L-shell x-ray production cross sections in 26Fe, 28Ni, 29Cu, 30Zn, 31Ga, and 32Ge by 0.5- to 5.0-MeV protons

{ital L}-shell x-ray production cross sections by protons are reported for elements with x-ray energy between 704 and 1188 eV. The x rays were measured with a windowless Si(Li) detector. The efficiency of this detector, which is one of the major experimental problems for very-low-energy x-ray measurements, was determined by comparing spectra of atomic-field bremsstrahlung induced by 66.5-keV electrons on aluminum, silver, and gold with the theoretically known distributions. The x-ray production cross sections are compared with the first-order Born and perturbed-stationary-state theory with energy-loss, Coulomb deflection, and relativistic corrections of inner-shell ionization. Except for systematic but slight overpredictions of the data at the lowest proton velocities, both theories fit the measured data well.