Plasma current sustained by fusion charged particles in a field-reversed configuration

Abstract

The distribution of energetic charged particles generated by thermonuclear fusion reactions in a field‐reversed configuration (FRC) are studied analytically and numerically. A fraction of the charged fusion products escapes directly while the others are trapped to form a directed particle flow parallel to the plasma current. It is shown that the resultant current density produced by these fusion charged particles can be comparable to background plasma current density that produces the original field‐reversed configuration in a D–³He reactor. Self‐consistent equilibria arising from the currents of the background plasma and proton fusion products are constructed where the Larmor radius of the fusion product is of arbitrary size. Reactor relevant parameters are examined, such as how the fusion reactivity rate varies as a result of supporting the pressure associated with the fusion products. A model for synchrotron emission from various pressure profiles is developed and it is shown quantitatively how synchrotron losses vary with different pressure profiles in a FRC.