V. Saile

Rydberg series in the absorption spectra of H2O and D2O in the vacuum ultraviolet

Abstract The photoabsorption cross section of molecular H2O and D2O has been determined in the range from hν = 10eV to 20 eV with 0.03 A resolution. A refined analysis of the Rydberg series including the rotational line shapes of several bands to locate the band origins and a comparison with recent ab initio calculations is given. In the region of continuous absorption we have assigned a p-type and an s-type Rydberg series leading to the 2A1 and the 2B2 state respectively with quantum defects δ ≈ 0.75 and δ ≈ 1.36.

High resolution absorption spectrum of nitrogen in the vacuum ultraviolet

Abstract The photoabsorption cross section of molecular N 2 has been determined in the range from 10- 35 eV utilizing the continuum of synchrotron radiation from the DORIS storage ring, a 3m normal incidence monochromator of 0.03Aresolution and photoelectrical recording. New detailed features are observed which make possible a refined analysis of the valence-Rydberg interaction of the b 1 Π u –c 1 Π u , b′ 1 Σ + u –c′ 1 Σ + u states as well as an improved analysis of Rydberg series leading to the X 2 Σ + g , the A 2 Π u , the B 2 Σ + u and the C 2 Σ + u states of the N + 2 ion.

High resolution monochromator for the VUV radiation from the DORIS storage ring

The unique properties of the DORIS storage ring at DESY as a synchrotron radiation source are exploited for high resolution spectroscopy in the vacuum ultraviolet. We describe a new experimental set up with a 3-m normal incidence monochromator for wavelengths between 3000 A and 300 A (4 </= ?w </= 40 eV) using a vertical dispersion plane. The storage ring provides a light flux intense and stable enough for rapid photoelectrical scanning of the spectra with a resolution of 0.03 A in first order.

Exciton dynamics in solid neon

In this paper we report the results of an experimental study of the photoelectric yield of pure and doped solid Ne in the extreme ultraviolet (h/ω=8–30 eV) by use of synchrotron radiation from the DESY synchrotron. Results for the range of impurity excitations, exciton states, and interband transitions were obtained for Xe in Ne, Kr in Ne, and Ar in Ne. The photoemission data where utilized to extract new information concerning (a) energetics, (b) nonradiative relaxation phenomena, and (c) exciton dynamics in solid Ne. Concerning (a) a definite value for the electron affinity V0 in solid Ne was established experimentally. Concerning (b) we were able to show that the n=2 (1/2) exciton decays in an Auger‐type process into an ionized impurity in the (3/2) state and a free electron on a time scale τ (Auger) ?10−13 sec, which is comparable or even shorter than the n=2→n=1 nonradiative relaxation process. Concerning (c) the analysis of the energy dependent photoemission line shape at different film thicknesses ...

Fine structure in optical transitions from 3d and 4d core levels to the lower conduction band in Ga-V and In-V compounds

We investigate fine structure in energy derivative reflectance (EDR) spectra near 20–21 eV in GaP, GaAs, and GaSb, and near 18–20 eV in InP, InAs, and InSb. Derived energy values for Xc1 thresholds in GaP and GaSb, and Lc1 and Xc1 thresholds in GaAs, agree well with previous Schottky barrier electroreflectance (ER) results. L-X structure splittings in EDR spectra of InAs and InSb, for which Schottky barrier ER measurements cannot be performed, are 0.29 and 0.44 eV, respectively. Estimates of expected locations of these structures, based on XPS and absorption data and band structure calculations, indicate energy deficits of 0.2 eV for In4d-Lc1 and 0.5 eV for In4d-Xc1 transitions, respectively.

K+3P-core excitons in potassium halides studied at low temperatures with high resolution

Abstract Reflection spectra of KF, KCl, KBr and KI single crystals have been measured at photon energies of approximately 20 eV with a bandwidth of 10 meV using synchrotron radiation in order to study fine structure and temperature dependence of the excitonic transitions associated with the K+3p core level. The crystals were cleaved under ultrahigh vacuum and cooled down to 20 K. Information on energy positions, halfwidths and line shapes for the K+3p-core excitons and their temperature dependence has been obtained. A new exciton predicted by the ligand field model was observed. For KI we evaluate an electron-hole exchange energy of only 30 (± 7) meV.

Fine structure in the VUV absorption spectrum of neopentane at 16 eV

The photoabsorption of neopentane (C(CH3)4) has been measured for photon energies from 10 to 30 eV with synchrotron radiation. Sharp absorption bands are observed around 16 eV on top of a strong continuum. These can be grouped into a p-like Rydberg series with accompanying vibrational sub-bands. The nature of the Rydberg states is discussed.

Photoemission from solid neon

Abstract The photoelectric yield of solid Ne has been studied for photon energies between 15 and 30 eV. Strong photoemission from the valence band sets in at 21.4 ± 0.1 eV. The value of the electron affinity derived from this is discussed. A surface resonance for Ne atoms adsorbed on gold is observed at 17.1 eV.

Optical excitation of the Rb+ 4p-level in rubidium halides at 8 K☆

Abstract In the 15–19 eV range new spectral features have been resolved in the reflection spectra of RbCl, RbBr, and RbI single crystals. They are not entirely consistent with results of a recently proposed ligand field model for the Rb+4p- excitons.

A comparison of experimental and theoretical photoelectron energy distribution curves for solid argon and krypton

Abstract We present a comparison of recent experimental data and recent theoretical calculations of the photoelectron energy distribution curves for solid argon and krypton. These comparisons are significant in that they support the idea that the valence states of the solid rare gases are band like and of non-negligible width (Ar is about 1.5 eV wide and Kr is about 2 eV wide). Furthermore, in order to obtain reasonable agreement between theory and experiment, the the calculations needed were selfconsistent Hartree-Fock in nature and were corrected for both long range correlation effects (polarization) and short range effects (relaxation).