Earl F Worden

US Patent:

54437024, Aug 22, 1995

Filed:

Jun 22, 1993

Appl. No.:

8/079583

Inventors:

Christopher A. Haynam - Pleasanton CA
Earl F. Worden - Diablo CA

International Classification:

B01D 500

US Classification:

20415722

Abstract:

Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of. sup. 167 Er. The hyperfine structure of. sup. 167 Er was used to find two three-step photoionization pathways having a common upper energy level.

US Patent:

59456493, Aug 31, 1999

Filed:

May 27, 1997

Appl. No.:

8/863383

Inventors:

Karl F. Scheibner - Tracy CA
Christopher A. Haynam - Pleasanton CA
Michael A. Johnson - Pleasanton CA
Earl F. Worden - Diablo CA

Assignee:

United States Enrichment Corp. - Bethesda MD

International Classification:

B01D 500

US Classification:

2041572

Abstract:

An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207.