Novel process of isotope separation of silicon by use of IR FEL

We found that silicon isotopes can be effectively enriched when mono-phenyl derivative of SiF4 was used as the working substance. The chemical processes following the multi-photon dissociation of this molecule yield gaseous SiF4 and solid powders of the by-product substances. By tuning the wavenumber of FEL beam at 961 cm−1, the minority isotopes 29Si and 30Si have been successfully enriched in the residual gas of the working substance. Further, 28Si could be enriched to above 98% when irradiated with FEL beam of 934 cm−1.