Cluster beam production by a slit-throat nozzle

A nozzle with a slit-throat, capable of producing a cluster beam of a high total flux while keeping the cluster size constant, was constructed. The basic idea underlying this new type of nozzle is that a slit-throat nozzle is equivalent to a linear array of axisymmetric nozzles of diameter qual to the throat width. A comparison between experimental results with both this nozzle and a trumpet-shaped nozzle showed that the cluster size produced with the same nozzle-source parameters, such as temperature and pressure, is limited by the width of the slit-throat and that the total flux increases in proportion to its length. A comparison between the experimental results and calculations based on the classical condensation theory was also performed. (author)