Classical photochemistry with lasers

Recently, there has been interest in performing photochemistry on species adsorbed on a surface. Typically a layer of, for instance, HBr is physisorbed. A small fraction of these molecules are subsequently photolyzed by a laser. In the gas phase, photodissociation processes are best understood using the Franck-Condon principle, and quantum mechanical models (232). However, on a surface, the substrate must be explicitly accounted for. Because of the many-body nature of the process, classical mechanics is a natural choice. The resulting atoms move rapidly over the surface, colliding with both substrate and adsorbate (233-235). 

The classical methods of isotope separation on a large, technical scale, such as thermal diffusion, or gas centrifuge techniques are expensive because they demand costly equipment or consume much energy [14.11], New techniques based on a combination of laser spectroscopy with photochemistry may considerably reduce the costs. Up to now several methods have been proposed and some of them already proved their feasibility in laboratory experiments. The extension to an industrial scale, however, demands still more efforts and many improvements. ... 

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