Fusion product studies via fast ion D–D and D–3He fusion on JET

Dedicated fast ion D–D and D–3He fusion experiments were performed on JET with carbon wall (2008) and ITER-like wall (2014) for testing the upgraded neutron and energetic ion diagnostics of fusion products. Energy spectrum of D–D neutrons was the focus of the studies in pure deuterium plasmas. A significant broadening of the energy spectrum of neutrons born in D–D fast fusion was observed, and dependence of the maximum D and D–D neutron energies on plasma density was established. Diagnostics of charged products of aneutronic D–3He fusion reactions, 3.7 MeV alpha-particles similar to those in D–T fusion, and 14.6 MeV protons, were the focus of the studies in D–3He plasmas. Measurements of 16.4 MeV gamma-rays born in the weak secondary branch of D(3He, γ)5Li reaction were used for assessing D–3He fusion power. For achieving high yield of D–D and D–3He reactions at relatively low levels of input heating power, an acceleration of D beam up to the MeV energy range was used employing 3rd harmonic () ICRH technique. These results were compared to the techniques of D beam injection into D–3He mixture, and 3He-minority ICRH in D plasmas.