IPAC2012 - List of Keywords (cryogenics)

Paper	Title	Other Keywords	Page
MOOBA02	Status and Future Perspectives of the HIE-ISOLDE Project at CERN	linac, cryomodule, solenoid, ion	34
	Y. Kadi, A.P. Bernardes, Y. Blumenfeld, S. Calatroni, R. Catherall, M.A. Fraser, B. Goddard, D. Parchet, E. Siesling, W. Venturini Delsolaro, D. Voulot, L.R. Williams CERN, Geneva, Switzerland
	The High Intensity and Energy (HIE)-ISOLDE project aims at several important upgrades of the present ISOLDE radioactive beam facility at CERN. The main focus lies in the energy upgrade of the post-accelerated radionuclide beams from 3 MeV/u up to 10 MeV/u through the addition of superconducting cavities. This will open the possibility of many new types of experiments including transfer reactions throughout the nuclear chart. The first stage of this upgrade involves the design, construction, installation and commissioning of two high-β cryomodules downstream of REX-ISOLDE, the existing post-accelerator. Each cryomodule houses five high-β sc cavities and one sc solenoid. Prototypes of the Nb-sputtered Quarter Wave Resonators (QWRs) cavities for the new superconducting linear accelerator have been manufactured and are undergoing RF cold tests. The project also includes a design study of improved production targets to accommodate the future increase of proton intensity delivered by the new LINAC4 proton driver. The project has been approved by CERN and its implementation started in January 2010. An overview of the project and the timeline will be presented.
	Slides MOOBA02 [7.044 MB]

MOOAC02	Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab	cryomodule, SRF, electron, gun	58
	J.R. Leibfritz, R. Andrews, C.M. Baffes, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln Fermilab, Batavia, USA P. Piot Northern Illinois University, DeKalb, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. The Advanced Superconducting Test Acccelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.
	Slides MOOAC02 [13.423 MB]

MOPPP075	The Research on Magnetic Properties of Magnet for SSRF Cryogenic Permanent Magnet Undulator	undulator, permanent-magnet, radiation, synchrotron	735
	Y.Z. He, L. Wang, Q.G. Zhou SINAP, Shanghai, People's Republic of China
	The temperature coefficient of Br and Hci of Nd2Fe14B and Pr2Fe14B permanent magnet are about -0.1 K-1 and -0.6 K-1 respectively, the higher Br and Hci can be obtained at low temperature. By this theory, a cryogenic permanent magnet undulator(CPMU) may be designed, the maximum magnetic field and the Hci of permanent magnet increased 10-50% and 300-500% respectively, compared with the conventional undulators, the higher brightness X-rays and the more resistance to radiation of undulators can be obtained. The Pr2Fe14B permanent magnet has better potential magnetic properties than the Nd2Fe14B permanent magnet at low temperature for having no spin reorientation phenomenon. The permanent magnets are key “heart” magnetic components for cryogenic permanent magnet undulator, since January 2012, the research plan on magnetic properties of domestic permanent magnet for SSRF cryogenic permanent magnet undulator at low temperature by the support of Shanghai and Nation Nature science funds be started, the paper introduced research status of the item.

MOPPP086	Praseodymium Iron-Boron Undulator With Textured Dysprosium Poles for Compact X-Ray FEL Applications	undulator, simulation, insertion, insertion-device	756
	R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh RadiaBeam, Santa Monica, USA F.H. O'Shea UCLA, Los Angeles, California, USA V. Solovyov BNL, Upton, Long Island, New York, USA
	Funding: DOE SBIR #97134S11-I Radiabeam Technologies is developing a novel ultra-high field short period undulator using two unconventional materials: praseodymium permanent magnets (PrFeB) and textured dysprosium (Tx Dy) ferromagnetic field concentrators. Both materials exhibit extraordinary magnetic properties at cryogenic temperatures, such as very large energy product and record high induction saturation, respectively. The proposed device combines PrFeB and Tx Dy in 3-D hybrid undulator geometry with sub-cm period and up to 3 Tesla pole tip field. Practical realization of these features will significantly surpass state-of-the-art and offer an ideal solution for the next generation of compact X-ray light sources. Initial simulations along with preliminary cryogenic measurements will be presented.

MOPPP089	Development of a PrFeB Cryogenic Undulator at NSLS-II	undulator, vacuum, synchrotron, permanent-magnet	762
	C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, H.C. Fernandes, D.A. Harder, P. He, G. Rakowsky, J. Rank, C. Rhein, T. Tanabe BNL, Upton, Long Island, New York, USA
	Recent cryogenic undulators use Praseodymium-Iron-Boron (PrFeB) magnets cooled down to 80K. The main drawn drawback of the PrFeB magnet grades developed so far are their relative low coercive field at ambient temperature, below 2 T which prevents PrFeB based cryogenic undulator from baking. Some precautions are required during the undulator assembling and shimming to ensure ultra high vacuum compatibility. However Hitachi Metal Industry (HMI) recently developed two different grades of PrFeB magnet with large coercive field but at the expense of the remanent field. The magnetization curves have been measured from 40 K up to 400 K to determine the field increase and to investigate the magnet withstanding to baking. An IVU prototype has also been baked. Magnetic measurements before and after baking are also presented.

MOPPR020	An Improved Cryogenic Current Comparator for FAIR	pick-up, shielding, niobium, ion	822
	R. Geithner, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany F. Kurian, H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	Online monitoring of low intensity (below 1 μA) charged particle beams without disturbing the beam and its environment is crucial for any accelerator facility. For the upcoming FAIR project a beam monitor based on the Cryogenic Current Comparator principle with an enhanced resolution was developed. The main focus of research was on the low temperature properties of the ferromagnetic core material of the superconducting pickup coil. The pickup coil transforms the magnetic field of the beam into a current that is detected by a high performance low temperature dc Superconducting QUantum Interference Device (LTS-DC-SQUID). The penetration of the pickup coil by interfering magnetic fields is highly attenuated by a meander shaped superconducting shielding. The Cryogenic Current Comparator is able to measure DC beam currents, e.g. as required for slow extraction from a synchrotron, as well as bunched beams. In this contribution we present first results of the improved Cryogenic Current Comparator working in a laboratory environment.

TUOAB02	Investigation of the Use of Silicon, Diamond and Liquid Helium Detectors for Beam Loss Measurements at 2 Kelvin	radiation, proton, electron, interaction-region	1080
	C. Kurfuerst, B. Dehning, W.T. Eisel, M. Sapinski CERN, Geneva, Switzerland V. Eremin IOFFE, St. Petersburg, Russia C. Fabjan HEPHY, Wien, Austria
	At the triplet magnets, close to the interaction regions of the LHC, the current Beam Loss Monitoring (BLM) system is very sensitive to the debris from the collisions. For future beams with higher energy and higher luminosity this will lead to a situation in which the BLM system can no longer distinguish between these interaction products and quench-provoking beam losses from the primary proton beams. The solution investigated is to locate the detectors as close as possible to the superconducting coil, i.e. the element to be protected. This means putting detectors inside the cold mass of the superconducting magnets at 1.9 K. As possible candidates for such loss monitors, diamond, silicon and a liquid helium chamber have been tested in a proton beam at liquid helium temperatures. The initial promising results from these tests will be presented and discussed in this contribution.
	Slides TUOAB02 [3.412 MB]

TUPPD004	Costing Methodology and Status of the Neutrino Factory	target, linac, solenoid, factory	1410
	A. Kurup Imperial College of Science and Technology, Department of Physics, London, United Kingdom N. Bliss, N.A. Collomb, A.F. Grant STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
	The International Design Study for the Neutrino Factory will produce a reference design report in 2013 that will contain a detailed performance analysis of the Neutrino Factory and a cost estimate. In order to determine the cost a number of engineering features need to be included in the accelerator physics design, which can require the physics design to be re-optimized. The cost estimate is determined in such a way as to make efficient use of the engineering resources available and to simplify the process of modifying the physics design to include engineering features. This paper will present details of the methodology used to determine the cost estimate and the current status of each subsystem.

