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quadrupole

     
Paper Title Other Keywords Page
MOXMA01 Present Status of J-PARC linac, synchrotron, klystron, rfq 1
 
  • F. Naito
    KEK, Ibaraki
  Japan Proton Accelerator Research Complex (J-PARC) is the high-intensity proton accelerator aiming to realize 1 MW class of the beam power. It is the joint project between High Energy Accelerator Research Organization (KEK) and Japan Atomic Energy Agency (JAEA). J-PARC consists of a 400MeV linac, a 3GeV Rapid Cycle Synchrotron (RCS) and a 50 GeV Main Ring (MR). At the present stage, the beam energy from the linac is 181 MeV and it will be extended to 400 MeV at the near future. Most components of the linac have been installed in the beam line, and the remaining preparation for the beam commissioning is underway. Since the beam commissioning of the linac will start in December 2006, the first result of the linac beam test will be reported at the conference. The beam commissioning for the RCS is scheduled in the middle of 2007. Finally that for the 50GeV synchrotron will be started at the beginning of 2009.  
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TUXMA01 LHC Status dipole, cryogenics, injection, insertion 46
 
  • L. R. Evans
    CERN, Geneva
  The installation of the Large Hadron Collider at CERN is now approaching completion. Almost 1100 of the 1232 main bending magnets are installed and the whole ring will be installed by the end of March 2007. Emphasis is now moving from installation to commissioning, with the cool down of the first of the 8 sectors to liquid helium temperature well underway. In the other sectors, interconnect work is proceeding at a satisfactory pace and will be finished by the end of August. It is foreseen to inject the first beam into the LHC in November with the objective of having first collisions at the injection energy (450 GeV/c) in order to debug the machine and detectors before stopping for the annual winter shutdown. During this time, the detector installation will be finished and the machine will be pushed to full current ready for the first physics run at 7 TeV per beam in 2008.  
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TUC2MA02 Design of the Transfer Lin·10-2 for the CTF-3 at CERN dipole, sextupole, controls, lattice 71
 
  • A. Sharma, A. D. Ghodke, A. Rahim, G. Singh
    RRCAT, Indore (M. P.)
  The design of the Transfer Lin·10-2 (TL-2), which will transfer an electron beam from the Combiner Ring (CR) to CLEX area (CLIC experimental area) of CTF-3 at CERN, is presented in this paper. This line will be used to control the bunch length and Twiss parameters at the entrance to the CLEX area. The line will have a wide tunability of R56 parameter, ranging from –0.35 to +0.35m. This has been designed considering the constraints imposed by the building geometry and the magnetic elements to be used. The design optimization of the line has been done up to second order for the entire R56 range, keeping T566 practically zero and emittance dilution below 10%.  
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TUZH103 Electron Cloud Experiments, Simulation and Cure electron, simulation, feedback, dipole 89
 
  • H. Fukuma
    KEK, Ibaraki
  A large number of electrons called electron clouds have been observed both in positron and hadron accelerators. Possible sources of the electron clouds are photoelectrons generated by synchrotron radiation, electrons produced by beam hitting vacuum components, electrons multiplied by beam induced multipacting, electrons created by ionization of residual gasses and so on. The electron clouds produce various effects such as pressure rise, heat load on a cold chamber wall, beam induced multipacting, betatron tune shifts, coupled bunch instability and beam size blow-up which often limit the performance of the accelerators. Many experimental and theoretical studies on the electron clouds have been carried out and their results have contributed to the improvement of performance of existing accelerators and design of future accelerators. This talk reviews experiments, simulations and cures of the electron cloud effects in positron and hadron accelerators.  
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TUPMA020 Beam Based Alignment and COD Correction for the Siam Photon Source photon, controls, alignment, betatron 130
 
  • S. Rugmai, S. Rugmai
    Suranaree University of Technology, Nakhon Ratchasima
  • P. Klysubun, C. Kwankasem, P. Sudmuang
    NSRC, Nakhon Ratchasima
  The first systematic Beam based Alignment (BBA) and COD correction attempt for the Siam Photon Source has been performed. Automated measurements were carried out using MATLAB OPC Toolbox, interfacing to the PLCs of the accelerator control system. Calculations of theoretical parameters were performed with Accelerator Toolbox via MATLAB interface. Since the Beam Position Monitors (BPMs) were not properly calibrated prior to installation beam based calibrations were carried out. Preliminary calibration factors for each BPM were obtained by normalizing BPM signals to modeled steering magnet responses. Measurements of offsets between BPM and quadrupole centers were performed by fitting for minima of orbit response to changes of quadrupole strengths. The resulting offsets were superimposed to the BPM readings in the PLC. COD correction was then performed.  
 
