ISIS status report

Two years back, I reported at ICANS X that ISIS was running regularly at 100 μA, 750 MeV, with 9 scheduled neutron instruments and one muon beam line. Overall efficiency, measured as a percentage of time beam on target, was about 72%, and our stated priority was to improve reliability at 100 μA current. Over the past two years, major improvements have been made to several component parts of the system, and reliability so far in 1990 is just below 80%. Regular running periods at 100 μA have been achieved, with 100 μA average current achieved over a period of over a week. On 3 November 1989 a record integrated current over 24 hours of 2571 μA hrs was obtained. Trip rates have been significantly reduced. Three more neutron instruments are now scheduled, bringing the total to 12 neutron and 1 muon instruments. Around 350 neutron experiments were run in the 7 cycles of 1989, and about the same number are expected to be run in the 6 cycles of 1990. (author)