SU141669A1 - Ionization gauge - Google Patents

Description

Known ionization gauges containing thermal cathode, anode and collector of ions.

The proposed ionization manometer differs from the known ones in that the two grids located near the cathode and connected to a high-frequency voltage source are used to expand the lower limit of the measured pressures by smoothing electrons emitted by the cathode.

The described ionization manometer (see drawing) consists of a thermal cathode /, two grids 2 and 5 located near the cathode, anode 4 and collector 5. The electrons emitted by the cathode / are accelerated in the space between the cathode and grid 2. The grids 2 and 3 are connected to source 6 of the high frequency voltage. Depending on the phase of the alternating electric field acting on the electrons in the gap between the grids 2 and 3, the passing electrons are accelerated or slowed down.

In the space between the grid 3 and the anode 4, the electrons fly at different speeds, and those electrons on which an accelerating field acted in the gap will gradually catch up with the electrons that went out from the gap between the grids earlier, but at lower speeds. Thus, in the space between the grid 3 and the anode 4, the grouping of electrons occurs. The distance by grid 3 and anode 4 is chosen such that fully grouped electrons fall on the latter. This will lead to the fact that the x-ray radiation from the anode will be pulsed, and consequently, the background current of the photoemission will be modulated in time.

Span in the space between the grid 3 and the anode, the electrons ionize the gas molecules. The resulting ions fall on the collector 5, to which a negative potential is applied relative to the cathode. The resulting constant ion current is easily separated from the alternating background current in the collector circuit, which makes it possible to measure lower pressures: The collector is positioned so that x-rays: C ce.i; x) K 2 and 3 do not fall on it.

 PRE D & T Invention

An ionization manometer comprising a thermal cathode, an anode, and an ion collector, characterized in that, in order to expand the lower limit of the measured pressures by grouping electrons emitted by the cathode, two grids are used located near the cathode and connected to a high-frequency voltage source.