Influence of electron collisions inside the cathode sheath upon the electron energy spectrum in the negative glow region of a gas discharge

Computer models developed to solve the Boltzmann equation for the electron energy spectrum in both the cathode sheath and the negative glow region of a glow discharge are discussed. Electron collisions occurring during acceleration inside the cathode sheath partially determine the structure of the electron energy distribution measured in the negative glow. The relative roles of elastic, excitation, and ionization collisions are examined using the computer model. Good qualitative agreement was obtained between calculated electron energy distributions and previous experimental measurements both at the sheath-plasma interface as well as in the negative glow region of the discharge.