We have made careful absolute measurements of the collisionless multiphoton energy deposition in S${\mathrm{F}}_6$ for C${\mathrm{O}}_2$ laser pulses of varying duration and energy fluence. Likewise, we have also measured the absolute dissociation yields. An experimental plot of yield versus energy deposition shows that the energy distribution function is nearly thermal, becoming somewhat broader than thermal for the longer pulse durations. A "bottlenecking effect" of molecules in the discrete level region is held responsible for this smearing of the population distribution function.

• Received 28 August 1978

DOI:https://doi.org/10.1103/PhysRevA.19.704