A compact recoil spectrometer for time integrated neutron energy spectrum measurements on the Z machine (invited)
O. M. Mannion, M. A. Mangan, D. J. Ampleford, P. Cahall, J. Frenje, M. Gatu Johnson, P. Lake, B. Lahmann, M. Lowinske, M. T. McCall, A. D. Norris, I. Rudnick, B. J. Ritter, K. L. Seals, F. Seguin, J. M. Swalby, J. A. Torres, T. J. Webb, G. WhitlowA 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.