Yield and Energy Spectrum of Secondary Electrons Generated by Fission Fragments

A technique for measuring the yield and energy spectrum of secondary electrons generated by the passage of a fission fragment through a metal foil is described. The electrons are accelerated through an electrostatic potential V and focused on a solid state detector using a lens. A number N of low energy secondaries are thus detected as a pulse corresponding to energy NV in coincidence with the fragment. An integral energy spectrum is obtained by using a suppression grid. The technique also yields information about the response of solid state detectors to electrons in the energy region below 30 kev.