IPAC2013 - List of Keywords (cryogenics)

Paper	Title	Other Keywords	Page
MOPEA054	A Review of 14 Years of Operation of Helios2 at SSLS	controls, dipole, microtron, gun	199
	Z.W. Li, M. Breese, E.P. Chew, C. Diao, M. Hua, A.W. Wong SSLS, Singapore, Singapore
	In this paper, we present the current status of the superconducting Helios2 Synchrotron and review its major problems and their solutions over the last 14 years. We described how various breakdowns in the cryogenics system, the control system, the RF system, Dipole power supplies, Ring gate valves and helium compressor have all been overcome and what valuable lessons have been learned in operating this machine.

MOPFI082	Redesign and Development of the Shanghai Electron Beam Ion Trap	electron, ion, vacuum, alignment	467
	D. Lu, Y. Shen, Z. Shi, J. Xiao, Y. Yang, Y. Zou Fudan University, Shanghai, People's Republic of China
	Over the last few years the Shanghai Electron Beam Ion Trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Nuclear and Applied Physics, first generated an electron beam in 2005. Shanghai EBIT could be operated with electron beam energies between 1 and 130 keV and currents up to 160 mAmps. After several years of operation, it was found that some improvements/modifications to the old design were necessary. This contribution will discuss several of the main aspects of the redesigned Shanghai EBIT. So far it has been operated up to an electron energy of 40 keV with an current density of over 2400 A per square cm. The new EBIT is made primarily from Titanium instead of Stainless Steel and has an order of magnitude better background vacuum, a more efficient and economical cryogenic system, and also excellent optical alignment. Finally the magnetic field in the central drift tube region can reach up till 4.8 T.

MOPME013	20 Years of Development of SQUID-based Cryogenic Current Comparator for Beam Diagnostics	pick-up, ion, shielding, niobium	497
	W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany K.K. Knaack, K. Wittenburg DESY, Hamburg, Germany A. Peters HIT, Heidelberg, Germany H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	This contribution gives an overview on the development of highly sensitive SQUID-based Cryogenic Current Comparators (CCC) for nuclear physics from the first successful demonstration of its performance at GSI Darmstadt through the latest improved version for FAIR and the Cryogenic Storage Ring at MPI Heidelberg. An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnosis. Also the measurement of so-called dark currents, generated by super-conductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL at DESY). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems.

MOPME071	Characterisation of Si Detectors for use at 2 Kelvin	proton, radiation, 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.

MOPME072	Performance Tests of a Short Faraday Cup Designed for HIE-ISOLDE	electron, ion, diagnostics, cryomodule	646
	E.D. Cantero, W. Andreazza, E. Bravin, M.A. Fraser, D. Lanaia, A.G. Sosa, D. Voulot CERN, Geneva, Switzerland
	Funding: E.D.C, D.L. and A.S. acknowledge CATHI Marie Curie ITN: EU-FP7-PEOPLE-2010-ITN Project number 264330. M.A.F acknowledges co-funding by the European Commission (Grant agreement PCOFUND-GA-2010-267194) The On-Line Isotope Mass Separator (ISOLDE) facility at CERN is being upgraded in order to deliver higher energy and intensity radioactive beams. The final setup will consist in replacing the energy variable part of the normal conducting REX post-accelerator with superconducting cavities. In order to preserve the beam emittance, the drift space between the cryomodules housing these cavities has been kept to a minimum. As a consequence, the longitudinal space available for beam diagnostics is severely limited in the inter-cryomodule regions. A Faraday cup (FC) will be installed to measure beam currents, and due to the tight spatial constraints, its length is much smaller than usual. This poses a great challenge when trying to avoid the escape of ion-induced secondary electrons, which would falsify the current measurement. Two prototypes of such a short FC have therefore been tested at REX-ISOLDE using several beam intensities and energies, with the aim of determining its accuracy. In this paper the experimental results obtained for the two prototype cups are presented together with numerical calculations of the electrostatic fields that are produced inside the cup.

TUPFI013	LHC Long Shutdown: A Parenthesis for a Challenge	radiation, 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.

TUPME040	TLEP: High-performance Circular e⁺e⁻ Collider to Study the Higgs Boson	polarization, luminosity, collider, wiggler	1658
	M. Koratzinos, O. Brunner, A.C. Butterworth, J.R. Ellis, P. Janot, E. Jensen, J.A. Osborne, F. Zimmermann CERN, Geneva, Switzerland R. Aleksan CEA/DSM/IRFU, France A.P. Blondel DPNC, Genève, Switzerland M. Zanetti MIT, Cambridge, Massachusetts, USA
	The recent discovery of a light Higgs boson has opened up considerable interest in circular e⁺e⁻ Higgs factories around the world. We report on the progress of the “TLEP3” concept since last year. Two options are considered: LEP3, a 240 GeV centre-of-mass (Ecm) e⁺e⁻ machine in the LHC tunnel with cost only a fraction of the cost of an equivalent linear collider, due to the use of existing infrastructure and the two general-purpose LHC detectors, and TLEP, an e⁺e⁻ machine in a new 80 km tunnel that can operate up to an Ecm of 350 GeV. Both concepts enjoy the extensive know-how on circular colliders and how to deliver their design luminosity, and the existence of up to four interaction points. The attainable luminosities are 10³⁴/cm²/s and 5x10³⁴/cm²/s per interaction point for LEP3 and TLEP respectively. Both machines can operate as Tera-Z and Mega-W boson factories, giving decisive opportunities for over-constraining the electroweak sector of the Standard Model. The technical challenges and possible ways to improve the performance further will be discussed.

WEPWA003	Hall-Probe Bench for Cryogenic in-Vacuum-Undulators	undulator, vacuum, laser, permanent-magnet	2126
	C. Kuhn, H.-J. Bäcker, J. Bahrdt, A. Gaupp, B. Schulz HZB, Berlin, Germany
	The Helmholtz-Zentrum Berlin (HZB) builds a 2m long in-vacuum-hall-probe-bench for the characterization of several cryogenic undulators currently under development. Short period lengths and small gaps require an accurate correlation between Hall probe position / orientation and the 3D-magnetic field. The geometric tolerances of an in-vacuum bench in the presence of strong temperature gradients do not permit a Hall probe movement along a straight line without corrections. The HZB-bench employs a system of laser interferometers and position sensitive detectors, which is used in a feed-back loop for the Hall probe position / orientation. First measurements on the accuracy and reproducibility of the new device are presented.

