been used to investigate the longitudinal profile of a 45MeV, picosecond long bunched beam at the FELIX facility, FOM Institute. The three important optical elements that made this experiment possible were (i) high quality optical filters, (ii) nonimaging light concentrators, (iii) and a system to rapidly change between gratings.
TUPCH043	Observations of the Longitudinal Electron Bunch Profile at 45MeV Using coherent Smith-Purcell radiation	1100
	G. Doucas, V. Blackmore, B. Ottewell, C. Perry OXFORDphysics, Oxford, Oxon P.G. Huggard CCLRC/RAL, Chilton, Didcot, Oxon M.B. Johnston University of Oxford, Clarendon Laboratory, Oxford M.F. Kimmitt University of Essex, Physics Centre, Colchester B. Redlich, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein
	Coherent Smith-Purcell (SP) radiation has been used to determine the longitudinal profile of the electron bunch at the FELIX facility, FOM Institute. Far-infrared radiation was detected using a simple, compact arrangement of 11 pyroelectric detectors. Background radiation was suppressed through the use of high quality optical filters, and an efficient light collection system. The measured bunch profile was most closely in agreement with 90% of the particles contained within 5.5ps, with an approximately triangular temporal profile.
TUPCH044	Turn-by-turn Data Acquisition and Post-processing for the Diamond Booster and Storage Ring	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	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	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	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.
TUPCH048	A Study of Emittance Measurement at the ILC	1115
	G.A. Blair, I.V. Agapov, J. Carter, L. Deacon Royal Holloway, University of London, Surrey D.A.-K. Angal-Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire L.J. Jenner Cockcroft Institute, Warrington, Cheshire M.C. Ross, A. Seryi, M. Woodley SLAC, Menlo Park, California
	The measurement of the ILC emittance in the ILC beam delivery system and the linac is simulated. Estimates of statistical and machine-related errors are discussed and implications for related diagnostics R&D are inferred.
TUPCH049	Proposal for a Fast Scanning System Based on Electro-optics for Use at the ILC Laser-wire	1118
	A. Bosco, G.A. Blair, S.T. Boogert, G.E. Boorman, L. Deacon, C. Driouichi, M.T. Price Royal Holloway, University of London, Surrey
	Electro-optic devices open the possibility of ultra-fast scanning systems for use in intra-train scanning at the ILC, where scanning rates in excess of 100 kHz may be required. A first study of the possibilities is presented together with the first results from a prototype system.
TUPCH050	Beam Profile Measurements with the 2-D Laser-wire	1121
	G.A. Blair, I.V. Agapov, S.T. Boogert, G.E. Boorman, A. Bosco, J. Carter, C. Driouichi, M.T. Price Royal Holloway, University of London, Surrey K. Balewski, H.-C. Lewin, F. Poirier, S. Schreiber, K. Wittenburg DESY, Hamburg N. Delerue, D.F. Howell OXFORDphysics, Oxford, Oxon T. Kamps BESSY GmbH, Berlin
	A new laser-wire system has been installed at the PETRA ring at DESY, Hamburg. The system is set up to scan in two dimensions using piezo-driven mirrors and employs a newly acquired injection seeded Q-switched laser. The system is described and first results are presented.
TUPCH052	Turn by Turn Measurements at DAFNE Based on the Libera Beam Position Processor	1124
	A. Stella, M. Serio INFN/LNF, Frascati (Roma)
	The BPM detection electronics developed by Instrumentation Techonologies implements digital receivers technology to measure beam position from the amplitude of pick-up signals. Besides the closed orbit mode, the Libera module can be operated also in the Turn-by-Turn mode. Operational experience with Libera at DAFNE, the Frascati e⁺ e^- collider, has been focused on this functionality. Data obtained from DAFNE have been processed with well established extraction algorithms to accurately measure the betatron tunes from a small number of turns, providing instantaneous information on tune variations occurred also in fast damped decays after a kick. Hardware and software implementation together with experimental data are reported.
TUPCH053	Bunch Length Characterization Downstream from the Second Bunch Compressor at FLASH DESY, Hamburg	1127
	E. Chiadroni INFN-Roma II, Roma
	The characterization of the longitudinal density profile of picosecond and sub-picosecond relativistic particle bunches is a fundamental requirement in many particle accelerator facilities, since knowledge of the characteristics of the accelerated beams is of utmost importance for the successful development of the next generation light sources and linear colliders. The development of non-intercepting beam diagnostics is thus necessary to produce and control such beams. First experimental evidences of the non-intercepting nature of diffraction radiation diagnostics are given. The longitudinal bunch distribution downstream of the second bunch compressor of the DESY TTF VUV-FEL has been reconstructed using a frequency-domain technique based on the autocorrelation of coherent diffraction radiation. Due to the low and high frequency suppression, introduced by the experimental apparatus, only a portion of the CDR spectrum participates to the reconstruction of the longitudinal bunch profile. The knowledge of the system frequency response is then crucial in order to correct the results and extrapolate a bunch shape as close as possible to the real one.
TUPCH054	Upgrade of Signal Processing of the BPM System at the SPring-8 Storage Ring	1130
	T. Fujita, S. Sasaki, M. Shoji, T. Takashima JASRI/SPring-8, Hyogo-ken
	SPring-8 is a third generation synchrotron light source, which is operated stably with top-up mode and with optics of low emittance mode. Along with stabilization of electron beam orbit in the ring, upgrading of the BPM system has also been required. We have developed a new signal processing circuit for COD measurement with a target of a few microns of position resolution at 1 kHz band-width and a few hundreds per second to take beam position of all BPMs. In the new circuit, a multiplexing method is employed and the IF frequency is directory detected with a 2MSPS 16-bit ADC. The digitized signal is processed with DSP to obtain beam position. Analog components of the circuit are equipped in a temperature controlled cabinet in order not to be affected by fluctuation of ambient temperature. In this paper we report schematics and performance of the new circuit, e.g., dependence of position resolution on measurement band-width and long time stability, etc. In addition, we briefly describe possibility of fast orbit measurement as a further application of the circuit.
