Measurements of delayed-neutron yields from thermal-neutron-induced fission of 235 U, 233 U, 239 Pu, and 237 Np

The experimental results on delayed-neutron yields from thermal-neutron-induced fission of some actinides in the IBR-2 pulsed reactor are presented. A method of periodic irradiation without displacement of the sample was used. The measurements of delayed-neutron total yields in thermal-neutron-induced fission of 239 Pu, 233 U, and 237 Np and in cold-neutron-induced fission of 235 U, 233 U, and 239 Pu were carried out. All values were obtained with the use of the value of β 0 for ( n th + 235 U) as a reference. Precise measurements of decay curves in the time interval 5–350 ms for 235 U and 239 Pu were performed.