Abstract
This chapter discusses velocity-changing collisions (VCC) in the Sm I 570.7 nm (J lower =1 to J upper =0) saturated absorption spectrum. When laser saturation spectra are obtained from vapor cells containing buffer gas, the line shapes are modified by the occurrence of VCC. The VCC are separated phenomenologically into two types: (1) those that produce a large velocity change (strong VCC), giving a broad background pedestal to laser saturation line shapes and (2) those that change the velocity by a small amount (weak VCC), leading to broadening in the region of the Doppler-free peak. Thus, reducing the number of collisions within a chopping cycle reduces the effects of VCC on saturated absorption spectra. This leads to high-quality saturated absorption spectra that allow the effects of strong and weak VCC to be separated and should ultimately allow the effects of phase- and velocity-changing collisions to be distinguished and collision kernels to be determined.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call