TUPCH055	Beam Phase Measurement of Stored Bunch	1133
	T. Ohshima, A. Yamashita JASRI/SPring-8, Hyogo-ken M. Yoshioka SES, Hyogo-pref.
	We developed a system to measure synchronous phase angles for all bunches stored in the storage ring using an oscilloscope with high sampling rate. Precise phase measurement of specific bunch is required from the synchrotron radiation (SR) users, especially from the time resolved spectroscopy users. In a pump and probe experiment, the trigger timing for pumping laser should be precisely adjusted to the probe SR light. The timing of SR light is affected by the accelerating RF voltages, filling pattern, bunch currents, gap positions of insertion devices and so on. At the SPring-8, the bunch currents and the synchronous phase angles for all stored bunches can be measured within 30seconds using newly developed system. The precision of the phase angle is less than 8ps. We are now preparing to deliver the information of synchronous phase angle to SR users. The detail of the measurement system and achieved performance will be presented.
TUPCH056	A Simpler Method for SR Interferometer Calibration	1136
	J.W. Flanagan, H. Fukuma, S. Hiramatsu, H. Ikeda, T. Mitsuhashi KEK, Ibaraki
	Previous methods of performing absolute calibration of the SR interferometer used at KEKB (measuring mirror distortion with a pinhole mask, virtual beam broadening via local bumps, physical beam broadening via dispersion bumps) are very time-consuming, and require dedicated machine time to take the necessary data. We report on a new, simpler method we have developed, wherein we create small local bumps at the SR source point and observe the resulting shifts in the phase of the interference fringes. From these data we can calibrate the total magnification of the system, including the effects of mirror distortion. The calibration data can be taken in a very small amount of time (tens of minutes), and in parallel with physics running, without stopping the beam-size measurement system or interfering with its use for luminosity tuning. By taking the calibration data at different beam currents and correlating the magnification at each current with the appropriate interference pattern fit parameters, we can also obtain the parameters needed for real-time mirror distortion correction.
TUPCH057	A Diagnostic System for Beam Abort at KEKB	1139
	H. Ikeda, K. Akai, J.W. Flanagan, T. Furuya, S. Hiramatsu, M. Suetake, Y. Suetsugu, M. Tobiyama, T. Tsuboyama KEK, Ibaraki S. Stanic Tsukuba University, Ibaraki
	A controlled beam abort system has been installed at KEKB for the protection of the hardware components of the accelerator and detector from damage by ampere-class beam currents. In order to identify the reason for each abort and optimize the abort system to handle each type of problem as well as improve machine operation, a diagnostic system has been developed. Fast signals, such as beam currents, accelerating voltages of the RF cavities and beam loss monitor signals from PIN photo-diodes are recorded and analyzed by a data logger system with a high sampling rate at the moment of each abort. Beam oscillations, radiation dose at the detector and vacuum pressure are also examined to classify the reasons for beam loss and aborts. Statistics and typical examples of these aborts will be discussed.
TUPCH058	Very Small Beam Size Measurement by Reflective SR Interferometer at KEK-ATF	1142
	T. Naito, T. Mitsuhashi KEK, Ibaraki
	An SR interferometer with the Herschelian reflective optics has been developed for the measurement of several um beam size. The chromatic aberration of the optical system applied in the SR interferometer limits the resolution of SR interferometer. We used objective lens of the SR interferometer by a focusing mirror. For the convenience of observation of the interferogram, we applied Herschelian arrangement of the optics. The measured vertical beam size was less than 5um and the estimated vertical emittance was 1x10-11m at the KEK-ATF damping ring.
TUPCH059	Dual-mode Beam Current Monitor	1145
	S. Ninomiya, T. Adachi, S. Fukumoto KEK, Ibaraki S.H. Hatori, T. Kurita WERC, Tsuruga , Fukui
	A new type HEREWARD-transformer is developed. The original scheme connects pickup coil to the low impedance input of the amplifier to increase the time constant of the transformer. The new scheme employs negative impedance circuit which realizes perfect cancellation of the coil resistance. Therefore DC component of the beam current can be observed. Since number of winding of the pick up coil is only 100-turns, therefore by using the original scheme with a fast operational amplifier, the transformer can be operated at fast CT mode. Thus the dual mode operation can be realized by single core; the first mode is the slow beam intensity monitor, and the second is a fast response transformer. This operation mode realizes an accurate observation of the beam injection process. In order to make installation easy, the core is divided into two pieces. The magnetic shield from bending field is also installed. This monitor is developed at KEK, and installed into the accelerator at the WAKASA WAN Energy Research Center.
TUPCH060	Beam Collimator System in the J-PARC 3-50BT Line	1148
	M.J. Shirakata, H. Oki, T. Oogoe, Y. Takeuchi, M. Yoshioka KEK, Ibaraki
	For the J-PARC 50 GeV Main Ring Synchrotron (MR), the design beam emittance is 54 pi mm mrad. On the other hand, the 3 GeV beam from the Rapid Cycling Booster Synchrotron (RCS) may have a large halo component upto 216 pi mm mrad. In order to absorb the halo component, a beam collimator system will be installed in the beam transport line called as the 3-50BT, which connects the RCS and the MR. From the view of the hands-on maintenance, high endurance structure is adopted. The beam collimator design including the beam optics is reported in this paper.
TUPCH061	Installation of Beam Monitor Sensors in the LINAC Section of J-PARC	1151
	S. Sato, H. Ao, T. Tomisawa, A. Ueno JAEA/LINAC, Ibaraki-ken H. Akikawa JAEA, Ibaraki-ken Z. Igarashi, S. Lee KEK, Ibaraki
	In the LINAC section of J-PARC, we have several type of sensors of monitor, i.e, Beam Position Monitor, Beam Profile Monitor, Beam Size Monitor, Current Monitor, Beam Phase Monitor, Beam Loss Monitor. Those sensors are being installed currently. The procedures, remarks during the installation, status are described in this paper. As an examle, the beam postion monitors are one of sensors which are taken cared intensively for their positioning on their housing quadrupole magnet, then our cares during their installation are described .
TUPCH062	Synchrotron Radiation Diagnostics for the NSLS Booster	1154
	T.V. Shaftan, I. Pinayev BNL, Upton, Long Island, New York
	We developed an optical diagnostics system for the NSLS booster-synchrotron utilizing the synchrotron radiation from the dipole magnet. MATLAB based software allows to study the electron beam properties along the energy ramp. The trajectory, beam sizes and coupling at the different instants of time are retrieved from the analysis of the electron beam image. In the paper we present the system layout, as well as experimental results and upgrade plans.
TUPCH063	Novel Method for Beam Dynamics using an Alpha Particle Source	1157
	A. Sato, M. Aoki, Y. Arimoto, I. Itahashi, Y. Kuno, T. Oki, M. Yoshida Osaka University, Osaka
	PRISM is a future muon source which would provide high intense, monochromatic and pure muon beams. In order to achieve such muon beams we use a technique called Phase Rotation using an FFAG ring (PRISM-FFAG). The PRISM-FFAG ring is now under construction in Osaka university. The Commissioning will start in JFY 2007. In order to investigate the dynamical performances of the FFAG before the actual commissioning, we propose a novel experimental method. The principle of the method and its application to PRISM-FFAG will be described in this paper.
