Oxford Intruments 3He Sorption Cryostat

HEOX is a 3He cryostat with a sorption 3He pump. All gas handling is inside the cryostat, there are therefore no tubes to a pump outside.

After putting into operation, some questions are still open:

Some test results

Hold times:

minimum T0.33 K22h
0.5 K25h
0.7 K32h

LS340 Settings:

Inelastic background on TASP

Operation with two heaters:

Heox starts up with the second PID loop (Analog Out2) enabled and loop 1 to control the temperature of the Sorb (Ch B)

The switch on the heater cable allows to operate the Sorb on loop 1 (the main loop) and simultaneously heat the 3He-pot with loop 2 and visa versa.

For low Temperature experiments <10K it is recommended to use: Sorb = loop1, 3He = loop2 while for higher temperatures Sorb = loop2, 3He = loop1 should be used. note: for the high temperatur setting the Cernox (channel C) should be used as the primary thermometer

You can operate the system by regulating the Sorb and the 3He-pot temperature independently (controlmode 0) or by using both heaters cooperatively to control the 3He-pot temperature (controlmode 1) in this case the setpoints for both loops should have the same value.

INPORTANT: both heaters are disabled if any setpoint is exactly zero. In order to control the Temperature using only 1 heater the other set value should be small (not reachable)


tt controlmode <n> ...sets control channel of loop 1 to B (n=0) or D (n=01)

tt set2 <n.n> ... setpoint of loop 2 in K

tt send pid n:P,I,D ... set PID values of loop n (1 or 2)

tt send cset n:<channel>,<unit>,<off/on>,<power enable> ...sets the channel (A,B,C,D) which will be used by loop <n> (e.g. tt send cset 2:D,1,1 sets loop 2 to control the 3He-pot heater

tt send pid?n query PID settings of loop n

tt send cset?n query control settings of loop n