UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 17:57
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Conference: Bucharest University Faculty of Physics 2022 Meeting


Section: Solid State Physics and Materials Science, Optics, Spectroscopy, Plasma and Lasers


Title:
Electron beam induced dust flows in a plasma crystal


Authors:
Dorina TICOS (1), Adrian SCURTU (1), Jeremiah WILLIAMS (2), Maria Luiza MITU (1), Cătălin M. TICOS (1)


Affiliation:
1) National Institute for Laser, Plasma and Radiation Physics, Măgurele, Ilfov 077125, Romania

2) Wittenberg University, Physics Department, Springfield, Ohio 45504, USA



E-mail
dorina.toader@inflpr.ro


Keywords:
dusty plasma, electron beam


Abstract:
Dusty plasmas are ubiquitous in nature being encountered in space and astrophysical objects but also in laboratory plasmas such as in the semiconductor fabrication processes that employs cold plasmas for manufacturing chips [1-2]. Besides the typical plasma constituents (electrons, ions, electric and magnetic fields, and radiation), dusty plasmas have in their composition one unique component: particulates of solid matter (or dust) made up of a large number of atoms. It is the presence of these dust particles that lead inherently to some unusual physical properties, from single or collective behavior to self-organization and the existence of a multi-range of time and space scales. In laboratory plasmas, the dust particles are electrically charged and settle in the sheath surrounding one of the electrodes and are suspended by the electric force of the sheath field. Particles with different masses settle at different positions inside the sheath, depending on their charge and electric field spatial profile [3]. We review some experiments performed in our lab in which an external electron beam with energy ~10 keV and with a current of a few milliamps can induce some interesting nonlinear dynamical phenomena within a plasma crystal, from laminar to turbulent dust flows and formation of vortices [4,5]. The visualization of electron beam-driven dust flows is realized using the particle image velocimetry (PIV) technique for mapping the velocity fields [4,5] or the particle tracking velocimetry (PTV) technique for inferring the dynamical features at the particle level [6].


References:

[1] A Mamun, PK Shukla, Introduction to Dusty Plasma Physics, IoP, Bristol, 2001

[2] A. Barkan, R.L. Merlino, N. D'Angelo, Laboratory observation of the dust-acoustic wave mode. Phys. Plasmas 2, 3563 (1995).

[3] C. M. Ticos, A. Dyson and P. W. Smith, The charge on falling dust particles in a RF plasma with DC negative bias, Plasma Sources Sci. Technol. 13, 395 (2004).

[4] C. M. Ticoş, D. Ticoş, J.D. Williams, Kinetic effects in a plasma crystal induced by an external electron beam, Physics of Plasmas 26, 43702 (2019).

[5] C.M. Ticoş, D. Ticoş, J.D. Williams, Pushing microscopic matter in plasma with an electron beam, Plasma Physics and Controlled Fusion 62, 25003 (2020).

[6] D. Ticoș, A Scurtu, J.D. Williams, L. Scott, E. Thomas Jr., D. Sanford, C.M. Ticoș, Rotation of a strongly coupled dust cluster in plasma by the torque of an electron beam, Physical Review E 103, 023210 (2021).

Acknowledgement:
Work financed by The Ministry of Education through LaPlas VI Programme PN 1915, contract nb. 16N/2019