[time-nuts] Maser info (vacuum levels)

Scott Newell newell at cei.net
Thu Sep 2 19:00:35 UTC 2010

At 01:17 PM 9/2/2010, Mark J. Blair wrote:

>Back in college, I took a semiconductor device physics course which 
>included a lab where we made simple ICs (the most complex devices 
>were SR latches). We had a vapor deposition system for plating on 
>gold or aluminum, which pumped the chamber down below 10E-12 Torr as 
>I recall, within ten minutes or so after a clueless freshman opened 
>the beast up and tossed in a bit of aluminum or gold wire and a few 
>chunks of silicon with their grubby hands (ok, we used tweezers, but 
>still...). The whole unit was about as big as a refrigerator or two. 
>It used a rotary-vane roughing pump and an oil diffusion pump with a 
>liquid nitrogen trap. This was about 25 years ago.

I think I took that same class (sub-basement of Steele, right?) just 
a few years after you.

newell  N5TNL 

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