• L.O. Dallin, D.G. Bilbrough
  CLS, Saskatoon, Saskatchewan

Storage rings require corrector magnets for a variety of tasks. Foremost are small dipole magnets for both horizontal and vertical correction. In light sources, for example, other corrector magnets are needed to compensate for the effect of changing insertion device operation points. These can include quadrupole, skew quadrupole, sextupole and skew sextupole corrections. As well octupole magnets may be desirable to improve dynamic aperture in small emittance lattices. One magnet can perform all these tasks. This is achieved by having separate windings with separate power supplies on an octopole yoke. The simultaneous excitation of any combination of modes can be achieved through superposition. Corrections are necessarily limited to avoid saturation effects that will degrade the superposition.

• K. Flöttmann
  DESY, Hamburg

Printed circuit boards offer a simple method for the design of hysteresis free, compact air coil magnets. The emphasis for the steering magnets developed for the FLASH injector is placed on a high integrated field strength for a short magnetic length to cope with space limitations in the injector beam line. The possibility to combine a pair of orthogonal steerers at the same longitudinal position has been realized by two layers of printed circuit boards. Design principles and magnetic measurements will be discussed.

• C. Priano, G. Bazzano, D. Bianculli, E. Bressi, I. De Cesaris, M. Pullia
  CNAO Foundation, Milan
• M.C.L. Buzio, R. Chritin, D. Cornuet, J.M. Dutour, L. Vuffray
  CERN, Geneva
• E. Froidefond
  LPSC, Grenoble
• C. Sanelli
  INFN/LNF, Frascati (Roma)

CNAO is a synchrotron accelerator presently under commissioning in Pavia. The aim of this accelerator is to treat tumors with hadrons and to perform advanced clinical and radiobiological research. The CNAO will start treating patients with protons (60-250 MeV range) and carbon ions (120-400 MeV/u range) in three treatment rooms with four beam lines. Future upgrade with gantries is foreseen. This paper describes the design, magnetic measurements and sorting criterion used for the sixteen synchrotron main dipoles and twenty-four quadrupoles. The magnetic measurements results are compared with magnetic simulation.

• G. Bazzano
  CNAO Foundation, Milan

The National Centre for Oncological Hadrontherapy (CNAO) will be the first Italian facility for the treatment of deep located tumours with proton and carbon ion beams and active scanning technique. The accelerator complex consists of an injection system, a synchrotron and 5 extraction lines. By the end of 2009 the ECR sources, Low Energy Transfer Line (LEBT), RFQ and LINAC where fully commissioned; in December injection and first turns in the synchrotron were also successfully achieved. Full installation of machine and extraction lines was completed in early 2010. The recent advances in the commissioning and performance of the CNAO complex are being reported in this contribution.

• S. Hanada
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima
• A. Miyamoto, S. Sasaki
  HSRC, Higashi-Hiroshima

The HiSOR-II is a storage ring planned as a successive machine of HiSOR, a present ring at Hiroshima Synchrotron Radiation Center. This accelerator has the circumference equal to or less than 50 m, and it has the emittance about 14 nm-rad and aims at the beam energy of 700 MeV. In the HiSOR-II project, we decided to adopt electromagnets with combined function. This type magnet has an advantage for constructing a small storage ring by reducing the total number of magnet, though it has a difficulty for the independent tuning of multipole field components. In addition,　we decided to share a single return yoke between a bending magnet and adjacent quadrupole magnets. In this paper, we discuss about a possible magnetic interference between a bending magnet and a quadrupole magnet. Calculation is made with magnetic field simulation cord RADIA to analyze interference effect and examine the possibility of adoption to HiSOR-II storage ring. Also, we perform the tracking simulation of the beam with the mapping data of a magnetic field provided by this three-dimensional magnetic field analysis. By the simulation, the dynamic aperture is determined.

• Y. Shoji
  NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo

A multi-element octupole-base corrector magnet is designed and fabricated. The new corrector magnet will be installed in the electron storage ring NewSUBARU in place of vertical steering (skew dipole) magnets. It has coil windings to produce skew quadrupole, skew sextupole, normal octupole, and the skew dipole field. The skew dipole element is used to achieve vertical steering. The skew quadrupole and the skew sextupole elements are for the resonance correction. The normal octupole element is used to control the higher order dispersion function and the higher order momentum compaction factor. In this design the main coil is wound around the return yoke instead of the pole. We expect improvement of the beam lifetime and injection efficiency during normal operation as well as improved isochronism during extreme quasi-isochronous operation. In designing the magnet, careful consideration is given to field interference caused by a neighboring magnet, set close to the corrector magnet of comparable yoke and bore diameter dimensions. The magnetic field with field interference is calculated using OPERA-3D.

• K. Egawa, M. Masuzawa
  KEK, Ibaraki

The KEKB is a high luminosity accelerator which achieved the highest luminosity record of 2.1x10³⁴. It requires the precise and stable beam control to keep its high luminosity continually. Slight change of the magnetic field may easily deteriorate the performance of the collisions of the very small and thin beams. The field measurement accuracy better than 10^-4 has been already achieved. The resolution of the measurement has reached to a few 10^-5. But it is known by the beam studies that the field change less than 10^-4 may cause deterioration of the luminosity. The requirement on the stability of magnetic field will be stricter for future nano beam colliders. We have studied the effects of the following conditions on the magnetic field by using some KEKB magnets: changes of the magnetic field due to air or cooling water temperature, changes due to initialization conditions, field coupling between the adjacent magnets, effect of excitation of the adjacent magnet and behavior of the magnetic field under polarity change have been measured. These studies are not only useful for the existing KEKB but also important for future nano beam accelerators.

• K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto
  KEK, Ibaraki

Injection into the J-PARC main ring is implemented by 4 kickers and 2 pulsed septa at 3 GeV in a long straight section. To accommodate the injection beam of 54 pmm.mrad, both septa have large physical acceptance of 81 pmm.mrad. However, large aperture leads to large end fringe field interfereing the circulating beam and causing beam loss, which has been observed even at low beam intensity during the beam commissioning. To provide users a proton beam with high beam power, the injection beam intensity will increase greatly in future, which creates difficulties for the present injection system. To accommodate these high intensity beams with low beam loss, the injection system needs to be upgraded. Taking account the strong space charge effects, even larger physical is needed to reduce the localized beam loss, which creates severer end fringe leakage field. This paper will discuss the problems encountered in operating the present septa, and give an optimized design for the new septa.

