07 Accelerator Technology Main Systems

T09 Room-Temperature Magnets

Paper Title Page
WEPC138 Transient Electromagnetic Analysis and Thermal Design on the Magnet of 3-GeV Synchrotron 2332
 
  • M. Abe, S. Tounos
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  • T. Adachi
    KEK, Ibaraki
  • Y. Chida
    Hitachi Ltd., Ibaraki-ken
  • K. Nakamura, T. Watanabe
    Hitachi. Ltd., Hitachi Works, Hitachi-shi
  • T. Takayanagi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • N. Tani
    JAEA/LINAC, Ibaraki-ken
 
  J-PARC 3GeV synchrotron is operated at 25Hz alternatively, which can generate eddy currents and heat. They can disturb continuous operations. We prepared a design technique to analyze them and manage the temperature rises of the magnets. Eddy current and hysteresis heat generations were calculated with 3D models then temperature rises were evaluated with natural convection cooling from surfaces. The technique was applied on the dipole, quadrupole and bump magnets. Slits on intense eddy current position can decrease the heat generation, however deep slits can disturb magnetic field distribution. Their depth and positions were optimized for the temperature rise reduction. So far, the synchrotron operation is fair with reasonable temperature rises.  
WEPC139 Recent Experience in the Fabrication and Brazing of Ceramic Beam Tubes for Kicker Magnets at FNAL 2335
 
  • C. R. Ader, C. C. Jensen, R. E. Reilly, D. Snee, J. H. Wilson
    Fermilab, Batavia, Illinois
 
  Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil (titanium/inconel) alloy brazing material are stacked in the furnace and then brazed in the furnace at 1000°C. The ceramic specified is Alumina 99.8% Al2O3, a strong recrystalized high-alumina fabricated by slip casting. Recent experience at Fermilab with the fabrication and brazing of these tubes has brought to light numerous problems including tube breakage and cracking and also the difficulty of brazing the tube to produce a leak-tight joint. These problems may be due to the ceramic quality, voids in the ceramic, thinness of the wall, and micro-cracks in the ends which make it difficult to braze because it cannot fill tiny surface cracks which are caused by grain pullout during the cutting process. Solutions which are being investigated include lapping the ends of the tubes before brazing to eliminate the micro-cracks and also metallization of the tubes.  
WEPC141 Septa and Distributor Developments for H- Injection into the Booster from Linac4 2338
 
  • J. Borburgh, B. Balhan, T. Fowler, M. Hourican, W. J.M. Weterings
    CERN, Geneva
 
  The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented.  
WEPC142 Design of Pulsed Magnets for the Taiwan Photon Source 2341
 
  • C.-H. Chang, C. K. Chan, J.-R. Chen, C.-S. Fann, M.-H. Huang, C.-S. Hwang, F.-Y. Lin, Y.-H. Liu, C.-S. Yang
    NSRRC, Hsinchu
 
  A new Taiwan Photon source requires a high stability pulsed magnets for the top-up mode injection operation. We present a preliminary design of the pulsed magnets used for injection into the 3 GeV storage ring. A 0.6 m long kicker magnet prototype is fabricated for testing the field performance. The field testing results are described in this work. The septum magnet with a 0.4 mm thickness stainless steel vacuum chamber is real tested at 3 Hz operation. The field performance, the stray fields and the eddy current effect are presented in this paper.  
WEPC143 System for Local Magnetic Field Measurement System Based on a Coil with Three Square Millimeter 2344
 
  • J. F. Citadini, R. Basilio, M. Potye, G. Tosin
    LNLS, Campinas
 
  We present a magnetic field measurement system based on a rotating coil with 3mm2 active area and approximately 500 turns to measure local magnetic field. The structure of a coil is not so complex, simplifying the evaluation of its sources of errors. The steps used to build the coil are shown as well as the performance of the measurement system. The calibration of the coil was made against a magnetic field generated by a solenoid with very well determined geometry.  
WEPC144 Test Results of the AC Field Measurements of Fermilab Booster Corrector Magnets 2347
 
