SCUBA-2 warm up

At the start of last week, we noticed the slow increase of gas pressures in the SCUBA-2 gas handling system. Historically, this has been a tell-tale sign of an impending blockage in the dilution fridge and that the instrument would not be able to hold the extreme sub 80mk base temperature, nor the temperature stability, required to operate our sensitive detector arrays for longer than a week.

And indeed, true to form, this past Saturday the instrument had to be warmed up to 4K and the precious Helium-3 recovered from the mixture. There are some useful engineering tests that can still be conducted at this temperature and these will be done before the instrument is brought up to room temperature later this week.

During this warm period, we will be fitting a new 4K cold trap into the gas handling system. The hope is that this will improve the cleanliness of the mixture removing any impurities that may be causing these blockages. In this way we hope to break the current warm-up cycle (currently every 5 weeks or so) and maintain base temperature for significantly longer periods.

We expect SCUBA-2 to be cold again, with a continuation of commissioning, on the 17th of March.


One Response to SCUBA-2 warm up

  1. Pingback: SCUBA-2 warm after 8-months of continuous operation « SCUBA-2 News Blog

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