Trends in autoionization of Rydberg states converging to the 4s threshold in the Kr-Rb⁺-Sr²⁺ isoelectonic sequence: theory and experiment

We have measured the photoabsorption spectra of the Kr-like ions Rb+ and Sr2+ at photon energies corresponding to the excitation of 4s-np resonances using, the dual laser plasma photoabsorption technique. Dramatic changes in the line profiles, with increasing ionization and also proceeding along the Rydberg series of each ion, are observed and explained by the trends in 4s-transition amplitudes computed within a framework of configuration-interaction Pauli-Fock calculations. Total photoionization cross sections show very good agreement with relative absorption data extracted from the measured spectra

Soft X-ray fluorescence study of the quasi-one dimensional Heisenberg antiferromagnet tetraphenylverdazyl

金沢大学理学部Soft-x-ray fluorescence measurements have been performed on a single crystal of the organic antiferromagnet 2,4,6-triphenylverdazyl. Resonant and nonresonant C Ka and N Ka (2p!1s transition! x-ray emission spectra ~XES! were measured and compared with x-ray photoelectron valence band spectra and deMon density-functional theory calculations. It is shown that intramolecular interactions are much stronger than intermolecular ones and give the main contribution to the formation of C 2p density of states. We present evidence of a delocalization of unpaired N 2p electrons over the verdazyl ring. The excitation energy dependence of C Ka and N Ka XES observed below the C 1s and N 1s thresholds, respectively, is discussed in terms of symmetry selective resonant inelastic x-ray scattering

NIST Metrology for Soft X-Ray Multilayer Optics

As part of its commitment to support the microelectronics industry, NIST has begun a metrology program in die area of normal incidence, soft x-ray optical systems for use in both basic and applied research. At present, this program consists of dual efforts in the fields of surface figure and surface finish characterization and optical component soft x-ray reflectometry. In this paper, we will focus our discussion on the work performed at NIST using the existing soft x-ray reflectometer, the design characteristics of a new reflectometer which will replace the present instrument, and our plans to build an optical characterization facility based on a real time, two dimensional, soft x-ray imaging system with an ultimate resolution of a few tens of nanometers.</jats:p