TUPCH064	Beam-based Alignment Strategy for the Group Controlled Magnets System	1160
	N. Hayashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Lee, T. Toyama KEK, Ibaraki
	The beam based alignment of the beam position monitor (BPM) becomes an important tool to reduce the closed orbit distortion (COD) in the recent accelerator. Normally, it requires the independent control of the quadrupole field. Changing the current of a quadrupole magnet, one would find the unperturbed position. However, the J-PARC Rapid-Cycling Synchrotron (RCS) has seven quadrupole families and only group of each family can be controlled simultaneously. There is neither separate power supplies nor auxiliary coil windings on each individual magnet. A similar alignment procedure is applicable for the coupled-controlled magnet system, but it becomes very complicated. For the simplest case, three magnets grouped together, four different beam orbits have to be measured at three different BPM locations. The method and some simulation results for J-PARC/RCS case will be presented in this report.
TUPCH065	A Prototype of Residual Gas Ionization Profile Monitor for J-PARC RCS	1163
	K. Satou, N. Hayashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Lee, T. Toyama KEK, Ibaraki
	A prototype of a residual gas ionization profile monitor (IPM) for J-PARC RCS has been developed. It consists of electrodes producing electric field to collect ionized ions/electrons, MCP as a signal read-out device, an electron generator to evaluate the gain balance of MCP channels, and a wiggler type magnet producing guiding field. The monitor has been installed in KEK-PS main ring and has been examined using proton beam. At the conference, recent preliminary results of experiments will be reported.
TUPCH067	Time-resolved Beam Emittance Measurement of Dragon-I Linear Induction Accelerator	1166
	G.J. Yang, S. Chen, X. Jiang, Z. Zhang CAEP/IFP, Mainyang, Sichuan
	A beam emittance diagnostic system of an intense pulsed electron beam (20MeV, 2.6kA, 80ns) based on optical transition radiation is developed. A gated CCD camera is used to get time-resolved result. We develop a timing system to avoid the time jitter, an anti-interference system to avoid the electromagnetic interference, and a C++ code to deal with the experimental data. The measured emittance is about 2000�Ð.mm.mrad, which is agree with the result of three gradient method.
TUPCH070	Development of Beam Profile Monitor for Cyclotron	1169
	K.-H. Park, S.-M. Hong, Y.G. Jung, D.E. Kim, H.-G. Lee, W.W. Lee PAL, Pohang, Kyungbuk D.H. An, J.-S. Chai, Y.S. Kim KIRAMS, Seoul B.-K. Kang POSTECH, Pohang, Kyungbuk
	A beam profile monitor was designed and fabricated to measure the beam shape of the cyclotron MC50 beam line at KIRAMS. The sensor module was made of 13 tungsten wires and they were assembled into an array type. The sensor wires whose diameter is 1 mm were placed in parallel with the incident beam, while they were placed in the perpendicular direction to the incident beam in the conventional method. Thus this monitor has a linear actuator to scan whole beam profile, which moves the sensor module from the dormant to measurement position or vice versa. The current output of each sensor was amplified using a trans-resistance amplifier which can measure input current in the range of 1 pA. The amplifier had a resolution of ~ 20 fA, the temperature drift of ~0.5 pA/°C, and the signal-to-noise ratio greater than 80 dB. Various test results of the amplifier and sensor module assembly are given in this paper. The measured current profiles of cyclotron beam line at KIRAMS are also given.
TUPCH071	Testing the Silicon Photomultiplier for Ionization Profile Monitor	1172
	S.V. Barabin, D.A. Liakin, A.Y. Orlov ITEP, Moscow P. Forck, T. Giacomini GSI, Darmstadt
	A new kind of photonic device is proposed to be used in the fast operating mode of the ionization profile monitor. A silicon photomultiplier device combines the advantages of photomultipliers and solid-state photo detectors. It provides high sensitivity, wide optical spectrum response, high bandwidth and absence of 1/f noise component. Those parameters are critical in the IPM with fast readout feature, which is developing in GSI in collaboration with ITEP, COOSY, MSU and CRYRING laboratories. Very first investigations were made to obtain detailed parameters of silicon photomultiplier. A testing layout and resulting performance data are presented in this publication.
TUPCH072	New Generation Streak Camera Design and Investigation	1175
	A.M. Tron LPI, Moscow T.V. Gorlov, I.G. Merinov MEPhI, Moscow
	The only method for electron bunch duration monitoring with a resolution in the order of 10 fs and less is the method of photochronography of the bunch incoherent radiation in the frequency range, for example, of visible light and at realizing streak camera with new principles of its operation. In the paper the streak camera design for measuring both the electron bunches and x-ray pulses duration with the mentioned temporal resolution is presented. The results of the camera investigation, with photoelectron dynamics simulation taking into account space-charge effect and impact of the surface roughness of a spherical photocathode of the 20-50 micrometers radius (forming a modulating gap of spherical configuration) on the camera resolution, are presented and discussed. A. M. Tron and I. G. Merinov. Method of bunch radiation photochronography with 10 femtosecond and less resolution. http://www.physics.ucla.edu/PAHBEB2005/talks/10oct2005/wg2/atron.pdf
TUPCH073	Study of Beam Energy Spread at the VEPP-4M	1178
	O.I. Meshkov, V. F. Gurko, A.D. Khilchenko, V. Kiselev, N.Yu. Muchnoi, A.N. Selivanov, V.V. Smaluk, A. N. Zhuravlev BINP SB RAS, Novosibirsk
	The knowledge of beam energy spread is necessary for the experimental program of the VEPP-4M collider. In this report we discuss the application of optical diagnostics for measurement of this value. The diagnostics is based on multi-anode photomultiplier and provides information about betatron and betetron frequencies of electron beam. The beam energy spread is derived from the spectra of synchrotron oscillation. The results, obtained with this method, are compared with data, provided by Compton backscattering technique. O. I. Meshkov et al. Application of the beam profile monitor for VEPP-4M tuning. Proc. of DIPAC '05, June 6 - 8, 2005, Lyon, France, POM008.
