Delayed neutron yield of $sup 238$U and $sup 241$Pu

The total delayed neutron yield for $sup 238$U and $sup 241$Pu were observed as a function of the incident neutron energy. The measurements extend from 2.5 to 5 MeV for $sup 238$U and from 0.15 to 5 MeV for $sup 241$Pu. The average ratio of the $sup 241$Pu delayed neutron yield to that of $sup 238$U is 0.292 +- 0.022