TUPMA060 A Hamiltonian for Wave Length Shifter and its Studies on INDUS-1 injection, electron, dynamic-aperture, betatron 199
 
  • A. A. Fakhri, G. Singh
    RRCAT, Indore (M. P.)
  The INDUS-1 is a 450 MeV synchrotron radiation source for the production of VUV radiation. In order to produce the radiation of shorter wavelengths(lc = 31 Ao), a superconducting wavelength shifter (WLS) with peak fieldof 3T is being considered for Indus-1. In this paper, L. Smith's Hamiltonian for Halbach's magnetic field model has been re-derived to estimate focussing component under the compensated electron beam trajectory transformation. Various linear compensation schemes are presented to minimize the linear effects of the WLS and its effects on machine operation are also theoretically studied.  
 
TUPMA084 Ions for LHC: Status of the Injector Chain ion, emittance, optics, injection 226
 
  • D. Manglunki, A. Beuret, J. Borburgh, C. Carli, M. Chanel, L. D. Dumas, T. Fowler, M. Gourber-Pace, S. Hancock, M. Hourican, J. M. Jowett, D. Kuchler, E. Mahner, M. Martini, S. Maury, S. Pasinelli, U. Raich, A. Rey, J.-P. Royer, R. Scrivens, L. Sermeus, G. Tranquille, J. L. Vallet, B. Vandorpe
    CERN, Geneva
  The LHC will, in addition to proton runs, be operated with Pb ions and provide collisions at energies of 5.5 TeV per nucleon pair, i.e. more than 1.1 PeV per event, to experiments. The transformation of CERN's ion injector complex (Linac3-LEIR-PS-SPS) to allow collision of ions in LHC in 2008 is well under way. The status of these modifications and the latest results of commissioning will be presented. The remaining challenges are reviewed.  
 
TUPMA105 Transverse Matching of the SNS Linac Based on Profile Measurements linac, emittance, beam-losses, proton 250
 
  • D.-O. Jeon, P. Chu
    ORNL, Oak Ridge, Tennessee
  For a high intensity linac such as the SNS linac, it matters to match to minimize the beam mismatch and potential beam loss. It was observed that matching was improved through the matching technique based on the beam profile measurements from wirescanners.

*SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.

 
 
WEPMA013 Analysis and Correction of the Measured COD in INDUS-2 closed-orbit, synchrotron, injection, betatron 351
 
  • R. Husain, A. D. Ghodke, G. Singh
    RRCAT, Indore (M. P.)
  In Indus-2 there are 56 button type beam position monitors (BPMs), 48 horizontal and 40 vertical steering magnets. The measured orbit has been fitted by effective quadrupole misalignments by using SVD of the response matrix generated between BPMs and the quadrupole misalignments in the model obtained by setting the magnet strengths as per the current set in the magnets. We present the different global and local orbit correction algorithms developed for minimizing and controlling the orbit. The preliminary result for the orbit correction, at injection energy, in horizontal plane using best orbit correctors identified by doing SVD of the response matrix is presented. The results for the local four orbit bumps are also presented.  
 
