An extended slowing down distribution function of alpha particles with non-uniform ion and electron temperature

We present an approximate expression for an isotropic alpha particle slowing down distribution function that is applicable down to the lowest velocity limit. The effect of non-uniform electron and ion temperature, i.e., the different rate of energy equilibration, is retained in this expression. Application of the extended slowing down distribution function shows that keeping the non-uniformity effect may have an influence on the alpha particle–background plasma interaction by the modification of the energetic particle contents in comparison with the conventional slowing down distribution function.