A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  

Mathieson, R.J.

Paper Title Page
MOPEC063 Wideband Low-output Impedance RF System for the ISIS Second Harmonic Cavity 609
 
  • Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, A. Takagi
    KEK, Ibaraki
  • D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • J.C. Dooling, D. Horan, R. Kustom, M.E. Middendorf
    ANL, Argonne
  • T. Oki
    Tsukuba University, Ibaraki
  
 

A low-output-impedance RF system for the second harmonic cavity in the ISIS synchrotron has been developed by collaboration between Argonne National Laboratory (US), KEK (Japan) and Rutherford Appleton Laboratory (UK). The system has less than 30 Ω of output impedance over wide frequency range of 2.7-6.2 MHz. However, distortions of voltage waveform in the driver stage have been a long-standing issue. It was found such distortions were generated depending upon the higher-order-modes of the anode-choke impedance. In this report, method to realize the smooth sinusoidal waveform in the wideband system is presented.

  
MOPD016 Injection Upgrades for the ISIS Synchrotron 705
 
  • J.W.G. Thomason, D.J. Adams, D.J.S. Findlay, I.S.K. Gardner, S.J.S. Jago, B. Jones, A.P. Letchford, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon
  • C.R. Prior, G.H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  
 

The ISIS Facility based at the Rutherford Appleton Laboratory in the UK is the world's most productive spallation neutron source. Presently it runs at beam powers of 0.2 MW, with RF upgrades in place to supply increased powers for the new Second Target Station. Increasing injection energy into the synchrotron beyond the existing 70 MeV level has significant potential to increase intensity as a result of reduced space charge. This paper outlines studies for this upgrade option, which include magnet and power supply upgrades to achieve a practical injection system, management of increased injection region activation levels due to higher energy un-stripped particles and ensuring the modified longitudinal and transverse beam dynamics during injection and acceleration are possible with low loss at higher intensity levels.