EVACUATING AND COOLING THE NICMOS3


Rafael Millan Gabet, March 2000
(rmillan@cfa.harvard.edu
We have had instructions on how to do this for a while, however I think that they don't emphasize enough the importance of BAKING the dewar while evacuating, in order for the detector to properly cool to about 77K.
  Do step (4) until the test port pressure reads about 10 mTorr.


Note:


Very Important!

Use a funnel with a long neck to fill the dewar inner can, so that it basically touches the bottom of the can. Otherwise, the LN2 will just  boil on its way down and fool you into thinking that the can is full.


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