• K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto
  KEK, Ibaraki

The J-PARC is a high intensity proton accelerator complex, which consists of a LINAC, a Rapid Cycling Synchrotron (RCS) and a Main Ring (MR). The MR injection system employs a high-field septum to deflect the incoming beam from the RCS, which has been used for the beam commissioning study with low beam intensity successfully. Relative large beam losses in the injection area have been observed, which is proportional to the injection beam intensity. In future, the beam intensity will increase about 100 times to realize high beam power (~MW) operation required from neutrino experiments. The beam loss at the injection region is expected increase greatly due to the space charge effects, which creates severe radiation problems. Since the present injection septum coil is organic insulated, which will be destroyed under such a severe irradiation quickly. To cope with this problem, a new high radiation resistant injection septum magnet is developed, which uses inorganic insulation material (Mineral Insulated Cable - MIC) to prevent the septum from radiation damage. This paper investigates different effects caused by the MIC and gives an optimization design.

• S. Igarashi, T. Oogoe, H. Someya, S. Yamada
  KEK, Ibaraki
• Y. Kuniyasu
  MELCO SC, Tsukuba
• S. Nakamura
  J-PARC, KEK & JAEA, Ibaraki-ken

Efforts have been made to reduce the magnetic field ripple of the bending, quadrupole and sextupole magnets of the J-PARC main ring using the trim coils of the magnets. The quadrupole magnet has 24 turn main coil and 11 turn trim coil per pole those can be considered as a primary winding and a secondary winding of a transformer. When the trim coil is shorted, the induced trim coil current cancels the field ripple. The field ripple of the quadrupole magnet was reduced by a factor of 6 by shorting trim coil. The trim coil current, however, deforms the acceleration field pattern if the coil is shorted all the time of the current pattern of flat bottom, acceleration, flat top and recovery. The MOSFET relay was used to short the coil and to reduce the field ripple during the flat bottom and flat top. The circuits were built for the quadrupole and sextupole magnets. The plan has been made to wind optimized trim coils for the bending magnets.

• S. Ushijima, H. Fujisawa, M. Ichikawa, Y. Iwashita, H. Tongu, M. Yamada
  Kyoto ICR, Uji, Kyoto

A compact neutron source using Li(p,n) or Be(p,n) reaction is proposed. The proton linac consists of ECR ion source, LEBT(Low Energy Beam Transport), RFQ linac and post accelerator. We assume that energy of the proton beam is 3MeV and its peak current is 40 mA operated at the repetition rate is 25Hz with the pulse width of 1ms. The beam from the ion source should be matched to the RFQ, where solenoid coils can handle the large current beam in this LEBT section. To reduce energy consumption in LEBT we're trying to design the Hybrid Electromagnet that consists of solenoid coils and permanent magnets. We use PANDIRA, TRACE-2D, and PBGUNS computer codes in order to simulate the magnetic field and the beam transport through LEBT. In this paper the design of this magnet and the result of its beam matching based on simulation will be presented.

• D.E. Kim, H.S. Han, Y.-G. Jung, K.R. Kim, H.-G. Lee, S.H. Nam, K.-H. Park, H.S. Suh
  PAL, Pohang, Kyungbuk

Pohang Light Source (PLS) is planning a major upgrade of the storage ring to meet the more demanding requirement from the synchrotron light users. The main features of the major upgrade are (1) increasing the electron beam energy from 2.5 GeV to 3.0 GeV for more higher energy X-ray photons, (2) decreasing the electron beam emittance from 1.89 nm to 5.8 nm to increase the photon brilliances, and (3) increasing the number of straight sections to install the insertion devices from 10 to 20 to meet the demand for insertion devices. in the upgraded PLS (PLS-II), there will be 24 combined function dipole magnets, 96 quadrupole magnets, and 144 sextupole magnets with some auxiliary magnets for electron beam injection. In this report, the physical design features, mechanical aspects of the magnet design are described.

• M.C.L. Buzio, P. Galbraith, S.S. Gilardoni, D. Giloteaux, G. Golluccio, C. Petrone, L. Walckiers
  CERN, Geneva
• A. Beaumont
  EBG MedAustron, Wr. Neustadt

At CERN, the control of five of the accelerators in the injector chain (i.e. PS, PS Booster, SPS, LEIR and AD) is based upon real-time magnetic measurements in a reference magnet. These systems ("B-trains") include usually a field marker to signal the achievement of a given field value, complemented by one or more pick-up coils to integrate flux changes. Recently, some issues have been raised concerning long-term reliability and possible performance improvements, in terms of both resolution and operational flexibility, for these systems. This paper reports the results of R&D activities launched to address these concerns, namely: the development of a novel ferrite gradient compensator to enable dynamic NMR field marking in the PS' combined function magnets; and the preliminary design of a standardized electronic acquisition and conditioning system aimed at enabling the requested improvements and at facilitating rapid maintenance interventions.

• M.C.L. Buzio, P. Arpaia, O. Dunkel, D. Giloteaux, G. Golluccio, A.M. Lombardi, F. Mateo Jimenez, S. Ramberger
  CERN, Geneva

Linac 4 is the injector upgrade currently under construction at CERN to improve luminosity and reliability for the whole accelerator chain. This machine will include about 120 high-gradient, 20 mm aperture Halbach-array permanent quadrupoles (PMQ) housed in the Drift Tube tanks, as well as about 80 electromagnetic quadrupoles (EMQ) with power cycles approx. 2 ms long. This paper is concerned with the magnetic measurements carried out at CERN on the first batch of PMQ, including several prototypes from different manufacturers, as well as those done on several spare Linac 2 EMQs reused in Linac 4's 3 MeV test stand. We first describe the test setup, focusing our attention on a prototype test bench based on technology developed for the LHC and able to carry out high-precision harmonic measurements in both continuously-rotating and stepping-coil mode (FAME*). Next we present the results obtained in terms of integral field strength and quality, with special emphasis on the analysis of very fast eddy current transients in the EMQs. Finally, we discuss the expected impact of these findings on the operation of the machine.

* N. R. Brooks et al, "Estimation Of Mechanical Vibration Of The LHC Fast Magnetic Measurement System", IEEE Transactions on Applied Superconductivity, vol. 18, No. 2 , 2008.

• M.C.L. Buzio, L. Bottura, O. Dunkel, L. Fiscarelli, J. Garcia Perez, G. Montenero, E. Todesco, L. Walckiers
  CERN, Geneva
• P. Arpaia
  U. Sannio, Benevento

One of the main requirements for the operation of the Large Hadron Collider at CERN is the correction of the dynamic multipole errors produced in the main magnets*. In particular, integrated sextupole errors in the main dipoles must be kept well below 0.1 units to ensure acceptable chromaticity. The feed-forward control of the LHC is based on the Field Description for the LHC (FiDel), a semi-empirical mathematical model capable of forecasting the magnet's behaviour in order to generate suitable corrector current waveforms. Measurement campaigns were recently undertaken to validate the model making use of a novel fast rotating-coil magnetic measurement system (FAME)**, able to detect superconductor decay and snapback transients with unprecedented accuracy and temporal resolution. In this paper we discuss the test setup and the results obtained both on the test bench and in the actual operation of the accelerator.