WEPMA039 Effect of Magnetic Field Coupling On INDUS-2 Quadrupole Magnets simulation, coupling, dipole, multipole 378
 
  • G. Sinha, A. Kumar, A. Mishra, G. Singh
    RRCAT, Indore (M. P.)
  The distances between the magnets in the Indus-2, are small and as a result, the magnetic field of one magnet may affect the fields of the adjacent magnets. Therefore, it is important to find out the effect of mutual coupling between magnets in the actual condition in the ring and the ways to overcome this problem. In this paper, we will discuss how the field quality of Quadrupole magnets (QPM) in the ring is affected when accompanied by various corrector dipole magnets (CDM)(vertical and horizontal) and sextupole magnets (SPM). Variation of integrated quadrupole strength in presence of CDM is measured at various field excitations and also by varying the distance between the magnets using a rotating coil. Experimental results are compared with the results obtained from 3D simulations. Possibilities of studying the interference effect by scanning the field by a Hall probe, is explored. Dependence of field interference on the distance between magnets, pole gap and the steel length are studied. Effects of the adjacent magnets on the higher order multipole of QPM are also examined.  
 
WEPMA045 Study of Space Charge Compensation In LEBT space-charge, simulation, proton, rfq 384
 
  • S. C.L. Srivastava, T. Basak, R. Pande, S. Roy, P. Singh, V. L.SR. sista
    BARC, Mumbai
  A 20 MeV, 30 mA CW proton accelerator is being built in BARC which consists of 50 keV ECR ion-source, LEBT, 3 MeV RFQ, MEBT and 20 MeV DTL. In designing low energy beam transport (LEBT) line, which matches the beam from ion-source to RFQ, the expansion of the proton beam is a severe problem. As the energy of the beam is only 50 keV, coulomb repulsion is enormous and for minimization of this repulsion, space charge compensation is done. In this process, a gas is introduced in the beam pipe, which gets ionized by the beam. The produced electrons are trapped in the beam potential and reduce the repulsive space charge forces. To simulate the beam dynamics part, a PIC code is written, which allows beam of different distributions like KV, Parabolic, and Waterbag. This is an electrostatic code, which can also take care of external magnetic fields. A Monte Carlo collision scheme is being implemented for the ionization of the background gas. In this paper, we are presenting the simulation of space charge compensation of the 30 mA proton beam at 50 keV.

e-mail: shashics@barc.gov.in

 
 
WEPMA058 Tune and Lifetime Studies at the Australian Synchrotron sextupole, kicker, synchrotron, injection 401
 
  • M. J. Spencer, M. J. Boland, R. T. Dowd, G. LeBlanc, Y. E. Tan
    ASP, Clayton, Victoria
  The 3GeV Australian Synchrotron will begin operation in March 2007. This paper outlines the tune and lifetime measurement systems. It also provides a summary of a number of studies completed using these systems. Three different tune measurement systems have been tested. Lifetime measurements made using the DCCT were used to optimise the strengths of the harmonic sextupoles and the location of the tunes. The vertical aperture was determined using scrapers. Beta-function measurements have been completed by shunting individual quadrupoles and noting the resultant tune changes. Chromaticity measurements have been made by observing the change in tune as the RF frequency is varied.  
 
WEPMA059 Commissioning of the Australian Synchrotron with Libera EBPPs and Matlab synchrotron, controls, lattice, storage-ring 404
 
  • Y. E. Tan, M. J. Boland, R. T. Dowd, G. LeBlanc, M. J. Spencer
    ASP, Clayton, Victoria
  The Australian Synchrotron (AS) is equipped with a full compliment of 98 BPMs attached to Libera Electron Beam Position Processors (EBPPs) that are capable of measuring turn-by-turn/first turn and averaged beam positions simultaneously. The BPM system coupled with Matlab applications has simplified the process of commissioning. This report will highlight how the various tools have been utilised and show the results of some studies.  
 
WEPMA085 Implementation and Experience of Energy Ramping for Indus-2 controls, power-supply, dipole, sextupole 443
 
  • R. K. Agrawal, A. Chauhan, P. Fatnani, R. Husain, K. Saifee, M. Seema, Y. M. Sheth, G. Singh
    RRCAT, Indore (M. P.)
  Beam energy ramping in Synchrotron Radiation Sources (SRS) requires synchronous increase in power supply currents attached to various magnets. This paper describes the implementation at various layers of control system architecture, experience of ramping beam energy from injection energy to 2 GeV. The total Ramping system hardware and software for both Magnet power supplies and RF cavity voltage are described with problems faced during the energy ramping. The implemented ramping system provides a tracking uncertainty less than 10μsec in time.  
 
