IPAC2013 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOYCB101	Brightness and Coherence of Synchrotron Radiation and FELs	brightness, FEL, electron, undulator	16
	Z. Huang SLAC, Menlo Park, California, USA
	Essential properties of radiation from storage rings and FELs include spatial- and temporal beam brightness and coherence. Starting from a fundamental representation of the electron beam as a radiating source the electromagnetic power can be represented as modes in phase-space to characterize beam quality. For storage rings, conditions for transverse coherence are possible which can lead to high-resolution imaging under a variety of polarization conditions. For FELs the radiation brightness is over 10 orders of magnitude higher with finite temporal coherence times and much of the total FEL power contained in the dominant mode. This presentation should provide an overview of the above.
	Slides MOYCB101 [9.731 MB]

MOZB102	Undulator Technologies for Future Free Electron Laser Facilities and Storage Rings	undulator, vacuum, electron, wiggler	26
	M.-E. Couprie SOLEIL, Gif-sur-Yvette, France
	Insertion devices (undulators and wigglers) are key components for high brightness third generation synchrotron sources and for the amplifying medium of free electron lasers. Different technological developments carried out worldwide lead to improved undulator performance. In particular, the advances concerning the in vacuum permanent magnet systems, in particular for short period ones with the operation at cryogenic temperature with NdFeB or PrFeB magnets or for long period ones where in vacuum wigglers will be described. Secondly, progress in Elliptical Polarised Undulators (EPU) will be discussed, such as the DELTA undulator. Recent progress in superconducting undulators will also be reported. Finally, the effect of the insertion devices on the light source operation is analysed, either with the strategies to compensate unwanted effects or in viewing taking advantage of them as for Robinson or damping wigglers for reducing storage ring horizontal emittance.
	Slides MOZB102 [8.940 MB]

MOZB202	The First Long Shutdown (LS1) for the LHC	dipole, ion, luminosity, vacuum	44
	F. Bordry, S. Baird, K. Foraz, A.-L. Perrot, R.I. Saban, J.Ph. G. L. Tock CERN, Geneva, Switzerland
	The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections so as to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. LS1 will see a massive programme of maintenance for the LHC and its injectors in the wake of more than three years of operation without the long winter shutdowns that were the norm in the past. The main driving effort will be the consolidation of the 10,170 high-current splices between the superconducting magnets. The presentation describes first the preparation phase with the prioritisation of the activities, the building of the teams and the detailed planning of the operation. Then, it gives the status after 3 months and the restart plans for all CERN accelerators. First lessons learnt for the 2nd long shutdown (LS2) will conclude the presentation.
	Slides MOZB202 [13.675 MB]

MOPEA010	Transfer of RIB’s between ISOL Target and Experiment Hall at SPIRAL 2	target, ion, remote-handling, ISOL	85
	F.R. Osswald, T. Adam, E. Bouquerel, D. Boutin, A. Dinkov, M. Rousseau, A. Sellam IPHC, Strasbourg Cedex 2, France N.Yu. Kazarinov JINR, Dubna, Moscow Region, Russia H. Weick, M. Winkler GSI, Darmstadt, Germany
	Funding: The authors would like to acknowledge the German-French and Russian-French agreements enabling the allocation of resources : IN2P3 - GSI (id. 12-69), and IN2P3 - JINR (id. 11-88) collaborations. The production of intense radioactive beams requires a high power target, an efficient beam selection and transport, safe operations and a reliable-cost effective facility. The SPIRAL 2 project a so called second generation RIB facility is under construction at GANIL. The low energy RIB’s will be produced by neutron induced fissions obtained from a 40 MeV primary beam (deutons) and a graphit convertor. Several issues must be addressed in order to insure the safety rules and ultimately the performances requested by the scientific programme. Among them, the space charge dominated regime during the extraction of the beam after the target and the ion source, the compromise between beam transmission, rejection of the light-ion beam, and management of the main safety features. Most of the investigations currently in progress are devoted to the nuclear engineering, the maintenance and the multi-scale integration of the segmented beam line with the infrastructure. * RIB dynamics of the SPIRAL 2 Transfer Line, HIAT 2012 Simulation of Hollow Beam formation at SPIRAL 2, IPAC 2011 * A Secondary Radioactive Beam Line Section for SPIRAL 2, HIAT 2009

MOPEA014	Temporal and Spectral Observation of Laser-induced THz Radiation at DELTA	electron, laser, storage-ring, simulation	94
	P. Ungelenk, H. Huck, M. Huck, M. Höner, S. Khan, R. Molo, A. Schick DELTA, Dortmund, Germany N. Hiller, V. Judin KIT, Karlsruhe, Germany
	Funding: Work supported by the DFG, the BMBF, the Federal State NRW, the Initiative and Networking Fund of the Helmholtz Association, and the German Federal Ministry of Education and Research. Coherent THz pulses caused by a laser-induced density modulation of the electron bunches are routinely produced and observed at DELTA, a 1.5 GeV synchrotron light source operated by the TU Dortmund University. New measurements performed with a fast hot-electron bolometer allow insight into the turn-by-turn evolution of these pulses. Furthermore, first results from a Fourier transform infrared spectrometer, which is currently under commissioning, are presented.

MOPEA019	Studies of Bunch-bunch Interactions in the ANKA Storage Ring with Coherent Synchrotron Radiation using an Ultra-fast Terahertz Detection System	synchrotron, storage-ring, wakefield, synchrotron-radiation	109
	A.-S. Müller, B.M. Balzer, C.M. Caselle, N. Hiller, M. Hofherr, K.S. Ilin, V. Judin, B. Kehrer, S. Marsching, S. Naknaimueang, M.J. Nasse, J. Raasch, A. Scheuring, M. Schuh, M. Schwarz, M. Siegel, N.J. Smale, J.L. Steinmann, P. Thoma, M. Weber, S. Wuensch KIT, Karlsruhe, Germany
	Funding: Supported by Initiative and Networking Fund of the Helmholtz Association under contract No. VH-NG-320 and German Federal Ministry of Education and Research under Grant. Noss. 05K10VKC and 05K2010VKD In the low-alpha operation mode of the ANKA synchrotron light source, coherent synchrotron radiation (CSR) is emitted from short electron bunches. Depending on the bunch current, the radiation shows bursts of high intensity. These bursts of high intensity THz radiation display a time evolution which can be observed only on long time scales with respect to the revolution period. In addition, long range wake fields can introduce a correlation between the bunches within a bunch train and thus modify the observed behavior. A novel detection system consisting of an ultra-fast superconducting THz detector and data acquisition system was used to investigate correlations visible on the bursting pattern and to study the interactions of very short pulses in the ANKA storage ring.

MOPEA020	Comparison of Different Approaches to Determine the Bursting Threshold at ANKA	synchrotron, storage-ring, electron, synchrotron-radiation	112
	P. Schönfeldt, N. Hiller, V. Judin, A.-S. Müller, M. Schwarz, J.L. Steinmann KIT, Karlsruhe, Germany
	The synchrotron light source ANKA at the Karlsruhe Institute of Technology provides a dedicated low-α-optics. In this mode bursting of Coherent Synchrotron Radiation (CSR) is observed for bunch charges above a threshold that depends on beam parameters. This threshold can be determined by several approaches, e.g. bunch lengthening or changes in the THz radiation spectra. This paper compares different methods and their implementation at the ANKA storage ring outlining their advantages, disadvantages and limitations, including reliability and possibility of real time analysis.

MOPEA024	Effects of Insertion Devices in the High Field Lattice Structure of ILSF Storage Ring	dynamic-aperture, insertion, insertion-device, quadrupole	124
	F. Saeidi, E. Ahmadi, H. Ghasem ILSF, Tehran, Iran H. Ghasem IPM, Tehran, Iran
	We have studied effects of different insertion devices(IDs) in the high filed ILSF storage ring. Radiation from the IDs leads to change emittance and energy spread of the ring and magnetic field of them results to beta-beating, tune shift and shrink of dynamic aperture. This paper describes effects of the IDs on beam parameters of the high field lattice structure of ILSF storage ring and proposes the compensation method of these effects. farhad.saeidi@ipm.ir

MOPEA038	Coherent Wiggler Radiation of Picosecond CW Electron Beam Produced by DC-SRF Photoinjector	wiggler, electron, SRF, acceleration	160
	S. Huang, J.E. Chen, S. Chen, K.X. Liu, S.W. Quan, Zh.W. Wang, X.D. Wen, F. Zhu PKU, Beijing, People's Republic of China
	The DC-SRF photoinjector at Peking University is capable of providing CW electron beam with the energy of 3-5 MeV. The beam has high repetition rate, picosecond bunch length and high quality, which can be used to produce high repetition rate THz wave by wiggler radiation. Through off-crest acceleration, electron beam from the injector may be bunched, which will lead to coherent enhancement of the radiation power. With current setup of the DC-SRF injector and a 10-period wiggler, THz radiation power of 10s mW to a few watts can be achieved within the wavelength range of 200 μm to 500 μm. In this work, we will present the calculation results about THz radiation produced by the electron beam from DC-SRF photoinjector. The preparation for the experiments will be also described.

MOPEA044	Maintenance Experience for Personnel Safety System at SSRF	controls, PLC, synchrotron, synchrotron-radiation	175
	J.J. Lu, P. Fei, G. Wang, X. Xia, J.Q. Xu, X.J. Xu SINAP, Shanghai, People's Republic of China
	To improve reliability and reduce faults of Personal Safety System (PSS) at Shanghai Synchrotron Radiation Facility (SSRF), two types of system maintenances were carried out since SSRF completion in 2009. The maintenances include maintenance during machine operation and that during shutdown period. The failures of the PSS are summarized for last 3 years operation, and the causes of these failures are analyzed. Main failures were occurred in the access control system and UPS power-supply mode during last 3 years operation. To treat these failures, detail maintenance plan and system upgrading schemes were carried out. After the maintenance and system upgrading, the numbers of beam shutdown which caused directly by the PSS failures are obviously reduced. It was 4 times beam shutdown in 2009 and 0 in 2011.

MOPEA058	CNGS, CERN Neutrinos to Gran Sasso, Five Years of Running a 500 Kilowatt Neutrino Beam Facility at CERN	target, proton, extraction, kaon	211
	E. Gschwendtner, K. Cornelis, I. Efthymiopoulos, A. Pardons, H. Vincke, J. Wenninger CERN, Geneva, Switzerland I. Krätschmer HEPHY, Wien, Austria
	The CNGS facility (CERN Neutrinos to Gran Sasso) aims at directly detecting muon to tau neutrino oscillations where an intense muon-neutrino beam (10¹⁷ muon-neutrinos/day) is generated at CERN and directed over 732km towards the Gran Sasso National Laboratory, LNGS, in Italy, where two large and complex detectors, OPERA and ICARUS, are located. The CNGS facility (CNGS Neutrinos to Gran Sasso) started with the physics program in 2008 and delivered until the end of the physics run 2012 more than 80% of the approved protons on target (22.5·10¹⁹ pot). An overview of the performance and experience gained in operating this 500kW neutrino beam facility is described. Major events since the commissioning of the facility in 2006 are summarized. Highlights on the CNGS beam performance are given.

MOPFI017	SuperKEKB Positron Source Target Protection Scheme	target, positron, electron, simulation	315
	L. Zang, T. Kamitani KEK, Ibaraki, Japan
	The SuperKEKB requires an intense beam with a large number of positrons, which is generated by a high energy electron beam strike on a solid tungsten target. The cascade shower in the target deposits large amount of energy in the material leading to target damage. The pulsed electron beam distributed the energy non-uniformly over the target. In that case, a mechanical stress appears due to the large thermal gradient during each pulse, which could potentially destroy the target. Based on the analysis of the SLAC damaged target, peak energy deposition density (PEDD) should not exceed 35 J/g to ensure a long term of safe operation. One way of reducing PEDD is increasing the beam spot size. Hence we proposed a target protection scheme, in which a protection target is placed upstream of generation target as a spoiler. The aim is to maintain the generation target’s PEDD below 35 J/g even with a point primary electron beam. In this paper, we will introduce graphite, aluminum and copper as the protection target material candidates. And also present the PEDD and positron yield evaluation as a function of various parameters such as protection target thickness and drift space.

MOPFI024	Ultra-short Electron Bunch Generation by an ECC RF Gun	gun, electron, laser, cathode	330
	Y. Koshiba, T. Aoki, M. Mizugaki, K. Sakaue, M. Washio Waseda University, Tokyo, Japan T. Takatomi, J. Urakawa KEK, Ibaraki, Japan
	Funding: Work supported by JSPS Grant-in-Aid for Young Scientists (B) 23740203 and Scientific Research (A) 10001690 Energy Chirping Cell attached rf gun (ECC rf gun) is a photocathode rf gun specialized for ultra-short bunch generation. This ECC rf gun has been made with the collaboration of High Energy Accelerator Research Organization (KEK). Although the bunch length could be controlled by the laser pulse width, the bunch length ends up to be more than 1ps due to space charge effect when using a femto-second laser and a normal 1.6 cell cavity. Concerning this phenomenon, ECC is attached right after the 1.6 cell so that the electron bunch would be compressed after the electron bunch is accelerated around 5MeV. The roll of ECC is to chirp the energy with the linear part of the rf electric field. The electron bunch would be compressed by velocity difference as it drifts. Simulation results from PARMELA and GPT show that ECC rf gun can accelerate an 100pC bunch with the bunch length less than 100fs. We already manufactured this ECC rf gun and installed in our system. We demonstrated the ultra-short bunch by measuring the coherent THz light by synchrotron radiation and transition radiation. In this conference, we will report the results of ultra-short bunch generation experiments, and future plans.

MOPFI026	Thermal Simulations of a New Target Configuration for Production of Radioactive Nuclide	target, neutron, simulation, ion	336
	L.H. Chen, B.Q. Cui, Q.H. Huang, W. Jiang, R. Ma, Y.J. Ma, B. Tang CIAE, Beijing, People's Republic of China
	China Advanced Rare Ion-beam Facility (CARIF) based on China Advanced Research Reactor (CARR) has been proposed in order exploring the frontier of nuclear physics. A target with 5 g 235U is proposed in the project. The thermal neutron fission of 235U will produce radioactive nuclei and the great thermal load (~50 kW). The target of CARIF needs endure high temperature and thermal energy deposit. A new multi-targets configuration is proposed. It consists of several discrete targets instead of traditional single-target structure used in accelerator driven facility. Because there is more thermal radiation area in this configuration, thermal radiation capacity is enhanced, so the target can withstand higher thermal power. The temperature distribution of multi-targets was simulated with finite element code. The results show that the configuration of multi targets can effectively reduce the target temperature. From the perspective of target temperature distribution, the configuration could endure 50kW thermal deposit. It's possible to use 5 g 235U in CARIF for production of radioactive nuclide.

MOPFI038	Generation and Measurement of Sub-picosecond Electron Bunch in Photocathode RF Gun	laser, electron, emittance, acceleration	372
	W.W. Li, Z.G. He, R. Huang, Q.K. Jia, G. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	The generation of subpicosecond electron bunch in the photocathode rf gun was considered and simulated by improving the acceleration gradient of the gun, suitably tuning the charge of the electron bunch and the acceleration phase. To measure the length of the electron bunch, the design of a nondestructive bunch length measurement technology was also presented in this paper.

MOPFI039	The Design of a Compact THz Source Based on Photocathode RF Gun	electron, gun, emittance, space-charge	375
	W.W. Li, Z.G. He, R. Huang, Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	Narrow-band THz coherent Cherenkov radiation can be driven by a subpicosecond electron bunch traveling along the axis of a hollow cylindrical dielectric-lined waveguide. We present a scheme of compact THz radiation source based on the photocathode rf gun. On the basis of our analytic result, the subpicosecond electron bunch with high charge (800pC) can be generated directly in the photocathode rf gun. A narrow emission spectrum peaked at 0.24 THz with 2 megawatt (MW) peak power is expected to gain in the proposed scheme (the length of the facility is about 1.2 m), according to the analytical and simulated results.

MOPFI070	Spallation is not the only Fruit: Low Energy Fusion as a Source of Neutrons	neutron, target, proton, simulation	443
	S.C.P. Albright, R. Seviour University of Huddersfield, Huddersfield, United Kingdom
	Commercially there is a growing interest in applications of neutrons. Currently the majority of neutron sources are based at research institutions from either reactors or spallation sources. Smaller portable sources contain either fissile isotope or sealed fusors are available, although they either use or produce tritium, or other long lived decay products. As an alternative to the large facilities and the radio-toxicology of current portable sources research is being performed with an aim to produce a fusion based neutron source with neither of these concerns. We show that MCNPX is able to accurately reproduce (p,n) reactions for a number of light elements. Simulations of low energy proton reactions with light nuclei simulated with MCNPX and Geant4 are compared with experiment.

MOPME010	Transverse Beam Profile Diagnostics using Point Spread Function Dominated Imaging with Dedicated De-focusing	electron, target, background, focusing	488
	G. Kube, S. Bajt DESY, Hamburg, Germany W. Lauth IKP, Mainz, Germany Yu.A. Popov, A. Potylitsyn, L.G. Sukhikh TPU, Tomsk, Russia
	Transverse beam profile diagnostics in electron accelerators is usually based on direct imaging of a beam spot via optical radiation (transition or synchrotron radiation). In this case the fundamental resolution limit is determined by radiation diffraction in the optical system. A method to achieve resolutions beyond the diffraction limit is to perform point spread function (PSF) dominated imaging, i.e. the recorded image is dominated by the resolution function of a point source (single electron), and with knowledge of the PSF the true image (beam spot) may be reconstructed. To overcome the limited dynamical range of PSF dominated imaging, a dedicated de-focusing of the optical system can be introduced. In order to verify the applicability of this method, a proof-of-principle experiment has been performed at the Mainz Microtron MAMI (University of Mainz, Germany) using optical transition radiation. Status and results of this experiment will be presented.

MOPME011	Investigation of the Applicability of Parametric X-ray Radiation for Transverse Beam Profile Diagnostics	photon, diagnostics, electron, background	491
	G. Kube, C. Behrens DESY, Hamburg, Germany A.S. Gogolev, Yu.A. Popov, A. Potylitsyn TPU, Tomsk, Russia W. Lauth IKP, Mainz, Germany S. Weisse DESY Zeuthen, Zeuthen, Germany
	Transverse beam profile diagnostics in electron linacs is widely based on optical transition radiation (OTR) as standard technique which is observed in backward direction when a charged particle beam crosses the boundary between two media with different dielectric properties. The experience from modern linac based light sources like LCLS or FLASH shows that OTR diagnostics might fail because of coherence effects in the OTR emission process. A possibility to overcome this limitation is to measure at much shorter wavelengths, i.e. in the X-ray region, using parametric X-ray radiation (PXR) which additionally offers the advantage to be generated at crystal planes oriented under a certain angle to the crystal surface, thus allowing a spatial separation from a possible COTR background . A first test experiment has been performed at the Mainz Microtron MAMI (University of Mainz, Germany) in order to study the applicability of PXR for beam diagnostics, and the status of this experiment will be presented. A. Gogolev, A. Potylitsyn, G. Kube, Journal of Physics 357 (2012) 012018

MOPME049	Status of Non-destructive Bunch Length Measurement based on Coherent Cherenkov Radiation	electron, target, diagnostics, vacuum	583
	H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang SINAP, Shanghai, People's Republic of China G.A. Naumenko, A. Potylitsyn, M.V. Shevelev, D.A. Shkitov TPU, Tomsk, Russia
	Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the Chinese NSFC 11175240. As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented. * Shevelev M. et al., Journal of Physics: Conf. Ser. 357 (2012) 012023.

MOPME053	Point Spread Function Study of X-ray Pinhole Camera in SSRF	synchrotron, synchrotron-radiation, emittance, storage-ring	592
	Z.C. Chen, J. Chen, G.Q. Huang, Y.B. Leng SSRF, Shanghai, People's Republic of China
	Funding: Supported by National Natural Science Foundation of China (11075198) An X-ray Pinhole Camera that has been used to present the transverse beam size with an intuitive grasp of the distribution of the beam radiation was installed on one beam-line of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). The real beam size however is a function of the image size of the CCD camera and the point spread function (PSF) of the system. The PSF was calculated but poorly tested. This article will present the measurement of the PSF with a series of beam based experiments and the consistency with the theoretical beam size.

MOPME060	Introduction to Beam Diagnostics Components for PAL-ITF	electron, diagnostics, laser, gun	610
	H. J. Choi, M.S. Chae, J.H. Hong, C. Kim, D.T. Kim, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) is building the 4th generation X-ray free electron laser (XFEL). The Injection Test Facility (ITF) is a test facility established to improve the functions of the laser gun and pre-injector to be installed in XFEL. To improve the effects of ITF, two factors are required. The first is to be able to generate low-emittance electron beams stably at the laser gun, and the second is to control increasing emittance by space charge effect by accelerating electron beams with high energy at the pre-injector. In this way, high-quality electron beams can be materialized. Various beam diagnostics are installed in the accelerator system for beam diagnostics and measurements. Five kinds of beam diagnostics were installed in the PAL-ITF. These are (1) ICT and (2) Faraday Cup to measure current and electrons charge, (3) Stripline BPM to measure the location of beams, (4) a YAG/OTR Screen Monitor to measure beam energy and transverse profile motion and (5) a Wire Scanner to measure beam size. In this paper, the purposes and properties of each diagnostic unit and measurement results are introduced.

MOPME061	Femtosecond e-bunch Length Measurement at fs-THz Accelerator at PAL	electron, linac, laser, gun	613
	J.H. Ko, I.S. Ko POSTECH, Pohang, Kyungbuk, Republic of Korea H.-S. Kang PAL, Pohang, Kyungbuk, Republic of Korea
	Longitudinal distribution of femto-second electron beam has been evaluated by the coherent transition radiation Michelson interferometer with the reconstruction procedure from interferograms. We measure the bunch length of the Thz Accelerator using interferogram method in Pohang Accelerator Lab and compare with the energy of transition radiation and bunch length.

MOPME062	UV and X-ray Diffraction Radiation for Submicron Noninvasive Diagnostics	diagnostics, target, polarization, electron	616
	D.Yu. Sergeeva, M.N. Strikhanov, A.A. Tishchenko MEPhI, Moscow, Russia
	Funding: This work was partially supported by Russian Ministry of Education and Science (State contract 12.527.12.5002). Diffraction radiation (DR) arises when a charged particle moves near a target. The theory of X-ray DR from single particles was created in [, ], and recently the theory has been developed for bunches [*]. DR from relativistic particles is used for noninvasive bunch diagnostics and also for creating new and effective sources of radiation, including Free-electron laser based on the Smith-Purcell effect. In the present work we explore theoretically DR from the bunch of ultrarelativistic charged particles at X-ray and UV frequencies domains. It is shown that incoherent part of form-factor, describing the effect of N electrons in bunch, exists and differs from the unity. The coherent part of radiation depends on transversal size of the bunch as ratio of the Bessel function to its argument. The coherence effects are proved to be important up to the wavelengths much less than transversal size of the bunch. The results obtained open the possibility to diagnose bunches of the submicron size with very high accuracy. A.A. Tishchenko et al, PLA. 359 (2006) 509. A.P. Potylitsyn et al, Diffraction radiation from relativistic particles, Springer, 2010 * D.Yu. Sergeeva et al, Proc. Channeling-2012, p.52, 2012

MOPME063	Backward X-ray Transition Radiation from Multilayered Target for Submicron Beam Diagnostics	target, diagnostics, polarization, electron	619
	A.A. Tishchenko, D.Yu. Sergeeva, M.N. Strikhanov MEPhI, Moscow, Russia K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom
	Funding: This work was partially supported by Russian Ministry of Education and Science (State contract 12.527.12.5002). Backward transition radiation (TR) is a TR arising in the direction of mirror reflection relative to the charged particles trajectory. Therefore for oblique incidence it can be emitted under big angles which is useful from point of view of measuring of the radiation. In spite of the fact that backward TR in X-ray frequency domain is much weaker than forward TR [], it has recently been proposed by A.P. Potylitsyn and others [] as an instrument for submicron electron beam diagnostics. In this work we propose to use the multilayered target in order to enhance the resulting radiation, i.e. to use resonant backward X-ray TR. So far X-ray TR has not been explored theoretically for backward geometry. It is shown that the expressions obtained coincide in special case of forward resonant X-ray TR with the results by L. Durand () and X. Artru (*). We explore the spectral and angular characteristics of resonant backward X-ray TR form point of view of submicron beam diagnostics for the ultrarelativistic charged particles bunches. The role of absorption in the target material and also the coherent and incoherent parts of the radiation is analyzed A.A. Tishchenko et al, NIMB 227 (2005) 63. L.G. Sukhikh et al, J of Phys: Conf. Ser. 236 (2010) 012011. * L. Durand, Phys Rev D11 (1975) 89. **** X. Artru et al, Phys Rev D12 (1975) 1289.

MOPME064	SLM and Flags for Booster of NSLS-II	booster, vacuum, synchrotron, synchrotron-radiation	622
	O.I. Meshkov, V. Smalyuk BINP SB RAS, Novosibirsk, Russia V.L. Dorokhov BINP, Novosibirsk, Russia
	Set of diagnostics of booster of NSLS-II includes 6 fluorescent screens (flags) and 2 synchrotron light monitors (SLM). The flags will be applied during booster commissioning for closing of the beam turn. They are also a useful tool in case of malfunction elimination. SLM will be used both for booster comissioning and for operation. The details of calibration and design of the devices are discussed.

MOPME065	Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object	vacuum, optics, diagnostics, scattering	625
	A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin Saint-Petersburg State University, Russia
	Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation. Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well. A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066	Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial	vacuum, diagnostics, lattice, optics	628
	A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev Saint-Petersburg State University, Russia
	Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation. The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches*. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch. A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011). **V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME067	Non-Invasive Bunch Length Diagnostics Based on Interferometry From Double Diffraction Radiation Target	target, electron, diagnostics, FEL	631
	D.A. Shkitov, G.A. Naumenko, A. Potylitsyn, M.V. Shevelev TPU, Tomsk, Russia H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang SINAP, Shanghai, People's Republic of China
	Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the SINAP Xinrui Program Y15501A061. Reliable and precise non-invasive beam diagnostics technique to measure length of sub-picosecond electron bunches are required for new accelerator facilities (FEL, et al.). Investigations of coherent radiation generated by such bunches using different interferometers allow to determine a bunch length. Measuring a dependence of radiation yield intensity from two DR targets on a distance between them (the intrinsic DR interferogram), it is possible to obtain the same information. Such a non-invasive technique can be directly used for ultra-short bunch length measurements. Recently the first experiment with a double DR target was carried out at the SINAP fs linac facility* with parameters described in**. The double DR target was consisted of two plates made from Al foil. The pyro-electric detector SPI-D-62 was used. Here we report the results of the second stage of our investigations. The DR interferograms of different electron bunch length were measured. The bunch length was reconstructed using the heuristic model based on the dimension theory and simulation data. We compare the results from DR interferograms and Michelson interferometer measurements and show their similarity. Murokh A. et al., NIMA 410 (1998) 452. Zhang J.B., Shkitov D.A. et al., IBIC’12 MOPB65 (2012). *Lin X., Zhang J. et al., Chin. Phys. Let. V. 27 N. 4 (2010) 044101.

MOPME068	Feasibility Study of a 2nd Generation Smith-Purcell Radiation Monitor for the ESTB at SLAC	simulation, background, electron, vacuum	634
	N. Fuster Martinez, A. Faus-Golfe, J. Resta-López IFIC, Valencia, Spain H.L. Andrews LANL, Los Alamos, New Mexico, USA F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S.R. Stevenson JAI, Oxford, United Kingdom J. Barros, N. Delerue, M. Grosjean LAL, Orsay, France V. Bharadwaj, C.I. Clarke SLAC, Menlo Park, California, USA
	The use of a radiative process such as the Coherent Smith-Purcell Radiation (CSPR) is a very promising non-invasive technique for the reconstruction of the time profile of relativistic electron bunches. Currently existing CSPR monitors do not have yet single-shot capability. Here we study the feasibility of using a CSPR based monitor for bunch length measurement at the End Station Test Beam (ESTB) at SLAC. The aim is to design a second-generation device with single-shot capability, and use it as a diagnostic tool at ESTB. Simulations of the spectral CSPR energy distribution and feasibility study have been performed for the optimization of the parameters and design of such a device.

MOPME071	Characterisation of Si Detectors for use at 2 Kelvin	proton, cryogenics, luminosity, superconducting-magnet	643
	M.R. Bartosik, C. Arregui Rementeria, B. Dehning, T. Eisel, C. Kurfuerst, M. Sapinski CERN, Geneva, Switzerland V. Eremin, E. Verbitskaya IOFFE, St. Petersburg, Russia
	Funding: This research project has been supported by a Marie Curie Early Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract nr PITN-GA-2011-289485-OPAC. It is expected that the luminosity of the Large Hadron Collider (LHC) will be bounded in the future by the beam loss limits of the superconducting magnets. To protect the superconducting magnets of the high luminosity insertions an optimal detection of the energy deposition by the shower of beam particles is necessary. Therefore beam Loss Monitors (BLM) need to be placed close to the particle impact location in the cold mass of the magnets where they should operate in superfluid helium at 1.9 Kelvin. To choose optimal detectors n-type silicon wafers have been examined at superfluid helium temperature whilst under irradiation from a high intensity proton beam. The radiation hardness and leakage current of these detectors were found to be significantly improved at 1.9 Kelvin when compared to their operation at room temperature.

MOPWA003	New Development of Compact Fast Pulsed Power Supply System in the SPring-8	power-supply, kicker, high-voltage, pulsed-power	666
	C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan T. Ohshima RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.

MOPWA021	Design of the Air Cooling System for the High Voltage Power Supply of a Electron Accelerator	power-supply, high-voltage, simulation, electron	705
	F. Zhong, X. Lei, J. Yang, L. Yang HUST, Wuhan, People's Republic of China
	High voltage electron accelerators are widely applied in many fields of radiation pro-cessing,and the high voltage power supply is the critical equipment for the accelerator. for the requirement of high voltage, the design of locate the power supply in a steel barrel filled with SF6 is commonly used. Considering the various losses of the power supply, an air-cooling system is needed. This paper presents the design of the air-cooling system for the high voltage power supply. The fluid simulation of SF6 based on Fluent and the optimal design of the air duct's structure and the thermal efficiency have been done. The comparison and analysis of the simulation and the empirical formula result is also carried out. It illustrates the design of the air-cooling system can satisfy the demand of the heat radiation This paper also provides an effective method for the optimal design of the air duct's structure and the maximize efficiency of heat exchange.

MOPWA041	The New SLS Beam Size Monitor, First Results	laser, emittance, polarization, synchrotron	759
	Á. Saá Hernández, N. Milas, M. Rohrer, V. Schlott, A. Streun PSI, Villigen PSI, Switzerland Å. Andersson, J. Breunlin MAX-lab, Lund, Sweden
	Funding: This research has received funding from the European Commission under the FP7-INFRASTRUCTURES-2010-1/INFRA-2010-2.2.11 project TIARA (CNI-PP). Grant agreement no. 261905. An extremely small vertical beam size of 3.6 μm, corresponding to a vertical emittance of 0.9 pm, only about five times bigger than the quantum limit, has been achieved at the storage ring of the Swiss Light Source (SLS). The measurement was performed by means of a beam size monitor based on the imaging of the vertically polarized synchrotron radiation in the visible and UV spectral ranges. However, the resolution limit of the monitor was reached during the last measurement campaign and prevented further emittance minimization. In the context of the work package “SLS Vertical Emittance Tuning” of the TIARA collaboration, a new improved monitor was built. It provides larger magnification, an increase of resolution and enables two complementary methods of measurement: imaging and interferometry. In this paper we present the design, installation, commissioning, performance studies and first results obtained with the new monitor.

MOPWA051	ZEMAX Simulations for an Optical System for a Diffraction Radiation Monitor at CesrTA	target, simulation, electron, damping	789
	T. Aumeyr, V. Karataev JAI, Egham, Surrey, United Kingdom M.G. Billing CLASSE, Ithaca, New York, USA L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland
	Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The target atoms are polarized by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to various electron beam parameters. Since the energy loss due to DR is so small that the electron beam parameters are unchanged, DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be studied. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. This paper reports on simulations carried out with ZEMAX, studying the optical system used to image the emitted radiation.