TUPPP007	Modifications to the Machine Optics of BESSY II Necessitated by the EMIL Project	undulator, optics, dipole, storage-ring	1614
	P.O. Schmid, J. Bahrdt, T. Birke, R. Follath, P. Kuske, D. Simmering, G. Wüstefeld HZB, Berlin, Germany
	The Helmholtz Zentrum Berlin and the Max Planck Society are going to build a new dedicated X-ray beam line at the synchrotron source light source BESSY II which will be used for analyzing materials for renewable energy generation. The new large scale project has been dubbed EMIL. In this document we present the modifications to the machine optics and to what extent these changes affect the performance of BESSY II.

TUPPR004	ILC Conventional Facility in Asian Sites	site, linac, radiation, HLRF	1816
	A. Enomoto, M. Miyahara KEK, Ibaraki, Japan
	The international linear collider (ILC) is on a stage of preparing technical design report (TDR). Through value engineering to reduce civil construction costs, the tunnel configuration was changed from double- tunnel scheme to single. The double-tunnel schme accomodates superconducting accelerator modules and their power supplies indipendently. This is a very natural scheme for setting an accelerator and its power supply nearby and for preventing radiation damage of the power supply. However, the single-tunnel scheme was proposed to reduce cost, and to avoid such radiation problem three kinds of high-level (HLRF) RF systems are proposed. We report the comparison of ILC main linac costs and construction schedules between eight cases for combinations of diferent tunnel excavation methods and HLRF systems; then, we report the potential facility design for the Asian sites.

WEPPC006	CW and LP Operation Test of XFEL-Like Cryomodule	HOM, cryomodule, cavity, feedback	2215
	J.K. Sekutowicz, V. Ayvazyan, M. Ebert, J. Eschke, A. Gössel, D. Kostin, I.M. Kudla, W. Merz, F. Mittag, R. Onken DESY, Hamburg, Germany W. Cichalewski, W. Jałmużna, K.P. Przygoda TUL-DMCS, Łódź, Poland K. Czuba, L. Zembala Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland J. Szewiński The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland
	A continuous improvement in the performance of superconducting TESLA cavities will make possible, from the cryogenic point of view, operation of the XFEL linac in continuous wave (cw) mode at gradients up to 7.5 MV/m and in long pulse (lp) mode up to nominal gradient of 23.4 MV/m. Each of these new operation modes will offer an additional flexibility in time structure of the photon beam, and therefore will allow for more experiments and in some cases less demanding and less expensive equipment. In this contribution we discuss results of the first RF test of these new types of operation with a XFEL-like cryomodule.

WEPPC024	Preliminary Test of Superconducting RF Cavities for PLS-II	SRF, cavity, cryomodule, vacuum	2257
	Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: This project is supported by the Korea Ministry of Science and Technology. The main part of the Installation for the PLS-II upgrade was finished in June and is on the way to user operation through elaborate commissioning. Up to now, the achievement is 150 mA beam current at 3 GeV with multi-bunch mode with 5 normal conducting cavities which served in the PLS before. After installation of 2 SRF cavities in the summer of 2012, the PLS-II will have 300 mA beam current with 20 IDs by 2 superconducting RF cavities until July, 2014. Finally, one more superconducting cavity will be added in August, 2014, and beam current will rise to 400 mA. The two SRF cavities are under test and conditioning. The two main subsystems, SRF cavities and ceramic windows were tested independently to confirm their performance. Each cavity recorded its accelerating voltage as 3.27 MV and 3.24 MV at 4.2K, respectively. Two RF windows also passed their specification, 300 kW CW traveling wave and 150 kW CW standing wave. The preliminary tests of SRF cryomodules are reported in the presentation.

WEPPC030	Second Sound Measurement Using SMD Resistors to Simulate Quench Locations on the 704 MHz Single-cell Cavity at CERN	cavity, simulation, linac, quadrupole	2269
	K.C. Liao, O. Brunner, E. Ciapala, T. Junginger, W. Weingarten CERN, Geneva, Switzerland
	Oscillating superleak transducers (OSTs) containing a flexible porous membrane are widely used to detect the so-called second sound temperature wave when a quench event occurs in a superconducting RF cavity. In principle, from the measured speed of this wave and the travel time between the quench event and several OSTs, the location of the quench sites can be derived by triangulation. Second sound behavior has been simulated though different surface mount (SMD) resistors setups on a Superconducting Proton Linac (SPL) test cavity, to help understand the underlying physics and improve quench localisation. Experiments are described that have been conducted to search for explanation of heat transfer mechanism during cavity quench that causes contradictory triangulation results.
	Poster WEPPC030 [1.473 MB]

WEPPC031	Completed Assembly of the Daresbury International ERL Cryomodule and its Implementation on ALICE	cryomodule, cavity, HOM, controls	2272
	P.A. McIntosh, M.A. Cordwell, P.A. Corlett, P. Davies, E. Frangleton, P. Goudket, K.J. Middleman, S.M. Pattalwar, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S.A. Belomestnykh BNL, Upton, Long Island, New York, USA A. Büchner, F.G. Gabriel, P. Michel HZDR, Dresden, Germany J.N. Corlett, D. Li, S.M. Lidia LBNL, Berkeley, California, USA G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin, V. Veshcherevich CLASSE, Ithaca, New York, USA T.J. Jones, J. Strachan STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada D. Proch, J.K. Sekutowicz DESY, Hamburg, Germany T.I. Smith Stanford University, Stanford, California, USA
	The completion of an optimised SRF cryomodule for application on ERL accelerators has now culminated with the successful assembly of an integrated cryomodule, following an intensive 5 years of development evolution. The cryomodule, which incorporates 2 x 7-cell 1.3 GHz accelerating structures, 3 separate layers of magnetic shielding, fully adjustable & high power input couplers and fast piezo tuners, has been installed on the ALICE ERL facility at Daresbury Laboratory. It is intended that this will permit operational optimisation for maximised efficiency demonstration, through increased Qext adjustment whilst retaining both effective energy recovery and IR-FEL lasing. The collaborative design processes employed in completing this new cryomodule development are explained, along with the assembly and implementation procedures used to facilitate its successful installation on the ALICE ERL facility.

WEPPC041	Tests of SRF Deflecting Cavities at 2K	cavity, SRF, vacuum, photon	2300
	J.D. Fuerst, D. Horan, J. Kaluzny, A. Nassiri, T.L. Smith, G. Wu ANL, Argonne, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is developing 2.8-GHz deflecting-mode superconducting rf cavities in collaboration with Jefferson Lab as part of a major facility upgrade. On-site testing of these cavities requires a new cryostat capable of operation at 2.0 K or less. The APS has leveraged facilities and expertise within ANL’s Physics Division to upgrade an existing test stand for continuous operation at temperatures as low as 1.7 K. A new cryogenic feedbox was fabricated and mated to an existing liquid helium “bucket” dewar with 0.6-m inside diameter and 1-m working depth. The configuration allows continuous sub-λ operation using warm vacuum pumping and helium make-up from the Physics Division’s existing cryoplant at heat loads up to 50 W dynamic, plus 15 W measured static load at 2.0 K. A 2.8-GHz TWT-based rf station has been installed and commissioned, providing up to 275 W of rf power. We describe the cryogenic and rf performance of the system and provide examples of cavity test results.

WEPPC075	Testing of the Main-Linac Prototype Cavity in a Horizontal Test Cryomodule for the Cornell ERL	cavity, linac, cryomodule, HOM	2387
	N.R.A. Valles, F. Furuta, G.M. Ge, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, M. Tigner, V. Veshcherevich CLASSE, Ithaca, New York, USA
	Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac (ERL). The cavity construction met all necessary fabrication constraints. After a bulk BCP, 650C outgassing, final BCP, and 120C bake the cavity was vertically tested. The cavity met quality factor and gradient specifications (2·10¹⁰ at 16.2 MV/m) in the vertical test. Progressing with the ERL linac development, the cavity was installed in a horizontal test cryomodule and the quality factor versus accelerating gradient was again measured. This baseline measurement is the first test in a sequence of tests of the main linac cavity in the test cryomodule. Subsequent tests will be with increased complexity of the beam line, e.g. with HOM beamline loads installed, to study potential sources of reducing the cavity’s quality factor.

