| 摘要 |
<p>Ionisation pressure gauge uses combination of electric field between electrodes and applied magnetic field to lengthen the ionising trajectory of rays from beta-emitter coating first electrode to give amplified measurement at low pressure. In one form, the first electrode is a rod coaxial with a cylindrical second electrode and on the axis of a cylindrical chamber. The magnetic field, in the form of a magnetic bottle, is produced by pole pieces at the bases of the cylinders. In an alternative form, the first electrode is a spiral ribbon within a cylindrical second electrode and cylindrical chamber, the magnetic pole pieces being at the sides.</p> |
