K-Shell ionization of molecules:



Molecules investigated so far are: CO, N2, C2H2, C2H4, C2H6.
In these studies the two ion fragments are detected in coincidence with the photoelectron from the K-shell or the Auger-electrons.

The electron wave emerging from the K-shell can be used to "ILLUMINATE the Molecule from within"


We have measured the angular distributions of 1s-photoelectrons excited by circularly and linearly polarized light from fixed-in-space CO and N2 molecules, in the vicinity of their shape resonances. (click here)




A compilation of movies showing the angular distribution of K-shell electrons from fixed in space CO and N2:





Angular distribution of Carbon K-Photolectrons emitted by circular polarized light from fixed in space CO. Electron energy 10eV. The molecular axis is given by the blue rod and rotates in time. The photon direction is indicated by the spiral. For more information see Jahnke et al., Circular Dichroism in K-shell Ionization from Fixed-in-Space CO and N2 Molecules, PRL88(2002)073002 (255kb PDF file)


These experiments are performed by the COLTRIMS collaboration at ALS




Angular distribution of photoelectrons from fixed in space CO emitted from the K-shell by linear polarized light.
Upper panel: Oxygen-K-shell, lower panel: Carbon-K-shell. The electron energy is 10eV in both cases. The direction of the molecule is indicated in the figure, the red dot symobilzes the Oxygene. The polarization is horizontal. The full line shows a fit of spherical harmonics up to l=4. For details see Landers et al, Photoelectron Diffraction Mapping: Molecules Illuminated from Within, PRL 87 (2001) 013002 (211kb PDF file)









View the full text of our newest Science article (free):

Ultrafast probing of core hole localization in N2
M. S. Schöffler, J. Titze, N. Petridis, T. Jahnke, K. Cole, L. Ph. H. Schmidt, A. Czasch, D. Akoury, O. Jagutzki, J. B. Williams, N. A. Cherepkov, S. K. Semenov, C. W. McCurdy, T. N. Rescigno, C. L. Cocke, T. Osipov, S. Lee, M. H. Prior, A. Belkacem, A. L. Landers, H. Schmidt-Böcking, Th. Weber, R. Dörner
Science Vol. 320. no. 5878, pp. 920 - 923

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Both links above will lead you to the Science Magazine website.
If you are unable to access the full text, make sure that you reached this page using exactly the following URL: http://www.atom.uni-frankfurt.de/research/atomic/photonmolecule/CO_N2_Kshell/.