Author: Ranner, J.
Paper Title Page
THPO021 A New Control System for the ISIS Main Magnet Power Supply 3385
 
  • J. Ranner, T.E. Carter, S. West
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory in Oxfordshire is a world-leading centre for research in the physical and life sciences. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of dipole and quadrupole magnets connected in series and configured as a White Circuit*. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. A recent upgrade to the main magnet power supply** involved the replacement of the original AC supply, a motor-alternator set, with a bank of four 300kVA UPS (uninterruptible power supplies) which had been modified to allow the output voltage to be varied using serial commands. However, when initially tested, this method was unable to produce the required stability in the main magnet current. This paper describes the further modifications to the UPS units to achieve the required stability and the development of a LabVIEW control system which manages the data acquisition and analysis, the communication to the UPS, interlock equipment and user interface, and provides a low latency control loop to the UPS and DC bias power supplies.
* M.G. White et al., “A 3-BeV High Intensity Proton Synchrotron”, CERN Symp.1956 Proc., p525.
** S. West, J.W. Gray, W.A. Morris, “Upgrade of the ISIS Main Magnet Power Supply”, EPAC 2004 p1467.