Abstract
The decay scheme of a 4.2-second neutron emitter has been investigated in detail. Chemical and physical evidence shows that it is , which emits beta-rays to a broad excited state of , which then breaks up into a neutron plus . The energy spectrum of the neutrons is determined by measuring the energies of the recoils in a proportional counter. The neutrons have a most probable energy of 0.9 Mev, a "half-width" of less than 0.5 Mev, and an upper limit of about 2 Mev. -recoil coincidences are observed, as predicted by the Bohr-Wheeler theory, and the -ray energy is measured by absorption. The beta-rays in coincidence with neutrons have an upper limit of 3.7±0.2 Mev. Beta-rays directly to the ground state of are not observed because of high background effects, but should have an energy of 8.7 Mev. Some evidence is presented to show that energy is conserved in the transition through the broad excited state in .
- Received 3 January 1949
DOI:https://doi.org/10.1103/PhysRev.75.1127
©1949 American Physical Society