Optical Cryostat (Janis ST-100): Difference between revisions

Latest revision as of 15:41, 22 July 2014

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

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).

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 [https://wiki.physics.wisc.edu/yavuz/images/c/c3/ST-100_Drawing.pdf 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>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>10^{-5}</math> or <math>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>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 [[Turbo Pump Station (HiCube 80 Eco)|Pfeiffer turbo pump]] the pressure is pretty constant around 5.6<math>*10^{-5}</math> mbar (~4.2<math>*10^{-5}</math> Torr).  While the cryostat is held around 5 K and continuously pumped down, the pressure gets as low as 4<math>*10^{-8}</math> mbar (~3<math>*10^{-8}</math> Torr).