Direct particle temperature measurements in dusty plasmas
Abstract
Particle temperature, the random thermal motion of particles immersed in a plasma, has a strong influence on the structure and binding of plasma crystal assemblies. For example, the formation of stable, well ordered dust arrangements is not possible under conditions where the thermal energy is larger than the binding or confining potential energy. To characterize the thermal temperature, we have employed two different techniques. The first was based upon traditional image analysis of the particle motion using digitized images from cameras and post processing. The second used a laser interferometer system to measure the motion of individual particles. The laser interferometer has significant advantages over the traditional image analysis techniques including higher velocity resolution and good spatial discrimination. We will compare temperature measurements obtained using the two systems and discuss the experimental challenges associated with using a laser interferometer with a 6 um target. The particle temperature as a function of number of particles and structure as well as the implications for particle heating mechanisms will also be discussed. This work was supported by the Division of Material Sciences, BES, Office of Science, U. S. Department of Energy and Sandia National Laboratories, a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- September 2004
- Bibcode:
- 2004APS..GECBS1005H