  • J. DiMarco, D. J. Harding, V. S. Kashikhin, S. Kotelnikov, M. J. Lamm, A. Makulski, R. Nehring, D. F. Orris, P. Schlabach, C. Sylvester, M. Tartaglia, J. C. Tompkins, G. Velev
    Fermilab, Batavia, Illinois
 
  Multi-element corrector magnets are being produced at Fermilab that will enable correction of orbits and tunes through the entire cycle of the Booster, not just at injection. The corrector package includes six different corrector elements - normal and skew orientations of dipole, quadrupole, and sextupole - each independently powered. The magnets have been tested during typical AC ramping cycles at 15Hz using a fixed coil system to measure the dynamic field strength and field quality. The fixed coil is comprised of an array of inductive pick-up coils around the perimeter of a cylinder which are sampled simultaneously at 100kHz with 24-bit ADC’s. The performance of the measurement system and a summary of the field results are presented and discussed.  
WEPC145 A Fast-sampling, Planar Array for Measuring the AC Field of Fermilab Pulsed Extraction Magnets 2350
 
  • J. DiMarco, C. Johnstone, O. Kiemschies, S. Kotelnikov, M. J. Lamm, A. Makulski, R. Nehring, D. F. Orris, A. D. Russell, M. Tartaglia, G. Velev, D. G.C. Walbridge, A. Yuan
    Fermilab, Batavia, Illinois
 
  A system employing a planar array of inductive pick-up coils has been developed for measurements of the rapidly changing dipole field in pulsed extraction magnets of the Fermilab MuCool project. The magnets are of C-type design, and have a peak field of 0.65 T during 8.33 millisecond half-sine pulse with 15 Hz repetition rate. The coils of the measurement system are fabricated on a single, 97.5 mm wide, 2-layer circuit board. The top layer of the circuit board has 15 unbucked coils distributed over its width. The bottom layer has a similar arrangement of coils, except each is bucked against the central winding to suppress the main dipole field and allow for more sensitive measurements of higher-order harmonics across the magnet mid-plane. The array of coils is simultaneously sampled at data rates of up to 100kHz with 10kHz bandwidth using 24-bit ADC’s. A detailed overview of the system and data analysis is presented, along with a characterization of results and system performance.  
WEPC146 Plasma Lens of the ITEP Heavy Ion Accelerator 2353
 
  • A. A. Drozdovsky, V. Abramenko, M. M. Basko, A. Golubev, D. D. Iosseliany, A. V. Kantsyrev, A. P. Kuznetsov, Yu. B. Novozhilov, O. V. Pronin, P. V. Sasorov, S. M. Savin, B. Y. Sharkov, V. V. Yanenko
    ITEP, Moscow
 
  At ITEP, on the bases of the TWAC-ITEP (Terawatt Accumulator) complex, a new facility is being built to conduct research at high energy densities in matter*. Application of a plasma lens to this area of research has a number of essential advantages in comparison with the traditional system based on quadruple lenses**. In accordance with the principal goals of this project, a pulse-power generator has been developed, with which a stable discharge current of up to 250 kA and duration of 4 μs has been achieved and which was used for experimental and theoretical investigation of the plasma lens performance. The plasma lens was installed into the exit channel of the TWAC accelerator complex, and its testing began by focusing of a C+6 beam with the ion energy of 200 MeV/a.u.m. As one of the first results, a minimum focal spot diameter of 350 μm FWHM has been measured at a target distance of 50 mm from the end of the discharge tube. The lens parameters were as follows: capacitance – 24 μF, charging voltage – 13 kV, discharge current – 220 kA, current half-wave – 4 μs, argon pressure – 3 mbar.

*Sharkov B. Yu. et al. Nucl. Instr. Meth. A464 (2001), p. 1.
** D. H.H. Hoffmann et al. Nucl. Instr. Methods Phys. Res., Sect. B 161-163, (2000), p. 9.

