A3 Cool-Down Procedure for Closed Cycle Refrigerator

Step 1:

Check He-gas pressure p > 17 bar at compressor unit.

Step 2:

Install water cooling circuit.

Step 3:

After sample mounting check correct regulaion and sample temperature read out with Lakeshore 340; check heater function, also.

Step 4:

Mount vacuum can and start pumping isolation vacuum with separate turbo pump for p < 10-4 mbar.

Step 5:

Start cooling by switching on the main power switch at the compressor unit.