Study of the formation of nanoparticles in dusty plasmas (2000 - )

Formation of nano-metre sized particles in Silane plasmas used in plasma deposition processes have been experimentally seen to influence the properties of the formed wafer. This work aims at understanding the mechanism behind the formation of such small particles. To this end, molecular dynamic studies are being conducted on the clustering processes that occur at the very initial stages of dust formation. A detailed study of the formation, charging and motion of such particles hold the key to understanding how they influence the film deposition. The work is being done at the Department of Applied Physics, Eindhoven University of Technology in the Netherlands.

Theoretical and numerical study of capacitive radio frequency discharges (1999-2000)

Low pressure rf capacitive plasma discharges have an application in reactive ion etching. In this work, a theoretical model of capacitive rf discharge was formulated, taking into account various collissional processes, in order to compute the power absorbed by such discharges, especially in electronegative gases like oxygen. The theoretical model has been validated against available experimental data. The work was conducted at the Electrical Engineering Department of the University of Windsor in Canada.

Detection and localization of partial discharges in electrical GIS structures using acoustic emission techniques.(1994-1998)

Detection of partial discharges due to defects within Gas Insulated Substations forms an important part of GIS diagnostics. Presence of inherent defects like fixed protrusions on the surfaces of the electrodes, or presence of floating particles in the gaseous insulating medium within the GIS, can cause partial discharges to occur. Partial discharges basically involve a short burst of current of nanosecond duration, and traditionally electrical techniques have been employed in their detection. However, in recent times, acoustic techniques used in conjunction with electrical methods have been seen to be effective. Partial discharges occurring within the GIS set up pressure waves in the insulating gas which propagate through the gas and set up vibrations in the body of the metal enclosure. This work involved a detailed numerical modeling of the physical process of emanation, propagation and detection of acoustic signals from partial discharges occurring within Gas Insulated Substations. Algorithms for detection as well as localization of these signals (including methods of processing them) were proposed and detailed experiments were carried out on a prototype GIS. The work was done at the High Voltage Engineering Department of the Indian Institute of Science.

Fractal based numerical modeling of treeing in XLPE cables.(1992-1994)

This work comprised of numerical modelling of treeing produced by electrical activity in XLPE cable insulation, and analysis thereof using fractal dimension of the trees as a characterizing parameter. Experiments were performed for validation of the model, and fractal dimensions of experimentally and numerically grown trees were compared to determine the validity of fractal measures as a characterizing parameter for electrical trees. The work was done at the High Voltage Engineering Department of the Indian Institute of Science.