TUPCH074	Fast and Precise Beam Energy Monitor Based on the Compton Backscattering at the VEPP-4M Collider	1181
	N.Yu. Muchnoi, S.A. Nikitin, V.N. Zhilich BINP SB RAS, Novosibirsk
	Accurate knowledge of the colliding beam energies is essential for the current experiments with the KEDR \cite{KEDR} detector at the VEPP-4M collider. Now the experimental activity is focused on the new precise measurement of the tau-lepton mass by studying the behavior of the tau production cross-section near the reaction threshold. To achieve the desired quality of the experiment, an on-line beam energy monitoring by the Compton backscattering of laser light was performed. This approach is found to be a very good supplement to rare energy calibrations by the resonant depolarization technique, saving the beam time for luminosity runs. The method itself does not require electron beam polarization and additionally allows one to measure the electron beam energy spread. The achieved accuracy of the method in the beam energy range 1.7–1.9 GeV is 60 keV.
TUPCH075	Dependence of the Electron Beam Polarization Effect in the Intra-beam Scattering Rate on the Vertical Beam Emittance	1184
	S.A. Nikitin, I.B. Nikolaev BINP SB RAS, Novosibirsk
	Measurement of the Intra-beam scattering rate is applied in the resonant depolarization technique to detect beam polarization in electron/positron storage rings. A depolarization jump in the counting rate of scattering particles occurs at the instant when the beam becomes unpolarized due to fulfillment of the external spin resonance condition. The magnitude of the jump depends on polarization quadratically. It also depends on some other beam parameters as well as the position of counters relative to the beam orbit. A larger jump implies higher accuracy in absolute calibration of particle energy because the latter is proportional to the spin precession frequency. In contrast to an ordinary one-dimensional approach, we calculate the magnitude of jump subject to, among other things, the vertical component of relative velocity in particle collisions inside the beam. For this purpose, the transverse momentum distribution function is properly modified. Calculations performed for the VEPP-4M storage ring-collider show that the jump may depend significantly on the ratio between the vertical and radial beam emittance. We present results of our recent experiments on study of this dependence.
TUPCH077	Beam Phase Measurement in a 200 MeV Cyclotron	1187
	J.L. Conradie, A.H. Botha, P.J. Celliers, J.L.G. Delsink, D.T. Fourie, P.T. Mansfield, P.F. Rohwer, M.J. Van Niekerk iThemba LABS, Somerset West J. Dietrich, I. Mohos FZJ, Jülich
	New phase measuring equipment is being planned for the K 200 variable frequency, separated-sector cyclotron at iThemba LABS near Cape Town. A commercial lock-in amplifier is used to measure the beam phase over the full radial range. Measurements are made at the third and fifth harmonics of the main RF frequency to limit pick-up from the flat-topping and main dees. Computer-generated signals, with phase and amplitude control, at the same harmonics, are used to cancel the signals coupled from the dees to the phase probes. In addition the signals without beam are vectorially subtracted from those with beam to enhance the sensitivity and accuracy. Results of measurements, using these techniques, on existing phase probes in the cyclotron, will be presented.
TUPCH078	BPM Design for the ALBA Synchrotron	1190
	F. Pérez, A. Olmos ALBA, Bellaterra T.F. Günzel ESRF, Grenoble
	ALBA is a 3 GeV, low emittance, 3rd generation synchrotron light source that is in the construction phase in Cerdanyola, Spain. Vertical beam sizes down to a few microns will require beam stabilities on the submicron level. The BPM has to be designed in order to provide reliable and accurate beam position readings. Simulation and computational codes have been used to optimise, for a given vacuum chamber dimension, the BPM design. The optimisation has taken into account the usual sensitivity and intrinsic resolution parameters, but as well, the wakefield loss factor of the buttons. Due to the small vertical vacuum chamber dimension and the high design current, the beam power deposited in the buttons is becoming a concern due to the thermal deformation effects that can introduce errors at the submicron level. A compromise between a higher intrinsic resolution from one side, and a low power deposited by the beam in the buttons from the other, define the final buttons dimensions.
TUPCH079	Characterisation of the MAX-II Electron Beam: Beam Size Measurements	1193
	M. Sjöström, H. Tarawneh, E.J. Wallén MAX-lab, Lund
	Over the last year investigations of the MAX-II electron beam characteristics have been made. Examples of investigated parameters include the beam size, bunch length, vacuum and Touschek lifetimes, and the machine functions. Several upgrades of the MAX II ring have been performed since the commissioning 1995 like a new 100 MHz RF system with a 500 MHz Landau cavity, exchanged injector, and a variety of insertion devices. There is hence a need to systematically characterize the present machine. This systematic characterisation is now underway and this article describes details of the beam size measurements.
TUPCH080	Bunched Beam Current Measurements with 100 pA rms Resolution at CRYRING	1196
	A. Paal, A. Simonsson MSL, Stockholm J. Dietrich, I. Mohos FZJ, Jülich
	In CRYRING molecular beams with currents down to 1 nA are used for experiments. To extend the rms resolution of the bunched beam current measurements down to 100 pA, a BERGOZ Integrating Current Transformer (ICT) and one of the the capacitive pick-up's sum signal are integrated simultaneously. The absolute calibration of the pick-up integrator signal is carried out at the end of the acceleration stage, during 20-60 ms. The ion beam current can be measured over a pulse width range of 100 ns to 15 us with a 20-60% bunch duty cycle. For both detectors, low noise amplifiers and a differential input double integrator have been designed. A programmable phase shifter allows measurement of the beam current during the acceleration of the ions, generating a gate signal with proper phase for the integrators in the 30 kHz-3 MHz frequency range. The bandwidth of the integrators used is 100 Hz.
TUPCH081	Technical Aspects of the Integration of the Optical Replica Synthesizer for the Diagnostics of Ultra-short Bunches in FLASH at DESY	1199
	V.G. Ziemann UU/ISV, Uppsala N.X. Javahiraly, P. van der Meulen FYSIKUM, AlbaNova, Stockholm University, Stockholm M. Larsson Stockholm University, Department of Physics, Stockholm E. Saldin, H. Schlarb, E. Schneidmiller, A. Winter, M.V. Yurkov DESY, Hamburg
	In this paper we present an overview of current status of the Optical Replica synthesizer at DESY. The method is based on producing an "optical copy" of the electron bunch with its subsequent analysis with optical techniques. To this end, a near-IR laser beam is superimposed on the electron beam in the first undulator of an optical klystron. In the following dispersive section the laser-induced energy modulation is transformed into a density modulation . The modulated electron bunch then produces a strong optical pulse in the second undulator. Analysis of this near-IR pulse (the optical copy) then provides information about the profile, the slice emittance and the slice energy spread of the electron bunch. We discuss the implementation of such a measurement set-up at the FLASH facility at DESY and investigate the influence of various parameters on the performance of the device. Topics we address include the dispersive chicane, as well as the requirements for the seed laser pulses and the detection and analysis of the near-IR pulse. E. Saldin, et al. "A simple method for the determination of the structure of ultrashort relativistic electron bunches," Nucl. Inst. and Methods A 539 (2005) 499.