WEPPC095	Evaluation of Silicon Diodes as In-situ Cryogenic Field Emission Detectors for SRF Cavity Development	cavity, ion, radiation, SRF	2438
	A.D. Palczewski, R.L. Geng JLAB, Newport News, Virginia, USA
	Funding: This work is authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We performed in-situ cryogenic testing of five silicon diodes as possible candidates for field emission monitor of SRF cavities in vertical testing dewars and in cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S5821-02 (used at KEK)* and S1223-02; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and their directionality in such environments. We will also present calibration curves between the diodes and JLab’s standard radiation detector placed above the dewar top plate and within radiation shielding. * H. Sakai et al., Proc of IPAC10, WEPEC028 p. 2950 (2010).

WEPPD002	The Purifier System for Helium Cryogenic Plant in NSRRC	controls, cavity, SRF, synchrotron	2498
	H.C. Li, S.-H. Chang, C.M. Cheng, W.-S. Chiou, F. Z. Hsiao, T.F. Lin, C.P. Liu, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A cryogenic adsorber is a purifier cooled with liquid nitrogen that is used to trap impurities from gaseous helium in the helium cryogenic system. The output purity can be decreased to less than 5 ppm and the dew point to -62 °C. The maximum rate of flow of each adsorber is 95 Nm3/h. We installed five cryogenic adsorbers in the cryogenic system and completed its testing in 2011; five additional cryogenic adsorbers will be installed in 2012. The configuration, installation, test results and operation of an cryogenic adsorber system are reported herein. "cryogenic adsorber","purifier"

WEPPD003	Development of a Condenser for the Helium Phase Separator at NSRRC	simulation, vacuum, synchrotron, synchrotron-radiation	2501
	C.P. Liu, C.M. Cheng, F. Z. Hsiao, T.Y. Huang, H.H. Tsai NSRRC, Hsinchu, Taiwan
	A helium phase separator with a condenser is under fabrication and assembly at National Synchrotron Radiation Research Center (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryo-cooler of Gifford-McMahon type. This paper presents the design and fabrication of the condenser, a key component of the helium phase separator. A preliminary steady-state simulation of the efficiency of the helium condenser is also presented. "Condenser","Rate of condensation"

WEPPD005	SSR1 Cryomodule Design PXIE	cryomodule, vacuum, cavity, solenoid	2504
	T.H. Nicol, S. Cheban, M. Chen, S. Kazakov, F. McConologue, Y. Orlov, D. Passarelli, V. Poloubotko, O. Pronitchev, L. Ristori, I. Terechkine Fermilab, Batavia, USA
	Funding: U.S. Department of Energy Fermilab is planning to design and build a Project X Injector Experiment (PXIE), a cw linac, as a means of validating the Project X concept, reducing technical risks, and obtaining experience in the design and operation of a superconducting proton linac. The overall facility will include an ion source, low and medium-energy beam transport sections, a radio frequency quadrupole, and two cryomodules containing superconducting cavities. One will contain nine half-wave resonators operating at 162.5 MHz and six superconducting solenoids. The second will contain eight single spoke resonators (SSR1) operating at 325 MHz and four superconducting solenoids. This paper describes the design of the cryomodule being developed to house the 325 MHz single spoke resonators. Each of the main cryomodule systems will be described; cryogenic systems and instrumentation, cavity and solenoid positioning and alignment, conduction-cooled current leads, RF input couplers, magnetic shielding, cold-to-warm beam tube transitions, interfaces to interconnecting equipment and adjacent modules, as well as the overall assembly procedure.

WEPPD006	Design of the FRIB Cryomodule	cryomodule, alignment, solenoid, vacuum	2507
	M.J. Johnson, M. Barrios, J. Binkowski, S. Bricker, F. Casagrande, A.D. Fox, B.R. Lang, M. Leitner, S.J. Miller, T. Nellis, J.P. Ozelis, X. Rao, J. Weisend, Y. Xu FRIB, East Lansing, Michigan, USA D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman JLAB, Newport News, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 An advanced, modular bottom-supported cryomodule design is described which is highly optimized for mass-production and efficient precision-assembly. The FRIB driver linac uses 4 types of superconducting resonators and 2 solenoid lengths which in turn require 7 individual cryomodule configurations. To meet alignment tolerances a precision-machined bolted cryomodule rail system is described. A novel, kinematic mounting system of the cold mass is introduced which allows for thermal contractions while preserving alignment. A first prototype will incorporate a wire position monitor for alignment verification. The cold alignment structure is supported by composite posts which also function as thermal isolators. The cryogenic system provides separate 2 K and 4.5 K liquid helium lines to cavities and solenoids. Details of the JT valves, heat exchanger, cool-down circuit and junction to cryogenic line will be provided. Transient cool-down was simulated for stresses and buckling failure. A 1100-O Aluminum shield is used as a thermal radiation shield. The paper also describes cryomodule interfaces with the linac tunnel, the RF input cables, and the cryogenic distribution system. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

WEPPD007	Integrated Thermal Analysis of the FRIB Cryomodule Design	cryomodule, vacuum, simulation, radiation	2510
	Y. Xu, M. Barrios, F. Casagrande, M.J. Johnson, M. Leitner FRIB, East Lansing, Michigan, USA D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman JLAB, Newport News, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Thermal analysis of the FRIB cryomodule design is performed to determine the heat load to the cryogenic plant, to minimize the cryogenic plant load, to simulate thermal shield cool down as well as to determine the pressure relief sizes for failure conditions. Static and dynamic heat loads of the cryomodules are calculated and the optimal shield temperature is determined to minimize the cryogenic plant load. Integrated structural and thermal simulations of the 1100-O aluminium thermal shield are performed to determine the desired cool down rate to control the temperature profile on the thermal shield and to minimize thermal expansion displacements during the cool down. Pressure relief sizing calculations for the SRF helium containers, solenoids, helium distribution piping, and vacuum vessels are also described. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

WEPPD008	Recondenser Performance: Impact on the Superconducting Undulator Magnet at Argonne National Laboratory	undulator, ion, background, factory	2513
	J.M. Pfotenhauer, D.M. Schick UW-Madison/EP, Madison, Wisconsin, USA
	Funding: This work is supported by Argonne National Laboratory, subcontract number 9F-31982. The current sharing temperature of 6.5 K for the superconducting undulator magnet being developed at Argonne National Laboratory drives the thermal design of the magnet’s cooling system. In order to remain below the current sharing temperature, a thermo-siphon cooling loop is being developed to sweep the anticipated heat load away from the magnet windings and deposit it in the associated liquid helium reservoir located above the magnet. Performance of the magnet’s cooling system is crucially dependent on the ability of the re-condenser to maintain the reservoir’s saturation temperature near 4 K, despite thermal stratification and slowly varying thermal profiles within the vapor region above the liquid in the reservoir. Here we report the results of an experimental investigation of the impact of various geometric configurations for the re-condenser and the thermal resistance associated with the film layer at the re-condensing surface, on the time-varying saturation temperature within the helium reservoir. The resulting temporal thermal variations in the superconducting winding are highlighted as well as the impact they have on the magnet’s stability.

WEPPD029	The Mechanical Design of a Collimator and Cryogenic Bypass for Installation in the Dispersion Suppressors of the LHC	vacuum, superconducting-magnet, shielding, collimation	2567
	D. Ramos, L. Alberty Vieira, A. Bertarelli, A. Cherif, N. Chritin, R. Claret, L. Gentini, D. Lombard, P. Minginette, P. Moyret, M. Redondas Monteserin, T. Renaglia, M.A. Timmins CERN, Geneva, Switzerland
	A project to install collimators in the dispersion suppressor regions of the LHC was launched early 2010, aiming to reduce the power deposition in superconducting magnets by a factor of 10. To be placed in the continuous arc cryostat, the design of such collimators had to comply with challenging integration, functional and time constraints. A pre-study for a cold collimator solution was launched in parallel with an alternative design consisting of a room temperature collimator and a cryogenic bypass. The second was eventually preferred, as it was based on proven LHC technologies for cryogenic, vacuum, electrical and collimator material solutions, despite the increased difficulty on the mechanical integration and assembly. This paper presents the mechanical design of a cryogenic bypass for the LHC continuous cryostat and respective collimator unit, both made to comply with the functionality of existing LHC systems. The approach taken to achieve a reliable design within schedule will be explained alongside the measures adopted to validate new solutions, in particular, when dealing with welding distortions, systems routing, thermal loads and precision mechanics.

