Electron-impact excitation of even septet levels of an iron atom

Excitation of even septet levels of the iron atom by collisions with slow electrons is studied by the method of extended crossing beams. At an exciting electron energy of 50 eV, 72 excitation cross sections are measured. In the electron energy range of 0-200 eV, 15 optical excitation functions are recorded. The obtained results are used to evaluate the total excitation cross sections of the even septet levels.