Excitation of doublet states of HfII from the ground state of the hafnium atom

Hafnium has not found great industrial use as a result of its limited availability and high cost, which is due to the difficulty of its separation from zirconium. However, in recent years the field of its use has substantially broadened as a result of the improvement of the technology of preparation (with a corresponding decrease in cost), and as a result of more detailed study of its properties. In particular, the collection of characteristics of hafnium makes it a valuable component of contemporary neutron absorbers. Besides, heat-resistant alloys containing hafnium are finding ever wider use. One of the basic means of preparation and purification of hafnium, and also processing of its alloys is electron-beam melting. Using this method partial vaporization of the material occurs, which leads to the appearance of atoms and ions of hafnium in the vacuum chamber. For problems of diagnostics of the gas phase in electron-beam setups, and also for calculation of the characteristics of the plasma containing hafnium atoms and ions, information on the cross sections of inelastic collisions of hafnium with electrons of low and medium energies is necessary. Such information may be obtained by the method of crossed beams, which in the case of hafnium is realized with considerable difficulties as a result of the fact that the melting temperature of hafnium reaches 2500 K and its saturated vapor pressure at the melting point does not exceed 0.13 Pa. The development and improvement of the method of extended crossed beams in recent years has provided the possibility of increasing the reliability and informativeness of the experiment. Using this method in this work excitation of spectral lines of HfII under inelastic collisions with hafnium atoms was investigated