Abstract
Isotopic effects on double-excitation resonances in and were observed in photoionization spectra using synchrotron radiation with high monochromator resolution. In , the resonances were found to be shifted to lower energies with respect to by , in good agreement with theoretical expectations based on normal and specific mass shifts. From the experimental data, the resonance parameters , , and of the resonances and were analyzed in detail using a double-convolution fit procedure that considers the different Doppler broadenings of the states in and . In this way, the resolution function of the monochromator could be derived, which can be accounted for in a quantitative way on the basis of the properties of undulator radiation and the optical design of the monochromator.
- Received 8 January 2004
DOI:https://doi.org/10.1103/PhysRevA.69.052703
©2004 American Physical Society