The analysis of new, high quality, spectroscopic observations from
space-based observatories is frequently hampered by the relative
inaccuracy of much existing atomic data (and particularly
oscillator strengths). This underlines the continuing urgency of
the calculations we undertake.
Much of our recent work has focused on the iron group elements,
in particular on Fe II, Fe III, Fe IV, Mn II and more recently on
Sc II. In this work, we collaborate with observational and experimental
researchers as part of the FERRUM project, involving experimental
groups in Stockholm and Imperial College London, and astrophysicists
at Lund and in the ARC research cluster in our own School. Experimental
determinations of oscillator strengths are obtained by combining lifetimes
measured in Lund and Stockholm with branching fractions measured in London.
This collaboration has developed further into a combined
theoretical/experimental approach to the determination of hyperfine
structure, which is another aspect of our work.
More details of our work in relation to astrophysics, as well as recent
publications, are given on the associated website Atomic Data for
Astrophysics : http://www.am.qub.ac.uk/apa/
Other recent work has focused on the need for oscillator strength data
used in the analysis of impurities in the plasmas found in tokamaks
including the planned ITER for fusion research. Our particular interest
is in neutral and singly ionised tin, for which very little accurate
atomic data exists.
Recent observations using space-based observatories have revealed the
presence of elements which previously had been undetectable. These include
the lanthanides, as well as other heavy elements. In contrast to the lighter
elements, relatively little theoretical work has so far been undertaken on
transitions in ions of these elements. In view of the importance of these
elements, we are planning to undertake a major study of such transitions,
using the GRASP program; some members of our group were involved in its