Multinozzle gas-dynamic molecular-beam source

Abstract

The results of an experimental investigation of a multinozzle gas-dynamic molecular-beam source, in which the working material is introduced directly into a supersonic jet of a buffer gas, are presented. The source is designed to create slow cold beams of atoms and molecules. Time-of-flight profiles of the beams of the N2 buffer gas and the working material SF6 formed by a source with six nozzles are presented. The measured parameters of the flow field of the buffer gas are compared with the results of calculations for an axisymmetric nozzle with an inner body having an annular critical cross section. The results obtained show that multinozzle designs can be used, in principle, in molecular-beam sources instead of axisymmetric nozzles with an inner body. This permits relaxation of the requirements placed on the accuracy needed in fabricating such sources, reduction of the buffer gas flow rate, and the employment of fairly simple schemes for recycling the buffer gas.