Simultaneous investigation of fission fragments and neutrons in 252 Cf (SF)
A gridded twin ionisation chamber is used to measure the kinetic energy, mass and angular distributions of the fragments of the spontaneous fission of 252 Cf. Together with a neutron time-of-flight detector, the correlations between neutron emission, fragment angle, mass and energy can be measured. About 3 x 1.0 E6 fission events were recorded in coincidence with a neutron detected in the time-of-flight detector. Angular distributions in the c.m. system revealed isotropy in the whole fission neutron energy range. It is concluded that fission neutrons are emitted from the fully accelerated fragments and that the scission neutron component is smaller. Extension of the mass range revealed two new saw-teeth near masses 80 and 176. The average neutron energy, the nuclear temperature, and the lambda-factor from the cascade evaporation model were evaluated from these spectra, and hence the level density parameter was found in the mass range 90 to 169.
Bibliographic Reference: Article: Nuclear Physics, Vol. A490 (1988), pp. 307-328
Record Number: 198910451 / Last updated on: 1994-12-01
Original language: en
Available languages: en