Our team studies
the properties of highly charged ions (HCI)
produced with an electron beam ion trap (EBIT). Due
to the technical challenges implied, only very few laboratories in the
world can produce and store such ions, which can
have a charge state as high as Hg78+ , a mercury ion with only two electrons
left, or even "naked" U92+ which can currently be trapped in a single device (SuperEBIT at LLNL). The
Heidelberg EBIT is one of the three high-energy EBITs in operation, and
started working in the year 2001.
 Highly charged ions
are very common in the universe, since the heaviest bodies are usually at
very high temperatures, and atoms loose most of their electrons in those
environments. Such ions offer important advantages for basic research in quantum
electrodynamics at extreme fields, relativistic atomic structure theory and
nuclear size contributions. Fundamental effects
grow in size with high powers of the ionic charge state, or Z, thus
becoming increasingly dominant and easier to measure. At the same time, less electrons mean that the electronic structure
becomes easier to handle for theory. simpler. But
accurate knowledge of the properties of
HCIs is also necessary for the diagnostics of hot
astrophysical plasmas and fusion energy research, since theoretical methods
currently do not reach the precision currently achieved in experiments.
Different
spectroscopic techniques from the x-ray to the visible range, as well as laser spectroscopy, are applied at the Heidelberg EBIT
to the study of HCIs. Ions extracted from
the trap are also used
to investigate collisions processes of highly charged ions with electrons,
atoms and molecules. Major projects have also been started to investigate the properties
of short-lived radioactive isotopes and to apply the recently developed
x-ray free electron laser to ions stored in an EBIT.
Contact: José Crespo López-Urrutia
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