2012 Spring Physics Colloquium Series: Dr. Ke Qiao

DateJanuary 25, 2012
Time4:00 - 5:00 pm
LocationBaylor Sciences Building, Room E.125
Description
Ke Qiao, Ph.D.

Assistant Research Scientist, CASPER

Baylor University


Wave Modes, Instabilities and Phase Transitions in Plasma Crystals and Dust Clusters in Dusty Plasmas


Dusty (complex) plasmas are composed of micron sized particles immersed in a weakly ionized gas. It has been around for several decades with topics in astrophysics, planet formation, solar system research, planetary rings, atmospheric lightening, and plasma technology, and received a major boost in 1994 when liquid and crystalline plasmas were discovered.


Research in dusty (complex) plasmas mainly falls in two classes, (1) on the effects of dusts on plasmas, and (2) on the structure and dynamics of the dust system. The former is a subfield of plasma physics and focused on topics such as plasma properties around the dusts, electron and ion waves affected by the dusts; the latter is actually more closely related to physics in condensed and soft matter systems, modeled by the dust system. Topics include structures, waves and phase transitions of the system. In this talk, our previous and more recent researches using numerical simulations on dust lattice waves (DLWs) in two dimensional (2D) plasma crystals and normal modes in 2D dust clusters will be reported. Related instabilities and phase transitions will be discussed. A special kind of instability unique to dusty plasmas, induced by the ion wakefield around dusts, which in turn caused by the openness of the system, will be proposed to be cause of the experimentally observed melting. A brief report of a recent research on the plasma sheath, using the dust particles as a probe, will also be given.


For More information contact: Dr. Anzhong Wang x 2276

PublisherDepartment of Physics
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