TUPCH082	The EuroTeV Confocal Resonator Monitor Task	1202
	V.G. Ziemann, T. J. C. Ekelof, A. Ferrari, M. A. Johnson, E. A. Ojefors, A. B. Rydberg UU/ISV, Uppsala F. Caspers CERN, Geneva
	We describe the progress in the analysis of the confocal resonator monitor task which is part of the diagnostics workpackage of EuroTeV. The initial design was analyzed both numerically and experimentally and found limitations. We therefore digressed from strict confocality and report the numerical analysis and S-parameter measurements of a modified design. Furthermore, we discuss the mechanical design needed for planned tests with beam in CTF3 which requires integration of the monitor into the beam pipe, damping of trapped modes, and frequency tunability.
TUPCH083	Time-resolved Spectrometry on the CLIC Test Facility 3	1205
	T. Lefevre, C.B. Bal, H.-H. Braun, E. Bravin, S. Burger, R. Corsini, S. Doebert, C.D. Dutriat, F. Tecker, P. Urschütz, C.P. Welsch CERN, Geneva
	The high charge (>6microC) electron beam produced in the CLIC Test Facility 3 (CTF3) is accelerated in fully loaded cavities. To be able to measure the resulting strong transient effects, the time evolution of the beam energy and its energy spread must be measured with at least 50MHz bandwidth. Three spectrometer lines were installed all along the linac in order to control and tune the beam. The electrons are deflected by a dipole magnet onto an Optical Transition Radiation (OTR) screen, which is observed by a CCD camera. The measured beam size is then directly related to the energy spread. In order to provide time-resolved energy spectra, a fraction of the OTR photons is sent onto a multichannel photomultiplier. The overall set-up is described, special focus is given to the design of the OTR screen with its synchrotron radiation shielding. The performance of the time-resolved measurements are discussed in detail. Finally, the limitations of the system, mainly due to radiation problems, are discussed.
TUPCH084	Expected Signal for the TBID and the Ionization Chambers Downstream of the CNGS Target Station	1208
	L. Sarchiapone, A. Ferrari, E. Gschwendtner, M. Lorenzo Sentis CERN, Geneva
	Downstream the carbon graphite target of the CNGS (CERN Neutrinos to Gran Sasso) facility at CERN it has been decided to install a secondary emission monitor called TBID (Target Beam Instrumentation Downstream) monitor to measure the multiplicities and the left/right as well as up/down asymmetries of secondary particles from target. Calculations show that the titanium windows used to close off the TBID vacuum tank might not withstand the highest beam intensities with small spot sizes expected at CNGS, in case the proton beam accidentally misses the 4-5 mm diameter target rods. Therefore it has been suggested to place two ionisation chambers as a backup for the TBID located left and right of the TBID monitors. Monte Carlo simulations with the particle transport code FLUKA were performed firstly to obtain the fluence of charged particles in the region of interest and secondly to estimate the induced radioactivity (noise) in this area. This allows to assess the actual signal/noise situation and thus to determine the optimal position (lateral displacement with respect to the beamline) of the ionisation chambers. This document presents the results of these calculations.
TUPCH086	Precision Beam Timing Measurement System for CLIC Synchronization	1211
	J.P.H. Sladen, A. Andersson CERN, Geneva
	Very precise synchronization between main and drive beams is required in CLIC to avoid excessive luminosity loss due to energy variations. One possibility to accomplish this would be to measure and correct the drive beam phase. The timing reference for the correction could be the beam in the transfer line between the injector complex and the main linac. The timing of both main and drive beams will have to be measured to a precision in the region of 10 fs. The aim is to achieve this by means of a beam measurement at 30 GHz with the signal mixed down to an intermediate frequency (IF) for precise phase detection. The RF and IF electronics are being developed and tests will be carried out in CTF3.
TUPCH087	Beam Diagnostics with Schottky Noise in LEIR	1214
	J. Tan, G. Tranquille CERN, Geneva
	The high density Lead ion beams, needed for LHC, are obtained in the Low Energy Ion Ring (LEIR) at CERN by multi-turn injection followed by electron cooling and stacking. During this injection and stacking phases where the circulating beam is unbunched, diagnostics with Schottky noise are used for probing essential beam parameters, such as tune, momentum spread, emittance and their evolution with time� The hardware facility and first results obtained during the recent commissioning of LEIR are described.
TUPCH088	High Dynamic Range Beam Profile Measurements	1217
	C.P. Welsch, E. Bravin, B. Burel, T. Lefevre CERN, Geneva T. Chapman, M.J. Pilon Thermo, Liverpool, New York
	In future high intensity, high energy accelerators, beam loss has to be minimized to maximize performance and minimize activation of accelerator components. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Measurements based on optical transition radiation (OTR) provide an interesting opportunity for high resolution measurements of the transverse beam profile. In order to be applicable for measurements within the beam halo region, it is of utmost importance that a high dynamic range is covered by the image acquisition system. The existing camera system as it is installed in the CLIC Test Facility (CTF3) is compared to a step-by-step measurement with a photo multiplier tube (PMT) and measurements with a cooled charge injection device (CID) camera. The latter acquisition technique provides an innovative and highly flexible approach to high dynamic range measurements and is presented in some detail.
TUPCH089	Investigations of OTR Screen Surfaces and Shapes	1220
	C.P. Welsch, E. Bravin, T. Lefevre CERN, Geneva
	Optical transition radiation (OTR) has proven to be a flexible and effective tool for measuring a wide range of beam parameters, in particular the beam divergence and the transverse beam profile. It is today an established and widely used diagnostic method providing linear real-time measurements. Measurements in the CLIC Test Facility (CTF3) showed that the performance of the present profile monitors is limited by the optical acceptance of the imaging system. In this paper, two methods to improve the systems' performance are presented and results from measurements are shown. First, the influence of the surface quality of the OTR screen itself is addressed. Several possible screen materials have been tested to which different surface treatment techniques were applied. Results from the measured optical characteristics are given. Second, a parabolic-shaped screen support was investigated with the aim of providing an initial focusing of the emitted radiation and thus to reduce the problem of aperture limitation. Measured and calculated emission distributions are presented.