MOPWA056	Spectra of Coherent Smith-Purcell Radiation Observed from Short Electron Bunches: Numerical and Experimental Studies	electron, diagnostics, simulation, target	801
	F. Bakkali Taheri, G. Doucas, I.V. Konoplev, A. Reichold JAI, Oxford, United Kingdom H.L. Andrews LANL, Los Alamos, New Mexico, USA R. Bartolini Diamond, Oxfordshire, United Kingdom V. Bharadwaj, C.I. Clarke SLAC, Menlo Park, California, USA N. Delerue LAL, Orsay, France N. Fuster Martinez IFIC, Valencia, Spain J.D.A. Smith TXUK, Warrington, United Kingdom P. Stoltz Tech-X, Boulder, Colorado, USA
	Funding: This work performed [in part] under DOE Contract DE-AC02-7600515 There is a significant interest in the development of compact particle accelerators within research areas including X-ray and THz (T-ray) sources of radiation, particle physics and medical sciences. To support the progress in these areas, non-invasive, electron beam diagnostics that are capable of measuring a single femtosecond electron bunch are required. At the current stage such beam diagnostics for femtosecond-long electron bunches are still not available. The goal of the work presented is to understand the spectral characteristics of coherent Smith-Purcell radiation to enable its quick and reliable interpretation including the longitudinal profile reconstruction of electron bunches. The research presented comprises results from numerical modelling and experimental studies. Using the numerical data, we discuss the radiated spectra dependence on the electron bunch profile and analyse the results. We also discuss the experimental data and compare it with theoretical predictions.

MOPWA063	Proposed Coherent Diffraction Radiation Measurements of Bunch Length at ASTA	electron, cryomodule, gun, laser	822
	A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The feasibility of using the autocorrelation of coherent diffraction radiation (CDR) as a non-intercepting diagnostics technique for bunch length and indirectly rf phase measurements is evaluated and proposed for the Advanced Superconducting Test Accelerator (ASTA) facility under construction at Fermilab. Previous experiments on an rf thermionic cathode gun beam at 50 MeV provide a proof-of-principle reference for the ASTA injector. The ASTA injector is based on an L-band rf photocathode (PC) gun with UV pulse drive laser, two L-band superconducting accelerator structures, a chicane bunch compressor, and an electron spectrometer. The injector energy of 40-50 MeV is expected. The 3-MHz micropulse repetition rate with micropulse charges up to to 3.2 nC and 1-ps bunch lengths should generate sufficient CDR signal for standard pyroelectric detectors to be used. The CDR signals will also be evaluated as a bunch compression signal for beam-based feedback for rf phase. The technique would also be applicable at high energy in straight transport lines after the cryomodules.

MOPWA073	A Turn-by-turn Beam Profile Monitor using Visible Synchrotron Radiation at CESR-TA	electron, synchrotron, synchrotron-radiation, emittance	849
	S. Wang, D. L. Rubin, C.R. Strohman CLASSE, Ithaca, New York, USA R.F. Campbell, R. Holtzapple CalPoly, San Luis Obispo, California, USA
	Funding: Work supported by the National Science Foundation and Department of Energy under contract numbers PHY-0734867, PHY-1002467, DMR-0936384, and DE-FC02-08ER41538, DE-SC0006505 A fast beam profile monitor using visible synchrotron radiation (SR) has been constructed and installed in Cornell Electron Storage Ring. This monitor utilizes fast readout electronics based on the Hamamatsu H7260K multi-anode photomultiplier, which has a 32-channel linear array with 1mm channel pitch and sub-nanosecond rise time. In a low emittance lattice at 2 GeV, a double-slit interferometer is employed to measure the horizontal beam size. After careful calibration of the interference pattern, the horizontal beam size within a range of 100 to 500 microns can be measured with a precision of ±5 microns. Due to finite array size, the small vertical beam size is measured by imaging the pi-polarized component of the SR. The fast beam profile monitor is capable of measuring bunch-by-bunch turn-by-turn transverse beam sizes, which eliminates beam jitter inherent when imaging the average beam size with a CCD camera. Details of hardware and software controls are also discussed.

MOPWA080	Design of a Fast, XFEL-quality Wire Scanner	photon, electron, vacuum, instrumentation	867
	M.A. Harrison, R.B. Agustsson, P.S. Chang, T.J. Hodgetts, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, USA
	RadiaBeam Technologies, in collaboration with the Pohang Accelerator Laboratory, has designed and built a fast wire scanner for transverse beam size measurements in the XFEL Injector Test Facility. The wire scanner utilizes three 25-micron diameter tungsten wires mounted vertically, horizontally, and diagonally on a single alumina card to measure the transverse beam size down to 10 microns with sub-micron accuracy of a 139-MeV electron beam. A double-ended design using dual bellows for actuation is used to reduce the vibrations of the wire holder during motion and negate the effects of air pressure on positioning. The servomotor-driven system is capable of performing full horizontal, vertical, and 45-degree scans in under a minute. Algorithms are presented for removing the broadening effect of the wires' thickness from the scanning data to measure beams that are as small or smaller than the wires. Furthermore, we present formulas for determining the beam's transverse spatial sizes (horizontal and vertical spot size and correlation) from the scan data.

MOPWO003	Multibunch Tracking Code Development to Account for Passive Landau Cavities	cavity, electron, damping, impedance	885
	M. Klein, R. Nagaoka SOLEIL, Gif-sur-Yvette, France
	The MAX IV 3 GeV storage ring will achieve an ultra-low horizontal emittance of 0.24 nm rad by using a multibend achromat lattice. Passive harmonic cavities are introduced to relax the Touschek-lifetime and intrabeam scattering issues as well as fight collective beam instabilities via Landau damping. Since instabilities occur during injection, when the passive harmonic cavity potential is also time varying, it became important to simulate this transient process. The most promising approach was considered to be multibunch tracking which also allows for an arbitrary filling pattern. Since every bunch is represented by numerous macroparticles, internal motions as well as microstructures in the charge distribution can be followed.

MOPWO029	Remote Estimate of Collimator Jaw Damages with Sound Measurements during Beam Impacts	proton, simulation, background, extraction	951
	D. Deboy, O. Aberle, R.W. Aßmann, F. Carra, M. Cauchi, J. Lendaro, A. Masi, S. Redaelli CERN, Geneva, Switzerland
	Irregular hits of high-intensity LHC beams on collimators can lead to severe damage of the collimator jaws. The identification of damaged collimator jaws by observation of beam measurements is challenging: online loss measurements at the moment of the impacts can be tricky and degradation of the overall performance from single collimator damage can be difficult to measure. Visual inspections are excluded because collimator jaws are enclosed in vacuum tanks without windows. However, the sound generated during the beam impact can be used to give an estimate of the damage level. In 2012, high-intensity beam comparable to a full nominal LHC bunch at 7 TeV was shot on a tertiary type LHC collimator at the HiRadMat test facility at CERN. The paper presents results from sound recordings of this experiment.

MOPWO037	SixTrack Simulation of Off-momentum Cleaning in LHC	simulation, synchrotron, betatron, synchrotron-radiation	972
	E. Quaranta, R. Bruce, S. Redaelli CERN, Geneva, Switzerland
	In the LHC, high-amplitude particles are cleaned by either betatron collimators or momentum collimators. Previously, betatron losses have been considered more important, but measurements during the first years of operation show high losses also in the off-momentum cleaning insertion. This causes a significant radiation dose to warm magnets downstream of the collimators. Our work in this paper aims at simulating with SixTrack the off-momentum particles, driven into the momentum collimators by radiation damping outside the RF system acceptance. The results are an important ingredient in assessing the effectiveness of new passive absorbers to protect the warm magnets.

MOPWO051	Estimate of Warm Magnets Lifetime in the Betatron and Momentum Cleaning Insertions of the LHC	luminosity, betatron, insertion, collimation	1011
	B. Salvachua, R. Bruce, M. Brugger, F. Cerutti, S. Redaelli CERN, Geneva, Switzerland
	The CERN LHC collimation system is designed to perform momentum and betatron cleaning in different insertions, respectively IR3 and IR7. The insertions are not perfectly decoupled because the dispersion in IR7 is not null and the beta function in IR3 is not zero. The detailed sharing of losses between the two insertions depends on the relative collimator settings as observed by the change between 2011 and 2012 LHC operation. In this report, using the beam loss measurements at the primary collimators of IR3 and IR7, the total BLM losses in the two insertions are calculated and compared to each other. These studies are also used to quantify the total dose to warm magnets in those IRs with the aim to understand better their lifetime and the implications of the radiation to electronics. This will be of particular importance in view of LHC operating at nominal performance after several years of operation.

MOPWO063	LHeC IR Optics Design Integrated into the HL-LHC Lattice	optics, quadrupole, proton, dipole	1034
	M. Korostelev, D. Newton, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom O.S. Brüning, R. Tomás CERN, Geneva, Switzerland E. Cruz Alaniz, D. Newton, A. Wolski The University of Liverpool, Liverpool, United Kingdom
	The two main drivers for the CDR LHeC IR design were chromaticy and synchrotron radiation. Recently it has been proposed that the LHeC IR proton optics could be integrated into the ATS scheme, which benefits from higher arc beta functions for the correction of chromaticity. In this scenario the distance between the IP and the protron triplet can be increased allowing for a reduction of the IR dipole field and the synchrotron radiation. First feasibility considerations and more in depth studies of the synchrotron radiation effects are presented in this paper.

TUXB201	Short-pulse Operation of Storage Ring Light Sources	storage-ring, electron, photon, optics	1129
	A.-S. Müller KIT, Karlsruhe, Germany
	Short-pulse operation of synchrotron light source storage rings can be useful for both the production of IR and THz-band radiation and high repetition rate pump-probe science in the X-ray regime. Different approaches to short-pulse generation include low-alpha optics configurations, two-frequency RF potential manipulation, laser-induced femtoslicing, longitudinal crab-cavity deflection and pseudo-bunch operation with a fast kicker to isolate a single bunch. This talk should review each of these techniques and discuss implications for machine operation in terms of pulse length, beam intensity, beam stability, pulse repetition rate, output radiation beam quality and potential applications.
	Slides TUXB201 [12.058 MB]

TUPEA001	Generation of Anomalous Intensive Transition Radiation for FEL	electron, dipole, lattice, polarization	1161
	K.B. Oganesyan, A.S. Gevorkyan, E.M. Sarkisyan ANSL, Yerevan, Armenia Y. Rostovtsev University of North Texas, Denton, Texas, USA
	The 3D spin-glass system in the external standing electromagnetic field is considered. It is shown on an example of amorphous quartz, under the influence of a standing microwave field, at its certain parameters, superlattice is created in the medium where difference in values of dielectric constants of neighboring layers can be up to third order. Note that this superlattice exists during the nanosecond however it is sufficient for using it as a radiator for generation of transition radiation by relativistic electrons.

TUPEA005	Effects of Quantum Diffusion on Electron Trajectories and Spontaneous Synchrotron Radiation Emission	electron, photon, undulator, synchrotron	1170
	I.V. Agapov, G. Geloni XFEL. EU, Hamburg, Germany O.V. Chubar BNL, Upton, Long Island, New York, USA
	For various cases, e.g. in the long undulator sections of the European XFEL, quantum diffusion and energy loss have a noticable effect on the electron trajectory, which in turn affects the properties of the emitted radiation. We discuss approaches to modelling the electron dynamics taking this into account and the effect it has on spontaneous radiation emission.

TUPEA006	Towards Realistic Modelling of the FEL Radiation for the European XFEL	simulation, FEL, controls, undulator	1173
	I.V. Agapov, G. Geloni XFEL. EU, Hamburg, Germany
	For the operation phase of the European XFEL the possibility to characterize the FEL radiation taking realistic machine model into account is important. To achieve this, a software framework is being developed. It allows for interoperability of various simulation codes by means of a common graphical user interfaces, common input and output files, and common programming model for scripting; it includes the possibility of modeling beam jitters and machine imperfections to set errorbars on the simulation results, and has a connection to the control system for data acquisition. We report on the progress in the developing of this framework and give examples of FEL property calculations performed with it.

TUPEA007	Spontaneous Radiation Calculations for the European XFEL	undulator, electron, emittance, FEL	1176
	I.V. Agapov, G. Geloni XFEL. EU, Hamburg, Germany O.V. Chubar BNL, Upton, Long Island, New York, USA M. Scheer, M. Titze HZB, Berlin, Germany N.V. Smolyakov, S.I. Tomin NRC, Moscow, Russia
	Calculating spontaneous radiation emission from long undulators such as those present in the European XFEL, being background to FEL radiation, is still important for several diagnostics and science cases. For realistic setups, and including effects of electron beam focusing, emittance and energy spread in the electron beam, these calculations should be performed numerically. We present these calculations for several electron beam and undulator parameters performed by various codes. Sensitivity of different spontaneous radiation characteristics, in various collection schemes, to the electron beam and undulator magnetic field parameters is studied

TUPEA030	High Brightness and Fully Coherent X-ray Pulses from XFELO Seeded High-gain FEL Schemes	FEL, electron, cavity, undulator	1214
	H.X. Deng, C. Feng SINAP, Shanghai, People's Republic of China
	The successful operation of the hard x-ray self-seeding experiment at the LCLS opens the era of fully coherent hard x-ray free electron lasers (FELs). However, the shot-to-shot radiation fluctuation is still a serious issue. In this paper, high-gain, single-pass x-ray FEL schemes seeded by the narrow bandwidth radiation signal from an x-ray FEL oscillator were proposed and investigated, which are expected to generate high brightness, fully coherent and stable x-ray pulse. A simple model has been developed to figure out the temporal and the spectral structures of the output pulses in x-ray FEL oscillator. And options using two synchronized accelerators and using one accelerator were considered, respectively.

TUPEA033	Proposals for Chirped Pulse Amplification in HGHG and CHG at SDUV-FEL	FEL, laser, electron, undulator	1217
	C. Feng, L. Shen, D. Wang, D. Xiang, M. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	In this paper, a proposal to generate intense ultra-short free-electron laser (FEL) pulses at Shanghai deep ultraviolet FEL (SDUV-FEL) by combining the chirped pulse amplification (CPA) technique with the high-gain harmonic generation (HGHG) technique is presented. In this proposal, a frequency chirped seed pulse obtained by stretching an ultra-short laser pulse is first used to create frequency-chirped bunching at the laser harmonics in an electron beam; then the frequency chirped harmonic radiation is amplified by an energy chirped electron beam; finally the output radiation pulse which inherits the properties of the seed pulse is compressed to provide an ultra-intense ultra-short radiation pulse. The feasibility and performance of this CPA-HGHG scheme are studied with start-to-end simulations using the parameters of the SDUV-FEL.

TUPEA049	Wakefields of Ultrarelativistic Bunches in Cold Magnetized Plasma	wakefield, plasma, electron, acceleration	1241
	S.N. Galyamin, A.V. Tyukhtin Saint-Petersburg State University, Russia
	Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation. We deal with electromagnetic field of various bunches moving in a cold magnetized plasma along the external magnetic field. The main attention is paid to the case of ultrarelativistic motion. First, for the case of point charge, we obtain the approximate formulas which are valid in the far-field zone and in the vicinity of the charge trajectory. These expressions predict the beating behavior of the far field and the harmonic behavior of the near field. Moreover, the magnitude of the longitudinal components of both electric and magnetic field as well as the transversal electric field possess singularity on the charge trajectory. Second, using formulas for the point charge field as Green function, we develop an effective algorithm for calculation of the bunch wakefield. Plots of wakefields produced by typical bunches are given. Prospects of using the bunch field properties for further development of the plasma wakefield acceleration technique are discussed.

TUPEA061	High-Brightness SASE Studies for the CLARA FEL	undulator, FEL, electron, simulation	1274
	R.N.C. Santer, N. Thompson STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The Compact Linear Accelerator for Research and Applications (CLARA) is a proposed 250 MeV FEL test facility to be constructed at STFC Daresbury Laboratory in the UK [1]. This paper presents study of a scheme for the temporal and spectral stabilisation of the SASE output. A feasibility study for the operation of the FEL in a novel High-Brightness SASE mode is presented. Electron beam delays are introduced between undulator sections to disrupt the localised collective FEL process, increase the radiation coherence length and reduce the rms bandwidth. This may extend the range of electron bunch lengths appropriate for the generation of temporally coherent single spike SASE FEL pulses.

TUPEA074	Protection of VUV FEL Mirrors using Soft Orbit Bump at Duke FEL/HIGS facility	FEL, wiggler, electron, dipole	1301
	S.F. Mikhailov, H. Hao, J.Y. Li, V. Popov, P.W. Wallace, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DoE grant # DE-FG02-97ER41033 The Duke FEL and High Intensity Gamma-ray Source (HIGS) facility is operated with an electron beam from 0.24 to 1.2 GeV and a photon beam from 190 to 1060 nm. Presently, the energy range of the gamma-beam is from 1 MeV to about 100 MeV, with the maximum total gamma-flux of more then 10¹⁰ gammas per second around 10 MeV. Production of high intensity, high energy gamma-beams of 60 to 100 MeV, using UV-VUV mirrors of 240 to 190 nm, requires high energy, high current electron beams of 0.9 to 1.05 GeV. Synchrotron radiation damage to the FEL mirrors becomes crucial for VUV FEL operation at or below 190 nm. The edge radiation (ER) from the End-of-Arc (EOA) bending magnet, instead of the radiation of FEL wigglers, is the dominant cause of a rapid degradation of the downstream FEL mirror. In this work, we describe a further development of the “soft” orbit bump concept to significantly reduce the radiation exposure to the mirror from the EOA dipole magnet. The bump uses designated "soft" orbit correctors with magnetic field limited to produce a radiation with a critical wavelength close or below the FEL wavelength.

TUPFI005	Synchrotron-Radiation Photon Distribution for Highest Energy Circular Colliders	photon, scattering, vacuum, electron	1340
	G.H.I. Maury Cuna CINVESTAV, Mérida, Mexico G. Dugan, D. Sagan CLASSE, Ithaca, New York, USA F. Zimmermann CERN, Geneva, Switzerland
	Funding: Acknowledgements to CINVESTAV, CERN and EPLANET project. At high energies, beam-induced synchrotron radiation is an important source of heating, beam-related vacuum pressure increase, and primary photoelectrons, which can give rise to an electron cloud. The photon distribution along the beam pipe wall is a key input to codes such as ECLOUD and PyECLOUD, which model the electron cloud build-up. For future high-energy colliders, like TLEP or SHE-LHC, photon stops and antechambers are considered in order to facilitate cooling and vacuum pressure control. We use the Synrad3D code developed at Cornell to simulate the photon distribution for the LHC.

TUPFI013	LHC Long Shutdown: A Parenthesis for a Challenge	cryogenics, controls, vacuum, superconducting-magnet	1355
	K. Foraz, M. Arnaud, M.B.M. Barberan Marin, C. Bedel, M. Bernardini, J. Coupard, J. Etheridge, H. Gaillard, S. Grillot, E. Paulat, A.-L. Perrot CERN, Geneva, Switzerland
	After three fruitful years of operation, the LHC will enter a long shutdown. Major works will be implemented to allow running safely at 7TeV/beam. The LHC superconducting circuits will be consolidated; mitigation measures will be carried out to reduce the single event effects occurrence in the frame of the Radiation To Electronics mitigation project (R2E); all the equipment will be fully maintained. In parallel, numerous consolidation and upgrade activities will be performed all around the 27km ring. The schedule has been optimized in order to reduce the length of the shutdown (LS1) to 22 months (including hardware commissioning). The organization of the works is therefore essential to ensure a safe and reliable plan. This paper introduces the various activities to be performed and presents the schedule and the preparation process, including the operational safety aspects.

TUPFI021	FLUKA Energy Deposition Studies for the HL-LHC	luminosity, quadrupole, shielding, optics	1379
	L.S. Esposito, F. Cerutti, E. Todesco CERN, Geneva, Switzerland
	The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches. O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.*

TUPFI042	Beam Parameters and Luminosity Time Evolution for an 80-km VHE-LHC	emittance, luminosity, damping, collider	1442
	C.O. Domínguez, F. Zimmermann CERN, Geneva, Switzerland
	The Very High Energy LHC (VHE-LHC) is a recently proposed proton-proton collider in a new 80-km tunnel. With a dipole field of 15-20 T it would provide a collision energy of 76-100 TeV c.m. We discuss the VHE-LHC beam parameters and compute the time evolution of luminosity, beam current, emittances, bunch length, and beam-beam tune shift during a physics store. The results for VHE-LHC are compared with those for HE-LHC, a 33-TeV (20-T field) collider located in the existing LHC tunnel.

TUPFI062	Operational Results of the LHC Luminosity Monitors until LS1	luminosity, proton, monitoring, simulation	1490
	A. Ratti, S.C. Hedges, J. Jones, H.S. Matis, M. Placidi, W.C. Turner, V.K. Vytla LBNL, Berkeley, California, USA E. Bravin, F. Roncarolo CERN, Geneva, Switzerland R. Miyamoto ESS, Lund, Sweden
	Funding: Work funded by the US Department of Energy through the US- LARP program. The monitors for the high luminosity regions in the LHC have been operating since 2009 to optimize the LHC's luminosity. The devices are gas ionization chambers inside the neutral particle absorber 140 m from the interaction point and monitor showers produced by high energy neutral particles from the collisions. They have the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. The devices have operated on a broad range of luminosity, from the initial 10²⁸ until the levels well beyond 10³³ reached in 2012. We present operational results of the device during proton and lead ion operations until LS1, which include runs at 40 MHz bunch rate and with p-Pb collisions.

TUPME011	Simulated Beam-beam Limit for Circular Higgs Factories	luminosity, synchrotron, simulation, beam-beam-effects	1586
	K. Ohmi KEK, Ibaraki, Japan F. Zimmermann CERN, Geneva, Switzerland
	We report simulation studies of the beam-beam limit for two proposed circular e⁺e⁻ Higgs factories with circumference of 27 and 80 km, respectively, called LEP3 and TLEP. In particular we investigate the dependence of the steady-state luminosity and transverse beam sizes on the synchrotron tune (or momentum compaction factor) and on the betatron tunes, as well as the consequences of the strong radiation damping and the implications of the large hourglass effect.

TUPME013	Coherent Thomson Scattering using Beam Echo	laser, electron, scattering, undulator	1592
	K. Ohmi, S. Kamada KEK, Ibaraki, Japan H. Fares Kanazawa University, Kanazawa, Japan
	Longitudinal phase space of the beam is modulated by laser interacting in undulators. The beam can have higher frequency component using the beam echo than than the laser as dicussed by G. Stupakov et al. The modulated beam has a potential to emit coherent radiation with the wave length. We evaluate coherent short wave length (~nm) and/or short pulse (attosec) light source using the beam echo in a low energy accelerator ~100MeV.

TUPME027	Advanced Studies on New Generation of Electron-positron Accelerators and Colliders for Fundamental and Applied Researches	laser, electron, FEL, gun	1631
	A. Dudarev, N. Balalykin, U.A. Budagov, V. Kobets, M.V. Lyablin, B.M. Sabirov, G. Shirkov, E. Syresin, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia
	JINR actively leads the R&D works in particle accelerator physics and engineering, construction of the free electron laser with the aim to prepare proposals for the project of JINR participation in international collaboration on construction of the future Linear Collider (CLIC/ILC). JINR scientists and engineers study in free electron laser physics, development and construction of systems applied for formation and diagnostics of ultra short dense bunches in the linear electron accelerators. JINR physicists also take part in several fields of activity in ILC: works on photo injector prototype, participation in design and construction of cryomodules, laser metrology, and possible ILC location near Dubna.

TUPME029	VEPP-4: Application Beyond the High Energy Physics	electron, positron, collider, target	1637
	O.I. Meshkov BINP SB RAS, Novosibirsk, Russia
	The current status of VEPP-4M electron-positron collider has been described. During fall of 2011 the accelerator was shut down for planned reconstruction of KEDR detector. The next long run of the collider will be dedicated to the experiments at high energy physics within area of 2-5 GeV. Nevertheless, the set of experiments at booster VEPP-3 were continued. VEPP-3 was operated as an SR source, the experiment with internal target was performed and electron/positron scattering at proton was studied. The short runs of VEPP-4M were used as for commissioning of the new “warm” 3T wiggler as for experiments with an extracted electron beam dedicated for testing of different high energy physics detectors. The experiment of comparing of anomalous magnetic moment of electron and positron is con-tinued at VEPP-4M. The system of RF beam shifting is installed at a straight section of the accelerator. It is applied for elimination of parasitic interaction points of electron and positron beams. The first experiments with this system are described. KEDR detector reconstruction should be finished at autumn of 2013. The future experiments with KEDR detector are discussed.

TUPWA024	The Beam Gass Coulomb Scattering in Electron Storage Ring	scattering, simulation, electron, synchrotron	1778
	X.L. Yu, Z. Bai, W.W. Gao, W. Li, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Among the various factors which determine the beam life time of the HLSII electron storage ring, the beam loss due to the scattering on residual gas is simulated using MC method. The paper will give the process of elastic and inelastic scattering, and the probability of each scattering is calculated, then using MC sampling to decide which particles will participate in the collision. Tracking the beam with scattering of beam-gas included, the spatial distribution of beam will be obtained. Finally we will give the influence analysis of beam-gas scattering.

TUPWA057	Effects of Transient CSR Wakefields on Microbunching in a Bunch Compressor	wakefield, impedance, lattice, FEL	1832
	C.E. Mitchell, J. Qiang LBNL, Berkeley, California, USA
	Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The standard analytical model of CSR-induced microbunching in a bunch compressor chicane makes use of a steady-state 1-D model of the longitudinal CSR interaction. This model is numerically generalized to include the effects of transient CSR wakefields due to bend entry and exit, as well as CSR that is generated in upstream bends and propagates across one or more lattice elements before interacting with the beam. The resulting linear integral equation for CSR-induced microbunching is solved numerically for the second bunch compressor of a proposed Next Generation Light Source.

TUPWA069	Longitudinal Phase Space Dynamics with Novel Diagnostic Techniques at FACET	linac, wakefield, klystron, damping	1865
	S.J. Gessner, E. Adli, F.-J. Decker, M.J. Hogan, T.O. Raubenheimer SLAC, Menlo Park, California, USA A. Scheinker LANL, Los Alamos, New Mexico, USA
	Funding: Work supported [optional: in part] by the U.S. Department of Energy under contract number DE-AC02-76SF00515. FACET produces high energy density electron beams for Plasma Wakefield Acceleration (PWFA) experiments. The high energy density beams are created by chirping the electron beam with accelerating sections and compressing the beam in magnetic chicanes. Precise control of the longitudinal beam profile is needed for the drive-witness bunch PWFA experiments currently underway at FACET. We discuss the simulations, controls, and diagnostics used to achieve FACET's unique longitudinal phase space.

TUPWO003	CLIC 3 TeV Beam Size Optimization with Radiation Effects	quadrupole, lattice, dipole, photon	1877
	O.R. Blanco, P. Bambade LAL, Orsay, France R. Tomás CERN, Geneva, Switzerland
	Horizontal beamsize contribution due to radiation on bending magnets is calculated using theoretical results and recent improvements in mapclass (Mapclass2). In order to verify the code and validity of its approximations, a simple lattice with no geometrical nor chromatic aberrations, one dipole and a final drift has been used to compare Mapclass2 calculations and Placet tracking results. CLIC 3TeV lattice is optimized including the radiation effects. Current results show that correction of chromatic aberrations impose constraints in radiation improvement.

TUPWO013	Non-linear Beam Transport Optics for a Laser Wakefield Accelerator	undulator, focusing, electron, optics	1907
	C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner KIT, Karlsruhe, Germany O. Jäckel, M. Kaluza, M. Reuter HIJ, Jena, Germany M. Kaluza, M. Nicolai, T. Rinck, A. Sävert IOQ, Jena, Germany M. Scheer HZB, Berlin, Germany
	Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2 The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented.

TUPWO061	Design of a Soft Orbit Bump for FEL Mirror Protection at Duke FEL/HIGS Facility	FEL, electron, synchrotron, synchrotron-radiation	2006
	H. Hao, J.Y. Li, S.F. Mikhailov, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033. In an oscillator Free-Electron Laser (FEL) with a high energy electron beam, it is critical to minimize harmful high-energy radiation on the downstream FEL mirror in order to increase its lifetime. At the High Intensity Gamma-ray Source (HIGS) facility at Duke University, effort has been devoted to developing a variety of techniques to reduce the amount of radiation on the FEL mirror. One of the most effective methods was the use of a set of adjustable in-vacuum apertures to block harmonic radiation from FEL wigglers. In recent studies, it was determined that the edge radiation from the end-of-the-arc bending magnet is the main source of UV/VUV and x-ray radiation which causes mirror damage. To mitigate this effect, a soft orbit bump is designed to change the displacement and angle of the electron beam around the end-of-the-arc area. This soft orbit bump is developed using the multi-objective optimization technique. Calculation shows the soft orbit bump can significantly reduce the flux of high energy photons on the FEL mirror. Study is also performed to determine the impact of this orbit bump on the injection, beam lifetime, and the FEL and gamma-ray operation at HIGS facility.

WEZB102	Overview of Seeding Methods for FELs	FEL, electron, undulator, laser	2063
	S. Reiche PSI, Villigen PSI, Switzerland
	In recent years enormous progress has been achieved in the theoretical understanding and experimental demonstration of FEL seeding. The state of the art for FEL seeding should be reviewed and compared to HHG, HGHG, EEHG techniques. The potential of various seeding methods and their promise to produce radiation pulses that approach the transform limit in a range of experimental configurations at different user facilities should be explored.
	Slides WEZB102 [4.238 MB]

WEODB101	X-ray Spectra and Peak Power Control with iSASE	FEL, undulator, electron, laser	2068
	J. Wu, F.-J. Decker, Y. Feng, J. Krzywinski, H. Loos, A.A. Lutman, A. Marinelli, H.-D. Nuhn, C. Pellegrini, D.F. Ratner, D.H. Zhang, D. Zhu SLAC, Menlo Park, California, USA
	Funding: Work is supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515. We report the first measurement of spectral line-width reduction in a self-amplified spontaneous emission (SASE) X-ray free-electron laser (FEL) obtained by introducing repeated delays of the electron bunch with respect to the radiation field pulse. The improved longitudinal coherence obtained by this method reduces the intensity spiking effect characteristic of a SASE FEL. The electron-photon delays introduced along the FEL undulator mix the spikes phase and amplitude, increasing the cooperation length and generating a smaller bandwidth than in the conventional SASE mode of operation of an FEL. We call this mode of operation, based on repeated electron-photon delays, ‘‘improved SASE'' (iSASE). We also show with theoretical and simulation analysis that in the iSASE mode it is possible to choose the separation and magnitude of the delays to obtain a nearly transform limited X-ray pulse. This analysis is carried out using a time dependent, one-dimensional model and with GENESIS numerical simulation, including three-dimensional effects.
	Slides WEODB101 [7.647 MB]

WEOBB202	Ultra-fast Data Acquisition System for Coherent Synchrotron Radiation Based on Superconducting Terahertz Detectors	synchrotron, electron, controls, storage-ring	2094
	C.M. Caselle, M. Hofherr, K.S. Ilin, V. Judin, A. Kopmann, A. Menshikov, A.-S. Müller, M. Siegel, N.J. Smale, P. Thoma, M. Weber, S. Wuensch KIT, Eggenstein-Leopoldshafen, Germany B.M. Balzer, S. Cilingaryan Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
	The ANKA synchrotron radiation source located at the Karlsruhe Institute of Technology in Germany operates in the energy range between 0.5-2.5GeV and provides coherent synchrotron radiation. To resolve the ultra-short terahertz pulses emitted by a single bunch, thin YBCO superconducting film detectors have been developed. A response time of 45ps was determined as the FWHM at the output of the analog amplifier. A novel and high accuracy data acquisition architecture for sampling of the individual ultra-short terahertz pulses combined with real-time data processing based on GPUs for coherent synchrotron radiation is presented. The digitizer board is a made-in-house board designed for sampling of the fast pulse signals with pulse width between few tens of picosecond until 100ps. For each terahertz pulse five samples are acquired with a minimum sampling time of 3ps. A prototype setup with terahertz YBCO detectors, digitizer boards and the high-throughput FPGA framework has been successfully developed and tested at ANKA. The overview of the experimental setup including the YBCO detector technology and the preliminary results with single and multi-bunch filling pattern will be discussed.
	Slides WEOBB202 [2.416 MB]

WEIB201	Industrial Accelerators	electron, ion, neutron, linac	2100
	R.W. Hamm, M.E. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	Particle accelerators, originally developed for basic science research, are increasingly being employed for industrial applications, with the production of these systems itself a worldwide business conducted by more than 70 companies and institutes. Collectively these entities ship more than 1000 systems per year. The industrial applications of these accelerators cover a broad range of business segments from low energy electron beam systems for welding, machining, and product irradiation to high energy cyclotrons and synchrotrons for radioisotope production and synchrotron radiation production. This talk is a review of these business segments and their impact on our lives and the economy. It will also cover new accelerator technology under development that will be used by industry in the future and the predicted growth in the various business segments.
	Slides WEIB201 [3.937 MB]

WEIB205	Promoting Local Economic Development by an Integration of Industry, Teaching and Research of Compact Low Energy Accelerators	electron, permanent-magnet, high-voltage, HOM	2119
	M. Fan, D.Z. Chen, J. Huang, D. Li, K.F. Liu, B. Qin, Y.Q. Xiong, J. Yang, T. Yu HUST, Wuhan, People's Republic of China H.Q. Gao Hubei University of Science and Technology, Hubei, People's Republic of China
	Huazhong University of Science and Technology has been carrying out R&D of compact low energy accelerators by integrating industry, teaching and research to promote local economic development supported by both national and provincial government and local enterprises. Currently, the projects include: compact medical cyclotron, electron irradiation accelerators, etc. The industry of non-power nuclear energy based on low energy particle accelerator has also drawn attention from the provincial government of Hubei and municipal government of Xianning. Meanwhile, a series of lectures about nuclear science and nuclear safety were hosted to help the public better understand nuclear technology and to wipe out fears of nuclear energy. At the moment, the application of non-power nuclear energy with based on compact low energy accelerator is developing into an industry chain in the area of central China.
	Slides WEIB205 [2.311 MB]

WEPWA001	Wigglers at Danfysik	wiggler, electron, damping, emittance	2123
	C.W.O. Ostenfeld, M. Pedersen Danfysik A/S, Taastrup, Denmark
	In the past 2 years, a number of insertion devices have been designed, assembled and tested at Danfysik. They are used for a variety of applications at free electron lasers and synchrotron radiation facilities. In this paper, we highlight 3 different wiggler projects: A 2.0 T wiggler for Astrid-II in Århus, Denmark, a fixed-gap electromagnetic wiggler for Helmholtz Center Dresden-Rossendorf, and 6 identical damping wigglers for NSLS-2 at Brookhaven National Laboratory (BNL). For the Astrid-2 facility in Aarhus, Denmark, we have designed and built a 6 period wiggler, with a peak field of 2.0 T. The magnetic design and performance is presented and discussed. As part of the ELBE THz facility, at Helmholtz Center Dresden-Rossendorf, we have designed and built a fixed-gap electromagnetic wiggler, with 300 mm period length, and a peak field of 0.39 T. We present the design and magnetic results. For the NSLS-2 project at BNL, damping wigglers are an integral part of the design, both as a means of reducing the emittance, but also as a source of intense radiation sources for users. We present the mechanical and magnetic design, as well as magnetic results obtained for the wigglers.

