Hg 5d and 6s: Multichannel quantum-defect analysis of experimental data

Schäfers F, Heckenkamp C, Müller M, Radojevic V, Heinzmann U. Hg 5d and 6s: Multichannel quantum-defect analysis of experimental data. Physical Review, A: Atomic, Molecular and Optical Physics. 1990;42(5):2603-2613.Experimental spin-polarization data for the Hg 6s Cooper minimum and dipole-transition amplitudes and phase-shift differences for photoionization of the Hg 5d and 6s shells (eight channels) in the photon-energy region from the 2D3/2 threshold up to 35 eV (kinetic energies from 0 to 20 eV) are presented and compared with new relativistic random-phase approximation calculations. The data were evaluated from an experimental data set, quantum mechanically complete, consisting of cross-section and photoelectron spin-polarization data. For the 5d subshells the results show strong interchannel coupling between the outgoing p and f continuum channels. The results for Hg 6s could be used for an independent determination of the photoelectron angular distribution parameter [Beta] in the Cooper-minimum region. This region is shown to be perturbed by numerous two-electron excitations, which might be a possible explanation for the controversy on its location

A high flux normal incidence monochromator for circularly polarized synchrotron radiation

Eyers A, Heckenkamp C, Schäfers F, Schönhense G, Heinzmann U. A high flux normal incidence monochromator for circularly polarized synchrotron radiation. Nuclear Instruments and Methods in Physics Research. 1983;208(1-3):303-305.Design and performance of a 6.3 m normal incidence UHV-monochromator (see fig. 1) of the Gillieson type for synchrotron radiation are described. The monochromator will be used for simultaneously spin polarization and emission angle-resolved photoelectron spectroscopy; it combines a high photon flux and a high degree of circular polarization of the monochromatized radiation with a moderate resolution

A rotatable electron spectrometer system for spin- and angle-resolved photoemission experiments with circularly polarized synchrotron radiation

Heckenkamp C, Eyers A, Schäfers F, Schönhense G, Heinzmann U. A rotatable electron spectrometer system for spin- and angle-resolved photoemission experiments with circularly polarized synchrotron radiation. Nuclear Instruments and Methods in Physics Research A: Accelerators, Spectrometers, Detectors and Associated Equipment. 1986;246(1-3):500-503.An electron-optical system is described which has been especially designed for spin- and angle-resolved photoelectron spectroscopy with circularly polarized synchrotron radiation. One hv- and one uhv-type of this system (for studies at atoms/molecules and solids/adsorbates, respectively) are in operation at the storage ring BESSY. The system employs, thus, a light source and an electron spin detector (high energy Mott detector) both fixed in space. This is realized by a rotatable electron spectrometer and a 90° deflector by which the electron beam is directed along the axis of rotation of the spectrometer, independent of the emission angle chosen

Angular Dependence of the Spin-Polarization Transfer from Circularly Polarized Synchrotron Radiation onto Photoelectrons from Atomic Xe 5p6

Heckenkamp C, Schäfers F, Schönhense G, Heinzmann U. Angular Dependence of the Spin-Polarization Transfer from Circularly Polarized Synchrotron Radiation onto Photoelectrons from Atomic Xe 5p6. Physical review letters. 1984;52(6):421-424.The photoelectron emission from atomic xenon has been simultaneously resolved with respect to photon energy, photon (circular) polarization, photoelectron emission angle, electron kinetic energy, and spin-polarization components by use of synchrotron radiation of wavelengths between 48 and 90 nm from the new dedicated electron storage ring BESSY. The angular dependence of the spin polarization and the energy dependence of the dynamical spin parameters experimentally obtained show good agreement with theoretical predictions

First angle-resolved measurements of spin polarization transfer (Fano effect) from circularly polarized VUV radiation onto photoelectrons at rare gas atoms

Heckenkamp C, Schäfers F, Schönhense G, Heinzmann U. First angle-resolved measurements of spin polarization transfer (Fano effect) from circularly polarized VUV radiation onto photoelectrons at rare gas atoms. Annals of the Israel Physical Society. 1983;6:115

High-flux normal incidence monochromator for circularly polarized synchrotron radiation

Schäfers F, Peatman W, Eyers A, Heckenkamp C, Schönhense G, Heinzmann U. High-flux normal incidence monochromator for circularly polarized synchrotron radiation. Review of Scientific Instruments. 1986;57(6):1032-1041

Energy dependence of the electron spin polarisation parameters for Hg 5d photoionisation with circularly polarised light

Schäfers F, Heckenkamp C, Schönhense G, Heinzmann U. Energy dependence of the electron spin polarisation parameters for Hg 5d photoionisation with circularly polarised light. Journal of Physics B: Atomic, Molecular and Optical Physics. 1988;21(5):769-774.Circularly polarised VUV radiation from the storage ring BESSY was used to measure all three spin polarisation parameters of photoelectrons from the Hg 5d shell in the photon energy range from threshold to approximately 35 eV. The experimental results are compared with theoretical calculations in the relativistic and non-relativistic random-phase-approximation scheme (RRPA and RPAE respectively) and Dirac-Slater (DS) calculations. A discussion of the influence of relativistic and potential barrier effects on the experimental data is given

A laser-generated plasma as a source of VUV continuum radiation for photoelectronic spectroscopy

Heckenkamp C, Heinzmann U, Schönhense G, Burgess DD, Thorne AP, Wheaton JEG. A laser-generated plasma as a source of VUV continuum radiation for photoelectronic spectroscopy. Journal of Physics D: Applied Physics. 1981;14(12):L203-L206.The feasibility of using laser-generated plasmas as VUV continuum sources for photoelectron spectroscopy has been demonstrated by measuring the spectral intensity distribution of the VUV continuum in the wavelength region from 79 to 43 nm by energy analysis of the photoelectrons ejected from argon atoms. The maximum photon flux obtained after reflection at a gold-coated spherical mirror was of the order of 10(11) photons nm(-1) per pulse at 50 nm for a laser energy of 830 mJ. The results show a shift of the emission maximum to lower wavelengths with increasing laser energy