WEPWA028	Measurement and Research on Cryogenic Remanence of Chunks Permanent Magnet for Cryogenic Undulator	permanent-magnet, controls, undulator, factory	2190
	Y.Z. He SINAP, Shanghai, People's Republic of China
	The higher-precision cryogenic remanence measurment technology and error for chunks permanent magnet were researched in china firstly (10-300K). Magnetic measurement tooling and magnetic field calculation and measurement method of cryogenic remanence measurement system of chunks permanent magnet for cryogenic undulator were optimized. Cryogenic calibration Hall probe were pasted on surface of domestic chunks permanent magnet(Nd2Fe14B: N52, N50M, etc.) and table magnetic field B of permanent magnet were measured, and after being converted, then cryogenic remanence of domestic chunks permanent magnet were obtained and cryogenic remanence variation of domestic chunks permanent magnet were researched. Cryogenic remanence measurement data were checked by pulse B-H tester and PPMS respectively, the results show that cryogenic remanence data has higher reliability. By this experiment, initial foundation were established for development of SSRF cryogenic undulator and for cryogenic remanence measurement and study of domestic other chunks permanent magnets.

WEPWA062	Status of the UK Superconducting Planar Undulator Project	undulator, vacuum, wakefield, radiation	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.

WEPWA068	Design Concepts for the NGLS Linac	cavity, linac, cryomodule, HOM	2271
	A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, J. Qiang, M. Venturini, R.P. Wells LBNL, Berkeley, California, USA C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams JLAB, Newport News, Virginia, USA C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov Fermilab, Batavia, USA
	The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time.

WEPWA081	Status of the Praseodymium Undulator with Textured Dysprosium Poles for Compact X-Ray FEL Applications	undulator, vacuum, simulation, radiation	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.

WEPWA086	Characterization of PrFeB Permanent Magnet Blocks with Helmholtz Coils at NSLS-II	undulator, dipole, permanent-magnet, insertion	2304
	P. He, P.L. Cappadoro, T.M. Corwin, H.C. Fernandes, D.A. Harder, C.A. Kitegi, M.M. Musardo, G. Rakowsky, J. Rank, T. Tanabe BNL, Upton, Long Island, New York, USA M. Kokole KYTE, Sezana, Slovenia
	For investigatation to build the cryogenic undulator using bake-able Praseodymium-Iron-Boron(PrFeB) magnet blocks, a short period(16.8mm) and fixed gap(5mm) hybrid undulator prototype has been fabricated at BNL. For this undulator, 36 PrFeB magnet blocks(28 type A, 4 type B, 4 type C) are used. The magnetic field characteristics of the undulator heavily depend on the directional uniformity of the magnetization of block sets. The strength and direction of magnetization of the PrFeB magnet blocks are measured using a Helmholtz coil system. The data include the three vector components of the total magnetic dipole moment of the blocks and also compare with vendor measuremeant results.

WEPWO017	Efforts on Nondestructive Inspections for SC Cavities	cavity, target, laser, SRF	2352
	Y. Iwashita, Y. Fuwa, M. Hashida, S. Sakabe, S. Tokita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan K. Otani INRS-EMT, Varennes (Québec), Canada
	The high resolution camera, so-called Kyoto Camera, inspecting the Sc cavity inner surface showed the importance of nondestructive inspections to improve yield in production of high performance SC Cavities. Further efforts have been continued for the inspection and the high resolution T-map, X-map and eddy current scanner have been developed. A radiography to detect small voids inside the Nb EBW seam with the target resolution of 0.1 mm is under investigation. We have carried out radiography tests with X-rays induced from an ultra short pulse intense laser.

WEPWO036	Conceptual Design of a Superfluid Superconducting Third Harmonic RF System for the SSRF Storage Ring	cavity, superconducting-cavity, controls, synchrotron	2381
	H.T. Hou, J.F. Liu, Z.T. Zhao SINAP, Shanghai, People's Republic of China J.F. Liu Shanghai KEY Laboratory of Cryogenics & Superconducting RF Technology, Shanghai, People's Republic of China
	Harmonic cavity can improve the beam quality through bunch size lengthening which includes providing Landau damping, suppressing coupled bunch instability and microwave instability, enhancing the beam current per bunch besides the beam lifetime improvement. A passive third harmonic superconducting cavity operating at super fluid liquid helium has been proposed for the SSRF storage ring with compromise on the required harmonic voltage, limited installation space and dissipated cryogenic power. This paper will mainly present the conceptual design of the harmonic rf system including the requirement of SSRF, a brief review on beam dynamics of harmonic rf system and the harmonic cavity choice.

