Measurements of velocity-changing collision kernels

Kurt Gibble, A. Gallagher

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement of the shape of an elastic VCC kernel over the full thermal range of velocity changes. Since ground-state collisions are studied (5s1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, and therefore pressure broadening (dephasing collisions) does not obscure the effects of VCC. The data are deconvolved to eliminate the effects of the natural linewidth and are then extrapolated with respect to buffer-gas pressure to determine the single-collision limit. For small initial velocities, the measured kernels are consistent with a hard-sphere model for large velocity changes, but differ significantly for small velocity changes. The measured VCC kernels for large initial velocities and large velocity changes do not exhibit this agreement with the hard-sphere kernel. This implies that information about the inter- atomic potential can be obtained from a measurement of VCC kernels. We also show the inadequacy of the much-used Keilson-Storer kernel [J. Appl. Math. 10, 243 (1952)].

Original languageEnglish (US)
Pages (from-to)1366-1380
Number of pages15
JournalPhysical Review A
Volume43
Issue number3
DOIs
StatePublished - Jan 1 1991

Fingerprint

collisions
gas pressure
buffers
pressure broadening
optical pumping
ground state

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Cite this

Gibble, Kurt ; Gallagher, A. / Measurements of velocity-changing collision kernels. In: Physical Review A. 1991 ; Vol. 43, No. 3. pp. 1366-1380.
@article{b3524e79818247868c9aba5df85957f8,
title = "Measurements of velocity-changing collision kernels",
abstract = "Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement of the shape of an elastic VCC kernel over the full thermal range of velocity changes. Since ground-state collisions are studied (5s1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, and therefore pressure broadening (dephasing collisions) does not obscure the effects of VCC. The data are deconvolved to eliminate the effects of the natural linewidth and are then extrapolated with respect to buffer-gas pressure to determine the single-collision limit. For small initial velocities, the measured kernels are consistent with a hard-sphere model for large velocity changes, but differ significantly for small velocity changes. The measured VCC kernels for large initial velocities and large velocity changes do not exhibit this agreement with the hard-sphere kernel. This implies that information about the inter- atomic potential can be obtained from a measurement of VCC kernels. We also show the inadequacy of the much-used Keilson-Storer kernel [J. Appl. Math. 10, 243 (1952)].",
author = "Kurt Gibble and A. Gallagher",
year = "1991",
month = "1",
day = "1",
doi = "10.1103/PhysRevA.43.1366",
language = "English (US)",
volume = "43",
pages = "1366--1380",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "3",

}

Measurements of velocity-changing collision kernels. / Gibble, Kurt; Gallagher, A.

In: Physical Review A, Vol. 43, No. 3, 01.01.1991, p. 1366-1380.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Measurements of velocity-changing collision kernels

AU - Gibble, Kurt

AU - Gallagher, A.

PY - 1991/1/1

Y1 - 1991/1/1

N2 - Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement of the shape of an elastic VCC kernel over the full thermal range of velocity changes. Since ground-state collisions are studied (5s1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, and therefore pressure broadening (dephasing collisions) does not obscure the effects of VCC. The data are deconvolved to eliminate the effects of the natural linewidth and are then extrapolated with respect to buffer-gas pressure to determine the single-collision limit. For small initial velocities, the measured kernels are consistent with a hard-sphere model for large velocity changes, but differ significantly for small velocity changes. The measured VCC kernels for large initial velocities and large velocity changes do not exhibit this agreement with the hard-sphere kernel. This implies that information about the inter- atomic potential can be obtained from a measurement of VCC kernels. We also show the inadequacy of the much-used Keilson-Storer kernel [J. Appl. Math. 10, 243 (1952)].

AB - Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement of the shape of an elastic VCC kernel over the full thermal range of velocity changes. Since ground-state collisions are studied (5s1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, and therefore pressure broadening (dephasing collisions) does not obscure the effects of VCC. The data are deconvolved to eliminate the effects of the natural linewidth and are then extrapolated with respect to buffer-gas pressure to determine the single-collision limit. For small initial velocities, the measured kernels are consistent with a hard-sphere model for large velocity changes, but differ significantly for small velocity changes. The measured VCC kernels for large initial velocities and large velocity changes do not exhibit this agreement with the hard-sphere kernel. This implies that information about the inter- atomic potential can be obtained from a measurement of VCC kernels. We also show the inadequacy of the much-used Keilson-Storer kernel [J. Appl. Math. 10, 243 (1952)].

UR - http://www.scopus.com/inward/record.url?scp=0039910961&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0039910961&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.43.1366

DO - 10.1103/PhysRevA.43.1366

M3 - Article

AN - SCOPUS:0039910961

VL - 43

SP - 1366

EP - 1380

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 3

ER -