Characteristic x rays have been produced for a variety of samples by bombardment with protons in the energy range from 75 keV to 5 MeV. The experiments were performed with two accelerators. For the low-energy studies (less than 150 keV), a Cockcroft-Walton accelerator was used. The higher-energy studies were done with a 5 MV Van de Graaff. The x rays were measured with high-resolution Si(Li) and Ge(Li) detectors. Yields for the cross section of characteristic K- and L-shell ionizations were measured for titanium, vanadium, chromium, manganeses iron, cobalt, nickel, copper, silver, gold, bismuth, and uranium. The experimental cross-sections have been compared to the theoretical predictions of the Born approximation for an interaction of this type.Trace element analysis by 4-MeV proton bombardment of samples in the 10-12 gm range has also been performed. Some comments with regard to analysis with these sensitivities will be made.
