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

cryogenics

 
Paper Title Other Keywords Page
MOPCH065 Fabrication and Installation of Superconducting Accelerator Modules for the ERL Prototype (ERLP) at Daresbury vacuum, ERLP, TESLA, linac 178
 
  • P. vom Stein, S. Bauer, M. Pekeler, H. Vogel
    ACCEL, Bergisch Gladbach
  • R. Bate, C.D. Beard, D.M. Dykes, P.A. McIntosh, B. Todd
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  Installation and commissioning of the superconducting energy recovery linac(ERL) prototype is under way at Daresbury Laboratory. ACCEL have manufactured two superconducting accelerator modules for the injector and the linac, operating at 2K with 1.3 GHz TESLA type cavities. Each module contains two cavities and is designed to provide an accelerating voltage of 25 MV in cw mode. This paper presents details of the module fabrication, cavity preparation and performance results. An overview of the cryogenic installations for the modules is given and status results of the commissioning are discussed.  
 
MOPCH072 Adjustable Input Coupler Development for Superconducting Accelerating Cavity simulation, ERL, linac, electromagnetic-fields 193
 
  • M.V. Lalayan, M.A. Gusarova, V.I. Kaminsky, A.A. Krasnov, V.A. Makarov, N.P. Sobenin
    MEPhI, Moscow
  • A.A. Zavadtsev, D.A. Zavadtsev
    Introscan, Moscow
  The waveguide and coaxial-type input couplers for Energy Recovery Linac type injector cavity electrodynamical and thermal simulation results are presented. The devices are designed to feed the superconducting cavity with up to 500 kW RF power in continuous wave regime at 1.3 GHz operating frequency. The cavity external quality factor adjustment is provided. The heat load to the cryogenic system was lowered to a tolerable level by coupler design optimization.  
 
MOPCH093 Design of the Double Electrostatic Storage Ring DESIREE ion, vacuum, storage-ring, simulation 252
 
  • P. Löfgren, G. Andler, L. Bagge, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, A. Paal, K.-G. Rensfelt, A. Simonsson
    MSL, Stockholm
  • H. Cederquist, M. Larsson, S. Rosén, H.T. Schmidt, K. Schmidt
    FYSIKUM, AlbaNova, Stockholm University, Stockholm
  A double electrostatic storage ring named DESIREE is under construction at the Manne Siegbahn Laboratory and Stockholm University. The two rings will have the same circumference, 9.2 m, and a common straight section where merged beam experiments with ions of opposite signs will be performed. The whole structure will be contained in a single vacuum vessel resulting in a very compact design. In addition to its unique double ring structure it will be possible to cool DESIREE down to 10-20K using cryogenerators. This will reduce the internal vibrational and rotational excitations of stored molecules. A cold system will also result in excellent vacuum conditions where longer lifetimes of the stored beams can be expected. While the ion optical calculations have entered a final phase much of the work is now devoted to solve many of the mechanical and cryogenic challenges of DESIREE. In order to test the mechanical and cryogenic properties of for example insulators, vacuum seals, and laser viewports a small test system has been built. The test system is expected to provide valuable information for the final design of DESIREE.  
 
MOPCH142 Commissioning of the SOLEIL RF Systems SOLEIL, controls, CERN, vacuum 384
 
  • P. Marchand, H.D. Dias, M.D. Diop, M.E. El Ajjouri, J.L. Labelle, R.L. Lopes, M. Louvet, C.M. Monnot, J. Polian, F. Ribeiro, T. Ruan, R.S. Sreedharan, K. Tavakoli, C. Thomas-Madec
    SOLEIL, Gif-sur-Yvette
  • P. Bosland, P. Bredy
    CEA, Gif-sur-Yvette
  The 352 MHz RF accelerating systems for the SOLEIL Booster (BO) and Storage Ring (SR) are being commissioned. In the BO a 5-cell copper cavity of the CERN-LEP type is powered with a 35kW solid state amplifier. In the SR the required RF accelerating voltage (up to 4.4MV) will be provided by two cryomodules, each containing a pair of superconducting cavities, specifically designed for SOLEIL. The parasitic impedances of the high order modes are strongly attenuated by means of four coaxial couplers, located on the tube connecting the two cavities. The first cryomodule is already installed in the SR tunnel, while the second one is being constructed by ACCEL (Germany). These cryomodules are supplied in liquid helium from a single 350W liquefier and each cavity is powered with a 190kW solid state amplifier. The RF system commissioning and first operation results are reported.  
 
