A compact recoil spectrometer for time integrated neutron energy spectrum measurements on the Z machine (invited)

A new Compact Recoil Spectrometer (CRS) has been developed to measure time-integrated neutron energy spectra from inertial confinement fusion experiments on the Z machine. Recoil protons, generated as collimated neutrons from the experiment scatter in a hydrogen-rich converter foil located within the diagnostic, are measured with a CR-39 solid-state nuclear track detector. The recoil proton energy spectrum is inferred from the track diameter distribution measured on the CR-39 after chemical etching. The time-integrated neutron energy spectrum is determined from a forward fit to the measured recoil proton energy spectrum using a diagnostic forward model developed in MCNP. Example recoil proton energy spectrum measurements from magnetized liner inertial fusion experiments on Z are presented, and the primary deuterium-deuterium fusion yield and liner areal density are inferred.