WEPWA005	Experimental Characterization of the Coherent Harmonic Generation Source at the DELTA Storage Ring	laser, electron, undulator, synchrotron	2132
	M. Huck, H. Huck, M. Höner, S. Khan, R. Molo, A. Schick, P. Ungelenk DELTA, Dortmund, Germany S. Cramm, L. Plucinski, C.M. Schneider Forschungszentrum Jülich, Peter-Gruenberg-Institut-6, Jülich, Germany S. Döring, L. Plucinski, C.M. Schneider Universität Duisburg-Essen, Duisburg, Germany
	Funding: Work supported by DFG, BMBF, and by the Federal State NRW. The short-pulse facility at the 1.5-GeV synchrotron light source DELTA, operated by the TU Dortmund University, generates coherent VUV and THz radiation by Coherent Harmonic Generation (CHG). Here, a femtosecond laser pulse interacts with an electron bunch in an undulator causing a periodic energy modulation and subsequent micro-bunching, which gives rise to coherent radiation at harmonics of the seed wavelength. Rather than using Ti:Sapphire laser pulses at 795 nm directly, the second harmonic is employed for seeding since 2012. After significant modifications of the seed laser beamline and the dispersive chicane to improve the microbunching, the last commissioning steps include characterization of the CHG radiation and preparing the experimental setup at an existing VUV beamline for time-resolved photoemission spectroscopy. In this paper, the status of the project and recent experimental results are presented.

WEPWA006	Beam Heat Load Measurements with COLDDIAG at the Diamond Light Source	electron, synchrotron, synchrotron-radiation, impedance	2135
	S. Gerstl, S. Casalbuoni, A.W. Grau, T. Holubek, D. Saez de Jauregui, R. Voutta KIT, Eggenstein-Leopoldshafen, Germany R. Bartolini, M.P. Cox, E.C. Longhi, G. Rehm, J.C. Schouten, R.P. Walker Diamond, Oxfordshire, United Kingdom M. Migliorati, B. Spataro INFN/LNF, Frascati (Roma), Italy
	Understanding the heat load from an electron beam is still an open issue for the cryogenic design of superconducting insertion devices. COLDDIAG, a cold vacuum chamber for diagnostics was designed and built specially for this purpose. With the equipped instrumentation, which covers temperature sensors, pressure gauges, mass spectrometers as well as retarding field analyzers it is possible to measure the beam heat load, total pressure, and gas content as well as the net flux and energy of particles hitting the chamber walls. Following a failure after its first installation in November 2011, COLDDIAG was subsequently reinstalled in the Diamond storage ring in August 2012. We report on the preliminary results that have been obtained since then.

WEPWA007	First Tests with a Local and Integral Magnetic Field Measurement Setup for Conduction Cooled Superconducting Undulator Coils	undulator, synchrotron, vacuum, synchrotron-radiation	2138
	A.W. Grau, S. Casalbuoni, S. Gerstl, N. Glamann, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany
	The magnetic field quality of insertion devices (IDs) has a significant influence on their performance. Therefore it is essential to characterize their magnetic properties and perform precise field measurements before installation in synchrotron light sources. Particularly for permanent magnet IDs the magnetic field measurement technology made significant progress during the last years and pushed the capabilities of synchrotron light sources. Even though for superconducting IDs the measurement settings are far more challenging similar major developments are required. As a part of our R&D program on superconducting IDs we perform quality assessment of their magnetic field properties. This contribution describes details, challenges and the first tests with the measurement equipment configurations to perform measurements of the integral and local magnetic field distributions of superconducting undulator coils up to 2 m length, in a cold (4.2 K), in-vacuum and cryogen free environment.

WEPWA010	FLUTE: A Versatile Linac-based THz Source Generating Ultra-short Pulses	linac, laser, gun, electron	2147
	M.J. Nasse, E. Huttel, S. Marsching, A.-S. Müller, S. Naknaimueang, R. Rossmanith, R. Ruprecht, M. Schreck, M. Schuh, M. Schwarz, P. Wesolowski KIT, Karlsruhe, Germany R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb DESY, Hamburg, Germany H.-H. Braun, R. Ganter, L. Stingelin PSI, Villigen PSI, Switzerland
	FLUTE is a linac-based accelerator test facility and a THz source currently being constructed at KIT with an electron beam energy of ~41 MeV. It is designed to cover a large charge range from a few pC to ~3 nC. FLUTE is optimized to provide ultra-short electron bunches with an RMS length down to a few fs. In this contribution, we focus on the layout of the machine from the RF gun & gun laser over the linac and the compressor to the THz beamline for the generation of coherent synchrotron, transition and edge radiation (CSR, CTR, CER).
	Poster WEPWA010 [0.802 MB]

WEPWA022	The Fabrication and Measurement of the New Insertion Devices of Hefei Light Source	undulator, vacuum, insertion, insertion-device	2177
	Q.K. Jia USTC/NSRL, Hefei, Anhui, People's Republic of China
	To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more new insertion devices. The new insertion devices include one elliptically polarizing undulator with 10⁴ mm period, one in-vacuum undulator with 40mm period, one wiggler with 152mm period and one quasi-periodic undulator based on a new scheme proposed by us. In this paper the fabrication and the preliminary results of the magnetic field measurements of the new insertion devices are reported.

WEPWA024	Study of an Electron Gun for Terahertz Radiation Source	gun, electron, cathode, focusing	2184
	J. Li, C. Li, Y.J. Pei, L. Shang USTC/NSRL, Hefei, Anhui, People's Republic of China Q.S. Chen, T. Hu HUST, Wuhan, People's Republic of China G. Feng DESY, Hamburg, Germany
	With the aim to obtain short-pulse bunches with high peak current for a terahertz radiation source, an RF gun with independently tunable cells (ITC) was employed. As the electron source of the ITC RF gun, a grid-control DC gun plays a key role, the performance of which determines the beam quality in the injector and transport line. In order to make the beam well compressed in the ITC RF gun, the energy of the electrons acquired from the grid-control DC gun should be 15 KeV at most. A proper structure of the grid-gun is shown to overcome the strong space charge force on the cathode, which is able to generate 1us beam with 4.5A current successfully. Simulations considering the grid net are also introduced.

WEPWA038	Influence of Magnet Errors and Waveguide Permeability on Magnetic Field Performance in Pure Permanent Undulators	undulator, FEL, permanent-magnet, simulation	2214
	X. Liu, K.F. Liu, B. Qin, P. Tan, B. Wu, Y.Q. Xiong, J. Yang, L. Yang HUST, Wuhan, People's Republic of China
	Abstract For pure permanent magnet (PM) undulator, unavoidable divergences of remanence field and magnetization vector in PM blocks and installation error will cause magnetic field error at the central line of the undulator. This paper presents the simulation results of the magnetic field in non-ideal undulator containing these errors, with specified tolerances in Normal distribution. As well as the peak field error, increases of the harmonic components and impact on field integrals are calculated. The influence on magnetic field caused by waveguide permeability is also discussed.

WEPWA044	Electron Trajectories in a Three-dimensional Undulator Magnetic Field	undulator, electron, focusing, simulation	2223
	N.V. Smolyakov, S.I. Tomin NRC, Moscow, Russia G. Geloni XFEL. EU, Hamburg, Germany
	In this contribution we present an analysis of electron trajectories in the three dimensional magnetic field from a planar undulator. The electron trajectory is influenced by the focusing properties of the undulator field. In the European XFEL case, long segmented undulators (21 segments for the SASE3 beamline to 35 for SASE1 and SASE2) are planned to be installed, with quadrupole lenses between different segments. These focusing properties should be taken into account in simulations of spontaneous radiation, which constitutes the background signal of the FEL. The ideal magnetic field of an undulator can be described by a sinusoidal vertical magnetic field on the undulator axis, and by horizontal and longitudinal field components that appear out of axis. Exploiting this description for the ideal case, an experimentally measured magnetic field is accounted for by solving the differential equations of motion. The electrons' trajectories for the experimentally measured magnetic field were also simulated numerically. To that aim, a computer code was written, which relies on the Runge-Kutta algorithm. The analytical and numerical methods show a good agreement.

WEPWA062	Status of the UK Superconducting Planar Undulator Project	undulator, cryogenics, vacuum, wakefield	2259
	J.A. Clarke, B.J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom V. Bayliss, T.W. Bradshaw, S.A. Brown, A.J. Brummitt, G.W. Burton, S.J. Canfer, B. Green, S.R. Watson STFC/RAL, Chilton, Didcot, Oxon, United Kingdom S.E. Hughes, E.C. Longhi, J.C. Schouten Diamond, Oxfordshire, United Kingdom
	The UK is developing a short period, narrow aperture, planar superconducting undulator that is planned to be installed and tested in the 3 GeV Diamond Light Source in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. First measurements will be presented of a 19 period test module and also the commissioning of the 2K cryogenic turret.

WEPWA073	Compton Scattering Gamma-ray Light Source Modeling and Optimization	electron, brightness, laser, photon	2283
	F.V. Hartemann, R.A. Marsh, S.S.Q. Wu LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 In Compton scattering light sources, a short (ps to ns) laser pulse and a high brightness relativistic electron beam collide to yield tunable, monochromatic, polarized gamma-ray photons. The properties of the gamma-ray phase space is studied, in relation to the full electron bunch and laser pulse phase spaces, along with collimation, nonlinear effects and other sources of spectral broadening. This process has potential high impact applications in homeland security, nuclear waste assay, medical imaging and stockpile surveillance, among other areas of interest. Detailed theoretical modeling is outlined to aid the design of Compton light sources and provide optimization strategies relevant within the context of nuclear photonics applications.

WEPWA077	Aperture Test for Internal Target Operation in the JLAB High-current ERL	FEL, target, electron, diagnostics	2289
	S. Zhang, S.V. Benson, G.H. Biallas, K. Blackburn, J.R. Boyce, D.B. Bullard, J.L. Coleman, J. Delk, D. Douglas, P. Evtushenko, C.W. Gould, J.G. Gubeli, F.E. Hannon, D. Hardy, C. Hernandez-Garcia, K. Jordan, J.M. Klopf, R.A. Legg, M. Marchlik, W. Moore, G. Neil, J. Powers, T. Powers, D.W. Sexton, M.D. Shinn, C. Tennant, R.L. Walker, G.P. Williams, F.G. Wilson JLAB, Newport News, Virginia, USA J. Balewski, J. Bernauer, W. Bertozzi, R.F. Cowan, P.F. Fisher, E. Ihloff, A. Kelleher, R. Milner, L. Ou, B.A. Schmookler, c. Tschalär MIT, Cambridge, Massachusetts, USA N. Kalantarians Hampton University, Hampton, Virginia, USA
	Funding: Supported by the Commonwealth of Virginia, U.S. DOE Nuclear and High Energy Physics, and by the U.S. DOE Basic Energy Sciences under contract No. DE-AC05-060R23177. A high current beam transmission test has been successfully completed at the JLAB FEL Facility, culminating in very low-loss transmission of a high current CW beam through a small aperture. The purpose of this test was to determine if an ERL is capable of meeting the stringent requirements imposed by the use of a 10¹⁸/cm³ internal gas target proposed for the DarkLight experiment. Minimal beamline modifications were made to create a machine configuration that is substantially different from those used in routine UV or IR FEL operation. A sustained (8 hour) high power beam run was performed, with clean transmission through a 2 mm transverse aperture of 127 mm length simulating the target configuration. A beam size of 50 um (rms) was measured near the center of the aperture. Experimental data from a week-long test run consistently exhibited beam loss of only a few ppm on the aperture while running 4.5 mA current at 100 MeV – or nearly 0.5 MW beam power. This surpassed the users’ expectation and demonstrated a unique capability of an ERL for this type of experiments. This report presents a summary of the experiment, a brief overview of our activities, and outlines future plans. References: P. Fisher, et al.,“Jlab PR-11-008: A Proposal for the DarkLight Experiment at the Jefferson Laboratory Free Electron Laser.” http://www.jlab.org/exp_prog/proposals/11prop.html

WEPWA080	Development of a Compact Insertion Device for Coherent Sub-mm Generation	linac, laser, impedance, wakefield	2295
	A.V. Smirnov, R.B. Agustsson, S. Boucher, T.J. Grandsaert, J.J. Hartzell, M. Ruelas, S. Storms RadiaBeam, Santa Monica, USA A. Andrews, B.L. Berls, C.F. Eckman, K. Folkman, A.W. Hunt, Y. Kim, A.E. Knowles-Swingle, C. O'Neill, M. Smith IAC, Pocatello, IDAHO, USA P. Buaphad, Y. Kim ISU, Pocatello, Idaho, USA
	Funding: Department of Energy Contracts DE- SC-FOA-0000760 and DE-FG02-07ER84877 A novel design of resonant Cherenkov wakefield extractor that produced a ~0.9 mm wavelength radiation is presented. The experiment was performed at Idaho Accelerator Center (IAC) using specially upgraded 1.3 GHz 44 MeV linac facility. Specifics of the radiator performance and design are outlined including low-energy beam interaction with non-circular geometry. Some elements of the design may have certain potential for future compact mm-sub-mm-wave sources.

WEPWA081	Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications	undulator, cryogenics, vacuum, simulation	2298
	F.H. O'Shea, R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods RadiaBeam, Santa Monica, USA J. Park, R.L. Stillwell NHMFL, Tallahassee, Florida, USA V. Solovyov BNL, Upton, Long Island, New York, USA
	The demand for high-brightness hard x-ray fluxes from next generation light sources has spurred the development of insertion devices with shorter periods and higher fields than is feasible with conventional materials and designs. RadiaBeam Technologies is currently developing a novel high peak field, ultrashort period undulator with praseodymium-iron-boron (PrFeB) permanent magnets and textured dysprosium (Tx Dy) ferromagnetic field concentrators. This device will offer an unparalleled solution for compact x-ray light sources, as well as for demanding applications at conventional synchrotron radiation sources. A 1.4T on-axis field has already been achieved in a 9mm period undulator, demonstrating the feasibility of using Tx Dy poles in a hybrid undulator configuration with PrFeB magnets. Facets of the undulator design, optimization of the Tx Dy production and characterization process, and magnetic measurements of Tx Dy will be presented.

WEPWO013	High Power Tests of Injector Cryomodule for Compact-ERL	cavity, cryomodule, HOM, accelerating-gradient	2340
	E. Kako, D.A. Arakawa, K. Hara, T. Honma, H. Katagiri, Y. Kojima, Y. Kondo, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Shishido, T. Takenaka, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan H. Hara, H. Hitomi, K. Sennyu MHI, Kobe, Japan
	In the cERL injector cryomodule, electron beams of 10 mA are accelerated from the beam energy of 500 keV to 5 MeV. A three 2-cell cavity system was chosen for the cERL injector. Each cavity is driven by two input couplers to reduce a required RF power handling capacity and also to compensate a coupler kick. In the cERL injector cryomodule, critical hardware components are not superconducting cavities but RF input couplers operating in CW mode. Six input couplers for the installation in the cryomodule were fabricated, and three pairs of input couplers were carefully conditioned. Costruction status, cool-down tests and high power RF test results on injector cryomodule for compact-ERL at KEK will be discussed in this paper.

WEPWO016	Construction of Main Linac Cryomodule for Compact ERL Project	HOM, cryomodule, cavity, linac	2349
	K. Umemori, K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	Compact ERL (cERL), which is a test facility of ERL, is under construction at KEK, in Japan. At the first stage of cERL project, electron beam will be accelerated by 30 MV at main linac region. We have developed a main linac cryomodule, which contains two L-band 9-cell superconducting cavities. Cavity assembly work was carefully done at a class-10 clean room and HOM absorbers and cold windows of input couplers were successfully mounted on the cavities. Next, the frequency tuners, thermal anchors, magnetic shields and temperature sensors and so on were assembled to the cryomodule. Then, using a clean-booth, warm windows of the input couplers are connected to the cold windows and gate valves were also attached to the both ends of the cryomodule. Finally, the cryomodule was installed into the beamline of cERL and connected to a 2K cryogenic system. Target of alignment precision of the cavities, after cooling down to 2K, are set to be within 1 mm against the beamline. The first cool-down test, followed by low power and high power measurements, is scheduled within the year 2012.

WEPEA011	Bursting Patterns of Coherent Synchrotron Radiation in the ANKA Storage Ring	impedance, simulation, electron, synchrotron	2516
	M. Schwarz, V. Judin, A.-S. Müller KIT, Karlsruhe, Germany M. Klein SOLEIL, Gif-sur-Yvette, France
	We report measurements of bursting patterns of coherent synchrotron radiation (CSR) for a wide range of single bunch currents at the ANKA storage ring. The radiation was detected with a fast THz detector, a Hot Electron Bolometer, and its signal acquired with both a spectrum analyzer and an external sampling oscilloscope. Both analysis methods consistently show the onset of bursting at a threshold current with the appearance of strong high frequency bands with higher harmonics in the several 10th of kHz range. For currents higher than twice the threshold value an abrupt change in the bursting pattern occurs. These results are compared with different numerical models solving the one-dimensional Vlasov-Fokker-Planck equation.

WEPEA027	Nonlinear Model Calibration in Electron Storage Rings via Frequency Analysis	sextupole, betatron, storage-ring, damping	2558
	G. Liu, W. Li, L. Wang, K. Xuan USTC/NSRL, Hefei, Anhui, People's Republic of China
	Frequency analysis of turn-by-turn BPM data is a very useful numerical method for analysing the detrimental effect of the nonlinear resonances in storage rings, and which has been widely used for nonlinear resonances measurement and correction. We applied this method in this paper for calibrating the nonlinear model by numerical fitting of the sextupole components with the effect of radiation damping and decoherence of the betatron oscillation in HLSII storage ring.

WEPEA041	Actions To Mitigate The Radiation Damage to Electronics at the LHC	shielding, hadron, controls, civil-engineering	2591
	A.-L. Perrot, M.B.M. Barberan Marin, J.-P. Corso, K. Foraz, M. Lazzaroni, Y. Muttoni CERN, Geneva, Switzerland
	The level of flux of hadrons with energy in the multi MeV range expected from the collisions at the LHC interaction Points 1, 5 and 8 and from the collimation system at Point 7 will induce Single Event Errors (SEEs) in the standard electronics present in many of the control equipment installed in LHC underground. Furthermore, a risk of SEEs induced by thermal neutrons cannot be excluded. Such events would perturb the LHC operation, possibly leading to a stop of the machine. Main mitigation actions will be implemented during the first LHC Long Shutdown of 2013/2014 (LS1) to reduce the SEE occurrence. This paper summarizes the mitigation measures and their associated foreseen improvements in terms of SEEs. It presents the organization process and associated planning highlighting the impacts with the overall LHC LS1 planning and the main concerns during implementation.

WEPFI036	R&D on a Main Accelerating Section of a Compact THz-FEL	electron, laser, FEL, simulation	2780
	W. Bai, M. Li, X. Shen, H. Wang, X. Yang CAEP/IAE, Mianyang, Sichuan, People's Republic of China
	In order to develop a tera-hertz(THz) radiation source and to make scientific researches on application of THz technology, a study on tera-hertz source is performed. The radiation source is based on technology of free electron laser(FEL). The energy booster section of the injector uses a 9 Cell standing wave accelerator as the main accelerator for the FEL. The accelerator works at S band.(2856 MHz), excited by a microwave power of about 3.5 MW. At the end of the accelerator, the high quality beam energy is of 6.5MeV ~ 7 MeV, and the current about 300 mA. This paper presents the newly prgress of the , as well as the working condition of the main accelerator.

WEPFI054	Enlargement of Tuning Range in a Ferrite-tuned Cavity through Superposed Orthogonal and Parallel Magnetic Bias	cavity, factory, resonance	2812
	C. Vollinger, F. Caspers CERN, Geneva, Switzerland
	Conventional ferrite-tuned cavities operate either with bias fields that are orthogonal or parallel to the magnetic RF-field. For a cavity that tunes rapidly over an overall frequency range around 100-400 MHz with high Q, we use ferrite garnets exposed to an innovative new biasing method consisting of a superposition of perpendicular and parallel magnetic fields. This method leads to a significant enlargement of the high-Q cavity tuning range by defining an operation point close to the magnetic saturation and thus improving ferrite material behaviour. A further advantage of this technique is the fast tuning speed resulting from the fact that tuning is carried out either with pure parallel biasing, or together with a very small change of operating point from perpendicular bias. In this paper, several scaled test models of ferrite-filled resonators are shown; measurements on the set-ups are compared and discussed.

WEPFI072	Analysis of Breakdown Damage in an 805 MHz Pillbox Cavity for Muon Ionization Cooling R&D	cavity, site, cathode, plasma	2857
	D.L. Bowring, D. Li LBNL, Berkeley, California, USA A. Moretti, Y. Torun Fermilab, Batavia, USA
	When operating in multi-Tesla solenoidal magnetic fields, normal-conducting cavities exhibit RF breakdown at anomalously low gradients. This breakdown behavior may be due to field-emitted electrons, focused by the magnetic field into "beamlets" with relatively large current densities. These beamlets may then cause pulsed heating and cyclic fatigue damage on cavity interior surfaces. If this model is correct, materials with long radiation lengths (relative to copper) may alleviate the problem of RF breakdown in strong magnetic fields. To study this phenomenon, RF breakdown was induced on pairs of "buttons" in an 805 MHz pillbox cavity. The shape of the buttons creates a local enhancement of the surface electric field, such that breakdown occurs preferentially on the button surface. Beryllium and copper buttons were tested in order to evaluate the effect of radiation length on RF breakdown performance. This poster presents an analysis of the damage to these buttons and suggests a path forward for future materials R&D related to breakdown in strong magnetic fields.

WEPME027	Analysis of Tidal Effects on Measurement Accuracy of HLS	alignment, site, synchrotron, synchrotron-radiation	2989
	S.F. Xu, X.Y. He, P. Wang, W. Wang, Q.Y. Yao USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Natural Science Foundation of China HLS* is mainly used in survey and high-accuracy alignment in particle accelerator. Monitoring the earth tides is primarily introduced in this paper. Based on the earth tide theory and the ocean load effects on the planet earth, the tidal effects on a hydrostatic leveling system is analyzed. Finally, the local ground deformation is obtained,and the current research establish a foundation for the further study. HLS-hydrostatic levelling system

WEPME055	Investigation of Source Point Instabilities in Dipole Magnet Based Beamlines	dipole, synchrotron, feedback, optics	3055
	M. Apollonio, R. Bartolini Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	At Diamond the source point in the second dipole of the Double Bend Achromats can vary due the lack of adjacent BPMs constraining angle and position of the electron beam at the dipole. We have implemented a code based on our AT model to predict the effects of a corrector strength change and compared our predictions to data both from a beamline and from our pinhole cameras. We discuss the possibility of interfacing the code to a ray tracing routine in order to infer beam spot changes in the downstream beamline and suggest a procedure to restore the original source point.

THOAB201	Development of the Dielectric Wall Accelerator	proton, dipole, simulation, shielding	3115
	A. Zografos, T. Brown, C. Cohen-Jonathan, C. Hettler, F. Huang, V. Joshkin, K. Leung, M. Moyers, Y.K. Parker, D. Pearson, M. Rougieri CPAC, Livermore, CA, USA R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton beam therapy. The Dielectric Wall Accelerator engineering prototype includes a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked transmission to produce the required voltage. The transmission lines are switched with solid state laser driven optical switches. A computational model has been developed that is in very good agreement with the experimental results. The system is presently achieving accelerating gradients of approximately 15 MeV/m. The computational model has been used to design the next generation system that will achieve 25 MeV/m by early 2013. This paper will discuss the status of the apparatus, the basic elements of the computational model, experimental results and comparison to the model predictions. In addition, the paper will present concepts for proton therapy systems that incorporate the Dielectric Wall Accelerator and fully leverage its features to achieve clinical requirements.
	Slides THOAB201 [1.650 MB]

THPPA03	The Development of China’s Accelerators I Have Experienced	proton, synchrotron, luminosity, linac	3144
	S.X. Fang IHEP, Beijing, People's Republic of China
	The development of China’s high energy accelerator for half a century falls into two stages, namely the first 20 hovering years (1958-1978) and the later 30 years of rapid development (from 1978 till now). I was lucky enough to have experienced the whole process, witnessed, and to some extent, joined in the decision-making, the projects approval, the designing, the development and construction of China's five large scientific facilities undertaken by the Institute of High Energy Physics in Beijing. A brief review is given of the previous stage of history regarding the consideration of China’s high energy accelerators in the first 20 years. A short presentation is also given of the later 30 years concerning the rapid development of the Beijing Electron-Positron Collider (BEPC and BEPCII), the completed BEPC-based Shanghai Synchrotron Radiation Facility (SSRF), the Chinese Spallation Neutron Source (CSNS) under construction, the high-intensity proton accelerator (ADS) used for nuclear waste transmutation and the proton therapy machine in the R&D stage.
	Slides THPPA03 [6.015 MB]

THPEA008	Study on the Energy Response of a Multi-layer Planar High Pressure Ionization Chamber using MCNP Program	photon, simulation, ion, electron	3164
	Y.D. Ding, P.F. Wang, Q.B. Wang, Q.J. Zhang IHEP, Beijing, People's Republic of China
	High pressure ionization chamber is widely used to detect various radiation fields due to its good energy response. A new Multi-layer planar high pressure ionization chamber is designed suitable for measuring directional radiation field of high dose rate, because of its high electric field strength. In this paper, MCNP program is used to simulate and calculate the energy response of this ionization chamber to obtain the energy response of high energy photons, which could not be obtained by experimental methods. The results show that this ionization chamber can measure photon radiation energy up to 10MeV.

THPEA015	Induced Radioactivity Research for Scraper	electron, radioactivity, linac, synchrotron	3173
	L.J. He, Y.K. Chen, W. Li USTC/NSRL, Hefei, Anhui, People's Republic of China
	The 200MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in China. The electrons are accelerated to 200MeV by five accelerating tubes and collimated by the scraper followed each accelerating tube. The scraper aperture is smaller than the accelerating tube,so some electrons will hit on the structure materials when they pass through them. These lost electrons will cause induced radioactivity due to bremsstrahlung, cascade shower and photo-nuclear reaction. This paper gives the simulation to different energy electrons lost at the corresponding scraper by EGSnrc. The results showed that electrons were lost mainly at the scraper during the accelerating period,and the actual measurement confirmed this. Meanwhile,the induced radionuclide types have been studied. Recently,the linac mentioned above has been retired because of upgrading. The equipments and materials removed are used to study induced radioactivity generated in different materials. The research will provide the theoretical basis for the similar accelerator decommissioning plan,and is also significant for accelerator structure design,material selection and radiation protection programs design.

THPEA026	Radiation Safety Interlock System for DCLS	controls, electron, monitoring, dipole	3198
	G. Wang, S. Liu, J.J. Lu, X. Xia, J.Q. Xu, Y. Xu, F. Yang SINAP, Shanghai, People's Republic of China
	Dalian Coherent Light Source (DCLS) is in the design phase currently and will be constructed in Dalian from 2013. It is a seeded HGHG-FEL, mainly consisting of one 300 MeV electron linear accelerator and one undulator. Radiation safety is one of the most important tasks for Dalian FEL. Radiation safety interlock system (RSIS) is designed to prevent personnel exposure to high radiation levels, based on the As Low As Reasonably Achievable (ALARA) principle. RSIS controls access to the radiation protection areas and monitors safety devices. Only if all the radiation safety conditions are satisfied, then the facility will be permitted to operate. Once any condition is broken, RSIS will send a signal to stop the electron beam immediately to guarantee radiation safety. The core component of RSIS utilizes Programmable Logic Controller (PLC), which is a proven and reliable technology in the field of industrial automatic control. All safety-relevant functions of RSIS are implemented with fail-safe components. The hard wiring cable of the peripheral signals for the safety-relevant functions is redundant. The safety interlock signals are sent via a fail-proof protocol and transferred redundantly.

THPEA027	Radiation Calculations for Advanced Proton Therapy Facility	shielding, proton, simulation, target	3201
	J.Q. Xu, J.J. Lu, G. Wang, X. Xia SINAP, Shanghai, People's Republic of China
	The shielding calculations for Advanced Proton Therapy Facility (APTRON), which is under design in Shanghai, were carried out. The thickness of radiation shielding walls for the accelerator and treatment rooms of APTRON were determined by Monte Carlo simulation and empirical formula. Beam loss scenarios and workloads of different energy at LINAC, synchrotron, beam transport line and treatment are given for the calculations. The calculations were carried out for the proton energy of 150MeV, 220MeV and 250MeV, and the targets of iron and equivalent tissue material. Source terms and attenuation length were calculated with different angles by the simulation using FLUKA code. Based on the source terms and the attenuation length, the thickness of the bulk walls were determined. Local shielding and maze design were also concerned.

THPEA039	Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN	linac, shielding, neutron, simulation	3225
	J. Blaha, J. Vollaire CERN, Geneva, Switzerland
	Linac4, a new 160 MeV H⁻ accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models.