WEPPD043	The Studies of Power System Harmonics at TLS	coupling, power-supply, dipole, controls	2609
	T.-S. Ueng, J.-C. Chang, Y.F. Chiu, K.C. Kuo, Y.-C. Lin NSRRC, Hsinchu, Taiwan
	The power system harmonic distortion in the utility system of NSRRC is investigated for improving the power system performance. The monitored power quality data at the point of common coupling is examined and compared with industrial standards. In addition, the harmonic characteristics of electric power for the accelerator magnets and adjustable speed drives which contribute the most harmonics are analyzed. Furthermore, the approach to mitigate the harmonic effects for improving the power quality is studied.

WEPPD058	The Project-X 3 GeV Beam Distribution System	cavity, kaon, linac, ion	2651
	D.E. Johnson, M.H. Awida, M.S. Champion, I.V. Gonin, A.L. Klebaner, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	In the Project X facility, a 3 GeV H⁻ CW beam is delivered to three users simultaneously. This will be accomplished by selectively filling appropriate RF buckets at the front end of the linac and then utilizing a RF splitter to transversely separate bunches to three different target halls. A compact TE113 squashed-wall superconducting RF cavity has been proposed to produce the initial vertical deflection. The transport line optics, cavity design parameters, and cryogenic system requirements will be presented.

WEPPR018	Beam Experiments towards High-intensity Beams in RHIC	proton, injection, vacuum, radiation	2979
	C. Montag, L. A. Ahrens, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, T. Hayes, H. Huang, K. Mernick, G. Robert-Demolaize, K.S. Smith, R. Than, P. Thieberger, K. Yip, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Proton bunch intensities in RHIC will be increased from 210¹¹ to 310¹¹ protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results will be presented.

THEPPB004	Development of a Cryocatcher-System for SIS100	ion, vacuum, heavy-ion, simulation	3237
	L.H.J. Bozyk, H. Kollmus, P.J. Spiller GSI, Darmstadt, Germany
	Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI. The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THPPC039	Study of RF Breakdown in Normal Conducting Cryogenic Structure	impedance, klystron, lattice, accelerating-gradient	3368
	V.A. Dolgashev, J.R. Lewandowski, D.W. Martin, S.G. Tantawi, S.P. Weathersby, A.D. Yeremian SLAC, Menlo Park, California, USA
	Funding: *Work supported by DoE, Contract No. DE-AC02-76SF00515. RF Breakdown experiments on short accelerating structures at SLAC have shown that properties of rf breakdown probability are reproducible for structures of the same geometry. At a given rf power and pulse shape, the rf breakdown triggers continuously and independently at a constant average rate. Hypotheses describing the properties of the rf breakdown probabilities involve defects of metal crystal lattices that move under forces caused by rf electric and magnetic fields. The dynamics of the crystal defects depend on the temperature of the structure. To study the dependence we designed and built an experimental setup that includes a cryogenically cooled single-cell, standing-wave accelerating structure. This cavity will be high power tested at the SLAC Accelerator Structure Test Area (ASTA).

THPPD021	SC Magnet Development for SIS100 at FAIR	quadrupole, dipole, sextupole, multipole	3545
	E.S. Fischer, A. Mierau, P. Schnizer GSI, Darmstadt, Germany
	Superconducting magnets have been constructed and tested for the SIS100 (Heavy Ion Synchrotron with a beam rigidity of 100 Tm) of the FAIR project. The requested high quality of the magnetic field as well as the fast periodic ramp of the SIS100 (2T, 1Hz) requires that any source of AC losses is tightly reduced by carefully optimising the 3D geometry of the yoke, choosing the appropriate iron material and minimising the eddy current loops. In addition optimal wire, cable and coil designs have been developed. The residual heat production will be reliable removed by an efficient cooling scheme. The beam pipe vacuum chamber must operate stably as a cryo-pump with surface temperatures below 20K. The electromagnetic, thermal and mechanical aspects were optimised and finally investigated based on physical analysis, supported by FEM calculations and dedicated tests. The results obtained on the main magnets were used for dedicated development of the corrector magnets and their effective integration in the complete cryo-magnet complex of the accelerator. We describe the features of the final magnets next to their optimised fields and present the construction status of the SIS100 magnets.

THPPD027	Consolidation of the 13 kA Splices in the Electrical Feedboxes of the LHC	dipole, quadrupole, controls, superconducting-magnet	3560
	A. Perin, S. Atieh, O. Pirotte, R. Principe, D. Ramos, F. Savary, C.E. Scheuerlein, J.Ph. G. L. Tock, A.P. Verweij CERN, Geneva, Switzerland
	In 2008 a defective connection in one of the 13 kA dipole circuits of the LHC caused an electric breakdown that resulted in extensive damage in a sector of the accelerator. The investigation performed after the accident showed the necessity to consolidate the electrical splices of the 13 kA dipole and quadrupole circuits in order to operate the LHC at its nominal energy of 7 TeV. These circuits are powered through electrical feedboxes located at each end of the 8 sectors of LHC. In the feedboxes the current is routed from room temperature to the superconducting magnets along current leads and superconducting busbars and flows through at least two internal splices. These splices are based on the same technologies as the magnet to magnet ones but they are significantly different in terms of environment and configuration. As for the magnet to magnet splices, a consolidation will be necessary to operate them at nominal current. This paper presents an analysis of the properties of these splices and the technologies that will be used to consolidate them. The quality control provisions and the workflow to perform this operation during the first long shutdown of LHC are also presented.

THPPD028	Studies on the LHC Superconducting Circuits and Routine Qualification of Their Functionalities	dipole, collider, hadron, target	3563
	M. Pojer, G. D'Angelo, R. Mompo, R. Schmidt, M. Solfaroli Camillocci CERN, Geneva, Switzerland
	The Large Hadron Collider (LHC) is systematically undergoing periods of maintenance stop (either 4-5 days stops or longer Christmas breaks), after which some of the superconducting circuits (or the totality of them) have to be re-commissioned to check the correct functionality of all powering and protection systems. Detailed procedures have been developed during the past few years and they have been optimized to increase powering tests efficiency, thus reducing beam downtime. The approach to the routine qualification of the LHC powering systems is described in this paper. During 2011 technical stops, some particular studies on the superconducting circuits were performed, to assess the quality of the superconducting splices of individually powered magnets and to study the quench propagation in the main magnet bus-bars. The methodology of these tests and some results are also presented.

THPPD029	Machine Availability at the Large Hadron Collider	luminosity, controls, collider, hadron	3566
	M. Pojer, R. Schmidt, M. Solfaroli Camillocci, S. Wagner CERN, Geneva, Switzerland
	One of the most important parameters for a particle accelerator is its uptime, the period of time when it is functioning and available for use. In its second year of operation, the Large Hadron Collider (LHC) has experienced very high machine availability, which is one of the ingredients of its brilliant performance. Some of the strategies followed to increase MTBF are described in the paper. The approach of periodic maintenance stops, often questioned, is also discussed. Some considerations on the ideal length of a physics fill are also drawn.

THPPD033	Using Permanent Magnets to Boost the Dipole Field for the High-energy LHC	permanent-magnet, dipole, background, radiation	3578
	F. Zimmermann CERN, Geneva, Switzerland Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579. The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb-Ti, Nb3Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability.

