EPAC 2006 - List of Keywords

A B C D E F G H I K L M O P Q R S T U V W X

photon

Paper	Title	Other Keywords	Page
MOPCH044	Peculiarities of the Doppler Effect for Moving Radiative Particles in Dispersive Medium at Extreme Conditions	radiation	139
	M.V. Vysotskyy, V.I. Vysotskii National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev
	The features of Doppler effect for fast moving radiating particles with discrete energy levels spectrum (e.g. radiation at channeling) at parameters close or equal to extreme condition of Cherenkov effect are studied. The formal usage of Cherenkov condition leads in this case to incorrect and unphysical results. The main task of this work was to find maximal radiation frequency and its dependence from the system parameters. This finite frequency was found. It was shown that at correct use of conservation laws the dependence of radiation and absorption frequencies on deviation from exact Cherenkov condition contains one discontinuity. The value of these frequencies on two sides of this discontinuity is different by 2.5 times. It was shown that the positions of these discontinuities depend on deviation value and corresponds to the condition of normal Doppler effect transformation into abnormal. Conditions that correspond to maximal radiation and absorption frequencies are different and are shifted in different directions form the exact Cherenkov condition (in relation to the velocity and dielectric permittivity).

MOPCH051	Operation of the First Undulator-based Femtoslicing Source	laser, electron, background, radiation	154
	S. Khan Uni HH, Hamburg K. Holldack, T. Kachel, T. Quast BESSY GmbH, Berlin R. Mitzner Universität Muenster, Physikalisches Institut, Muenster
	At the BESSY II storage ring, a source of sub-100-fs x-ray pulses with tunable polarization and excellent signal-to-background ratio has been constructed in 2004, based on laser-induced energy modulation ("femtoslicing") and subsequent angular separation of the short-pulse x-rays from an elliptical undulator. After commissioning and characterizing the source, short-pulse radiation is now routinely delivered for pump-probe applications. The paper summarizes the results from commissioning and operational experience as well as possible upgrade options. A. Zholents and M. Zoloterev, PRL 76 (1996), 912.

MOPCH057	The Design of a 1.8 keV Compton X-ray Generator for a SC RF Linac at KAERI	electron, laser, linac, brilliance	169
	A.V. Bondarenko, S.V. Miginsky BINP SB RAS, Novosibirsk Y.H. Han, Y.U. Jeong, B.C. Lee, S. H. Park KAERI, Daejon
	A quasi-monochromatic X-ray source based on the KAERI SC linac system has been designed and is being manufactured now. A 10 MeV 10 mA electron beam together with a 20 W 1.06 ?m laser beam will be used for 1.8 keV Compton X-ray generation with a few percentage of energy spread and 107 photons per second. A simple straight beamline was designed to deliver the electron beam with no degradation of its emittance and energy spread and to focus it to a proper size to produce the desired X-rays. We expect the first demonstration of 1.8 keV Compton X-ray generation in autumn 2006.

MOPCH062	Centroid, Size, and Emittance of a Slice in a Kicked Bunch	synchrotron, emittance, radiation, betatron	172
	C.-X. Wang, W. Guo ANL, Argonne, Illinois
	A transversely kicked bunch will decohere due to, among other things, chromatic and amplitude-dependent tune shifts. The chromatic tune shift leads to correlation between transverse and longitudinal phase space. Such a correlation can be used for compressing synchrotron radiation of the bunch with adequate optics. In this report, we revise the decoherence calculation to derive the centroid and second moments of a beam slice in a kicked bunch, taking into account chromatic and nonlinear decoherence, but neglecting wakefield and radiation damping, etc. A simple formula for estimating slice bunch length (and potential pulse compression ratio) is given for the ideal situation.

MOPLS072	Status of the HeLiCal Contribution to the Polarised Positron Source for the International Linear Collider	undulator, positron, electron, polarization	715
	J.A. Clarke, O.B. Malyshev, D.J. Scott CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire I.R. Bailey, P. Cooke, J.B. Dainton, L.I. Malysheva Liverpool University, Science Faculty, Liverpool D.P. Barber DESY, Hamburg E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, Y. Ivanyushenkov, J. Rochford CCLRC/RAL, Chilton, Didcot, Oxon G.A. Moortgat-Pick Durham University, Durham
	The baseline positron source for the International Linear Collider is a helical undulator-based design, which can generate unprecedented quantities of polarised positrons. A major thrust of the global design in this area is led by the UK-based HeLiCal collaboration. The collaboration takes responsibility for the design and prototyping of the helical undulator itself, which is a highly demanding short period device with very small aperture, and also leads the start to end simulations of the polarised particles to ensure that the high polarisation levels generated are maintained from the source, right through the beam transport systems and up to the interaction point itself. This paper will provide an update on the work of the collaboration, focusing on these two topic areas, and will also discuss future plans.