THC2MA03 Design of L-band Superconducting Cavity for the Energy Recovery Linacs damping, dipole, linac, simulation 570
 
  • K. Umemori, T. Furuya, S. Sakanaka, T. Suwada, T. Takahashi
    KEK, Ibaraki
  • H. Sakai, K. Shinoe
    ISSP/SRL, Chiba
  • M. Sawamura
    JAEA/ERL, Ibaraki
  The ERL project in Japan has been started with the cooperation of?KEK, JAEA, ISSP and other SR institutes. For the ERL, superconducting cavities are key components to achieve high energy, high current and low-emittance electron beams. One challenging task, required for the cavity, is a strong damping of the higher-order-modes (HOMs), since they could cause the beam-breakup instabilities and the significant heat load on the cryomodule. We are proceeding with the cavity design, which is optimized for ERLs, with concentrating our attention on HOM damping. A large diameter beam-pipe with microwave absorber is adopted as HOM damping scheme. It can extract the HOM power effectively. We have also investigated optimization of the cavity shape for further suppression of the HOMs. In this report, our cavity design and its HOM characteristics are presented.  
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THPMA008 Field Measurement Results of the Quadrupole Magnets for ATF2 sextupole, extraction, power-supply, coupling 637
 
  • M. Masuzawa, Y. Suetsugu, R. Sugahara
    KEK, Ibaraki
  ATF2 will be built at KEK as a test facility for the final focus system for the ILC. The specifications for the final focus system require transverse focusing of the electron beam to be nearly 40 nm. The quadrupole magnets for the ATF2 beam line have been designed and manufactured. The diameter of the magnet bore is 32 mm and the length is 180 mm. The magnets have to meet strict specifications for the multipole components, especially the sextupole components, in order to achieve the required small beam size. Precision measurement is required not only for the multipole components but also for the magnetic center and median plane. Field measurement results of these small bore magnets will be reported.  
 
THPMA010 Structures of Quadrupole Magnet Core pick-up, controls, vacuum, magnet-design 640
 
  • N. Li
    SLAC, Menlo Park, California
  In general, there are two different quadrupole core designs: two pieces (up half and low half cores) and four pieces (four quarter halves). Both structures work on those quadrupole magnets in different accelerators around the world. There is no certain rule about which design is good for what machine, it is most likely defends on the engineer’s favor and the coil size. There is advantage and disadvantage for both structures. However, the disadvantage of four pieces design is rather visible. It is the goal of this paper to study those advantages and disadvantages of two types of core structure from manufacturer’s point of view and the perturbations of the magnet field.

* Iron Dominated Electromagnets

 
 
THPMA014 Mechanical Stability of Open-type Quadrupole Magnets for a 2.5 GeV SRS (Indus-2) magnet-design, multipole, vacuum, dipole 646
 
  • S. Konjeti, S. Das, M. G. Karmarkar, P. K. Kulshreshtha, K. Ruwali, K. Swarna
    RRCAT, Indore (M. P.)
  • M. K. Ghosh
    BHU, Varanasi
  The open type Quadrupole magnets (Max. gradient: 16 T/m) for 2.5 GeV Indus-2 are made in C-configuration in which both of outer vertical sections of the steel are removed to take out the emerging synchrotron beam lines, in the region immediately adjacent to main dipole magnets of the ring. This induces engineering complexity relating to mechanical stability that critically controls the deviations in magnetic centre and field quality. To meet the stringent field quality requirements, the mechanical structure, which is precisely holding the magnet poles, is designed for minimum deflection at maximum gradient. The magnet is simulated with coupled field Emag-structural analysis, using ANSYS. The measurement of magnetic centre shift in prototype magnet assemblies with maximum excitation current is within 15 microns. The magnetic measurement results show that the higher order multipoles are low and not changing with excitation current. The optimized open-type Quadrupole magnet design is implemented in series production of all 32 magnets. The mechanical assembly accuracies and stability of series magnets with excitation are discussed in this paper.  
 
