alpha-particle knock-on signature in the neutron emission of DT plasmas

The fast alpha-particle kinetic effects in fusion plasmas of deuterium and tritium are studied in the perspective that they can give rise to minority populations of fast fuel ions. The resulting modification of the neutron emission spectrum is computed for a plasma in the state of steady thermonuclear burn of conditions similar to those envisaged for the planned ITER tokamak. The nuclear interaction in these scattering alpha-particle knock-on processes is taken into account explicitly and the dependence on plasma parameters is investigated. The findings provide evidence that neutron spectrometry is a potential diagnostic of the fast alpha-particle population in burning fusion plasmas.