MOPLS076	The Stimulated Breit-Wheeler Process as a Source of Background e⁺e^- Pairs at the ILC	electron, background, resonance, electromagnetic-fields	727
	A.F. Hartin, A.F. Hartin OXFORDphysics, Oxford, Oxon
	Passage of beamstrahlung photons through the bunch fields at the interaction point of the ILC determines background pair production. The number of background pairs per bunch crossing due to the Breit-Wheeler, Bethe-Heitler and Landau-Lifshitz processes is well known. However the Breit-Wheeler process also takes place in and is modified by the bunch fields. A full QED calculation of this Stimulated Breit-Wheeler process reveals cross section resonances due to the virtual particle reaching the mass shell. The one loop Electron Self energy in the bunch field is also calculated and included as a radiative correction. The bunch field is considered to be a contant crossed electromagnetic field with associated bunch field photons. Resonance is found to occur whenever the energy of contributed bunch field photons is equal to the beamstrahlung photon energy. The Stimulated Breit-Wheeler cross section exceeds the ordinary Breit-Wheeler cross section by several orders of magnitude and a significantly different pair background may result.

MOPLS079	The Charged Beam Dumps for the International Linear Collider	linear-collider, collider, electron, TESLA	736
	R. Appleby UMAN, Manchester J.R.J. Bennett, T.A. Broome CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon C. Densham CCLRC/DL, Daresbury, Warrington, Cheshire H. Vincke CERN, Geneva
	The baseline configuration of the International Linear Collider requires 2 beam dumps per interaction region, each rated to 18MW of beam power, together with additional beam dumps for tuning purposes and machine protection. The baseline design uses high pressure moving water dumps, first developed for the SLC and used in the TESLA design, although a gas based dump is also being considered. In this paper we discuss the progress made by the international community on both physics and engineering studies for the beam dumps.

MOPLS080	A Laser-wire System at the ATF Extraction Line	laser, electron, extraction, optics	738
	S.T. Boogert, G.A. Blair, G.E. Boorman, A. Bosco, L. Deacon, C. Driouichi Royal Holloway, University of London, Surrey A. Aryshev, H. Hayano, V. Karataev, K. Kubo, N. Terunuma, J. Urakawa KEK, Ibaraki A. Brachmann, J.C. Frisch, M.C. Ross SLAC, Menlo Park, California N. Delerue JAI, Oxford S. Dixit, F.B. Foster, G.F. Gannaway, D.F. Howell, Q.M. Qureshi, A. Reichold, R. Senanayake OXFORDphysics, Oxford, Oxon L.J. Jenner Cockcroft Institute, Warrington, Cheshire T. Kamps BESSY GmbH, Berlin
	A new laser-wire system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.

MOPLS091	First Design of a Post Collision Line for CLIC at 3 TeV	CLIC, extraction, dipole, beam-losses	765
	V.G. Ziemann, T. J. C. Ekelof, A. Ferrari UU/ISV, Uppsala P. Eliasson CERN, Geneva
	As part of the Post collision diagnostic task of the ILPS work-package of EuroTeV we discuss a design of the beam line between the interaction point and the beam dump for CLIC with a center-of-mass energy of 3 TeV. The design is driven by the requirement to transport the beam and all secondaries such as beamstrahlung and coherent pairs to the beam dump with minimal losses. Moreover, we discuss the integration of novel diagnostic methods into the post collision beam line based on the detection of coherent pairs and monitoring the beam profile of the primary beam.

MOPLS118	Magnetic Modelling of a Short-period Superconducting Helical Undulator for the ILC Positron Source	undulator, positron, TESLA, cryogenics	840
	J. Rochford, E. Baynham, T.W. Bradshaw, F.S. Carr CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon I.R. Bailey, L.I. Malysheva Cockcroft Institute, Warrington, Cheshire D.P. Barber DESY, Hamburg A.J. Brummitt, Y. Ivanyushenkov CCLRC/RAL, Chilton, Didcot, Oxon J.A. Clarke, O.B. Malyshev, D.J. Scott CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire P. Cooke, J.B. Dainton Liverpool University, Science Faculty, Liverpool G.A. Moortgat-Pick Durham University, Durham
	A positron source utilising undulators is now defined as the baseline option for the International Linear Collider (ILC). The ILC requires a short period undulator, as close to 10mm as possible, that is capable of producing 10 MeV photons. The HeliCal collaboration in the UK has undertaken a programme to design, develop and produce a prototype undulator. As part of the programme, the group has used the OPERA software package to perform the magnetic design of the undulator. The design has addressed several issues, including the effect of magnetic material for the undulator former, optimal winding geometry, the magnetic flux inside the superconductor and its variation with undulator period and the winding bore. This paper summarizes the results of both the 2d and the 3d magnetic simulations.

MOPLS121	The DAFNE Beam Test Facility: from 1 to 10 Milliards of Particles	electron, linac, positron, target	846
	G. Mazzitelli, B. Buonomo, L. Quintieri INFN/LNF, Frascati (Roma) P. Valente INFN-Roma, Roma
	The DAFNE Beam Test Facility is operating since 2002, providing electrons, positrons and photons from the single particle up to 1010 particleS per spill and from 20 to 750 MeV. During these years, the facility has hosted tens of high energy test and experiments coming from all Europe, operating in a wide spread of multiplicity and energy. Operation performance and parameters, tools and diagnostics, as well as the main results obtained, are presented.

