Abstract
Pre-neutron-emission fragment-mass and total-kinetic-energy distributions and the mass-energy correlations in the spontaneous-fission decay of 2.30-sec have been deduced from measured energies of coincident fragment pairs using silicon surface-barrier detectors. The for these measurements was produced in the reaction and deposited on 40-μg carbon foils using a He-jet technique. From an analysis of 154 correlated fission events, the average pre-neutron-emission total-kinetic energy, , was found to be 202.4±1.2 MeV. The mass distribution is decidedly asymmetric, similar to that observed for spontaneous fission, although a maximum in the curve as a function of fragment mass occurs for near-symmetric mass divisions as it does for the heavier isotopes of fermium. The measured spontaneous-fission-decay branching fraction for is 26.9±1.9% and the measured total half-life is 2.30±0.22 sec. The measured and deduced fission charàcteristics for are compared with those for the Cm, Cf, and Fm nuclides as well as with recent theoretical predictions.
RADIOACTIVITY, FISSION measured fragment-fragment coin , , , , for reaction; deduced pre-neutron fragment masses, energies, and total kinetic distribution. Enriched target.
- Received 4 November 1976
DOI:https://doi.org/10.1103/PhysRevC.15.705
©1977 American Physical Society