Recoil Studies of High-Energy Fission of Bismuth and Tantalum

Abstract

The recoil properties of a number of fission fragments formed in 450-Mev proton bombardment of bismuth and tantalum have been investigated radiochemically. The ranges of the fragments emitted in the direction of, and perpendicular to the beam were measured. The kinetic energies of the fragments were obtained from the measured ranges using a previously determined range-energy relation. The total average kinetic energy released in fission was found to be 111 Mev for bismuth and 96 Mev for tantalum. The energy deposited in the target nuclei for processes leading to the observed fragments was obtained from the forward-backward asymmetry and the other measured recoil parameters, and a momentum-deposition energy relation from recent Monte Carlo calculations. The average deposition energy in the fission of bismuth and tantalum was found to be 160 Mev and 190 Mev, respectively.