An ionisation gauge using a channel electron multiplier for pressures below 10−12ˆ\^{-12}

Since new techniques to achieve pressures of below 10/sup -12/ Torr have been developed, gauges with an appropriate low pressure limit are required. Channeltrons, with their high gain, seem to be the best means to construct gauges with high sensitivity. In this paper a new ionisation gauge using a channeltron has been described. (15 refs)

An ionization gauge using a Channel Electron Multiplier for pressures below 10−12^{-12} Torr

Since new techniques to achieve pressures of below 10/sup -12/ Torr have been developed, gauges with an appropriate low pressure limit are required. Channeltrons, with their high gain, seem to be the best means to construct gauges with high sensitivity. In this paper a new ionisation gauge using a channeltron has been described. (15 refs)

A miniature extractor gauge for the UHV

An extractor type ionization gauge has been developed for flange mounting in a 15.7 mm diam. aperture. The gauge electrodes are aligned by ceramic plates. A cylindrical anode grid of 9 mm diam. and 12.5 mm length is formed of photo-etched W-sheet. A thoria coated W-filament is employed made from two semicircular loops mounted outside and concentric with the anode grid. The two halves of the filament are connected in parallel. The height of the electrodes from the top of the anode grid to the base of the hemispherical collector is 18.9 mm. The gauge design is a compromise between obtaining a low X-ray or pressure limit, high sensitivity and high electron emission current. The foregoing, given in the same order, were respectively 5*10/sup -12 / torr; 5 torr/sup -1/ for N/sub 2/ at 10 mA emission current and 6 torr/sup -1/ at below 5 mA; and an emission current of between 5-10 mA which gave the high anode current density required to maintain a clean grid. (15 refs)

New deflected-beam gauge for pressures below 10/sup -12/ Torr

A new ionization gauge for measurement of total gas pressures between 10/sup -12/ torr and 10/sup -14/ torr is described. The gauge's main features are a pair of collimating slots below the grid structure, two concentric hemi-spherical deflecting electrodes and a channel electron multiplier which detects low-energy ions passing through the deflector system. The detection of low-energy ions allows discrimination against desorbed ions (which are more energetic), while spurious signals due to X-rays may also be rejected. The channel electron multiplier leads to gauge sensitivities which are much higher than those of ordinary ionization gauges. The gauge has been tested down to 4*10/sup -13/ torr and found to have sensitivities of 1.5*10/sup 17/ and 8*10/sup 16 / counts/s.A.torr for N/sub 2/ and H/sub 2/ respectively. For a channel electron multiplier gain of 10/sup 7/ the gauge sensitivity is thus approximately=10/sup 5//torr. (17 refs)