THPEA040	Design of a Magnetic Bump Tail Scraping System for the CERN SPS	injection, beam-losses, extraction, closed-orbit	3228
	Ö. Mete, J. Bauche, F. Cerutti, S. Cettour Cave, K. Cornelis, L.N. Drøsdal, F. Galleazzi, B. Goddard, L.K. Jensen, V. Kain, Y. Le Borgne, G. Le Godec, M. Meddahi, E. Veyrunes, H. Vincke, J. Wenninger CERN, Geneva, Switzerland A. Mereghetti UMAN, Manchester, United Kingdom
	The LHC injectors are being upgraded to meet the demanding beam specification required for High Luminosity LHC (HL-LHC) operation. In order to reduce the beam losses which can trigger the sensitive LHC beam loss interlocks during the SPS-to-LHC beam injection process, it is important that the beam tails are properly scraped away in the SPS. The current SPS tail cleaning system relies on a moveable scraper blade, with the positioning of the scraper adjusted over time according to the orbit variations of the SPS. A new robust beam tail cleaning system has been designed which will use a fixed scraper block towards which the beam will be moved by a local magnetic orbit bump. The design proposal is presented, together with the related beam dynamics studies and results from machine studies with beam.

THPEA042	TREC: Traceability of Radioactive Equipment at CERN	HOM, controls, monitoring, background	3234
	M.P. Kepinski, L. Bruno, Ch. Delamare, S. Mallon Amerigo, P. Martel, S. Petit, T. Schmittler, M.J.S. Tavlet, D. Widegren CERN, Geneva, Switzerland
	Activated accelerator components are frequently removed from service due to changes in design, configuration or maintenance work. Safe and effective management of such components is a necessity. Moreover, local authorities require the tracking of this equipment: any piece of equipment or waste which has been in a potentially radioactive area must be controlled by a radio protection responsible before leaving the accelerator premises. CERN must also be able to prove that the required measurements have been done and are properly stored in a computerized system. TREC is the official system used at CERN to trace potentially radioactive equipment. It replaces paper work by electronic data, manual phone calls by automatic email notifications and helps to enforce CERN safety rules. Some of the major benefits are the reduction of the delays related to equipment movements (from installation to workshops or waste storage areas) as well as increased personal safety. The system is fully integrated with the CMMS* tools used at CERN to ensure the complete equipment lifecycle’s traceability. *CMMS: Computerized Maintenance Management System

THPEA043	An Equipment Hub for Managing a Small Town and a Complex Machine	controls, coupling, status, collider	3237
	P. Martel, A. Alexandre Metola, Ch. Delamare, M.P. Kepinski, S. Mallon Amerigo, L. Pater, S. Petit, D. Widegren CERN, Geneva, Switzerland
	Effective maintenance of the accelerators’ complex is vital for CERN’s mission. While this work is highly dependent on operational planning and constraints, it also needs to be coordinated with the maintenance of the infrastructure where the complex is embedded. The nature and degree of the logistics problems that arise from this interdependence cannot be handled by partial, decoupled solutions from each of the stakeholders. CERN’s Enterprise Asset Management system is the central hub where all relevant data about equipment and its maintenance is kept. It is also where data and documents about the manufacturing, installation, safety inspection, radiation measurements, disposal, etc. of the scientific equipment reside. This hub allows the effective sharing of consistent equipment data, accessed by a large number of people and systems, and supplies a wide range of interfaces – ranging from the user in the field with no access to a desktop computer, to scheduling systems that need to interact with it through Web services; this is achieved by means of a series of systems, tools and mechanisms, all dedicated to different needs but working on the same data and sharing common policies.

THPEA044	Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors	proton, cryogenics, beam-losses, monitoring	3240
	C. Kurfuerst, C. Arregui Rementeria, M.R. Bartosik, B. Dehning, T. Eisel, M. Sapinski CERN, Geneva, Switzerland V. Eremin, E. Verbitskaya IOFFE, St. Petersburg, Russia C. Fabjan HEPHY, Wien, Austria E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	At the triplet magnets, close to the interaction regions of the LHC, the current Beam Loss Monitoring system is sensitive to the particle showers resulting from the collision of the two beams. For the future, with beams of higher energy and intensity resulting in higher luminosity, distinguishing between these interaction products and possible quench-provoking beam losses from the primary proton beams will be challenging. Investigations are therefore underway to optimise the system by locating the beam loss detectors as close as possible to the superconducting coils of the triplet magnets. This means putting detectors inside the cold mass in superfluid helium at 1.9 K. Previous tests have shown that solid state diamond and silicon detectors as well as liquid helium ionisation chambers are promising candidates. This paper will address the final open question of their radiation resistance for 20 years of nominal LHC operation, by reporting on the results from high irradiation beam tests carried out at CERN in a liquid helium environment.

THPEA047	Diamond Particle Detector Properties during High Fluence Material Damage Tests and their Future Applications for Machine Protection in the LHC	simulation, target, proton, beam-losses	3249
	F. Burkart, J. Blanco, J. Borburgh, B. Dehning, M. Di Castro, E. Griesmayer, A. Lechner, J. Lendaro, F. Loprete, R. Losito, S. Montesano, R. Schmidt, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	Experience with LHC machine protection (MP) during the last three years of operation shows that the MP systems sufficiently protect the LHC against damage in case of failures leading to beam losses with a time constant exceeding 1ms. An unexpected fast beam loss mechanism, called UFOs, was observed, which could potentially quench superconducting magnets. For such fast losses, but also for better understanding of slower losses, an improved understanding of the loss distribution within a bunch train is required. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been developed and successfully tested in the LHC and in experiments to quantify the damage limits of LHC components. This paper will focus on experience gained in use of diamond detectors. The properties of these detectors were measured during high-fluence material damage tests in CERN's HiRadMat facility. The results will be discussed and compared to the cross-calibration with FLUKA simulations. Future applications of these detectors in the LHC to understand beam losses and to improve the protection against fast particle losses will be discussed.

THPEA062	Magnetic Field Measurements for the IAC-RadiaBeam THz Project	dipole, quadrupole, electron, FEL	3282
	P. Buaphad, Y. Kim, M. Williams ISU, Pocatello, Idaho, USA A. Andrews, T. Downer, C.F. Eckman, Y. Kim, M. Smith IAC, Pocatello, IDAHO, USA
	At the Idaho Accelerator Center (IAC) of Idaho State University, recently, a new chicane with four dipoles and quadrupole triplet magnets were installed in a 44 MeV linac to perform the IAC-RadiaBeam Terahertz (THz) project. To generate high power THz radiation, a THz radiator with numerous periodic gratings was also installed downstream of the quadrupole triplet. However, the electron beam shape at the radiator has to be horizontally focused strip-like one due to a tiny radiator gap with a width of 1.2 mm, and electron bunch length should be about a few picosecond (ps) to generate high power THz radiation in the radiator. By using the quadrupole triplet and chicane dipoles, we can control the transverse beam profile and bunch length freely. In this paper, we report the measured field maps of the dipole and quadrupole magnets, their effective lengths, and field strength or gradient as a function of the magnet power supply current.

THPFI011	Thermal Simulations of Charge-exchange Stripper Foils for High-melting-point Materials	stripper, simulation, injection, proton	3312
	Y. Takeda KEK, Ibaraki, Japan M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Charge-exchange stripper foils can be very quickly broken by high-current beams. Hence, a long-lived foil that can withstand prolonged beam irradiation is eagerly awaited. It is well known that the maximum temperature of the foil plays an important role in the foil lifetime. Therefore, the temperature distribution map and the maximum temperature of the foils were investigated in detail by using simulation software of the finite element method and applications with ANSYS. Moreover, the heating properties of several kinds of high-melting-point materials were researched. According to the results, stripper foils of the same effective thickness showed drastically different maximum temperatures, differing by up to about 200 K. From these results, we show that the emissivity and specific heat of the foil considerably influences its maximum temperature.

THPFI020	Radiation Shielding Design for Medical Cyclotrons	shielding, cyclotron, proton, target	3339
	F. Wang, T. Cui, X.L. Jia, Z.G. Li, T.J. Zhang, X.Z. Zhang CIAE, Beijing, People's Republic of China
	With the increasing applications of cyclotrons in health care, a number of cyclotrons ranging from several MeVs to hundreds MeVs have used for radio diagnostic and radiation therapy. A 14 MeV PET cyclotron, CYCIAE-14, has been installed in a shielding building for tests at CIAE that can be used for FDG production and boron neutron capture therapy (BNCT). In the mean time, the development of a 235MeV cyclotron, CYCIAE-235, which can be used for proton therapy, is in progress at the same laboratory. In terms of the cyclotron application in factories and hospitals, an appropriate radiation shielding design is of critical importance. In the case of CYCIAE-14 and CYCIAE-235, the neutron source of different cyclotrons has been estimated to define the thickness of the total shielding, and the concrete is selected as the main shielding material. For CYCIAE-14 specifically, local shielding has been implemented. This paper will give an introduction to the radiation shielding design for CYCIAE-14 and CYCIAE-235 respectively. The typical layout for the application of the two machines is presented in this paper which can be applied in factories and hospitals as well.

THPFI022	The M-C Application in Designing Tailored Cryopump Used in Cyciae-100 Cyclotron	vacuum, cyclotron, beam-losses, ion	3342
	S.P. Zhang, Z.G. Li, G.F. Pan, J.S. Xing, F. Yang, T.J. Zhang CIAE, Beijing, People's Republic of China
	A compact high intensity cyclotron CYCIAE-100 was selected as the driver for the Beijing Radioactive Ion Facility (BRIF). A pressure of 5×10-8 mbar is required to achieve acceptable beam losses in the CYCIAE-100 cyclotron. As the existing ports on the cyclotron valley are insufficient to provide enough pumping speed using commercially available pumps, two tailored cryopanels with a pumping speed of 60000 l/s for each are designed. Based on the Monte-Carlo method, a mathematical model of molecular movement and collision between the panels and their shield was developed. The ratio of molecular reflected to the baffle to molecular passing through the baffle is the sticking probability on the panels. When taking the transmission probability of the chevron baffle, capture coefficient of cryopanel can be calculated. It could provide a reference to design the cryopanel shape and its condensation area.

THPFI025	Design and Experimental Results of an Electro-static Pre-chopper for CSNS LEBT	rfq, power-supply, simulation, cavity	3351
	H.C. Liu, S. Fu, K.Y. Gong, H.F. Ouyang, J. Peng IHEP, Beijing, People's Republic of China
	The China Spallation Neutron Source (CSNS) front end incorporates a pre-chopper in the Low Energy Beam Transport line (LEBT) that will remove a 530ns section of beam at approximately 1MHz rate, which is the RF frequency of the ring at injection. It’s one of the most critical devices for properly controlling the injecting beam loss. Physical designing of the pre-chopper is carried out, and the RFQ itself was used as the beam dump of the chopper system. In order to examine the reliability of the pre-chopper design, the beam study of a similar chopper system was successfully performed. Results of physical design and experiments will be presented.

THPFI029	The Structure Design and Analysis of Proton Beam Window for CSNS	target, proton, scattering, neutron	3361
	H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu IHEP, Beijing, People's Republic of China
	The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). In this paper, a new designed PBW structure called single-double layer structure is discussed. The new structure will be used in CSNS, and it is designed based on the beam characteristic of CSNS, which power is 100 kW. The structure design and thermal-analysis are presented, and the convective coefficient of cooling water is calculated. Besides, the radiation damage is discussed to assure there is no danger of radiation lifetime of PBW.

THPFI032	The Design and Analysis of Proton Beam Window for CSNSIII	scattering, proton, target, neutron	3367
	H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu IHEP, Beijing, People's Republic of China
	The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). When the beam power of CSNS upgrades from 100kw to 500kw (CSNSIII), the present single-double layer structure of PBW cannot meet the demands. The PBW will be changed to other structure. This paper discusses sandwiched structure and multiple pipe structure, and the later one is chosen as the PBW of CSNSIII. An appropriate convective coefficient of cooling water is chosen, based on which the detailed thermal-stress analysis is presented. Besides, the lifetime is estimated. All these analyses show the designed PBW can work well in CSNSIII.

THPFI040	DEVELOPMENT OF A TARGET SYSTEM FOR RARE ISOTOPE BEAM PRODUCTION WITH HIGH-POWER HEAVY-ION BEAMS*	target, electron, ion, vacuum	3373
	J.-W. Kim, S. Hong, J.H. Kim, M. Kim, J. Song IBS, Daejeon, Republic of Korea
	To produce rare isotope beams, in-flight fragmentation method utilizing a thin target and heavy-ion primary beam can be used. The existing facilities provide the maximum primary beam power of a few kW, while the next generation facility is planned to use hundreds of kW of 238U beam. We are designing a rare-isotope beam facility, which can provide U beam with the maximal power of 400 kW at the energy of 200 MeV/u. The high-power target studied is made of multi-slice rotating graphite to enhance radiation cooling. The total target thickness is roughly 2 mm with more than 10 slices. The resultant power density inside the target reaches above 50 MV/cm³. Numerical simulation for thermo-mechanical analysis has been performed using PHITS and ANSYS for single and multi-slice targets. Also, empirical test was made using 70-keV electron beam for a single-slice rotation target with the thickness of 0.2 mm. The results of simulation and e-beam tests will be presented. * Work supported by Rare Isotope Science Program (RISP) through the National Research Foundation of Korea (NRF) funded by Ministry of Science, ICT and Future Planning (MSIP) (2011-0032011)

THPFI042	Design Considerations for Phase Reference Distribution System at ESS	linac, controls, LLRF, cavity	3379
	R. Zeng ESS, Lund, Sweden A.J. Johansson Lund University, Lund, Sweden
	PRDS (Phase Reference Distribution System) will be serving as the phase alignment line for all cavities with high phase stability. With the current design of individually RF source powering for most cavities at ESS, phase reference distribution system should provide the reference signals for totally 34 LLRF systems at 100 meters long low-frequency section (for all 352.21MHz cavities, including RFQ, DTL, bunching cavities and spokes), and for totally 180 LLRF systems at 342 meters long high-frequency section (for all 704.42MHz cavities, including medium beta and high beta elliptical cavities). Coaxial cable based solution and optical fibre based solution are discussed in this note for PRDS (Phase reference distribution system) at ESS. Some possible schemes in each of these two distribution solutions are introduced and comparisons among these schemes are made. Some effort is made as well to find out a reasonable design for PRDS at ESS.

THPFI047	Design Guidelines for Ferrite Absorbers Submitted to RF-induced Heating	damping, HOM, pick-up, FEL	3394
	A. Bertarelli, M. Garlaschè CERN, Geneva, Switzerland
	The use of ferrite absorbers is one of the most effective means of damping potentially harmful high order RF modes, which may lead to beam instabilities and excessive power losses in accelerator devices. However, the power deposited on ferrite absorbers themselves may lead to ferrite exceeding its Curie temperature, losing its damping properties. An evaluation of the ferrite capability to dissipate deposited heat is hence of paramount importance for the safe design of particle accelerator devices. In this paper, figures of merit are proposed to assess the maximum specific power allowed on a generic ferrite tile, before it reaches its Curie temperature. Due to its inherent brittleness, sufficient contact pressure between ferrite and its housing, allowing heat transmission by conduction, can hardly be applied. A semi-analytical study is thus performed, assuming that ferrite is evacuating heat solely through radiation. The described method is then exemplified in the case of the BPM-embedded tertiary collimator (TCTP) designed in the framework of the LHC collimation upgrade.

THPFI050	Some Ideas Towards Energy Optimization at CERN	vacuum, proton, controls, secondary-beams	3400
	H.J. Burckhart, J.-P. Burnet, F. Caspers, V. Doré, L. Gatignon, C. Martel, M. Nonis, D. Tommasini CERN, Geneva, Switzerland
	The paper presents the efforts of CERN to optimize its energy usage. Work is proceeding in 3 areas: accelerators, campus and infrastructure, and re-use of thermal “waste” energy. The accelerator chain has the potential to further reduce the energy consumption by dynamic suppression of cycles when they are temporarily not needed and by operating magnets in pulsed mode. R&D for future accelerators includes the recuperation of the RF energy, which is not used for acceleration of the beams. Concerning the CERN campus more than half of the buildings are older than 40 years. Hence there is a big need for renovation, which includes energy aspects. New buildings use renewable energy whenever possible. As an example a building is under construction, which will use a 250 m2 solar field together with an absorption refrigerator for cooling purposes. Finally, about 80% of the electric energy gets dissipated in air cooling towers. Part of this energy can be re-used for heating buildings.

THPFI055	First Year of Operations in the HiRadMat Irradiation Facility at CERN	proton, target, laser, instrumentation	3415
	A. Fabich, N. Charitonidis, N. Conan, K. Cornelis, D. DePaoli, I. Efthymiopoulos, S. Evrard, H. Gaillard, J.L. Grenard, M. Lazzaroni, A. Pardons, Y.D.R. Seraphin, C. Theis, K. Weiss CERN, Geneva, Switzerland N. Charitonidis EPFL, Lausanne, Switzerland
	HiRadMat (High Irradiation to Materials) is a new facility at CERN constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of 7.2 μs, to maximum pulse energy of 3.4MJ. For 2012, the first year of operations of the facility, nine experiments were scheduled and completed data-taking successfully. The experience gained in operating this unique facility, along with highlights of the experiments and the instrumentation developed for online measurements are reported.

Paper

Title

Other Keywords

Page

MOYCB101

Brightness and Coherence of Synchrotron Radiation and FELs

brightness, FEL, electron, undulator

16

Z. Huang
SLAC, Menlo Park, California, USA

Essential properties of radiation from storage rings and FELs include spatial- and temporal beam brightness and coherence. Starting from a fundamental representation of the electron beam as a radiating source the electromagnetic power can be represented as modes in phase-space to characterize beam quality. For storage rings, conditions for transverse coherence are possible which can lead to high-resolution imaging under a variety of polarization conditions. For FELs the radiation brightness is over 10 orders of magnitude higher with finite temporal coherence times and much of the total FEL power contained in the dominant mode. This presentation should provide an overview of the above.

Slides MOYCB101 [9.731 MB]

MOZB102

Undulator Technologies for Future Free Electron Laser Facilities and Storage Rings

undulator, vacuum, electron, wiggler

26

M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France

Insertion devices (undulators and wigglers) are key components for high brightness third generation synchrotron sources and for the amplifying medium of free electron lasers. Different technological developments carried out worldwide lead to improved undulator performance. In particular, the advances concerning the in vacuum permanent magnet systems, in particular for short period ones with the operation at cryogenic temperature with NdFeB or PrFeB magnets or for long period ones where in vacuum wigglers will be described. Secondly, progress in Elliptical Polarised Undulators (EPU) will be discussed, such as the DELTA undulator. Recent progress in superconducting undulators will also be reported. Finally, the effect of the insertion devices on the light source operation is analysed, either with the strategies to compensate unwanted effects or in viewing taking advantage of them as for Robinson or damping wigglers for reducing storage ring horizontal emittance.

Slides MOZB102 [8.940 MB]

MOZB202

The First Long Shutdown (LS1) for the LHC

dipole, ion, luminosity, vacuum

44

F. Bordry, S. Baird, K. Foraz, A.-L. Perrot, R.I. Saban, J.Ph. G. L. Tock
CERN, Geneva, Switzerland

The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections so as to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. LS1 will see a massive programme of maintenance for the LHC and its injectors in the wake of more than three years of operation without the long winter shutdowns that were the norm in the past. The main driving effort will be the consolidation of the 10,170 high-current splices between the superconducting magnets. The presentation describes first the preparation phase with the prioritisation of the activities, the building of the teams and the detailed planning of the operation. Then, it gives the status after 3 months and the restart plans for all CERN accelerators. First lessons learnt for the 2nd long shutdown (LS2) will conclude the presentation.

Slides MOZB202 [13.675 MB]

MOPEA010

Transfer of RIB’s between ISOL Target and Experiment Hall at SPIRAL 2

target, ion, remote-handling, ISOL

85

F.R. Osswald, T. Adam, E. Bouquerel, D. Boutin, A. Dinkov, M. Rousseau, A. Sellam
IPHC, Strasbourg Cedex 2, France
N.Yu. Kazarinov
JINR, Dubna, Moscow Region, Russia
H. Weick, M. Winkler
GSI, Darmstadt, Germany

Funding: The authors would like to acknowledge the German-French and Russian-French agreements enabling the allocation of resources : IN2P3 - GSI (id. 12-69), and IN2P3 - JINR (id. 11-88) collaborations.
The production of intense radioactive beams requires a high power target, an efficient beam selection and transport, safe operations and a reliable-cost effective facility. The SPIRAL 2 project a so called second generation RIB facility is under construction at GANIL. The low energy RIB’s will be produced by neutron induced fissions obtained from a 40 MeV primary beam (deutons) and a graphit convertor. Several issues must be addressed in order to insure the safety rules and ultimately the performances requested by the scientific programme. Among them, the space charge dominated regime during the extraction of the beam after the target and the ion source, the compromise between beam transmission, rejection of the light-ion beam, and management of the main safety features. Most of the investigations currently in progress are devoted to the nuclear engineering, the maintenance and the multi-scale integration of the segmented beam line with the infrastructure.
* RIB dynamics of the SPIRAL 2 Transfer Line, HIAT 2012
** Simulation of Hollow Beam formation at SPIRAL 2, IPAC 2011
*** A Secondary Radioactive Beam Line Section for SPIRAL 2, HIAT 2009

MOPEA014

Temporal and Spectral Observation of Laser-induced THz Radiation at DELTA

electron, laser, storage-ring, simulation

94

P. Ungelenk, H. Huck, M. Huck, M. Höner, S. Khan, R. Molo, A. Schick
DELTA, Dortmund, Germany
N. Hiller, V. Judin
KIT, Karlsruhe, Germany

Funding: Work supported by the DFG, the BMBF, the Federal State NRW, the Initiative and Networking Fund of the Helmholtz Association, and the German Federal Ministry of Education and Research.
Coherent THz pulses caused by a laser-induced density modulation of the electron bunches are routinely produced and observed at DELTA, a 1.5 GeV synchrotron light source operated by the TU Dortmund University. New measurements performed with a fast hot-electron bolometer allow insight into the turn-by-turn evolution of these pulses. Furthermore, first results from a Fourier transform infrared spectrometer, which is currently under commissioning, are presented.

MOPEA019

Studies of Bunch-bunch Interactions in the ANKA Storage Ring with Coherent Synchrotron Radiation using an Ultra-fast Terahertz Detection System

synchrotron, storage-ring, wakefield, synchrotron-radiation

109

A.-S. Müller, B.M. Balzer, C.M. Caselle, N. Hiller, M. Hofherr, K.S. Ilin, V. Judin, B. Kehrer, S. Marsching, S. Naknaimueang, M.J. Nasse, J. Raasch, A. Scheuring, M. Schuh, M. Schwarz, M. Siegel, N.J. Smale, J.L. Steinmann, P. Thoma, M. Weber, S. Wuensch
KIT, Karlsruhe, Germany

Funding: Supported by Initiative and Networking Fund of the Helmholtz Association under contract No. VH-NG-320 and German Federal Ministry of Education and Research under Grant. Noss. 05K10VKC and 05K2010VKD
In the low-alpha operation mode of the ANKA synchrotron light source, coherent synchrotron radiation (CSR) is emitted from short electron bunches. Depending on the bunch current, the radiation shows bursts of high intensity. These bursts of high intensity THz radiation display a time evolution which can be observed only on long time scales with respect to the revolution period. In addition, long range wake fields can introduce a correlation between the bunches within a bunch train and thus modify the observed behavior. A novel detection system consisting of an ultra-fast superconducting THz detector and data acquisition system was used to investigate correlations visible on the bursting pattern and to study the interactions of very short pulses in the ANKA storage ring.

MOPEA020

Comparison of Different Approaches to Determine the Bursting Threshold at ANKA

synchrotron, storage-ring, electron, synchrotron-radiation

112

P. Schönfeldt, N. Hiller, V. Judin, A.-S. Müller, M. Schwarz, J.L. Steinmann
KIT, Karlsruhe, Germany

The synchrotron light source ANKA at the Karlsruhe Institute of Technology provides a dedicated low-α-optics. In this mode bursting of Coherent Synchrotron Radiation (CSR) is observed for bunch charges above a threshold that depends on beam parameters. This threshold can be determined by several approaches, e.g. bunch lengthening or changes in the THz radiation spectra. This paper compares different methods and their implementation at the ANKA storage ring outlining their advantages, disadvantages and limitations, including reliability and possibility of real time analysis.

MOPEA024

Effects of Insertion Devices in the High Field Lattice Structure of ILSF Storage Ring

dynamic-aperture, insertion, insertion-device, quadrupole

124

F. Saeidi, E. Ahmadi, H. Ghasem
ILSF, Tehran, Iran
H. Ghasem
IPM, Tehran, Iran

We have studied effects of different insertion devices(IDs) in the high filed ILSF storage ring. Radiation from the IDs leads to change emittance and energy spread of the ring and magnetic field of them results to beta-beating, tune shift and shrink of dynamic aperture. This paper describes effects of the IDs on beam parameters of the high field lattice structure of ILSF storage ring and proposes the compensation method of these effects.
farhad.saeidi@ipm.ir

MOPEA038

Coherent Wiggler Radiation of Picosecond CW Electron Beam Produced by DC-SRF Photoinjector

wiggler, electron, SRF, acceleration

160

S. Huang, J.E. Chen, S. Chen, K.X. Liu, S.W. Quan, Zh.W. Wang, X.D. Wen, F. Zhu
PKU, Beijing, People's Republic of China

The DC-SRF photoinjector at Peking University is capable of providing CW electron beam with the energy of 3-5 MeV. The beam has high repetition rate, picosecond bunch length and high quality, which can be used to produce high repetition rate THz wave by wiggler radiation. Through off-crest acceleration, electron beam from the injector may be bunched, which will lead to coherent enhancement of the radiation power. With current setup of the DC-SRF injector and a 10-period wiggler, THz radiation power of 10s mW to a few watts can be achieved within the wavelength range of 200 μm to 500 μm. In this work, we will present the calculation results about THz radiation produced by the electron beam from DC-SRF photoinjector. The preparation for the experiments will be also described.

MOPEA044

Maintenance Experience for Personnel Safety System at SSRF

controls, PLC, synchrotron, synchrotron-radiation

175

J.J. Lu, P. Fei, G. Wang, X. Xia, J.Q. Xu, X.J. Xu
SINAP, Shanghai, People's Republic of China

To improve reliability and reduce faults of Personal Safety System (PSS) at Shanghai Synchrotron Radiation Facility (SSRF), two types of system maintenances were carried out since SSRF completion in 2009. The maintenances include maintenance during machine operation and that during shutdown period. The failures of the PSS are summarized for last 3 years operation, and the causes of these failures are analyzed. Main failures were occurred in the access control system and UPS power-supply mode during last 3 years operation. To treat these failures, detail maintenance plan and system upgrading schemes were carried out. After the maintenance and system upgrading, the numbers of beam shutdown which caused directly by the PSS failures are obviously reduced. It was 4 times beam shutdown in 2009 and 0 in 2011.

MOPEA058

CNGS, CERN Neutrinos to Gran Sasso, Five Years of Running a 500 Kilowatt Neutrino Beam Facility at CERN

target, proton, extraction, kaon

211

E. Gschwendtner, K. Cornelis, I. Efthymiopoulos, A. Pardons, H. Vincke, J. Wenninger
CERN, Geneva, Switzerland
I. Krätschmer
HEPHY, Wien, Austria

The CNGS facility (CERN Neutrinos to Gran Sasso) aims at directly detecting muon to tau neutrino oscillations where an intense muon-neutrino beam (10¹⁷ muon-neutrinos/day) is generated at CERN and directed over 732km towards the Gran Sasso National Laboratory, LNGS, in Italy, where two large and complex detectors, OPERA and ICARUS, are located. The CNGS facility (CNGS Neutrinos to Gran Sasso) started with the physics program in 2008 and delivered until the end of the physics run 2012 more than 80% of the approved protons on target (22.5·10¹⁹ pot). An overview of the performance and experience gained in operating this 500kW neutrino beam facility is described. Major events since the commissioning of the facility in 2006 are summarized. Highlights on the CNGS beam performance are given.

MOPFI017

SuperKEKB Positron Source Target Protection Scheme

target, positron, electron, simulation

315

L. Zang, T. Kamitani
KEK, Ibaraki, Japan

The SuperKEKB requires an intense beam with a large number of positrons, which is generated by a high energy electron beam strike on a solid tungsten target. The cascade shower in the target deposits large amount of energy in the material leading to target damage. The pulsed electron beam distributed the energy non-uniformly over the target. In that case, a mechanical stress appears due to the large thermal gradient during each pulse, which could potentially destroy the target. Based on the analysis of the SLAC damaged target, peak energy deposition density (PEDD) should not exceed 35 J/g to ensure a long term of safe operation. One way of reducing PEDD is increasing the beam spot size. Hence we proposed a target protection scheme, in which a protection target is placed upstream of generation target as a spoiler. The aim is to maintain the generation target’s PEDD below 35 J/g even with a point primary electron beam. In this paper, we will introduce graphite, aluminum and copper as the protection target material candidates. And also present the PEDD and positron yield evaluation as a function of various parameters such as protection target thickness and drift space.

MOPFI024

Ultra-short Electron Bunch Generation by an ECC RF Gun

gun, electron, laser, cathode

330

Y. Koshiba, T. Aoki, M. Mizugaki, K. Sakaue, M. Washio
Waseda University, Tokyo, Japan
T. Takatomi, J. Urakawa
KEK, Ibaraki, Japan

Funding: Work supported by JSPS Grant-in-Aid for Young Scientists (B) 23740203 and Scientific Research (A) 10001690
Energy Chirping Cell attached rf gun (ECC rf gun) is a photocathode rf gun specialized for ultra-short bunch generation. This ECC rf gun has been made with the collaboration of High Energy Accelerator Research Organization (KEK). Although the bunch length could be controlled by the laser pulse width, the bunch length ends up to be more than 1ps due to space charge effect when using a femto-second laser and a normal 1.6 cell cavity. Concerning this phenomenon, ECC is attached right after the 1.6 cell so that the electron bunch would be compressed after the electron bunch is accelerated around 5MeV. The roll of ECC is to chirp the energy with the linear part of the rf electric field. The electron bunch would be compressed by velocity difference as it drifts. Simulation results from PARMELA and GPT show that ECC rf gun can accelerate an 100pC bunch with the bunch length less than 100fs. We already manufactured this ECC rf gun and installed in our system. We demonstrated the ultra-short bunch by measuring the coherent THz light by synchrotron radiation and transition radiation. In this conference, we will report the results of ultra-short bunch generation experiments, and future plans.

MOPFI026

Thermal Simulations of a New Target Configuration for Production of Radioactive Nuclide

target, neutron, simulation, ion

336

L.H. Chen, B.Q. Cui, Q.H. Huang, W. Jiang, R. Ma, Y.J. Ma, B. Tang
CIAE, Beijing, People's Republic of China

China Advanced Rare Ion-beam Facility (CARIF) based on China Advanced Research Reactor (CARR) has been proposed in order exploring the frontier of nuclear physics. A target with 5 g 235U is proposed in the project. The thermal neutron fission of 235U will produce radioactive nuclei and the great thermal load (~50 kW). The target of CARIF needs endure high temperature and thermal energy deposit. A new multi-targets configuration is proposed. It consists of several discrete targets instead of traditional single-target structure used in accelerator driven facility. Because there is more thermal radiation area in this configuration, thermal radiation capacity is enhanced, so the target can withstand higher thermal power. The temperature distribution of multi-targets was simulated with finite element code. The results show that the configuration of multi targets can effectively reduce the target temperature. From the perspective of target temperature distribution, the configuration could endure 50kW thermal deposit. It's possible to use 5 g 235U in CARIF for production of radioactive nuclide.

MOPFI038

Generation and Measurement of Sub-picosecond Electron Bunch in Photocathode RF Gun

laser, electron, emittance, acceleration

372

W.W. Li, Z.G. He, R. Huang, Q.K. Jia, G. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

The generation of subpicosecond electron bunch in the photocathode rf gun was considered and simulated by improving the acceleration gradient of the gun, suitably tuning the charge of the electron bunch and the acceleration phase. To measure the length of the electron bunch, the design of a nondestructive bunch length measurement technology was also presented in this paper.

MOPFI039

The Design of a Compact THz Source Based on Photocathode RF Gun

electron, gun, emittance, space-charge

375

W.W. Li, Z.G. He, R. Huang, Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

Narrow-band THz coherent Cherenkov radiation can be driven by a subpicosecond electron bunch traveling along the axis of a hollow cylindrical dielectric-lined waveguide. We present a scheme of compact THz radiation source based on the photocathode rf gun. On the basis of our analytic result, the subpicosecond electron bunch with high charge (800pC) can be generated directly in the photocathode rf gun. A narrow emission spectrum peaked at 0.24 THz with 2 megawatt (MW) peak power is expected to gain in the proposed scheme (the length of the facility is about 1.2 m), according to the analytical and simulated results.

