L-subshell ionization cross sections for tungsten at low electron energies

The L-subshell ionization cross sections for tungsten have been measured for incident electron beams of low energies. The electron energy was in the range of 1 < E/I/sub L/i < or = 4. The values of the three L-subshell cross sections sigma/sub L/1, sigma/sub L/2, and sigma/sub L/3 were deduced from the thick-target yields of Lβ3, Lβ1, and Lα1 x rays of tungsten. A differential method was employed in the deduction procedures. The x-ray spectra were obtained by an improved version of a single-crystal, high-angle goniometer. The shape of the energy dependence of the measured cross sections deviates from the predictions given by McGuire's scaling result as well as Gryzinski's classical scaling result