Darmstadt 2008 – scientific programme

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A: Fachverband Atomphysik

A 25: Posters: Precision spectroscopy of atoms and ions

A 25.9: Poster

Thursday, March 13, 2008, 16:30–18:30, Poster C3

Soft X-ray spectroscopy on highly charged ions — •Thomas Baumann, Sascha Epp, Martin Simon, José R. Crespo López-Urrutia, and Joachim Ullrich — Max-Planck Institut für Kernphysik, Heidelberg, Germany

A flat-field grazing incidence grating spectrometer has been used to study the emission spectra of highly charged ions (HCI) in the soft X-ray region, covering a spectral range from 5 to 40 nm. HCIs were produced and confined at the FLASH-EBIT (Electron Beam Ion Trap), which is capable of preparing ions of essentially any element up to charge states with ionisation energies from 100 eV to 50 keV. In order to improve the spectral resolution beyond our current limits, a new soft X-ray spectrometer has been designed and assembled. It enhances the linear dispersion (and thus the resolution) by a factor of three. These two instruments are ideal not only for spectroscopic diagnostics requiring wide spectral coverage but also for precision wavelength measurements. As an example, measurements at excitation energies between 100 eV and 400 eV covering Xe and Fe in low charge states (XeIX to XeXV, FeVII to FeXV) are presented. The Xe data are particularly relevant for the next generation of semiconductor microlithography devices.