Continuous emission from a low-temperature helium plasma due to radiative charge exchange and radiative ion-atom recombination

Abstract Radiative recombination and radiative charge exchange in symmetrical He + + He collisions are considered using a semiclassical adiabatic model of collisions in low-temperature plasmas. The reaction channels are assumed to be uncoupled and the corresponding total and partial spectral coefficients for the spontaneous continuous electromagnetic emission are calculated for helium-plasma temperatures below 3×10 4 K. The results are compared with the similar spectral densities for electron-ion and electron-atom scattering. It is found that in a wide range of physical conditions radiative processes involving ion-atom collisions should be taken into account in the analysis of the continuum radiation from helium plasmas.