* P. Xydi et al, "A Demonstration Experiment For The Forecast Of Magnetic Field … ", EPAC 2008
** N. R. Brooks et al, "Estimation Of Mechanical Vibration Of …", IEEE TAS 2008

• F.-Y. Lin, C.-H. Chang, H.-H. Chen, J.C. Huang, M.-H. Huang, C.-S. Hwang, J.C. Jan, C.Y. Kuo, C.-S. Yang
  NSRRC, Hsinchu

Taiwan Photon Source (TPS) is a new third generation synchrotron storage ring with energy 3 GeV, which consists of 24 double-bend cells and its circumference is 518.4 m. Various accelerator lattice magnets which consist of 48 bending magnets, 240 quadrupoles and 168 multifunction sextupole magnets. All magnets pole profiles, edge shim and magnet end chamfer were designed in TOSCA and RADIA magnetic computation code. In order to verify the magnetic field quality of computation code, prototype magnets have been manufactured in this year. Two measurement systems, hall probe and rotating coils, were used for magnetic field mapping. This paper presents magnetic field mapping results of prototype magnets and compared with original magnetic circuit designs.

• J.C. Jan, C.-H. Chang, C.-S. Hwang, F.-Y. Lin
  NSRRC, Hsinchu

A magnet array of superconducting undulator SU15, with 130 poles and length 0.98 m, was constructed, and the field measurement and training are also performed at National Synchrotron Radiation Research Center (NSRRC). The NbTi wires were excited to 1.36 T @ 497 A after 28 times quench. A cryogenic Hall probe (length 2500 mm) was used to characterize the distribution of the magnetic field of magnet arrays in the 5.6-mm magnetic gap. The measurement region of the cryogenic Hall probe is greater than 1200 mm in the vertical dewar. The length shrinkage or expansion of the Hall probe depends on the thermal variation at both ends of the Hall probe. The length of the Hall probe will be evaluated in the field measurement region. The reproducibility of the measurement system was verified in the same experiment. A field shimming method involving a trim iron piece was used to correct for deviations of the magnetic field. This paper discusses the measurement accuracy in the cryogenic Hall probe system and presents results of the field shimming.

• C.Y. Kuo, C.-H. Chang, C.-S. Hwang
  NSRRC, Hsinchu

The free space between magnets of TPS storage ring is very tight, especially the space between quadrupole and sextupole magnets. The minimum space between the yoke of quadrupole and sextupole is about 150mm, and the space between coils is only 10mm. In this case, the significant magnetic field distortions could have an impact on the performance of machine. Two magnets simulation compare to the individual magnet were performed in TOSCA 3D model. The crosstalk effect shows that the sextupole component increases from 0.0004% to 0.04% in the quadrupole magnet and the quadrupole component increases from 0.0008% to 0.06% in the sextupole magnet. We discuss this crosstalk effect and how to decrease the effect with appropriate shielding.

• O. Delferrière, D. Boutin, A. Dael, A. Drouart, C. Mayri, J. Payet, J.-M. Rifflet
  CEA, Gif-sur-Yvette

S3 (Super Separator Spectrometer) [1] is a future device designed for experiments with the very high intensity heavy ion stable beams of SPIRAL2. It will be set-up at the exit of the linear accelerator LINAG at GANIL (Caen, France). It will include a target resistant to very high intensities, a first stage momentum achromat for primary beam suppression, a second stage mass spectrometer and a dedicated detection system. This mass spectrometer includes a set of four large aperture quadrupole triplets with embedded multipolar corrections. These magnets are a combination of three multipoles which could be realized with superconductor wound in flat racetrack coils. To enable the primary beam extraction one triplet has to be opened on one side, which requires a careful design of such a multipolar magnet. This paper describes the opened multipole geometry. It is adapted to large apertures as demonstrated by Opera 3d© magnetic simulations [2], including harmonic analysis and integral field homogeneity.

• E.S. Fischer, J. Macavei, A. Mierau, P. Schnizer, P.J. Spiller, St. Wilfert
  GSI, Darmstadt

The FAIR SIS100 accelerator at GSI Darmstadt will be equipped with fast ramped superconducting magnets. The high current Uranium beam modes with intermediate charge states, require ultra low vacuum pressures that can be achieved in long term operation only by cold beam pipes acting as a cryopump with stable temperatures well below 12 K for all operating cycles. The straightforward layout for reliable cooling usually conflicts with an efficient design for fast ramped superconducting accelerator magnets, strongly affected by AC loss generation, field distortion and mechanical stability problems. A full functional vacuum chamber design for SIS 100 has to take into account all these conflicting boundary conditions and trade off between mechanical stability, acceptable field distortions, AC loss minimisation and achievable temperatures. We discuss the cooling conditions for the dipoles and for the beam pipe including first test results. The analysis of the principal design aspects for the vacuum chamber with respect to the magnets operation parameters and an integral design approach are given. We present a technological feasible solution for model testing and full scale manufacturing.

• P. Schnizer, E.S. Fischer
  GSI, Darmstadt
• K. Aulenbacher, A. Jankowiak, U. Ludwig-Mertin
  IKP, Mainz
• C. Montag
  BNL, Upton, Long Island, New York

The Electron Nucleon Collider, proposed as an extension to the High Energy Storage Ring (HESR), is currently investigated and a first layout of the Interaction Region (IR) proposed. The limited size of the machine, the low beam energy and the Lorentz force vector pointing in the same direction for both beams make the IR design demanding. In this paper we present the parameters of the IR magnets, show the boundary conditions given by the beam dynamics and the experiments. We present first 2D designs for the electron and proton triplet magnets along with the separating dipole next to the collision point. Different methods to shield the beam in the spectrometer dipoles are investigated and presented.

• K. Sugita, E.S. Fischer, P. Schnizer
  GSI, Darmstadt
• P.G. Akishin
  JINR, Dubna, Moscow Region
• A. Mierau
  TEMF, TU Darmstadt, Darmstadt

Superconducting magnets are planned to be installed at the SIS100 accelerator ring for FAIR. The error compensation multipole corrector and the steerer are built as nested magnets to save longitudinal space in the ring, the chromaticity sextupole is a superferric magnet. We present the dynamic field quality of the SIS100 dipole and the vacuum chamber deterioration next to the 2D and 3D field quality of the multipole corrector and of the chromaticity corrector. The quality of the injection field of the SIS100 dipole is mainly dominated by eddy currents as soon as the field ramp starts. We show its AC losses concerning the hydraulic limits for cooling the magnet with forced two phase helium flow and conclude on the maximum chromaticity correction which is feasible for the foreseen magnet design. The results are discussed in respect of recent beam dynamic calculations on the ramp.

