We, at the Accelerator Based Atomic Physics lab, mostly focus on the study of Interaction of highly charged ions and fast electrons with simple atomic and molecular systems like H, He, H2, complex molecular systems like C60 and large bio-molecules. We address questions related to the quantum mechanical interference in ionization of molecules like H2 , N2 and O2 etc. Also we study the collective behaviour of electrons in large molecules like C60. Recently, we have also been interested in the study of fragmentation dynamics of small di- and tri-atomic molecular systems in collisions with highly charged ions from ECRIA.
We carryout our experiments with slow and highly charged ion beams from an ECR based ion accelerator facility (ECRIA) as well as fast highly charged ion beams from the BARC-TIFR 14 MV tandem Pelletron-Linac accelerator facility at TIFR. We use different measurement techniques such as electron spectroscopy, time-of-flight mass spectrometry and high resolution x-ray spectrometry. Recently we have developed a Recoil Ion Momentum Spectrometer (RIMS) to study the fragmentation dynamics of small molecular systems.
Some Recent Results:
•Radiative decay of auto ionizing doubly excited states in He like highly charged ions. First observation of the fluorescence-active doubly excited states in He-like Si, S, and Cl ions measured using a bent crystal x-ray spectrometer.
•Total ionization cross section of Uracil in collisions with highly charged ions from ECRIA and Pelletron. A comparative study of total ionization cross sections measured over a wide range of energies which covers the Bragg peak region in hadron therapy.