I've only worked on YAG units with 6 coaxial lamps spaced at 60' around the rod. The rod was huge. Uniformity problems were solved by turning off one lamp and seeing what happens on the beam profiler. Turn off the worse lamp and use it as a spare. They go away to some extent if you use a oversized lamp and turn it down.
The type of coaxial laser I mean is one where the dye chamber wall is the inner wall of the lamp. Two coaxial tubes. The outer one holds the plasma.
In air, you may not be looking at Tungsten for all the electrodes.
For anodes and air spark gaps:
CU-TE alloys
w-cu alloys
Certain kinds of Brass
Brass works as a electrode well if its "seasoned" by firing it full blast into a small load.
I'd start with cerium doped welding rods.
Are you going to rely on pulling the vacuum down to fire the lamp, a triggered spark gap, or a baby Marx generator for triggering, or just the classic "dual" brass ball mechanical switch?
Going into any more detail on the above requires talking on the phone...
For reasonable tungsten:
www.tungsten.com. That does not get you activated or dispenser cathode tungsten, but they do sell to hobbyists. I've bought evap coils from their "deals" page for a song.
X-ray tube rotating anodes might be a source of large pieces.
Steve
Last edited by mixedgas; 07-29-2014 at 05:51.
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When I still could have...