Ionization gauge

A method of measuring a gas pressure from gas molecules and atoms, comprising the steps of:

• producing electrons at an electron source;
• transmitting the electrons through an electron window, the electron window isolating the electron source from the gas molecules;
• decelerating the electrons using a deceleration electrode between the electron window and the collector electrode;
• and
• collecting ions formed by impact between the decelerated electrons and the gas molecules and atoms on a collector electrode.

An ionization gauge, comprising:

• means for producing electrons;
• means for collecting ions formed by impact between electrons from an electron source and gas molecules;
• means for isolating the means for producing electrons from the gas molecules;
• and
• means for decelerating the electrons using a deceleration electrode disposed between the means for isolating electrons and the means for collecting ions.