A METHOD OF MEASURING ALPHA-GAMMA ANGULAR CORRELATION USING CATHODE PULSES IN A GRIDDED IONIZATION CHAMBER

An improved method of measuring the alpha-gamma angular correlation is proposed. The apparatus consists of a gridded ionization chamber and a NaI scintillation counter. In a gridded chamber, generally, the cathode pulse yields information on the emission angle of an alpha-particle, while the collector pulse gives information on its energy. Accordingly, the alpha-gamma angular correlation of mixed alpha-sources, in which some isotopes emitting alpha-particles of different energies and subsequent gamma-rays of almost the same energy are included, can be easily measured from the pulse height distribution of the cathode pulses coincident with the scintillation pulses and the collector pulses in the desired energy intervals, respectively. As examples, the angular correlation for two decay series in the daughter products of ThB, which are 1. ThC′*(γ)ThC′(α)ThD and 2. ThC(α)ThC″*(4+)(γ) ThC″(5+), were measured. The results are in good agreement with theoretical prediction and those obtained by other workers. © 1968.