THPMA020 Ideal Coil-Shape for Perfect Field in Superconducting Sextupole Magnets sextupole, dipole, vacuum, superconducting-magnet 658
 
  • P. R. Sarma
    DAE/VECC, Calcutta
  Coil dominated superconducting magnets have become essential components in high energy accelerators. Such magnets need to have very good field quality in order to preserve the beam emittance when it passes through the magnets a large number of times. It is well-known that the coil-shape generated by two displaced elliptic current distributions of opposite signs produce a perfect dipole field in the overlapping region. Similarly two intersecting concentric elliptic current distributions produce the perfect quadrupole field. The coil-shapes of practical superconducting magnets which are used in LHC, RHIC etc. are variations of such ideal designs. No mention of ideal coil-shape for a perfect superconducting sextupole magnet is available in the literature. In the present work we have explored the field produced by various coils shapes and found a coil shape which is capable of generating the perfect sextupole field. Parametric equation has been given for the x-y profile of the boundary of the coil cross-section. This finding should be useful in designing practical sextupole coils.  
 
THPMA045 Analysis and Design of Parallel Resonant Network Power Supply for a Rapid Cycling Synchrotron synchrotron, power-supply, proton, target 685
 
  • S. R. Tiwari, M. Borage, K. Swarna
    RRCAT, Indore (M. P.)
  Rapid Cycling Synchrotron (RCS) requires dc biased sinusoidal excitation for electromagnets. Power supplies based on resonant schemes are best suited for such applications, as only the losses of the resonant network are drawn from the mains and the magnets are energized by resonating its inductance with external energy storage elements. In this paper study of various options for powering the magnets and its excitation source is carried out. Optimization of network elements for parallel resonant network with respect to the operating and investment cost is carried out. Tolerance analysis of a high-Q resonant network with respect to variation in component values and its effect on amplitude and phase of magnet current, and the ac component reflected in the magnet current due to presence of ac and dc input source ripple is documented in detail. Design of a parallel , continuous ac excited resonant network for the QF2 magnet for the proposed 1 GeV Rapid Cycling Synchrotron is presented.  
 
THPMA047 Stair Current Output Power Supply for Switching Magnet controls, power-supply, feedback, electron 691
 
  • S.-H. Jeong, J. Choi, H.-S. Kang, D. E. Kim, K.-H. Park
    PAL, Pohang, Kyungbuk
  The switching magnet for beam distribution to 5 beamlines of 20-MeV PEFP is served with DSP-controlled PWM switching-mode converter. This converter is employed IGBT module and a DSP (Digital Signal Processor) that is operated at ?350A, 2.5 Hz stair output. Current feedback and input voltage feed-forward control schemes are applied to improve the output current stability. Designed filter result in the good stability of each stair. Simulation and experimental results show that the implemented converter achieves stable repeat response at each stair and feasibility for versatile power supply.  
 
THPMA081 Precise Positioning of Magnetic Field Centers of Quadrupole Magnets on the Girder laser, alignment, synchrotron, target 749
 
  • L. Tsai, T.-C. Fan, S. Y. Perng, D.-J. Wang
    NSRRC, Hsinchu
  Conventional alignment of quadrupole magnet on the girder is mainly based on the measurement of theodolite and fiducial. Most of the measurement errors come from human-eye resolution and fiducial precision. The resultant cumulative error could be in the order of 50~100μm. In this paper, pulsed wire method is proposed to align group of quadrupole magnets concentrically on one girder to precision about 10μm. In order to increase the alignment accuracy, sag problem in tension wire is replaced by a short wire with laser PSD system. Descriptions of the setup and test results are presented.

quadrupole magnet alignmentpsd

 
 
THPMA083 The Magnet Alignment Method For The J-PARC Main Ring target, alignment, site, sextupole 752
 
  • M. J. Shirakata, K. Ishii, K. Niki, K. O. Okamura, T. Oogoe, E. Yanaoka, M. Yoshioka
    KEK, Ibaraki
  In the J-PARC site, the inflastructure for the whole site measurement is planned for the global alignment of the accelerator components. For the neutrino experiments, the J-PARC main ring must be directed to the SUPER-KAMIOKANDE exactly. The global measurements from the Kamioka site to the J-PARC site is carried out by using GPS system on the gound level. Several measurement holes, in order to tranport the coodinates from the ground level into the accelerator floor level directly, are prepared around the J-PARC accelerator complex. The magnet alignment method for the J-PARC main ring are reported with the present alignment status.  
 
