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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2026-06-11 23:58 |
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Conference: Bucharest University Faculty of Physics 2026 Meeting
Section: Atomic and Molecular Physics. Astrophysics. Applications. Optics, Spectroscopy, Plasma and Lasers
Title:
High-energy pulsed electron beam-induced phase transitions in a plasma cluster with a crystalline structure
Authors:
Beatrice PARASCHIV (1,2), Dorina TICOȘ (1), Nicoleta UDREA (1), Maria L. MITU (1), Adrian SCURTU (1), Cătălin M. TICOȘ (1,3)
*
Affiliation:
1) National Institute for Laser, Plasma and Radiation Physics (INFLPR), Măgurele 077125, Romania
2) Engineering and Applications of Lasers and Accelerators Doctoral School (SDIALA), National University of Science and Technology Politehnica of Bucharest, 313 Splaiul Independenței St., Bucharest RO-060042, Romania
3) Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Măgurele 077125,
E-mail
beatrice.paraschiv@inflpr.ro
Keywords:
electron beam, particle tracking velocimetry (PTV), phase transitions, dusty plasma
Abstract:
Clusters with crystalline structure formed by charged microparticles in complex plasmas exhibit ordered states that can undergo phase transitions under external driving [1,2]. While temperature and pressure effects are well studied, the influence of electron beam excitation remains less explored [3]. This work investigates the melting dynamics of a micrometer-sized plastic sphere cluster suspended in an RF argon plasma, driven by a pulsed electron beam with energies between 9 and 14 keV.High-speed imaging (60 fps) enables particle tracking and structural analysis using Voronoi diagrams, pair correlation functions g(r), and particle tracking velocimetry (PTV). At 9–10 keV, the system shows gradual disordering with hexatic-like behavior and continuous structural changes, indicating a smooth transition. At 11–14 keV, rapid destabilization occurs, with chaotic motion, abrupt collapse of g(r), and melting times decreasing from ~0.6 s to ~0.1 s. The transition involves collective rotation at lower energies followed by shear-induced instabilities leading to complete melting at higher energies.Velocity and kinetic energy distributions confirm distinct transition regimes. Overall, the results demonstrate that electron beam energy can effectively control phase transitions in plasma crystals, providing insight into non-equilibrium dynamics and potential applications in plasma physics, materials science, and related fields.
References:
[1] Morfill, G. E., & Ivlev, A. V. (2009). Complex plasmas: An interdisciplinary research field. Reviews of Modern Physics,
81(4), 1353–1404.
[2] Fortov, V. E., et al. (2005). Complex (dusty) plasmas: Current status, open issues, perspectives. Physics Reports, 421(1–2),
1–103.
[3] Thomas, H. M., & Morfill, G. E. (1996). Melting dynamics of a plasma crystal. Nature, 379, 806–809.
Acknowledgement:
This research was funded by Romanian Ministry of Research, Innovation and Digitalization on project PN LAPLACE VII, Contract No. PN 23 2101 05.
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