In an ion trap, large amounts of energy are used to rip a great number of electrons out of their atoms, leaving highly charged ions behind. An atom, in which many electrons are located in the outer electron shells while many inner electron states are empty, is called a “Hollow atom”.
“As soon as these hollow atoms enter a solid, for example, when they penetrate a thin foil, their electronic state changes almost instantaneously”, says Richard Wilhelm, a scientist in Prof. Friedrich Aumayr’s team at TU Wien.
The experiment showed that this redistribution is due to an effect, which has been considered to be rather unimportant – the interatomic Coulomb decay: the energy of a single electron is transferred to several other electrons of neighbouring atoms.
The high energy of an electron in the xenon atom is passed on to several electrons in the graphene which can now leave their place and hurtle away – but only with rather low energies.
Such interatomic coulomb decays can also happen when ionizing radiation removes an inner electron from an atom and leaves the atom in a highly excited state.
These new insights about the important role of the interatomic coulomb decay in hollow atoms open up new ways of studying this effect and gaining new insights which are relevant for medicine and biology.