• S. Koch, T. Weiland
  TEMF, TU Darmstadt, Darmstadt

For the computation of the electromagnetic fields in large accelerator components, such as the superconducting dipole magnets to be installed in the heavy-ion synchrotron SIS100 at GSI, Darmstadt in context of the FAIR project, very large numerical models are required. By using parallelization techniques in combination with higher-order finite element approaches, full 3D solutions for the complicated geometry can be obtained in reasonable computational time. This is important, in particular, if repeated simulations need to be performed as in case of the determination of the sensitivity of the results to parametric changes, e.g. due to manufacturing tolerances. For that purpose, a parallelized 3D simulation tool is developed and applied to the prototype of the SIS100 dipole magnet. The results for the field quality during transient operation considering eddy currents in the conductive parts of the assembly are reported.

• T. Ogitsu, Y. Ajima, O. Araoka, Y. Fujii, N. Hastings, N. Higashi, M. IIda, N. Kimura, T. Kobayashi, Y. Makida, T. Nakadaira, T. Nakamoto, H. Ohhata, T. Okamura, K. Sakashita, K. Sasaki, M. Shibata, S. Suzuki, K. Tanaka, A. Terashima, T. Tomaru, A. Yamamoto
  KEK, Ibaraki
• A. Ichikawa
  Kyoto University, Kyoto
• H. Kakuno
  University of Tokyo, Tokyo

A superconducting magnet system for the J-PARC neutrino beam line was completed at the end of 2008. The system consists of 14 doublet cryostats; each contains 2 combined function magnets (SCFM). The SCFM uses two single layer left/right asymmetric coils that produce a dipole field of 2.6 T and quadrupole of 19 T/m. By 2008, the world first SCFM had been developed and tested successfully at KEK. The mass-production was started in 2005, and completed by summer 2008. The system installation and commissioning took place from Feb. 2008 to Mar. 2009. The beam operation was started in April 2009 and the first neutrino beam was generated on April 23rd. Since then beam operation and commissioning to increase beam intensity has been performed to achieve the near term milestone of 100 kW beam operation. The paper briefly summarizes the history of SCFM development and the system construction as an introduction to a discussion on beam operation experience of the SCFM system.

• M. Tawada, Y. Funakoshi, M. Iwasaki, H. Koiso, A. Morita, Y. Ohnishi, N. Ohuchi, K. Oide, K. Tsuchiya, Z.G. Zong
  KEK, Ibaraki

KEK is studying the design of the interaction region quadrupoles for the SuperKEKB of which the two beams of 4GeV/7GeV for LER/HER have a crossing angle of 83 mrad. For each beam, the final beam focusing system consisting of superconducting and permanent magnets is studied. The superconducting quadrupoles close to the interaction point for each beam are located in the compensation superconducting solenoid which cancels the solenoid field by the particle detector, Belle. These magnet parameters are optimized to obtain higher luminosity. In this paper, the design progress of final focusing system and magnets will be reported.

• K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, K. Nagayama, H. Okamura, T. Saito, H. Tamura, T. Yorita
  RCNP, Osaka

The RCNP accelerator cascade　consists of an injector Azimuthally Varying Field (AVF) cyclotron (K=140) and a ring cyclotron (K=400). It provides ultra-high-quality beams and moderately high-intensity beams for a wide range of research in nuclear physics, fundamental physics, applications, and interdisciplinary fields. The maximum energy of protons and heavy ions are 400 and 100 MeV/u, respectively. Experimental apparatuses are used like a pair spectrometer, a neutron time of flight facility with a 100 m long tunnel, a radioactive nuclei separator, a super-thermal ultra cold neutron (UCN) source, a white neutron source, and a RI production system for nuclear chemistry. Such ultra high resolution measurements as dE/E = 5x10-5 are routinely performed with the Grand-Raiden spectrometer by utilizing the dispersion matching technique. The UCN density was observed to be 15 UCN/cm³ at the experimental port at a beam power of 400 W. Some topics on the research are discussed in the talk.

• K. Hatanaka, M. Fukuda, J. Nakagawa, T. Saito, T. Yorita
  RCNP, Osaka
• T. Kawaguchi
  KT Science Ltd., Akashi
• K. Noda
  NIRS, Chiba-shi
• Y. Sakemi
  CYRIC, Sendai

A scanning magnet using high-temperature superconductor (HTS) wire was designed, fabricated, and tested for its suitability as beam scanner. After successful cooling tests, the magnet performance was studied using DC and AC currents. With DC current the magnet was successfully operated to generate designed field distributions and effective length. In AC mode, the magnet was operated at frequencies of 30-59 Hz and a temperature of 77 K as well as 10-20 Hz and 20K. The power loss dissipated in the coils was measured and compared with the model calculations. The observed loss per cycle was independent of the frequency and the scaling law of the excitation current was consistent with theoretical predictions for hysteretic losses in HTS wires.

• Z.G. Zong, N. Higashi, N. Ohuchi, M. Tawada, K. Tsuchiya
  KEK, Ibaraki

To supply the electrical power for the superconducting correctors in the interaction region of the proposed SuperKEKB, a kind of vapor cooled current leads is designed, which consists of 8 brass leads and can transport currents to 4 correctors simultaneously. The design current of the leads is about 50 A. The thermal and electrical behaviors have studied by the finite elements method and the cryogenic experiment is also planed to validate the performance. In this paper the design will be presented and the finite element model will be compared with the experimental data.

• T. Semba, T. Yamamoto
  Hitachi Ltd., Ibaraki-ken
• M. Abe
  Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
• Y. Iwasaki, T. Kaneyasu, S. Koda, Y. Takabayashi
  SAGA, Tosu

A 4T superconducting wiggler for 1.4GeV synchrotron radiation facility Saga Light Source (SAGA-LS) was developed and manufactured. The wiggler consists of one superconducting magnet as main-pole and two normal conducting magnets as side-poles. The superconducting coils are wound with NbTi wires on iron poles, which are directly cooled by a 2-stage GM cryocooler. The structure of the wiggler is made for compactness and cryogen-free operation. This paper describes its magnet design and manufacturing processes.

