Lasers vaporization, refractory atom

Recently, a similar approach has beep-used to investigate van der Waals complexes of Al( P) with Ar and In( P) with Ar, Kr, and Xe." Laser vaporization of the refractory atom followed by supersonic expansion in rare gas carrier was to sinthesize van der Waals complexes. Gardner and Lester" then used mass resolved resonance-enhanced multiphoton ionization (REMPI) for obtaining rovibration excitation spectra... 

The spectrum of uranium metal vapor is complex with over 3x10 lines in the visible region. Still, many of these are very sharp and show sufficient isotope separation to permit selective excitation. The basic idea of AVLIS is to irradiate uranium metal vapor at a concentration around 10 atoms cm (higher concentrations destroy the separation due to collisional broadening). Uranium is a refractory metal, and vaporization is difficult. Electron bombardment under high vacuum yields an atomic beam that passes through the laser radiation field where U is selectively excited. 

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