THEORETICAL AND EXPERIMENTAL DESORPTION INVESTIGATIONS AT IONIZATION GAUGES

We have investigated the disturbing influence of outgassing and desorp tion effects on the pressure reading of three different types of ioniz ation gauges with different methods. The behaviour of these gauges aft er exposure to gases, which are important in the Ultra-High-Vacuum reg ion, after variation of the electron current, and for different potent ials of the electrodes were studied. We have also determined the influ ence of the grid material on the outgassing and desorption effects for the Chen-Suen gauge. General statements of the influence of desorptio n phenomena on the pressure reading of ionization gauges at the lower pressure limit are given.