Saturation effects

Prior to operating an IGP for the first time, the cathodes are unsaturated and the cathode material has not been combined with gases. A new ion pump actually pumps up to twice the steady state pumping speed. After several hours of operation (at typical starting pressures), with a constant gas load, the pump achieves a steady state wherein the amount of gas being pumped is equal to the amount of gas being released from the pump walls. If the primary gas component is altered, this effect will again be noticed until the pump saturates with the new species.