Probing nuclear processes 'in the line of fire'

The study of nuclear processes of lower cross-sections (in comparison with, say, elastic scattering), such as, sub-barrier fusion reactions, formation of heavy compound nuclei at high angular momenta which survive fission, transfer reactions around Coulomb barrier, long-lived isomer decay in nuclei, etc. are further complicated by the intense primary beam and other strong background events. The wealth of information that could be extracted from such processes can be tapped with the use of large, highly selective (or discriminative) and efficient class of devices called recoil separators or recoil mass spectrometers (RMS) if the mass of the reaction products are also measured by the same device.

Heavy Ion reaction Analyzer (HIRA), which is Asia's first operational RMS and indigenously designed and commissioned in 1991 at Nuclear Science Centre (erstwhile name of IUAC), has been (and is still being) used in multitude of studies and in the production of low intensity, pure 7Be radioactive ion beam (RIB), the first RIB to be used in experiments in India. Another unique facility named HYbrid Recoil mass Analyzer (HYRA) which is a dual-mode, dual-stage recoil separator/mass spectrometer, funded by DST, has been designed and commissioned at IUAC to exploit the high energy beams from superconducting LINAC and planned high intensity beams from High Current Injector (HCI) at IUAC. The power of HYRA has been enhanced by the coupling of TIFR 4-pi spin spectrometer in order to realize a unique facility which measures angular momentum distributions in very heavy nuclei as well as spin-gated Giant Dipole Resonance (GDR) decay from hot, rotating nuclei.

In this talk, after briefly introducing the nuclear physics facilities at IUAC, the salient features of these devices will be highlighted through results obtained from various experimental programme carried out with them.

About Dr. N.Madhavan:

Dr. N.Madhavan did his M.Sc. Physics from IIT Bombay; M.Sc. Physics (Specialization: Accelerator Physics) from University of Manitoba, Winnipeg, Canada and Ph. D. (Nuclear Physics) from Jawaharlal Nehru University, New Delhi. He is currently Scientist (H) and Programme Leader, Nuclear Physics Group at IUAC. His areas of interest include Nuclear Reactions (Fusion around Coulomb barrier), Spin distributions, Recoil Mass Spectrometers and Beam-Optics.