MOPCH143 Electromechanical Characterization of Piezoelectric Actuators Subjected to a Variable Preloading Force at Cryogenic Temperature vacuum, simulation, target, linac 387
 
  • M. Fouaidy, N. Hammoudi, M.S. Saki, H. Saugnac, L. Simonet
    IPN, Orsay
  Piezoelectric actuators are actually used in Fast Active Cold Tuning Systems (FACTS) for SRF cavities. The characteristics, performances and lifetime of these actuators depend on the preloading force applied by the cavity and the FACTS to the piezostacks. Experimental data are needed for reliable and optimum operation of piezostacks in superconducting protons or electrons linacs. In the frame of the CARE project supported by EU, we designed and constructed a dedicated apparatus for studying the electromechanical behavior of prototype piezoelectric actuators subjected to variable preloading force at cryogenic temperatures. This device was successfully used for testing piezoelectric actuators prototypes for T in the range 2K-300K. The dielectric properties as well as dynamic properties were measured including the actuator characteristics when used as force sensor. The corresponding data are reported and discussed.  
 
MOPCH146 Status of the Beta 0.12 Superconducting Cryomodule Development for the Spiral2 Project SPIRAL2, linac, alignment, controls 396
 
  • H. Saugnac, J.-L. Biarrotte, S. Blivet, S. Bousson, C. Commeaux, C. Joly, T. Junquera, J. Lesrel, fl. Lutton, G. Martinet, G. Olry, P. Szott
    IPN, Orsay
  SPIRAL2 is a radioactive beams facility, composed of a superconducting linac driver, delivering deuterons with an energy up to 40 MeV (5 mA) and heavy ions with an energy of 14.5 MeV/u (1 mA). This facility is now fully approved by the French government. IPN Orsay is in charge of the study and manufacture of the beta 0.12 cryomodule of the superconducting LINAC. These cryomodule, designed for an overall cryogenic power of 30 W at 4.2 K, is composed of two quarter wave type 88 MHz rf resonator providing a minimum of 6.5 MV/m with a quality factor of 1 10 9, two tuning mechanisms controlling the resonator frequency and an alignment system allowing to adjust the cavity position with a ± 1 mm accuracy. Several tests performed on a first resonator prototype fabricated by the "Ettore Zanon SpA" Company, have validated the cavity and its auxiliary components design. A first cryomodule fully equipped (cavities, cryostat, tuning and alignment systems), planned to be tested at the beginning of 2007, is under manufacturing. The details of the cryomodule design and the resonator tests results are discussed in the paper.  
 
MOPCH148 First RF Tests in the HoBiCaT Superconducting Test Facility at BESSY vacuum, TESLA, electron, controls 402
 
  • O. Kugeler, W. Anders, J. Borninkhof, H.G. Hoberg, S. Klauke, J. Knobloch, M. Martin, G. Mielczarek, A. Neumann, D. Pflückhahn, S. Rotterdam, M. Schuster, T. Westphal
    BESSY GmbH, Berlin
  In preparation for the construction of the BESSY-FEL User Facility, BESSY recently completed the installation of the HoBiCaT cryogenic test facility for superconducting RF (SRF) TESLA cavity units, including all ancillary devices (helium tank, input coupler, tuner, magnetic shielding). It is designed to house two such units in a configuration similar to that envisaged for the superconducting CW linac of the BESSY FEL. Commissioning of the facility is now complete and the first TTF-III RF coupler and cavity unit have been tested. In particular, the complete production, cleaning and assembly of the cavity unit was carried out by industry. These tests thus serve as a first step at qualifying industrial partners for series production of such systems, which will be essential for the future construction of SRF based light sources. Results will be presented.  
 
MOPCH149 Microphonics Measurements in a CW-driven TESLA-type Cavity resonance, klystron, pick-up, linac 405
 
  • O. Kugeler, W. Anders, J. Knobloch, A. Neumann
    BESSY GmbH, Berlin
  Superconducting cavities with a high quality factor exhibit a very low bandwidth in their resonant frequency, which makes their operation very sensitive to mechanical oscillations. In CW mode of operation, as is intended for the BESSY-FEL Linac, microphonics are therefore the dominant error source for field stability. In order to compensate the detuning, it is necessary to properly characterize amplitude and frequency with respect to all involved mechanical and electrical components. Such measurements have been performed at the HoBiCaT test facility at BESSY and will be described in detail.  
 
