MOPLB —  Poster Orals   (10-Sep-12   14:50—15:50)

Paper	Title	Page
MOPLB01	Emittance Control for Different FACET Beam Setups in the SLAC Linac	138
	F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.
	Slides MOPLB01 [0.826 MB]
MOPLB02	Positron Injector Linac Upgrade for SuperKEKB	141
	T. Kamitani, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, T. Higo, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	The KEKB B-factory is under an upgrade construction for the SuperKEKB. To achieve 40 times higher luminosity, the linac is required to inject electrons and positrons with higher intensities (e-: 1 nC → 5 nC, e+: 1 nC → 4 nC) and lower emittances (e-: 300 → 20 μm, e+: 2100 → 10 μm). This paper describes the upgrade scheme of the positron source. A new positron capture section will have larger transverse and energy acceptances by introducing a flux concentrator and large aperture L-band and S-band accelerating structures. Beam line layout and quadrupole focusing system will be rearranged for the enlarged beam acceptance. Beam optics is designed to be compatible for positron and electron beams with different energies and emittances. Pulsed quadrupoles and steering magnets are added for better flexibility in optics and orbit tuning. Parameter optimization of the positron source by optics calculation and particle tracking simulation is described.
	Slides MOPLB02 [0.575 MB]
MOPLB03	Advances in Beam Tests of Dielectric Based Accelerating Structures	144
	A. Kanareykin, S.P. Antipov, J.E. Butler, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA W. Gai ANL, Argonne, USA V. Yakimenko BNL, Upton, Long Island, New York, USA
	Funding: US Department of Energy Diamond is being evaluated as a dielectric material for dielectric loaded accelerating structures. It has a very low microwave loss tangent, high thermal conductivity, and supports high RF breakdown fields. We report on progress in our recent beam tests of the diamond based accelerating structures of the Ka-band and THz frequency ranges. Wakefield breakdown test of a diamond-loaded accelerating structure has been carried out at the ANL/AWA accelerator. The high charge beam from the AWA linac (~70 nC, σz = 2.5 mm) was passed through a rectangular diamond loaded resonator and induce an intense wakefield. A groove is cut on the diamond to enhance the field. Electric fields up to 0.3 GV/m has been detected on the diamond surface to attempt to initiate breakdown. A surface analysis of the diamond has been performed before and after the beam test. Wakefield effects in a 250 GHz planar diamond accelerating structure has been observed at BNL/ATF accelerator as well. We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism.
	Slides MOPLB03 [1.986 MB]
MOPLB04	A 10 MeV L-band Linac for Irradiation Applications in China	147
	G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou IHEP, Beijing, People's Republic of China Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu Institute of High Energy Physics (IHEP), People's Republic of China Z. Li, X. Zhang Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China
	The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.
	Slides MOPLB04 [1.800 MB]
MOPLB05	Applications of Compact Dielectric-Based Accelerators	150
	C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA M.E. Conde, W. Gai, J.G. Power ANL, Argonne, USA
	Important progress on the development of dielectric based accelerators has been made experimentally and theoretically in the past few years. One advantage of dielectric accelerators over the metallic counterparts is its compact size, which may attract some applications in industrial or medical accelerators. In this article, we discuss the design and technologies of dielectric based accelerators toward these needs.
MOPLB06	Fermilab 1.3 GHz Superconducting RF Cavity and Cryomodule Program for Future Linacs	153
	C.M. Ginsburg Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The proposed Project X accelerator and the International Linear Collider are based on superconducting RF technology. As a critical part of this effort, Fermilab has developed an extensive program in 1.3 GHz SRF cavity and cryomodule development. This program includes cavity inspection, surface processing, clean assembly, low-power bare cavity tests and pulsed high-power dressed cavity tests. Well performing cavities have been assembled into cryomodules for pulsed high-power tests and will be tested with beam. In addition, peripheral hardware such as tuners and couplers are under development. The current status and accomplishments of the Fermilab 1.3 GHz activity will be described, as well as the R&D program to extend the existing SRF pulsed operational experience into the CW regime.
	Slides MOPLB06 [1.508 MB]
MOPLB07	Non-destructive Inspections for SC Cavities	156
	Y. Iwashita, Y. Fuwa, M. Hashida, K. Otani, S. Sakabe, S. Tokita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan
	Non-destructive Inspections play important roles to improve yield in production of high-performance SC Cavities. Starting from the high-resolution camera for inspection of the cavity inner surface, high resolution T-map, X-map and eddy current scanner have been developed. We are also investigating radiography to detect small voids inside the Nb EBW seam, where the target resolution is 0.1 mm. We are carrying out radiography tests with X-rays induced from an ultra short pulse intense laser. Recent progress will be presented.
