Molecular Beam Formation by Long Parallel Tubes

Abstract

The characteristics of molecular beams formed by sources consisting of long tube arrays are measured for several sources. The peak beam intensity and the beam width are calculated when collisions in the source are taken into account under the assumption that a limited region of Knudsen type flow occurs near the low‐pressure end of the source. The peak beam intensity and the beam width are calculated to vary as the square root of the total flow rate for source pressures giving useful directivity, in good agreement with the observations. Considerations in the design of sources are discussed.