MOPCH153 Peak Field Optimization for the Superconducting CH Structure simulation, linac, impedance, GSI 415
 
  • H. Liebermann, H. Podlech, U. Ratzinger
    IAP, Frankfurt-am-Main
  The Cross-Bar H-type (CH) cavity is a multi-gap drift tube structure operated in the H-210 mode which has been developed at the IAP Frankfurt and in collaboration with GSI. Based on detailed numerical simulations a 19 cell prototype cavity from massive Nb was realised. For optimization of the magnetic and electric peak fields, detailed numerical simulations with CST MicroWave Studio have been performed. After successful experiments on the superconducting prototype cavity calculations about improved drift tube geometries with respect to field emission took place. Additionally, the stem geometry was further improved by simulations.  
 
MOPCH167 PBG Superconducting Resonant Structures lattice, pick-up, radiation, simulation 454
 
  • M.R. Masullo
    INFN-Napoli, Napoli
  • A. Andreone, E. Di Gennaro, F. Francomacaro, G. Lamura
    Naples University Federico II, Napoli
  • V. Palmieri, D. Tonini
    INFN/LNL, Legnaro, Padova
  • M. Panniello, V.G. Vaccaro
    Naples University Federico II and INFN, Napoli
  We have realized normal conducting and superconducting “open resonators” based on the Photonic Band Gap (PBG) concept. We present the study, the optimisation and the measurements (from room temperature to 1.5 K) of Copper and Niobium PBG accelerating cavities operating at two different frequencies, 6 GHz and 16 GHz. All the structures are realised by extruding a single bulk piece of material, using a new machining method that minimizes the surface losses caused by the contact between different conducting parts. Measurements on the compact (54 mm external diameter) 16 GHz Nb structure are very good, showing in the superconducting state a quality factor Q =1.2x105 at the lowest temperature (1.5 K), limited by radiation losses only. The shunt impedance measured for the 16 GHz prototype is 70 MOhm/m, underlining the applicability of such resonant structures as accelerating cavities.  
 
MOPCH170 Experimental and Theoretical Analysis of the Tesla-like SRF Cavity Flanges TTF, vacuum, TESLA, collider 463
 
  • L. Monaco, P. Michelato, C. Pagani, N. Panzeri
    INFN/LASA, Segrate (MI)
  In view of the future large SC accelerator, an improvement of the reliability and a cost reduction of the SRF cavities cold flanges is required. In this paper, a critical analysis of the TESLA-like cold connection flanges at room and at cryogenic temperature is presented. This analysis is based on experimental characterization of the mechanical properties of the joint and of the leak rates during the sealing process. A FEM model, that agrees with the experimental data, is also presented. This model is being used for the optimization of the present SRF flanges and the development of new cold connections.  
 
MOPCH176 A Comparison of Large Grain and Fine Grain Cavities Using Thermometry superconductivity, site, superconducting-RF 475
 
  • G.V. Eremeev, H. Padamsee
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  An important limitation for SRF niobium cavities is the ”high field Q-slope.” To investigate this phenomenon we compare the behavior of large grain and fine grain cavities using thermometry. Thermometry allows us to distinguish between different problems which occur in cavities, and to distinguish between different areas showing high field Q-slope. We looked for the difference in heating between grain boundaries and inside grains. We have found interesting differences between the heating of high field slope regions and the heating of point-like defects.  
 
MOPCH178 Tests on MgB2 for Application to SRF Cavities laser, SLAC, target, LANL 481
 
  • T. Tajima
    LANL, Los Alamos, New Mexico
  • I.E. Campisi
    ORNL, Oak Ridge, Tennessee
  • A. Canabal-Rey
    NMSU, Las Cruces, New Mexico
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • B. Moeckly
    STI, Santa Barbara, California
  • C.D. Nantista, S.G. Tantawi
    SLAC, Menlo Park, California
  • H.L. Phillips
    Jefferson Lab, Newport News, Virginia
  • A.S. Romanenko
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • Y. Zhao
    University of Wollongong, Institute of Superconducting and Electronic Materials, Wollongong
  Magnesium diboride (MgB2) has a transition temperature (Tc) of ~40 K, i.e., about four times higher than niobium (Nb). The studies in the last three years have shown that it could have about one order of magnitude less RF surface resistance (Rs) than Nb and seems much less power dependent compared to high-Tc materials such as YBCO. In this paper we will present results on the dependence of Rs on surface magnetic fields and possibly the critical RF surface magnetic field.  
 
