Scattering of an alkali atomic beam on anti-spin-relaxation-coatings

TL;DR

This study investigates how rubidium atoms scatter off paraffin coatings, revealing that atoms thermalize with the coating and preserve spin polarization, with scattering following Knudsen's law and Maxwellian velocity distributions.

Contribution

It provides detailed experimental data on atomic scattering from paraffin films, showing thermalization and spin preservation, which advances understanding of anti-spin-relaxation coatings.

Findings

Rubidium atoms follow Knudsen's cosine law upon scattering.

Atoms are well thermalized with the paraffin film temperature.

Paraffin coatings preserve atomic spin polarization.

Abstract

We performed scattering experiments using a rubidium (Rb) atomic beam on paraffin films and measured the angular and velocity distributions of scattered atoms. The paraffin films were prepared in various ways and characterized by atomic force microscopy and X-ray diffraction. The films exhibited various roughnesses and crystal structures. The paraffin films preserved the spin polarization of the scattered atoms. The measured angular distributions of all prepared films were consistent with Knudsen's cosine law. The velocity distributions were well fitted by Maxwell's distribution, characterized by a temperature much closer to the film temperature than to the atomic-beam temperature. We therefore concluded that the Rb atoms were well thermalized with the paraffin films via single scattering events.