• A.D. Kovalenko, N.N. Agapov, V.D. Kekelidze, H.G. Khodzhibagiyan, I.N. Meshkov, V.A. Mikhaylov, V.A. Petrov, A.N. Sissakian, A. Sorin, G.V. Trubnikov
  JINR, Dubna, Moscow Region

NICA (Nuclotron-based Ion Collider fAcility) is the new accelerator complex currently under construction at JINR. The facility is aimed to provide collider experiments with heavy ions up to uranium (gold at the beginning stage) with a centre of mass energy up to 11 GeV/u and an average luminosity up to 10²⁷ cm^-2 s^-1. The collisions of polarized deuterons and protons are foreseen also. The accelerator complex includes two injector linacs, a superconducting booster synchrotron, a 6 GeV/u superconducting synchrotron (existing Nuclotron) and a collider consisting of two storage rings. Different modifications of superferric magnets based on a hollow composite NbTi cable operating at 4.5 K is proposed to be used for the NICA booster and collider rings. The twin-aperture collider dipole consists of two vertically assembled cold masses placed inside a common thermal shield and a common cryostat. The dipole good field aperture is fixed to 60 mm. The 2 T option, which design is very similar to the Nuclotron's one, was fixed as basis for the collider of 350 m long. R&D work on a curved 4 T Cosine(θ)-dipoles based on a hollow Nuclotron-type cable is proposed to be continued.

• S. Sanz, J. Calero, J.L. Gutiérrez, I. Moya, I. Podadera Aliseda, I. Rodríguez, L. Sanchez, F. Toral
  CIEMAT, Madrid
• P. Bosland, P. Bredy, G. Disset, N. Grouas, P. Hardy, V.M. Hennion, H. Jenhani, J. Migne, A. Mohamed, F. Orsini, J. Plouin, J. Relland
  CEA, Gif-sur-Yvette
• E.N. Zaplatin
  FZJ, Jülich

The IFMIF-EVEDA accelerator will handle a 9 MeV, 125 mA continuous wave (CW) deuteron beam which aims to validate the technology that will be used in the future IFMIF accelerator. The Linac design is based on superconducting Half Wave Resonators (HWR) operating at 4.4 K. Due to space charge associated to the high intensity beam, a strong superconducting focusing magnet package is necessary between cavities, with nested steerers and a Beam Position Monitor (BPM). First of all, this paper describes the preliminary study to choose between two quadrupoles or one solenoid as focusing device, both using NbTi wire. The solenoid shows more advantages, mainly associated to available space and reliability. Then, electromagnetic and mechanical design of the solenoid and the steerers are reported. Special care is taken in order to fulfil the fringe field limit at the cavity flange. An active shield configuration using an anti-solenoid has been adopted, avoiding remnant magnetization associated to passive shielding materials.

• F.F. Bertinelli, N. Catalan-Lasheras, P. Fessia, C. Garion, S.J. Mathot, A. Perin, C.E. Scheuerlein, S. Sgobba, H.H.J. Ten Kate, J.Ph. G. L. Tock, A.P. Verweij, G.P. Willering
  CERN, Geneva

Following the analysis of the September 2008 LHC incident, the assembly process and the quality assurance of the main 13 kA interconnection splices were improved, with new measurement and diagnostics methods introduced. During the 2008-2009 shutdown ~5% of these 10 000 splices were newly assembled with these improvements implemented, but essentially maintaining the original design. It is known today that a limiting factor towards 7 TeV operation is the normal conducting resistance of ~15% of the original main 13 kA interconnection splices, associated to the electrical continuity of the copper stabiliser. A "Splices Task Force" has been set up at CERN to evaluate the need for, develop and test design improvements and prepare the implementation of a consolidation campaign. Important issues of splice design, process choice, resources and time requirements are considered.

• M. Guinchard, K. Artoos, A.H.J. Gerardin, A.M. Kuzmin
  CERN, Geneva

Force transducers based on strain and capacitive gauges have been developed and used for monitoring the coil pre-stress during assembly and excitation of magnet models. This paper will summarize and compare the new techniques of mechanical measurements use at CERN for the New Inner Triplet Project. Furthermore the paper will give a comparison of the gauge performances (Creep effects, temperature effects, etc.) and will present the performances of the new data acquisition system developed at CERN to measure simultaneously the strain gauges, the capacitive gauges and other external parameters for the magnet.

• M. Koratzinos, F.F. Bertinelli, Z. Charifoulline, K. Dahlerup-Petersen, R. Denz, C.E. Scheuerlein, R. Schmidt, A.P. Siemko, A.P. Verweij
  CERN, Geneva
• R.H. Flora, H. Pfeffer, J. Strait
  Fermilab, Batavia

At each interconnection between LHC main magnets, a low-resistance solder joint must be made between superconducting cables to provide a continuous current path through the superconductor, and between the surrounding copper stabilizer to provide a current path in case the cable quenches. About 10,000 such joints exist in the LHC. An extensive campaign has been undertaken to characterize and map the resistances of both types of joints. All of the superconducting cable splices were measured using the enhanced protection system of the LHC superconducting circuits. No high-resistance superconductor splices were found above 3 nano-Ohms. Non-invasive measurements of the stabilizer joints were made at 300K in 5 of the 8 sectors, and at 80K in 3 sectors. More precise local measurements were made on suspect interconnects that were opened up, and poor joints were repaired. However, it is likely that additional imperfect stabilizer joints still exist in the LHC. A statistical analysis is used to place bounds on the remaining worst-case resistances. This sets limits on the maximum operating energy of the LHC, prior to a more extensive intervention.

• M. Solfaroli Camillocci, G. Arduini, B. Bellesia, J. Coupard, K. Dahlerup-Petersen, M. Koratzinos, M. Pojer, R. Schmidt, A.P. Siemko, H. Thiesen, A. Vergara-Fernández, M. Zanetti, M. Zerlauth
  CERN, Geneva

On 19th September 2008 the Large Hadron Collider (LHC) experienced a serious incident, caused by a bad electrical joint, which stopped beam operation just a few days after its beginning. During the following 14 months the damage was repaired, additional protection systems were installed and the measures to avoid a similar incident were taken (i.e. new layer of the Magnet Quench Protection System [nQPS], more efficient He release valves). As a consequence, a large number of powering tests had to be repeated or carried out for the first time. The re-commissioning of the already existing systems as well as the commissioning of the new ones has been carefully studied, then performed taking into account the history of each of the eight LHC sectors (warm-up, left at floating temperature,'). Moreover, a campaign of measurements of the bus-bar splice resistances has been carried out with the nQPS in order to spot out non conformities, thus assessing the risk of the LHC operation for the initial energy level. This paper discusses how the guidelines for the LHC 2009 re-commissioning were defined, providing a general principle to be used for the future re-commissioning.

• V.S. Kashikhin, N. Andreev, Y. Orlov, D.F. Orris, M.A. Tartaglia
  Fermilab, Batavia

Linear accelerators based on a superconducting technology need various superconducting magnets installed inside SCRF Cryomodules. At front end of Linear Accelerators installed relatively weak iron-dominated magnets. The focusing quadrupoles have integrated gradients in the range of 1 T - 4 T, and apertures 35 mm - 90 mm. At Fermilab were designed superconducting dipole correctors, and quadrupoles for various projects. In the paper presented these magnet designs, and test results of fabricated dipole corrector. There are also briefly discussed: magnetic and mechanical designs, quench protection, cooling, fabrication, and assembly inside cryomodule.

