I am working on my new system too. I have a couple of new mass flow controllers obtained at east coast hamfests on hand and may try the same trick. They may be a bit "flowy" (100 scm or therabouts).
Steve is right to try and control the gas inlet flow to help maintain smooth pressure. It is a tricky deal at best with extra control gained by also close loop throttling of the vacuum pumping valves as well.
Fiddling with a dozen or more parameters really sucks, big time, but it does give one an inate "feel" for the dynamics of the fusor and an understanding for just what is happening and why.
I'll be glad to forego a bit of that "twiddling" in future having twiddled more than my fair share and having witnessed the relative smoothness of operation of Joe Zambelli's system first hand.
Richard Hull
Created on Monday, March 05, 2001 9:31 AM EDT by Richard Hull