Re: Seminars in LUMS
Complex (dusty) Plasmas
Dusty plasmas are open systems of plasma (electrons, ions) and dust particles (typically micron size grains) where the sink of plasma particles, due to absorption on dust, is balanced by a plasma source. These are uniquely informative in low-temperature laboratory discharges as well in near earth environment, planetary rings and interstellar space where these are ubiquitously found. However such micron sized dust particles are an annoyance in the plasmas of fusion energy and semiconductor manufacturing. The grains can be charged negatively and positively by several mechanisms depending on the local plasma conditions and radiation sources. Furthermore, in the presence of an ensemble of charged dust grains, there are collective dust plasma interactions featuring novel phenomena e.g. waves, instabilities, coherent nonlinear structures etc.
Dusty plasma physics has appeared as one of the most rapidly growing fields of science, as demonstrated by the number of published papers in scientific journals and conference proceedings. In this talk, the basic physics of dusty plasmas as well as some collective processes will be discussed. The focus will be on the charging mechanisms, formation of dust atoms and molecules, nonlinear Landau damping of helicon waves and lower hybrid cusp soliton. It appears that collective processes in a complex dusty plasma would have excellent future perspectives in the twenty-first century, because they have not only potential applications in interplanetary space environments, or in understanding the physics of our universe, next generation ITER devices but also in advancing our scientific knowledge in multidisciplinary areas of science.
*Invited speaker: *
Zahida Ehsan
Research Officer, Salam Chair for Physics,
Government College University, Lahore
October 30,2009
Time: 16:00-17:30
Venue: SSE Auditorium 10-302