Abstract
Some radioactive products from the gases produced in the fission of uranium by slow neutrons have been studied as to their chemical identity and characteristic half-life periods. Two Rb activities have been observed, one of which decays with a period of 15.4±0.2 minutes into an active Sr with a half-life of 51±2 days; the other decays with a period of 17.8±0.2 minutes into an apparently inactive end product. The parent of the 15.4-minute Rb is a gas with a half-life of a few minutes whereas the other Rb arises from the decay of a 175±10-minute Kr. Absorption in Al indicates the maximum -particle energy for these active products to be 3.8 Mev for the 15.4-minute Rb and 4.6 Mev for the 17.8-minute Rb. In a similar manner, a Cs has been observed which decays with a 32±0.5-minute period into a Ba which is inactive or of very long or short period with no evidence of the 300-hour product reported by Hahn and Strassmann. Data have been obtained which indicate that this long period Ba arises from the decay of a product of a very short period gas. This 32-minute Cs results from the decay of a Xe with a half-life of 17±1 minutes. Absorption in Al indicates a maximum -particle energy of 2.6 Mev for this Cs activity.
- Received 13 May 1940
DOI:https://doi.org/10.1103/PhysRev.58.1
©1940 American Physical Society