A molecular beam is produced by allowing a gas at higher pressure to expand through
a small orifice into a container at lower pressure. The result is a beam of particles
(atoms, free radicals, molecules or ions) moving at approximately equal velocities,
with few collisions occurring between them. In a crossed molecular-beam experiment
a reaction is studied using collimated beams of reactant molecules. For a
bimolecular reaction, beams of the two reactants are caused to impinge on one another, often
at an
angle of 90°. In a beam-gas
scattering experiment a collimated beam is introduced into a gas, and the
scattering patterns are observed.
Source:
PAC, 1996, 68, 149
(A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC
Recommendations 1996))
on page 175
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.