THPMA084 A Mechanical Installation Prototype for the SSRF Storage Ring vacuum, storage-ring, damping, dipole 755
 
  • L. Yin, H. W. Du, D. K. Jiang, X. Wang, Z. B. Yan, C. H. Yu, Q. G. Zhou
    SINAP, Shanghai
  The engineering design of the mechanical system for the SSRF storage ring was finished. The first group components in each system, such as the magnets, vacuum chambers, BPMs, girders and other hardware, were fabricated and tested, respectively. In order to check the overall design and the installation procedure, a lattice cell prototype was installed by using these components. Based on it, the related utility system was installed and checked. The dynamic properties of the magnet-girder assembly were also tested in this prototype. Most of the design was confirmed during the installation, but still some problems were found. The modification for the overall design and some components design has been made before their mass production. The detail design and installation of the cell installation prototype and the test results are described in this paper.  
 
THPMA086 Precise Survey and Alignment of Synchrotron Radiation Source Indus-2 alignment, controls, survey, dipole 761
 
  • V. Prasad, D. Barapatre, M. Jagannath, R. K. Sahu, K. P. Sharma, G. Singh
    RRCAT, Indore (M. P.)
  The 2.5GeV third generation synchrotron light source Indus-2 at RRCAT, which in advance stage of commissioning, demanded a high precision of survey and alignment of all its components. In particular, we had to control the transverse and azimuthal positions of all quadrupoles and dipoles within a relative accuracy of 0.1 mm and overall circumference within 2.5 mm. This required a tight control over all the sources of errors starting from fiducializations, survey of networks, final alignment and smoothing. We have successfully accomplished this task by adopting the triangulation-trilateration technique of survey and alignment along with indigenously developed software for online survey data collection, least square adjustment of redundant measurements and error analysis. The accuracy of alignment was reflected from the successful circulation and storage of electron beam in the machine with a very small closed orbit distortion. This paper, in brief, presents the methodology adopted for survey and alignment and final accuracies achieved.  
 
THPMA093 Vibration Evaluation for Utility Instruments and Water Piping System in TLS storage-ring, vacuum, controls, synchrotron 776
 
  • Y.-H. Liu, J.-C. Chang, J.-R. Chen, D.-J. Wang
    NSRRC, Hsinchu
  In order to design the brightness new synchrotron light source-TPS in NSRRC. The vibration issue is more restrict nowadays. The position stability in subsystems is important to beam dynamic performance. The vibration source from utility systems is one source of the instability factor. The purpose of this paper is to estimate the vibration source from water systems, AHU systems and the piping system in utility group. Analysis the vibration path from ground and the piping system is the first step. Then, propose the feasible proposals to eliminate the vibration source and reduce the vibration propagation path. The construction standards for water systems and AHU systems will be established before design. The test is based on TLS operating systems. Besides, the distance and path between utility building and storage ring is another factor for vibration propagation. To eliminate the vibration source and propagation path in TLS will be the next step. The experimental results will be the foundation of TPS construction in the future.  
 
THPMA114 Activities on the Nuclear Data Measurement at the Pohang Neutron Facility Based on Electron Linac electron, target, linac, background 800
 
  • G. N. Kim
    Kyungpook National University, Daegu
  • M.-H. Cho, I. S. Ko, W. Namkung
    POSTECH, Pohang, Kyungbuk
  • H.-S. Kang, Y. D. Oh
    PAL, Pohang, Kyungbuk
  We report the present status of the Pohang Neutron Facility which consists of an electron linear accelerator, a water-cooled Ta target, and a 12-m time-of-flight path. We measured the neutron total cross-sections in the neutron energy range from 0.1 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 Ta, Hf, Ag, and Mo samples are in general agreement with the evaluated data in ENDF/B-VI. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones.