Time resolved gain/loss studies under low and high power loading for the XeF C-A transition
Authors: Sze Robert C., Sentis Marc, Vannini Matteo
Autors Affiliation: Los Alamos Natl Lab, Los Alamos, United States
Abstract: The behaviour of gain versus peak power deposition and the gain-length product versus total energy deposited are measured for devices with power deposition levels from 1 to 13 MW/cm3 under a variety of gas mixtures. The temporal correlation between the power deposition and gain shows that both the flourescent and the gain occur after the power deposition has concluded for excitation pulses in the range of 10-30ns. We find that both B-X and C-A flourescent takes place in the afterglow and their temporal shapes are similar. This indicates that the C and B states are tightly coupled. This tight coupling has two detrimental consequences for C-state lasing. First is that the population of the B and C states are approximately equal rather than 90% in the C state believed to exist for short pulse electron beam excitation. We believe this close coupling is due to the presence of electric fields in the afterglow which keep the electron temperature relatively hot. The relative populations of the B and C states are determined by a Boltzman distribution governed by electron temperature and their relative energy separation. Second is that with the C state lifetime approximatley the same as the B state lifetime the C-A saturation intensity is very high and efficient energy extraction is substantially more difficult.
KeyWords: Chlorine Compounds; Electric Field Effects; Electrons; Laser Pulses; Xenon, Boltzmann Distribution; C-A Transition; C-State Lasing; Electron Temperature; Time Resolved Gain/Loss Studies, Lasers, ExcimerDOI: 10.1117/12.20613