MOPFI070

Spallation is not the only Fruit: Low Energy Fusion as a Source of Neutrons

neutron, target, proton, simulation

443

S.C.P. Albright, R. Seviour
University of Huddersfield, Huddersfield, United Kingdom

Commercially there is a growing interest in applications of neutrons. Currently the majority of neutron sources are based at research institutions from either reactors or spallation sources. Smaller portable sources contain either fissile isotope or sealed fusors are available, although they either use or produce tritium, or other long lived decay products. As an alternative to the large facilities and the radio-toxicology of current portable sources research is being performed with an aim to produce a fusion based neutron source with neither of these concerns. We show that MCNPX is able to accurately reproduce (p,n) reactions for a number of light elements. Simulations of low energy proton reactions with light nuclei simulated with MCNPX and Geant4 are compared with experiment.

MOPME010

Transverse Beam Profile Diagnostics using Point Spread Function Dominated Imaging with Dedicated De-focusing

electron, target, background, focusing

488

G. Kube, S. Bajt
DESY, Hamburg, Germany
W. Lauth
IKP, Mainz, Germany
Yu.A. Popov, A. Potylitsyn, L.G. Sukhikh
TPU, Tomsk, Russia

Transverse beam profile diagnostics in electron accelerators is usually based on direct imaging of a beam spot via optical radiation (transition or synchrotron radiation). In this case the fundamental resolution limit is determined by radiation diffraction in the optical system. A method to achieve resolutions beyond the diffraction limit is to perform point spread function (PSF) dominated imaging, i.e. the recorded image is dominated by the resolution function of a point source (single electron), and with knowledge of the PSF the true image (beam spot) may be reconstructed. To overcome the limited dynamical range of PSF dominated imaging, a dedicated de-focusing of the optical system can be introduced. In order to verify the applicability of this method, a proof-of-principle experiment has been performed at the Mainz Microtron MAMI (University of Mainz, Germany) using optical transition radiation. Status and results of this experiment will be presented.

MOPME011

Investigation of the Applicability of Parametric X-ray Radiation for Transverse Beam Profile Diagnostics

photon, diagnostics, electron, background

491

G. Kube, C. Behrens
DESY, Hamburg, Germany
A.S. Gogolev, Yu.A. Popov, A. Potylitsyn
TPU, Tomsk, Russia
W. Lauth
IKP, Mainz, Germany
S. Weisse
DESY Zeuthen, Zeuthen, Germany

Transverse beam profile diagnostics in electron linacs is widely based on optical transition radiation (OTR) as standard technique which is observed in backward direction when a charged particle beam crosses the boundary between two media with different dielectric properties. The experience from modern linac based light sources like LCLS or FLASH shows that OTR diagnostics might fail because of coherence effects in the OTR emission process. A possibility to overcome this limitation is to measure at much shorter wavelengths, i.e. in the X-ray region, using parametric X-ray radiation (PXR) which additionally offers the advantage to be generated at crystal planes oriented under a certain angle to the crystal surface, thus allowing a spatial separation from a possible COTR background *. A first test experiment has been performed at the Mainz Microtron MAMI (University of Mainz, Germany) in order to study the applicability of PXR for beam diagnostics, and the status of this experiment will be presented.
* A. Gogolev, A. Potylitsyn, G. Kube, Journal of Physics 357 (2012) 012018

MOPME049

Status of Non-destructive Bunch Length Measurement based on Coherent Cherenkov Radiation

electron, target, diagnostics, vacuum

583

H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang
SINAP, Shanghai, People's Republic of China
G.A. Naumenko, A. Potylitsyn, M.V. Shevelev, D.A. Shkitov
TPU, Tomsk, Russia

Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the Chinese NSFC 11175240.
As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented.
* Shevelev M. et al., Journal of Physics: Conf. Ser. 357 (2012) 012023.

MOPME053

Point Spread Function Study of X-ray Pinhole Camera in SSRF

synchrotron, synchrotron-radiation, emittance, storage-ring

592

Z.C. Chen, J. Chen, G.Q. Huang, Y.B. Leng
SSRF, Shanghai, People's Republic of China

Funding: Supported by National Natural Science Foundation of China (11075198)
An X-ray Pinhole Camera that has been used to present the transverse beam size with an intuitive grasp of the distribution of the beam radiation was installed on one beam-line of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). The real beam size however is a function of the image size of the CCD camera and the point spread function (PSF) of the system. The PSF was calculated but poorly tested. This article will present the measurement of the PSF with a series of beam based experiments and the consistency with the theoretical beam size.

MOPME060

Introduction to Beam Diagnostics Components for PAL-ITF

electron, diagnostics, laser, gun

610

H. J. Choi, M.S. Chae, J.H. Hong, C. Kim, D.T. Kim, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) is building the 4th generation X-ray free electron laser (XFEL). The Injection Test Facility (ITF) is a test facility established to improve the functions of the laser gun and pre-injector to be installed in XFEL. To improve the effects of ITF, two factors are required. The first is to be able to generate low-emittance electron beams stably at the laser gun, and the second is to control increasing emittance by space charge effect by accelerating electron beams with high energy at the pre-injector. In this way, high-quality electron beams can be materialized. Various beam diagnostics are installed in the accelerator system for beam diagnostics and measurements. Five kinds of beam diagnostics were installed in the PAL-ITF. These are (1) ICT and (2) Faraday Cup to measure current and electrons charge, (3) Stripline BPM to measure the location of beams, (4) a YAG/OTR Screen Monitor to measure beam energy and transverse profile motion and (5) a Wire Scanner to measure beam size. In this paper, the purposes and properties of each diagnostic unit and measurement results are introduced.

MOPME061

Femtosecond e-bunch Length Measurement at fs-THz Accelerator at PAL

electron, linac, laser, gun

613

J.H. Ko, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea

Longitudinal distribution of femto-second electron beam has been evaluated by the coherent transition radiation Michelson interferometer with the reconstruction procedure from interferograms. We measure the bunch length of the Thz Accelerator using interferogram method in Pohang Accelerator Lab and compare with the energy of transition radiation and bunch length.

MOPME062

UV and X-ray Diffraction Radiation for Submicron Noninvasive Diagnostics

diagnostics, target, polarization, electron

616

D.Yu. Sergeeva, M.N. Strikhanov, A.A. Tishchenko
MEPhI, Moscow, Russia

Funding: This work was partially supported by Russian Ministry of Education and Science (State contract 12.527.12.5002).
Diffraction radiation (DR) arises when a charged particle moves near a target. The theory of X-ray DR from single particles was created in [*, **], and recently the theory has been developed for bunches [***]. DR from relativistic particles is used for noninvasive bunch diagnostics and also for creating new and effective sources of radiation, including Free-electron laser based on the Smith-Purcell effect. In the present work we explore theoretically DR from the bunch of ultrarelativistic charged particles at X-ray and UV frequencies domains. It is shown that incoherent part of form-factor, describing the effect of N electrons in bunch, exists and differs from the unity. The coherent part of radiation depends on transversal size of the bunch as ratio of the Bessel function to its argument. The coherence effects are proved to be important up to the wavelengths much less than transversal size of the bunch. The results obtained open the possibility to diagnose bunches of the submicron size with very high accuracy.
* A.A. Tishchenko et al, PLA. 359 (2006) 509.
** A.P. Potylitsyn et al, Diffraction radiation from relativistic particles, Springer, 2010
*** D.Yu. Sergeeva et al, Proc. Channeling-2012, p.52, 2012

MOPME063

Backward X-ray Transition Radiation from Multilayered Target for Submicron Beam Diagnostics

target, diagnostics, polarization, electron

619

A.A. Tishchenko, D.Yu. Sergeeva, M.N. Strikhanov
MEPhI, Moscow, Russia
K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom

Funding: This work was partially supported by Russian Ministry of Education and Science (State contract 12.527.12.5002).
Backward transition radiation (TR) is a TR arising in the direction of mirror reflection relative to the charged particles trajectory. Therefore for oblique incidence it can be emitted under big angles which is useful from point of view of measuring of the radiation. In spite of the fact that backward TR in X-ray frequency domain is much weaker than forward TR [*], it has recently been proposed by A.P. Potylitsyn and others [**] as an instrument for submicron electron beam diagnostics. In this work we propose to use the multilayered target in order to enhance the resulting radiation, i.e. to use resonant backward X-ray TR. So far X-ray TR has not been explored theoretically for backward geometry. It is shown that the expressions obtained coincide in special case of forward resonant X-ray TR with the results by L. Durand (***) and X. Artru (****). We explore the spectral and angular characteristics of resonant backward X-ray TR form point of view of submicron beam diagnostics for the ultrarelativistic charged particles bunches. The role of absorption in the target material and also the coherent and incoherent parts of the radiation is analyzed
* A.A. Tishchenko et al, NIMB 227 (2005) 63.
** L.G. Sukhikh et al, J of Phys: Conf. Ser. 236 (2010) 012011.
*** L. Durand, Phys Rev D11 (1975) 89.
**** X. Artru et al, Phys Rev D12 (1975) 1289.

MOPME064

SLM and Flags for Booster of NSLS-II

booster, vacuum, synchrotron, synchrotron-radiation

622

O.I. Meshkov, V. Smalyuk
BINP SB RAS, Novosibirsk, Russia
V.L. Dorokhov
BINP, Novosibirsk, Russia

Set of diagnostics of booster of NSLS-II includes 6 fluorescent screens (flags) and 2 synchrotron light monitors (SLM). The flags will be applied during booster commissioning for closing of the beam turn. They are also a useful tool in case of malfunction elimination. SLM will be used both for booster comissioning and for operation. The details of calibration and design of the devices are discussed.

MOPME065

Approximate Method of Calculation of a Bunch Radiation in Presence of Complex Dielectric Object

vacuum, optics, diagnostics, scattering

625

A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin
Saint-Petersburg State University, Russia

Funding: Work supported by the Grant of President of Russian Federation, Russian Foundation for Basic Research, and the Dmitry Zimin "Dynasty" Foundation.
Cherenkov radiation is widely used for detection of charged particles and can be also applied for particle bunch diagnostics*. As a rule, dielectric objects applied for these goals have complex forms. Therefore development of methods of calculation of bunch radiation in presence of complex dielectric objects is now of a great interest. The approximate method developed by us allows to take into account influence of the object boundaries closed to the charge trajectory as well as "external" boundaries of the object. The case of the charge crossing a dielectric plate was considered as a test problem. The exact solution of this problem is in a good agreement with our approximate solution. Next, the cases of more complex objects were analyzed. One of them is a dielectric cone with a vacuum channel. Particularly, it was shown that radiation can be convergent under certain conditions, that is the field outside the cone can be more intensive than on the cone boundary. Radiation of the bunch in the case of dielectric prism was considered as well.
* A.P. Potylitsyn, Yu.A. Popov, L.G. Sukhikh, G.A. Naumenko, M.V. Shevelev, Journal of Physics: Conference Series 236 (2010) 012025.

MOPME066

Radiation of a Charged Particle Bunch Moving along Boundary of Wire Metamaterial

vacuum, diagnostics, lattice, optics

628

A.V. Tyukhtin, S.N. Galyamin, V.V. Vorobev
Saint-Petersburg State University, Russia

Funding: Work supported by Russian Foundation for Basic Research and the Dmitry Zimin “Dynasty” Foundation.
The material under consideration represents a periodical volume structure of long parallel conductive wires. If wavelengths are much greater than periods, the structure can be described as some anisotropic medium possessing both frequency and spatial dispersion* (so-called wire metamaterial). Earlier we considered the radiation of bunches moving in boundless wire metamaterial. It has been discovered that this radiation is nondivergent, and it is perspective for diagnostics of bunches**. Now we consider the case when the bunch moves in vacuum along the boundary of the semi-infinite metamaterial perpendicularly to the wires. Analytical and numerical analysis of the problem is performed. It is shown that radiation from a point charge concentrates in some vicinity of certain planes and propagates along the wires with speed of light. Series of computations show that the radiation under consideration can be useful for determination of sizes and shape of bunch.
*A.V. Tyukhtin, E.G. Doilnitsina, J. Phys. D - Appl. Phys., 44, 265401 (2011).
**V.V. Vorobev, A.V. Tyukhtin, Phys. Rev. Lett., 108, 184801 (2012).

MOPME067

Non-Invasive Bunch Length Diagnostics Based on Interferometry From Double Diffraction Radiation Target

target, electron, diagnostics, FEL

631

D.A. Shkitov, G.A. Naumenko, A. Potylitsyn, M.V. Shevelev
TPU, Tomsk, Russia
H.X. Deng, S.L. Lu, T. Yu, J.B. Zhang
SINAP, Shanghai, People's Republic of China

Funding: This work was supported by the joint Russian-Chinese grant (RFBR 110291177 and NSFC 11111120065) and partially by the Program of Russian MES “Nauka” and the SINAP Xinrui Program Y15501A061.
Reliable and precise non-invasive beam diagnostics technique to measure length of sub-picosecond electron bunches are required for new accelerator facilities (FEL, et al.). Investigations of coherent radiation generated by such bunches using different interferometers allow to determine a bunch length*. Measuring a dependence of radiation yield intensity from two DR targets on a distance between them (the intrinsic DR interferogram), it is possible to obtain the same information. Such a non-invasive technique can be directly used for ultra-short bunch length measurements. Recently the first experiment with a double DR target was carried out at the SINAP fs linac facility** with parameters described in***. The double DR target was consisted of two plates made from Al foil. The pyro-electric detector SPI-D-62 was used. Here we report the results of the second stage of our investigations. The DR interferograms of different electron bunch length were measured. The bunch length was reconstructed using the heuristic model based on the dimension theory and simulation data. We compare the results from DR interferograms and Michelson interferometer measurements and show their similarity.
*Murokh A. et al., NIMA 410 (1998) 452.
**Zhang J.B., Shkitov D.A. et al., IBIC’12 MOPB65 (2012).
***Lin X., Zhang J. et al., Chin. Phys. Let. V. 27 N. 4 (2010) 044101.

MOPME068

Feasibility Study of a 2nd Generation Smith-Purcell Radiation Monitor for the ESTB at SLAC

simulation, background, electron, vacuum

634

N. Fuster Martinez, A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain
H.L. Andrews
LANL, Los Alamos, New Mexico, USA
F. Bakkali Taheri, R. Bartolini, G. Doucas, I.V. Konoplev, C. Perry, A. Reichold, S.R. Stevenson
JAI, Oxford, United Kingdom
J. Barros, N. Delerue, M. Grosjean
LAL, Orsay, France
V. Bharadwaj, C.I. Clarke
SLAC, Menlo Park, California, USA

The use of a radiative process such as the Coherent Smith-Purcell Radiation (CSPR) is a very promising non-invasive technique for the reconstruction of the time profile of relativistic electron bunches. Currently existing CSPR monitors do not have yet single-shot capability. Here we study the feasibility of using a CSPR based monitor for bunch length measurement at the End Station Test Beam (ESTB) at SLAC. The aim is to design a second-generation device with single-shot capability, and use it as a diagnostic tool at ESTB. Simulations of the spectral CSPR energy distribution and feasibility study have been performed for the optimization of the parameters and design of such a device.

MOPME071

Characterisation of Si Detectors for use at 2 Kelvin

proton, cryogenics, luminosity, superconducting-magnet

643

M.R. Bartosik, C. Arregui Rementeria, B. Dehning, T. Eisel, C. Kurfuerst, M. Sapinski
CERN, Geneva, Switzerland
V. Eremin, E. Verbitskaya
IOFFE, St. Petersburg, Russia

Funding: This research project has been supported by a Marie Curie Early Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract nr PITN-GA-2011-289485-OPAC.
It is expected that the luminosity of the Large Hadron Collider (LHC) will be bounded in the future by the beam loss limits of the superconducting magnets. To protect the superconducting magnets of the high luminosity insertions an optimal detection of the energy deposition by the shower of beam particles is necessary. Therefore beam Loss Monitors (BLM) need to be placed close to the particle impact location in the cold mass of the magnets where they should operate in superfluid helium at 1.9 Kelvin. To choose optimal detectors n-type silicon wafers have been examined at superfluid helium temperature whilst under irradiation from a high intensity proton beam. The radiation hardness and leakage current of these detectors were found to be significantly improved at 1.9 Kelvin when compared to their operation at room temperature.

MOPWA003

New Development of Compact Fast Pulsed Power Supply System in the SPring-8

power-supply, kicker, high-voltage, pulsed-power

666

C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan
T. Ohshima
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.

MOPWA021

Design of the Air Cooling System for the High Voltage Power Supply of a Electron Accelerator

power-supply, high-voltage, simulation, electron

705

F. Zhong, X. Lei, J. Yang, L. Yang
HUST, Wuhan, People's Republic of China

High voltage electron accelerators are widely applied in many fields of radiation pro-cessing,and the high voltage power supply is the critical equipment for the accelerator. for the requirement of high voltage, the design of locate the power supply in a steel barrel filled with SF6 is commonly used. Considering the various losses of the power supply, an air-cooling system is needed. This paper presents the design of the air-cooling system for the high voltage power supply. The fluid simulation of SF6 based on Fluent and the optimal design of the air duct's structure and the thermal efficiency have been done. The comparison and analysis of the simulation and the empirical formula result is also carried out. It illustrates the design of the air-cooling system can satisfy the demand of the heat radiation This paper also provides an effective method for the optimal design of the air duct's structure and the maximize efficiency of heat exchange.

MOPWA041

The New SLS Beam Size Monitor, First Results

laser, emittance, polarization, synchrotron

759

Á. Saá Hernández, N. Milas, M. Rohrer, V. Schlott, A. Streun
PSI, Villigen PSI, Switzerland
Å. Andersson, J. Breunlin
MAX-lab, Lund, Sweden

Funding: This research has received funding from the European Commission under the FP7-INFRASTRUCTURES-2010-1/INFRA-2010-2.2.11 project TIARA (CNI-PP). Grant agreement no. 261905.
An extremely small vertical beam size of 3.6 μm, corresponding to a vertical emittance of 0.9 pm, only about five times bigger than the quantum limit, has been achieved at the storage ring of the Swiss Light Source (SLS). The measurement was performed by means of a beam size monitor based on the imaging of the vertically polarized synchrotron radiation in the visible and UV spectral ranges. However, the resolution limit of the monitor was reached during the last measurement campaign and prevented further emittance minimization. In the context of the work package “SLS Vertical Emittance Tuning” of the TIARA collaboration, a new improved monitor was built. It provides larger magnification, an increase of resolution and enables two complementary methods of measurement: imaging and interferometry. In this paper we present the design, installation, commissioning, performance studies and first results obtained with the new monitor.

MOPWA051

ZEMAX Simulations for an Optical System for a Diffraction Radiation Monitor at CesrTA

target, simulation, electron, damping

789

T. Aumeyr, V. Karataev
JAI, Egham, Surrey, United Kingdom
M.G. Billing
CLASSE, Ithaca, New York, USA
L.M. Bobb, B. Bolzon, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland

Diffraction Radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The target atoms are polarized by the electric field of the charged particle, which then oscillate thus emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to various electron beam parameters. Since the energy loss due to DR is so small that the electron beam parameters are unchanged, DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in the UV and X-ray spectral-range must be studied. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. This paper reports on simulations carried out with ZEMAX, studying the optical system used to image the emitted radiation.

MOPWA056

Spectra of Coherent Smith-Purcell Radiation Observed from Short Electron Bunches: Numerical and Experimental Studies

electron, diagnostics, simulation, target

801

F. Bakkali Taheri, G. Doucas, I.V. Konoplev, A. Reichold
JAI, Oxford, United Kingdom
H.L. Andrews
LANL, Los Alamos, New Mexico, USA
R. Bartolini
Diamond, Oxfordshire, United Kingdom
V. Bharadwaj, C.I. Clarke
SLAC, Menlo Park, California, USA
N. Delerue
LAL, Orsay, France
N. Fuster Martinez
IFIC, Valencia, Spain
J.D.A. Smith
TXUK, Warrington, United Kingdom
P. Stoltz
Tech-X, Boulder, Colorado, USA

Funding: This work performed [in part] under DOE Contract DE-AC02-7600515
There is a significant interest in the development of compact particle accelerators within research areas including X-ray and THz (T-ray) sources of radiation, particle physics and medical sciences. To support the progress in these areas, non-invasive, electron beam diagnostics that are capable of measuring a single femtosecond electron bunch are required. At the current stage such beam diagnostics for femtosecond-long electron bunches are still not available. The goal of the work presented is to understand the spectral characteristics of coherent Smith-Purcell radiation to enable its quick and reliable interpretation including the longitudinal profile reconstruction of electron bunches. The research presented comprises results from numerical modelling and experimental studies. Using the numerical data, we discuss the radiated spectra dependence on the electron bunch profile and analyse the results. We also discuss the experimental data and compare it with theoretical predictions.

MOPWA063

Proposed Coherent Diffraction Radiation Measurements of Bunch Length at ASTA

electron, cryomodule, gun, laser

822

A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The feasibility of using the autocorrelation of coherent diffraction radiation (CDR) as a non-intercepting diagnostics technique for bunch length and indirectly rf phase measurements is evaluated and proposed for the Advanced Superconducting Test Accelerator (ASTA) facility under construction at Fermilab. Previous experiments on an rf thermionic cathode gun beam at 50 MeV provide a proof-of-principle reference for the ASTA injector. The ASTA injector is based on an L-band rf photocathode (PC) gun with UV pulse drive laser, two L-band superconducting accelerator structures, a chicane bunch compressor, and an electron spectrometer. The injector energy of 40-50 MeV is expected. The 3-MHz micropulse repetition rate with micropulse charges up to to 3.2 nC and 1-ps bunch lengths should generate sufficient CDR signal for standard pyroelectric detectors to be used. The CDR signals will also be evaluated as a bunch compression signal for beam-based feedback for rf phase. The technique would also be applicable at high energy in straight transport lines after the cryomodules.

MOPWA073

A Turn-by-turn Beam Profile Monitor using Visible Synchrotron Radiation at CESR-TA

electron, synchrotron, synchrotron-radiation, emittance

849

S. Wang, D. L. Rubin, C.R. Strohman
CLASSE, Ithaca, New York, USA
R.F. Campbell, R. Holtzapple
CalPoly, San Luis Obispo, California, USA

Funding: Work supported by the National Science Foundation and Department of Energy under contract numbers PHY-0734867, PHY-1002467, DMR-0936384, and DE-FC02-08ER41538, DE-SC0006505
A fast beam profile monitor using visible synchrotron radiation (SR) has been constructed and installed in Cornell Electron Storage Ring. This monitor utilizes fast readout electronics based on the Hamamatsu H7260K multi-anode photomultiplier, which has a 32-channel linear array with 1mm channel pitch and sub-nanosecond rise time. In a low emittance lattice at 2 GeV, a double-slit interferometer is employed to measure the horizontal beam size. After careful calibration of the interference pattern, the horizontal beam size within a range of 100 to 500 microns can be measured with a precision of ±5 microns. Due to finite array size, the small vertical beam size is measured by imaging the pi-polarized component of the SR. The fast beam profile monitor is capable of measuring bunch-by-bunch turn-by-turn transverse beam sizes, which eliminates beam jitter inherent when imaging the average beam size with a CCD camera. Details of hardware and software controls are also discussed.

MOPWA080

Design of a Fast, XFEL-quality Wire Scanner

photon, electron, vacuum, instrumentation

867

M.A. Harrison, R.B. Agustsson, P.S. Chang, T.J. Hodgetts, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, USA

RadiaBeam Technologies, in collaboration with the Pohang Accelerator Laboratory, has designed and built a fast wire scanner for transverse beam size measurements in the XFEL Injector Test Facility. The wire scanner utilizes three 25-micron diameter tungsten wires mounted vertically, horizontally, and diagonally on a single alumina card to measure the transverse beam size down to 10 microns with sub-micron accuracy of a 139-MeV electron beam. A double-ended design using dual bellows for actuation is used to reduce the vibrations of the wire holder during motion and negate the effects of air pressure on positioning. The servomotor-driven system is capable of performing full horizontal, vertical, and 45-degree scans in under a minute. Algorithms are presented for removing the broadening effect of the wires' thickness from the scanning data to measure beams that are as small or smaller than the wires. Furthermore, we present formulas for determining the beam's transverse spatial sizes (horizontal and vertical spot size and correlation) from the scan data.

MOPWO003

Multibunch Tracking Code Development to Account for Passive Landau Cavities

cavity, electron, damping, impedance

885

M. Klein, R. Nagaoka
SOLEIL, Gif-sur-Yvette, France

The MAX IV 3 GeV storage ring will achieve an ultra-low horizontal emittance of 0.24 nm rad by using a multibend achromat lattice. Passive harmonic cavities are introduced to relax the Touschek-lifetime and intrabeam scattering issues as well as fight collective beam instabilities via Landau damping. Since instabilities occur during injection, when the passive harmonic cavity potential is also time varying, it became important to simulate this transient process. The most promising approach was considered to be multibunch tracking which also allows for an arbitrary filling pattern. Since every bunch is represented by numerous macroparticles, internal motions as well as microstructures in the charge distribution can be followed.

MOPWO029

Remote Estimate of Collimator Jaw Damages with Sound Measurements during Beam Impacts

proton, simulation, background, extraction

951

D. Deboy, O. Aberle, R.W. Aßmann, F. Carra, M. Cauchi, J. Lendaro, A. Masi, S. Redaelli
CERN, Geneva, Switzerland

Irregular hits of high-intensity LHC beams on collimators can lead to severe damage of the collimator jaws. The identification of damaged collimator jaws by observation of beam measurements is challenging: online loss measurements at the moment of the impacts can be tricky and degradation of the overall performance from single collimator damage can be difficult to measure. Visual inspections are excluded because collimator jaws are enclosed in vacuum tanks without windows. However, the sound generated during the beam impact can be used to give an estimate of the damage level. In 2012, high-intensity beam comparable to a full nominal LHC bunch at 7 TeV was shot on a tertiary type LHC collimator at the HiRadMat test facility at CERN. The paper presents results from sound recordings of this experiment.

MOPWO037

SixTrack Simulation of Off-momentum Cleaning in LHC

simulation, synchrotron, betatron, synchrotron-radiation

972

E. Quaranta, R. Bruce, S. Redaelli
CERN, Geneva, Switzerland

In the LHC, high-amplitude particles are cleaned by either betatron collimators or momentum collimators. Previously, betatron losses have been considered more important, but measurements during the first years of operation show high losses also in the off-momentum cleaning insertion. This causes a significant radiation dose to warm magnets downstream of the collimators. Our work in this paper aims at simulating with SixTrack the off-momentum particles, driven into the momentum collimators by radiation damping outside the RF system acceptance. The results are an important ingredient in assessing the effectiveness of new passive absorbers to protect the warm magnets.

MOPWO051

Estimate of Warm Magnets Lifetime in the Betatron and Momentum Cleaning Insertions of the LHC

luminosity, betatron, insertion, collimation

1011

B. Salvachua, R. Bruce, M. Brugger, F. Cerutti, S. Redaelli
CERN, Geneva, Switzerland

The CERN LHC collimation system is designed to perform momentum and betatron cleaning in different insertions, respectively IR3 and IR7. The insertions are not perfectly decoupled because the dispersion in IR7 is not null and the beta function in IR3 is not zero. The detailed sharing of losses between the two insertions depends on the relative collimator settings as observed by the change between 2011 and 2012 LHC operation. In this report, using the beam loss measurements at the primary collimators of IR3 and IR7, the total BLM losses in the two insertions are calculated and compared to each other. These studies are also used to quantify the total dose to warm magnets in those IRs with the aim to understand better their lifetime and the implications of the radiation to electronics. This will be of particular importance in view of LHC operating at nominal performance after several years of operation.

MOPWO063

LHeC IR Optics Design Integrated into the HL-LHC Lattice

optics, quadrupole, proton, dipole

1034

M. Korostelev, D. Newton, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O.S. Brüning, R. Tomás
CERN, Geneva, Switzerland
E. Cruz Alaniz, D. Newton, A. Wolski
The University of Liverpool, Liverpool, United Kingdom

The two main drivers for the CDR LHeC IR design were chromaticy and synchrotron radiation. Recently it has been proposed that the LHeC IR proton optics could be integrated into the ATS scheme, which benefits from higher arc beta functions for the correction of chromaticity. In this scenario the distance between the IP and the protron triplet can be increased allowing for a reduction of the IR dipole field and the synchrotron radiation. First feasibility considerations and more in depth studies of the synchrotron radiation effects are presented in this paper.

TUXB201

Short-pulse Operation of Storage Ring Light Sources

storage-ring, electron, photon, optics

1129

A.-S. Müller
KIT, Karlsruhe, Germany

Short-pulse operation of synchrotron light source storage rings can be useful for both the production of IR and THz-band radiation and high repetition rate pump-probe science in the X-ray regime. Different approaches to short-pulse generation include low-alpha optics configurations, two-frequency RF potential manipulation, laser-induced femtoslicing, longitudinal crab-cavity deflection and pseudo-bunch operation with a fast kicker to isolate a single bunch. This talk should review each of these techniques and discuss implications for machine operation in terms of pulse length, beam intensity, beam stability, pulse repetition rate, output radiation beam quality and potential applications.

Slides TUXB201 [12.058 MB]

TUPEA001

Generation of Anomalous Intensive Transition Radiation for FEL

electron, dipole, lattice, polarization

1161

K.B. Oganesyan, A.S. Gevorkyan, E.M. Sarkisyan
ANSL, Yerevan, Armenia
Y. Rostovtsev
University of North Texas, Denton, Texas, USA

The 3D spin-glass system in the external standing electromagnetic field is considered. It is shown on an example of amorphous quartz, under the influence of a standing microwave field, at its certain parameters, superlattice is created in the medium where difference in values of dielectric constants of neighboring layers can be up to third order. Note that this superlattice exists during the nanosecond however it is sufficient for using it as a radiator for generation of transition radiation by relativistic electrons.

TUPEA005

Effects of Quantum Diffusion on Electron Trajectories and Spontaneous Synchrotron Radiation Emission

electron, photon, undulator, synchrotron

1170

I.V. Agapov, G. Geloni
XFEL. EU, Hamburg, Germany
O.V. Chubar
BNL, Upton, Long Island, New York, USA

For various cases, e.g. in the long undulator sections of the European XFEL, quantum diffusion and energy loss have a noticable effect on the electron trajectory, which in turn affects the properties of the emitted radiation. We discuss approaches to modelling the electron dynamics taking this into account and the effect it has on spontaneous radiation emission.

TUPEA006

Towards Realistic Modelling of the FEL Radiation for the European XFEL

simulation, FEL, controls, undulator

1173

I.V. Agapov, G. Geloni
XFEL. EU, Hamburg, Germany

For the operation phase of the European XFEL the possibility to characterize the FEL radiation taking realistic machine model into account is important. To achieve this, a software framework is being developed. It allows for interoperability of various simulation codes by means of a common graphical user interfaces, common input and output files, and common programming model for scripting; it includes the possibility of modeling beam jitters and machine imperfections to set errorbars on the simulation results, and has a connection to the control system for data acquisition. We report on the progress in the developing of this framework and give examples of FEL property calculations performed with it.

TUPEA007

Spontaneous Radiation Calculations for the European XFEL

undulator, electron, emittance, FEL

1176

I.V. Agapov, G. Geloni
XFEL. EU, Hamburg, Germany
O.V. Chubar
BNL, Upton, Long Island, New York, USA
M. Scheer, M. Titze
HZB, Berlin, Germany
N.V. Smolyakov, S.I. Tomin
NRC, Moscow, Russia

Calculating spontaneous radiation emission from long undulators such as those present in the European XFEL, being background to FEL radiation, is still important for several diagnostics and science cases. For realistic setups, and including effects of electron beam focusing, emittance and energy spread in the electron beam, these calculations should be performed numerically. We present these calculations for several electron beam and undulator parameters performed by various codes. Sensitivity of different spontaneous radiation characteristics, in various collection schemes, to the electron beam and undulator magnetic field parameters is studied

TUPEA030

High Brightness and Fully Coherent X-ray Pulses from XFELO Seeded High-gain FEL Schemes

FEL, electron, cavity, undulator

1214

H.X. Deng, C. Feng
SINAP, Shanghai, People's Republic of China

The successful operation of the hard x-ray self-seeding experiment at the LCLS opens the era of fully coherent hard x-ray free electron lasers (FELs). However, the shot-to-shot radiation fluctuation is still a serious issue. In this paper, high-gain, single-pass x-ray FEL schemes seeded by the narrow bandwidth radiation signal from an x-ray FEL oscillator were proposed and investigated, which are expected to generate high brightness, fully coherent and stable x-ray pulse. A simple model has been developed to figure out the temporal and the spectral structures of the output pulses in x-ray FEL oscillator. And options using two synchronized accelerators and using one accelerator were considered, respectively.

