Multi-ionization of atoms and molecules exposed to X-FEL radiation
by
Magdalena Kaminska(Atomic Physics Department)
→
Europe/Stockholm
FA 31
FA 31
Description
An innovative approach to electron spectroscopy has very recently become
possible with the advent of X–ray free electron lasers (X-FELs) due to
their unique properties of unprecedentedly high peak intensity and
ultra-short pulse duration in this spectral region. Utilizing such
experimental conditions in combination with a versatile time-of-flight
magnetic bottle electron spectrometer of high collection-detection
efficiency and the correlation analysis method of covariance mapping [1]
allows identification and in-depth examination of complex multi-photon
ionization processes in atoms and molecules. In particular, double core
hole (DCH) states, where the two vacancies can be created efficiently at
X-FELs upon sequential two-photon absorption either on the same atomic site
(single-site DCH) or on two different atomic sites of the molecular species
(two-site DCH) before the competing Auger decay occurs, are subject of
great interest, since the two-site DCH states are expected to show a higher
chemical sensitivity compared to single core hole states [2]. Using the
Linac Coherent Laser Source (LCLS) X-FEL at Stanford, USA we investigated
the formation of DCH states in neon atoms [3] and 4-aminophenol in relation
to other competing multi-ionization processes.
[1] L.J. Frasinski et al. 1989 Science 246 1029
[2] L.S. Cederbaum et al. 1986 J. Chem. Phys. 85 6513
[3] V. Zhaunerchyk et al. 2013 J. Phys. B: At. Mol. Opt. Phys. 46 164034