WEPWO042	Dubna-Minsk SRF Technology Development Status Report	cavity, niobium, coupling, electron	2393
	N.S. Azaryan, Ju. Boudagov, D.L. Demin, V.V. Glagolev, G. Shirkov, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia M.A. Baturitsky, N.M. Shumeiko NC PHEP BSU, Minsk, Belarus S.E. Demyanov, E.Yu. Kaniukov Scientific-Practical Materials Research Centre of the National Academy of Sciences of Belarus, Minsk, Belarus A. Ermakov, W. Singer, X. Singer DESY, Hamburg, Germany V.A. Karpovich, N.V. Liubetsky BSU, Minsk, Belarus S.V. Kolosov, A.A. Kurayev, A.O. Rak, A.K. Sinitsyn Belarus State University of Informatics and Radioelectronics (BSUIR), Minsk, Belarus S.I. Maximov, V.N. Rodionova Belarussian State University, Scientific Research Institute of Nuclear Problems, Minsk, Belarus A. Parshuto, V.S. Petrakovsky, I.L. Pobol, A.I. Pokrovsky, S.V. Yurevich, A.Yu. Zhuravsky Physical-Technical Institute of the National Academy of Sciences of Belarus, Minsk, Belarus
	In 2011 Dubna-Minsk collaboration started an activity on the development and manufacture the series of 1.3 GHz superconducting Nb cavities in the enterprises in Belarus. The current status of this work is presented in this report. Main EM characteristics of the cavity were calculated and the shop drawings for cavity fabrication were developed. Two test-benches were assembled for RF-tests of the cavities at room temperature and at liquid helium temperature. The measured SWR was about 1.01 due to special matching device developed for that. This measurement technique was applied to the single-cell cavity from FNAL at power level nearby 10 mW. Measured resonant frequency was about 1.27 GHz, while the measured Q-factor was 2.8·10⁴ at room temperature and more than 10⁸ at liquid helium temperature. To evaluate mechanical properties of sheet Nb and of model materials (Cu and Al), a number of tests were made. Series of half-cells were fabricated of Al to test the technique of hydraulic deep-drawing that will be used in production of Nb cavities. The modes for electron-beam welding of sheet Nb were explored and the first welding seams were tested. The method of chemical treatment of cavities was also elaborated.
	Poster WEPWO042 [0.897 MB]

WEPWO076	Development of Ultra High Gradient and High Q0 Superconducting Radio Frequency Cavities	cavity, niobium, SRF, acceleration	2474
	R.L. Geng, W.A. Clemens, J. Follkie, T. Harris, D. Machie, R. Martin, A.D. Palczewski, E. Perry, G. Slack, R.S. Williams JLAB, Newport News, Virginia, USA C. Adolphsen, Z. Li SLAC, Menlo Park, California, USA J.K. Hao, Y.M. Li, K.X. Liu PKU, Beijing, People's Republic of China P. Kushnick JLab, Newport News, Virginia, USA
	Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q0 superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q0 of 10¹⁰ at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q0 of 2·10¹⁰ at 2K. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

THOBB201	Pathway to a Post Processing Increase in Q0 of SRF Cavities	cavity, shielding, niobium, SRF	3129
	O. Kugeler, J. Knobloch, J.M. Vogt HZB, Berlin, Germany S. Aull CERN, Geneva, Switzerland
	A significant improvement of Q0 to values larger than 3.2x10¹⁰ at 1.8K has been repeatedly achieved in an SRF cavity by thermal cycling, i.e. heating the cavity briefly above transition temperature and subsequent cooling. Conceivable explanations for this effect reach from effectivity deviations of the magnetic shielding to thermal currents to hydrogen diffusion. Experimental We have experimentally verified some of these explanations, leaving a direct impact of cooling dynamics on frozen flux as the most plausible one. The pathway to this finding is being presented and the application to SRF systems is elicited.
	Slides THOBB201 [1.184 MB]

THPEA044	Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors	proton, radiation, 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.

THPFI005	Simulations for Mechanical Design of Nozzle for Extrude of Windowless Solid Hydrogen Cryogenic Target	simulation, target, extraction	3297
	H. Gassot, C. Commeaux IPN, Orsay, France
	The hydrogen (H2 and D2) target is the determining element of unstable nucleus spectroscopy. This target is proposed for heavy ions beam of several MeV/nucleon in SPIRAL and SPIRAL 2 projects. Without window, the carbone contamination of the hydrogen target could be avoided. Within the project of CHyMENE (Cible d’Hydrogène Mince pour l’Etude des Noyaux Exotiques), the development of hydrogen target is supported by ANR (Agence National de la Recherche) which federates differents French research institutes such as CNRS and CEA. The IPN Orsay is involved on the conception and simulations of a nozzle which can deliver a solid ribbon of 50 micron thickness; it is a very challenging program since the knowledge about hydrogen solid at 12 K is rare, especially in terms of experimental characterizations. The important work consists at first to propose models of simulations in order to study mechanical behaviours of solid hydrogen at cryogenic temperature under pressure and optimize the geometry parameters as well as rheology properties of nozzle. The mechanical non linear modelling including contact behaviours are presented. The first simulations results are summarized.

THPFI093	Device and Technique for In-situ Coating of the RHIC Cold Bore Vacuum Tubes with Thick OFHC	electron, vacuum, cathode, superconducting-magnet	3508
	A. Hershcovitch, M. Blaskiewicz, J.M. Brennan, W. Fischer, C.J. Liaw, W. Meng, R.J. Todd BNL, Upton, Long Island, New York, USA A.X. Custer, M.Y. Erickson, N.Z. Jamshidi, H.J. Poole PVI, Oxnard, USA J.M. Jimenez, H. Neupert, M. Taborelli, C. Yin Vallgren CERN, Geneva, Switzerland N. Sochugov Institute of High Current Electronics, Tomsk, Russia
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. To mitigate electron clouds & unacceptable ohmic heating problems in RHIC, we developed a robotic plasma deposition technique & device to in-situ coat the RHIC 316LN SS cold bore tubes based on mobile mole mounted magnetrons for OFHC deposition. Scrubbed Cu has low SEY and suppress electron cloud formation. Room temperature RF resistivity measurement of Cu coated SS RHIC tube samples indicate that 10 μm of Cu coating has conductivity close to copper tubing. A 50 cm long copper cathode magnetron, mounted on a carriage with spring loaded wheels, was successfully operated, traversed magnet interconnect bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. To maximize cathode lifetime, Cu cathode thickness was maximized its gap to vacuum tube minimized; movable magnet package is used. Novel cabling and vacuum-atmosphere interface system is being developed. Deposition experiments show no indentation in or damage to coating after wheels roll over coated areas; i.e. train like assembly option is a viable for in-situ RHIC coating. Details of experimental setup & coating of full-scale magnet tube sandwiched between bellows will be presented.