TUOAFI03	Production of MeV Photons by the Laser Compton Scattering Using a Far Infrared Laser at SPring-8	laser, FIR, electron, storage-ring	961
	H. Ohkuma, M. Shoji, S. Suzuki, K. Tamura, T. Yorita JASRI/SPring-8, Hyogo-ken Y. Arimoto Osaka University, Osaka M. Fujiwara, K. Kawase RCNP, Osaka K. Nakayama, S. Okajima Chubu University, Kasugai, Aichi
	In order to produce MeV gamma-ray by the Laser Compton scattering (LCS), a high power optically pumped Far Infrared (FIR) laser has been developed at SPring-8. In the case of the SPring-8 storage ring, the momentum acceptance is so large (± 200 MeV) that the scattered electron is re-accelerated, then the stored beam is not lost by the LCS process. The beam diagnostics beamline is used to inject a FIR laser beam against 8-GeV stored electron beam and to extract MeV gamma-ray produced by LCS. The FIR laser system, gamma-ray production system, and measured gamma-ray spectrum will be presented. Future plans will also be introduced. In order to produce higher intense gamma-ray, we are constructing new gamma-ray production system at another beamline.
	Transparencies

TUYFI01	Gantry Design for Proton and Carbon Hadrontherapy Facilities	proton, ion, dipole, GSI	964
	U. Weinrich GSI, Darmstadt
	Using an isocentric gantry improves the efficiency and the flexibility of cancer treatments with ion beams (hadrontherapy). After an overview of the constraints imposed to these heavy equipments the gantries constructed for both proton and carbon ion facilities will be described. Finally, the new studies undertaken to decrease the cost of such equipments will presented.
	Transparencies

TUPCH010	Profile Measurement by Beam Induced Fluorescence for 60 MeV/u to 750 MeV/u Heavy Ion Beams	ion, background, vacuum, heavy-ion	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.

TUPCH032	Precise Measurements of the Vertical Beam Size in the ANKA Storage Ring with an In-air X-ray Detector	resonance, synchrotron, electron, radiation	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.

TUPCH050	Beam Profile Measurements with the 2-D Laser-wire	laser, electron, PETRA, injection	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.

TUPCH071	Testing the Silicon Photomultiplier for Ionization Profile Monitor	IPM, synchrotron, CERN, MCP	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.

TUPCH074	Fast and Precise Beam Energy Monitor Based on the Compton Backscattering at the VEPP-4M Collider	electron, laser, collider, scattering	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.

TUPCH083	Time-resolved Spectrometry on the CLIC Test Facility 3	electron, radiation, linac, synchrotron	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.

TUPCH096	High-intensity Bremsstrahlung Monitoring System for Photonuclear Technologies	electron, radiation, simulation, target	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.

TUPCH106	Commissioning the SPEAR3 Diagnostic Beamlines	single-bunch, diagnostics, optics, coupling	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.

TUPCH179	R&D on Copper Beam Ducts with Antechambers and Related Vacuum Components	KEKB, electron, wiggler, vacuum	1438
	Y. Suetsugu, H. Hisamatsu, K.-I. Kanazawa, K. Shibata, M. Shimamoto, M. Shirai KEK, Ibaraki
	A beam duct with antechambers is able to reduce the effect of photoelectrons and, as a result, to suppress the electron cloud effect of positron or proton beam. It will be adopted for a future high current positron/proton rings and also a damping ring of a linear collider. Copper beam ducts with one or two antechambers were manufactured for test and the feasibility was studied. The test chambers were then installed into the KEK B-factory positron ring and the performance was investigated with a beam current up to 2000 mA. The temperature, the pressure and the electron density in the beam channel were measured during the beam operation. The photoelectron, for example, was found to be well suppressed as expected compared to that of a simple circular beam duct. The related vacuum components, such as a connection flange, a bellows chamber and a gate valve with the same cross section to the beam duct, were also developed and tested together with the beam duct.

WEOAPA03	MICE Overview - Physics Goals and Prospects	emittance, focusing, scattering, radiation	1870
	M. Yoshida Osaka University, Osaka
	Ionization cooling, a technique in which muon beam is passed through a series of absorbers and followed by RF-acceleration, is a proposed method for cooling muon beam, i.e., phase-space reduction. The international Muon Ionisation Cooling Experiment (MICE), which will construct and operate a realistic cooling channel and measure the beam cooling performance, is the first essential step towardsrealization of nutrino factories and eventually muon colliders based on intense muon sources. The MICE have got approved to be constructedin Rutherford Appleton Laboratory (RAL) and the fist beam commissioning is scheduled in 2007. The physics goal and future prospects of the MICE together with the beamline and the instruments which is now being built will be described.
	Transparencies

WEPCH143	Electron Linac Based e,X-radiation Facility	target, electron, radiation, simulation	2257
	V.I. Nikiforov, A. Dovbnya, N.A. Dovbnya, V.L. Uvarov NSC/KIPT, Kharkov
	In a number of technologies based on high-current electron accelerators bremsstrahlung is generated in the interaction of the beam with the irradiated object. Thus, in addition to the electron radiation, the bremsstahlung may be used for carring out of different technolodgical programs (e,X-facility). A method for the numerical analysis and optimization of the radiation characteristics of such installation is proposed. The accelerator beam track, starting from the electron source and up to output devices is considered as a single multicomponent target consisting of the layers of different materials. The thickness of each layer is measured in the generalized units of the "stopping length". Using the method of simulation based on the PENELOPE/2001 system the characteristics of the mixed e,gamma-radiation field (energy yield of electrons, photons and their ratio) as function of the stopping length for actual or anticipated version of output equipment can be calculated. To illustrate the method, the parameters of the beam path of the NSC KIPT Linacs used as e,X-facilities was analyzed.

