Electron impact ionization cross sections of SiF2

Absolute cross sections are measured for electron impact ionization and dissociative ionization of SiF2 from threshold to 200 eV. A fast (3 keV) neutral beam of SiF2 is formed by charge transfer neutralization of SiF+2 with Xe; it is primarily in the ground electronic state with about 10% in the metastable first excited electronic state (a 3B1). The absolute cross section for ionization of the ground state by 70 eV electrons to the parent SiF+2 is 1.38 +- 0.18 A2. Formation of SiF+ is the major process with a cross section at 70 eV of 2.32 +- 0.30 A2. The cross section at 70 eV for formation of the Si fragment ion is 0.48 +- 0.08 A2. Ion pair production contributes a significant fraction of the positively charged fragment ions