 
WEPC150 Fast Local Bump System for Helicity Switching at the Photon Factory 2356
 
  • K. Harada, Y. Kobayashi, T. Miyajima, S. Nagahashi, T. Obina
    KEK, Ibaraki
  • S. Matsuba
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima
 
  Two APPLE-II type variably polarizing undulators will be installed at the south straight section of the PF (Photon Factory) ring. The 10Hz fast orbit switching in these undulators will be conducted for the helicity switching. The required angular difference of the orbits in two undulators is 0.3mrad. The five identical bump magnets and AC power supplies are manufactured to make 10Hz time varying local bumps. In order to achieve the local bump and prevent the fluctuation of the beam orbit with the effects of the insertion devices and magnetic errors, the feed forward correction with the bump magnets and the feedback correction with the fast steering magnets are required. In this presentation, the measurement results of the magnetic field and the frequency response, the configuration of the control system, and the simulation results to achieve the local bumps are shown.  
WEPC151 Magnetic Field Design and Calculation for the FLNR U400R Cyclotron 2359
 
  • I. A. Ivanenko, J. Franko, B. Gikal, G. Gulbekyan, N. Yu. Kazarinov
    JINR, Dubna, Moscow Region
  • V. P. Kukhtin, E. A. Lamzin, S. E. Sytchevsky
    NIIEFA, St. Petersburg
 
  Presently FLNR reconstructs the U400 cyclotron. The new, U400R cyclotron is intended to accelerate the ion beams with A/Z from 4 to 12 up to the energy 0.78 – 27 MeV/nucleon. The wide range of the magnetic field levels from 0.8T till 1.8T allows to make a smooth variation of the beam energy over the range ±60% from nominal. For optimization of the magnetic field the 14 pairs of radial correcting coils are used. The numerical formation of the magnetic field is carried out. At the present work the main problems and solutions of the magnetic field design are described.  
WEPC152 Magnet Block Optimization of the APPLE-II Elliptically Polarized Undulator 2362
 
  • T. Wang, Q. K. Jia
    USTC/NSRL, Hefei, Anhui
 
  The uniform field region of elliptically polarized undulator (EPU) of APPLE-II type is very short especially in the horizonta axis. The magnet block arrangements with a approximately parabolic pole face or of APPLE-II undulator can enlarge the horizontal field roll-off and shorten the vertical field roll-off. We studied the dfferent shapes to expect a optimizaed horizotal and vertical field roll-off.  
WEPC153 Dipole Magnet for Use of RHIC EBIS HEBT Line 2365
 
  • T. Kanesue
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
  • M. Okamura, D. Raparia, J. Ritter
    BNL, Upton, Long Island, New York
 
  We present the design optimization of a dipole magnet for use of RHIC EBIS HEBT line. This magnet provides a total bending angle of 145 degrees by two identical magnets and it is used to guide H+ to Au32+ beam with energy of 2 MeV/amu. Magnetic field is required to change within 1 second corresponding to the ion species, so magnet body has the laminated structure to suppress eddy current. Effective length and field quality within a radius of 5 cm was optimized separately. Effective length was optimized by adjusting end shape not to change the beam orbit between low and high field operation more than 1 mm from intended beam orbit after bending. Then field quality was optimized by changing the shim position and additional bump. After modification, all multipole coefficients along the beam trajectory were reduced to within 10x10-4.  
WEPC154 Design and Fabrication of Multipole Corrector Magnet 2368
 
  • F.-Y. Lin, C.-H. Chang, H.-H. Chen, C.-S. Hwang, C. Y. Kuo
    NSRRC, Hsinchu
 
  The Taiwan Light Source (TLS) had started to operate in top-up mode injection since October 2005. Meanwhile, the Elliptically Polarized Undulator (EPU5.6) was operated very well in the decay mode operation. However, the partial beam loss had occurred when the top-up injection was executed at magnet gap and magnet array phase are fixed at the minimum gap and π(vertical polarization mode), respectively. In order to solve the partial beam loss, we design a new multipole corrector magnet to be installed in the downstream of the EPU5.6 to compensate for the multipole field error. This multipole magnet can provide the normal and skew components of the dipole, quadrupole, sextupole, octople, and dodecapole field components. Changeable multipole field components mechanism has been designed by using a special electric circuit. In addition, the measurement systems of Hall probe and stretch wire are used to measure the field quality of the multipole corrector magnet. This report will discuss the magnet circuit design, mechanical design, the switching mechanism of the multipole field components, and the field measurement results.  
WEPC155 Experimental Characterization of Permanent Magnet Harmonic Corrector Rings 2371
 