WEPCH166	Beam Test of Thermionic Cathode X-band RF-gun and Linac for Monochromatic Hard X-ray Source	laser, electron, linac, cathode	2319
	K. Dobashi, A. Fukasawa, M. D. Meng, T. Natsui, F. Sakamoto, M. Uesaka, T. Yamamoto UTNL, Ibaraki M. Akemoto, H. Hayano, T. Higo, J. Urakawa KEK, Ibaraki
	A compact hard X-ray source based on laser-electron collision is proposed. The X-band linac is introduced to realize a very compact system. 2MeV electron beam with average current 2μampere at 10 pps, 200 ns of RF pulse is generated by a thermionic cathode X-band RF-gun. Beam acceleration and X-ray generation experiment by the X-band beam line are under way.

WEPLS021	The PLASMONX Project for Advanced Beam Physics Experiments	laser, electron, vacuum, emittance	2439
	L. Serafini, A. Bacci, R. Bonifacio, M. Cola, C. Maroli, V. Petrillo, N. Piovella, R. Pozzoli, M. Rome, A.R. Rossi, L. Volpe INFN-Milano, Milano D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, F. Broggi, C. De Martinis, D. Giove, M. Mauri INFN/LASA, Segrate (MI) W. Baldeschi, A. Barbini, M. Galimberti, A. Giulietti, A. Gizzi, P. Koester, L. Labate, S. Laville, A. Rossi, P. Tomassini CNR/IPP, Pisa U. Bottigli, B. Golosio, P.N. Oliva, A. Poggiu, S. Stumbo INFN-Cagliari, Monserrato (Cagliari) C.A. Cecchetti, D. Giulietti UNIPI, Pisa D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca Università di Roma I La Sapienza, Roma P. Musumeci INFN-Roma, Roma
	The Project PLASMONX is well progressing into its design phase and has entered as well its second phase of procurements for main components. The project foresees the installation at LNF of a Ti:Sa laser system (peak power > 170 TW), synchronized to the high brightness electron beam produced by the SPARC photo-injector. The advancement of the procurement of such a laser system is reported, as well as the construction plans of a new building at LNF to host a dedicated laboratory for high intensity photon beam experiments (High Intensity Laser Laboratory). Several experiments are foreseen using this complex facility, mainly in the high gradient plasma acceleration field and in the field of mono-chromatic ultra-fast X-ray pulse generation via Thomson back-scattering. We present an innovative scheme of external injection of the SPARC beam into laser wake-field driven plasma waves. Detailed numerical simulations have been carried out to study the generation of short electron bunches, to be injected into plasma waves driven with adiabatically variable density in order to compress the bunch at injection and further accelerate it by preserving a small energy spread and good beam quality.

WEPLS022	ILC Beam Energy Measurement based on Synchrotron Radiation from a Magnetic Spectrometer	radiation, electron, synchrotron, synchrotron-radiation	2442
	E. Syresin, B.Zh. Zalikhanov JINR, Dubna, Moscow Region K.H. Hiller, H.J. Schriber DESY Zeuthen, Zeuthen R.S. Makarov MSU, Moscow
	The magnetic spectrometer with a relative energy resolution of 5·10^-5 was proposed for ILC beam energy measurements. The beam energy measurement is based on precise definition of the beam position at a resolution of 100 nm and B-field integral at an accuracy of 2E-5. A complementary method of the beam energy measurement is proposed at registration of synchrotron radiation (SR) from the energy spectrometer dipole magnets. The measurements of both edge horizontal positions for SR fan on a distance of 50-70 m downstream of the spectrometer magnets permit to determine the beam energy with required resolution. The main principles of the beam energy measurements based on SR, the numerical simulations of SR performed by the GEANT code and proposal of SR monitors with submicron resolution are discussed.

WEPLS045	Study on Low-energy Positron Polarimetry	positron, electron, target, scattering	2475
	A. Schaelicke, K. Laihem, S. Riemann, A. Ushakov DESY Zeuthen, Zeuthen R. Dollan, Th. Lohse Humboldt University Berlin, Institut für Physik, Berlin
	For the design of the International Linear Collider (ILC) a polarised positron source based on a helical undulator system has been proposed. In order to optimise the positron beam, i.e., to ensure high intensity as well as high degree of polarisation, a measurement of the polarisation close to the positron creation point is envisaged. In this contribution methods to determine the positron polarisation at low energies are investigated. These studies are based on simulations with an extended version of Geant4, which allows the tracking of polarised particles taking into account the spin effects.

