ELASTIC SCATTERING OF 20-MEV. PROTONS BY OXYGEN AND NITROGEN

Abstract

The absolute angular distributions for 20-Mev. protons elastically scattered by O16 and N14 were determined using the external beam of the frequency-modulated cyclotron at the University of California, Los Angeles. The distributions for the two elements were found to be similar except for the appearance of a more pronounced first minimum in the O16 distribution. The locations of the maxima and minima seem to indicate that simple diffraction effect is responsible for their presence. The cross sections range from about 1 barn per sterad. to 4 mb. per sterad. between 15° and 165° in the laboratory system. The standard deviations due to statistics range from [Formula: see text] to 10%.