Paper

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Other Keywords

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MOOBA02

Status and Future Perspectives of the HIE-ISOLDE Project at CERN

linac, cryomodule, solenoid, ion

34

Y. Kadi, A.P. Bernardes, Y. Blumenfeld, S. Calatroni, R. Catherall, M.A. Fraser, B. Goddard, D. Parchet, E. Siesling, W. Venturini Delsolaro, D. Voulot, L.R. Williams
CERN, Geneva, Switzerland

The High Intensity and Energy (HIE)-ISOLDE project aims at several important upgrades of the present ISOLDE radioactive beam facility at CERN. The main focus lies in the energy upgrade of the post-accelerated radionuclide beams from 3 MeV/u up to 10 MeV/u through the addition of superconducting cavities. This will open the possibility of many new types of experiments including transfer reactions throughout the nuclear chart. The first stage of this upgrade involves the design, construction, installation and commissioning of two high-β cryomodules downstream of REX-ISOLDE, the existing post-accelerator. Each cryomodule houses five high-β sc cavities and one sc solenoid. Prototypes of the Nb-sputtered Quarter Wave Resonators (QWRs) cavities for the new superconducting linear accelerator have been manufactured and are undergoing RF cold tests. The project also includes a design study of improved production targets to accommodate the future increase of proton intensity delivered by the new LINAC4 proton driver. The project has been approved by CERN and its implementation started in January 2010. An overview of the project and the timeline will be presented.

Slides MOOBA02 [7.044 MB]

MOOAC02

Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

cryomodule, SRF, electron, gun

58

J.R. Leibfritz, R. Andrews, C.M. Baffes, K. Carlson, B. Chase, M.D. Church, E.R. Harms, A.L. Klebaner, M.J. Kucera, A. Martinez, S. Nagaitsev, L.E. Nobrega, J. Reid, M. Wendt, S.J. Wesseln
Fermilab, Batavia, USA
P. Piot
Northern Illinois University, DeKalb, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
The Advanced Superconducting Test Acccelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

Slides MOOAC02 [13.423 MB]

MOPPP075

The Research on Magnetic Properties of Magnet for SSRF Cryogenic Permanent Magnet Undulator

undulator, permanent-magnet, radiation, synchrotron

735

Y.Z. He, L. Wang, Q.G. Zhou
SINAP, Shanghai, People's Republic of China

The temperature coefficient of Br and Hci of Nd2Fe14B and Pr2Fe14B permanent magnet are about -0.1 K-1 and -0.6 K-1 respectively, the higher Br and Hci can be obtained at low temperature. By this theory, a cryogenic permanent magnet undulator(CPMU) may be designed, the maximum magnetic field and the Hci of permanent magnet increased 10-50% and 300-500% respectively, compared with the conventional undulators, the higher brightness X-rays and the more resistance to radiation of undulators can be obtained. The Pr2Fe14B permanent magnet has better potential magnetic properties than the Nd2Fe14B permanent magnet at low temperature for having no spin reorientation phenomenon. The permanent magnets are key “heart” magnetic components for cryogenic permanent magnet undulator, since January 2012, the research plan on magnetic properties of domestic permanent magnet for SSRF cryogenic permanent magnet undulator at low temperature by the support of Shanghai and Nation Nature science funds be started, the paper introduced research status of the item.

MOPPP086

Praseodymium Iron-Boron Undulator With Textured Dysprosium Poles for Compact X-Ray FEL Applications

undulator, simulation, insertion, insertion-device

756

R.B. Agustsson, Y.C. Chen, T.J. Grandsaert, A.Y. Murokh
RadiaBeam, Santa Monica, USA
F.H. O'Shea
UCLA, Los Angeles, California, USA
V. Solovyov
BNL, Upton, Long Island, New York, USA

Funding: DOE SBIR #97134S11-I
Radiabeam Technologies is developing a novel ultra-high field short period undulator using two unconventional materials: praseodymium permanent magnets (PrFeB) and textured dysprosium (Tx Dy) ferromagnetic field concentrators. Both materials exhibit extraordinary magnetic properties at cryogenic temperatures, such as very large energy product and record high induction saturation, respectively. The proposed device combines PrFeB and Tx Dy in 3-D hybrid undulator geometry with sub-cm period and up to 3 Tesla pole tip field. Practical realization of these features will significantly surpass state-of-the-art and offer an ideal solution for the next generation of compact X-ray light sources. Initial simulations along with preliminary cryogenic measurements will be presented.

MOPPP089

Development of a PrFeB Cryogenic Undulator at NSLS-II

undulator, vacuum, synchrotron, permanent-magnet

762

C.A. Kitegi, P. Cappadoro, O.V. Chubar, T.M. Corwin, H.C. Fernandes, D.A. Harder, P. He, G. Rakowsky, J. Rank, C. Rhein, T. Tanabe
BNL, Upton, Long Island, New York, USA

Recent cryogenic undulators use Praseodymium-Iron-Boron (PrFeB) magnets cooled down to 80K. The main drawn drawback of the PrFeB magnet grades developed so far are their relative low coercive field at ambient temperature, below 2 T which prevents PrFeB based cryogenic undulator from baking. Some precautions are required during the undulator assembling and shimming to ensure ultra high vacuum compatibility. However Hitachi Metal Industry (HMI) recently developed two different grades of PrFeB magnet with large coercive field but at the expense of the remanent field. The magnetization curves have been measured from 40 K up to 400 K to determine the field increase and to investigate the magnet withstanding to baking. An IVU prototype has also been baked. Magnetic measurements before and after baking are also presented.

MOPPR020

An Improved Cryogenic Current Comparator for FAIR

pick-up, shielding, niobium, ion

822

R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
F. Kurian, H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

Online monitoring of low intensity (below 1 μA) charged particle beams without disturbing the beam and its environment is crucial for any accelerator facility. For the upcoming FAIR project a beam monitor based on the Cryogenic Current Comparator principle with an enhanced resolution was developed. The main focus of research was on the low temperature properties of the ferromagnetic core material of the superconducting pickup coil. The pickup coil transforms the magnetic field of the beam into a current that is detected by a high performance low temperature dc Superconducting QUantum Interference Device (LTS-DC-SQUID). The penetration of the pickup coil by interfering magnetic fields is highly attenuated by a meander shaped superconducting shielding. The Cryogenic Current Comparator is able to measure DC beam currents, e.g. as required for slow extraction from a synchrotron, as well as bunched beams. In this contribution we present first results of the improved Cryogenic Current Comparator working in a laboratory environment.

TUOAB02

Investigation of the Use of Silicon, Diamond and Liquid Helium Detectors for Beam Loss Measurements at 2 Kelvin

radiation, proton, electron, interaction-region

1080

C. Kurfuerst, B. Dehning, W.T. Eisel, M. Sapinski
CERN, Geneva, Switzerland
V. Eremin
IOFFE, St. Petersburg, Russia
C. Fabjan
HEPHY, Wien, Austria

At the triplet magnets, close to the interaction regions of the LHC, the current Beam Loss Monitoring (BLM) system is very sensitive to the debris from the collisions. For future beams with higher energy and higher luminosity this will lead to a situation in which the BLM system can no longer distinguish between these interaction products and quench-provoking beam losses from the primary proton beams. The solution investigated is to locate the detectors as close as possible to the superconducting coil, i.e. the element to be protected. This means putting detectors inside the cold mass of the superconducting magnets at 1.9 K. As possible candidates for such loss monitors, diamond, silicon and a liquid helium chamber have been tested in a proton beam at liquid helium temperatures. The initial promising results from these tests will be presented and discussed in this contribution.

Slides TUOAB02 [3.412 MB]

TUPPD004

Costing Methodology and Status of the Neutrino Factory

target, linac, solenoid, factory

1410

A. Kurup
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
N. Bliss, N.A. Collomb, A.F. Grant
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

The International Design Study for the Neutrino Factory will produce a reference design report in 2013 that will contain a detailed performance analysis of the Neutrino Factory and a cost estimate. In order to determine the cost a number of engineering features need to be included in the accelerator physics design, which can require the physics design to be re-optimized. The cost estimate is determined in such a way as to make efficient use of the engineering resources available and to simplify the process of modifying the physics design to include engineering features. This paper will present details of the methodology used to determine the cost estimate and the current status of each subsystem.

