A new diode sputter-ion pump employing cathode posts which protrude within the anode cell is described. For suitable post geometry and material, stable pumping of argon at equilibrium speeds in excess of 25% of the nitrogen speed of the pump has been demonstrated. Effects of post geometry and material are explored with respect to optimizing argon speed. Pumping of noble gases is analyzed in terms of the “high-energy neutrals” hypothesis. Memory effects are shown to be reduced due to the enhancement of permanent pumping mechanisms. Field emission from the post results in greatly enhanced starting at extreme high vacuum.