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Highly charge ions are atoms with very high degree of ionization, due to their unshielded coulomb field the interaction which are negligible in in neutral mode become dominant because they scale with different powers of nuclear charge Z. Electron binding energy is large so Coulomb field has a long range interaction which enhances intensity of multipole transitions. The reduced electron screening causes inner shell effects to become more important. All of the these properties are dependent on Z which can be treated as a controllable experimental parameter. Accurate atomic reference data based on the physical parameters such as energy level and lifetime are essential requirement for development of astrophysical models that may be used to simulate the astrophysical observation of interest so as to extract macroscopic information about non-terrestrial objects. Further such experimental data bank can be used to test the accuracy as well as the reliability of "classical atomic theories " which are used for calculation of various physical parameters of neutral as well as semi neutral atoms. However the atomic data on highly charged ions are very scanty. Data are available from beam-foil spectroscopy. However accuracy of such data comes in to question due to population of various charge states in beam-foil interactions which results in satellite blending of the transitions of interest. Only solution to the problem is to use detectors having resolution about 20 times better that that of commercially available X-ray energy dispersive detectors.
In recent couple of years, lot of efforts have been put in collaboration with various National Universities and Institutes to build the various facilities. Especially, facility for lifetime measurement of metastable states using beam- single and beam- two -foil techniques have been developed indigenously using solid state X-ray energy dispersive detectors. Lifetime measurement setup have flight path of about 80 mm which makes it possible to make experimental study of states with lifetime up to a few hundred pico seconds. Experiments using beam- single- foil as well as
beam-two- foil technique in determining the lifetimes of both parent as well as satellite lines. Thus the setup is only of its kind in at International Level. The analysis of time of flight data is not at all straight forward due to the population of the various charge states in the post foil beam. A novel data analysis technique applying iterative multi-component exponential growth and decay analyses to separate contribution from transitions in other charge states that cannot be spectrally resolved has been developed .
The present model analysis is base on certain approximations on beam -foil excitation mechanism. To get rid of such approximation in the analysis, presently the research efforts are focussed on development of an ultra high resolution Doppler Tuned Spectrometer which would have resolution of about 5-10 eV at ~6 keV. Development of this facility would access to inner cores of the atomic structure never explored before.
It may be worth noting that besides the reliable lifetimes this method gives us opportunity to investigate the mechanism of excited states interacting with a thin carbon foil. Some experiments have been performed to study the intra-shell transition mechanism.
Further, X-ray lines out of the expected window in the beam-foil spectra have been analyzed to be originated from electron capture processes followed by nuclear events. Investigations on these lines have opened up a new opportunity to study rare phenomenon such as ternary recombination.