  • A. Madur, S. Marks, S. Prestemon, D. Schlueter
    LBNL, Berkeley, California
 
  A total of three permanent magnet chicane magnets have been installed at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The magnet design incorporates counter-rotating permanent magnet pairs with trim coils. The purpose is to provide a fixed angular separation between two successive elliptically polarizing undulator (EPU) photon fans and to correct steering perturbation resulting from EPU polarization state and gap changes. This paper presents a method for the determination of the permanent magnets parameters and setting relative orientations of the rotors by performing magnetic measurements with rotating coils. The measurement method will be developed and illustrated with experimental data from the measurement of a 16 cylinder permanent magnet harmonic corrector ring.  
WEPC156 Development and Adjustment of the EMMA Quadrupole Magnets 2374
 
  • N. Marks, B. J.A. Shepherd
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • M. J. Crawley, F. T.D. Goldie, B. Leigh
    Tesla Engineering Limited, West-Sussex
 
  The non-scaling FFAG EMMA, now under construction at STFC’s Daresbury Laboratory, requires 84 quadrupoles. Because of the unusual nature of these magnets*, prototypes for the F and the D type quadrupoles were required. These magnets were ordered from and constructed and measured by Tesla Engineering. Subsequently, design changes have been made and modifications to the prototypes carried out. The paper will give engineering details of these prototypes, of the measurement results obtained using a rotating coil magnetometer and subsequent adjustments to clamp plates and pole profiles needed to obtain optimum three dimensional gradient quality. As a result of these developments, the construction of the magnets for the complete ring is now underway.

*B. J.A. Shepherd & N. Marks, “Quadrupole Magnets For The 20MeV FFAG, ‘EMMA’”, PAC 2007 (MOPAN107).

 
WEPC157 A Hybrid Quadrupole Design for the RAL Front End Test Stand (FETS) 2377
 
  • D. C. Plostinar, M. A. Clarke-Gayther
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • P. Davis
    STFC/RAL, Chilton, Didcot, Oxon
  • S. J.S. Jago
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
 
  The Front End Test Stand project being constructed at Rutherford Appleton Laboratory (RAL) aims to deliver a high current (60 mA) H- chopped ion beam, at 3 MeV and 50 pps. The main components of FETS are the H- ion source, the Low Energy Beam Transport line (LEBT), the Radio Frequency Quadrupole (RFQ) and the Medium Energy Transport (MEBT) line with beam chopper. Space restrictions in the MEBT line place constraints on component length and drive the requirement to identify compact component configurations. A description is given of a novel compact hybrid quadrupole magnet, whose design is based on the concentric combination of a permanent magnet quadrupole (PMQ) and a laminar conductor electromagnetic quadrupole (EMQ). Simulations of magnetic field distribution in 2 and 3D are presented, and possible applications and further developments are discussed.  
WEPC159 Compact Design of Race-track Microtron Magnets 2380
 
  • J. P. Rigla, Yu. A. Kubyshin
    UPC, Barcelona
  • S. Ferrer
    ALBA, Bellaterra
  • A. V. Poseryaev, V. I. Shvedunov
    MSU, Moscow
 
  A novel design of the end magnets for race-track microtrons (RTMs) is proposed. It consists of four-poles with the REPM material being used as a source of the magnetic field. For a proper choice of parameters of such magnetic system it can provide both the closure of the first orbit after beam reflection and required focusing properties. It is shown that such end magnet can be made quite compact thus allowing to build miniature RTMs. The procedure of design of the four-pole magnetic system and its optimization using the ANSYS code is described in detail.  
WEPC160 Eddy-current Effect on Field Multipoles Arising in Dipole Magnets with Elliptic and Rectangular Beam Pipe 2383
 