WEPLS046	Radiation Levels and Activation at the ILC Positron Source	positron, target, undulator, electron	2478
	A. Ushakov, S. Riemann DESY Zeuthen, Zeuthen Eckhard. Elsen, K. Floettmann DESY, Hamburg K.N. Sanosyan CANDLE, Yerevan
	An undulator-based positron source is recommended as baseline design for the International Linear Collider (ILC). Photons generated by electrons passing an undulator hit a rotating target and create electron-positron pairs. The positrons are captured and accelerated. An advantage of this source is the significantly lower radiation level in comparison to a conventional positron source which uses the electron beam directly to produce electron-positron pairs. The fluxes of neutrons and photons have been calculated with the particle transport code FLUKA. The activation of the positron source components has been estimated depending on the parameters of the source. The results for undulator-based and conventional positron sources are compared and presented.

WEPLS048	Development of a Positron Production Target for the ILC Positron Source	target, positron, vacuum, undulator	2484
	I.R. Bailey, I.R. Bailey, J.B. Dainton, D.J. Scott Cockcroft Institute, Warrington, Cheshire V. Bharadwaj, J. Sheppard SLAC, Menlo Park, California P. Cooke, P. Sutcliffe Liverpool University, Science Faculty, Liverpool J.G. Gronberg, D.J. Mayhall, W.T. Piggott, W. Stein LLNL, Livermore, California
	The future International Linear Collider (ILC) will require of order 10¹⁴ positrons per second to fulfil its luminosity requirements. The current baseline design produces this unprecedented flux of positrons using an undulator-based source. In this concept, a collimated beam of 10MeV photons produced from the action of an undulator on the main electron beam of the ILC is incident on a conversion target. Positrons produced in the resulting electromagnetic shower can then be captured, accelerated and injected into a damping ring. The international community is pursuing several alternative technologies to develop a target capable of long-term operation in the intense photon beam. In the design being developed jointly by the Cockcroft Institute, LLNL and SLAC, a thin (0.4 radiation length) water-cooled Titanium alloy target wheel of diameter 4m is rotated at approximately 1000rpm to spread the incident power of each pulse over a wide area. We present the latest target design, report on the status of the target prototypes and computer models, and review the interplay between the target technology, capture optics, photon collimator and remote-handling systems.

WEPLS060	CLIC Polarized Positron Source Based on Laser Compton Scattering	laser, CLIC, positron, damping	2520
	F. Zimmermann, H.-H. Braun, M. Korostelev, L. Rinolfi, D. Schulte CERN, Geneva S. Araki, Y. Higashi, Y. Honda, Y. Kurihara, M. Kuriki, T. Okugi, T. Omori, T. Taniguchi, N. Terunuma, J. Urakawa KEK, Ibaraki X. Artru, R. Chehab, M. Chevallier IN2P3 IPNL, Villeurbanne E.V. Bulyak, P. Gladkikh NSC/KIPT, Kharkov M.K. Fukuda, K. Hirano, M. Takano NIRS, Chiba-shi J. Gao IHEP Beijing, Beijing S. Guiducci, P. Raimondi INFN/LNF, Frascati (Roma) T. Hirose, K. Sakaue, M. Washio RISE, Tokyo K. Moenig DESY Zeuthen, Zeuthen H.D. Sato HU/AdSM, Higashi-Hiroshima V. Soskov LPI, Moscow V.M. Strakhovenko BINP SB RAS, Novosibirsk T. Takahashi Hiroshima University, Higashi-Hiroshima A. Tsunemi SHI, Tokyo V. Variola, Z.F. Zomer LAL, Orsay
	We describe the possible layout and parameters of a polarized positron source for CLIC, where the positrons are produced from polarized gamma rays created by Compton scattering of a 1.3-GeV electron beam off a YAG laser. This scheme is very energy effective using high finesse laser cavities in conjunction with an electron storage ring. We point out the differences with respect to a similar system proposed for the ILC.

THPCH127	Development of MATLAB-based Data Logging System at Siam Photon Source	controls, storage-ring, synchrotron, SPS	3098
	P. Klysubun, C. Netsai NSRC, Nakhon Ratchasima
	New data logging and retrieval systems are currently under development at Siam Photon Source. The systems are written entirely with MATLAB language and utilize two MATLAB toolboxes to handle data communications. The two toolboxes are Open Process Control Toolbox, which is used to carry out communications with Programmable Logic Controllers (PLCs) via Open Process Control Data Access (OPCDA), and Data Acquisition Toolbox, which handles communications with other systems via RS-232 and IEEE-488 interconnections. The interface with the database is handled by the MATLAB Database Toolbox. These MATLAB-based logging and retrieval systems enable accelerator physicists to easily import the logged data to accelerator modeling tools for studies of the accelerator optics. Beamline researchers and users can also write their own retrieval programs to access only the data they need. In this paper we describe the concept, the current status of the systems, and the planned improvements to be carried out in the future.