TUPCH090	Electron Beam Profile Measurements with Visible and X-ray Synchrotron Radiation at the Swiss Light Source	1223
	Å. Andersson, M. Rohrer, V. Schlott, A. Streun PSI, Villigen O.V. Chubar SOLEIL, Gif-sur-Yvette
	Two different methods of beam profile measurements using a) visible-to-UV range synchrotron radiation b) X-ray synchrotron radiation have been realized in a single diagnostics beam line at the Swiss Light Source. While the visible-to-UV part uses a focusing lens to create an image of the electron beam cross section, the X-ray part makes use of the pinhole camera principle. In the visible-to-UV case the vertically polarized synchrotron radiation renders an image heavily influenced by inherent emission and diffraction effects of synchrotron radiation. This turns out to be an advantageous influence in order to determine ultra small beam profiles. For each of the two methods practical point-spread function measurements, including all beam line components, and high-precision wave-optics based calculations (SRW code) of the synchrotron light characteristics were performed to ensure correct interpretation of the measured profiles. Results from both monitors will be presented to allow comparison.
TUPCH092	Commissioning of a New Digital BPM System for the PSI Proton Accelerators	1226
	B. Keil, P.-A. Duperrex, M. U. Müller PSI, Villigen
	A new digital beam position monitor (DBPM) system has been developed and successfully tested at the PSI proton accelerators. The DBPM hardware consists of an analogue RF front-end (RFFE), a VMEbus backplane module (VBM), and the PSI VME PMC Carrier board (VPC). The RFFE combines the 2nd RF harmonic (101.26 MHz) beam signals of pickup coils with a 101.31 MHz pilot signal. The RFFE output signals are undersampled and down-converted to base-band (no analogue mixer) by ADCs and DDCs (Direct Digital Downconverters) on the VBM. The DDCs send the digitised beam and pilot signal amplitudes to a Virtex2Pro FPGA on the VPC board. The FPGA calculates the beam positions at different averaging rates, checks interlock limits, and provides triggered storage of beam position waveforms. Furthermore, the FPGA performs automatic gain control of voltage-controlled amplifiers (VCAs) of RFFE and VBM. By continuous normalisation of beam to pilot signal, nonlinearities and temperature drifts of the electronics are eliminated. Compared to the old analogue BPM electronics, the new DBPMs offer an increased dynamic range (0.2 μA to 2 mA instead of 5 μA to 2 mA) and larger bandwidth (10 kHz instead of 10 Hz).
TUPCH094	THz Diagnostic for the Femtosecond Bunch Slicing Project at the Swiss Light Source	1229
	V. Schlott, D. Abramsohn, P. Beaud, G. Ingold, P. Lerch PSI, Villigen
	Interaction of electron bunches with a femtosecond Ti:Sa laser beam along a modulator wiggler in the Swiss Light Source (SLS) storage ring results in an energy modulation of the electron beam on the length scale of the laser pulse. While high energy photon pulses (3 18 keV, ~ 100 fs long) are produced by an in-vacuum undulator (radiator) and used for time resolved experiments within the SLS femtosecond bunch slicing project, coherent synchrotron radiation (CSR) emitted by the adjacent bending magnet in the THz-regime is used for longitudinal slicing diagnostics and monitoring of slicing efficiency. This paper describes the simulation and layout of the THz-diagnostic beamline and presents first time and spectrally resolved measurements with the longitudinal slicing diagnostics, which has been set-up for the SLS “femto-slicing” project.
TUPCH095	Status of Synchrotron Radiation Monitor at TLS	1232
	C.H. Kuo, J. Chen, K.-T. Hsu, S.Y. Hsu, K.H. Hu, D. Lee, C.-J. Wang NSRRC, Hsinchu
	Synchrotron radiation monitor of the Taiwan Light Source have been upgraded recently. Improvement of optics and modelling was performed to improve accuracy of measurement for small beam size. Synchrotron light interferometer is implemented for complementary measurement. IEEE-1394 digital CCD camera is used to improve image transmission quality, camera remote control and to extend dynamic range. Intensify gated camera are included in this upgrade for dynamic property observation of the stored beam. Functionality enhancement of image analysis is also supported. Efforts and achievements will be summarized in this report.
TUPCH096	High-intensity Bremsstrahlung Monitoring System for Photonuclear Technologies	1235
	V.L. Uvarov, S.P. Karasyov, V.I. Nikiforov, R.I. Pomatsalyuk, V.A. Shevchenko, I.N. Shlyakhov, A.Eh. Tenishev, Yu.V. Zhebrovsky NSC/KIPT, Kharkov
	The realization of promising photonuclear technologies (a soft technology for medical isotope production, radioactive waste handling, activation analysis, etc) calls for the sources of high-energy (Egamma>10MeV) and high-intensity (>=10E03W/cm2) photons. These sources may by obtained by converting a beam from a high-current electron Linac into bremsstrahlung. The method of combined activation of a set of foils that have different energy thresholds of the (gamma,n) reactions is proposed to determine the space-energy characteristics of such radiation. In each energy range the geometrical characteristics of the bremsstrahlung flux are reconstructed from the foil surface gamma-activity distribution. The last one is determined through one-dimensional scanning of the foils by a specially designed detecting head that includes a linear matrix of 16 collimated semiconductor detectors (CdZnTe; 2x2x2,mm). A preliminary analysis of the system geometry and applicability of the method was performed by computer simulation based on the PENELOPE software. A developed PC based measuring system with CAMAC interface is described.
TUPCH097	Instrumentation and Operation of a Remote Operation Beam Diagnostics Lab at the Cornell Electron-positron Storage Ring	1238
	R. Holtzapple, J.S. Kern, P.J.S. Stonaha Alfred University, Alfred, New York B. Cerio Colgate University, Hamilton, New York M.A. Palmer Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	Accelerator beam diagnostics are being modified at the Laboratory of Elementary Particle Physics (LEPP) at Cornell University for remote operation at nearby Alfred University. Presently, a streak camera used for longitudinal dynamics measurements on the Cornell Electron-Positron Storage Ring (CESR) is operational and measurements have been made from Alfred University [1]. In the near future, photomultiplier tube arrays for electron and positron vertical beam dynamics measurements will be remotely operated as well. In this paper, we describe instrumentation and operation of the remote beam diagnostics.