TUPEA033

Proposals for Chirped Pulse Amplification in HGHG and CHG at SDUV-FEL

FEL, laser, electron, undulator

1217

C. Feng, L. Shen, D. Wang, D. Xiang, M. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

In this paper, a proposal to generate intense ultra-short free-electron laser (FEL) pulses at Shanghai deep ultraviolet FEL (SDUV-FEL) by combining the chirped pulse amplification (CPA) technique with the high-gain harmonic generation (HGHG) technique is presented. In this proposal, a frequency chirped seed pulse obtained by stretching an ultra-short laser pulse is first used to create frequency-chirped bunching at the laser harmonics in an electron beam; then the frequency chirped harmonic radiation is amplified by an energy chirped electron beam; finally the output radiation pulse which inherits the properties of the seed pulse is compressed to provide an ultra-intense ultra-short radiation pulse. The feasibility and performance of this CPA-HGHG scheme are studied with start-to-end simulations using the parameters of the SDUV-FEL.

TUPEA049

Wakefields of Ultrarelativistic Bunches in Cold Magnetized Plasma

wakefield, plasma, electron, acceleration

1241

S.N. Galyamin, A.V. Tyukhtin
Saint-Petersburg State University, Russia

Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We deal with electromagnetic field of various bunches moving in a cold magnetized plasma along the external magnetic field. The main attention is paid to the case of ultrarelativistic motion. First, for the case of point charge, we obtain the approximate formulas which are valid in the far-field zone and in the vicinity of the charge trajectory. These expressions predict the beating behavior of the far field and the harmonic behavior of the near field. Moreover, the magnitude of the longitudinal components of both electric and magnetic field as well as the transversal electric field possess singularity on the charge trajectory. Second, using formulas for the point charge field as Green function, we develop an effective algorithm for calculation of the bunch wakefield. Plots of wakefields produced by typical bunches are given. Prospects of using the bunch field properties for further development of the plasma wakefield acceleration technique are discussed.

TUPEA061

High-Brightness SASE Studies for the CLARA FEL

undulator, FEL, electron, simulation

1274

R.N.C. Santer, N. Thompson
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The Compact Linear Accelerator for Research and Applications (CLARA) is a proposed 250 MeV FEL test facility to be constructed at STFC Daresbury Laboratory in the UK [1]. This paper presents study of a scheme for the temporal and spectral stabilisation of the SASE output. A feasibility study for the operation of the FEL in a novel High-Brightness SASE mode is presented. Electron beam delays are introduced between undulator sections to disrupt the localised collective FEL process, increase the radiation coherence length and reduce the rms bandwidth. This may extend the range of electron bunch lengths appropriate for the generation of temporally coherent single spike SASE FEL pulses.

TUPEA074

Protection of VUV FEL Mirrors using Soft Orbit Bump at Duke FEL/HIGS facility

FEL, wiggler, electron, dipole

1301

S.F. Mikhailov, H. Hao, J.Y. Li, V. Popov, P.W. Wallace, Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA

Funding: This work is supported in part by the US DoE grant # DE-FG02-97ER41033
The Duke FEL and High Intensity Gamma-ray Source (HIGS) facility is operated with an electron beam from 0.24 to 1.2 GeV and a photon beam from 190 to 1060 nm. Presently, the energy range of the gamma-beam is from 1 MeV to about 100 MeV, with the maximum total gamma-flux of more then 10¹⁰ gammas per second around 10 MeV. Production of high intensity, high energy gamma-beams of 60 to 100 MeV, using UV-VUV mirrors of 240 to 190 nm, requires high energy, high current electron beams of 0.9 to 1.05 GeV. Synchrotron radiation damage to the FEL mirrors becomes crucial for VUV FEL operation at or below 190 nm. The edge radiation (ER) from the End-of-Arc (EOA) bending magnet, instead of the radiation of FEL wigglers, is the dominant cause of a rapid degradation of the downstream FEL mirror. In this work, we describe a further development of the “soft” orbit bump concept to significantly reduce the radiation exposure to the mirror from the EOA dipole magnet. The bump uses designated "soft" orbit correctors with magnetic field limited to produce a radiation with a critical wavelength close or below the FEL wavelength.

TUPFI005

Synchrotron-Radiation Photon Distribution for Highest Energy Circular Colliders

photon, scattering, vacuum, electron

1340

G.H.I. Maury Cuna
CINVESTAV, Mérida, Mexico
G. Dugan, D. Sagan
CLASSE, Ithaca, New York, USA
F. Zimmermann
CERN, Geneva, Switzerland

Funding: Acknowledgements to CINVESTAV, CERN and EPLANET project.
At high energies, beam-induced synchrotron radiation is an important source of heating, beam-related vacuum pressure increase, and primary photoelectrons, which can give rise to an electron cloud. The photon distribution along the beam pipe wall is a key input to codes such as ECLOUD and PyECLOUD, which model the electron cloud build-up. For future high-energy colliders, like TLEP or SHE-LHC, photon stops and antechambers are considered in order to facilitate cooling and vacuum pressure control. We use the Synrad3D code developed at Cornell to simulate the photon distribution for the LHC.

TUPFI013

LHC Long Shutdown: A Parenthesis for a Challenge

cryogenics, controls, vacuum, superconducting-magnet

1355

K. Foraz, M. Arnaud, M.B.M. Barberan Marin, C. Bedel, M. Bernardini, J. Coupard, J. Etheridge, H. Gaillard, S. Grillot, E. Paulat, A.-L. Perrot
CERN, Geneva, Switzerland

After three fruitful years of operation, the LHC will enter a long shutdown. Major works will be implemented to allow running safely at 7TeV/beam. The LHC superconducting circuits will be consolidated; mitigation measures will be carried out to reduce the single event effects occurrence in the frame of the Radiation To Electronics mitigation project (R2E); all the equipment will be fully maintained. In parallel, numerous consolidation and upgrade activities will be performed all around the 27km ring. The schedule has been optimized in order to reduce the length of the shutdown (LS1) to 22 months (including hardware commissioning). The organization of the works is therefore essential to ensure a safe and reliable plan. This paper introduces the various activities to be performed and presents the schedule and the preparation process, including the operational safety aspects.

TUPFI021

FLUKA Energy Deposition Studies for the HL-LHC

luminosity, quadrupole, shielding, optics

1379

L.S. Esposito, F. Cerutti, E. Todesco
CERN, Geneva, Switzerland

The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹*. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches.
O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.

TUPFI042

Beam Parameters and Luminosity Time Evolution for an 80-km VHE-LHC

emittance, luminosity, damping, collider

1442

C.O. Domínguez, F. Zimmermann
CERN, Geneva, Switzerland

The Very High Energy LHC (VHE-LHC) is a recently proposed proton-proton collider in a new 80-km tunnel. With a dipole field of 15-20 T it would provide a collision energy of 76-100 TeV c.m. We discuss the VHE-LHC beam parameters and compute the time evolution of luminosity, beam current, emittances, bunch length, and beam-beam tune shift during a physics store. The results for VHE-LHC are compared with those for HE-LHC, a 33-TeV (20-T field) collider located in the existing LHC tunnel.

TUPFI062

Operational Results of the LHC Luminosity Monitors until LS1

luminosity, proton, monitoring, simulation

1490

A. Ratti, S.C. Hedges, J. Jones, H.S. Matis, M. Placidi, W.C. Turner, V.K. Vytla
LBNL, Berkeley, California, USA
E. Bravin, F. Roncarolo
CERN, Geneva, Switzerland
R. Miyamoto
ESS, Lund, Sweden

Funding: Work funded by the US Department of Energy through the US- LARP program.
The monitors for the high luminosity regions in the LHC have been operating since 2009 to optimize the LHC's luminosity. The devices are gas ionization chambers inside the neutral particle absorber 140 m from the interaction point and monitor showers produced by high energy neutral particles from the collisions. They have the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. The devices have operated on a broad range of luminosity, from the initial 10²⁸ until the levels well beyond 10³³ reached in 2012. We present operational results of the device during proton and lead ion operations until LS1, which include runs at 40 MHz bunch rate and with p-Pb collisions.

TUPME011

Simulated Beam-beam Limit for Circular Higgs Factories

luminosity, synchrotron, simulation, beam-beam-effects

1586

K. Ohmi
KEK, Ibaraki, Japan
F. Zimmermann
CERN, Geneva, Switzerland

We report simulation studies of the beam-beam limit for two proposed circular e⁺e⁻ Higgs factories with circumference of 27 and 80 km, respectively, called LEP3 and TLEP. In particular we investigate the dependence of the steady-state luminosity and transverse beam sizes on the synchrotron tune (or momentum compaction factor) and on the betatron tunes, as well as the consequences of the strong radiation damping and the implications of the large hourglass effect.

TUPME013

Coherent Thomson Scattering using Beam Echo

laser, electron, scattering, undulator

1592

K. Ohmi, S. Kamada
KEK, Ibaraki, Japan
H. Fares
Kanazawa University, Kanazawa, Japan

Longitudinal phase space of the beam is modulated by laser interacting in undulators. The beam can have higher frequency component using the beam echo than than the laser as dicussed by G. Stupakov et al. The modulated beam has a potential to emit coherent radiation with the wave length. We evaluate coherent short wave length (~nm) and/or short pulse (attosec) light source using the beam echo in a low energy accelerator ~100MeV.

TUPME027

Advanced Studies on New Generation of Electron-positron Accelerators and Colliders for Fundamental and Applied Researches

laser, electron, FEL, gun

1631

A. Dudarev, N. Balalykin, U.A. Budagov, V. Kobets, M.V. Lyablin, B.M. Sabirov, G. Shirkov, E. Syresin, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia

JINR actively leads the R&D works in particle accelerator physics and engineering, construction of the free electron laser with the aim to prepare proposals for the project of JINR participation in international collaboration on construction of the future Linear Collider (CLIC/ILC). JINR scientists and engineers study in free electron laser physics, development and construction of systems applied for formation and diagnostics of ultra short dense bunches in the linear electron accelerators. JINR physicists also take part in several fields of activity in ILC: works on photo injector prototype, participation in design and construction of cryomodules, laser metrology, and possible ILC location near Dubna.

TUPME029

VEPP-4: Application Beyond the High Energy Physics

electron, positron, collider, target

1637

O.I. Meshkov
BINP SB RAS, Novosibirsk, Russia

The current status of VEPP-4M electron-positron collider has been described. During fall of 2011 the accelerator was shut down for planned reconstruction of KEDR detector. The next long run of the collider will be dedicated to the experiments at high energy physics within area of 2-5 GeV. Nevertheless, the set of experiments at booster VEPP-3 were continued. VEPP-3 was operated as an SR source, the experiment with internal target was performed and electron/positron scattering at proton was studied. The short runs of VEPP-4M were used as for commissioning of the new “warm” 3T wiggler as for experiments with an extracted electron beam dedicated for testing of different high energy physics detectors. The experiment of comparing of anomalous magnetic moment of electron and positron is con-tinued at VEPP-4M. The system of RF beam shifting is installed at a straight section of the accelerator. It is applied for elimination of parasitic interaction points of electron and positron beams. The first experiments with this system are described. KEDR detector reconstruction should be finished at autumn of 2013. The future experiments with KEDR detector are discussed.

TUPWA024

The Beam Gass Coulomb Scattering in Electron Storage Ring

scattering, simulation, electron, synchrotron

1778

X.L. Yu, Z. Bai, W.W. Gao, W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Among the various factors which determine the beam life time of the HLSII electron storage ring, the beam loss due to the scattering on residual gas is simulated using MC method. The paper will give the process of elastic and inelastic scattering, and the probability of each scattering is calculated, then using MC sampling to decide which particles will participate in the collision. Tracking the beam with scattering of beam-gas included, the spatial distribution of beam will be obtained. Finally we will give the influence analysis of beam-gas scattering.

TUPWA057

Effects of Transient CSR Wakefields on Microbunching in a Bunch Compressor

wakefield, impedance, lattice, FEL

1832

C.E. Mitchell, J. Qiang
LBNL, Berkeley, California, USA

Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The standard analytical model of CSR-induced microbunching in a bunch compressor chicane makes use of a steady-state 1-D model of the longitudinal CSR interaction. This model is numerically generalized to include the effects of transient CSR wakefields due to bend entry and exit, as well as CSR that is generated in upstream bends and propagates across one or more lattice elements before interacting with the beam. The resulting linear integral equation for CSR-induced microbunching is solved numerically for the second bunch compressor of a proposed Next Generation Light Source.

TUPWA069

Longitudinal Phase Space Dynamics with Novel Diagnostic Techniques at FACET

linac, wakefield, klystron, damping

1865

S.J. Gessner, E. Adli, F.-J. Decker, M.J. Hogan, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
A. Scheinker
LANL, Los Alamos, New Mexico, USA

Funding: Work supported [optional: in part] by the U.S. Department of Energy under contract number DE-AC02-76SF00515.
FACET produces high energy density electron beams for Plasma Wakefield Acceleration (PWFA) experiments. The high energy density beams are created by chirping the electron beam with accelerating sections and compressing the beam in magnetic chicanes. Precise control of the longitudinal beam profile is needed for the drive-witness bunch PWFA experiments currently underway at FACET. We discuss the simulations, controls, and diagnostics used to achieve FACET's unique longitudinal phase space.

TUPWO003

CLIC 3 TeV Beam Size Optimization with Radiation Effects

quadrupole, lattice, dipole, photon

1877

O.R. Blanco, P. Bambade
LAL, Orsay, France
R. Tomás
CERN, Geneva, Switzerland

Horizontal beamsize contribution due to radiation on bending magnets is calculated using theoretical results and recent improvements in mapclass (Mapclass2). In order to verify the code and validity of its approximations, a simple lattice with no geometrical nor chromatic aberrations, one dipole and a final drift has been used to compare Mapclass2 calculations and Placet tracking results. CLIC 3TeV lattice is optimized including the radiation effects. Current results show that correction of chromatic aberrations impose constraints in radiation improvement.

TUPWO013

Non-linear Beam Transport Optics for a Laser Wakefield Accelerator

undulator, focusing, electron, optics

1907

C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner
KIT, Karlsruhe, Germany
O. Jäckel, M. Kaluza, M. Reuter
HIJ, Jena, Germany
M. Kaluza, M. Nicolai, T. Rinck, A. Sävert
IOQ, Jena, Germany
M. Scheer
HZB, Berlin, Germany

Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2
The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented.

TUPWO061

Design of a Soft Orbit Bump for FEL Mirror Protection at Duke FEL/HIGS Facility

FEL, electron, synchrotron, synchrotron-radiation

2006

H. Hao, J.Y. Li, S.F. Mikhailov, Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA

Funding: This work is supported in part by the US DOE grant no. DE-FG02-97ER41033.
In an oscillator Free-Electron Laser (FEL) with a high energy electron beam, it is critical to minimize harmful high-energy radiation on the downstream FEL mirror in order to increase its lifetime. At the High Intensity Gamma-ray Source (HIGS) facility at Duke University, effort has been devoted to developing a variety of techniques to reduce the amount of radiation on the FEL mirror. One of the most effective methods was the use of a set of adjustable in-vacuum apertures to block harmonic radiation from FEL wigglers. In recent studies, it was determined that the edge radiation from the end-of-the-arc bending magnet is the main source of UV/VUV and x-ray radiation which causes mirror damage. To mitigate this effect, a soft orbit bump is designed to change the displacement and angle of the electron beam around the end-of-the-arc area. This soft orbit bump is developed using the multi-objective optimization technique. Calculation shows the soft orbit bump can significantly reduce the flux of high energy photons on the FEL mirror. Study is also performed to determine the impact of this orbit bump on the injection, beam lifetime, and the FEL and gamma-ray operation at HIGS facility.

WEZB102

Overview of Seeding Methods for FELs

FEL, electron, undulator, laser

2063

S. Reiche
PSI, Villigen PSI, Switzerland

In recent years enormous progress has been achieved in the theoretical understanding and experimental demonstration of FEL seeding. The state of the art for FEL seeding should be reviewed and compared to HHG, HGHG, EEHG techniques. The potential of various seeding methods and their promise to produce radiation pulses that approach the transform limit in a range of experimental configurations at different user facilities should be explored.

Slides WEZB102 [4.238 MB]

WEODB101

X-ray Spectra and Peak Power Control with iSASE

FEL, undulator, electron, laser

2068

J. Wu, F.-J. Decker, Y. Feng, J. Krzywinski, H. Loos, A.A. Lutman, A. Marinelli, H.-D. Nuhn, C. Pellegrini, D.F. Ratner, D.H. Zhang, D. Zhu
SLAC, Menlo Park, California, USA

Funding: Work is supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515.
We report the first measurement of spectral line-width reduction in a self-amplified spontaneous emission (SASE) X-ray free-electron laser (FEL) obtained by introducing repeated delays of the electron bunch with respect to the radiation field pulse. The improved longitudinal coherence obtained by this method reduces the intensity spiking effect characteristic of a SASE FEL. The electron-photon delays introduced along the FEL undulator mix the spikes phase and amplitude, increasing the cooperation length and generating a smaller bandwidth than in the conventional SASE mode of operation of an FEL. We call this mode of operation, based on repeated electron-photon delays, ‘‘improved SASE'' (iSASE). We also show with theoretical and simulation analysis that in the iSASE mode it is possible to choose the separation and magnitude of the delays to obtain a nearly transform limited X-ray pulse. This analysis is carried out using a time dependent, one-dimensional model and with GENESIS numerical simulation, including three-dimensional effects.

Slides WEODB101 [7.647 MB]

WEOBB202

Ultra-fast Data Acquisition System for Coherent Synchrotron Radiation Based on Superconducting Terahertz Detectors

synchrotron, electron, controls, storage-ring

2094

C.M. Caselle, M. Hofherr, K.S. Ilin, V. Judin, A. Kopmann, A. Menshikov, A.-S. Müller, M. Siegel, N.J. Smale, P. Thoma, M. Weber, S. Wuensch
KIT, Eggenstein-Leopoldshafen, Germany
B.M. Balzer, S. Cilingaryan
Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany

The ANKA synchrotron radiation source located at the Karlsruhe Institute of Technology in Germany operates in the energy range between 0.5-2.5GeV and provides coherent synchrotron radiation. To resolve the ultra-short terahertz pulses emitted by a single bunch, thin YBCO superconducting film detectors have been developed. A response time of 45ps was determined as the FWHM at the output of the analog amplifier. A novel and high accuracy data acquisition architecture for sampling of the individual ultra-short terahertz pulses combined with real-time data processing based on GPUs for coherent synchrotron radiation is presented. The digitizer board is a made-in-house board designed for sampling of the fast pulse signals with pulse width between few tens of picosecond until 100ps. For each terahertz pulse five samples are acquired with a minimum sampling time of 3ps. A prototype setup with terahertz YBCO detectors, digitizer boards and the high-throughput FPGA framework has been successfully developed and tested at ANKA. The overview of the experimental setup including the YBCO detector technology and the preliminary results with single and multi-bunch filling pattern will be discussed.

Slides WEOBB202 [2.416 MB]

WEIB201

Industrial Accelerators

electron, ion, neutron, linac

2100

R.W. Hamm, M.E. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

Particle accelerators, originally developed for basic science research, are increasingly being employed for industrial applications, with the production of these systems itself a worldwide business conducted by more than 70 companies and institutes. Collectively these entities ship more than 1000 systems per year. The industrial applications of these accelerators cover a broad range of business segments from low energy electron beam systems for welding, machining, and product irradiation to high energy cyclotrons and synchrotrons for radioisotope production and synchrotron radiation production. This talk is a review of these business segments and their impact on our lives and the economy. It will also cover new accelerator technology under development that will be used by industry in the future and the predicted growth in the various business segments.

Slides WEIB201 [3.937 MB]

WEIB205

Promoting Local Economic Development by an Integration of Industry, Teaching and Research of Compact Low Energy Accelerators

electron, permanent-magnet, high-voltage, HOM

2119

M. Fan, D.Z. Chen, J. Huang, D. Li, K.F. Liu, B. Qin, Y.Q. Xiong, J. Yang, T. Yu
HUST, Wuhan, People's Republic of China
H.Q. Gao
Hubei University of Science and Technology, Hubei, People's Republic of China

Huazhong University of Science and Technology has been carrying out R&D of compact low energy accelerators by integrating industry, teaching and research to promote local economic development supported by both national and provincial government and local enterprises. Currently, the projects include: compact medical cyclotron, electron irradiation accelerators, etc. The industry of non-power nuclear energy based on low energy particle accelerator has also drawn attention from the provincial government of Hubei and municipal government of Xianning. Meanwhile, a series of lectures about nuclear science and nuclear safety were hosted to help the public better understand nuclear technology and to wipe out fears of nuclear energy. At the moment, the application of non-power nuclear energy with based on compact low energy accelerator is developing into an industry chain in the area of central China.

Slides WEIB205 [2.311 MB]

WEPWA001

Wigglers at Danfysik

wiggler, electron, damping, emittance

2123

C.W.O. Ostenfeld, M. Pedersen
Danfysik A/S, Taastrup, Denmark

In the past 2 years, a number of insertion devices have been designed, assembled and tested at Danfysik. They are used for a variety of applications at free electron lasers and synchrotron radiation facilities. In this paper, we highlight 3 different wiggler projects: A 2.0 T wiggler for Astrid-II in Århus, Denmark, a fixed-gap electromagnetic wiggler for Helmholtz Center Dresden-Rossendorf, and 6 identical damping wigglers for NSLS-2 at Brookhaven National Laboratory (BNL). For the Astrid-2 facility in Aarhus, Denmark, we have designed and built a 6 period wiggler, with a peak field of 2.0 T. The magnetic design and performance is presented and discussed. As part of the ELBE THz facility, at Helmholtz Center Dresden-Rossendorf, we have designed and built a fixed-gap electromagnetic wiggler, with 300 mm period length, and a peak field of 0.39 T. We present the design and magnetic results. For the NSLS-2 project at BNL, damping wigglers are an integral part of the design, both as a means of reducing the emittance, but also as a source of intense radiation sources for users. We present the mechanical and magnetic design, as well as magnetic results obtained for the wigglers.

WEPWA005

Experimental Characterization of the Coherent Harmonic Generation Source at the DELTA Storage Ring

laser, electron, undulator, synchrotron

2132

M. Huck, H. Huck, M. Höner, S. Khan, R. Molo, A. Schick, P. Ungelenk
DELTA, Dortmund, Germany
S. Cramm, L. Plucinski, C.M. Schneider
Forschungszentrum Jülich, Peter-Gruenberg-Institut-6, Jülich, Germany
S. Döring, L. Plucinski, C.M. Schneider
Universität Duisburg-Essen, Duisburg, Germany

Funding: Work supported by DFG, BMBF, and by the Federal State NRW.
The short-pulse facility at the 1.5-GeV synchrotron light source DELTA, operated by the TU Dortmund University, generates coherent VUV and THz radiation by Coherent Harmonic Generation (CHG). Here, a femtosecond laser pulse interacts with an electron bunch in an undulator causing a periodic energy modulation and subsequent micro-bunching, which gives rise to coherent radiation at harmonics of the seed wavelength. Rather than using Ti:Sapphire laser pulses at 795 nm directly, the second harmonic is employed for seeding since 2012. After significant modifications of the seed laser beamline and the dispersive chicane to improve the microbunching, the last commissioning steps include characterization of the CHG radiation and preparing the experimental setup at an existing VUV beamline for time-resolved photoemission spectroscopy. In this paper, the status of the project and recent experimental results are presented.

WEPWA006

Beam Heat Load Measurements with COLDDIAG at the Diamond Light Source

electron, synchrotron, synchrotron-radiation, impedance

2135

S. Gerstl, S. Casalbuoni, A.W. Grau, T. Holubek, D. Saez de Jauregui, R. Voutta
KIT, Eggenstein-Leopoldshafen, Germany
R. Bartolini, M.P. Cox, E.C. Longhi, G. Rehm, J.C. Schouten, R.P. Walker
Diamond, Oxfordshire, United Kingdom
M. Migliorati, B. Spataro
INFN/LNF, Frascati (Roma), Italy

Understanding the heat load from an electron beam is still an open issue for the cryogenic design of superconducting insertion devices. COLDDIAG, a cold vacuum chamber for diagnostics was designed and built specially for this purpose. With the equipped instrumentation, which covers temperature sensors, pressure gauges, mass spectrometers as well as retarding field analyzers it is possible to measure the beam heat load, total pressure, and gas content as well as the net flux and energy of particles hitting the chamber walls. Following a failure after its first installation in November 2011, COLDDIAG was subsequently reinstalled in the Diamond storage ring in August 2012. We report on the preliminary results that have been obtained since then.

WEPWA007

First Tests with a Local and Integral Magnetic Field Measurement Setup for Conduction Cooled Superconducting Undulator Coils

undulator, synchrotron, vacuum, synchrotron-radiation

2138

A.W. Grau, S. Casalbuoni, S. Gerstl, N. Glamann, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany

The magnetic field quality of insertion devices (IDs) has a significant influence on their performance. Therefore it is essential to characterize their magnetic properties and perform precise field measurements before installation in synchrotron light sources. Particularly for permanent magnet IDs the magnetic field measurement technology made significant progress during the last years and pushed the capabilities of synchrotron light sources. Even though for superconducting IDs the measurement settings are far more challenging similar major developments are required. As a part of our R&D program on superconducting IDs we perform quality assessment of their magnetic field properties. This contribution describes details, challenges and the first tests with the measurement equipment configurations to perform measurements of the integral and local magnetic field distributions of superconducting undulator coils up to 2 m length, in a cold (4.2 K), in-vacuum and cryogen free environment.

WEPWA010

FLUTE: A Versatile Linac-based THz Source Generating Ultra-short Pulses

linac, laser, gun, electron

2147

M.J. Nasse, E. Huttel, S. Marsching, A.-S. Müller, S. Naknaimueang, R. Rossmanith, R. Ruprecht, M. Schreck, M. Schuh, M. Schwarz, P. Wesolowski
KIT, Karlsruhe, Germany
R.W. Aßmann, M. Felber, K. Flöttmann, M. Hoffmann, H. Schlarb
DESY, Hamburg, Germany
H.-H. Braun, R. Ganter, L. Stingelin
PSI, Villigen PSI, Switzerland

FLUTE is a linac-based accelerator test facility and a THz source currently being constructed at KIT with an electron beam energy of ~41 MeV. It is designed to cover a large charge range from a few pC to ~3 nC. FLUTE is optimized to provide ultra-short electron bunches with an RMS length down to a few fs. In this contribution, we focus on the layout of the machine from the RF gun & gun laser over the linac and the compressor to the THz beamline for the generation of coherent synchrotron, transition and edge radiation (CSR, CTR, CER).

Poster WEPWA010 [0.802 MB]

WEPWA022

The Fabrication and Measurement of the New Insertion Devices of Hefei Light Source

undulator, vacuum, insertion, insertion-device

2177

Q.K. Jia
USTC/NSRL, Hefei, Anhui, People's Republic of China

To meet the requirements of users for higher brilliance and good transverse coherence VUV and soft X-ray synchrotron radiation, Hefei Light Source(HLS) will be upgraded. After upgrade HLS will have smaller beam emittance and install more new insertion devices. The new insertion devices include one elliptically polarizing undulator with 10⁴ mm period, one in-vacuum undulator with 40mm period, one wiggler with 152mm period and one quasi-periodic undulator based on a new scheme proposed by us. In this paper the fabrication and the preliminary results of the magnetic field measurements of the new insertion devices are reported.

WEPWA024

Study of an Electron Gun for Terahertz Radiation Source

gun, electron, cathode, focusing

2184

J. Li, C. Li, Y.J. Pei, L. Shang
USTC/NSRL, Hefei, Anhui, People's Republic of China
Q.S. Chen, T. Hu
HUST, Wuhan, People's Republic of China
G. Feng
DESY, Hamburg, Germany

With the aim to obtain short-pulse bunches with high peak current for a terahertz radiation source, an RF gun with independently tunable cells (ITC) was employed. As the electron source of the ITC RF gun, a grid-control DC gun plays a key role, the performance of which determines the beam quality in the injector and transport line. In order to make the beam well compressed in the ITC RF gun, the energy of the electrons acquired from the grid-control DC gun should be 15 KeV at most. A proper structure of the grid-gun is shown to overcome the strong space charge force on the cathode, which is able to generate 1us beam with 4.5A current successfully. Simulations considering the grid net are also introduced.

WEPWA038

Influence of Magnet Errors and Waveguide Permeability on Magnetic Field Performance in Pure Permanent Undulators

undulator, FEL, permanent-magnet, simulation

2214

X. Liu, K.F. Liu, B. Qin, P. Tan, B. Wu, Y.Q. Xiong, J. Yang, L. Yang
HUST, Wuhan, People's Republic of China

Abstract For pure permanent magnet (PM) undulator, unavoidable divergences of remanence field and magnetization vector in PM blocks and installation error will cause magnetic field error at the central line of the undulator. This paper presents the simulation results of the magnetic field in non-ideal undulator containing these errors, with specified tolerances in Normal distribution. As well as the peak field error, increases of the harmonic components and impact on field integrals are calculated. The influence on magnetic field caused by waveguide permeability is also discussed.

WEPWA044

Electron Trajectories in a Three-dimensional Undulator Magnetic Field

undulator, electron, focusing, simulation

2223

N.V. Smolyakov, S.I. Tomin
NRC, Moscow, Russia
G. Geloni
XFEL. EU, Hamburg, Germany

In this contribution we present an analysis of electron trajectories in the three dimensional magnetic field from a planar undulator. The electron trajectory is influenced by the focusing properties of the undulator field. In the European XFEL case, long segmented undulators (21 segments for the SASE3 beamline to 35 for SASE1 and SASE2) are planned to be installed, with quadrupole lenses between different segments. These focusing properties should be taken into account in simulations of spontaneous radiation, which constitutes the background signal of the FEL. The ideal magnetic field of an undulator can be described by a sinusoidal vertical magnetic field on the undulator axis, and by horizontal and longitudinal field components that appear out of axis. Exploiting this description for the ideal case, an experimentally measured magnetic field is accounted for by solving the differential equations of motion. The electrons' trajectories for the experimentally measured magnetic field were also simulated numerically. To that aim, a computer code was written, which relies on the Runge-Kutta algorithm. The analytical and numerical methods show a good agreement.

WEPWA062

Status of the UK Superconducting Planar Undulator Project

undulator, cryogenics, vacuum, wakefield

2259

J.A. Clarke, B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
V. Bayliss, T.W. Bradshaw, S.A. Brown, A.J. Brummitt, G.W. Burton, S.J. Canfer, B. Green, S.R. Watson
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
S.E. Hughes, E.C. Longhi, J.C. Schouten
Diamond, Oxfordshire, United Kingdom

The UK is developing a short period, narrow aperture, planar superconducting undulator that is planned to be installed and tested in the 3 GeV Diamond Light Source in 2014. This paper will describe the main parameters of the undulator and the key design choices that have been made. First measurements will be presented of a 19 period test module and also the commissioning of the 2K cryogenic turret.

WEPWA073

Compton Scattering Gamma-ray Light Source Modeling and Optimization

electron, brightness, laser, photon

2283

F.V. Hartemann, R.A. Marsh, S.S.Q. Wu
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
In Compton scattering light sources, a short (ps to ns) laser pulse and a high brightness relativistic electron beam collide to yield tunable, monochromatic, polarized gamma-ray photons. The properties of the gamma-ray phase space is studied, in relation to the full electron bunch and laser pulse phase spaces, along with collimation, nonlinear effects and other sources of spectral broadening. This process has potential high impact applications in homeland security, nuclear waste assay, medical imaging and stockpile surveillance, among other areas of interest. Detailed theoretical modeling is outlined to aid the design of Compton light sources and provide optimization strategies relevant within the context of nuclear photonics applications.