  • E. Perevedentsev, A. L. Romanov
    BINP SB RAS, Novosibirsk
 
  We present an analytical evaluation of the field-distortion effect from eddy currents induced by variation of magnetic field of dipole magnets with elliptic or rectangular beam pipe of finite conductivity. The pipe sizes and aspect are arbitrary except that for practical reasons we assume the pipe wall thickness is small as compared to the skin depth. Handy formulas are presented for the field multipoles arising from non-round shape of the beam pipe.  
WEPC161 Some Remarks about Characterization of Magnetic Blocks with Helmholtz Coil 2386
 
  • G. Tosin, R. A. Pimenta
    LNLS, Campinas
 
  The use of Helmholtz coils for magnetic block characterization is a widespread technique because of its small sensitivity to block positioning errors and high precision. In this paper we present some calculations related to the influence of block positioning for the cases where the Helmholtz condition is not exactly satisfied. Also the comparison between a model based on point dipolar magnetic moment and magnetized blocks with real dimensions is analyzed, as well as the corrections associated to the effect of self-demagnetization of the blocks.  
WEPC163 Modification of a Spare Septum Magnet for SNS Ring Injection Dump Beam Line 2389
 
  • J. G. Wang
    ORNL, Oak Ridge, Tennessee
 
  The SNS ring injection dump septum magnet has been suffering the heaviest beam losses since the ring commissioning. These beam losses are caused by a number of design and operation problems such as incorrect location of one chicane dipole, incorrect chicane dipole setting, and inadequate aperture of the injection dump septum. We have modified a spare septum by increasing its vertical and horizontal aperture and by adding specially designed z-bumps for one of the waste beams. This paper reports the detailed modification results, including 3D particle trajectory calculations and experimental measurements.  
WEPC164 Development of Modulating Permanent Magnet Sextupole Lens for Focusing of Cold Neutrons 2392
 
  • M. Yamada, M. Ichikawa, Y. Iwashita, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • T. Ino, S. Muto, H. M. Shimizu
    KEK, Ibaraki
 
  A modulating permanent magnet sextupole lens that can focus pulsed cold neutrons is under development. It is based on the extended Halbach configuration to generate stronger magnetic field. In order to adjust the strength, the magnet is divided into two co-axial nested rings, where the inner ring is fixed and the outer ring can be rotated. Synchronizing the period of the modulation with that of pulsed neutron beam suppress the chromatic aberration. We have fabricated a half-scale model and studied the strength, the torque and the temperature rise caused by eddy current. Now we are developing the full-scale model improving such problems. These two scale models of magnet are described.  
WEPC165 Magnetic Measurements of the SSRF Storage Ring Magnets 2395
 
  • J. D. Zhang, Q. G. Zhou
    SINAP, Shanghai
 
  The SSRF storage ring comprises a total of 460 magnets which has four types and eight different effective magnetic lengths. The magnetic measurements of all the production magnets including 40 bending magnets with a maximum field of 1.2726 T, 200 quadrupoles divided in Three families with a maximum gradient of 20 T/m, 140 sextupoles with a maximum second order differential of 460 T/m, and 80 correctors with a maximum kick capability of 1.2 mrad. For the dipoles a long coil system has been used to measure the magnetic field while for the quadrupoles and sextupoles a rotating coil system has been used to determine the magnitude of the high order multipoles. In this paper the analysis of these data is discussed and results for measured magnets are presented.  
WEPP170 A 15-T Pulsed Solenoid for a High-power Target Experiment 2889
 
  • H. G. Kirk
    BNL, Upton, Long Island, New York
  • J. R.J. Bennett
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • I. Efthymiopoulos, A. Fabich, F. Haug, H. Pereira
    CERN, Geneva
  • K. T. McDonald
    PU, Princeton, New Jersey
  • P. H. Titus
    MIT/PSFC, Cambridge, Massachusetts
 
  The MERIT experiment, which ran at CERN in 2007, is a proof-of-principle test for a target system that converts a 4-MW proton beam into a high-intensity muon beam for either a neutrino factory complex or a muon collider. The target system is based on a free mercury jet that intercepts an intense proton beam inside a 15-T solenoidal magnetic field. Here, we describe the design and performance of the 15-T, liquid-nitrogen-precooled, copper solenoid magnet.