A Search for Short Period Activities fromU235Fission Products

Abstract

A search for gamma-ray activities with period 1-100 msec from thermal neutron fission of ${\mathrm{U}}^{235}$ gave negative results. 0.43±0.03 sec was the shortest observed. The period of ${\mathrm{B}}^{12}$ was found to be 27±3 msec. The cyclotron beam was pulsed to supply 1-10 msec neutron bursts. Coincidence scintillation detectors were employed.