THPME025	Design of Cryomodules for RAON	cryomodule, cavity, linac, vacuum	3558
	Y. Kim, C. Choi, D. Jeon, H.J. Kim, M. Lee IBS, Daejeon, Republic of Korea
	The RAON linac utilizes four types of superconducting cavities such as QWR, HWR, SSR1, and SSR2 which are operating at 2 K in order to accelerate the various ion beams. The main role of the cryomodules is to maintain the cryogenic temperature for the superconducting cavity operation. Five types of cryomodules will be necessary since one QWR cavity, three and six HWR cavities, four SSR1 cavities, and eight SSR2 cavities will be installed in the dedicated cryomdoules. Total number of the cryomodule is 147, 48 for QWR, 60 for HWR, 22 for SSR1, 17 for SSR2. The cryomodules of RAON does not include focusing magnets but includes the cavities operating at 2 K. This paper describes the current status of the RAON cryomodule design. The issues included in the paper are the thermal load estimation, design of the components such as thermal shield and intercept of the cryomodules, and cryogenic flow circulation system according to the cryomodule operation.

THPME034	The LHC Cryogenic Operation Availability Results from the First Physics Run of Three Years	controls, instrumentation, monitoring, collider	3585
	D. Delikaris, K. Brodzinski, S.D. Claudet, G. Ferlin, L.J. Tavian, U. Wagner CERN, Geneva, Switzerland
	The LHC (Large Hadron Collider) accelerator consists in eight cryogenically independent sectors, each 3.3 km long with a cold mass of 4500 ton cooled at 1.9 K. Each helium cryogenic plant combines an 18 kW at 4.5 K refrigerator and a 2.4 kW at 1.8 K refrigeration unit. Since early operation for physics in November 2009, the availability has been above 90% for more than 260 days per year, ending at 94.8% in 2012 and corresponding to an equivalent availability of more than 99% per independent sector. The operation and support methodology as well as the achieved performance results are presented. Emphasis is given on implementing operational return for short, medium and long term consolidations. Perspective for restart after the first long shutdown of the LHC works will be described.

THPME035	The Electronic System Design and Realization for First Set 500 MHz KEKB SRF Module High Power Test	SRF, controls, cavity, HOM	3588
	F.-T. Chung, L.-H. Chang, M.H. Chang, L.J. Chen, M.-C. Lin, Y.-H. Lin, Z.L. Liu, C.H. Lo, M.H. Tsai, Ch. Wang, T.-T. Yang, M.-S. Yeh, T.-C. Yu NSRRC, Hsinchu, Taiwan
	This article reports the home-made electronics circuits for reading the various electronics signals which can be used for site acceptance of superconducting resonant cavity. The adjustment of parameters during 1st SRF high power acceptance can also be used for the update of the 2nd electronics. The modular electronics system will provide the advantages of fast repair, preparing spare parts easily, short install time and flexible adjustment. The hardware whole electronics system is mainly designed by CPLD, PLC and Display meters. The Military Standard connectors are used for signals connection. There are always junction boxes for signal transmission test and convenient signal jumping for ensuring the correct signal source. In safety action, there are Fast Interlock Sum (0-10us) and slow ready chain (50ms-150ms). The complete system realizes the real time monitor and protection of superconducting resonant cavity.

THPME039	The Control System for the Purification Station at NSRRC	controls, monitoring, vacuum, synchrotron	3597
	T.F. Lin, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, C.K. Kuan, H.C. Li, C.P. Liu, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A cryogenic adsorber was used liquid nitrogen to trap the impurities from gaseous helium in the helium cryogenic system. NSRRC parallel connected five cryogenic adsorbers for the cryogenic system in the year 2011; five additional cryogenic adsorbers will be installed in the year 2013. The original design of liquid nitrogen filling was motored and controlled manually to keep the efficiency of the purifying. The regeneration of the cryogenic adsorber must be performed manually as well by using heater and vacuum pump after saturated of the cryogenic adsorber. NSRRC develop one control system that is allowed the liquid nitrogen filling and regeneration process turns into automatically. This paper is aimed to present the construction of the control system. The installation and test results will be included in this paper as well.

THPME040	The Installation and Commissioning of the Helium Cryogenic System for theTPS Project	SRF, storage-ring, electron, controls	3600
	H.H. Tsai, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, C.K. Kuan, H.C. Li, T.F. Lin, C.P. Liu NSRRC, Hsinchu, Taiwan
	The construction of an electron accelerator with energy 3 GeV is under way for high brilliance and flux X-ray photon source at NSRRC. There will be eventually four superconducting radio frequency (SRF) cavities installed to maintain the electron energy. The helium cryogenic system has been designed and fabricated to provide the required liquid helium for SRF cavities. The cryogenic system consists of the 700-W refrigerator, the 315-kW variant frequency compressor, the oil removal system, the recovery compressor system, the gas helium buffer tanks, and one 7000-L liquid helium Dewar. The overall system installation and commissioning will be presented and discussed in this paper.

THPWA035	Intervention Management from Operation to Shutdown	radiation, controls, feedback, site	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, radiation, 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.

THPWO011	Status of the SIS100 Heavy Ion Synchrotron Project at FAIR	dipole, quadrupole, ion, extraction	3782
	P.J. Spiller, U. Blell, O. Boine-Frankenheim, L.H.J. Bozyk, E.S. Fischer, E. Floch, F. Hagenbuck, F. Hehenberger, M. Kauschke, O.K. Kester, A. Klaus, H. Klingbeil, H.G. König, P. Kowina, J.P. Meier, P. Moritz, C. Mühle, C. Omet, D. Ondreka, N. Pyka, H. Ramakers, P. Schnizer, J. Stadlmann, K. Sugita, D. Theuerkauf, B. Walasek-Höhne, St. Wilfert GSI, Darmstadt, Germany
	SIS100 is a unique superconducting heavy ion synchrotron, optimized for the acceleration of intense beams of intermediate charge state heavy ions. The operation with such beams has required new synchrotron design features and new technical concepts aiming for minimized ionization beam loss and vacuum dynamics. SIS100 is a superconducting synchrotron because of the required vacuum conditions and pumping power to achieve stable XHV conditions at high intensity operation. The project and procurement status will be presented.

