Performance of Ionization Gauges in Magnetic Field
Tamotsu SUZUKI · Shinku · 1963
The perfomances of ionization gauges (magnetron gauge, B-A Gauge, etc.) in the magnetic field are described. Below 10-3 Torr, the pressure is directly, proportional to the ratio of positive ion current/electrical emission current in the normal triode valves and this principle is used for pressure measurement with an ionization gauge.But the behaviours of the ions and the electrons in gauge valve are much affected by the magnetic field. If the magnetic field is sufficiently higher than critical field B0, most of the electrons fail to reach the anode. The ion current recorded varies with the magnetic field strength and the angle of the direction against the electric field at a constant pressure. Then it upsets the linear relation between ion current and pressure.It is observed that in the magnetic field the gauge electrode is heated locally by electron bombardment for outgassing and melted at the normal power.