THPCH154	Development of Pulsed Laser Super-cavity for Compact High Flux X-ray Sources	laser, electron, storage-ring, target	3155
	K. Sakaue, M. Washio RISE, Tokyo S. Araki, Y. Higashi, Y. Honda, T. Taniguchi, J. Urakawa KEK, Ibaraki M.K. Fukuda, M. Takano NIRS, Chiba-shi H. Sakai ISSP/SRL, Chiba N. Sasao Kyoto University, Kyoto
	Pulsed-laser super-cavity is being developed at KEK-ATF for the application of a compact high brightness x-ray source based on Laser Compton Scattering. We use a Fabry-Perot optical cavity with a pulsed laser. The cavity increases a laser effective power, and at the same time, stably makes a small laser spot in side the cavity. In addition, the pulsed-laser gives much higher peak power. Thus, this scheme will open up a new possibility for building a compact high-brightness x-ray source, when collided with an intense bunched electron beam. We are now planning to build such an x-ray source with a 50MeV multi-bunch linac and a 42cm Fabry-Perot cavity using pulse stacking technology. We actually finished construction of the 50MeV linac and will start its operation in the spring, 2006. Development of the pulsed-laser super-cavity and future plan of our compact x-ray source will be presented at the conference.

THPCH158	A Phased-locked S.A.M. Mode-locked Laser for the ELSA Photoinjector	laser, ELSA, electron, linac	3164
	V. Le Flanchec, P. Balleyguier CEA, Bruyères-le-Châtel
	A new laser oscillator has been developed for the ELSA photoinjector. It is a fibered-diode-pumped mode-locked Nd:YVO4 laser, with a completely passive cooling design. Mode-locking is achieved by a saturable absorber mirror. Such a passive laser oscillator must be synchronized with the ELSA electron bunches. A phased-locked loop has been developed for that purpose. We present the main design aspects resulting from the high stability requirement of ELSA. The first electron spectra measurements show the high level of energy stability achieved. We also present improvements in the laser injection system leading to a higher transverse stability, a more uniform cathode illumination, and a better transmission of the whole system.

THPLS019	The Metrology Light Source: an Electron Storage Ring Dedicated to Metrology	electron, radiation, storage-ring, synchrotron	3314
	R. Klein, G. Ulm PTB, Berlin P. Budz, K. Buerkmann-Gehrlein, J. Rahn, G. Wuestefeld BESSY GmbH, Berlin
	PTB, the German National Metrology Institute, in close cooperation with BESSY, is currently setting up a low-energy electron storage ring (200 MeV up to 600 MeV electron energy), the Metrology Light Source MLS, which will be dedicated to metrology and technology development in the UV and EUV spectral range which synchrotron radiation. The MLS has been designed by BESSY according to PTB specifications. User operation is scheduled to begin in 2008. Currently, the building, housing the storage ring, is nearly completed, and all major parts of the storage ring and the injection system have been ordered or have already been delivered. The MLS will be equipped with all the instrumentation necessary to measure the storage ring parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty, enabling PTB to operate the MLS as a primary source standard. Moreover, calculations show, that the MLS is ideally suited for the production of coherent synchrotron radiation in the far IR and THz region. We give a status update on the construction, the instrumentation for the measurement of the storage ring parameters and calculations for a low-

THPLS025	Diamond Light Source Vacuum Systems Commissioning Status	vacuum, storage-ring, controls, DIAMOND	3332
	M.P. Cox, B. Boussier, S. Bryan, B.F. Macdonald, H.S. Shiers Diamond, Oxfordshire
	Diamond Light Source is a new 3 GeV light source currently being commissioned in the UK. The main vacuum systems are a 561.6 m circumference electron storage ring and a 158.4 m circumference booster ring. The storage ring target operating pressure is 1·10^-9 mbar with 300 mA of stored beam after 100 A.h of beam conditioning. The booster ring target operating pressure is up to an order of a magnitude higher. Pumping is provided by discrete noble diode ion pumps, supplemented by titanium sublimation pumps and NEG cartridge pumps. Vacuum vessel construction is mainly from 316LN stainless steel. There is no in situ bakeout except for the 24 storage ring straights and the front ends. An ex situ bakeout process is used for the storage ring arcs followed by installation under vacuum. This paper reports results and experience from the construction and commissioning of the diamond vacuum systems.

THPLS036	Results of the Straight-sections Upgrade of the Photon Factory Storage Ring	undulator, vacuum, storage-ring, factory	3365
	T. Honda, S. Asaoka, W.X. Cheng, K. Haga, K. Harada, Y. Hori, M. Izawa, T. Kasuga, Y. Kobayashi, H. Maezawa, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. Nogami, T. Obina, C.O. Pak, S. Sakanaka, H. Sasaki, Y. Sato, T. Shioya, M. Tadano, T. Takahashi, Y. Tanimoto, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto KEK, Ibaraki
	At the 2.5-GeV ring of the Photon Factory (PF), a large reconstruction of the lattice around the straight sections* has been accomplished in 2005. As a result, four short straight sections of 1.5 m have been newly created, and the lengths of the existing straight sections have been much improved. For example, the length of the longest straight section has been extended to 9 m from 5 m. The optics has been optimized for installing short-period narrow-gap (in-vacuum) undulators at the new straight sections. The reconstruction work on the ring was held from March to September 2005. In the range over two-thirds of the storage ring, all the quadrupole magnets and all the beam ducts have been renewed and rearranged. Commissioning of the storage ring was started from the end of September 2005 and continued for one month. The operation for the user experiment was resumed from the end of October on schedule. Though we made no in-situ baking after the installation for the beam ducts, the vacuum scrubbing by the synchrotron radiation is running very well. The product of the beam lifetime and the beam current exceeded 700 A min for the operation current 450 mA at the end of December 2005. *S. Asaoka et al. "New Upgrade Project for the Photon Factory Storage Ring", AIP Conf. Proc. 705, p161 (2004).

