About boron–yes,the decaborane will break down after the first pulse. We don’t know yet if the boron will need to be gaseous or just going back and forth between a fog of liquid drops and gaseous when the pulse passes through. The plasma in the chamber will be hot, certainly 2000C or more and far hotter than the electrodes at 700-800 C–thus the cooling problem. Pressures won’t be very extreme–several atomospheres.