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Title: Photoelectron and photoionization pumping of XUV lasers by laser-produced plasmas

Miscellaneous ·
OSTI ID:7206746

This thesis represents an experimental and theoretical investigation of several photo-electron and photoionization pumped lasers in the extreme ultraviolet (XUV). In the systems studied, soft x-ray emission from a laser produced plasma is used to excite an ambient atomic or molecular vapor. In photoionization pumped systems, differing photoionization cross sections allow for the preferential ionization of inner shell electrons by soft x-ray photons. The resulting ionic species are either inverted with respect to the ground state of the first ion or are energetically unstable and undergo rapid, selective Auger decay into inverted states in the second ion. Studies of photoionization pumped systems in atomic xenon, krypton, zinc, cesium, lithium and potassium were conducted. In photo-electron pumped systems, an ambient vapor is partially photoionized to create an energetic bath of electrons which then collisionally excites the lasing species. In this way, compact discharges with effective current densities as high as 10{sup 6} amp/cm{sup 2} can be created. Lasers in atomic cesium, molecular hydrogen and molecular nitrogen are believed to be pumped in this manner. Studies of the atomic cesium laser have yielded an extrapolated small signal gain length product as high as exp(85) at a wavelength of 96.9 nm. This laser is also believed to be the first of a new class of lasers in which the upper level of the laser is embedded within the continuum.

Research Organization:
Stanford Univ., CA (United States)
OSTI ID:
7206746
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English