Calculation of the cross sections for electron impact excitation of magnesium

There have been calculated the energy dependences of the electron impact excitation cross section for 50 transitions from the ground state of magnesium atom. Optically allowed, intercombined transitions and transitions occurring due to the nondipole interaction of an incident electron with atom ic electrons are involved. The calculations are based on the Born approximation with taking into account the exchange through the modified Ochkur approximation. As the ground state wave function there have been used either the familiar expansion of Hartree-Fock function over Slater exponents or the model potential wave functions. It was found that in the case of excitation of low states the model potential wave functions provides better agreement with experimental data and with data of other calculations. The agreement of results obtained with few available experimental data and data of other calculations is within 40%. There have been proposed simple approximating analytical expressions for the cross sections, which obey proper limiting energy dependences and permit to represent with sufficient accuracy the calculation results through two fitting parameters.