MOPCH187 Key Cryogenics Challenges in the Development of the 4GLS linac, TESLA, FEL, ERLP 499
 
  • R. Bate, R.K. Buckley, A.R. Goulden, C. Hodgkinson, S.M. Pattalwar
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  The fourth generation light source (4GLS) is a uniquely flexible source of ultra-high brightness continuous and pulsed radiation covering the IR to XUV range of the spectrum. It is the first light source in the world that is planned from the outset to be a multi-user, multi-source facility combining ERL (energy recovery LINAC) and FEL (free electron laser) technology. 4GLS will require six different sets of superconducting LINACs. Each of the LINAC modules consists of 2 to 7, 1.3 GHz superconducting RF cavities of the TESLA design operating at 1.8 K. The overall cooling power necessary to cool the cavities is estimated to be around 2.5KW demanding the superfluid liquid helium flow rates in excess of 200g/s. Even though the technology of the superconducting RF cavities is somewhat well understood, the design and subsequent operation of the cryogenic system / Cryo modules is an extremely complex task. In this paper we describe the key cryogenic challenges of the 4GLS project and our approach in identifying solutions to meet them.  
 
MOPCH189 Calculating the Muon Cooling within a MICE Liquid Absorber scattering, emittance, factory, focusing 502
 
  • M.A. Green, S.P. Virostek
    LBNL, Berkeley, California
  • S.Q. Yang
    OXFORDphysics, Oxford, Oxon
  The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also well understood. The properties of solid absorber are most certainly understood to 0.3 percent. The MICE liquid absorbers are different in that their dimensions are a function of the absorber temperature and the fluid pressure within the absorber. The second element in the liquid absorber is the variability of the liquid density with temperature and pressure. While one can determine the absorber boundary within 0.3 percent, the determination of the liquid density within 0.3 percent is more difficult (particularly with liquid helium in the absorber). This report presents a method of calculating absorber boundary and the cooling performance of the MICE absorbers as a function of fluid temperature and pressure.  
 
MOPCH191 Copper Heat Exchanger for the External Auxiliary Bus-bars Routing Line in the LHC Insertion Regions LHC, CERN, quadrupole, insertion 508
 
  • C. Garion, A. Poncet, F. Seyvet, J.-P.G. Tock
    CERN, Geneva
  • M. Sitko, B. Skoczen
    CUT, Krakow
  The corrector magnets and the main quadrupoles of the LHC dispersion suppressors are powered by a special superconducting line (called auxiliary bus-bars line N), external to the cold mass and housed in a 50 mm diameter stainless steel tube fixed to the cold mass. As the line is periodically connected to the cold mass, the same gaseous and liquid helium is used for cooling the magnets and the line. The final sub-cooling process (from 4.5 K down to 1.9 K) consists of the phase transformation from liquid to superfluid helium. It is slightly delayed with respect to the magnets. To accelerate the process, a special heat exchanger has been designed. Located in the middle of the dispersion suppressor portion of the line it consists in creating a local sink of heat extraction, providing two additional λ fronts that propagate in opposite directions towards the line extremities. Both the numerical model and the sub-cooling analysis are presented in the paper for different configurations of the line. Design, manufacturing and integration aspects of the heat exchanger are described. Finally, the results of the qualification tests and the expected performance of the line are given.  
 
MOPCH192 Operation of a Helium Cryogenic System for a Superconducting Cavity in an Electron Storage Ring controls, superconducting-magnet, electron, storage-ring 511
 
  • F. Z. Hsiao, S.-H. Chang, W.-S. Chiou, H.C. Li
    NSRRC, Hsinchu
  A 500 MHz superconducting cavity maintaining the energy of electrons in the storage ring of TLS light source started from the year 2005. A helium system dedicated to keep the niobium cavity at 4.5 K has begun its operation since the year 2003. The cryogenic system provides maximum refrigeration of 469 W or liquefaction rate of 134 l/hr. The constraint from the superconducting cavity leads to specific features of the cryogenic system. This paper presents the operation of the cryogenic system as the superconducting cavity at different conditions. The interaction in between the cryogenic system and the superconducting cavity and the constraints on the starting and shutdown of the cryogenic system are indicated.  
 
