Sputter ion pump

A sputter ion pump comprising:

• an envelope defining a vacuum chamber therein, the envelope having an aperture extending through an outer wall thereof;
• two anode poles arranged within the envelope;
• a secondary electron emitter located outside of the envelope and corresponding to the aperture;
• and
• a cold cathode electron emitter located on and outside of the outer wall of the envelope generating a flow of electrons towards the secondary electron emitter during normal operation.

A sputter ion pump completely without a magnetic field during normal operation comprising:

• an envelope defining a vacuum chamber therein;
• a cold cathode electron emitter generating a first flow of electrons during normal operation;
• a secondary electron emitter generating a second flow of electrons into the vacuum chamber after being excited by the first flow of electrons during normal operation;
• and
• two anode poles arranged within the envelope and generating a saddle-shaped electrostatic field during normal operation, the travel of the second flow of electrons in the vacuum chamber determined by the saddle-shaped electrostatic field;
• wherein each of the anode poles has a finite curvature.