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 [math]\displaystyle{ 10^{-4} }[/math] 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 [math]\displaystyle{ 10^{-5} }[/math] or [math]\displaystyle{ 10^{-6} }[/math] 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 [math]\displaystyle{ 10^{-3} }[/math] 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[math]\displaystyle{ *10^{-5} }[/math] mbar (~4.2[math]\displaystyle{ *10^{-5} }[/math] Torr). While the cryostat is held around 5 K and continuously pumped down, the pressure gets as low as 4[math]\displaystyle{ *10^{-8} }[/math] mbar (~3[math]\displaystyle{ *10^{-8} }[/math] Torr).