🚀 go-pugleaf

In article <1992Aug26.194917.734@cs.ucf.edu>, clarke@acme.ucf.edu (Thomas
Clarke) says:
>
>In article <massoud.57@chemteca.sdsu.edu> massoud@chemteca.sdsu.edu (Massoud
>Ajami) writes:
>> In article <1992Aug26.043710.27944@vpnet.chi.il.us> cgordon@vpnet.chi.il.us
>(gordon hlavenka) writes:
>>
>>
>> >I have an _ancient_ laser which almost works.  It's a HeNe laser,
>> >model 3100 from Gaertner Scientific (circa 1969).  It worked for a
>> >while, but now has developed an electrical problem.
>>
>>
>> You have lost the gas. You woudln't expect helium gas stays in the
>> tube forever?
>>
>About five or six years ago I saw a little article in Applied Optics
>about rejuvenating olf HeNe tubes by putting the tube in a chamber
>with pressurized(?) He for a day or so.  The He would migrate back
>into the tube and after a while the tube worked just like new.
>Probably wouldn't want to overshoot though.  Can pressurize it in
>fairly quickly, but would have to wait years for too much to
>diffuse out again !-)
>--
>Thomas Clarke
>Institute for Simulation and Training, University of Central FL
>12424 Research Parkway, Suite 300, Orlando, FL 32826
>(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu

   Don't need to "pressurize", just need the partial pressure of He to
be greater outside than inside of the laser tube.  I did it once by
putting the laser inside of a garbage bag and filling it with He.  I put
in more He a couple of times a day, as the bag collapsed.  As I remember,
the laser came back to life in a couple of days, and continued to work for
at least several months.
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J. C. Hassler       Dept. of Chem. Eng.        U. of Maine
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