THPLS039	Upgrade and Current Status of the PF Ring Vacuum System	vacuum, insertion, controls, insertion-device	3371
	Y. Tanimoto, Y. Hori, T. Nogami, T. Uchiyama KEK, Ibaraki
	The vacuum system for the KEK Photon Factory (PF) was extensively modified in 2005 as part of the PF ring straight-sections upgrade project. This project required replacements of the quad magnets in both northern and southern straight-sections that account for nearly two-thirds of the whole circumference. Therefore, the vacuum ducts in these new quad magnets (Q-ducts), as well as the vacuum ducts in their related bend magnets (B-ducts), needed to be replaced. The new Q-ducts have a narrower cross-section and are equipped with new 4-electrode beam position monitors, and the new B-ducts are furnished with new distributed ion pumps. After the installation of these vacuum chambers, we omitted the thermal in-situ baking, anticipating that beam scrubbing would provide more efficient cleaning. Furthermore, even pre-baking before installation was not performed for the chambers in the northern half in order to evaluate the effect of the pre-baking during the early period of the commissioning. Details of these modifications, as well as the current status of the new vacuum system, will be presented.

THPLS044	Preliminary Experiment of the Thomson Scattering X-ray Source at Tsinghua University	laser, electron, scattering, linac	3386
	Y.-C. Du, Cheng. Cheng. Cheng, Q. Du, Du.Taibin. Du, W.-H. Huang, Y. Lin, C.-X. Tang, S. Zheng TUB, Beijing
	A preliminary experiment of the Thomson scattering x-ray source is being planned and constructed to generate short-pulsed, tunable x-rays in the range of ~4.5 kev by Thomson scattering of laser photons from a relativistic electron beam. Laser photons of ? = 1064 nm are Thomson backscattered by a 16MeV electron beam from a 16MeV Backward Travelling Wave (BTW) electron linac. The laser is derived from a 2J,10ns Nd:YAG laser. The parameters of electron beam and laser have been measured. The simulated and experiment results are described in this paper.

THPLS052	The Vacuum System for the Spanish Synchrotron Light Source (ALBA)	vacuum, storage-ring, dipole, synchrotron	3398
	E. Al-Dmour, D. Einfeld, M. Q. Quispe, L. Ribó ALBA, Bellaterra
	ALBA will be a 3GeV, third generation synchrotron light facility to be built near Barcelona (Spain). The design phase of ALBA is almost completed and the main components have been ordered, which includes the vacuum chambers for the storage ring. Commissioning of the storage ring is foreseen to start at the end of 2008. The circumference of the storage ring of ALBA is 268.8 m, and it will be divided into 16 vacuum sections by ultra high vacuum (UHV) gate valves. The vacuum chamber will be made of stainless steel with an internal vertical aperture of 28 mm and 72 mm width. The vacuum chamber will be connected to an antechamber with a slot of 10 mm height and 20 mm width. The antechamber will have the discrete absorbers, which will absorb the unwanted synchrotron radiation. The pumping will be by sputter ion pumps (SIP) and NEG pumps, with an overall pumping speed from SIP of 57400 l/s. This will maintain an average dynamic pressure of around 1.0·10^-9 mbar to achieve a beam lifetime > 15 hours at the designed current. No in-situ bakeout is foreseen, as the vacuum section will be conditioned ex-situ and installed under vacuum to the storage ring.

THPLS064	Design Concept of the Vacuum System for the 3 GeV Taiwan Photon Source	vacuum, simulation, electron, storage-ring	3433
	G.-Y. Hsiung, C.K. Chan, C.-H. Chang, H.P. Hsueh, T.L. Yang NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	The design concept of the vacuum system for the electron storage ring of the Taiwan Photon Source (TPS), 518.4 m in circumference, is described. The vacuum system for the synchrotron light source not only meets the specifications of an electron beam energy of 3 GeV and a beam current at 400 mA but also provides a safety factor of 1.7 (~ 500 mA) at 3.3 GeV at the upper bound. The vacuum system for the storage ring is built with consideration of the following features: (1) Large aluminum bending chambers to simplify the ultra-high vacuum (UHV) structure; (2) Absorbers located as far from the source as possible to reduce the heat load and associated yield of photon stimulated desorption (PSD) as well as the photoelectron; (3) Vacuum pumps located in the antechamber and closed to the absorbers to increase the localized pumping efficiency and to minimize the impedance of beam ducts; (4) Quantity of flanges and bellows is significantly reduced. Configuration of the pumps, results of the simulation for the pressure and thermal stress, and the criteria of the design will be discussed.

