TITLE: "Wave Connections in Space and Fusion Laboratory Plasmas"

SPEAKER: Professor Cynthia K. Phillips,

TIME: Thursday Jan. 17, 2002 at 4 PM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

This lecture is sponsored in part by the Division of Plasma Physics of the American Physical Society and the Distinguished Lecturers in Plasma Physics Program.

Over 99% of the observable universe exists as a plasma in which collective long range electromagnetic interactions among a multitude of charged particles dominate over short range inter-particle interactions. A wide variety of phenomena ranging from radio-wave communications, magnetospheric disturbances, distance determination to astrophysical objects such as pulsars, and control of magnetically confined laboratory plasmas for fusion energy research are all dependent on the existence of waves in plasmas. In plasmas, the nuclear fusion reactions that fuel the sun can occur naturally. This presentation will begin with an introduction to the key physics challenges that must be met in order to realize the potential of controlled thermonuclear fusion as a clean, abundant energy souce here on earth. Attention will then be focused on the dynamics and utilization of electromagnetic waves for auxiliary control of magnetically confined plasmas. The specific process of mode conversions, in which the propagation of one particular wave can lead to excitation of another due to localized inhomogeneities in the plasma, will be introduced. This process is fundamental to understanding one of the most successful methods developed for the heating of fusion-relevant plasmas, as well as to providing the mechanism for propagation of waves between the earth's magnetosphere and ionosphere.