New observation of space-parity violation in neutron-induced fission of 229Th, 241Pu and 241Am

The space-parity violating effect of the asymmetry of light fragment angular distributions relative to the polarization of cold neutrons inducing 229Th, 241Pu and 241Am fission has been observed for the first time with the following values for the P-odd asymmetry coefficients: -(5.6 ± 0.2) x 10-4, -(0.89 ± 0.04) x 10-4 and -(1.0 ± 0.25) x 10-4, respectively. In addition the following P-odd asymmetry coefficients have been obtained for 233U (used as a standard) and for the subbarier fission of 237Np: (3.67 ± 0.06) x 10-4 and -(3.3 ± 3.7) x 10-4, respectively. For all fissile targets studied, except 237Np, P-odd asymmetry coefficients for three separate intervals of the heavy fragment kinetic energy have been evaluated and found to be equal to the average values for each target. (orig.)