Pedro,

As a grad student I used aluminum foil and kapton tape to manually fix a
conductance throttle into a system.  The pressure was then adjustable by
the flow rate of the nitrogen bleed.  It worked fine, although crude.
Just a note, if you decide to use standard aluminum foil from a grocery,
it is coated with vegetable oil and requires a quick organic clean with
acetone/IPA to remove the oil.  Otherwise, it can contaminate your
chamber.

Regards,

Paul


> This is an excellent idea. The only problem I see with this is that our
> e-beam evaporation system in pumped -full blast- by a Cryo-pump. We would
> have to retrofit the high-vacuum pumping assembly with a butterfly valve,
> or other type of conductance control valve, to make it easier on the
> cryo-pump.
>
> Thank you very much,
>
> Pedro Barrios