Anisotropy of Resonant Inelastic X-Ray Scattering at the K Edge of Si:Theoretical Analysis

We investigate theoretically the resonant inelastic x-ray scattering (RIXS) at the $K$ edge of Si on the basis of an ab initio calculation. We calculate the RIXS spectra with systematically varying transfered-momenta, incident-photon energy and incident-photon polarization. We confirm the anisotropy of the experimental spectra by Y. Ma {\it et al}. (Phys. Rev. Lett. 74, 478 (1995)), providing a quantitative explanation of the spectra.Comment: 18 pages, 11 figure

Ion time-of-flight spectroscopy: krypton charge-state spectra as a function of photon excitation energy near the K edge

In this experiment, we have recorded the charge state distribution resulting from atomic rearrangement following the creation of the inner shell vacancies in krypton atoms. Intense, highly collimated, monochromatic and tunable x-ray radiation available at the CHESS synchrotron radiation facility at Cornell was used to photoionize krypton atoms in a gas jet target, and a time-of-flight spectrometer was used to record the ions in different charge states formed after photoionization. Charge state spectra were recorded at below, at the peak in the K edge and above the edge. Below the edge, charge states +4 to +7 were observed with appreciable intensity, while at, and above the edge, the charge states ranged from +4 to +10

Studies of ion beam-photon interactions at the National Synchrotron Light Source

To date, synchrotron radiation has been used for atomic physics experiments with gas or vapor targets. Experiments with crossed or merged ion and photon beams are made possible by the advent of high-brightness synchrotrons such as the National Synchrotron Light Source. Some types of experimental programs which can now be pursued are considered. Design parameters for a proposed ion-photon beam apparatus are discussed

Non-normalization behavior of crystal glitches in an EXAFS spectrum: Is it possible to remove crystal glitches?

The existence of crystal glitches in EXAFS data is widely recognized and is usually dealt with during data analysis. However, in many cases, especially as samples become more dilute, the disruption of the data can become irretrievable. The advent of new, high output, double-crystal x-ray monochromators has made it necessary to investigate the cause of such glitches with a view to reducing them in the original data. The occurrence of multiple reflections within the crystal gives rise to the glitches seen in EXAFS data when the two crystals in a double-crystal monochromator are not accurately aligned. The results of a simple alignment of such a double-crystal monochromator are presented and show a reduction of the glitches in the recorded data. A purpose-built monochromator for further investigation of this problem is described and some results towards the further reduction of glitches are presented. It is shown that the removal of crystal glitches from EXAFS data is possibl