Development of Synthetic Diamond Radiation Detector for Neutron Plasma Diagnostics

Abstract

A self-standing single-crystal CVD diamond was fabricated using a lift-off method. The reduction of charge trapping factors such as structural defects, point defects, and nitrogen impurities, was attempted using 0.2% of low-methane concentration growth and using a full metal seal chamber. A high-quality self-standing diamond with strong free-exciton recombination emission was obtained. Charge collection efficiencies were 100.1% for holes and 99.8% for electrons, provided that _εdiamond = 13.1 eV and _εSi = 3.62 eV. Energy resolutions were 0.38% for both holes and electrons. Finally, energy resolution of 0.78% for 14 MeV neutrons was achieved. Moreover, ToF measurement for DD neutrons of implosion experiment at Gekiko XII laser was succeeded.