TUPCH098	Antiproton Momentum Distributions as a Measure of Electron Cooling Force at the Fermilab Recycler	1241
	D.R. Broemmelsiek, S. Nagaitsev Fermilab, Batavia, Illinois
	The Fermilab Recycler is a fixed 8GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. Electron cooling of high-energy antiprotons has recently been demonstrated at the Recycler. Antiproton beam Schottky signals were used to measure the antiproton momentum distribution at equilibrium between a calibrated broadband diffusion source and electron cooling. The large Recycler momentum aperture, the dependence of the electron cooling force as a function of the antiproton momentum deviation and the calibrated diffusion source combine to give a unique spectral measurement of the antiproton momentum beam distribution.
TUPCH100	Fiberoptics-based Instrumentation for Storage Ring Longitudinal Diagnostics	1247
	S. De Santis, J.M. Byrd, A. Ratti, M.S. Zolotorev LBNL, Berkeley, California Y. Yin Y.Y. Labs, Inc., Fremont, California
	Many beam diagnostic devices in today's synchrotron rings make use of the radiation emitted by the circulating particles. Such instruments are placed in close proximity of the accelerator, where in many instances they cannot be easily accessed for safety consideration, or at the end of a beamline, which because of its cost, can only move the light port a few meters away from the ring. We present a study on the coupling of synchrotron light into an optical fiber for all those application where the longitudinal properties of the beam are measured (i.e., bunch length, phase, intensity, etc.). By choosing an appropriate fiber it is possible to keep attenuation and dispersion at negligible values over a large bandwidth, so that this method would allow to have the diagnostic instruments directly in the control room, or wherever convenient, up to several hundred of meters away from the tunnel. This would make maintaining and replacing instruments, or switching between them, possible without any access to restricted areas. Additionally, the few components required to be near the ring (lenses and couplers) in order to couple the light into the fiber are intrinsically radiation-hard.
TUPCH101	Modeling of Ultrafast Streak Cameras	1250
	G. Huang, J.M. Byrd, J. Feng, H.A. Padmore, J. Qiang, W. Wan LBNL, Berkeley, California
	We present progress on modeling of streak camera with application to measurement of ultrafast phenomena. Our approach is based on treating the streak camera as a photocathode gun and applying modeling tools for beam optics, space charge, and electromagnetic fields. We use these models to compare with experimental results from a streak camera developed at the Advanced Light Source. Furthermore, we explore several ideas for achieving sub-100 fsec resolution.
TUPCH103	New Developments on Single-shot Fiber Scope	1253
	Y. Yin, X. Che Y.Y. Labs, Inc., Fremont, California
	New development has been done to reduce the noise and improve the stability of the single-shot fiber scope, which used an optical fiber recirculating delay line to regenerate the single-shot very short electrical pulse, so a sampling scope can recover the original signal. New measurements have been done and will be reported.
TUPCH105	Performance of a Nanometer Resolution BPM System	1256
	S. Walston, C.C. Chung, P. Fitsos, J.G. Gronberg LLNL, Livermore, California S.T. Boogert Royal Holloway, University of London, Surrey J.C. Frisch, J. May, D.J. McCormick, M.C. Ross, S. Smith, T.J. Smith SLAC, Menlo Park, California H. Hayano, Y. Honda, N. Terunuma, J. Urakawa KEK, Ibaraki Y.K. Kolomensky, T. Orimoto UCB, Berkeley, California A. Lyapin, S. Malton, D.J. Miller UCL, London R. Meller Cornell University, Department of Physics, Ithaca, New York M. Slater, M.T. Thomson, D.R. Ward University of Cambridge, Cambridge V.V. Vogel DESY, Hamburg G.R. White OXFORDphysics, Oxford, Oxon
	International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved – ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. The three BPMs are rigidly mounted inside an alignment frame on variable-length struts which allow movement in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a calibration algorithm which is immune to beam jitter. To date, we have been able to demonstrate a resolution of approximately 20 nm over a dynamic range of ± 20 microns. We report on the progress of these ongoing tests.
TUPCH106	Commissioning the SPEAR3 Diagnostic Beamlines	1259
	W.J. Corbett, C. Limborg-Deprey, W.Y. Mok, A. Ringwall SLAC, Menlo Park, California
	SPEAR 3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV laboratory. The pinhole camera images ~8 keV dipole radiation on a phosphor screen with a remote computer to capture digital profile images. The visible/UV beam line features an 8 mm high GlidCop 'cold finger' to remove the x-ray core of the beam. The remaining light is deflected horizontally onto an optical bench where it is focused via reflective (Cassegrain) or refractive optics. The visible beam is then split into branch lines for a variety of experimental applications. This paper describes the experimental arrangement, data processing algorithms and measurements obtained with both systems.
TUPCH108	Characterization of the PEP-II Colliding-beam Phase Space by the Boost Method	1262
	M. Weaver SLAC, Menlo Park, California W. Kozanecki CEA, Gif-sur-Yvette B.F. Viaud Montreal University, Montreal, Quebec
	We present a novel approach to characterize the colliding-beam phase space at the interaction point of the energy-asymmetric PEP-II B-Factory. The method exploits the fact that the transverse-boost distribution of e⁺ e^- –> mu+ mu- events reconstructed in the BaBar tracking system, reflects that of the colliding electrons & positrons. The average boost direction, when combined with the measured orientation of the luminous ellipsoid, determines the e⁺e^- crossing angles. Varying the horizontal direction of one beam with respect to the other in a controlled fashion allows to estimate the individual e⁺ and e^- horizontal IP beam sizes. The angular spread of the transverse boost vector provides an accurate measure of the angular spread of the incoming high-energy beam, confirming the presence of a significant beam-beam induced increase of this angular spread. In addition, the longitudinal dependence of the angular spread of the boost vector in the y-z plane allows to extract from the continuously-monitored boost distributions, a weighted average of the vertical IP beta-functions & emittances of the two beams representative of routine high-luminosity operation.
