SCUBA-2 warm after 8-months of continuous operation
November 18, 2011 3 Comments
It doesn’t seem that long ago when one of our major concerns with the SCUBA-2 project was the reliability of the fridge. In March, earlier this year, we installed a liquid Helium cold trap with the aim that it should filter out any contaminants that may have inadvertantly entered the He/He-3 gas mixture.
It’s astonishing how well this has worked. As the graph above shows, the fridge has kept its temperature all the way through the last 8 months, allowing us to control the temperature of the arrays at about 0.09 K. Furthermore, consider that the fridge was designed to only ever be cold for 6 months at a time.
So just this week, we initiated a controlled warm up of SCUBA-2 so that we can carry out some essential maintenance on the refrigeration system. We will be cooling the instrument back down in a few weeks and be ready for more observing with SCUBA-2 at the start of December.