Velocity distribution function of spontaneously evaporating atoms

Sergiu Busuioc, Livio Gibelli, Duncan A. Lockerby, James E. Sprittles

Research output: Contribution to journalArticlepeer-review


Numerical solutions of the Enskog-Vlasov equation are used to determine the velocity distribution function of atoms spontaneously evaporating into near-vacuum conditions. It is found that an accurate approximation is provided by a half-Maxwellian including a drift velocity combined with different characteristic temperatures for the velocity components normal and parallel to the liquid-vapor interface. The drift velocity and the temperature anisotropy reduce as the liquid bulk temperature decreases but persist for relatively low temperatures corresponding to a vapor behavior which is only slightly nonideal. Deviations from the undrifted isotropic half-Maxwellian are shown to be consequences of collisions in the liquid-vapor interface which preferentially backscatter atoms with lower normal-velocity component.
Original languageEnglish
Article number103401
JournalPhysical Review Fluids
Issue number10
Early online date12 Oct 2020
Publication statusE-pub ahead of print - 12 Oct 2020

Fingerprint Dive into the research topics of 'Velocity distribution function of spontaneously evaporating atoms'. Together they form a unique fingerprint.

Cite this