Enhanced copper K-alpha radiation from a low-energy plasma focus

A low-energy (2.3 kJ) plasma focus is operated in an enhanced Cu K-alpha li ne emission mode. The emission is dominated by the interaction of electrons in the current sheath with the anode tip. The Cu K-alpha line radiation of 0.4 J/sr is recorded in the side-on direction, which steadily increases in the end-on direction and attains the value of 0.8 J/sr. It is estimated ab out 40 J of energy is radiated as x rays, out of which 8 J is in the form o f Cu K-alpha lines in 4 pi geometry. The radiation yield represents a syste m efficiency of 1.7% for overall x-ray emission, and 0.35% for the Cu K-alp ha line. (C) 2001 American Institute of Physics.