THPLS065	Optimization for Taiwan Photon Source Electron Beam Position Monitors through Numerical Simulation	simulation, electron, synchrotron, synchrotron-radiation	3436
	H.P. Hsueh, C.-H. Chang, G.-Y. Hsiung, C.-K. Kuan, T.-S. Ueng NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	One of the key steps toward successfully building the newly proposed 3rd generation synchrotron radiation research facility, Taiwan Photon Source (TPS), is to optimize the design of the high resolution electron beam position monitors through numerical simulation. With more advanced electromagnetic simulation tool like MAFIA tailored specifically for particle accelerator, the design for the high resolution electron beam position monitors can be tested in such environment before actually fabricated and physically tested. The design goal of our high resolution electron beam position monitors is to achieve 0.1 micron resolution if allowed by engineering limitations. The design consideration to achieve this 0.1 micron resolution goal will also be discussed. The first design has been carried out and the correlated simulations were also carried out with MAFIA. The results are presented and discussed here. Sensitivity as high as 200 has been achieved at 500 MHz. Further study will also be described.

THPLS079	Bunch Diffusion Measurements at the Advanced Light Source	storage-ring, injection, electron, lattice	3466
	F. Sannibale, W.E. Byrne, C.-W. Chiu, J. Guo LBNL, Berkeley, California J.S. Hull, O.H.W. Siegmund, A.S. Tremsin, J. Vallerga UCB, Berkeley, California
	In storage ring based synchrotron light sources, a long beam lifetime is usually a fundamental requirement for a high integrated brightness. The dynamic aperture and the momentum acceptance of lattices are carefully studied and maximized as much as possible for a long lifetime performance. On the other hand, large momentum acceptance and dynamic aperture increase the probability that a particle diffuses from one bunch to another. Diffusion can represent a severe limitation for those experiments where the samples have long relaxation times requiring empty buckets between bunches. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory we have characterized the particle diffusion for the present lattice in order to evaluate its impact on a special user operation dedicated to these long relaxation time experiments and on the incoming top-off injection mode for the ALS.

THPLS111	Beam Loading Measurement and its Application to the Harmonic RF Control of the APS PAR	beam-loading, synchrotron, injection, controls	3538
	C. Yao, E.E. Cherbak, N.P. Di Monte, A. Grelick, T. Smith, B.X. Yang ANL, Argonne, Illinois
	The particle accumulator ring (PAR) has dual rf systems: a CW mode fundamental rf system (RF1) operating at 9.77 MHz that accumulates multiple linac pulses into a 0.8-ns bunch, and a 12th harmonic rf (RF12) that compresses the bunch length further to 0.34 ns for injection into the booster. The RF12 capture process is critical for optimal performance of the PAR. We investigated the effects of beam loading during the RF12 capture and bunch length compression process with both spectrum analysis and streak camera imaging. Based on these observations, a new timing scheme for the RF12 tuner and power control was implemented, which has substantially improved the performance of the PAR. We report our observation, the new timing scheme, and beam parameters after optimization.

THPLS125	A Concept on Electric Field Error Compensation for the ANKA Superconductive Undulator	undulator, electron, permanent-magnet, simulation	3577
	D. Wollmann, T. Baumbach, A. Bernhard University of Karlsruhe, Karlsruhe S. Casalbuoni, MH. Hagelstein, B.K. Kostka, R. Rossmanith FZK, Karlsruhe G. Gerlach University of Dresden, Institute for Solid-State Electronics, Dresden F. Schoeck, E. Steffens, M. Weisser University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
	In April 2005 a superconductive undulator test device, the so-called SCU14 (period length 14 mm, 100 periods) was installed at ANKA. Before installation, the magnetic field was measured and documented. This was the first test of a superconductive undulator in a storage ring and the dominating questions to be answered were related to the interaction of the undulator with the beam. The field quality was of lower importance and will be improved by a modified mechanical fabrication technique at the next superconductive undulators. Nevertheless, after finishing the fundamental beam tests the question was discussed how one would improve the field quality (minimize the phase error) of the existing undulator by local correction devices. The concepts could be used later in a weaker form for local field corrections at future undulators, if necessary.

THPLS130	Thermal Neutron Demagnetization of NdFeB Magnets	electron, vacuum, ion, undulator	3589
	R.W. Klaffky DOE/OFES, Germantown, Maryland R.M. Lindstrom NIST, Gaithersburg, Maryland B. Maranville, R. Shull National Institute of Standards and Technology, Gaithersburg, Maryland B.J. Micklich, J.H. Vacca ANL, Argonne, Illinois
	At the Advanced Photon Source at Argonne National Laboratory, NdFeB insertion device magnets have shown losses of magnetization on a few straight sections where the largest electron beam losses occur due to limiting vacuum chamber apertures. In the worst case, these magnetization losses were evident after a three month operational period. To isolate the effect that thermal neutrons have on these magnets, the magnetization and coercivity were studied for two NdFeB grades as a function of dose from 7.5 x 10(12) to 6 x 10(13) neutrons/cm2. After saturation, the remanent magnetization was found to decrease linearly with the logarithm of the dose. At a dose of 7.5 x 10(12) neutrons/cm2.sec, there was already a 43 percent magnetization loss for the N45 grade and a 15 percent loss for the N48 grade. There was no apparent change in coercivity with dose. The change in remanent magnetization is a consequence of boron thermal neutron capture through the 10B(n,alpha)7Li reaction, which generates MeV energy alpha particles and lithium ions.