Determination of W Values and Backscatter Coefficients for Slow Electrons in Air

Abstract

Measurements are reported to determine the average energy W expended to form an ion pair in air for incident electrons in the energy range from 30 eV to 5 keV. For energies T greater than or equal to 60 eV the standard deviations are lower than 1%. In addition, backscatter coefficients R/sub i/ with respect to the spatial ionization distribution have been determined. R/sub i/ is an important quantity describing the electron transport in matter and is needed to correct W values. The experimental data are compared with the results of other authors.