Pulsed mass spectrometer leak valve with controlled energy closure

摘要

The closure of a leak valve in a pulsed mass spectrometer is controlled to thereby substantially extend the life of the valve. An actuator responds to a pulse to open the valve. At the end of the open period the element that closes the valve seat is allowed to travel a substantial distance from the open position of the element to the nearly closed position of the element. The pulse amplitude is then controlled so that the time for the element to travel the remaining distance to valve seat closure is extended in time. The pulse amplitude can also be controlled so that the valve will never close except under fault conditions where power is lost or in a non-operating mode.