TUPPP007

Modifications to the Machine Optics of BESSY II Necessitated by the EMIL Project

undulator, optics, dipole, storage-ring

1614

P.O. Schmid, J. Bahrdt, T. Birke, R. Follath, P. Kuske, D. Simmering, G. Wüstefeld
HZB, Berlin, Germany

The Helmholtz Zentrum Berlin and the Max Planck Society are going to build a new dedicated X-ray beam line at the synchrotron source light source BESSY II which will be used for analyzing materials for renewable energy generation. The new large scale project has been dubbed EMIL. In this document we present the modifications to the machine optics and to what extent these changes affect the performance of BESSY II.

TUPPR004

ILC Conventional Facility in Asian Sites

site, linac, radiation, HLRF

1816

A. Enomoto, M. Miyahara
KEK, Ibaraki, Japan

The international linear collider (ILC) is on a stage of preparing technical design report (TDR). Through value engineering to reduce civil construction costs, the tunnel configuration was changed from double- tunnel scheme to single. The double-tunnel schme accomodates superconducting accelerator modules and their power supplies indipendently. This is a very natural scheme for setting an accelerator and its power supply nearby and for preventing radiation damage of the power supply. However, the single-tunnel scheme was proposed to reduce cost, and to avoid such radiation problem three kinds of high-level (HLRF) RF systems are proposed. We report the comparison of ILC main linac costs and construction schedules between eight cases for combinations of diferent tunnel excavation methods and HLRF systems; then, we report the potential facility design for the Asian sites.

WEPPC006

CW and LP Operation Test of XFEL-Like Cryomodule

HOM, cryomodule, cavity, feedback

2215

J.K. Sekutowicz, V. Ayvazyan, M. Ebert, J. Eschke, A. Gössel, D. Kostin, I.M. Kudla, W. Merz, F. Mittag, R. Onken
DESY, Hamburg, Germany
W. Cichalewski, W. Jałmużna, K.P. Przygoda
TUL-DMCS, Łódź, Poland
K. Czuba, L. Zembala
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
J. Szewiński
The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland

A continuous improvement in the performance of superconducting TESLA cavities will make possible, from the cryogenic point of view, operation of the XFEL linac in continuous wave (cw) mode at gradients up to 7.5 MV/m and in long pulse (lp) mode up to nominal gradient of 23.4 MV/m. Each of these new operation modes will offer an additional flexibility in time structure of the photon beam, and therefore will allow for more experiments and in some cases less demanding and less expensive equipment. In this contribution we discuss results of the first RF test of these new types of operation with a XFEL-like cryomodule.

WEPPC024

Preliminary Test of Superconducting RF Cavities for PLS-II

SRF, cavity, cryomodule, vacuum

2257

Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This project is supported by the Korea Ministry of Science and Technology.
The main part of the Installation for the PLS-II upgrade was finished in June and is on the way to user operation through elaborate commissioning. Up to now, the achievement is 150 mA beam current at 3 GeV with multi-bunch mode with 5 normal conducting cavities which served in the PLS before. After installation of 2 SRF cavities in the summer of 2012, the PLS-II will have 300 mA beam current with 20 IDs by 2 superconducting RF cavities until July, 2014. Finally, one more superconducting cavity will be added in August, 2014, and beam current will rise to 400 mA. The two SRF cavities are under test and conditioning. The two main subsystems, SRF cavities and ceramic windows were tested independently to confirm their performance. Each cavity recorded its accelerating voltage as 3.27 MV and 3.24 MV at 4.2K, respectively. Two RF windows also passed their specification, 300 kW CW traveling wave and 150 kW CW standing wave. The preliminary tests of SRF cryomodules are reported in the presentation.

WEPPC030

Second Sound Measurement Using SMD Resistors to Simulate Quench Locations on the 704 MHz Single-cell Cavity at CERN

cavity, simulation, linac, quadrupole

2269

K.C. Liao, O. Brunner, E. Ciapala, T. Junginger, W. Weingarten
CERN, Geneva, Switzerland

Oscillating superleak transducers (OSTs) containing a flexible porous membrane are widely used to detect the so-called second sound temperature wave when a quench event occurs in a superconducting RF cavity. In principle, from the measured speed of this wave and the travel time between the quench event and several OSTs, the location of the quench sites can be derived by triangulation. Second sound behavior has been simulated though different surface mount (SMD) resistors setups on a Superconducting Proton Linac (SPL) test cavity, to help understand the underlying physics and improve quench localisation. Experiments are described that have been conducted to search for explanation of heat transfer mechanism during cavity quench that causes contradictory triangulation results.

Poster WEPPC030 [1.473 MB]

WEPPC031

Completed Assembly of the Daresbury International ERL Cryomodule and its Implementation on ALICE

cryomodule, cavity, HOM, controls

2272

P.A. McIntosh, M.A. Cordwell, P.A. Corlett, P. Davies, E. Frangleton, P. Goudket, K.J. Middleman, S.M. Pattalwar, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA
A. Büchner, F.G. Gabriel, P. Michel
HZDR, Dresden, Germany
J.N. Corlett, D. Li, S.M. Lidia
LBNL, Berkeley, California, USA
G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin, V. Veshcherevich
CLASSE, Ithaca, New York, USA
T.J. Jones, J. Strachan
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
D. Proch, J.K. Sekutowicz
DESY, Hamburg, Germany
T.I. Smith
Stanford University, Stanford, California, USA

The completion of an optimised SRF cryomodule for application on ERL accelerators has now culminated with the successful assembly of an integrated cryomodule, following an intensive 5 years of development evolution. The cryomodule, which incorporates 2 x 7-cell 1.3 GHz accelerating structures, 3 separate layers of magnetic shielding, fully adjustable & high power input couplers and fast piezo tuners, has been installed on the ALICE ERL facility at Daresbury Laboratory. It is intended that this will permit operational optimisation for maximised efficiency demonstration, through increased Qext adjustment whilst retaining both effective energy recovery and IR-FEL lasing. The collaborative design processes employed in completing this new cryomodule development are explained, along with the assembly and implementation procedures used to facilitate its successful installation on the ALICE ERL facility.

WEPPC041

Tests of SRF Deflecting Cavities at 2K

cavity, SRF, vacuum, photon

2300

J.D. Fuerst, D. Horan, J. Kaluzny, A. Nassiri, T.L. Smith, G. Wu
ANL, Argonne, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) is developing 2.8-GHz deflecting-mode superconducting rf cavities in collaboration with Jefferson Lab as part of a major facility upgrade. On-site testing of these cavities requires a new cryostat capable of operation at 2.0 K or less. The APS has leveraged facilities and expertise within ANL’s Physics Division to upgrade an existing test stand for continuous operation at temperatures as low as 1.7 K. A new cryogenic feedbox was fabricated and mated to an existing liquid helium “bucket” dewar with 0.6-m inside diameter and 1-m working depth. The configuration allows continuous sub-λ operation using warm vacuum pumping and helium make-up from the Physics Division’s existing cryoplant at heat loads up to 50 W dynamic, plus 15 W measured static load at 2.0 K. A 2.8-GHz TWT-based rf station has been installed and commissioned, providing up to 275 W of rf power. We describe the cryogenic and rf performance of the system and provide examples of cavity test results.

WEPPC075

Testing of the Main-Linac Prototype Cavity in a Horizontal Test Cryomodule for the Cornell ERL

cavity, linac, cryomodule, HOM

2387

N.R.A. Valles, F. Furuta, G.M. Ge, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, M. Tigner, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac (ERL). The cavity construction met all necessary fabrication constraints. After a bulk BCP, 650C outgassing, final BCP, and 120C bake the cavity was vertically tested. The cavity met quality factor and gradient specifications (2·10¹⁰ at 16.2 MV/m) in the vertical test. Progressing with the ERL linac development, the cavity was installed in a horizontal test cryomodule and the quality factor versus accelerating gradient was again measured. This baseline measurement is the first test in a sequence of tests of the main linac cavity in the test cryomodule. Subsequent tests will be with increased complexity of the beam line, e.g. with HOM beamline loads installed, to study potential sources of reducing the cavity’s quality factor.