TUPCH109	Ion-related Phenomenon in UVSOR/UVSOR-II Electron Storage Ring	1265
	A. Mochihashi, K. Hayashi, M. Hosaka, M. Katoh, J. Yamazaki UVSOR, Okazaki Y. Hori KEK, Ibaraki Y. Takashima Nagoya University, Nagoya
	A vertical betatron tune shift depending on beam current under multibunch condition was observed in the UVSOR storage ring. Vertical tune increased as beam current decreased, and the slope of the tune shift depended on the condition of the vacuum in the ring. Such a change in vertical tune was explained by a change in the stability condition of trapped ions/* with the beam current. Based on a theoretical model*** that gives density of the trapped ions the experimental results were discussed via analytic and tracking calculations. Both the effect from the residual gas ions generated by scattering between high energy electrons and molecules and that from dissociated ions that come from secondary ionization processes have been discussed. In quest of the ion-related phenomenon in single-bunch condition, precise tune measurement has been also performed in the UVSOR-II storage ring. The experimental results in the single-bunch condition have been discussed. Precise measurement of vacuum pressure in the beam duct is a key issue of the ion-related phenomenon. A design of vacuum pressure measurement system via detecting residual gas fluorescence will be introduced in the presentation. R. D. Kohaupt. DESY Internal. Bericht No.H1-71/2 (1971). Y. Baconnier and G. Brianti. CERN Internal Report No.CERN/SPS/80-2(DI) (1980). **A. Mochihashi et al. Jpn. J. Appl. Phys. 44 (2005) 430.
TUPCH197	Low level RF System Development for the Superconducting Cavity in NSRRC	1477
	M.-S. Yeh, L.-H. Chang, F.-T. Chung, K.-T. Hsu, Y.-H. Lin, C. Wang NSRRC, Hsinchu
	The present low level system in NSRRC is based on analogy feedback control scheme. It provides feedback regulation on EM field, phase, and resonant frequency of the superconducting RF cavity. In order to address the required flexibility and improve diagnostic of the RF control system, a new digital low-level RF system based on Field Programmable Gate Array (FPGA) is proposed to be develop in house. The status of current analogy low level RF system and the specification of new digital FPGA based low level RF system are reposted herein.
THPPA01	High-precision Laser Master Oscillators for Optical Timing Distribution Systems in Future Light Sources	2747
	A. Winter, P. Schmüser, A. Winter Uni HH, Hamburg J. Chen, F.X. Kaertner MIT, Cambridge, Massachusetts F.O. Ilday Bilkent University, Bilkent, Ankara F. Ludwig, H. Schlarb DESY, Hamburg
	Abstract to be supplied
	Transparencies
THYFI01	Tevatron Ionization Profile Monitoring	2777
	A. Jansson, K. Bowie, T. Fitzpatrick, R. Kwarciany, C. Lundberg, D. Slimmer, L. Valerio, J.R. Zagel Fermilab, Batavia, Illinois
	Ionization Profile monitors have been used in almost all machines at Fermilab. However, the Tevatron presents some particular challenges with its two counter-rotating, small beams, and stringent vacuum requirements. In order to obtain adequate beam size accuracy with the small signals available, custom made electronics from particle physics experiments was employed. This provides a fast (single bunch) and dead-timeless charge integration with a sensitivity in the femto-Coulomb range, bringing the system close to the single ionization electron detection threshold. The detector itself is based on a previous Main Injector prototype, albeit with many modifications and improvements. The first detector was installed at the end of 2005, with a second detector to follow during the spring shutdown. The ultimate is to continuously monitor beam size oscillations at injection, as well as the beam size evolution during ramp and squeeze.
	Transparencies
THOBFI01	A Sub 100 fs Electron Bunch Arrival-time Monitor System for FLASH	2781
	F. Loehl, K.E. Hacker, F. Ludwig, H. Schlarb, B. Schmidt DESY, Hamburg A. Winter Uni HH, Hamburg
	The stability of free-electron lasers and experiments carried out in pump-probe configurations depends sensitively on precise synchronization between the photo-injector laser, low-level RF-systems, probe lasers, and other components in the FEL. A measurement of the jitter in the arrival-time of the electron bunch with respect to the clock signal of a master oscillator is, therefore, of special importance. For this task, we propose an arrival-time monitor based on a beam pick-up with more than 10GHz bandwidth which permits measurements in the sub 100 fs regime. The RF-signal from the beam pick-up is sampled by an ultra-short laser pulse using a broad-band electro-optical modulator. The modulator converts the electron bunch arrival-time jitter into an amplitude modulation of the laser pulse. This modulation is detected by a photo detector and sampled by a fast ADC. By directly using the laser pulses from the master laser oscillator of the machine, any additional timing jitter is avoided. In this paper we present the layout of the system and first experimental results.
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THOBFI02	Measurement of the Beam Profiles with the Improved Fresnel Zone Plate Monitor	2784
	H. Sakai, N. Nakamura ISSP/SRL, Chiba H. Hayano, T. Muto KEK, Ibaraki
	We present the recent progress of the FZP (Fresnel Zone Plate) beam profile monitor constructed at KEK-ATF damping ring. This monitor based on an X-ray imaging optics with two FZPs. In this monitor, the transverse electron beam image at bending magnet is twenty-times magnified by the two FZPs and detected on an X-ray CCD camera. Then the real-time and 2-dimentional transverse beam profiles can be obtained with non-destructive manner by using this monitor. The expected spatial resolution is less than 1 micro-meter. Recently, we install the new mechanical shutter to improve time resolution of the monitor and avoid the effects of the short-term movement of the beam or the monitor itself. By applying this shutter, the shutter opening time was reduced less than 1ms and the beam profile could be measured more accurately. In this paper, we report the new shutter performance and the measurement results of beam profiles by the improved FZP beam profile monitor. K. Iida, et al. Nucl. Instrum. Meth. A 506 (2003) 41-49.
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THOBFI03	Record-high Resolution Experiments on Comparison of Spin Precession Frequencies of Electron Bunches Using the Resonant Depolarization Technique in the Storage Ring	2787
	S.A. Nikitin, O. Anchugov, V.E. Blinov, A. Bogomyagkov, V.P. Cherepanov, G.V. Karpov, V. Kiselev, E. Levichev, I.B. Nikolaev, A.A. Polunin, E. Shubin, E.A. Simonov, V.V. Smaluk, M.V. Struchalin, G.M. Tumaikin BINP SB RAS, Novosibirsk
	The opportunity of performing an experiment on high precision comparison of the electron and positron anomalous magnetic moments following the VEPP-2M experiment is under study at the VEPP-4M storage ring. The record accuracy of 2x10-8 was obtained for comparison of spin precession frequencies in the experiment on resonant depolarization with simultaneously circulating electron bunches, two of them polarized and one unpolarized. It is the first time when the spreading of the spin precession frequency line (~5x10-7,) due to scattering of particle trajectories about the equilibrium orbit in a non-linear field of the storage ring, was presumably observed in experiments. We proposed and realized an RF scheme for controlled separation of the spin precession frequencies of two electron bunches; the first measurements using this scheme were made.
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