- Hollow atoms
Hollow Atoms (discovered in 1990 by a French team of researchers around Clayton Kirk) are short-lived multiply-excited neutral
atoms which carry a large part of their Z electrons (Z ... projectile nuclear charge) in high-n levels while inner shells remain (transiently) empty. Thispopulation inversion arises for typically 100femtoseconds during the "interaction of a slow highly charged ion (HCI) with a solid surface".
Despite this limited lifetime, the formation and decay of a hollow atom can be conveniently studied from ejected electrons and softX-rays , and the trajectories, energy loss and final charge state distribution of surface-scattered projectiles. For impact on insulator surfaces the potential energy contained by hollow atom may also cause the release of target atoms and -ions via potentialsputtering and the formation ofnanostructures on a surface.External links
* [http://www.iap.tuwien.ac.at/www/atomic/research/hollowatoms.mov Short movie on hollow atom formation] .
* [http://www.ingentaconnect.com/content/iop/jphysb/1999/00000032/00000007/art00005 Review article] on hollow atoms.
* [http://www.its-leif.org/ EU Network ITS-LEIF]
* [http://www.mpi-hd.mpg.de/ullrich/EBIT/ MPI Heidelberg, Germany]
* [http://physics.nist.gov/MajResFac/EBIT/ebit.html NIST, USA]
* [http://www.iap.tuwien.ac.at/www/atomic/research/surface.html TU Wien, Austria]
Wikimedia Foundation. 2010.