D-3He proton yield as a diagnostic for D-T and D2 filled inertial confinement fusion experiments

The ratio of D-3He to D-D reactions (RD3He/RDD) is proportional to fuel ρR for D2 and D-T filled targets. For D2 filled targets, the ratio varies as (RD3He/RDD)=0.14ρR, for ρR≲0.02 g/cm2. For present day D2 filled target experiments, it is necessary to detect 104 D-3He reactions against a background source of 108 D-D reactions. For D2 filled targets, detection of the 14.7-MeV proton of the D-3He reaction can be accomplished with sheets of the solid state nuclear track detector CR-39 and metal foils. Spatial coincidence can be used as a means of eliminating background due to imperfections in the track detector and background due to protons in the CR-39 which are elastically scattered by D-D neutrons.