This new shutter simply consists of a chopper wheel rotating a mere half‐millimeter away from the skimmer‐shaped diaphragm, which separates the source chamber from the flight tube. The repetition rate can be up to 104pulses per s (width∼60 μs), at an intensity of ∼1019molecules/sr s, whereas existing designs yield ∼1022molecules/sr s, but only at a rate of 1 pulse per 1–10 s. Our design has two main advantages: since there is no gas valve, cumbersome electromechanical devices with large current pulses can be avoided. Second, one is now free to choose the nozzle parameters (e.g.,p0,T0and the throat diameterdn). The beam parameters were determined by means of an electron impact detector featuring a high efficiency ionizer, thus improving the signal‐to‐noise ratio.