| 1. |
- Greiner, Franko, et al.
(author)
-
Diagnostics and characterization of nanodust and nanodusty plasmas
- 2018
-
In: European Physical Journal D. - : SPRINGER. - 1434-6060 .- 1434-6079. ; 72:5
-
Journal article (peer-reviewed)abstract
- Plasmas growing or containing nanometric dust particles are widely used and proposed in plasma technological applications for production of nano-crystals and surface deposition. Here, we give a compact review of in situ methods for the diagnostics of nanodust and nanodusty plasmas, which have been developed in the framework of the SFB-TR24 to fully characterize these systems. The methods include kinetic Mie ellipsometry, angular-resolved Mie scattering, and 2D imaging Mie ellipsometry to get information about particle growth processes, particle sizes and particle size distributions. There, also the role of multiple scattering events is analyzed using radiative transfer simulations. Computed tomography and Abel inversion techniques to get the 3D dust density profiles of the particle cloud will be presented. Diagnostics of the dust dynamics yields fundamental dust and plasma properties like particle charges and electron and ion densities. Since nanodusty plasmas usually form dense dust clouds electron depletion (Haynes effect) is found to be significant.
|
|
| 2. |
- Greiner, Franko, et al.
(author)
-
Imaging Mie ellipsometry: dynamics of nanodust clouds in an argon-acetylene plasma
- 2012
-
In: Plasma sources science & technology. - : Institute of Physics. - 0963-0252 .- 1361-6595. ; 21:6, s. 065005-
-
Journal article (peer-reviewed)abstract
- For the in situ analysis of nano-sized particles in a laboratory plasma, Mie ellipsometry is a well established technique. We present a simple setup with two CCD cameras to gain online spatiotemporal resolved information of the growth dynamics of particles which are produced by plasma chemical processes in an argon-acetylene plasma. Imaging Mie ellipsometry proves to be a powerful technique to study the growth processes of nanodust in all its details.
|
|
| 3. |
- Pilch, Iris, et al.
(author)
-
Diagnostics of void expansion during cyclic growth and formation of layered nanoparticle clouds
- 2017
-
In: Journal of Applied Physics. - : AMER INST PHYSICS. - 0021-8979 .- 1089-7550. ; 121:11
-
Journal article (peer-reviewed)abstract
- Nanoparticles were grown in an argon-acetylene plasma, and the particle size was characterized during growth using imaging Mie ellipsometry (I-Mie). The typical cyclic growth was observed, and the previously reported expansion and contraction of the void before depletion of nanoparticles [van de Wetering et al., J. Phys. D: Appl. Phys. 48, 035204 (2015)] was independently confirmed in our measurements. The cyclic growth was interrupted by repetitively turning the acetylene flow on and off. The nanoparticles that were confined in the discharge proceeded to grow slowly but more importantly a new growth cycle started with nucleation and growth taking place in the void region. The additional growth burst in the void region leads to a structured dust cloud with regions of nanoparticles with different sizes that were sharply separated. The advantages of using the I-Mie diagnostics for the observation of nanoparticles compared to standard video microscopy are demonstrated for the structured dust cloud. The results are discussed in relation to the growth processes for nucleation and coagulation.
|
|
