MICROWAVE INTERFEROMETRIC MEASUREMENTS OF ELECTRON DENSITY IN LASING ALKALI-RARE GAS MIXTURES

This proposed Phase II Small Business Technology Transfer (STTR) program will measure absolute electron densities in laser-pumped Rb/rare gas plasmas with a microwave interferometer. Although several models of the collisional chemistry of Diode-Pumped Atomic Lasers (DPALs) exist, benchmarking such models with experimental results has been hampered by the absence of measurements of the electron density, in particular. The measurement of the electron density and other parameters such as ion recombination lifetimes is also essential for optimizing laser performance. Accordingly, a ~9 GHz microwave interferometer will be constructed, calibrated, and benchmarked with at least two well-characterized ionization sources, including a pulsed 254 nm lamp. Time-resolved measurements of ne will allow for the dominant ions in the Rb/He plasma to be identified, and the ion-electron recombination coefficients to be measured. Approved for Public Release | 24-MDA-11673 (8 Jan 24)