OBSERVATION OF K-ALPHA X-RAY-SATELLITES FROM A TARGET HEATED BY AN INTENSE ION-BEAM

We have made the first observation of K-alpha X-ray satellites from a target heated by an intense ion beam. The satellites are produced when thermal ionization due to beam heating is accompanied by inner-shell ionization from beam ion impact. The Particle Beam Fusion Accelerator II was used to irradiate a conical aluminum target with a proton beam. The nominal beam parameters were 50-75 kJ in a 1-cm spot, 15-20-ns pulse length, and 4-5-MeV protons at peak power. An elliptical crystal X-ray spectrograph inside a 1000-kg tungsten shield was used to record the spectra. The peak ion stage reached by the aluminum target was +8. Collisional radiative calculations were performed, which indicate a peak electron temperature of 20-60 eV.