• V.S. Kashikhin, N. Andreev, V. Kashikhin, M.J. Lamm, A.V. Makarov, G.V. Romanov, K. Yonehara, M. Yu, A.V. Zlobin
  Fermilab, Batavia

Helical Solenoids (HS) were proposed for a muon beam ionization cooling. There are substantial up to 30 MeV/m energy losses during passing the muon beam through an absorber. The main issue of such system is the energy recovery. A conventional RF cavity has diameter which is too large to be placed inside HS. In the paper presented results of dielectric filled RF cavity design. The proposed cavity has helical configuration. Presented Helical Cooling Channel module design which includes: high pressure vessel, RF cavity, and superconducting HS. Discussed parameters of this module sub-systems and shown results of muon beam tracking in combined magnetic and electric 3D fields.

• A.V. Zlobin, V. Kashikhin, N.V. Mokhov, I. Novitski
  Fermilab, Batavia

Magnetic and mechanical designs of a superconducting quadrupole magnet with 120-mm aperture suitable for interaction regions of hadron colliders are presented. The magnet is based on a two-layer shell-type coil and a cold iron yoke. Special spacers made of a low-Z material are implemented in the coil midplanes to reduce the level of radiation heat deposition in the coil. The quadrupole mechanical structure is based on a thick aluminum collar supported by the iron yoke and stainless steel skin. Magnet parameters including maximum field gradient, field quality and temperature margin for NbTi or Nb₃Sn coils at the operating temperatures of 1.9 K and 4.5 K are reported. The level and distribution of radiation heat deposition in the coil and other magnet components are discussed.

• A.V. Zlobin, Y. Alexahin, V. Kashikhin, N.V. Mokhov
  Fermilab, Batavia

Conceptual designs of superconducting magnets (dipoles and quadrupoles) for a muon collider with a 1.5 TeV c.o.m. energy and an average luminosity of 10³⁴ cm^-2s^-1 are presented. All magnets are based on the Nb₃Sn superconductor and designed to provide an adequate operation field/field gradient in the aperture with the critical current margin required for reliable machine operation. In contrary to proton machines, the dipole magnets should have open midplanes, and, for some of them, the required good field quality region needs to have a vertical aspect ratio of 2:1 that imposes additional challenges for the magnet design. Magnet cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. The magnets and corresponding protective measures are designed to handle about 0.5 kW/m of dynamic heat loads from the muon beam decays. Magnet parameters are reported and compared with the requirements.

• A.V. Zlobin, E.Z. Barzi, V.S. Kashikhin, M.J. Lamm, V. Lombardo, M.L. Lopes, M. Yu
  Fermilab, Batavia
• G. Flanagan, R.P. Johnson, S.A. Kahn, M. Turenne
  Muons, Inc, Batavia

The Helical Cooling Channel (HCC) is a technique proposed for six-dimensional (6D) cooling of muon beams. The HCC for muon collider and some other applications is usually divided into several sections each with progressively stronger fields, smaller aperture, and shorter helix period to achieve the optimal muon cooling rate. Novel magnet design concepts based on simple coils arranged in a helical solenoid configuration have been developed to provide HCC magnet systems with the desired parameters. The level of magnetic field in the HCC high-field sections suggests using a hybrid coil structure with High Temperature Superconductors (HTS) in the innermost coil layers and Nb₃Sn superconductor in the outer coil layers. The development of the concepts and engineering designs of hybrid helical solenoids based on advanced superconductor technologies, with special emphasis on the use of HTS for high fields at low temperature is the key step towards a practical HCC. This paper describes the conceptual designs and parameters of a short HTS model of a hybrid helical solenoid, and discusses the structural materials choices, fabrication techniques, and first test results.

• S.A. Kahn, G. Flanagan, R.P. Johnson, M. Turenne
  Muons, Inc, Batavia
• F. Hunte, J. Schwartz
  North Carolina State University, Raleigh, North Carolina

YBCO superconductors originally developed for high temperature operation carry significant critical current even in the presence of extremely high magnetic field when operated at low temperature. The final stage of phase space cooling for a muon collider uses a solenoid magnet with fields approaching 50 T. As part of an R&D effort we present measurements of mechanical and electromechanical properties of the YBCO conductor. We examine the critical current verses magnet field angle at 4.2 K in a magnetic field. Quench properties of the conductor such as minimum quench energy threshold and quench propagation velocity will be measured to establish safe operational conductions for the muon cooling magnets. In this paper we describe a conceptual picture for a high field solenoid to be used for muon phase space cooling that incorporates these low temperature properties of YBCO.

• M. Turenne, R.P. Johnson
  Muons, Inc, Batavia
• F. Hunte, J. Schwartz
  North Carolina State University, Raleigh, North Carolina
• H. Song
  NHMFL, Tallahassee, Florida

High field accelerator magnets are needed for high energy physics applications. Superconducting materials able to reach these fields with low losses are required, and YBCO Roebel cable is being developed to address this issue. Characterization of commercially available Roebel cables for high field low temperature superconducting magnets is needed. YBCO Roebel cable with low AC losses is being developed and has limited commercial availability. Its behavior is not fully understood, however, especially in liquid helium and at high magnetic fields. YBCO Roebel cable will be acquired from a commercial vendor and characterized at cryogenic temperatures, in varying magnetic fields, and different strain configurations. A comprehensive behavior analysis will be performed, including operational and fatigue limits. Characterization of YBCO Roebel cable at low temperatures will be performed, including determination of the current flow path in steady-state and during quench using magneto-optical imaging, investigation of the effects of strand insulation, and examination of the mechanical and quench behavior at 4.2 K, 77 K, and varying magnetic fields.

• M. Turenne, R.P. Johnson, S.A. Kahn
  Muons, Inc, Batavia
• F. Hunte, J. Schwartz, L. Ye
  North Carolina State University, Raleigh, North Carolina

Magnet applications for high energy physics has long been an important driver for the development of superconducting technology. New high temperature superconductors (HTS), which have very high values of the upper critical field Hc2, show promise for magnets generating fields greater than 25 T, such as those required for muon cooling [1]. (Rare Earth)Ba2Cu3Oy (REBCO) coated conductor is an HTS material which is well suited to these needs; however it requires characterization in the low temperature (4.2 K), high magnetic field regime. We are proposing to measure electro-mechanical and magnetic properties, including angular field dependence of commercially available REBCO conductor. Here we present results of initial testing to characterize commercially available REBCO coated conductors at 77 K, including critical current and quench testing to calculate minimum the quench energy (MQE) and normal zone propagation velocity (NZPV).

