Correlation between ion/electron distribution functions and neutron production rate in spherical inertial electrostatic confinement plasmas

Correlation between ion/electron distribution functions and device performance, i.e. potential structure, density profile and neutron production rate, in spherical inertial electrostatic confinement plasmas is studied by solving the Poisson equation for various deuteron and electron distribution functions. For several combinations of the ion and electron convergences, dependence of the total neutron production rate on discharged current is discussed. It is shown that when electrons have high convergence and energetic component compared with ions, the neutron production rate can increase in proportion to more than a power of the discharged current, even if the neutron production is sustained mainly by the fusion reactions between the beam (deuteron) and background (deuterium) gases.