Kinetic theory of photoelectrons and secondary electrons. I

The kinetic equation for photoelectrons or secondary electrons as given by Krinberg et al. (1970, 1973) is solved in a simplified form for electron energies greater than 25 eV. The solution is obtained in the form of a series of Legendre polynomials, allowing the calculation of the energy and pitch-angle distribution of photoelectrons or secondary electrons along force lines of the geomagnetic field for a given electron source of arbitrary form.