The Study of the Diffraction of Protons of Medium Energy by Vapor Molecules

Abstract

The diffraction of 15–20 kv protons by carbon tetrachloride vapor has been investigated with a low voltage arc source and electrostatic focusing with photographic registration. The principal difficulties encountered were with space charge dispersion of the beam near the ion source, and with neutralization of the beam as it passed through the vapor. The cross sections for neutralization and re-ionization of protons and hydrogen molecular ions in several gases and vapors were determined. The sensitivity of photographic film was found to diminish as the emulsion was outgassed but to increase fifteen-fold when it was treated with oil. When suitable precautions were taken to minimize the background scattering, diffraction patterns were obtained showing three maxima, the measurements of which are in satisfactory agreement with electron diffraction data.