Paper | Title | Page |
---|---|---|
THPP136 | The Replacement of the Isis White-circuit Choke | 3679 |
|
||
ISIS, located at the Rutherford Appleton Laboratory is the worlds leading pulsed neutron source. It produces intense bursts of neutrons every 20mS when 800MeV protons are fired into a heavy metal target by an accelerating synchrotron. The ISIS synchrotron is based on a resonant White Circuit* allowing superimposed DC and AC currents to circulate in the ring of dipole and quadrupole magnets. The magnets themselves resonate with tuned capacitor banks at 50Hz and a large ten-winding choke allows both a path for the DC component of the current and a means to inject the AC power which maintains the 50Hz AC oscillation. This choke, which dates from the 1960s, was a veteran of the NINA synchrotron in Daresbury before it began service at ISIS. Should it fail it could take at years to repair and a scheme is now well under way to replace it with ten individual chokes with in-situ spares so that the system will gain redundancy and robustness. This paper covers progress to date and the problems that have been encountered and their solutions.
*M. G. White et al. "A 3-BeV High Intensity Proton Synchrotron," The Princeton-Pennsylvania Accelerator, CERN Symp.1956 Proc., p525. |