STFC/RAL/ISIS, Chilton, Didcot, Oxon
ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Presently, it runs at beam powers of 0.2 MW, with upgrades in place to supply increased powers for the new Second Target Station. Studies are also underway for major upgrades in the megawatt regime. Underpinning this programme of operations and upgrades is a study of the high intensity effects that impose the limitations on beam power. This paper summarises work looking at the key topics of half integer resonance, image effects and injection painting under high space charge conditions, plus progress on overall machine modelling. A core aim of the work is to experimentally confirm simulations and theory, therefore progress on modelling the machine in both operational and specially configured modes is reported. Closely related diagnostics studies are also described, as is initial work on instabilities. Finally, future plans are summarised.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
ISIS is the world’s most productive spallation neutron source, at the Rutherford Appleton Laboratory in the UK. Presently, it runs at beam powers of 0.2 MW, with upgrades in place to supply increased powers for the new Second Target Station due to start operation in 2008. This paper outlines favoured schemes for major upgrades to the facility in the megawatt regime, with options for 1, 2 and 5 MW. The ideas centre around new 3.2 GeV RCS designs that can be employed to increase the energy of the existing ISIS beam to provide powers of ~1 MW or, possibly as a second upgrade stage, accumulate and accelerate beam from a new 0.8 GeV linac for 2-5 MW beams. Summaries of ring designs are presented, along with studies and simulations to assess the key loss mechanisms that will impose intensity limitations. Important factors include injection, RF systems, instabilities, longitudinal and transverse space charge.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ISIS is the spallation neutron source based at the Rutherford Appleton Laboratory in the UK. There are currently 227 individual diagnostic devices distributed between the 70MeV Linac, the 800MeV accelerator ring and the two target beam lines (TS1, TS2). This paper summaries the current state of the ISIS diagnostic systems and describes how the various diagnostics are used to tune the machine, to monitor beam intensity and beam losses and to provide fast machine protection. The limitations and accuracy of the various diagnostic systems (e.g. spatial and energy resolution, sensitivity, speed) are explored along with the steps that are being carried out to tackle any shortcomings. This paper will also briefly look at the new PXI based data acquisition and diagnostic control electronics used on ISIS and the problems encountered in using these systems within radiation environments.