EXPERIMENTAL RESULTS OF CASCADE STATIC LENS GAUGE

A new ionization gauge of the 'cascade static lens (CSL) gauge, which has high sensitivity (S) and operates with weak emission current (I(e)), was studied. In the gauge, apertured electrodes forming a cascade electrostatic lens system are installed between the cathode and the ion collector, allowing the electrons to oscillate many times between the cathode and the ion collector under the focusing effect of the lenses. Suitable electrode potentials were studied by computer simulation. The experimental value of S = 22. 1 Pa-1 (2870 torr-1) with I(e) = 4 muA was obtained rather easily, and the linearity was confirmed in the measured pressure region (8 x 10(-8) Pa approximately 1.5 x 10(-5) Pa).