Atomic bremsstrahlung produced by light-ion-atom collisions below 1 MeV/amu

X rays from an Al target bombarded with protons of 0.5, 0.75, and 1.0 MeV/amu and ..cap alpha.. particles of 0.5 MeV/amu were measured with a Si(Li) detector. Production cross sections and spectra of the continuum radiation were obtained in the x-ray energy region of 2-6 keV and were compared with theoretical predictions for atomic bremsstrahlung (AB), secondary-electron bremsstrahlung, radiative ionization, and nuclear bremsstrahlung. Good agreement between theory and experiment is obtained. It is shown that in the region of bombarding energy less than 1.0 MeV/amu, atomic bremsstrahlung is the most predominant process. The Z/sub p//sup 2/ dependence of the AB production cross section, Z/sub p/ being the projectile charge, is experimentally confirmed, and the angular distribution of AB measured for 0.5-MeV/amu protons is found to be symmetric about 90/sup 0/ with respect to the incident beam, in agreement with the theoretical prediction.