Multiple Tube Collimator for Gas Beams

Abstract

A multiple tube gas collimator is described which consists of a bundle of tubes with 20‐μ radii, made by electrolytic removal of copper wires from the plastic matrix in which they were embedded. Details of construction are given, as well as measurements of the angular distribution of gas flow from the collimator, which are determined with a helium mass spectrometer leak detector. The theory of flow through multiple tube sources is discussed, and a figure of merit giving relative values of beam intensity for fixed collimator area and flow rate is derived. The collimator described in this paper compares favorably with those used by previous workers.