WEPWA077

Aperture Test for Internal Target Operation in the JLAB High-current ERL

FEL, target, electron, diagnostics

2289

S. Zhang, S.V. Benson, G.H. Biallas, K. Blackburn, J.R. Boyce, D.B. Bullard, J.L. Coleman, J. Delk, D. Douglas, P. Evtushenko, C.W. Gould, J.G. Gubeli, F.E. Hannon, D. Hardy, C. Hernandez-Garcia, K. Jordan, J.M. Klopf, R.A. Legg, M. Marchlik, W. Moore, G. Neil, J. Powers, T. Powers, D.W. Sexton, M.D. Shinn, C. Tennant, R.L. Walker, G.P. Williams, F.G. Wilson
JLAB, Newport News, Virginia, USA
J. Balewski, J. Bernauer, W. Bertozzi, R.F. Cowan, P.F. Fisher, E. Ihloff, A. Kelleher, R. Milner, L. Ou, B.A. Schmookler, c. Tschalär
MIT, Cambridge, Massachusetts, USA
N. Kalantarians
Hampton University, Hampton, Virginia, USA

Funding: Supported by the Commonwealth of Virginia, U.S. DOE Nuclear and High Energy Physics, and by the U.S. DOE Basic Energy Sciences under contract No. DE-AC05-060R23177.
A high current beam transmission test has been successfully completed at the JLAB FEL Facility, culminating in very low-loss transmission of a high current CW beam through a small aperture. The purpose of this test was to determine if an ERL is capable of meeting the stringent requirements imposed by the use of a 10¹⁸/cm³ internal gas target proposed for the DarkLight experiment*. Minimal beamline modifications were made to create a machine configuration that is substantially different from those used in routine UV or IR FEL operation. A sustained (8 hour) high power beam run was performed, with clean transmission through a 2 mm transverse aperture of 127 mm length simulating the target configuration. A beam size of 50 um (rms) was measured near the center of the aperture. Experimental data from a week-long test run consistently exhibited beam loss of only a few ppm on the aperture while running 4.5 mA current at 100 MeV – or nearly 0.5 MW beam power. This surpassed the users’ expectation and demonstrated a unique capability of an ERL for this type of experiments. This report presents a summary of the experiment, a brief overview of our activities, and outlines future plans.
References:
* P. Fisher, et al.,“Jlab PR-11-008: A Proposal for the DarkLight Experiment at the Jefferson Laboratory Free Electron Laser.” http://www.jlab.org/exp_prog/proposals/11prop.html

WEPWA080

Development of a Compact Insertion Device for Coherent Sub-mm Generation

linac, laser, impedance, wakefield

2295

A.V. Smirnov, R.B. Agustsson, S. Boucher, T.J. Grandsaert, J.J. Hartzell, M. Ruelas, S. Storms
RadiaBeam, Santa Monica, USA
A. Andrews, B.L. Berls, C.F. Eckman, K. Folkman, A.W. Hunt, Y. Kim, A.E. Knowles-Swingle, C. O'Neill, M. Smith
IAC, Pocatello, IDAHO, USA
P. Buaphad, Y. Kim
ISU, Pocatello, Idaho, USA

Funding: Department of Energy Contracts DE- SC-FOA-0000760 and DE-FG02-07ER84877
A novel design of resonant Cherenkov wakefield extractor that produced a ~0.9 mm wavelength radiation is presented. The experiment was performed at Idaho Accelerator Center (IAC) using specially upgraded 1.3 GHz 44 MeV linac facility. Specifics of the radiator performance and design are outlined including low-energy beam interaction with non-circular geometry. Some elements of the design may have certain potential for future compact mm-sub-mm-wave sources.

WEPWA081

Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications

undulator, cryogenics, vacuum, simulation

2298

F.H. O'Shea, R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh, K.E. Woods
RadiaBeam, Santa Monica, USA
J. Park, R.L. Stillwell
NHMFL, Tallahassee, Florida, USA
V. Solovyov
BNL, Upton, Long Island, New York, USA

The demand for high-brightness hard x-ray fluxes from next generation light sources has spurred the development of insertion devices with shorter periods and higher fields than is feasible with conventional materials and designs. RadiaBeam Technologies is currently developing a novel high peak field, ultrashort period undulator with praseodymium-iron-boron (PrFeB) permanent magnets and textured dysprosium (Tx Dy) ferromagnetic field concentrators. This device will offer an unparalleled solution for compact x-ray light sources, as well as for demanding applications at conventional synchrotron radiation sources. A 1.4T on-axis field has already been achieved in a 9mm period undulator, demonstrating the feasibility of using Tx Dy poles in a hybrid undulator configuration with PrFeB magnets. Facets of the undulator design, optimization of the Tx Dy production and characterization process, and magnetic measurements of Tx Dy will be presented.

WEPWO013

High Power Tests of Injector Cryomodule for Compact-ERL

cavity, cryomodule, HOM, accelerating-gradient

2340

E. Kako, D.A. Arakawa, K. Hara, T. Honma, H. Katagiri, Y. Kojima, Y. Kondo, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Shishido, T. Takenaka, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan
H. Hara, H. Hitomi, K. Sennyu
MHI, Kobe, Japan

In the cERL injector cryomodule, electron beams of 10 mA are accelerated from the beam energy of 500 keV to 5 MeV. A three 2-cell cavity system was chosen for the cERL injector. Each cavity is driven by two input couplers to reduce a required RF power handling capacity and also to compensate a coupler kick. In the cERL injector cryomodule, critical hardware components are not superconducting cavities but RF input couplers operating in CW mode. Six input couplers for the installation in the cryomodule were fabricated, and three pairs of input couplers were carefully conditioned. Costruction status, cool-down tests and high power RF test results on injector cryomodule for compact-ERL at KEK will be discussed in this paper.

WEPWO016

Construction of Main Linac Cryomodule for Compact ERL Project

HOM, cryomodule, cavity, linac

2349

K. Umemori, K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

Compact ERL (cERL), which is a test facility of ERL, is under construction at KEK, in Japan. At the first stage of cERL project, electron beam will be accelerated by 30 MV at main linac region. We have developed a main linac cryomodule, which contains two L-band 9-cell superconducting cavities. Cavity assembly work was carefully done at a class-10 clean room and HOM absorbers and cold windows of input couplers were successfully mounted on the cavities. Next, the frequency tuners, thermal anchors, magnetic shields and temperature sensors and so on were assembled to the cryomodule. Then, using a clean-booth, warm windows of the input couplers are connected to the cold windows and gate valves were also attached to the both ends of the cryomodule. Finally, the cryomodule was installed into the beamline of cERL and connected to a 2K cryogenic system. Target of alignment precision of the cavities, after cooling down to 2K, are set to be within 1 mm against the beamline. The first cool-down test, followed by low power and high power measurements, is scheduled within the year 2012.

WEPEA011

Bursting Patterns of Coherent Synchrotron Radiation in the ANKA Storage Ring

impedance, simulation, electron, synchrotron

2516

M. Schwarz, V. Judin, A.-S. Müller
KIT, Karlsruhe, Germany
M. Klein
SOLEIL, Gif-sur-Yvette, France

We report measurements of bursting patterns of coherent synchrotron radiation (CSR) for a wide range of single bunch currents at the ANKA storage ring. The radiation was detected with a fast THz detector, a Hot Electron Bolometer, and its signal acquired with both a spectrum analyzer and an external sampling oscilloscope. Both analysis methods consistently show the onset of bursting at a threshold current with the appearance of strong high frequency bands with higher harmonics in the several 10th of kHz range. For currents higher than twice the threshold value an abrupt change in the bursting pattern occurs. These results are compared with different numerical models solving the one-dimensional Vlasov-Fokker-Planck equation.

WEPEA027

Nonlinear Model Calibration in Electron Storage Rings via Frequency Analysis

sextupole, betatron, storage-ring, damping

2558

G. Liu, W. Li, L. Wang, K. Xuan
USTC/NSRL, Hefei, Anhui, People's Republic of China

Frequency analysis of turn-by-turn BPM data is a very useful numerical method for analysing the detrimental effect of the nonlinear resonances in storage rings, and which has been widely used for nonlinear resonances measurement and correction. We applied this method in this paper for calibrating the nonlinear model by numerical fitting of the sextupole components with the effect of radiation damping and decoherence of the betatron oscillation in HLSII storage ring.

WEPEA041

Actions To Mitigate The Radiation Damage to Electronics at the LHC

shielding, hadron, controls, civil-engineering

2591

A.-L. Perrot, M.B.M. Barberan Marin, J.-P. Corso, K. Foraz, M. Lazzaroni, Y. Muttoni
CERN, Geneva, Switzerland

The level of flux of hadrons with energy in the multi MeV range expected from the collisions at the LHC interaction Points 1, 5 and 8 and from the collimation system at Point 7 will induce Single Event Errors (SEEs) in the standard electronics present in many of the control equipment installed in LHC underground. Furthermore, a risk of SEEs induced by thermal neutrons cannot be excluded. Such events would perturb the LHC operation, possibly leading to a stop of the machine. Main mitigation actions will be implemented during the first LHC Long Shutdown of 2013/2014 (LS1) to reduce the SEE occurrence. This paper summarizes the mitigation measures and their associated foreseen improvements in terms of SEEs. It presents the organization process and associated planning highlighting the impacts with the overall LHC LS1 planning and the main concerns during implementation.

WEPFI036

R&D on a Main Accelerating Section of a Compact THz-FEL

electron, laser, FEL, simulation

2780

W. Bai, M. Li, X. Shen, H. Wang, X. Yang
CAEP/IAE, Mianyang, Sichuan, People's Republic of China

In order to develop a tera-hertz(THz) radiation source and to make scientific researches on application of THz technology, a study on tera-hertz source is performed. The radiation source is based on technology of free electron laser(FEL). The energy booster section of the injector uses a 9 Cell standing wave accelerator as the main accelerator for the FEL. The accelerator works at S band.(2856 MHz), excited by a microwave power of about 3.5 MW. At the end of the accelerator, the high quality beam energy is of 6.5MeV ~ 7 MeV, and the current about 300 mA. This paper presents the newly prgress of the , as well as the working condition of the main accelerator.

WEPFI054

Enlargement of Tuning Range in a Ferrite-tuned Cavity through Superposed Orthogonal and Parallel Magnetic Bias

cavity, factory, resonance

2812

C. Vollinger, F. Caspers
CERN, Geneva, Switzerland

Conventional ferrite-tuned cavities operate either with bias fields that are orthogonal or parallel to the magnetic RF-field. For a cavity that tunes rapidly over an overall frequency range around 100-400 MHz with high Q, we use ferrite garnets exposed to an innovative new biasing method consisting of a superposition of perpendicular and parallel magnetic fields. This method leads to a significant enlargement of the high-Q cavity tuning range by defining an operation point close to the magnetic saturation and thus improving ferrite material behaviour. A further advantage of this technique is the fast tuning speed resulting from the fact that tuning is carried out either with pure parallel biasing, or together with a very small change of operating point from perpendicular bias. In this paper, several scaled test models of ferrite-filled resonators are shown; measurements on the set-ups are compared and discussed.

WEPFI072

Analysis of Breakdown Damage in an 805 MHz Pillbox Cavity for Muon Ionization Cooling R&D

cavity, site, cathode, plasma

2857

D.L. Bowring, D. Li
LBNL, Berkeley, California, USA
A. Moretti, Y. Torun
Fermilab, Batavia, USA

When operating in multi-Tesla solenoidal magnetic fields, normal-conducting cavities exhibit RF breakdown at anomalously low gradients. This breakdown behavior may be due to field-emitted electrons, focused by the magnetic field into "beamlets" with relatively large current densities. These beamlets may then cause pulsed heating and cyclic fatigue damage on cavity interior surfaces. If this model is correct, materials with long radiation lengths (relative to copper) may alleviate the problem of RF breakdown in strong magnetic fields. To study this phenomenon, RF breakdown was induced on pairs of "buttons" in an 805 MHz pillbox cavity. The shape of the buttons creates a local enhancement of the surface electric field, such that breakdown occurs preferentially on the button surface. Beryllium and copper buttons were tested in order to evaluate the effect of radiation length on RF breakdown performance. This poster presents an analysis of the damage to these buttons and suggests a path forward for future materials R&D related to breakdown in strong magnetic fields.

WEPME027

Analysis of Tidal Effects on Measurement Accuracy of HLS

alignment, site, synchrotron, synchrotron-radiation

2989

S.F. Xu, X.Y. He, P. Wang, W. Wang, Q.Y. Yao
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Natural Science Foundation of China
HLS* is mainly used in survey and high-accuracy alignment in particle accelerator. Monitoring the earth tides is primarily introduced in this paper. Based on the earth tide theory and the ocean load effects on the planet earth, the tidal effects on a hydrostatic leveling system is analyzed. Finally, the local ground deformation is obtained,and the current research establish a foundation for the further study.
HLS-hydrostatic levelling system

WEPME055

Investigation of Source Point Instabilities in Dipole Magnet Based Beamlines

dipole, synchrotron, feedback, optics

3055

M. Apollonio, R. Bartolini
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

At Diamond the source point in the second dipole of the Double Bend Achromats can vary due the lack of adjacent BPMs constraining angle and position of the electron beam at the dipole. We have implemented a code based on our AT model to predict the effects of a corrector strength change and compared our predictions to data both from a beamline and from our pinhole cameras. We discuss the possibility of interfacing the code to a ray tracing routine in order to infer beam spot changes in the downstream beamline and suggest a procedure to restore the original source point.

THOAB201

Development of the Dielectric Wall Accelerator

proton, dipole, simulation, shielding

3115

A. Zografos, T. Brown, C. Cohen-Jonathan, C. Hettler, F. Huang, V. Joshkin, K. Leung, M. Moyers, Y.K. Parker, D. Pearson, M. Rougieri
CPAC, Livermore, CA, USA
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton beam therapy. The Dielectric Wall Accelerator engineering prototype includes a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked transmission to produce the required voltage. The transmission lines are switched with solid state laser driven optical switches. A computational model has been developed that is in very good agreement with the experimental results. The system is presently achieving accelerating gradients of approximately 15 MeV/m. The computational model has been used to design the next generation system that will achieve 25 MeV/m by early 2013. This paper will discuss the status of the apparatus, the basic elements of the computational model, experimental results and comparison to the model predictions. In addition, the paper will present concepts for proton therapy systems that incorporate the Dielectric Wall Accelerator and fully leverage its features to achieve clinical requirements.

Slides THOAB201 [1.650 MB]

THPPA03

The Development of China’s Accelerators I Have Experienced

proton, synchrotron, luminosity, linac

3144

S.X. Fang
IHEP, Beijing, People's Republic of China

The development of China’s high energy accelerator for half a century falls into two stages, namely the first 20 hovering years (1958-1978) and the later 30 years of rapid development (from 1978 till now). I was lucky enough to have experienced the whole process, witnessed, and to some extent, joined in the decision-making, the projects approval, the designing, the development and construction of China's five large scientific facilities undertaken by the Institute of High Energy Physics in Beijing. A brief review is given of the previous stage of history regarding the consideration of China’s high energy accelerators in the first 20 years. A short presentation is also given of the later 30 years concerning the rapid development of the Beijing Electron-Positron Collider (BEPC and BEPCII), the completed BEPC-based Shanghai Synchrotron Radiation Facility (SSRF), the Chinese Spallation Neutron Source (CSNS) under construction, the high-intensity proton accelerator (ADS) used for nuclear waste transmutation and the proton therapy machine in the R&D stage.

Slides THPPA03 [6.015 MB]

THPEA008

Study on the Energy Response of a Multi-layer Planar High Pressure Ionization Chamber using MCNP Program

photon, simulation, ion, electron

3164

Y.D. Ding, P.F. Wang, Q.B. Wang, Q.J. Zhang
IHEP, Beijing, People's Republic of China

High pressure ionization chamber is widely used to detect various radiation fields due to its good energy response. A new Multi-layer planar high pressure ionization chamber is designed suitable for measuring directional radiation field of high dose rate, because of its high electric field strength. In this paper, MCNP program is used to simulate and calculate the energy response of this ionization chamber to obtain the energy response of high energy photons, which could not be obtained by experimental methods. The results show that this ionization chamber can measure photon radiation energy up to 10MeV.

THPEA015

Induced Radioactivity Research for Scraper

electron, radioactivity, linac, synchrotron

3173

L.J. He, Y.K. Chen, W. Li
USTC/NSRL, Hefei, Anhui, People's Republic of China

The 200MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in China. The electrons are accelerated to 200MeV by five accelerating tubes and collimated by the scraper followed each accelerating tube. The scraper aperture is smaller than the accelerating tube,so some electrons will hit on the structure materials when they pass through them. These lost electrons will cause induced radioactivity due to bremsstrahlung, cascade shower and photo-nuclear reaction. This paper gives the simulation to different energy electrons lost at the corresponding scraper by EGSnrc. The results showed that electrons were lost mainly at the scraper during the accelerating period,and the actual measurement confirmed this. Meanwhile,the induced radionuclide types have been studied. Recently,the linac mentioned above has been retired because of upgrading. The equipments and materials removed are used to study induced radioactivity generated in different materials. The research will provide the theoretical basis for the similar accelerator decommissioning plan,and is also significant for accelerator structure design,material selection and radiation protection programs design.

THPEA026

Radiation Safety Interlock System for DCLS

controls, electron, monitoring, dipole

3198

G. Wang, S. Liu, J.J. Lu, X. Xia, J.Q. Xu, Y. Xu, F. Yang
SINAP, Shanghai, People's Republic of China

Dalian Coherent Light Source (DCLS) is in the design phase currently and will be constructed in Dalian from 2013. It is a seeded HGHG-FEL, mainly consisting of one 300 MeV electron linear accelerator and one undulator. Radiation safety is one of the most important tasks for Dalian FEL. Radiation safety interlock system (RSIS) is designed to prevent personnel exposure to high radiation levels, based on the As Low As Reasonably Achievable (ALARA) principle. RSIS controls access to the radiation protection areas and monitors safety devices. Only if all the radiation safety conditions are satisfied, then the facility will be permitted to operate. Once any condition is broken, RSIS will send a signal to stop the electron beam immediately to guarantee radiation safety. The core component of RSIS utilizes Programmable Logic Controller (PLC), which is a proven and reliable technology in the field of industrial automatic control. All safety-relevant functions of RSIS are implemented with fail-safe components. The hard wiring cable of the peripheral signals for the safety-relevant functions is redundant. The safety interlock signals are sent via a fail-proof protocol and transferred redundantly.

THPEA027

Radiation Calculations for Advanced Proton Therapy Facility

shielding, proton, simulation, target

3201

J.Q. Xu, J.J. Lu, G. Wang, X. Xia
SINAP, Shanghai, People's Republic of China

The shielding calculations for Advanced Proton Therapy Facility (APTRON), which is under design in Shanghai, were carried out. The thickness of radiation shielding walls for the accelerator and treatment rooms of APTRON were determined by Monte Carlo simulation and empirical formula. Beam loss scenarios and workloads of different energy at LINAC, synchrotron, beam transport line and treatment are given for the calculations. The calculations were carried out for the proton energy of 150MeV, 220MeV and 250MeV, and the targets of iron and equivalent tissue material. Source terms and attenuation length were calculated with different angles by the simulation using FLUKA code. Based on the source terms and the attenuation length, the thickness of the bulk walls were determined. Local shielding and maze design were also concerned.

THPEA039

Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN

linac, shielding, neutron, simulation

3225

J. Blaha, J. Vollaire
CERN, Geneva, Switzerland

Linac4, a new 160 MeV H⁻ accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models.

THPEA040

Design of a Magnetic Bump Tail Scraping System for the CERN SPS

injection, beam-losses, extraction, closed-orbit

3228

Ö. Mete, J. Bauche, F. Cerutti, S. Cettour Cave, K. Cornelis, L.N. Drøsdal, F. Galleazzi, B. Goddard, L.K. Jensen, V. Kain, Y. Le Borgne, G. Le Godec, M. Meddahi, E. Veyrunes, H. Vincke, J. Wenninger
CERN, Geneva, Switzerland
A. Mereghetti
UMAN, Manchester, United Kingdom

The LHC injectors are being upgraded to meet the demanding beam specification required for High Luminosity LHC (HL-LHC) operation. In order to reduce the beam losses which can trigger the sensitive LHC beam loss interlocks during the SPS-to-LHC beam injection process, it is important that the beam tails are properly scraped away in the SPS. The current SPS tail cleaning system relies on a moveable scraper blade, with the positioning of the scraper adjusted over time according to the orbit variations of the SPS. A new robust beam tail cleaning system has been designed which will use a fixed scraper block towards which the beam will be moved by a local magnetic orbit bump. The design proposal is presented, together with the related beam dynamics studies and results from machine studies with beam.

THPEA042

TREC: Traceability of Radioactive Equipment at CERN

HOM, controls, monitoring, background

3234

M.P. Kepinski, L. Bruno, Ch. Delamare, S. Mallon Amerigo, P. Martel, S. Petit, T. Schmittler, M.J.S. Tavlet, D. Widegren
CERN, Geneva, Switzerland

Activated accelerator components are frequently removed from service due to changes in design, configuration or maintenance work. Safe and effective management of such components is a necessity. Moreover, local authorities require the tracking of this equipment: any piece of equipment or waste which has been in a potentially radioactive area must be controlled by a radio protection responsible before leaving the accelerator premises. CERN must also be able to prove that the required measurements have been done and are properly stored in a computerized system. TREC is the official system used at CERN to trace potentially radioactive equipment. It replaces paper work by electronic data, manual phone calls by automatic email notifications and helps to enforce CERN safety rules. Some of the major benefits are the reduction of the delays related to equipment movements (from installation to workshops or waste storage areas) as well as increased personal safety. The system is fully integrated with the CMMS* tools used at CERN to ensure the complete equipment lifecycle’s traceability.
*CMMS: Computerized Maintenance Management System

THPEA043

An Equipment Hub for Managing a Small Town and a Complex Machine

controls, coupling, status, collider

3237

P. Martel, A. Alexandre Metola, Ch. Delamare, M.P. Kepinski, S. Mallon Amerigo, L. Pater, S. Petit, D. Widegren
CERN, Geneva, Switzerland

Effective maintenance of the accelerators’ complex is vital for CERN’s mission. While this work is highly dependent on operational planning and constraints, it also needs to be coordinated with the maintenance of the infrastructure where the complex is embedded. The nature and degree of the logistics problems that arise from this interdependence cannot be handled by partial, decoupled solutions from each of the stakeholders. CERN’s Enterprise Asset Management system is the central hub where all relevant data about equipment and its maintenance is kept. It is also where data and documents about the manufacturing, installation, safety inspection, radiation measurements, disposal, etc. of the scientific equipment reside. This hub allows the effective sharing of consistent equipment data, accessed by a large number of people and systems, and supplies a wide range of interfaces – ranging from the user in the field with no access to a desktop computer, to scheduling systems that need to interact with it through Web services; this is achieved by means of a series of systems, tools and mechanisms, all dedicated to different needs but working on the same data and sharing common policies.

THPEA044

Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors

proton, cryogenics, beam-losses, monitoring

3240

C. Kurfuerst, C. Arregui Rementeria, M.R. Bartosik, B. Dehning, T. Eisel, M. Sapinski
CERN, Geneva, Switzerland
V. Eremin, E. Verbitskaya
IOFFE, St. Petersburg, Russia
C. Fabjan
HEPHY, Wien, Austria
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

At the triplet magnets, close to the interaction regions of the LHC, the current Beam Loss Monitoring system is sensitive to the particle showers resulting from the collision of the two beams. For the future, with beams of higher energy and intensity resulting in higher luminosity, distinguishing between these interaction products and possible quench-provoking beam losses from the primary proton beams will be challenging. Investigations are therefore underway to optimise the system by locating the beam loss detectors as close as possible to the superconducting coils of the triplet magnets. This means putting detectors inside the cold mass in superfluid helium at 1.9 K. Previous tests have shown that solid state diamond and silicon detectors as well as liquid helium ionisation chambers are promising candidates. This paper will address the final open question of their radiation resistance for 20 years of nominal LHC operation, by reporting on the results from high irradiation beam tests carried out at CERN in a liquid helium environment.

THPEA047

Diamond Particle Detector Properties during High Fluence Material Damage Tests and their Future Applications for Machine Protection in the LHC

simulation, target, proton, beam-losses

3249

F. Burkart, J. Blanco, J. Borburgh, B. Dehning, M. Di Castro, E. Griesmayer, A. Lechner, J. Lendaro, F. Loprete, R. Losito, S. Montesano, R. Schmidt, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

Experience with LHC machine protection (MP) during the last three years of operation shows that the MP systems sufficiently protect the LHC against damage in case of failures leading to beam losses with a time constant exceeding 1ms. An unexpected fast beam loss mechanism, called UFOs, was observed, which could potentially quench superconducting magnets. For such fast losses, but also for better understanding of slower losses, an improved understanding of the loss distribution within a bunch train is required. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been developed and successfully tested in the LHC and in experiments to quantify the damage limits of LHC components. This paper will focus on experience gained in use of diamond detectors. The properties of these detectors were measured during high-fluence material damage tests in CERN's HiRadMat facility. The results will be discussed and compared to the cross-calibration with FLUKA simulations. Future applications of these detectors in the LHC to understand beam losses and to improve the protection against fast particle losses will be discussed.

THPEA062

Magnetic Field Measurements for the IAC-RadiaBeam THz Project

dipole, quadrupole, electron, FEL

3282

P. Buaphad, Y. Kim, M. Williams
ISU, Pocatello, Idaho, USA
A. Andrews, T. Downer, C.F. Eckman, Y. Kim, M. Smith
IAC, Pocatello, IDAHO, USA

At the Idaho Accelerator Center (IAC) of Idaho State University, recently, a new chicane with four dipoles and quadrupole triplet magnets were installed in a 44 MeV linac to perform the IAC-RadiaBeam Terahertz (THz) project. To generate high power THz radiation, a THz radiator with numerous periodic gratings was also installed downstream of the quadrupole triplet. However, the electron beam shape at the radiator has to be horizontally focused strip-like one due to a tiny radiator gap with a width of 1.2 mm, and electron bunch length should be about a few picosecond (ps) to generate high power THz radiation in the radiator. By using the quadrupole triplet and chicane dipoles, we can control the transverse beam profile and bunch length freely. In this paper, we report the measured field maps of the dipole and quadrupole magnets, their effective lengths, and field strength or gradient as a function of the magnet power supply current.

THPFI011

Thermal Simulations of Charge-exchange Stripper Foils for High-melting-point Materials

stripper, simulation, injection, proton

3312

Y. Takeda
KEK, Ibaraki, Japan
M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Charge-exchange stripper foils can be very quickly broken by high-current beams. Hence, a long-lived foil that can withstand prolonged beam irradiation is eagerly awaited. It is well known that the maximum temperature of the foil plays an important role in the foil lifetime. Therefore, the temperature distribution map and the maximum temperature of the foils were investigated in detail by using simulation software of the finite element method and applications with ANSYS. Moreover, the heating properties of several kinds of high-melting-point materials were researched. According to the results, stripper foils of the same effective thickness showed drastically different maximum temperatures, differing by up to about 200 K. From these results, we show that the emissivity and specific heat of the foil considerably influences its maximum temperature.

THPFI020

Radiation Shielding Design for Medical Cyclotrons

shielding, cyclotron, proton, target

3339

F. Wang, T. Cui, X.L. Jia, Z.G. Li, T.J. Zhang, X.Z. Zhang
CIAE, Beijing, People's Republic of China

With the increasing applications of cyclotrons in health care, a number of cyclotrons ranging from several MeVs to hundreds MeVs have used for radio diagnostic and radiation therapy. A 14 MeV PET cyclotron, CYCIAE-14, has been installed in a shielding building for tests at CIAE that can be used for FDG production and boron neutron capture therapy (BNCT). In the mean time, the development of a 235MeV cyclotron, CYCIAE-235, which can be used for proton therapy, is in progress at the same laboratory. In terms of the cyclotron application in factories and hospitals, an appropriate radiation shielding design is of critical importance. In the case of CYCIAE-14 and CYCIAE-235, the neutron source of different cyclotrons has been estimated to define the thickness of the total shielding, and the concrete is selected as the main shielding material. For CYCIAE-14 specifically, local shielding has been implemented. This paper will give an introduction to the radiation shielding design for CYCIAE-14 and CYCIAE-235 respectively. The typical layout for the application of the two machines is presented in this paper which can be applied in factories and hospitals as well.

THPFI022

The M-C Application in Designing Tailored Cryopump Used in Cyciae-100 Cyclotron

vacuum, cyclotron, beam-losses, ion

3342

S.P. Zhang, Z.G. Li, G.F. Pan, J.S. Xing, F. Yang, T.J. Zhang
CIAE, Beijing, People's Republic of China

A compact high intensity cyclotron CYCIAE-100 was selected as the driver for the Beijing Radioactive Ion Facility (BRIF). A pressure of 5×10-8 mbar is required to achieve acceptable beam losses in the CYCIAE-100 cyclotron. As the existing ports on the cyclotron valley are insufficient to provide enough pumping speed using commercially available pumps, two tailored cryopanels with a pumping speed of 60000 l/s for each are designed. Based on the Monte-Carlo method, a mathematical model of molecular movement and collision between the panels and their shield was developed. The ratio of molecular reflected to the baffle to molecular passing through the baffle is the sticking probability on the panels. When taking the transmission probability of the chevron baffle, capture coefficient of cryopanel can be calculated. It could provide a reference to design the cryopanel shape and its condensation area.

THPFI025

Design and Experimental Results of an Electro-static Pre-chopper for CSNS LEBT

rfq, power-supply, simulation, cavity

3351

H.C. Liu, S. Fu, K.Y. Gong, H.F. Ouyang, J. Peng
IHEP, Beijing, People's Republic of China

The China Spallation Neutron Source (CSNS) front end incorporates a pre-chopper in the Low Energy Beam Transport line (LEBT) that will remove a 530ns section of beam at approximately 1MHz rate, which is the RF frequency of the ring at injection. It’s one of the most critical devices for properly controlling the injecting beam loss. Physical designing of the pre-chopper is carried out, and the RFQ itself was used as the beam dump of the chopper system. In order to examine the reliability of the pre-chopper design, the beam study of a similar chopper system was successfully performed. Results of physical design and experiments will be presented.

THPFI029

The Structure Design and Analysis of Proton Beam Window for CSNS

target, proton, scattering, neutron

3361

H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu
IHEP, Beijing, People's Republic of China

The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). In this paper, a new designed PBW structure called single-double layer structure is discussed. The new structure will be used in CSNS, and it is designed based on the beam characteristic of CSNS, which power is 100 kW. The structure design and thermal-analysis are presented, and the convective coefficient of cooling water is calculated. Besides, the radiation damage is discussed to assure there is no danger of radiation lifetime of PBW.

THPFI032

The Design and Analysis of Proton Beam Window for CSNSIII

scattering, proton, target, neutron

3367

H.J. Wang, L. Kang, R.H. Liu, H. Qu, D.H. Zhu
IHEP, Beijing, People's Republic of China

The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). When the beam power of CSNS upgrades from 100kw to 500kw (CSNSIII), the present single-double layer structure of PBW cannot meet the demands. The PBW will be changed to other structure. This paper discusses sandwiched structure and multiple pipe structure, and the later one is chosen as the PBW of CSNSIII. An appropriate convective coefficient of cooling water is chosen, based on which the detailed thermal-stress analysis is presented. Besides, the lifetime is estimated. All these analyses show the designed PBW can work well in CSNSIII.

