Design consideration on compact neutron pinhole camera with nuclear emulsion for energetic-ion profile diagnostics

Abstract

For imaging of the emission profile of DD neutron produced by energetic deuterium ions, we propose a neutron pinhole camera with state-of-the-art nuclear emulsion technique. Recoiled proton due to elastic scattering of incident neutron passing though the pinhole makes a track in the nuclear emulsion. The incident neutron energy can be estimated by the energy of recoil proton and scattering angle that are derived from the track length and an angle between the track and the incident direction of neutron, respectively. DD neutron emission profile can be obtained with lower background events due to scattered neutrons and gamma-rays. We made preliminary designs on the pinhole collimator size and arrangement. The estimated spatial resolution would be better 100 mm with tungsten alloy collimator for the application to emission profile imaging of DD neutron in LHD plasma. © 2011 The Japan Society of Plasma Science and Nuclear Fusion Research.