Molecular-Beam Sources Fabricated from Multichannel Arrays. II. Effect of Source Size and Alignment

Abstract

The effect of the gross diameter of a molecular‐beam source and its alignment in the system upon source efficiency have been investigated analytically. If the diameter of the source approaches that of the collimating orifice used to form the molecular beam, the efficiency may be reduced by 50% or more. Reasonable displacement and tilt misalignments can be tolerated before source efficiency is substantially reduced. The effects of size and misalignment are more critical for multichannel sources with highly peaked angular distributions than for cosine sources.