INTERMEDIATE-ENERGY TOTAL CROSS-SECTIONS FOR ELECTRON-SCATTERING ON GEH4

Absolute total cross sections for electron scattering on GeH4 molecule s have been measured between 75 and 4000 eV. The dependence of the tot al cross section on energy is revealed to be different than for the li ghter hydrides, CH4 and SiH4. It has been noticed that in the high ene rgy limit the total cross sections for hydrides tend to the values of the corresponding isoelectronic noble gases. Self-consistency between different experimental partial cross sections and the absolute total c ross section is checked for CH4, SiH4 and GeH4. Upper limits for disso ciation into neutral fragments are set for these gases. By comparison of the partial cross sections selected in this way, a conclusion on di fferent partitioning schemes for noble gases and noble-like molecules (CH4, SiH4,GeH4) is drawn. At intermediate energies the inelastic proc esses dominate the electron scattering on molecules. At 100 eV the ela stic cross sections are almost equal for the pairs CH4-Ne, SiH4-Ar, Ge H4-Kr.