WEPPC095

Evaluation of Silicon Diodes as In-situ Cryogenic Field Emission Detectors for SRF Cavity Development

cavity, ion, radiation, SRF

2438

A.D. Palczewski, R.L. Geng
JLAB, Newport News, Virginia, USA

Funding: This work is authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We performed in-situ cryogenic testing of five silicon diodes as possible candidates for field emission monitor of SRF cavities in vertical testing dewars and in cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S5821-02 (used at KEK)* and S1223-02; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and their directionality in such environments. We will also present calibration curves between the diodes and JLab’s standard radiation detector placed above the dewar top plate and within radiation shielding.
* H. Sakai et al., Proc of IPAC10, WEPEC028 p. 2950 (2010).

WEPPD002

The Purifier System for Helium Cryogenic Plant in NSRRC

controls, cavity, SRF, synchrotron

2498

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

A cryogenic adsorber is a purifier cooled with liquid nitrogen that is used to trap impurities from gaseous helium in the helium cryogenic system. The output purity can be decreased to less than 5 ppm and the dew point to -62 °C. The maximum rate of flow of each adsorber is 95 Nm3/h. We installed five cryogenic adsorbers in the cryogenic system and completed its testing in 2011; five additional cryogenic adsorbers will be installed in 2012. The configuration, installation, test results and operation of an cryogenic adsorber system are reported herein.
"cryogenic adsorber","purifier"

WEPPD003

Development of a Condenser for the Helium Phase Separator at NSRRC

simulation, vacuum, synchrotron, synchrotron-radiation

2501

C.P. Liu, C.M. Cheng, F. Z. Hsiao, T.Y. Huang, H.H. Tsai
NSRRC, Hsinchu, Taiwan

A helium phase separator with a condenser is under fabrication and assembly at National Synchrotron Radiation Research Center (NSRRC). The objective of a helium phase separator with its condenser is to separate two-phase helium flow and to re-condense vaporized gaseous helium with a cryo-cooler of Gifford-McMahon type. This paper presents the design and fabrication of the condenser, a key component of the helium phase separator. A preliminary steady-state simulation of the efficiency of the helium condenser is also presented.
"Condenser","Rate of condensation"

WEPPD005

SSR1 Cryomodule Design PXIE

cryomodule, vacuum, cavity, solenoid

2504

T.H. Nicol, S. Cheban, M. Chen, S. Kazakov, F. McConologue, Y. Orlov, D. Passarelli, V. Poloubotko, O. Pronitchev, L. Ristori, I. Terechkine
Fermilab, Batavia, USA

Funding: U.S. Department of Energy
Fermilab is planning to design and build a Project X Injector Experiment (PXIE), a cw linac, as a means of validating the Project X concept, reducing technical risks, and obtaining experience in the design and operation of a superconducting proton linac. The overall facility will include an ion source, low and medium-energy beam transport sections, a radio frequency quadrupole, and two cryomodules containing superconducting cavities. One will contain nine half-wave resonators operating at 162.5 MHz and six superconducting solenoids. The second will contain eight single spoke resonators (SSR1) operating at 325 MHz and four superconducting solenoids. This paper describes the design of the cryomodule being developed to house the 325 MHz single spoke resonators. Each of the main cryomodule systems will be described; cryogenic systems and instrumentation, cavity and solenoid positioning and alignment, conduction-cooled current leads, RF input couplers, magnetic shielding, cold-to-warm beam tube transitions, interfaces to interconnecting equipment and adjacent modules, as well as the overall assembly procedure.

WEPPD006

Design of the FRIB Cryomodule

cryomodule, alignment, solenoid, vacuum

2507

M.J. Johnson, M. Barrios, J. Binkowski, S. Bricker, F. Casagrande, A.D. Fox, B.R. Lang, M. Leitner, S.J. Miller, T. Nellis, J.P. Ozelis, X. Rao, J. Weisend, Y. Xu
FRIB, East Lansing, Michigan, USA
D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman
JLAB, Newport News, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
An advanced, modular bottom-supported cryomodule design is described which is highly optimized for mass-production and efficient precision-assembly. The FRIB driver linac uses 4 types of superconducting resonators and 2 solenoid lengths which in turn require 7 individual cryomodule configurations. To meet alignment tolerances a precision-machined bolted cryomodule rail system is described. A novel, kinematic mounting system of the cold mass is introduced which allows for thermal contractions while preserving alignment. A first prototype will incorporate a wire position monitor for alignment verification. The cold alignment structure is supported by composite posts which also function as thermal isolators. The cryogenic system provides separate 2 K and 4.5 K liquid helium lines to cavities and solenoids. Details of the JT valves, heat exchanger, cool-down circuit and junction to cryogenic line will be provided. Transient cool-down was simulated for stresses and buckling failure. A 1100-O Aluminum shield is used as a thermal radiation shield. The paper also describes cryomodule interfaces with the linac tunnel, the RF input cables, and the cryogenic distribution system.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

WEPPD007

Integrated Thermal Analysis of the FRIB Cryomodule Design

cryomodule, vacuum, simulation, radiation

2510

Y. Xu, M. Barrios, F. Casagrande, M.J. Johnson, M. Leitner
FRIB, East Lansing, Michigan, USA
D. Arenius, V. Ganni, W.J. Schneider, M. Wiseman
JLAB, Newport News, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Thermal analysis of the FRIB cryomodule design is performed to determine the heat load to the cryogenic plant, to minimize the cryogenic plant load, to simulate thermal shield cool down as well as to determine the pressure relief sizes for failure conditions. Static and dynamic heat loads of the cryomodules are calculated and the optimal shield temperature is determined to minimize the cryogenic plant load. Integrated structural and thermal simulations of the 1100-O aluminium thermal shield are performed to determine the desired cool down rate to control the temperature profile on the thermal shield and to minimize thermal expansion displacements during the cool down. Pressure relief sizing calculations for the SRF helium containers, solenoids, helium distribution piping, and vacuum vessels are also described.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

WEPPD008

Recondenser Performance: Impact on the Superconducting Undulator Magnet at Argonne National Laboratory

undulator, ion, background, factory

2513

J.M. Pfotenhauer, D.M. Schick
UW-Madison/EP, Madison, Wisconsin, USA

Funding: This work is supported by Argonne National Laboratory, subcontract number 9F-31982.
The current sharing temperature of 6.5 K for the superconducting undulator magnet being developed at Argonne National Laboratory drives the thermal design of the magnet’s cooling system. In order to remain below the current sharing temperature, a thermo-siphon cooling loop is being developed to sweep the anticipated heat load away from the magnet windings and deposit it in the associated liquid helium reservoir located above the magnet. Performance of the magnet’s cooling system is crucially dependent on the ability of the re-condenser to maintain the reservoir’s saturation temperature near 4 K, despite thermal stratification and slowly varying thermal profiles within the vapor region above the liquid in the reservoir. Here we report the results of an experimental investigation of the impact of various geometric configurations for the re-condenser and the thermal resistance associated with the film layer at the re-condensing surface, on the time-varying saturation temperature within the helium reservoir. The resulting temporal thermal variations in the superconducting winding are highlighted as well as the impact they have on the magnet’s stability.

