Absolute partial cross sections for electron-impact ionization of SF₆ from threshold to 1000 eV

R. Rejoub, D. R. Sieglaff, B. G. Lindsay, and R. F. Stebbings

J. Phys. B: At. Mol. Opt. Phys. 34, 1289-1297 (2001)

Absolute partial cross sections for electron-impact ionization of SF₆ are reported for electron energies from threshold to 1000 eV. The product ions are mass analyzed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that all product ions are collected with equal efficiency irrespective of their initial kinetic energies. Data are presented for the production of SF₅⁺, SF₄⁺, SF₃⁺, SF₂⁺, (SF⁺ + SF₄²⁺), S⁺, F⁺, SF₃²⁺, SF₂²⁺ and SF²⁺ and for the total cross section which is obtained as the sum of the partial cross sections. The overall uncertainty in the absolute cross sections for singly charged ions, except S⁺, is ±5%; that for S⁺ is ±8%. The uncertainty in the cross sections for doubly charged ions is ±12-15%. Data are also presented for formation of (SF_n⁺, F⁺) ion pairs. Comparison is made with prior experiments and calculations.