Measurements of velocity-changing collision kernels.

摘要: Measurements of velocity-changing collision (VCC) kernels are obtained using velocity-selective optical pumping. This is the first measurement shape an elastic vce kernel over full thermal range velocity changes. Since ground-state collisions studied (5s 1/2 Rb and He, Ne, Ar, Kr, or Xe), very low buffer-gas pressures can be used, therefore pressure broadening (dephasing collisions) does not obscure effects VCC's. The data deconvolved to eliminate natural linewidth then extrapolated with respect determine single-collision limit. For small initial velocities, measured consistent a hard-sphere model for large changes, but differ significantly VCC velocities changes do exhibit this agreement kernel. implies that information about interatomic potential from kernels. We also show inadequacy much-used Keilson-Storer [J. Appl. Math. 10,243 (1952)].