• S. Caspi, D.W. Cheng, D.R. Dietderich, H. Felice, P. Ferracin, R.R. Hafalia, J.M. Joseph, J. Lizarazo, G.L. Sabbi, X. Wang
  LBNL, Berkeley, California
• G. Ambrosio, R. Bossert, A.V. Zlobin
  Fermilab, Batavia
• M. Anerella, A.K. Ghosh, J. Schmalzle, P. Wanderer
  BNL, Upton, Long Island, New York

Advanced superconductors such as Nb₃Sn are being considered for future magnet upgrades of the Large Hadron Collider (LHC) at CERN. The US LHC Accelerator Research Program (LARP) has developed a large bore (120mm) Nb₃Sn IR quadrupole (HQ) capable of reaching 15 T at its conductor and a gradients of 199T/m at 4.4K and 219T/m at 1.9K. HQ is addressing coil alignment and accelerator field quality in a shell-based mechanical structure. In this paper we summarize the fabrication, assembly and initial test results of the 1 m long two-layer magnet.

• M.A. Green, A.J. DeMello, D. Li, F. Trillaud, S.P. Virostek, M.S. Zisman
  LBNL, Berkeley, California
• X.L. Guo, S.Y. Li, H. Pan, L. Wang, H. Wu, S.X. Zheng
  ICST, Harbin

Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and the connections between leads, the cold mass support intercept, and the shields to the cooler first-stage. If the cooler 1st-stage temperature is too high, the refrigerator will not produce full 2nd stage cooling. If the 1st-stage temperature is too high, the temperature of the top of the HTS leads. As a result, more heat goes into the 4 K cold mass and the temperature margin of the top of the HTS leads is too small, which are in a magnetic field. The parameters that affect the magnet cooling are compared for the MICE coupling magnet and the spectrometer magnet.

• S.P. Virostek, M.A. Green, F. Trillaud, M.S. Zisman
  LBNL, Berkeley, California

The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory (RAL) in the UK, will demonstrate ionization cooling in a section of a realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3 meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section that matches the solenoid uniform field into the MICE cooling channel. The cold mass, radiation shield and leads are kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids has been completed. The key features of the spectrometer solenoid magnets are presented along with the details of a finite element model used to predict the thermal performance of the magnets.

• S. Crispel, M. Bonneton
  Air Liquide, Division Techniques Avancées, Sassenage
• M.F.D. Simon
  F4E, Barcelona
• J. Teah
  STFC/RAL/ISIS, Chilton, Didcot, Oxon
• R. Thiering
  ANSTO, Menai, New South Wales

Thanks to its experience in past projects in the field of neutron sources, Air Liquide DTA was involved in recent years in two major projects : a new Cold Neutron Source (OPAL) at ANSTO, Australia and a Spallation Neutron Source at ISIS, United Kingdom. The OPAL CNS is a liquid deuterium moderated source operating with a cold box with a refrigeration capacity of 5 kW at 25K designed and manufactured by Air Liquide DTA. ISIS Target Station 2 is a liquid hydrogen and solid methane moderated source for which Air Liquide DTA provided two Helium cold boxes (about 600W) operating at 20K derived from the standard Helial product, one customised cryogenic hydrogen loop, and very specific remote dismountable cryogenic transfer lines. These two cryogenic systems were fully commissioned on Air Liquide DTA dedicated test area before delivery to the customers. The purpose of this paper is to give a compared overview of the design and testing of the proposed cryogenic systems for these two projects.

• G. Mazzitelli, R. Bedogni, B. Buonomo, M. De Giorgi, A. Esposito, L. Quintieri
  INFN/LNF, Frascati (Roma)
• P. Valente
  INFN-Roma, Roma

A neutron source, based on photo-neutron production, has been designed and is under construction to upgrade the electron/positron/photon DAΦNE Beam Test Facility (BTF). We present the feasibility study, the solution chosen and the optimization done in order to maximize the neutron/photon yield as well as the comparison between different simulation codes (FLUKA/GEANT4/MCNPX). The first experimental test is foreseen in March 2010.

• K. Okabe
  University of Fukui, Faculty of Engineering, Fukui
• Y. Ishi, Y. Mori, T. Uesugi
  KURRI, Osaka

As for BNCT (boron neutron capture therapy) medical applications, an accelerator-based intense thermal or epithermal neutron source has been strongly requested recently. A scaling type of FFAG accelerator with ERIT (energy/emittance recovery internal target) scheme has been developed for this purpose. In this scheme, the beam emittance degradation caused by the neutron production target are cured by ionization cooling method. In this presentation, recent beam study of ionization cooling and neutron production will be described.

• S. Ishimoto, S. Suzuki
  KEK, Ibaraki
• M.A. Green
  LBNL, Berkeley, California
• Y. Kuno, M.Y. Yoshida
  Osaka University, Osaka
• W. Lau
  OXFORDphysics, Oxford, Oxon

Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with ~2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

• S.I. Meigo, M. Futakawa, M. Ohi, S. Shinichi
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• H. Fujimori
  KEK/JAEA, Ibaraki-Ken

In J-PARC, Materials and Life Science experimental Facility (MLF) is aimed at promoting experiments using the world highest intensity pulsed neutron and muon beams which are produced at a thick mercury target and a thin carbon graphite target by 3-GeV proton beams, respectively. The first beam was achieved at the target without significant beam loss in May 2008. It is succeeded stable operation with beam power of larger than 300 kW. After beam irradiation, the residual dose of radiation on the beam transport line is remarkably small where the highest dose is 20 microSv/h. In order to confirm stable operation of the facility, especially for the wellness of the target, it is important to obtain the beam profile at the target. We developed new technique by using imaging plate which is attached on the target vessel by remote handling technique via master slave manipulators. It is found that the beam profile shows good agreement with the calculation. It is also found that the beam scattering effect on the muon production target shows good agreement with the simulation calculation.

