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betatron

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TUPMA020 Beam Based Alignment and COD Correction for the Siam Photon Source quadrupole, photon, controls, alignment 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, quadrupole, dynamic-aperture 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.  
 
WEC3H101 Multi-bunch Feedback Activities at Photon Factory Advanced Ring feedback, kicker, injection, controls 330
 
  • W. X. Cheng, T. Obina
    KEK, Ibaraki
  The photon factory advanced ring (PF-AR) is a dedicated single bunch light source at KEK, however, some users require multi-bunch operation for high intensity x-ray beams. The old transverse damping system can suppress only one (or two) bunches, while new multi-bunch feedback system has been successfully tested to a maximum of 64 bunches. Both analog and digital transverse feedback loop has been tested at AR to store multi-bunches. Long cables are used to delay the bunch position error signal from BPM buttons for analog feedback control loop. Betatron phase advance between stripline kicker and BPM are selected to be around 90 deg. For digital feedback loop, it based on a FPGA test board. Bunch position error signal sampled by ADC, filtered by 10-tap FIR filter implemented in FPGA and send to DAC output for correction. FIR filter is well designed to increase the system dynamic range. Digital delay can also be implemented inside FPGA instead of long cable delays. Maximum beam current of 97mA has been achieved for several bunches’ storage, betatron oscillation of the stored beam can be suppressed well.  
 
WEPMA005 Magnetic Field Calculations of a 10 MeV High Current Compact Cyclotron cyclotron, extraction, injection, focusing 342
 
  • V. S. Pandit, A. Goswami, P. R. Sarma, P. Sing Babu
    DAE/VECC, Calcutta
  A 10MeV, 5-10mA 4-sector compact proton cyclotron, is being developed at VECC. A 2.45 GHz microwave ion source will produce ~30mA of proton beam at 100keV. It will be bunched and injected axially in the central region of the cyclotron where a spiral inflector will place the beam on the proper orbit. Two delta type resonators located in the opposite valleys will be used for providing acceleration to the beam. Beam will be extracted using an electrostatic deflector. The main aim of this project is to study and settle various physics and technological problems associated with the handling of high intensity beams. In this paper we present the results of design studies of the main magnet. The conceptual dimensions of the magnet and the properties of equilibrium orbits were first obtained using hard edge approximations and matrix method. The primary size of the magnet was estimated using 2D POISSON code. Finally a 3D code was utilized for the field calculation and optimization. The profile of magnet sectors was optimized to get the desired values of isochronous field and the betatron tunes.  
 
WEPMA013 Analysis and Correction of the Measured COD in INDUS-2 quadrupole, closed-orbit, synchrotron, injection 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.  
 
WEPMA049 Design of a Stripline Kicker for Tune Measurement in SESAME Storage Ring storage-ring, impedance, synchrotron, kicker 390
 
  • S. Varnasseri
    SESAME, Amman
  Traveling wave electrodes are commonly used in synchrtorn light sources as a tool for both excitation and beam sensing for tune measurement. Noraml longitudinally symmetric stripline has a posivie sine wave response in the frequency domain. An exponentially taperd stripline has a constant coupling impedance versus frequency and better frequency response. In this paper the design of stripline kicker for the purpose of tune measurement in the SESAME storage ring is reported.  
 
WEPMA065 Experience of Beam Diagnostic Systems in Commissioning Stage of Indus-2 diagnostics, injection, storage-ring, synchrotron 413
 
  • T. A. Puntambekar, L. K. Babbar, A. Banerji, A. Deep, A. C. Holikatti, D. K. Joshi, A. Karnewar, S. Kotaiah, M. Kumar, R. K. Nathwani, S. K. Suhane, Y. Tyagi, S. Yadav
    RRCAT, Indore (M. P.)
  Indus-2 is a 2.5 GeV synchrotron radiation source under commissioning at this center. Beam injection trials in the storage ring began in August 2005. Beam diagnostics systems played an important role during commissioning of the storage ring. Beam diagnostic systems installed in the machine include beam profile monitor, orbit measurement system, wall current monitor, DCCT, striplines, tune measurement system and sighting beam line. This paper describes the diagnostic systems, experience of operation of these systems during commissioning, results obtained and the present status. During the initial stages of beam injection and circulation in INDUS-2 wall current monitors, beam profile monitors and sighting beam line proved to be of utmost help. In the current stage of near routine beam operation, the main focus has shifted to the measurement of beam parameters with the objective of improving beam current and lifetime. A study of beam orbit measurement was recently taken up. The beam orbit was measured before and after generating an orbit perturbation. A study of betatron tune measurements has been initiated.  
 
WEPMA068 Comparison of the Methods for Beam Energy Spread Measurement at the VEPP-4M collider, wiggler, resonance, electron 416
 
  • A. N. Zhuravlev, V. Kiselev, O. I. Meshkov, N. Yu. Muchnoi, V. V. Smaluk, V. N. Zhilich
    BINP SB RAS, Novosibirsk
  The knowledge of beam energy spread is necessary for the experimental program of VEPP-4M collider. In this report we discuss the application of several diagnostics for studying of this value. We applied the Compton BackScattering (CBS) technique for direct measurement of the energy spread of the beam. The obtained data are compared with the value of the spread derived from the radial and longitudinal beam size as well as from betatron frequencies of the beam. The value of energy spread were determined for set of operating mode of the collider.  
 
THC3H103 The Compact Induction Circular Accelerator for Radiation Technologies induction, electron, acceleration, focusing 628
 
  • G. Dolbilov
    JINR, Dubna, Moscow Region
  The variant of the circular accelerator of electrons with energy up to 10 ?eV is discussed. Acceleration is carried out by an induction electric field on a constant equilibrium orbit of radius about 50 cm. For reduction of reactive power of the accelerator the alternating magnetic fields are concentrated in small volume near to the equilibrium orbit. Use of high-frequency magnetic fields (tens or hundreds ?Hz) allows to increase power of the accelerated electron beam up to some tens kW or hundred kW.