Right now the copper at the top of the hole in the anode is too far away to get into the plasmoid, we think. It deposits all over the inside of the vacuum chamber and is certainly not in vapor form at the time of the next shot.
We hope that when the DPF is optimized almost all of the e-beam energy will be deposited in the plasmoid, leaving very little in the exiting beam.
Beryllium will be used in the generator and possibly in the experimental device if erosion by x-rays gets too severe.
