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storage-ring

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PM17 Development of a Permanent Magnet Residual Gas Profile Monitor With Fast Readout diagnostics, heavy ion, instrumentation, synchrotron 134
 
  • T. Giacomini, P. Forck
    GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
  • V. Skachkov, A. Gobulev, D.A. Liakin
    ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
  • A. Vetrov
    MSU, Moscow State University, MSU, Moscow, Russia
  Modern ion accelerators and storage rings require very fast beam profile measurements (turn-by-turn) with highest resolutions. We propose a new residual gas monitor, which will operate on secondary electrons whose trajectories are localized within ∅ 0.1 mm filaments along 0.1 T uniform magnetic field lines excited by a permanent magnet. The best way to adopt the resolution of 0.1 mm into the data acquisition system is the use of a CCD camera with upstream MCP-phosphor screen assembly. To realize a fast turn-by-turn beam profile measurement a photodiode readout by a 100-channel amplifier/digitizer is foreseen.  
 
PM19 Ionisation Beam Profile Monitor at the Cooler Synchrotron COSY-Jülich diagnostics, instrumentation, ion, synchrotron 140
 
  • V. Kamerdzhiev, J. Dietrich
    IKP, Forschungszentrum Jülich, Germany
  For beam profile measurements, a residual-gas ionisation beam profile monitor using a position sensitive micro channel plate (MCP) detector was developed and installed at the cooler synchrotron and storage ring COSY at Forschungszentrum Julich. A parallel ion drift field is maintained in the gap between two electrodes. Residual gas ions are drifted onto an MCP assembly that provides a charge gain of about 107. For online calibration the detector can be illuminated with an α-source. The secondary charge produced from each ion is collected by a wedge and strip anode. After some processing the charge signal is digitized and read out by means of a PC running Cobold PC software. Since COSY operates with beam intensities up to 1011 protons and a vacuum of 10-9 mbar, there is a high risk of detector damage. The lifetime of the channel plates and the event rate are crucial issues for the profile measurement of intense proton beams. The aging of the channel plates (i.e. inhomogeneous decrease of the gain) were investigated using scanning electron microscope and energy dispersive x-ray microanalysis. Different implemented detector protection mechanisms are discussed. Measurements with electron cooled beams are reported.  
 
PT01 Beam Position And Phase Measurements Using A FPGA For The Processing Of The Pick-Ups Signals diagnostics, pick-up 169
 
  • G.A. Naylor, E. Plouviez, G.F. Penacoba
    ESRF, European Synchrotron Radiation Facility, Grenoble, France
  We have implemented the signal processing needed to derive the transverse beam position and the beam phase from the signals of a four electrodes BPM block on a FPGA (field programmable gate array). The high processing rate of a FPGA allows taking the full benefit of the high data acquisition rate of the most recent ADC circuits. In addition, it is possible to implement on a FPGA a processing algorithm exactly tailored to the measurement of the beam parameters. The efficiency of the signal processing has also been improved by a careful choice of the frequency of the sampling clock and of the RF front-end local oscillator, which are derived from the storage ring RF frequency. This paper describes the BPM, the RF front-end electronics and the FPGA algorithm. It presents some of the application of this BPM at ESRF and gives measurement results.  
 
PT19 Transverse Feedback System For The Cooler Synchrotron COSY-Jülich - First Results synchrotron, beam cooling, beam-losses, coherent-effects, damping, feedback, kicker, pick-up 214
 
  • V. Kamerdzhiev, J. Dietrich, I. Mohos
    IKP, Forschungszentrum Jülich GmbH, Jülich, Germany
  The cooler synchrotron COSY delivers unpolarized and polarized protons and deuterons in the momentum range 300 MeV/c up to 3.65 GeV/c. Electron cooling at injection level and stochastic cooling covering the range from 1.5 GeV/c up to maximum momentum are available to prepare high precision beams for internal as well as for external experiments in hadron physics. In case of electron cooled beam the intensity is limited by transverse instabilities. The major losses are due to the vertical coherent beam oscillations. To damp these instabilities a transverse feedback system is under construction. First results with a simple feedback system are presented. Due to the feedback system operation the intensity and lifetime of the electron cooled proton beam at injection energy could be significantly increased. Measurements in frequency and time domain illustrate the performance of the system.  
 
PT25 Fast Tune Measurement System for the ELETTRA Booster booster, diagnostics, electron, instrumentation 231
 
  • M. Ferianis, S. Bassanese, F. Iazzourene
    ELETTRA, Sincrotrone Trieste, Trieste, Italy
  Since several years, the Diagnostic Group at Laboratori Nazionali di Legnaro (LNL) has been designing Fast Faraday Cups (FFC) to be used on their Heavy Ion Accelerators; latest developments in this field include a stripline FFC, jointly developed with SNS, Oak Ridge. A collaborative partnership has been set-up between LNL and ELETTRA Laboratory to fully characterize new FFCs, using as electron source the ELETTRA 1 GeV Linac. Two FFCs, the stripline FFC, built at SNS, and a coaxial FFC, made at LNL, have been installed at ELETTRA who provided the wideband data acquisition and the remote control of the measurement. The first measurements carried out using 1 GHz oscilloscope allowed the proper set-up of remote control and a low jitter triggering. Wideband measurements were performed with a sampling scope equipped with 50 GHz head whereas the bandwidth of the stripline FFC is in the order of 10 GHz. A complete set of tests has been carried both on the coaxial FFC and on the stripline FFC. Thanks to the information provided by these wideband measurements, the Linac working point has been further optimized as well as the injection process into the ELETTRA SR.  
 
PT28 Current Measurements of Low-Intensity Beams at CRYRING diagnostics, pick-up 240
 
  • A. Paal, A. Simonsson, A. Källberg
    MSI, Manne Siegbahn Laboratory of Physics, Stockholm, Sweden
  • J. Dietrich, I. Mohos
    IKP, Forschungszentrum Jülich GmbH, Jülich, Germany
  The demand for new ion species leads to an increasing number of cases in which the ions can only be produced in small quantities. Thus, weak ion currents quite often have to be handled in low energy ion storage ring, like CRYRING. Various detector systems have been developed to measure such low intensity coasting and bunched beams by using the overlapping ranges of those systems.
  1. We have extended the RMS resolution to 1 nA of the Bergoz Beam Charge Monitor (BCM) by using a low noise 60 dB preamplifier for the Integrating Current Transformer.
  2. The sum signal of a capacitive pick-up is integrated by a second gated integrator and the BCM output signal is used for calibration. The RMS resolution is about 100 pA..
  3. To measure the coasting beam intensity, neutral particle detectors have been built. The fast Microchannel plate detector can handle 1 Mc/s, and a 50 Mc/s Secondary Electron Multiplier based detector is under construction. On the magnetic flat top, a time of 100 ms is available to calibrate the count rate of the neutral particle detectors during each machine cycle.