Optical Cryostat (Janis ST-100)

Files

There is a hard copy of the manual in the lab.

Technical Drawing

Notes

Here are some random useful pieces of information to know gathered mostly from emails with Dan Logan from Janis:

• The ST-100 is designed to hold and operate at $10^{-4}$ Torr and the seals should hold this pressure for "several hours if not several days".

It seems like this is not the case.

• With continuous evacuation with a turbo pump the pressure should be able to reach $10^{-5}$ or $10^{-6}$ Torr, the ladish gaskets on the cryostat aren't able to hold this high of a vacuum without the pump on though.

• The performance of the cryostat will be better but the pressures as low as $10^{-3}$ Torr can be acceptable.

• The ST-100 should not be baked out because the window block and electrical feedthroughs are sealed using epoxy and baking out the cryostat might cause the epoxy to melt.

• What we've seen is that at room temperature while continuously pumping with the Pfeiffer turbo pump the pressure is pretty constant around 5.6$*10^{-5}$ mbar (~4.2$*10^{-5}$ Torr). While the cryostat is held around 5 K and continuously pumped down, the pressure gets as low as 4$*10^{-8}$ mbar (~3$*10^{-8}$ Torr).