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MOPEA054

A Review of 14 Years of Operation of Helios2 at SSLS

controls, dipole, microtron, gun

199

Z.W. Li, M. Breese, E.P. Chew, C. Diao, M. Hua, A.W. Wong
SSLS, Singapore, Singapore

In this paper, we present the current status of the superconducting Helios2 Synchrotron and review its major problems and their solutions over the last 14 years. We described how various breakdowns in the cryogenics system, the control system, the RF system, Dipole power supplies, Ring gate valves and helium compressor have all been overcome and what valuable lessons have been learned in operating this machine.

MOPFI082

Redesign and Development of the Shanghai Electron Beam Ion Trap

electron, ion, vacuum, alignment

467

D. Lu, Y. Shen, Z. Shi, J. Xiao, Y. Yang, Y. Zou
Fudan University, Shanghai, People's Republic of China

Over the last few years the Shanghai Electron Beam Ion Trap (EBIT) has been successfully redesigned and rebuilt. The original machine, developed under collaboration with the Shanghai Institute of Nuclear and Applied Physics, first generated an electron beam in 2005. Shanghai EBIT could be operated with electron beam energies between 1 and 130 keV and currents up to 160 mAmps. After several years of operation, it was found that some improvements/modifications to the old design were necessary. This contribution will discuss several of the main aspects of the redesigned Shanghai EBIT. So far it has been operated up to an electron energy of 40 keV with an current density of over 2400 A per square cm. The new EBIT is made primarily from Titanium instead of Stainless Steel and has an order of magnitude better background vacuum, a more efficient and economical cryogenic system, and also excellent optical alignment. Finally the magnetic field in the central drift tube region can reach up till 4.8 T.

MOPME013

20 Years of Development of SQUID-based Cryogenic Current Comparator for Beam Diagnostics

pick-up, ion, shielding, niobium

497

W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
K.K. Knaack, K. Wittenburg
DESY, Hamburg, Germany
A. Peters
HIT, Heidelberg, Germany
H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

This contribution gives an overview on the development of highly sensitive SQUID-based Cryogenic Current Comparators (CCC) for nuclear physics from the first successful demonstration of its performance at GSI Darmstadt through the latest improved version for FAIR and the Cryogenic Storage Ring at MPI Heidelberg. An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnosis. Also the measurement of so-called dark currents, generated by super-conductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL at DESY). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems.

MOPME071

Characterisation of Si Detectors for use at 2 Kelvin

proton, radiation, 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.

MOPME072

Performance Tests of a Short Faraday Cup Designed for HIE-ISOLDE

electron, ion, diagnostics, cryomodule

646

E.D. Cantero, W. Andreazza, E. Bravin, M.A. Fraser, D. Lanaia, A.G. Sosa, D. Voulot
CERN, Geneva, Switzerland

Funding: E.D.C, D.L. and A.S. acknowledge CATHI Marie Curie ITN: EU-FP7-PEOPLE-2010-ITN Project number 264330. M.A.F acknowledges co-funding by the European Commission (Grant agreement PCOFUND-GA-2010-267194)
The On-Line Isotope Mass Separator (ISOLDE) facility at CERN is being upgraded in order to deliver higher energy and intensity radioactive beams. The final setup will consist in replacing the energy variable part of the normal conducting REX post-accelerator with superconducting cavities. In order to preserve the beam emittance, the drift space between the cryomodules housing these cavities has been kept to a minimum. As a consequence, the longitudinal space available for beam diagnostics is severely limited in the inter-cryomodule regions. A Faraday cup (FC) will be installed to measure beam currents, and due to the tight spatial constraints, its length is much smaller than usual. This poses a great challenge when trying to avoid the escape of ion-induced secondary electrons, which would falsify the current measurement. Two prototypes of such a short FC have therefore been tested at REX-ISOLDE using several beam intensities and energies, with the aim of determining its accuracy. In this paper the experimental results obtained for the two prototype cups are presented together with numerical calculations of the electrostatic fields that are produced inside the cup.

TUPFI013

LHC Long Shutdown: A Parenthesis for a Challenge

radiation, 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.

TUPME040

TLEP: High-performance Circular e⁺e⁻ Collider to Study the Higgs Boson

polarization, luminosity, collider, wiggler

1658

M. Koratzinos, O. Brunner, A.C. Butterworth, J.R. Ellis, P. Janot, E. Jensen, J.A. Osborne, F. Zimmermann
CERN, Geneva, Switzerland
R. Aleksan
CEA/DSM/IRFU, France
A.P. Blondel
DPNC, Genève, Switzerland
M. Zanetti
MIT, Cambridge, Massachusetts, USA

The recent discovery of a light Higgs boson has opened up considerable interest in circular e⁺e⁻ Higgs factories around the world. We report on the progress of the “TLEP3” concept since last year. Two options are considered: LEP3, a 240 GeV centre-of-mass (Ecm) e⁺e⁻ machine in the LHC tunnel with cost only a fraction of the cost of an equivalent linear collider, due to the use of existing infrastructure and the two general-purpose LHC detectors, and TLEP, an e⁺e⁻ machine in a new 80 km tunnel that can operate up to an Ecm of 350 GeV. Both concepts enjoy the extensive know-how on circular colliders and how to deliver their design luminosity, and the existence of up to four interaction points. The attainable luminosities are 10³⁴/cm²/s and 5x10³⁴/cm²/s per interaction point for LEP3 and TLEP respectively. Both machines can operate as Tera-Z and Mega-W boson factories, giving decisive opportunities for over-constraining the electroweak sector of the Standard Model. The technical challenges and possible ways to improve the performance further will be discussed.

WEPWA003

Hall-Probe Bench for Cryogenic in-Vacuum-Undulators

undulator, vacuum, laser, permanent-magnet

2126

C. Kuhn, H.-J. Bäcker, J. Bahrdt, A. Gaupp, B. Schulz
HZB, Berlin, Germany

The Helmholtz-Zentrum Berlin (HZB) builds a 2m long in-vacuum-hall-probe-bench for the characterization of several cryogenic undulators currently under development. Short period lengths and small gaps require an accurate correlation between Hall probe position / orientation and the 3D-magnetic field. The geometric tolerances of an in-vacuum bench in the presence of strong temperature gradients do not permit a Hall probe movement along a straight line without corrections. The HZB-bench employs a system of laser interferometers and position sensitive detectors, which is used in a feed-back loop for the Hall probe position / orientation. First measurements on the accuracy and reproducibility of the new device are presented.

WEPWA028

Measurement and Research on Cryogenic Remanence of Chunks Permanent Magnet for Cryogenic Undulator

permanent-magnet, controls, undulator, factory

2190

Y.Z. He
SINAP, Shanghai, People's Republic of China

The higher-precision cryogenic remanence measurment technology and error for chunks permanent magnet were researched in china firstly (10-300K). Magnetic measurement tooling and magnetic field calculation and measurement method of cryogenic remanence measurement system of chunks permanent magnet for cryogenic undulator were optimized. Cryogenic calibration Hall probe were pasted on surface of domestic chunks permanent magnet(Nd2Fe14B: N52, N50M, etc.) and table magnetic field B of permanent magnet were measured, and after being converted, then cryogenic remanence of domestic chunks permanent magnet were obtained and cryogenic remanence variation of domestic chunks permanent magnet were researched. Cryogenic remanence measurement data were checked by pulse B-H tester and PPMS respectively, the results show that cryogenic remanence data has higher reliability. By this experiment, initial foundation were established for development of SSRF cryogenic undulator and for cryogenic remanence measurement and study of domestic other chunks permanent magnets.

WEPWA062

Status of the UK Superconducting Planar Undulator Project

undulator, vacuum, wakefield, radiation

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.

WEPWA068

Design Concepts for the NGLS Linac

cavity, linac, cryomodule, HOM

2271

A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, J. Qiang, M. Venturini, R.P. Wells
LBNL, Berkeley, California, USA
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams
JLAB, Newport News, Virginia, USA
C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov
Fermilab, Batavia, USA

The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time.

WEPWA081

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

undulator, vacuum, simulation, radiation

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.

WEPWA086

Characterization of PrFeB Permanent Magnet Blocks with Helmholtz Coils at NSLS-II

undulator, dipole, permanent-magnet, insertion

2304

P. He, P.L. Cappadoro, T.M. Corwin, H.C. Fernandes, D.A. Harder, C.A. Kitegi, M.M. Musardo, G. Rakowsky, J. Rank, T. Tanabe
BNL, Upton, Long Island, New York, USA
M. Kokole
KYTE, Sezana, Slovenia

For investigatation to build the cryogenic undulator using bake-able Praseodymium-Iron-Boron(PrFeB) magnet blocks, a short period(16.8mm) and fixed gap(5mm) hybrid undulator prototype has been fabricated at BNL. For this undulator, 36 PrFeB magnet blocks(28 type A, 4 type B, 4 type C) are used. The magnetic field characteristics of the undulator heavily depend on the directional uniformity of the magnetization of block sets. The strength and direction of magnetization of the PrFeB magnet blocks are measured using a Helmholtz coil system. The data include the three vector components of the total magnetic dipole moment of the blocks and also compare with vendor measuremeant results.

WEPWO017

Efforts on Nondestructive Inspections for SC Cavities

cavity, target, laser, SRF

2352

Y. Iwashita, Y. Fuwa, M. Hashida, S. Sakabe, S. Tokita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan
K. Otani
INRS-EMT, Varennes (Québec), Canada

The high resolution camera, so-called Kyoto Camera, inspecting the Sc cavity inner surface showed the importance of nondestructive inspections to improve yield in production of high performance SC Cavities. Further efforts have been continued for the inspection and the high resolution T-map, X-map and eddy current scanner have been developed. A radiography to detect small voids inside the Nb EBW seam with the target resolution of 0.1 mm is under investigation. We have carried out radiography tests with X-rays induced from an ultra short pulse intense laser.

WEPWO036

Conceptual Design of a Superfluid Superconducting Third Harmonic RF System for the SSRF Storage Ring

cavity, superconducting-cavity, controls, synchrotron

2381

H.T. Hou, J.F. Liu, Z.T. Zhao
SINAP, Shanghai, People's Republic of China
J.F. Liu
Shanghai KEY Laboratory of Cryogenics & Superconducting RF Technology, Shanghai, People's Republic of China

Harmonic cavity can improve the beam quality through bunch size lengthening which includes providing Landau damping, suppressing coupled bunch instability and microwave instability, enhancing the beam current per bunch besides the beam lifetime improvement. A passive third harmonic superconducting cavity operating at super fluid liquid helium has been proposed for the SSRF storage ring with compromise on the required harmonic voltage, limited installation space and dissipated cryogenic power. This paper will mainly present the conceptual design of the harmonic rf system including the requirement of SSRF, a brief review on beam dynamics of harmonic rf system and the harmonic cavity choice.

WEPWO042

Dubna-Minsk SRF Technology Development Status Report

cavity, niobium, coupling, electron

2393

N.S. Azaryan, Ju. Boudagov, D.L. Demin, V.V. Glagolev, G. Shirkov, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
M.A. Baturitsky, N.M. Shumeiko
NC PHEP BSU, Minsk, Belarus
S.E. Demyanov, E.Yu. Kaniukov
Scientific-Practical Materials Research Centre of the National Academy of Sciences of Belarus, Minsk, Belarus
A. Ermakov, W. Singer, X. Singer
DESY, Hamburg, Germany
V.A. Karpovich, N.V. Liubetsky
BSU, Minsk, Belarus
S.V. Kolosov, A.A. Kurayev, A.O. Rak, A.K. Sinitsyn
Belarus State University of Informatics and Radioelectronics (BSUIR), Minsk, Belarus
S.I. Maximov, V.N. Rodionova
Belarussian State University, Scientific Research Institute of Nuclear Problems, Minsk, Belarus
A. Parshuto, V.S. Petrakovsky, I.L. Pobol, A.I. Pokrovsky, S.V. Yurevich, A.Yu. Zhuravsky
Physical-Technical Institute of the National Academy of Sciences of Belarus, Minsk, Belarus

In 2011 Dubna-Minsk collaboration started an activity on the development and manufacture the series of 1.3 GHz superconducting Nb cavities in the enterprises in Belarus. The current status of this work is presented in this report. Main EM characteristics of the cavity were calculated and the shop drawings for cavity fabrication were developed. Two test-benches were assembled for RF-tests of the cavities at room temperature and at liquid helium temperature. The measured SWR was about 1.01 due to special matching device developed for that. This measurement technique was applied to the single-cell cavity from FNAL at power level nearby 10 mW. Measured resonant frequency was about 1.27 GHz, while the measured Q-factor was 2.8·10⁴ at room temperature and more than 10⁸ at liquid helium temperature. To evaluate mechanical properties of sheet Nb and of model materials (Cu and Al), a number of tests were made. Series of half-cells were fabricated of Al to test the technique of hydraulic deep-drawing that will be used in production of Nb cavities. The modes for electron-beam welding of sheet Nb were explored and the first welding seams were tested. The method of chemical treatment of cavities was also elaborated.

Poster WEPWO042 [0.897 MB]

WEPWO076

Development of Ultra High Gradient and High Q0 Superconducting Radio Frequency Cavities

cavity, niobium, SRF, acceleration

2474

R.L. Geng, W.A. Clemens, J. Follkie, T. Harris, D. Machie, R. Martin, A.D. Palczewski, E. Perry, G. Slack, R.S. Williams
JLAB, Newport News, Virginia, USA
C. Adolphsen, Z. Li
SLAC, Menlo Park, California, USA
J.K. Hao, Y.M. Li, K.X. Liu
PKU, Beijing, People's Republic of China
P. Kushnick
JLab, Newport News, Virginia, USA

Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q0 superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q0 of 10¹⁰ at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q0 of 2·10¹⁰ at 2K.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

THOBB201

Pathway to a Post Processing Increase in Q0 of SRF Cavities

cavity, shielding, niobium, SRF

3129

O. Kugeler, J. Knobloch, J.M. Vogt
HZB, Berlin, Germany
S. Aull
CERN, Geneva, Switzerland

A significant improvement of Q0 to values larger than 3.2x10¹⁰ at 1.8K has been repeatedly achieved in an SRF cavity by thermal cycling, i.e. heating the cavity briefly above transition temperature and subsequent cooling. Conceivable explanations for this effect reach from effectivity deviations of the magnetic shielding to thermal currents to hydrogen diffusion. Experimental We have experimentally verified some of these explanations, leaving a direct impact of cooling dynamics on frozen flux as the most plausible one. The pathway to this finding is being presented and the application to SRF systems is elicited.

Slides THOBB201 [1.184 MB]

THPEA044

Radiation Tolerance of Cryogenic Beam Loss Monitor Detectors

proton, radiation, 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.

THPFI005

Simulations for Mechanical Design of Nozzle for Extrude of Windowless Solid Hydrogen Cryogenic Target

simulation, target, extraction

3297

H. Gassot, C. Commeaux
IPN, Orsay, France

The hydrogen (H2 and D2) target is the determining element of unstable nucleus spectroscopy. This target is proposed for heavy ions beam of several MeV/nucleon in SPIRAL and SPIRAL 2 projects. Without window, the carbone contamination of the hydrogen target could be avoided. Within the project of CHyMENE (Cible d’Hydrogène Mince pour l’Etude des Noyaux Exotiques), the development of hydrogen target is supported by ANR (Agence National de la Recherche) which federates differents French research institutes such as CNRS and CEA. The IPN Orsay is involved on the conception and simulations of a nozzle which can deliver a solid ribbon of 50 micron thickness; it is a very challenging program since the knowledge about hydrogen solid at 12 K is rare, especially in terms of experimental characterizations. The important work consists at first to propose models of simulations in order to study mechanical behaviours of solid hydrogen at cryogenic temperature under pressure and optimize the geometry parameters as well as rheology properties of nozzle. The mechanical non linear modelling including contact behaviours are presented. The first simulations results are summarized.

THPFI093

Device and Technique for In-situ Coating of the RHIC Cold Bore Vacuum Tubes with Thick OFHC

electron, vacuum, cathode, superconducting-magnet

3508

A. Hershcovitch, M. Blaskiewicz, J.M. Brennan, W. Fischer, C.J. Liaw, W. Meng, R.J. Todd
BNL, Upton, Long Island, New York, USA
A.X. Custer, M.Y. Erickson, N.Z. Jamshidi, H.J. Poole
PVI, Oxnard, USA
J.M. Jimenez, H. Neupert, M. Taborelli, C. Yin Vallgren
CERN, Geneva, Switzerland
N. Sochugov
Institute of High Current Electronics, Tomsk, Russia

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
To mitigate electron clouds & unacceptable ohmic heating problems in RHIC, we developed a robotic plasma deposition technique & device to in-situ coat the RHIC 316LN SS cold bore tubes based on mobile mole mounted magnetrons for OFHC deposition. Scrubbed Cu has low SEY and suppress electron cloud formation. Room temperature RF resistivity measurement of Cu coated SS RHIC tube samples indicate that 10 μm of Cu coating has conductivity close to copper tubing. A 50 cm long copper cathode magnetron, mounted on a carriage with spring loaded wheels, was successfully operated, traversed magnet interconnect bellows and adjusted for variations in vacuum tube diameter, while keeping the magnetron centered. To maximize cathode lifetime, Cu cathode thickness was maximized its gap to vacuum tube minimized; movable magnet package is used. Novel cabling and vacuum-atmosphere interface system is being developed. Deposition experiments show no indentation in or damage to coating after wheels roll over coated areas; i.e. train like assembly option is a viable for in-situ RHIC coating. Details of experimental setup & coating of full-scale magnet tube sandwiched between bellows will be presented.

THPME025

Design of Cryomodules for RAON

cryomodule, cavity, linac, vacuum

3558

Y. Kim, C. Choi, D. Jeon, H.J. Kim, M. Lee
IBS, Daejeon, Republic of Korea

The RAON linac utilizes four types of superconducting cavities such as QWR, HWR, SSR1, and SSR2 which are operating at 2 K in order to accelerate the various ion beams. The main role of the cryomodules is to maintain the cryogenic temperature for the superconducting cavity operation. Five types of cryomodules will be necessary since one QWR cavity, three and six HWR cavities, four SSR1 cavities, and eight SSR2 cavities will be installed in the dedicated cryomdoules. Total number of the cryomodule is 147, 48 for QWR, 60 for HWR, 22 for SSR1, 17 for SSR2. The cryomodules of RAON does not include focusing magnets but includes the cavities operating at 2 K. This paper describes the current status of the RAON cryomodule design. The issues included in the paper are the thermal load estimation, design of the components such as thermal shield and intercept of the cryomodules, and cryogenic flow circulation system according to the cryomodule operation.

THPME034

The LHC Cryogenic Operation Availability Results from the First Physics Run of Three Years

controls, instrumentation, monitoring, collider

3585

D. Delikaris, K. Brodzinski, S.D. Claudet, G. Ferlin, L.J. Tavian, U. Wagner
CERN, Geneva, Switzerland

The LHC (Large Hadron Collider) accelerator consists in eight cryogenically independent sectors, each 3.3 km long with a cold mass of 4500 ton cooled at 1.9 K. Each helium cryogenic plant combines an 18 kW at 4.5 K refrigerator and a 2.4 kW at 1.8 K refrigeration unit. Since early operation for physics in November 2009, the availability has been above 90% for more than 260 days per year, ending at 94.8% in 2012 and corresponding to an equivalent availability of more than 99% per independent sector. The operation and support methodology as well as the achieved performance results are presented. Emphasis is given on implementing operational return for short, medium and long term consolidations. Perspective for restart after the first long shutdown of the LHC works will be described.

THPME035

The Electronic System Design and Realization for First Set 500 MHz KEKB SRF Module High Power Test

SRF, controls, cavity, HOM

3588

F.-T. Chung, L.-H. Chang, M.H. Chang, L.J. Chen, M.-C. Lin, Y.-H. Lin, Z.L. Liu, C.H. Lo, M.H. Tsai, Ch. Wang, T.-T. Yang, M.-S. Yeh, T.-C. Yu
NSRRC, Hsinchu, Taiwan

This article reports the home-made electronics circuits for reading the various electronics signals which can be used for site acceptance of superconducting resonant cavity. The adjustment of parameters during 1st SRF high power acceptance can also be used for the update of the 2nd electronics. The modular electronics system will provide the advantages of fast repair, preparing spare parts easily, short install time and flexible adjustment. The hardware whole electronics system is mainly designed by CPLD, PLC and Display meters. The Military Standard connectors are used for signals connection. There are always junction boxes for signal transmission test and convenient signal jumping for ensuring the correct signal source. In safety action, there are Fast Interlock Sum (0-10us) and slow ready chain (50ms-150ms). The complete system realizes the real time monitor and protection of superconducting resonant cavity.

THPME039

The Control System for the Purification Station at NSRRC

controls, monitoring, vacuum, synchrotron

3597

T.F. Lin, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, C.K. Kuan, H.C. Li, C.P. Liu, H.H. Tsai
NSRRC, Hsinchu, Taiwan

A cryogenic adsorber was used liquid nitrogen to trap the impurities from gaseous helium in the helium cryogenic system. NSRRC parallel connected five cryogenic adsorbers for the cryogenic system in the year 2011; five additional cryogenic adsorbers will be installed in the year 2013. The original design of liquid nitrogen filling was motored and controlled manually to keep the efficiency of the purifying. The regeneration of the cryogenic adsorber must be performed manually as well by using heater and vacuum pump after saturated of the cryogenic adsorber. NSRRC develop one control system that is allowed the liquid nitrogen filling and regeneration process turns into automatically. This paper is aimed to present the construction of the control system. The installation and test results will be included in this paper as well.

THPME040

The Installation and Commissioning of the Helium Cryogenic System for theTPS Project

SRF, storage-ring, electron, controls

3600

H.H. Tsai, S.-H. Chang, W.-S. Chiou, F. Z. Hsiao, C.K. Kuan, H.C. Li, T.F. Lin, C.P. Liu
NSRRC, Hsinchu, Taiwan

The construction of an electron accelerator with energy 3 GeV is under way for high brilliance and flux X-ray photon source at NSRRC. There will be eventually four superconducting radio frequency (SRF) cavities installed to maintain the electron energy. The helium cryogenic system has been designed and fabricated to provide the required liquid helium for SRF cavities. The cryogenic system consists of the 700-W refrigerator, the 315-kW variant frequency compressor, the oil removal system, the recovery compressor system, the gas helium buffer tanks, and one 7000-L liquid helium Dewar. The overall system installation and commissioning will be presented and discussed in this paper.

THPWA035

Intervention Management from Operation to Shutdown

radiation, controls, feedback, site

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, radiation, 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.

THPWO011

Status of the SIS100 Heavy Ion Synchrotron Project at FAIR

dipole, quadrupole, ion, extraction

3782

P.J. Spiller, U. Blell, O. Boine-Frankenheim, L.H.J. Bozyk, E.S. Fischer, E. Floch, F. Hagenbuck, F. Hehenberger, M. Kauschke, O.K. Kester, A. Klaus, H. Klingbeil, H.G. König, P. Kowina, J.P. Meier, P. Moritz, C. Mühle, C. Omet, D. Ondreka, N. Pyka, H. Ramakers, P. Schnizer, J. Stadlmann, K. Sugita, D. Theuerkauf, B. Walasek-Höhne, St. Wilfert
GSI, Darmstadt, Germany

SIS100 is a unique superconducting heavy ion synchrotron, optimized for the acceleration of intense beams of intermediate charge state heavy ions. The operation with such beams has required new synchrotron design features and new technical concepts aiming for minimized ionization beam loss and vacuum dynamics. SIS100 is a superconducting synchrotron because of the required vacuum conditions and pumping power to achieve stable XHV conditions at high intensity operation. The project and procurement status will be presented.