WEPPD029

The Mechanical Design of a Collimator and Cryogenic Bypass for Installation in the Dispersion Suppressors of the LHC

vacuum, superconducting-magnet, shielding, collimation

2567

D. Ramos, L. Alberty Vieira, A. Bertarelli, A. Cherif, N. Chritin, R. Claret, L. Gentini, D. Lombard, P. Minginette, P. Moyret, M. Redondas Monteserin, T. Renaglia, M.A. Timmins
CERN, Geneva, Switzerland

A project to install collimators in the dispersion suppressor regions of the LHC was launched early 2010, aiming to reduce the power deposition in superconducting magnets by a factor of 10. To be placed in the continuous arc cryostat, the design of such collimators had to comply with challenging integration, functional and time constraints. A pre-study for a cold collimator solution was launched in parallel with an alternative design consisting of a room temperature collimator and a cryogenic bypass. The second was eventually preferred, as it was based on proven LHC technologies for cryogenic, vacuum, electrical and collimator material solutions, despite the increased difficulty on the mechanical integration and assembly. This paper presents the mechanical design of a cryogenic bypass for the LHC continuous cryostat and respective collimator unit, both made to comply with the functionality of existing LHC systems. The approach taken to achieve a reliable design within schedule will be explained alongside the measures adopted to validate new solutions, in particular, when dealing with welding distortions, systems routing, thermal loads and precision mechanics.

WEPPD043

The Studies of Power System Harmonics at TLS

coupling, power-supply, dipole, controls

2609

T.-S. Ueng, J.-C. Chang, Y.F. Chiu, K.C. Kuo, Y.-C. Lin
NSRRC, Hsinchu, Taiwan

The power system harmonic distortion in the utility system of NSRRC is investigated for improving the power system performance. The monitored power quality data at the point of common coupling is examined and compared with industrial standards. In addition, the harmonic characteristics of electric power for the accelerator magnets and adjustable speed drives which contribute the most harmonics are analyzed. Furthermore, the approach to mitigate the harmonic effects for improving the power quality is studied.

WEPPD058

The Project-X 3 GeV Beam Distribution System

cavity, kaon, linac, ion

2651

D.E. Johnson, M.H. Awida, M.S. Champion, I.V. Gonin, A.L. Klebaner, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

In the Project X facility, a 3 GeV H⁻ CW beam is delivered to three users simultaneously. This will be accomplished by selectively filling appropriate RF buckets at the front end of the linac and then utilizing a RF splitter to transversely separate bunches to three different target halls. A compact TE113 squashed-wall superconducting RF cavity has been proposed to produce the initial vertical deflection. The transport line optics, cavity design parameters, and cryogenic system requirements will be presented.

WEPPR018

Beam Experiments towards High-intensity Beams in RHIC

proton, injection, vacuum, radiation

2979

C. Montag, L. A. Ahrens, M. Blaskiewicz, J.M. Brennan, K.A. Drees, W. Fischer, T. Hayes, H. Huang, K. Mernick, G. Robert-Demolaize, K.S. Smith, R. Than, P. Thieberger, K. Yip, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Proton bunch intensities in RHIC will be increased from 2*10¹¹ to 3*10¹¹ protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results will be presented.

THEPPB004

Development of a Cryocatcher-System for SIS100

ion, vacuum, heavy-ion, simulation

3237

L.H.J. Bozyk, H. Kollmus, P.J. Spiller
GSI, Darmstadt, Germany

Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI.
The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THPPC039

Study of RF Breakdown in Normal Conducting Cryogenic Structure

impedance, klystron, lattice, accelerating-gradient

3368

V.A. Dolgashev, J.R. Lewandowski, D.W. Martin, S.G. Tantawi, S.P. Weathersby, A.D. Yeremian
SLAC, Menlo Park, California, USA

Funding: *Work supported by DoE, Contract No. DE-AC02-76SF00515.
RF Breakdown experiments on short accelerating structures at SLAC have shown that properties of rf breakdown probability are reproducible for structures of the same geometry. At a given rf power and pulse shape, the rf breakdown triggers continuously and independently at a constant average rate. Hypotheses describing the properties of the rf breakdown probabilities involve defects of metal crystal lattices that move under forces caused by rf electric and magnetic fields. The dynamics of the crystal defects depend on the temperature of the structure. To study the dependence we designed and built an experimental setup that includes a cryogenically cooled single-cell, standing-wave accelerating structure. This cavity will be high power tested at the SLAC Accelerator Structure Test Area (ASTA).

THPPD021

SC Magnet Development for SIS100 at FAIR

quadrupole, dipole, sextupole, multipole

3545

E.S. Fischer, A. Mierau, P. Schnizer
GSI, Darmstadt, Germany

Superconducting magnets have been constructed and tested for the SIS100 (Heavy Ion Synchrotron with a beam rigidity of 100 Tm) of the FAIR project. The requested high quality of the magnetic field as well as the fast periodic ramp of the SIS100 (2T, 1Hz) requires that any source of AC losses is tightly reduced by carefully optimising the 3D geometry of the yoke, choosing the appropriate iron material and minimising the eddy current loops. In addition optimal wire, cable and coil designs have been developed. The residual heat production will be reliable removed by an efficient cooling scheme. The beam pipe vacuum chamber must operate stably as a cryo-pump with surface temperatures below 20K. The electromagnetic, thermal and mechanical aspects were optimised and finally investigated based on physical analysis, supported by FEM calculations and dedicated tests. The results obtained on the main magnets were used for dedicated development of the corrector magnets and their effective integration in the complete cryo-magnet complex of the accelerator. We describe the features of the final magnets next to their optimised fields and present the construction status of the SIS100 magnets.

THPPD027

Consolidation of the 13 kA Splices in the Electrical Feedboxes of the LHC

dipole, quadrupole, controls, superconducting-magnet

3560

A. Perin, S. Atieh, O. Pirotte, R. Principe, D. Ramos, F. Savary, C.E. Scheuerlein, J.Ph. G. L. Tock, A.P. Verweij
CERN, Geneva, Switzerland

In 2008 a defective connection in one of the 13 kA dipole circuits of the LHC caused an electric breakdown that resulted in extensive damage in a sector of the accelerator. The investigation performed after the accident showed the necessity to consolidate the electrical splices of the 13 kA dipole and quadrupole circuits in order to operate the LHC at its nominal energy of 7 TeV. These circuits are powered through electrical feedboxes located at each end of the 8 sectors of LHC. In the feedboxes the current is routed from room temperature to the superconducting magnets along current leads and superconducting busbars and flows through at least two internal splices. These splices are based on the same technologies as the magnet to magnet ones but they are significantly different in terms of environment and configuration. As for the magnet to magnet splices, a consolidation will be necessary to operate them at nominal current. This paper presents an analysis of the properties of these splices and the technologies that will be used to consolidate them. The quality control provisions and the workflow to perform this operation during the first long shutdown of LHC are also presented.

THPPD028

Studies on the LHC Superconducting Circuits and Routine Qualification of Their Functionalities

dipole, collider, hadron, target

3563

M. Pojer, G. D'Angelo, R. Mompo, R. Schmidt, M. Solfaroli Camillocci
CERN, Geneva, Switzerland

The Large Hadron Collider (LHC) is systematically undergoing periods of maintenance stop (either 4-5 days stops or longer Christmas breaks), after which some of the superconducting circuits (or the totality of them) have to be re-commissioned to check the correct functionality of all powering and protection systems. Detailed procedures have been developed during the past few years and they have been optimized to increase powering tests efficiency, thus reducing beam downtime. The approach to the routine qualification of the LHC powering systems is described in this paper. During 2011 technical stops, some particular studies on the superconducting circuits were performed, to assess the quality of the superconducting splices of individually powered magnets and to study the quench propagation in the main magnet bus-bars. The methodology of these tests and some results are also presented.

THPPD029

Machine Availability at the Large Hadron Collider

luminosity, controls, collider, hadron

3566

M. Pojer, R. Schmidt, M. Solfaroli Camillocci, S. Wagner
CERN, Geneva, Switzerland

One of the most important parameters for a particle accelerator is its uptime, the period of time when it is functioning and available for use. In its second year of operation, the Large Hadron Collider (LHC) has experienced very high machine availability, which is one of the ingredients of its brilliant performance. Some of the strategies followed to increase MTBF are described in the paper. The approach of periodic maintenance stops, often questioned, is also discussed. Some considerations on the ideal length of a physics fill are also drawn.

THPPD033

Using Permanent Magnets to Boost the Dipole Field for the High-energy LHC

permanent-magnet, dipole, background, radiation

3578

F. Zimmermann
CERN, Geneva, Switzerland
Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579.
The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb-Ti, Nb3Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability.