Changes between Version 21 and Version 22 of docs/CommissioningPlan/P1.6

Timestamp:

02/14/22 16:50:22 (3 years ago)

Author:

kradhakrishnan

Comment:

--

docs/CommissioningPlan/P1.6

@@ -27 +27 @@
 **Notes**
 - This activity can run in parallel with other cleanroom activities (which do not need a cold detector).
+- Vacuum Pump details, usage and LN2 fill/refill: First, we need to pump a guard vacuum on a dewar. This requires a pump capable of pressures below 1 mTorr. Although a diffusion pump is capable of providing a high vacuum, a turbo pump would be preferable. A pressure gauge capable of reading below the 1 mTorr range is also essential for determining the extent of high vacuum achieved. When we reach the guard vacuum on the dewar, we need to valve the dewar onto a turbo pump. If a turbo pump is not available, a diffusion pump is acceptable. If a diffusion pump is used, make sure that the pump's cold trap is filled with liquid nitrogen. Yes, the cryostat shall be pumped off from the day before LN2 refilling, and be on UPS (so if the power goes off the pump is still working, otherwise we risk losing the vacuum in the cryostat). The dewar to the pump interface is a KF-25 vacuum flange. Regarding the LN2, for the first fill, we would require 40L. For every refill in 48 hours, we would require about 15-18L of LN2.
 
 **LBTO support**
 - Liquid Nitrogen refill is required in the cleanroom.
-- Vacuum pump and support for cooling down the cryostat. We do not yet the dimensions of the vacuum pump and how the LN2 refill will take place. If they will be done using long hoses then both vacuum pump and LN2 tank can stay outside the clean tent.
+- Vacuum pump and support for cooling down the cryostat. We do not yet have the dimensions of the vacuum pump and how the LN2 refill will take place. If they will be done using long hoses then both vacuum pump and LN2 tank can stay outside the clean tent.
+- See the Notes section above for more details about the vacuum pump and the amount of LN2 required (for first fill and every other refills).
 
 **Date performed and by whom**