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Kumar, A.

Paper Title Page
WEPMA039 Effect of Magnetic Field Coupling On INDUS-2 Quadrupole Magnets 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.  
WEPMA112 Thermal Simulations of a Photocathode R. F. Gun 482
 
  • B. Biswas, S. Krishnagopal, A. Kumar, S. Lal, K. K. Pant
    RRCAT, Indore (M. P.)
  
  We are developing a photocathode linac, which uses a 2856 MHz r.f. gun, with a copper cathode driven by a 102 MHz, 266 nm laser at inclined incidence. The laser photocathode r.f. gun is a 1.6 cell BNL/SLAC/UCLA type III r.f. gun. In this paper we present the dynamic thermal cooling simulations to calculate the structural deformations and consequent frequency drift of the gun. We have done a complete r.f.-thermal-structural-r.f finite-element analysis (FEA) of the gun in that order, using ANSYS/MULTIPHYSICS. We find that with the present coolant channel design the gun can operate at up to 2 Hz without any significant change in resonant frequency and field balance.  
THPMA039 300 kV/ 6 kW Power Supply System for Self-shielded Low Energy DC Accelerator at RRCAT Indore 679
 
  • R. Banwari, A. Kasliwal, S. Kotaiah, A. Kumar, T. G. Pandit, P. R. Peteti, A. Upadhyay
    RRCAT, Indore (M. P.)
  
  A compact, low energy, self-shielded dc accelerator for industrial applications requiring beam energy in the range of 100 to 300 keV is under development at RRCAT, Indore. The power supply and control system for this accelerator is discussed here in this paper. The high voltage source is a series fed cascade generator driven by a 30 kHz sine wave inverter. Two asymmetrical cascade generators are run in parallel to enhance the current capacity of the generator. A 15-0-15 kV, 30 kHz ferrite core transformer interfaces the cascade generators with IGBT based H-bridge inverter. A buck chopper controls the dc bus voltage of the inverter so as to control the terminal voltage of the high voltage generator. A low power high frequency inverter generates the filament power supply floating at terminal voltage of the accelerator through a capacitive isolation column. Control of the filament power supply is achieved by sensing the accelerator beam current and controlling the low power inverter in a closed loop. A PC based control system designed with Lab-view 7.0 software and ADUC812 Micro-converter cards monitors and displays the various parameters of the power supply and accelerator.  
THPMA085 Mechanical Coupling between the LHC Cryogenic Distribution Line and the Short Straight Section housing the Superconducting Quadrupole. Theoretical Analysis and Experimental Validation 758
 
  • S. Dutta, S. C. Bapna, J. Dwivedi, S. Kotaiah, A. Kumar, R. S. Sandha, H. C. Soni
    RRCAT, Indore (M. P.)
  • C. Garion, A. Poncet, B. Skoczen
    CERN, Geneva
  
  The cryogenic module of the Short Straight Section (SSS) of Large Hadron Collider (LHC) is supplied with liquid & gaseous Helium through a jumper connection, which links the valve distribution box of the Cryogenic Distribution Line (QRL) & the SSS. The internal as well as external features of the jumper construction allow for sufficient flexibility to reduce the reaction forces responsible for elastic deformations when the SSS is moved for alignment. The SSS is composed of a cold mass and an external vacuum vessel equipped with fiducials for allowing the precise alignment of the machine when the cryostat is finally closed. A deformation of the structure from reaction forces induced by relative displacements of the SSS and the QRL, if unpredictable, would result in a dangerous misalignment of the quadrupole magnetic axis. A unified FE model, validated by a 40 meter long dedicated test setup at CERN, was generated at RRCAT to study the elastic behaviour of the SSS under the conditions of alignment. Transfer functions linking the action on the SSS external alignment jacks and the position of the cold mass are now available that will be used to properly align the machine in operation.  
THPMA129 High Power Industrial Electron Accelerator 824
 
  • S. C. Bapna, R. Banwari, M. Borage, A. Kasliwal, S. Kotaiah, A. Kumar, P. Kumar, R. Promod, S. R. Tiwari, S. V. Venkateswaran
    RRCAT, Indore (M. P.)
  
  Development of 2.5MeV/ 100kW air-core transformer type electron Accelerator is in progress at RRCAT in collaboration with BINP, Russia. Energy of the accelerator is variable from 1 to 2.5 MeV with maximum beam current, power and beam scanning width of 50mA, 100kW and 1.5m respectively. High voltage generator, accelerating tube and injector control unit are housed inside the tank filled with pressurized SF6. A 430Hz, 150kW input power source to high voltage generator is based on a high-frequency switching (25kHz) dual half-bridge inverter and modular in construction with 6 modules (each 30kW) operating in parallel. In case one module fails, remaining modules will continue to feed power without de-rating. In this scheme, transformer leakage and magnetizing inductances will be compensated with high voltage capacitors eliminating the need of bulky inductors. The beam is scanned in two mutually perpendicular directions using scanning magnets. The control system uses microcontroller ADuC 812 based cards. Each subsystem will have one such card and a single RS485 multidrop communication link with the PC. The accelerator will be useful for various industrial applications.  
THPMA131 Indian Participation in LHC, SPL and CTF-3 Projects at CERN, Switzerland 829
 
  • V. C. Sahni, V. B. Bhanage, J. Dwivedi, A. K. Jain, P. Khare, S. Kotaiah, A. Kumar, P. K. Kush, S. S. Prabhu, A. Puntambekar, A. Rawat, A. Sharma, R. S. Shridhar, P. Shrivastava, G. Singh
    RRCAT, Indore (M. P.)
  • R. K. Sadhu
    BARC, Mumbai
  
  After signing a Protocol on 29 March 1996 to the 1991 cooperation agreement with CERN, Switzerland, India is participating in the construction of CERN’s most challenging and ambitious particle accelerator the “Large Hadron Collider” (LHC). The contributions span from hardware, software, and skilled manpower support for evaluation of some of the LHC sub-systems and presently to the support in commissioning of various subsystems of LHC. With major achievements on Indian part during the course of time CERN has now invited India to jointly participate further to build CERN’s Advanced Accelerator Projects like Super conducting Proton LINAC, SPL and Compact Linear Collider Test Facility, CTF-3. The present paper describes the achievements to date and high lights the ongoing and future collaboration activities.