MOPCH193 SNS 2.1K Cold Box Turn-down Studies SNS, controls, linac, SLAC 514
 
  • F. Casagrande, P.A. Gurd, D.R. Hatfield, M.P. Howell, W.H. Strong
    ORNL, Oak Ridge, Tennessee
  • D. Arenius, J. Creel, V. Ganni, P. Knudsen
    Jefferson Lab, Newport News, Virginia
  The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is nearing completion. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The 2.1K cold box consists of four stages of centrifugal compressors with LN2-cooled variable speed electric motors and magnetic bearings. The cryogenic system successfully supported the Linac beam commissioning at both 4.2K and 2.1K and has been fully operational since June 2005. This paper describes the control principles utilized and the experimental results obtained for the SNS cold compressors turn-down capability to about 30% of the design flow, and possible limitation of the frequency dependent power factor of the cold compressor electric motors, which was measured for the first time during commissioning. These results helped to support the operation of the Linac over a very broad and stable cold compressor operating flow range (refrigeration capacity) and pressure. This in turn helped to optimise the cryogenic system operating parameters, minimizing the utilities and improving the system reliability and availability.  
 
MOPLS118 Magnetic Modelling of a Short-period Superconducting Helical Undulator for the ILC Positron Source undulator, positron, TESLA, photon 840
 
  • J. Rochford, E. Baynham, T.W. Bradshaw, F.S. Carr
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • I.R. Bailey, L.I. Malysheva
    Cockcroft Institute, Warrington, Cheshire
  • D.P. Barber
    DESY, Hamburg
  • A.J. Brummitt, Y. Ivanyushenkov
    CCLRC/RAL, Chilton, Didcot, Oxon
  • J.A. Clarke, O.B. Malyshev, D.J. Scott
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • P. Cooke, J.B. Dainton
    Liverpool University, Science Faculty, Liverpool
  • G.A. Moortgat-Pick
    Durham University, Durham
  A positron source utilising undulators is now defined as the baseline option for the International Linear Collider (ILC). The ILC requires a short period undulator, as close to 10mm as possible, that is capable of producing 10 MeV photons. The HeliCal collaboration in the UK has undertaken a programme to design, develop and produce a prototype undulator. As part of the programme, the group has used the OPERA software package to perform the magnetic design of the undulator. The design has addressed several issues, including the effect of magnetic material for the undulator former, optimal winding geometry, the magnetic flux inside the superconductor and its variation with undulator period and the winding bore. This paper summarizes the results of both the 2d and the 3d magnetic simulations.  
 
TUPCH011 Innovative Beam Diagnostics for the Challenging FAIR Project diagnostics, synchrotron, ion, feedback 1016
 
  • P. Forck, A. Peters
    GSI, Darmstadt
  The planned FAIR facility consists of two heavy ion synchrotrons and four large storage rings. The super-conducting synchrotrons are build for high current operation and secondary ion production. A large variety of low current secondary beams is stored and cooled in the four storage rings. A complex operation scheme with multiple use of transport lines is foreseen. This demands an exceptional high dynamic range for the beam instrumentation. Due to the enormous beam power, non-destructive methods are mandatory for high currents. For the low current secondary beams, non-destructive diagnostics are also preferred due to the low repetition rate. Precise measurements of all beam parameters and automatic steering or feedback capabilities are required due to the necessary exploitation of the full ring acceptances. Moreover, online beam-corrections with short response times are mandatory for the fast ramping super-conducting magnets. Due to the ultra-high vacuum condition and the demanding measurement accuracy, novel technical solution are foreseen. An overview of the challenges and projected innovative solutions for various diagnostic installations will be given.  
 
TUPCH031 A New SQUID-based Measurement Tool for Characterization of Superconducting RF Cavities pick-up, electron, shielding, TESLA 1070
 
  • K. Knaack, K. Wittenburg
    DESY, Hamburg
  • R. Neubert, S. Nietzsche, W. Vodel
    FSU Jena, Jena
  • A. Peters
    GSI, Darmstadt
  In this contribution a LTS-SQUID based measurement tool for characterization of superconducting RF cavities for the upcoming X-FEL project at DESY will be presented. The device makes use of the Cryogenic Current Comparator (CCC) principle and measures the so-called dark current, generated e.g. by superconducting cavities at high voltage gradients. To achieve the maximum possible energy the gradients should be pushed near to the physical limit of 50 MV/m. The measurement of the undesired field emission of electrons (the so-called dark current) in correlation with the gradient will give a proper value to characterize the performance of the RF cavities. The CCC mainly consists of a high performance LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted dark current of the RF cavities. Therefore, a special designed toroidal niobium pick-up coil for the passing electron beam is superconducting connected across the input coil of the SQUID. The noise limited sensitivity of the CCC as well as new experimental results with the whole measurement device assembled in a special wide-necked LHe cryostat will be presented.  
 
TUPCH042 The Optical System for a Smith-Purcell Experiment at 45MeV radiation, background, vacuum, electron 1097
 
  • V. Blackmore, W.W.M. Allison, G. Doucas, C. Perry
    OXFORDphysics, Oxford, Oxon
  • P.G. Huggard
    CCLRC/RAL, Chilton, Didcot, Oxon
  • M.B. Johnston
    University of Oxford, Clarendon Laboratory, Oxford
  • B. Redlich, A.F.G. van der Meer
    FOM Rijnhuizen, Nieuwegein
  Smith-Purcell (SP) radiation has been used to investigate the longitudinal profile of a 45MeV, picosecond long bunched beam at the FELIX facility, FOM Institute. The three important optical elements that made this experiment possible were (i) high quality optical filters, (ii) nonimaging light concentrators, (iii) and a system to rapidly change between gratings.  
 
TUPCH175 The Vacuum System of FAIR Accelerator Facility vacuum, ion, cathode, quadrupole 1429
 
  • A. Kraemer, M.C. Bellachioma, H. Kollmus, H.R. Sprenger, St. Wilfert
    GSI, Darmstadt
  The FAIR accelerator complex consists of two superconducting synchrotrons (SIS100 and SIS300) with a circumference of 1083.6m each, a high energy beam transport system (HEBT) with a total length of about 2.5km and four storage rings (CR, RESR, HESR and NESR). Their length varies between 200m and 550m. For each of the subsystems, different vacuum requirements have to be fulfilled. The vacuum system of SIS100 and SIS300 consists of cryogenic and bakeable room temperature sections, where a pressure in the lower 10-12 mbar range is needed. For HEBT, also a combination of cryogenic and room temperature sections, a vacuum pressure of 10-9 mbar is sufficient. The storage rings will be operated in a pressure range from 10-9 mbar to 10-12 mbar. In the poster a detailed layout of the vacuum systems and technical solutions will be presented.  
 
TUPLS042 First Cryogenic Tests of the Superconducting CH-structure GSI, pick-up, resonance, coupling 1588
 
  • H. Podlech, C. Commenda, H. Klein, H. Liebermann, U. Ratzinger, A.C. Sauer
    IAP, Frankfurt-am-Main
  The CH-structure is a new multi-cell drift tube structure operated in the TE21-mode and is well suited for the acceleration of low and medium beta ion and proton beams. Due to the mechanical stiffness room temperature as well as superconducting CH-cavities can be realised. A 19-cell, beta=0.1 superconducting CH-prototype cavity has been developed and built. First cryogenic tests have been performed at 4.5 K in Frankfurt successfully. An effective accelerating voltage of 3.6 MV has been achieved so far. This corresponds to an electric peak field of 23 MV/m. Actual measurements aim on a localisation of possible field emission centers, afterwards further surface preparation will take place.  
 
TUPLS045 Completion of the Commissioning of the Superconducting Heavy Ion Injector PIAVE at INFN-LNL emittance, ion, rfq, booster 1597
 
  • G. Bisoffi, G. Bassato, A. Battistella, l. Boscagli, A. Calore, S. Canella, D. Carlucci, M. Cavenago, F. Chiurlotto, M. Comunian, M. De Lazzari, A. Facco, E. Fagotti, A. Galatà, P. Modanese, M.F. Moisio, A. Pisent, M. Poggi, A.M. Porcellato, P.A. Posocco, C. Roncolato, E. Sattin, S. Stark
    INFN/LNL, Legnaro, Padova
  • N. Schiccheri
    CNAO Foundation, Milan
  At INFN-LNL the commissioning of the injector PIAVE, based on superconducting RFQs, has been completed. All the superconducting cavities (two RFQs and 8 quarter wave resonators - QWR) have shown very satisfactory stability with respect to changes of the liquid helium pressure and microphonics. Beam parameters are very close to the nominal values. The commissioning was completed by accelerating the pilot beam 16O3+ with the PIAVE injector and the booster linac ALPI (summer 2005). Since December 2005, a number of test beams were accelerated (mainly noble gas species) with PIAVE and ALPI and delivered to user experimental stations. Regular operation will be scheduled from Fall 2006 onwards.  
 
WEPLS099 Fault Detection and Identification Methods Used for the LHC Cryomagnets and Related Cabling impedance, LHC, diagnostics, superconducting-magnet 2607
 
  • D. Bozzini, F. Caspers, V. Chareyre, Y. Duse, T. Kroyer, R. Lopez, A. Poncet, S. Russenschuck
    CERN, Geneva
  Several non-standard methods for electrical fault location have been successfully developed and tested. As part of the electrical quality assurance program, certain wires have to be subjected to a (high) DC voltage for the testing of the insulation. With the time difference of spark-induced electromagnetic signals measured with an oscilloscope, fault localization within a ± 10 cm range has been achieved. Another method used and adapted for the particular needs, was the synthetic pulse time-domain reflectometry (TDR) by means of a vector network analyzer. This instrument has also been applied as a low frequency sweep impedance analyzer in order to measure fractional capacities of cable assemblies where TDR was not applicable.  
 
THPCH169 Design, Manufacturing and Integration of LHC Cryostat Components: an Example of a Collaboration between CERN and Industry CERN, vacuum, LHC, controls 3191
 
  • M. Canetti, F.G. Gangini
    RIAL VACUUM S.p.A, Parma
  • N. Bourcey, T. Colombet, V. Parma, I. Slits, J.-P.G. Tock
    CERN, Geneva
  The components for the LHC cryostats and interconnections are supplied by the European industry. The manufacturing, assembly and testing of these components in accordance with CERN technical specifications require a close collaboration and dedicated approach from the suppliers. This paper presents the different phases of design, manufacturing, testing and integration of four LHC cryostat components supplied by RIAL Vacuum (Parma, Italy), including 108 insulation vacuum barriers, 482 cold-mass extension tubes, 115 cryostat vacuum vessel jumper elbows and 10800 interconnection sleeves. The Quality Assurance Plan, which the four projects have in common, is outlined. The components are all leak-tight thin stainless steel assemblies (< 10-8 mbar l/s), most of them operating at cryogenic temperature (2 K), however each having specific requirements. Therefore the peculiarities of each component are presented with respect to manufacturing, assembly and testing. These components are being integrated at CERN into the LHC cryostats and interconnections, which allowed validating the design and production quality. The major improvements and difficulties will be discussed.  
 
THPCH171 Control System of the Superconducting Insertion Device at TLS controls, power-supply, insertion, insertion-device 3197
 
  • J. Chen, K.-T. Hsu, S.Y. Hsu, K.H. Hu, C.H. Kuo, D. Lee, C.-J. Wang
    NSRRC, Hsinchu
  There are three superconducting insertion devices installed at Taiwan Light Source. Two is under construction. These insertions enhance hard X-ray production to satisfy the research requirement of X-ray community. The control system is implemented to support the operation of all these superconducting insertion devices. The control system coordinate the operation of the main power supply and the trimming power supply to charge/discharge the magnets and provide essential interlock protection for the coils and vacuum ducts. Friendly user interface supports routine operation. Various applications are also developed to aid the operation of these insertion devices. Design consideration and details of the implementation will be summary in this report.  
 
THPCH183 Installation and Quality Assurance of the Interconnections between Cryo-assemblies of the LHC Long Straight Sections LHC, CERN, vacuum, controls 3227
 
  • C. Garion, I. Slits, J.-P.G. Tock
    CERN, Geneva
  The interconnections between the cryomagnets and cryogenic utilities in the LHC long straight sections constitute the last machine installation activity. They are ensuring continuity of the beam and insulation vacuum systems, cryogenic fluid and electrical circuits and thermal insulation. The assembly is carried out in a constraining tunnel environment with restricted space. Therefore, the assembly sequence has to be well defined, and specific tests have to be performed during the interconnection work to secure the reliability of the system and thus to ensure the global accelerator availability. The LHC has eight long straight insertion zones composed of special cryomagnets involving specific interconnection procedures and QA plans. The aim of this paper is to present the installation and quality assurance procedures implemented for the LHC LSS interconnections. Technologies such as manual and automatic welding and resistive soldering will be described as well as the different quality controls such as visual and radiographic inspection of welds, electrical and leak testing. An evaluation and statistical analysis of the results of the interconnection work will be presented.  
 