• M. Yamada, M. Ichikawa, Y. Iwashita, T. Kanaya, H. Tongu
  Kyoto ICR, Uji, Kyoto
• K.H. Andersen, P.W. Geltenbort, B. Guerard, G. Manzin
  ILL, Grenoble
• M. Bleuel
  RID, Delft
• J.M. Carpenter, L. Jyotsana
  ANL, Argonne
• M. Hino, M. Kitaguchi
  KURRI, Osaka
• K. Hirota
  RIKEN, Wako, Saitama
• S.J. Kennedy
  ANSTO, Menai
• K. Mishima, H.M. Shimizu, N.L. Yamada
  KEK, Ibaraki

We have developed a motorized magnetic lens for focusing of pulsed white neutron beams. The lens is composed of two concentric permanent magnet arrays, in sextupole geometry, with bore of 15 mm and magnet length of 66 mm. The inner magnet array is stationary, while the outer array is rotated (the frequency of the modulation of magnetic field inside the bore ν ≤ 25Hz), providing a sextupole magnetic field gradient range of 1.5x10⁴T/m² ≤ g' ≤ 5.9x10⁴T/m². By synchronization of a pulsed neutron beam with the sinusoidal modulation of the magnetic field in the lens, the beam is focused, without significant chromatic aberration, over a wide neutron wavelength band. We have constructed a focusing-SANS (Small Angle Neutron Scattering) test bed on the PF2-VCN (Very Cold Neutron) beam line at the Institut Laue-Langevin in Grenoble. The beam image size matched the source size (≈ 3mm) over of wavelength range of 30Å ≤ λ ≤ 48Å with focal length of ~ 2.3 m. Further, we have demonstrated the performance of this device for high resolution time-of-flight (tof) SANS for a selection of polymeric & biological samples, in a compact geometry of just 5 m.

• G.N. Kim
  Kyungpook National University, Daegu
• M.-H. Cho, I.S. Ko, W. Namkung
  POSTECH, Pohang, Kyungbuk
• H.-S. Kang
  PAL, Pohang, Kyungbuk
• K.S. Kim, M.W. Lee
  CHEP, Daegu

We report the activities by using the pulsed neutron facility which consists of an electron linear accelerator, a water-cooled Ta target, and a 12-m time-of-flight path. It can be possible to measure the neutron total cross-sections in the neutron energy range from 0.01 eV to few hundreds eV by using the neutron time-of-flight method. A 6LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 12.1 m. The background level was determined by using notch-filters of Co, In, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements of several samples (Dy, Nb) are in general agreement with the evaluated data in ENDF/B-VII. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones. We also report the isomeric yield ratios for isomeric pairs produced from photonuclear reactions by using the bremsstrahlung photons from the 70-MeV electron linac.

• P.A.E. Elkiaer, A. Jensen, C. Nielsen, C. Soerensen
  Danfysik A/S, Jyllinge

Danfysik A/S has developed a novel approach in constructing a low voltage, very high current and highly stable magnet power supply using parallel SCR converter stages. The design is well suited for driving superconducting magnets in a two quadrant operation. A ±10V 18kA power supply has been built to EPFL Lausanne with four parallel converters showing excellent performances and a very low installation time. One of the major difficulties in paralleling SCR converters is the current sharing between the individual converters, which becomes even harder at low voltages. The novel design, which will be presented here, assures current sharing within a few percent in the whole working area. The power supply has been developed having the following highlights in mind: High accuracy and stability (50ppm.), Good current sharing between parallel coupled converters without band width degradation, Very high current, One or two quadrant operation and Computer controlled. This paper describes the power converter topology ensuring the excellent current sharing.

• S. Grawunder, F. Schoelz, B. Spaniol
  W.C. Heraeus GmbH, Materials Technology Dept., Hanau
• R. Grill, W. Simader
  Plansee Metall GmbH, Reutte
• M. Heilmaier, D. Janda
  TU Darmstadt, Darmstadt
• W. Singer, X. Singer
  DESY, Hamburg

The RRR value of high pure Nb is showing strong relations to the individual production steps. Mainly the different kind of internal stresses caused by the several production steps are resulting in the variation of the RRR value. This work shows the RRR values along the complete production chain from the molten Ingot till to the finished cavity. The influence of the RRR value caused by stresses and the release of that stresses by vacuum annealing is shown.

• H. Umezawa, K. Takeuchi
  Tokyo Denkai Co., Ltd., Tokyo
• F. Furuta, T. Konomi, K. Saito
  KEK, Ibaraki
• K. Nishimura
  TKX Corporation, Osaka

KEK and Tokyo Denkai have developed new niobium ingot slicing technique. 150 pieces of the large grain niobium discs can be sliced in two days by using of this technique. Tokyo Denkai installed the slicing machine in December 2009. During the development of the slicing technique, we found that crystal growth mechanism in Electron Beam Melting. It gave us the suggestion to make a single crystal niobium ingot. This paper describes the production process of low cost and short production time niobium discs and single crystal niobium ingot development.

• J. Yang, T. Hu, X. Hu, D. Li, P. Tan, T. Yu
  HUST, Wuhan

High voltage electron accelerators are currently utilized in various industrial applications for Crosslinking Compounds, Sterilization, Polymerization, and vulcanization etc. The conceptual design of a high voltage electron accelerator for radiation technologies is considered in the paper. The key components of the electron accelerator are introduced and analyzed. Relevant physical parameters of the accelerator are then obtained. In order to verify the rationality of the design, beam optical paths are calculated by TRANSPORT program. The beam envelopes show that the physical design of this system can meet the requirement of engineering.

• F. Butin
  CERN, Geneva

The role of "Experimental Area Manager" supported by a well organized, charismatic and motivated team is absolutely essential for managing the huge effort needed for a multi-cultural, multi-disciplinary installation of cathedral-size underground caverns housing a billion dollar physics experiment. Between the years 2002 and 2008, we supervised and coordinated the ATLAS work site at LHC, from the end of the civil engineering to the first circulating beams, culminating with 240 workers on the site, 24 hours a day, 7 days a week, with activities taking place simultaneously on the surface, in the 60 m shafts and in the 100 m underground experimental cavern. We depict the activities preparation scheme (including tasks ranging from the installation of 280 ton cranes to super-delicate silicon detectors), the work-site organization method, the safety management that was a top priority throughout the whole project, and the open-communication strategy that required maintaining permanent public visits. The accumulation of experience enables us to summarize the critical success factors for a timely and successful completion of such a vast and complex project.

• L.R. Williams, F. Caspers, J.M. Dalin, J.Ph. G. L. Tock
  CERN, Geneva
• V. Haemmerle, C. Sauerwein, I. Tiseanu
  RAYSCAN, Meersburg

For the inspection of certain critical elements of the LHC machine a mobile computed tomography system has been developed and built. This instrument has to satisfy stringent space, volume and weight requirements in order to be usable and transportable to any interconnection location in the LHC tunnel. Particular regions of interest in the interconnection zones between adjacent magnets are the plug in modules (PIM), the soldered splices in the superconducting bus-bars and the interior of the quench diode container. This system permits detailed inspection of these regions without needing to break the cryo vacuum. Limited access for the x-ray tube and the detector required the development of a special type of partial tomography, together with suitable reconstruction techniques for 3 D volume generation from radiographic projections. We present the layout of the complete machine and the limited angle tomography as well as a number of radiographic and tomographic inspection results.