Observation of Le Sage gravity analog in complex plasma

Area of Science:

• Plasma physics
• Microparticle dynamics
• Astrophysical phenomena

Background:

• Microparticle suspensions in plasma are susceptible to complex interactions.
• Understanding microparticle behavior is crucial for plasma-based applications and astrophysical modeling.
• Previous theories suggested attractive forces in dense plasmas, but experimental evidence was limited.

Purpose of the Study:

• To experimentally investigate the fragmentation and globule formation of microplastic particles in gas discharge plasma.
• To explore the underlying mechanisms, particularly plasma-induced attraction.
• To draw parallels between observed phenomena and astrophysical processes.

Main Methods:

• Experimentally inducing fragmentation and globule formation by abruptly increasing plasma density.
• Observing and measuring the size and structure of formed globules.
• Demonstrating the role of plasma flows by reducing plasma density and observing globule disintegration.
• Utilizing molecular dynamics simulations to model microparticle cloud fragmentation and globule formation.

Main Results:

• Successfully fragmented microplastic particles and formed dense, spherical globules (0.14-1.1 mm diameter) containing tens to thousands of microparticles.
• Attributed globule formation to a Le Sage's-like attraction mechanism driven by plasma losses within globules.
• Visually confirmed the critical role of plasma flows in particle attraction through globule disintegration upon plasma density reduction.
• Molecular dynamics simulations qualitatively reproduced fragmentation and globule formation patterns seen in interstellar nebulae.

Conclusions:

• Gas discharge plasma can induce fragmentation and self-assembly of microplastic particles into dense globules.
• The observed phenomenon is driven by plasma-induced attractive forces, analogous to gravitational instability and Le Sage's theory.
• The experimental findings and simulations offer a novel experimental model for studying astrophysical fragmentation and collapse processes.