Experiments on Microwave Scattering of REMPI in Argon, Xenon and Nitric Oxide

Experiments on microwave scattering from resonance enhanced multiphoton ionization (RADAR REMPI) are presented for argon (3+1 REMPI), xenon (2+1 REMPI) and nitric oxide (1+1 REMPI) to demonstrate its capabilities for nonintrusive diagnostics. The time evolution of the microwave scattering from 3+1 REMPI in argon with different frequency tripled Ti:sapphire laser pulse energies at different pressures is given and compared to results from a plasma dynamic model. A polarized, narrowband laser beam is then used to record a three photon resonant REMPI spectrum of argon. For xenon and nitric oxide, mixing upshifted, frequency doubled dye laser was used to demonstrate the Radar REMPI process. The xenon ionization spectra at higher pressures are observed to have asymmetric peaks. The low pressure xenon spectrum was used to calibrate the laser wavelength and linewidth for the nitric oxide measurement. The nitric oxide spectrum obtained matches the REMPI literature.