Collisional angular-momentum mixing of highly excited Na(n 2D) states by N2 and CO

Cross sections for the collisional l mixing of Na(n2D) states from n = 5 to 14 by N2 and CO have been measured by time-resolved laser fluorescence and calculated in a two-state approximation by assuming the perturbing gases are spherically symmetric. For both CO and N2 the experimental cross sections rise sharply from n = 5 to n = 10 and remain constant for n > 10. The theoretical calculations overestimate the experimental cross sections by a factor of 3 from n = 10 to 12, but are in good agreement for the smaller n values