THPCH185 Planning and Logistics Issues Raised by the Individual System Tests during the Installation of the LHC LHC, instrumentation, vacuum, superconducting-magnet 3233
 
  • S. Weisz, E. Barbero-Soto, K. Foraz, F. Rodriguez-Mateos
    CERN, Geneva
  The running of individual system tests has to fit within tight constraints of the LHC installation planning and of CERN's accelerator activity in general. For instance, the short circuit tests of the power converters that are performed in situ restrict the possibility to work in neighbouring areas; much in the same way, the cold tests of the cryogenic distribution line involve safety access restrictions that are not compatible with the transport and installation of cryo-magnets or interconnect activities in the sector considered. Still, these individual system tests correspond to milestones that are required to ensure that we can continue with the installation of machine elements. This paper reviews the conditions required to perform the individual system tests and describe how the general LHC installation planning is organised to allocate periods for these tests.  
 
THPCH197 Analysis of Availability and Reliability in RHIC Operations RHIC, controls, luminosity, ion 3257
 
  • F.C. Pilat, P. Ingrassia, R.J. Michnoff
    BNL, Upton, Long Island, New York
  RHIC has been successfully operated for five years as a collider for different species, ranging from heavy ions including gold and copper, to polarized protons. We present a critical analysis of reliability data for RHIC that not only identifies the principal factors limiting availability but also evaluates critical choices at design times and assess their impact on present machine performance. RHIC availability data are compared to similar high-energy colliders and synchrotron light sources. The critical analysis of operations data is the basis for studies and plans to improve RHIC machine availability beyond the 60% typical of high-energy collider.  
 
THPLS119 Development of a Cryogenic Permanent Magnet In-vacuum Undulator at the ESRF undulator, ESRF, vacuum, permanent-magnet 3559
 
  • C.A. Kitegi, J. Chavanne, D. Cognie, P. Elleaume, C. Penel, B. Plan, F. Revol, M. Rossat
    ESRF, Grenoble
  Lowering the temperature of NdFeB materials increases their field remanence and intrinsic coercivity*. This property is potentially interesting for the construction of cryogenic permanent in-vacuum undulators (CPMU)**. Around 150K, the coercivity is increased to such an extent that the NdFeB material is comparable to the Sm2Co17 as far as resistance to radiation damages is concerned. The improvement in field remanence is less remarkable (15% at 150K) and is dominated by a reversible Spin Reorientation Transition (SRT) occurring around 135K. Below this temperature, the remanence decreases. The complete magnetization curves of NdFeB material measured at different cryogenic temperatures are presented. Non-linear models have been constructed and used in the RADIA code in order to compute the field performance of a hybrid NdFeB in-vacuum undulator. A prototype CPMU is presently under construction at the ESRF. It has a period of 18mm and a magnetic length of 2m. The field integral and local field measurements of the cryogenic device require new systems operated in vacuum. A stretched wire bench and a hall probe bench are under construction; their main characteristics will be presented.

*D. Givord et al. Analysis of hysteresis loops in NdFeB sintered magnets, J. Appl. Phys. 60(9) (3263-3265).**T. Hara et al. Cryogenic permanent undulator, Phys.rev. ST AB volume 7 050702 (2004).

 
 
THPLS139 In-Achromatic Superconducting Wiggler in Taiwan Light Source: Installation and Test Results wiggler, storage-ring, vacuum, electron 3613
 
  • C.-H. Chang, C.-C. Chang, H.-P. Chang, H.-H. Chen, J.-R. Chen, T.-C. Fan, G.-Y. Hsiung, M.-H. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin
    NSRRC, Hsinchu
  In order to increase more high flux x-ray photon beams for the Taiwan Light Source, the achromatic superconducting wiggler has been installed and tested in a 1.5 GeV storage ring. The 3.1 Tesla superconducting wiggler will be operated in a 4.5 K liquid helium cryogenic system. In this work, the operation experience and test results of the achromatic superconducting wiggler are described.  
 
FRXCPA01 Design, Construction, Installation and First Commissioning Results of the LHC Cryogenic System LHC, CERN, controls, collider 3626
 
  • S.D. Claudet
    CERN, Geneva
  The cryogenic system of the Large Hadron Collider (LHC) will be, upon its completion in 2006, the largest in the world in terms of refrigeration capacity with 140 kW at 4.5 K, distributed superfluid helium with 25 km of superconducting magnets below 2 K and cryogen inventory with 100 tons of Helium. The challenges involved in the design, construction and installation, as well as the first commissioning results will be addressed in this talk. Particular mention will be made of the problems encountered and how they were or are being solved. Perspectives for LHC will be presented. General considerations for future large cryogenic systems will be briefly proposed.  
slides icon Transparencies