Development of crystal extraction studies at the IHEP accelerator
The crystal extraction of 10/sup 7/ proton/s at the BEC experimental facility is described. Detailed computer analysis is made to explain the basic experimental results. Future high-intensity efficient extraction using a short crystal is announced.
On the scaling of electron dechanneling length in bent crystals
We suggest a way to compare the experiments and simulations of electron dechanneling length in bent crystals performed at different energies and different radii. As an example, we compare the SLAC experiment at 3-14 GeV with earlier published predictions of two different Monte Carlo codes for 855 MeV and 50 GeV, and with MAMI experiment at 855 MeV.
Resonant Auger decay study of C1s -> pi* core-excited OCS
The present work aims at characterizing short-lived C1s((-1)) pi*((1)) core-excited states of the OCS molecule based on the analysis of the vibrational fine structure and lineshape profiles of the high-resolution resonant Auger decay spectra recorded at the excitation energies along the C1s -> pi* resonance in the binding energy region 15-19eV. Very different behavior in terms of lineshape and resonant enhancement is observed for the (A) over tilde, (B) over tilde and (C) over tilde final states. This is explained by (1) the variation in the C-O bond lengths for the states involved in the electronic relaxation and (2) different contributions in terms of Mulliken population to the molecular orbitals determining the electronic character of the corresponding states. Since the final-state geometries are known from a number of previous experiments and ab initio calculations, the geometry of the C1s((-1)) pi*((1)) intermediate states can be predicted in analogy with e.g. the N-2, CO2 and N2O molecules. (C) 2009 Elsevier B.V. All rights reserved. (Less)