A normal 20 liter lecture bottle (smallest you can get, I believe) of D2 contains enough to fill, from a near perferct vacuum, a 1 liter fusor chamber almost 15 million times! I have squandered vast amounts of D2 in recent months with pressure releases from pressurized lines from multiple manifold and fusor take-aparts. I have run my fusor for many, many hours while continuously feeding flowing gas against a working pump. (exhausting the D2 while it is being admitted) The original pressure at the cylinder head was ~700 psi. It is now down to 200 psi.
Not bad for careless operation and many long runs. It is now three years since I purchased the thing for about $150.00. That works out to be $50.00/year for the D2 bill. Remember, I still have a good bit left on hand, too.
I don't think practice with hydrogen is a good idea based on the low price and micro amounts used of the real stuff, D2.
The amount of D2 in normal hydrogen is intrinsically zero for any fusion purposes in a fusor. Furthermore, I don't see the value of H2 runs providing useful data in a demo or test device just for the sake of working with the nearest analog to real D2. There will still be no real fusion.
Air makes the prettiest practice fusor runs in demo fusors. I obtained beautiful stars with air in fusor II. (see my website). Practice with the power feed and current demands is similar with air. I would suggest its use over any exotic. I tried argon, nitrogen and CO2. All were similar except for starting voltages and discharge color.
Richard Hull
Created on Sunday, January 14, 2001 12:20 AM EDT by Richard Hull