Pressure-shock-controlled pulsed molecular beams

Abstract

A method of controlling the duration of pulses of intense molecular beams is suggested. The idea of the method is the shortening of an initial molecular beam pulse by producing a pressure shock in front of a solid surface through which the beam passes. Experiments on shortening H2, He, SF6, SF6/H2(1/10), and SF6/He(1/10) molecular beam pulses are reported. The parameters of the beams incident on, and transmitted through, the surface are studied. The gas density in the initial beam and in the pressure shock before the surface is estimated. The intensity and duration of shortened molecular pulses are found as a function of the initial intensity, angle of incidence, and the diameter of a hole on the surface through which the beam passes. It is established that the duration of the shortened beam decreases greatly with increasing incident intensity and decreasing hole diameter. It is shown that intense pulsed H2, He, SF6, SF6/H2(1/10), and SF6/He(1/10) molecular beams with a pulse duration of ≤10–15 µs and an extent of ≤1–2 cm can be generated with the method suggested.