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Press Release
Slow Electrons are "killing" Ozone
- Outstanding new discoveries in ion
physics
Innsbruck/Vienna (Austrian Science Fund) - Tilmann Märk from the
Institute of Ion Physics at the University of Innsbruck and his team have,
with the support of the Austrian Science Fund, developed unique methods
and equipment to examine the interaction of electrons with atoms, molecules
and clusters. And their research has been successful - they have made
a number of discoveries, including a new ozone destruction process, and
they have clearly established the binding energy of the "buckyball",
C60 , which has long since been the subject of international
research.
The destruction of the ozone in the earth's atmosphere has many different
causes, many of which are unknown. Tilmann Märk and his team, in
cooperation with University College London, have identified a phenomenon
which was hitherto considered impossible, but which basically constitutes
another ozone destruction process.
"We have proved what was previously considered impossible: slow,
thermal electrons are taken up by the ozone. This happens with great frequency
and has a detrimental effect on the atmosphere, since this destroys the
ozone," explains Märk.
Since there are a great number of these slow electrons in the ionosphere,
it is clear that the many ozone models must be recalculated in light of
these results and the simulations must be re-worked.
The binding energy of the "buckyball"
A further highlight amongst Märk's results relates to the well-known
football-shaped "buckyball" C60, which is characterised
by its particular stability. In cooperation with the University of Jerusalem,
Märk has revealed the secret of this binding energy. "Unusually
for a "football", we bombarded the C60 molecule with
electrons, thereby attempting to break a C2 molecule away from
the ionised molecule cluster. We wanted to know the energy required for
this fragmentation process, since, conversely, this also tells us the
energy with which this part is bound to the rest of the molecule,"
explains Märk. Märk and his team succeeded in breaking a C2
carbon molecule away from the C60 ion and therefore established
the measure of stability, i.e. the precise binding energy. The astonishing
result: the binding energy required to break away a C2 molecule,
at 10 electron volts, is considerably higher than the ionisation energy
of approximately 7.6 eV - this makes C60 very different from
other molecules.
Prof. Dr. Tilmann Märk
University of Innsbruck, Institute of Ion Physics
Tel.: ++43 512 507-6240
Released by:
CLOOS + PARTNER, Public Relations Agency
Tel: ++43 1 710 85 99
October 15th, 2001
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