THPFI040

DEVELOPMENT OF A TARGET SYSTEM FOR RARE ISOTOPE BEAM PRODUCTION WITH HIGH-POWER HEAVY-ION BEAMS*

target, electron, ion, vacuum

3373

J.-W. Kim, S. Hong, J.H. Kim, M. Kim, J. Song
IBS, Daejeon, Republic of Korea

To produce rare isotope beams, in-flight fragmentation method utilizing a thin target and heavy-ion primary beam can be used. The existing facilities provide the maximum primary beam power of a few kW, while the next generation facility is planned to use hundreds of kW of 238U beam. We are designing a rare-isotope beam facility, which can provide U beam with the maximal power of 400 kW at the energy of 200 MeV/u. The high-power target studied is made of multi-slice rotating graphite to enhance radiation cooling. The total target thickness is roughly 2 mm with more than 10 slices. The resultant power density inside the target reaches above 50 MV/cm³. Numerical simulation for thermo-mechanical analysis has been performed using PHITS and ANSYS for single and multi-slice targets. Also, empirical test was made using 70-keV electron beam for a single-slice rotation target with the thickness of 0.2 mm. The results of simulation and e-beam tests will be presented.
* Work supported by Rare Isotope Science Program (RISP) through the National Research Foundation of Korea (NRF) funded by Ministry of Science, ICT and Future Planning (MSIP) (2011-0032011)

THPFI042

Design Considerations for Phase Reference Distribution System at ESS

linac, controls, LLRF, cavity

3379

R. Zeng
ESS, Lund, Sweden
A.J. Johansson
Lund University, Lund, Sweden

PRDS (Phase Reference Distribution System) will be serving as the phase alignment line for all cavities with high phase stability. With the current design of individually RF source powering for most cavities at ESS, phase reference distribution system should provide the reference signals for totally 34 LLRF systems at 100 meters long low-frequency section (for all 352.21MHz cavities, including RFQ, DTL, bunching cavities and spokes), and for totally 180 LLRF systems at 342 meters long high-frequency section (for all 704.42MHz cavities, including medium beta and high beta elliptical cavities). Coaxial cable based solution and optical fibre based solution are discussed in this note for PRDS (Phase reference distribution system) at ESS. Some possible schemes in each of these two distribution solutions are introduced and comparisons among these schemes are made. Some effort is made as well to find out a reasonable design for PRDS at ESS.

THPFI047

Design Guidelines for Ferrite Absorbers Submitted to RF-induced Heating

damping, HOM, pick-up, FEL

3394

A. Bertarelli, M. Garlaschè
CERN, Geneva, Switzerland

The use of ferrite absorbers is one of the most effective means of damping potentially harmful high order RF modes, which may lead to beam instabilities and excessive power losses in accelerator devices. However, the power deposited on ferrite absorbers themselves may lead to ferrite exceeding its Curie temperature, losing its damping properties. An evaluation of the ferrite capability to dissipate deposited heat is hence of paramount importance for the safe design of particle accelerator devices. In this paper, figures of merit are proposed to assess the maximum specific power allowed on a generic ferrite tile, before it reaches its Curie temperature. Due to its inherent brittleness, sufficient contact pressure between ferrite and its housing, allowing heat transmission by conduction, can hardly be applied. A semi-analytical study is thus performed, assuming that ferrite is evacuating heat solely through radiation. The described method is then exemplified in the case of the BPM-embedded tertiary collimator (TCTP) designed in the framework of the LHC collimation upgrade.

THPFI050

Some Ideas Towards Energy Optimization at CERN

vacuum, proton, controls, secondary-beams

3400

H.J. Burckhart, J.-P. Burnet, F. Caspers, V. Doré, L. Gatignon, C. Martel, M. Nonis, D. Tommasini
CERN, Geneva, Switzerland

The paper presents the efforts of CERN to optimize its energy usage. Work is proceeding in 3 areas: accelerators, campus and infrastructure, and re-use of thermal “waste” energy. The accelerator chain has the potential to further reduce the energy consumption by dynamic suppression of cycles when they are temporarily not needed and by operating magnets in pulsed mode. R&D for future accelerators includes the recuperation of the RF energy, which is not used for acceleration of the beams. Concerning the CERN campus more than half of the buildings are older than 40 years. Hence there is a big need for renovation, which includes energy aspects. New buildings use renewable energy whenever possible. As an example a building is under construction, which will use a 250 m2 solar field together with an absorption refrigerator for cooling purposes. Finally, about 80% of the electric energy gets dissipated in air cooling towers. Part of this energy can be re-used for heating buildings.

THPFI055

First Year of Operations in the HiRadMat Irradiation Facility at CERN

proton, target, laser, instrumentation

3415

A. Fabich, N. Charitonidis, N. Conan, K. Cornelis, D. DePaoli, I. Efthymiopoulos, S. Evrard, H. Gaillard, J.L. Grenard, M. Lazzaroni, A. Pardons, Y.D.R. Seraphin, C. Theis, K. Weiss
CERN, Geneva, Switzerland
N. Charitonidis
EPFL, Lausanne, Switzerland

HiRadMat (High Irradiation to Materials) is a new facility at CERN constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of 7.2 μs, to maximum pulse energy of 3.4MJ. For 2012, the first year of operations of the facility, nine experiments were scheduled and completed data-taking successfully. The experience gained in operating this unique facility, along with highlights of the experiments and the instrumentation developed for online measurements are reported.

THPFI057

Development of Vacuum Chamber in Low Z Material

vacuum, impedance, background, coupling

3421

C. Garion, P. Costa Pinto, M.A. Gallilee, J. Perez Espinos
CERN, Geneva, Switzerland

Highly transparent vacuum chambers are more and more required in high energy particle physics. In particular, vacuum chambers in the experiments should be as transparent as possible to minimize the background to the detectors while reducing also the material activation. Beryllium is, so far, the most performing material for this application, but it presents some drawbacks such as brittleness, manufacturing issues, toxic hazard, high cost and low availability. A development work to obtain alternative material to the beryllium with similar performance is being carried out at CERN. Three categories have been defined and considered: raw bulk material, material and structural composites. Main requirements are the vacuum compatibility: leak tightness, low outgassing rate, temperature resistance (in the range 200-230 °C), transparency, and mechanical stiffness and strength. Carbon is the element with the lowest atomic number after beryllium and that is appropriate for this application. Therefore carbon based materials have been considered in a variety of options. In this paper, several technologies are presented and discussed. Results of preliminary tests on samples are also shown.

THPFI060

Development, Validation and Application of a Novel Method for Estimating the Thermal Conductance of Critical Interfaces in the Jaws of the LHC Collimation System

collimation, pick-up, target, luminosity

3430

I. Leitão
CERN, Geneva, Switzerland

The motivation for this project arises from the difficulty in quantifying the manufacturing quality of critical interfaces in the water cooled jaws of the TCTP and TCSP (Target Collimator Tertiary Pickup and Target Collimator Secondary Pickup) collimators. These interfaces play a decisive role in the transfer of heat deposited by the beam towards the cooling system avoiding excessive deformation of the collimator. Therefore, it was necessary to develop a non-destructive method that provides an estimation of the thermal conductance during the acceptance test of the TCTP and TCSP jaws. The method is based on experimental measurements of temperature evolution and numerical simulations. By matching experimental and numerical results it is possible to estimate the thermal conductance in several sections of the jaw. A simplified experimental installation was built to validate the method, then a fully automatic Test-Bench was developed and built for the future acceptance of the TCTP/TCSP jaws which will be manufactured and installed in the LHC. This novel method has shown its validity and has become a decisive tool for the development of the new generation of LHC collimators.

THPFI069

Power Saving Status in the NSRRC

controls, synchrotron, synchrotron-radiation, status

3457

J.-C. Chang, Y.F. Chiu, Y.-C. Chung, C.W. Hsu, Y.-C. Lin, C.Y. Liu, Z.-D. Tsai, T.-S. Ueng
NSRRC, Hsinchu, Taiwan

National Synchrotron Radiation Research Center (NSRRC), Taiwan will complete the construction of the civil and utility system engineering of the Taiwan Photon Source (TPS) in the mid of 2013. The power consumption of the TPS is estimated about 2.3 times of that of the existing Taiwan Light Source (TLS). To cope with increasing power requirement in the near future, we have been conducting several power saving schemes, which include power requirement control, optimization of chillers operation, air conditioning system improvement, power factor improvement, application of heat pump, and publishing monthly power saving report. We will also connect the main pipes of TLS and TPS chilled water systems to obtain more efficient operation in 2013.

THPFI072

Heat Transfer Analysis of a Water-cooled Channel for the TPS Front End Components

simulation, synchrotron, synchrotron-radiation, insertion

3466

C.K. Kuan, J.-R. Chen, Y.T. Cheng, J.Y. Chuang, H.Y. Lin, P.A. Lin, Y.K. Liu, I.C. Sheng, T.C. Tseng
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

The masks, absorbers and slits must withstand the extremely high power and power density in the TPS front end. The material always used is OFHC or Glidcop. One solution is to increase the cooling efficiency of the water-cooled channel in these components. With the restrictions of water pressure < 7 kg/cm² and water flow velocity < 3 m/s, the wire coil is chosen to enhance the average heat- transfer coefficient and increase not too much the loss of water pressure. With a water channel of diameter 7.5 mm and wire coil inserts of pitch 7.5 mm and wire diameter 1 mm, the cooling efficiency becomes enhanced 1.4 to 2 times in the components of the TPS front end. The wire coils of varied pitches are simulated and calculated in this work. We also compare our investigated data with other experimental data of other authors.

THPFI080

NSC KIPT Neutron Source on the Base of Subcritical Assembly Driven with Electron Linear Accelerator

neutron, target, electron, klystron

3481

A.Y. Zelinsky, O. Bezditko, P.O. Demchenko, I.M. Karnaukhov, V. Oleinik, F.A. Peev, I. Ushakov, O.M. Vodin
NSC/KIPT, Kharkov, Ukraine
Y. Gohar
ANL, Argonne, USA

National Science Center “Kharkov Institute of Physics and Technology” (NSC KIPT, Kharkov, Ukraine) together with Argonne National Laboratory (ANL, USA) develops the conceptual project of a neutron source based on the sub-critical assembly driven by electron linear accelerator. The main functions of the subcritical assembly are support of the nuclear industry and medical researches. Reactor physics and material researchs will be carried out at the facility. For subcritical assembly design proven techniques and practices are used to enhance its utilization. The goal of the development is to create in Ukraine the experimental basis for neutron research based on safe intensive sources of neutrons. The main facility components are an electron linear accelerator, a system for electron beam transportation from linear accelerator to the target, neutron production target, subcritical assembly, biological shield, neutron channels and auxiliary supporting systems.

THPFI082

Targetry Challenges at Megawatt Proton Accelerator Facilities

target, proton, simulation, kaon

3484

P. Hurh, K. Ammigan, B.D. Hartsell, R.S. Tschirhart
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.
High intensity, multi-megawatt proton accelerator facilities, such as the proposed Project X at Fermilab, offer the opportunity to explore science in multiple experiments and programs simultaneously. The reliable operation of the associated target facilities is as critical to the success of the experimental program as the high intensity proton accelerator itself. The targetry requirements for the Project X experimental program range from 1 GeV, 1 MW, CW proton beam on a high-Z target (possibly liquid metal) to 120 GeV, 2.3 MW, pulsed proton beam on a low-Z target and include stringent, experiment-specific operating environments such as high magnetic fields from super-conducting magnets and/or moderator arrays for optimal neutronic production. Meeting the challenges presented by such wide-ranging and intertwined requirements calls for coordinated and cross-cutting R&D activities. Areas of interest applicable to many of the experimental facilities includes radiation damage, thermal shock, radiological protection, and target instrumentation. Descriptions of these challenges and Fermilab R&D activities to overcome these difficult challenges are presented.

THPFI083

Radiation Damage Study of Graphite and Carbon-carbon Composite Target Materials

target, proton, linac, isotope-production

3487

P. Hurh, K. Ammigan, N.V. Mokhov
Fermilab, Batavia, USA
N. Simos
BNL, Upton, Long Island, New York, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy.
Use of graphite and carbon-carbon composite materials as high intensity proton targets for neutrino production is currently thought to be limited by thermal and structural material properties degraded by exposure to high energy proton beam. Identification of these limits for various irradiation and thermal environments is critical to high intensity targets for future facilities and experiments. To this end, several types of amorphous graphite and one type of carbon-carbon (3D weave) composite were exposed to 180 MeV proton beam at the BNL BLIP facility. Irradiated samples were then thermally, ultra-sonic, and structurally tested and compared to un-irradiated samples. Results show significant changes in material properties even at very low damage levels (<0.09 DPA) and that significant interstitial annealing of these properties occurs at annealing temperatures only slightly above irradiation temperature. This points the way to optimizing target operating temperature to increase target lifetime. A description of the plan to explore radiation damage in target materials through the new RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) is also presented.

THPFI085

Status of PXIE MEBT Absorber Development

electron, vacuum, simulation, gun

3490

A.V. Shemyakin, C.M. Baffes, K. Carlson, A.Z. Chen, Y.I. Eidelman, B.M. Hanna, L.R. Prost, J.T. Walton
Fermilab, Batavia, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
One of the goals of the Project X Injector Experiment (PXIE) at Fermilab is to demonstrate the capability to form an arbitrary bunch pattern from an initially CW 162.5 MHz H⁻ bunch train coming out of an RFQ. The bunch-by-bunch selection will be taking place in the 2.1 MeV Medium Energy Beam Transport (MEBT) by directing the undesired bunches onto an absorber that needs to withstand a beam power of up to 21 kW, focused onto a spot with a ~2 mm rms radius. A ¼ - size prototype of the absorber is manufactured, and its thermal properties are tested with an electron beam generating a peak power density similar to the one expected during normal operation of the PXIE beam line. The paper describes the absorber concept, the prototype, the testing procedure with the electron beam, and the latest results.

THPME020

Design of a Test Cryomodule for IMP ADS-Injector II

cavity, solenoid, cryomodule, vacuum

3546

L. Wang, Y. Liu, S. Sun, J. Wang, S.Y. Wang, S.H. Wang
SINAP, Shanghai, People's Republic of China
X.L. Guo
JiangShu University, Jiangsu Province, People's Republic of China

Two cryomodules are to be applied for the Injector II of the Accelerator Driven Sub-critical System. Each of them will contain 8 superconducting HWR cavities and 9 superconducting solenoids. In order to test the performance of the HWR cavities and validate related technique for cooling of cavities and solenoids together, a test cryomodule (TCM1) including one HWR cavity and two solenoids was developed. The design of the TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics, CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from 100 K to 120 K is required to avoid degrading of the cavity performance. Before energization, the solenoids can be warmed up to above 10 K and re-cooled down for degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. The main components of the cryostat include vacuum chamber, thermal shields, magnet current leads, cooling circuit, and cold mass support assembly. This paper presents the detailed design of the TCM1 cryostat.

THPME024

Magnet Designs of the In-flight Fragment Separator for the RISP

quadrupole, dipole, sextupole, target

3555

D.G. Kim, J.Y. Kim, J.-W. Kim, M. Kim, M. Kim, C.C. Yun, A. Zaghloul
IBS, Daejeon, Republic of Korea

Magnets to be used for the in-flight fragment separator of the rare isotope science project (RISP) have been designed. The dipole magnets have a gap width of 150 mm and a magnetic rigidity of 10 Tm. The superferric quadrupole magnets have a pole tip radius of 170 mm and a maximum field gradient of 14 T/m. In addition, superconducting multiple coils will be wound around the cold bore tube of the quadrupole magnet to make high-order magnetic field corrections. In the high radiation region near the production target, warm iron dipole and quadrupole magnets employing high temperature superconductor (HTS) coils will be used in order to reduce the cold mass and to remove large radiation heat loads effectively at the temperature of 30-50 K. The design of dipole and quadrupole magnets has been optimized considering technical constraints and the manufacturing of the prototype of superferric quadrupole magnets is in progress. Simulation results using OPERA-3D and some results of prototyping will be presented.

THPME026

First Results of the PAL-XFEL Prototype Undulator Measurements

undulator, FEL, controls, insertion-device

3561

D.E. Kim, H.S. Han, Y.-G. Jung, H.-G. Lee, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea
M.-H. Cho, I.S. Ko
POSTECH, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) is developing 10 GeV, 0.1 nm SASE based FEL for high power, short pulse X-ray coherent photon sources named PAL-XFEL. At the first stage PAL-XFEL needs two undulator lines for photon source. PAL is developing undulator magnetic structure based on EU-XFEL design. The hard X-ray undulator features 7.2 mm min magnetic gap, and 5.0 m magnetic length with maximum effective magnetic field larger than 0.908 T to achieve 0.1nm radiation at 10 GeV electron energy. A prototype for PAL-XFEL Xray undulator line is completed and the measurement, correction results are summarized.

THPME027

Design and Fabrication of Prototype Phase Shifter for PAL XFEL

undulator, FEL, electron, controls

3564

H.-G. Lee, Y.-G. Jung, H.-S. Kang, D.E. Kim, S.B. Lee, W.W. Lee, K.-H. Park, H.S. Suh
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory(PAL) is developing a SASE X-ray Free Electron Laser based on 10 GeV linear accelerator. Prototype phase shifters are being developed to be used for the X-ray and Soft X-ray undulator line. The phase shifters will be used to adjust the phase of the electron beam with respect to that of the radiation field. Two prototype phase shifters are being developed. One is based on the EU-XFEL phase shifter using zero-potential iron yoke, and the other one is similar to FERMI phase shifter where only permanent magnets are used. Driving system consists of 5 phase stepping motor, left/right handed ball screw and absolute linear encoder. In this paper, we describe the design, fabrication and test results of the two phase shifter prototypes.

THPME045

TEST RESULTS OF A NB3SN QUADRUPOLE COIL IMPREGNATED WITH RADIATION-RESISTANT MATRIMID 5292

quadrupole, dipole, collider, controls

3612

A.V. Zlobin, G. Ambrosio, N. Andreev, E.Z. Barzi, R. Bossert, G. Chlachidze, V.V. Kashikhin, S. Krave, A. Nobrega, I. Novitski
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
FNAL is developing advanced Nb3Sn magnets for present and future accelerators. Insulation is one of the primary elements of magnet design, essential for maintaining its electrical, mechanical and thermal performance. The Nb3Sn magnet fabrication process involves coil reaction at high temperature and then impregnation with epoxy to restore the insulation electrical and mechanical properties. The traditional epoxy offers adequate structural and electrical properties, but has a low radiation strength which limits the lifetime of accelerator magnets operating in severe radiation environments. Studies to replace epoxy as impregnation material for Nb3Sn coils with high radiation-resistant material have started at FNAL ten years ago. The studies concentrated on the Matrimid® 5292, a bismaleimide based material, which has appropriate viscosity and potlife as well as provides excellent mechanical, electrical and thermal coil properties. A 1 m long Nb3Sn quadrupole coil was recently fabricated, impregnated with Matrimid and tested in a quadrupole magnetic mirror at 4.2 and 1.9 K. Coil test results are presented and compared to the results for similar coils impregnated with epoxy.

THPME048

Assembly and Test of a Modified Spectrometer Solenoid for MICE

solenoid, target, controls, coupling

3621

S.P. Virostek, D. Li, P. Pan, S. Prestemon
LBNL, Berkeley, California, USA
R. Preece
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

Funding: This work is supported by the Office of Science, US-DOE under DOE contract DE-AC02-05CH11231.
The MICE superconducting spectrometer solenoids have been modified and rebuilt as a result of the testing done in 2008, 2009 and 2010. The number of two-stage cryocoolers was increased from three in 2009 to five in the modified magnet. The new shield for the spectrometer solenoid is fabricated primarily from 1100-O aluminum instead of 6061-T6 aluminum used in the former versions of the magnet. The thermal connection between the shield and the first-stage of the cold heads has been improved to reduce the temperature drop between the shield and the coolers. As a result of these changes, the first-stage temperatures for the coolers are below 45K, which resulted in an increase in the refrigeration generated by the cooler second stages. The quench protection system has been altered in order to provide additional protection to the magnet in the event of a lead failure between the magnet power supply and the magnet coils. The quality of the shield and cold mass MLI wrap has also been improved. Details of the modifications and test results demonstrating improved magnet performance are presented in this paper.

THPWA016

Design and Optimization of the Target in Electron Linear Accelerator

target, electron, simulation, photon

3663

Q. Gao, H.B. Chen, J. Shi, H. Zha
TUB, Beijing, People's Republic of China

The target in electron linear accelerator plays an important role in the production of photon. Different materials and thickness of target have influence on dose rate. For 6MeV electron beam, this study gives the thickness of target for several materials in which the dose rate can be higher and drain electron can be lower. Then a X-ray target had been designed for 6MeV electron linac by FLUKA simulations. It can deliver 1000 cGy/min at 1 meter in front of the target if providing 6 MeV electron beam with 100uA current, which can achieve high-dose rate radiotherapy.

THPWA018

High Power Test of a C-band 6 MeV Standing-wave Linear Accelerator

target, coupling, brightness, gun

3666

J.H. Shao, H.B. Chen, Y.-C. Du, Q.X. Jin, J. Shi, H. Zha
TUB, Beijing, People's Republic of China

A C-band 6MeV standing-wave bi-periodic on-axis coupled linear accelerator has been developed at the accelerator laboratory of Tsinghua University [1,2]. In the recent high power RF test, the capture ratio, the energy spectrum, the spot size and the dose rate of this accelerator have been measured. With a 2.07-MW input power, the peak current is 130mA and the output spot root-mean-square diameter is about 0.8mm. The output kinetic energy is 6.0MeV with a spectrum FWHM of 7.5%. In this paper, the setup and detailed results of the high power RF test are presented.

THPWA019

THEORY RESEARCH ON APPLICATION OF CT TECHNOLOGY TO SHIELDED NUCLEAR MATERIAL DISCRIMINATION

electron, neutron, resonance, factory

3669

Y. Zhang, H.B. Chen, Q. Gao, J. Shi
TUB, Beijing, People's Republic of China

Smuggling of nuclear material is a serious threat to security of international society. Formal research on nuclear material discrimination can fulfil customs inspection requirement. This paper designs a situation that nuclear material which is packaged and shielded by heavy metal need to be discriminated accurately on the condition that the object being detected cannot be dismantled. Calculation results prove nuclear material could be discriminated accurately while the ideal condition is fulfilled. If multi-energy X-ray source is used the discrimination accuracy is declined. However the accuracy could be improved while energy spectrum shaping technique is used.

THPWA022

An 800kV 30mA Line-Frequency Cockcroft-Walton Dc Generator Using Gas Insulated Transformer for Radiation Application

high-voltage, electron, power-supply, impedance

3675

Y.H. Liu, H.L. Guo, Z.-F. He, D.M. Li, M.X. Li, W.G. Shi, H.J. Su, S.L. Wang, Y.J. Yang, J.L. Zhang, Y.-T. Zhang
SINAP, Shanghai, People's Republic of China

The design and construction of a line-frequency 800 kV Cockcroft-Walton DC generator using gas insulated transformers are described, as well as the motive to develop it into radiation application. Several features are underlined, preliminary test results of the prototype presented and some problems encountered discussed.

THPWA027

Evaluation of Zero-failure Data in Transient Ionizing Radiation Based on Ordering Method in the Sample Space

laser, target, simulation, electron

3681

X.Y. Bai, X.M. Jin, R.B. Li, Y. Liu, Q. Ma, Ch. Qi
NINT, Xi'an, People's Republic of China

The conventional method for the evaluation of data in lot acceptance testing (LAT) of transient ionizing radiation is non-parametric method. But the evaluation results are very conservative. After the discovery of data in transient ionizing radiation belonging to one universal data model “case 1 interval censored data”, ordering method in the sample space was introduced and applied to evaluate zero-failure data and was compared with non-parametric method both theoretically and via a practical LAT on QG-Ⅰ. Through the comparisons, it is concluded that ordering method can expand the scope of dose rate corresponding to the same lower confidence limit. It improves data utilization and this improvement could have practical significance in LAT. It can reduce requirements for the radiation source and can also reduce the number of trials.

THPWA028

Analysis of Uncertainty of Dose Rate Measurement on the Accelerator “QiangGuang-I”

photon, factory, electron, target

3684

R.B. Li, X.Y. Bai, X.M. Jin, Q. Ma, C. Qi, G.Z. Wang
NINT, Xi'an, People's Republic of China

“QiangGuang-I”, working on short pulse state, can be used to research the transient radiation effects on electronic devices. The measurement of dose rate is significant for assessing devices’ radiation-resistant ability. This paper comprehensively analyzes the originations of uncertainty on dose rate’s measurement, such as thermoluminescent dosemeter’s linearity degree and response to X-rays energy spectrum, testing instruments’ resolution, waveforms’ transmission distortion , and positional error; figures out the extended uncertainty. The result shows that the expanded uncertainty of dose rate’s measurement is less than 20%, which is satisfactory for researching on devices’ transient radiation effects, and proves that the method used to measure dose rate is reasonable.

THPWA029

Transient Ionizing Radiation Effect of Bipolar Operational Amplifiers to Pulsed X-rays

electron, controls, feedback, injection

3687

X.M. Jin
Xiaoming Jin, People's Republic of China
X.Y. Bai, R.B. Li, D.S. Lin, Q. Ma, C. Qi, G.Z. Wang, S.C. Yang
NINT, Xi'an, People's Republic of China

Abstract – The pulsed ionizing radiation effect of monolithic operational amplifiers is investigated using a flash X-ray facility. The experimental results show that the pulsed ionizing radiation produces voltage surges in the devices and the output voltage recovers linearly after transient disturbance which includes a negative peak and a positive peak. The recovery time depends on the amplitude of the positive peak and the inherent slew rate of the devices. The degradation of transient disturbance amplitude and the recovery time versus ionizing dose rate of pulsed X-rays is researched. The relationship of circuit effects to physical mechanisms is investigated in detail. The photocurrent induced by transient ionizing radiation in the PN junctions in integrated circuits is responsible for the electrical degradation. Keywords – Transient ionizing Radiation effect, Transient disturbance, Photocurrent, integrated circuits

THPWA032

Fields of Charged Particle Bunches in Chiral Isotropic Medium

electromagnetic-fields, polarization, vacuum, factory

3696

S.N. Galyamin, A.A. Peshkov, A.V. Tyukhtin
Saint-Petersburg State University, Russia

Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.

THPWA033

Material Discrimination Technology for Cargo Inspection with Pulse-to-pulse Linear Electron Accelerator

electron, controls, collimation, target

3699

S. Ogorodnikov, R. Apevalov, M. Arlychev, I. Polevchenko, A. Rodionov, I.E. Shevelev
Scantronic Systems, St. Petersburg, Russia

In the present article a complex of technological solutions based on 6/3.5 MeV pulse-to-pulse linear accelerator, detectors made of CWO scintillators coupled with PIN photodiodes and image processing algorithms proposed. Energies, dose rate and other parameters of accelerator were optimized to reach high performance of the x-ray system and to carry out robust and reliable material discrimination in the mass thickness range up to 120 g/cm² at least. Evaluation of effective atomic number of materials of main three groups (organics, mineral/light metals, metals) was fulfilled with preciseness ±1 for the optimal mass thickness range at the scanning speed 60 cm/s. Instrument for evaluation of physical mass of the separate objects on the image is proposed and realized.

THPWA035

Intervention Management from Operation to Shutdown

controls, feedback, site, cryogenics

3705

C. Garino, B. Daudin, J. De Jonghe, A. Dorsival, F. B. Dos Santos Pedrosa, G. Dumont, K. Foraz, E.R.F. Reguero Fuentes
CERN, Geneva, Switzerland

The Intervention Management Planning and Coordination Tool (IMPACT) is now widely used in all the accelerator complex and beyond. This unique repository improves the availability of the intervention information for all facilities, and enhances its traceability. It supports a standardized approval workflow and direct link to the access system for improved control and productivity. IMPACT currently has 1418 active users who have defined 6880 intervention requests in 2012 so far. In 2013, the CERN Accelerator complex will enter a shutdown mode after a long period of operation. Careful preparation and scheduling of activities is paramount in order to keep the shutdown as short as possible, whilst guaranteeing safety. During execution, strict control of access will be enforced considering the radiation levels. This paper will summarize the main improvements to IMPACT in this context: work dose planning with respect to ALARA principles including integration with the operational dosimetry system and automatic generation of safety documents from intervention data.

THPWA046

Accelerator Optimization within the oPAC Project

linac, cryogenics, simulation, electron

3735

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by the EU under Grant Agreement 289485.
Many of the today’s most advanced research infrastructures rely on the use of particle accelerators. This includes for example synchrotron light sources and FELs, high intensity hadron accelerators for the generation of exotic beams and spallation sources, as well as much smaller accelerator facilities for precision experiments and fundamental studies. Moreover, accelerators are very important for many commercial applications, such as for example medical applications, material studies and treatment, lithography, or security applications, such as scanners at airports or cargo stations. The full potential of any accelerator can only be exploited if the performance of all its parts are continuously optimized, if numerical tools are made available that allow for developing and improving advanced machine designs, if methods are developed in partnership between the academic and industry sectors to monitor beams with ever higher intensities and brightness, shorter pulse lengths or smaller dimensions. This contribution presents the R&D program of the oPAC project that optimizes existing and future accelerators.

THPWA048

New Generation X-band Linacs for Medical and Industrial Appplications

linac, electron, RF-structure, beam-losses

3741

A.V. Mishin, S. Proskin
RMX, North Andover, USA

The proposed designs of the new X-band linear accelerators for industrial and medical applications are based on a well-known side-coupled RF structure. The immediate applications envisioned for the new linear accelerators are security screening and intraoperative radiotherapy (IORT). The new design has promising features and presents cost reduction potential for electron beam and X-ray systems used in medical, industrial, and security screening applications.

THPWA051

Compact, Inexpensive X-band Linacs as Radioactive Isotope Source Replacements

linac, gun, electron, simulation

3746

S. Boucher, R.B. Agustsson, L. Faillace, J.J. Hartzell, A.Y. Murokh, A.V. Smirnov, S. Storms, K.E. Woods
RadiaBeam, Santa Monica, USA

Funding: Work supported by DNDO Phase II SBIR HSHQDC-10-C-00148 and DOE Phase II SBIR DE- SC0000865.
Radioisotope sources are commonly used in a variety of industrial and medical applications. The US National Research Council has identified as a priority the replacement of high-activity sources with alternative technologies, due to the risk of accidents and diversion by terrorists for use in Radiological Dispersal Devices (“dirty bombs”). RadiaBeam Technologies is developing novel, compact, inexpensive linear accelerators for use in a variety of such applications as cost-effective replacements. The technology is based on the MicroLinac (originally developed at SLAC), an X-band linear accelerator powered by an inexpensive and commonly available magnetron. Prototypes are currently under construction. This paper will describe the design, engineering, fabrication and testing of these linacs at RadiaBeam. Future development plans will also be discussed.

THPWO029

Beam Loss Monitoring and Mitigation at J-PARC DTL

DTL, linac, injection, vacuum

3824

T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Futatsukawa, M. Ikegami, T. Miyao
KEK, Ibaraki, Japan
T. Ito, A. Miura
JAEA/J-PARC, Tokai-mura, Japan

Close radiation survey at the cavity outer surface has indicated a significant beam loss in the first tank of J-PARC DTL (Drift Tube Linac) which has been localized at a certain drift tube. It has motivated us to measure the beam loss at the DTL, and we have installed beam loss monitors of scintillator type at the cavity surface. It is challenging to monitor the beam loss due to low energy of lost particles and shielding by the thick cavity wall. In this paper, we report the results of beam loss measurement and beam loss mitigation tuning using the beam loss monitors.

THPWO030

Recent Progress in Beam Commissioning of J-PARC Linac

linac, DTL, resonance, simulation

3827

M. Ikegami, Z. Fang, K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
A. Miura, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan

The beam operation of J-PARC linac has been restored from the earthquake, and started to pursue higher beam power operation. We have also started to prepare for coming energy and intensity upgrade. In this paper, we review recent progress in beam commissioning of J-PARC linac with emphasis on the beam loss mitigation and preparation for the upgrade.

THPWO075

Beam Loss Limits in High Power Proton Linear Accelerators

proton, rfq, DTL, linac

3930

L. Tchelidze
ESS, Lund, Sweden
J. Stovall
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

High power hadron linear accelerators are designed based on 1 W/m loss limit criteria. The loss limit originates from the hands-on-maintenance allowance of the accelerators and limits average dose rate level to less than 0.1 - 1 mSv/hr at 30 cm from a machine after 100 days of continuous operation and 4 hours of down time. However, machine activation and thus beam loss limit depends on incident particle energy and 1 W/m is only a good approximation for energies 100-200 MeV and higher (in H-/H⁺ accelerators). At lower energies though, one could allow much higher than 1 W/m without excess activation. A careful analysis of energy dependent loss limits was performed for proton linacs as part of the study for the European Spallation Source (ESS) linac, for energy ranges 5 MeV – 2.5 GeV. ESS linac is to be built in Lund, Sweden and will deliver 5 MW proton beam to the target. MARS code was used for calculations and beam loss limits were derived as a function of energy.

FRYAA01

An Overview of Light Source Development in Asia

synchrotron, FEL, electron, linac

4005

D. Wang
SINAP, Shanghai, People's Republic of China

This talk should cover the history of light sources that have been constructed, are now in operation or planned for the future in Asia. Advances in accelerator physics and technological innovations leading to steadily increasing machine performance and photon beam properties should be discussed.

Slides FRYAA01 [7.342 MB]