	Slides MOPLB07 [5.810 MB]
MOPLB08	Normal Conducting Deflecting Cavity Development at the Cockcroft Institute	159
	G. Burt, P.K. Ambattu, A.C. Dexter, C. Lingwood, B.J. Woolley Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S.R. Buckley, P. Goudket, C. Hill, P.A. McIntosh, J.W. McKenzie, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom V.A. Dolgashev SLAC, Menlo Park, California, USA A. Grudiev CERN, Geneva, Switzerland R.M. Jones UMAN, Manchester, United Kingdom
	Funding: This work has been supported by STFC and the EU through FP7 EUCARD. Two normal conducting deflecting structures are currently being developed at the Cockcroft Institute, one as a crab cavity for CLIC and one for bunch slice diagnostics on low energy electron beams for EBTF at Daresbury. Each has its own challenges that need overcome. For CLIC the phase and amplitude tolerances are very stringent and hence beamloading effects and wakefields must be minimised. Significant work has been undertook to understand the effect of the couplers on beamloading and the effect of the couplers on the wakefields. For EBTF the difficulty is avoiding the large beam offset caused by the cavities internal deflecting voltage at the low beam energy. Propotypes for both cavities have been manufactured and results will be presented.
	Slides MOPLB08 [1.572 MB]
MOPLB09	Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector	162
	R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro INFN/LNF, Frascati (Roma), Italy A. Mostacci, L. Palumbo URLS, Rome, Italy
	The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.
	Slides MOPLB09 [1.061 MB]
MOPLB10	FRIB Technology Demonstration Cryomodule Test	165
	J. Popielarski, E.C. Bernard, S. Bricker, S. Chouhan, C. Compton, A. Facco, A. Fila, L.L. Harle, M. Hodek, L. Hodges, S. Jones, M. Leitner, D. R. Miller, S.J. Miller, D. Morris, R. Oweiss, J.P. Ozelis, L. Popielarski, K. Saito, N.R. Usher, J. Weisend, Y. Zhang, S. Zhao, Z. Zheng FRIB, East Lansing, USA M. Klaus Technische Universität Dresden, Dresden, Germany
	A Technology Demonstration Cryomodule (TDCM) has been developed for a systems test of technology being developed for FRIB. The TDCM consists of two half wave resonators (HWRs) which have been designed for an optimum velocity of β=v/c=0.53 and a resonant frequency of 322 MHz. The resonators operate at 2 K. A superconducting 9 T solenoid is placed in close proximity to one of the installed HWRs. The 9 T solenoid operates at 4 K. A complete systems test of the cavities, magnets, and all ancillary components is presented in this paper. This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661.
	Slides MOPLB10 [2.530 MB]
MOPLB11	The Upgraded Argonne Wakefield Accelerator Facility (AWA): a Test-Bed for the Development of High Gradient Accelerating Structures and Wakefield Measurements	168
	M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof ANL, Argonne, USA S.P. Antipov, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357. Electron beam driven wakefield acceleration is a bona fide path to reach high gradient acceleration of electrons and positrons. With the goal of demonstrating the feasibility of this concept with realistic parameters, well beyond a proof-of-principle scenario, the AWA Facility is currently undergoing a major upgrade that will enable it to achieve accelerating gradients of hundreds of MV/m and energy gains on the order of 100 MeV per structure. A key aspect of the studies and experiments carried out at the AWA facility is the use of relatively short RF pulses (15 – 25 ns), which is believed to mitigate the risk of breakdown and structure damage. The upgraded facility will utilize long trains of high charge electron bunches to drive wakefields in the microwave range of frequencies (8 to 26 GHz), generating RF pulses with GW power levels.
	Slides MOPLB11 [0.900 MB]
MOPLB12	X-Ray Local Energy Spectrum Measurement on Tsinghua Thomson Scattering X-Ray Source (TTX)	171
	Y.-C. Du, J.F. Hua, W.-H. Huang, C.-X. Tang, L.X. Yan, H. Zha, Z. Zhang TUB, Beijing, People's Republic of China
	Thomson scattering X-ray source, in which the TW laser pulse is scattered by the relativistic electron beam, can provide ultra short, monochromatic, high flux, tunable polarized hard X-ray pulse which is can widely used in physical, chemical and biological process research, ultra-fast phase contrast imaging, and so on. Since the pulse duration of X-ray is as short as picosecond and the flux in one pulse is high, it is difficult to measure the x-ray spectrum. In this paper, we present the X-ray spectrum measurement experiment on Tsinghua Thomson scattering. The preliminary experimental results shows the maximum X-ray energy is about 47 keV, which is agree well with the simulations.
	Slides MOPLB12 [1.311 MB]