Soft X-Ray Production by 1.5-MeV Protons

Thick-target yields of x rays with wavelengths from 1.5 to 44 Å have been measured as functions of bombarding proton energy near 1.5 MeV. X-ray production cross sections computed from these yields are in satisfactory agreement with existing theoretical excitation cross-section calculations insofar as current estimates of fluorescence yields permit comparisons to be made. Yields at 1.5 MeV of the ultrasoft x rays measured were, in quanta per proton steradian: ${\mathrm{Al}}_K$, 3.5×${10}^{-3\mathrm{}}$; ${\mathrm{Cu}}_L$, 9×${10}^{-4\mathrm{}}$; ${\mathrm{C}}_K$, 4.5×${10}^{-3\mathrm{}}$.