Excitation cross-section of pottasium by electron-impact

ABSTRACT: Despite of some well known drawbacks classical theories are useful for estimating the cross– section. The quantum mechanical principles are assumed to be well understood in the low energy atomic physics, anyway, their application to a complete atomic system comprises enormous technical difficulties, therefore, it is required to simplify the atomic system conceptually and develop mathematical approximation. The experimental results which are available are not enough and in many cases reliable experimental results are very difficult to gain. However, all the required data are not expected to be provided by the experimental any way, this is one of the fields where the theory is far away from the experiments, thus theoretical investigation have two distinct aims: 1. To improve the basic understanding of the underlying processes. 2. To provide simple methods to obtain reasonable estimates of the cross section for the processes hence the much needed data. Several works have calculated theoretically and experimentally the results are found to be in better agreement with experimental results than those of the combined classical theory or micro-canonical distribution and also the first born approximation