Since the pulse tube cannot be easily turned on and off, I added a few lines of code to determine how much power the heaters on the coldplate must emit at equilibirum to maintain a temperature of 123 K. For the Cryomech PT30RM, it is 11 W, while for the Sumitomo CH110, it is 19 W. There is a small risk that this value is an order of magnitude too low for the CH110 since it has a lot more cooling power at higher temperatures. I belive my modeling is correct, howerver. For the PT30RM, I belive 11 W is close to the actual value.

I think this implies we should have a high power heater near the coldhead's linkage to provide a rough constant temperature and a much smaller power heater on the beamsplitter mount to provide fine PID control.

See attached file