Dusty Plasmas

In a plasma small particles get electrical charge, so they can float in the electrical fields in a plasma.  The picture shows individual 10 micrometer particles floating freely. Using a laser they can be seen even by the naked eye.

 

 

 

 

 

 

 

Gabriela Paeva

is studying basic phenomena in dusty plasmas including single particle dynamics, void formation in Coulomb  Crystals and particle coating. 

The picture shows how micrometer size particles suspended in the plasma arrange themselves in a crystal like structure. Very much like single atoms in a solid state crystal.

Dusty plasma technology can have an important industrial impact.  Misha Sorokin and Jerome Remy are studying nanoparticle formation in silane plasmas. These plasmas are used for novel solar cell fabrication. Nanoparticles inside the solar cell have a very benificial effect in lifetime and efficiency of the cell. Our aim is to understand particle formation and the role of nano-particles in amorphous silicon solar cell deposition. 

 

Misha Sorokin (project page) is studying electrical characteristics of a dusty silane plasma in the initial phases of particle formation. A commercial probe is used to measure voltage and current and their phase difference. The electron density is measured using a microwave resonance technique, while the particle charge is measured by laser induced photodetachment. (This technique is explained in the thesis of Eva and Winfred Stoffels.) 

For this work an afstudeer project is available .

 

Jerome Remy  uses also studies the initial phases of particle growth in a silane plasma. However, he focuses on the chemical aspects of particle growth and its impact on the plasma composition. He uses infrared cavity ringdown spectroscopy to detemine the density of various species. The CRDS technique has been developed by Marcel Hemerik. (thesis 3MB pdf file / abstract).

Also on this project an afstudeer project is available.

The dusty plasma research is supported by  Winfred Stoffels so  you can always contact him with questions and suggestions.

 

 

 

Dusty plasmas have been studied in the group EPG since 1991. There are many fundamental and technological aspects related to the study of dusty plasmas.  There is more background information.and an extended review. 

Apart from normal plasma diagnostics a variety of diagnostics have been developed to study various particle related properties

• Charge measurement by laser induced photo detachment (paper1 , paper2)
• Particle size and density by Mie scattering (paper , Angle resolved Mie scattering during etching of an MF particle (compressed animated gif)), laser induced heating (paper1 , paper2) and ellipsometry (Thesis Swinkels)
• Particle temperature by temperature dependent fluorescence (model , thesis Swinkels)
• Composition by infrared absorption spectroscopy (paper1 , paper2) and SEM (paper)
• Particle dynamics by Laser Light scattering and video imaging (carbon particle formation), and laser Doppler methods

               

Apart from various items mentioned above laser induced powder formation in methane (Power point presentaion 3.7 MB)  and plasma formation of MoS2 powder (power point presentation 4.5 MB) have also been studied. The PhD theses of Winfred and Eva Stoffels (10 MB pdf file) as well as the thesis of Geert Swinkels (3.7 MB pdf file) are devoted to dusty plasmas. 

 

 Geert Swinkels wrote an impression on dusty plasma research, unfortunately it is in dutch.