ISSN:
1432-0649
Keywords:
42.70Fh
;
42.60Da
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The theory of many-electron atoms and ions and their interaction with XUV radiation is one of the fundamental aspects of X-ray laser physics. The topic of this paper is the theory of optical constants of many-electron atoms in the XUV which define the dielectric susceptibility of materials in this wavelength range. We use the statistical description of atomic electrons and, as a starting point, develop the rigorous theory of the dynamical response of a Thomas-Fermi atom. The equations obtained are used with proper boundary conditions to find the dynamical polarizability and photoabsorption of many-electron atoms. The results are employed for an analysis of existing experimental data on optical constants of Ar and Si. A procedure is suggested to include into the theory the effects of atomic electron shell structure. This leads to more reasonable results and better agreement with experiment. In particular, the effect of the Cooper minimum in the atomic photoionization cross-section can be described. As the existing experimental data on optical constants of materials in XUV are not complete and systematic, we use the theoretical photoionization cross-sections and polarizabilities in constructing and predicting of parameters of X-ray optical systems. Some results on reflectivity of “whispering gallery” mirrors in the 150〈λ〈500 Å wavelength range are presented.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00357286
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