The ISAC-II Accelerator team is making steady progress towards the goal of accelerating beam in ISAC-II by the end of 2005. Recent highlights include the first cool-down of the initial medium beta cryomodule and the commissioning of a Wire Position Monitor system for aligning the cold mass of the cryomodule.
The cool-down went very smoothly. The cold mass was cycled three times to LN2 temperatures (-196˚C) to check the repeatability of the alignment and, once to LHe temperatures (-270˚C), to check final alignment and static heat load. The measured static heat load of 10W was within the design estimate of 13W total for the cryomodule. This is important since the design value was used to specify the refrigerator. Also, the LN2 flow required to cool the thermal shield was determined to be ~5ltr/hr, also meeting the design estimates. The wire position monitor has been giving a wealth of new information that is being used to analyze the support structure of the cold mass. The alignment of the cold elements is found to be repeatable to 80microns vertically and 120 microns horizontally. The next step is to calculate the alignment offsets required to align all elements at cold temperature and prepare for the first cold rf test in June.
The accelerator group is also making steady progress with the acquisition of the phase I 500W refrigerator system. Linde expects to deliver the cold box and compressors before the summer end and TRIUMF is procuring the ancillaries (buffer tank, helium dewar, warm piping, etc) to allow commissioning of the plant by year end.