| 摘要 |
<p>The ionisation gauge includes a wire anode (20) surrounded by a cylindrical collector (22). There is an electron source (24) between the anode and the collector, the source being a micro-point source. The source is orientated so that electron beam from the cathode travels along a helix path around the anode. Pref. the micro-point electron source (24) includes control electrodes situated in the vicinity of the micro-points, with a control circuit to set the control electrodes' potential, individually and independently, to modify the shape and direction of the electron beam from the source.</p> |
