Angular Distribution of the Products of Artificial Nuclear Disintegration

Abstract

Measurements were made of the angular distribution of the alpha-particles emitted during the disintegration of lithium (7) by fast protons. The protons were generated in a low voltage arc and accelerated down a three-section vertical tube by potentials obtained from a rectifying and doubling system. The bombarding beam was analyzed by an electromagnet, defined by a series of circular slits, and allowed to impinge on the target in a special chamber designed to permit observation of the particles at positions spaced by 15° in the plane of the beam. The alpha-particles were recorded by an ionization chamber which actuated a linear amplifier and oscillograph. Readings taken at three voltages between 200 and 240 kilovolts indicate that within the limits of experimental error, estimated as approximately eight percent, emission of alpha-particles is random in direction.