Reduction of the isotropic S-formula for the energy spectrum of nuclear fusion products to a triple integral

Abstract

Energetic and angular distributions of the products of nuclear fusion reactions involving two colliding nuclei and two resulting particles are important in neutron spectrometry, as well as in studies of the behaviour of fast electrically charged particles in plasma, such as protons, tritons, helions and α-particles in the megaelectronvolt range. This also applies to primordial nucleosynthesis and astrophysics since the reaction rates in cosmic plasma can also be affected by suprathermal particles. The possibility of a reduction of the S-algorithm to a triple integral is demonstrated for the case of isotropic velocity distributions of projectile and target particles.