Tokamak ion temperature and poloidal field diagnostics using 3-MeV protons

The 3-MeV protons created by d(d, p)t fusion reactions in a moderately sized tokamak leave the plasma on trajectories determined by the position of their birth and by the poloidal magnetic field. Pitch-angle resolution of the escaping 3-MeV protons can separately resolve the spatial distribution of the d(d, p)t fusion reactions and the poloidal field distribution inside the tokamak. These diagnostic techniques have been demonstrated on PLT with an array of collimated surface barrier detectors.