Formation of bubbles, blobs, and surface cusps in complex plasmas

Area of Science:

• Plasma Physics
• Soft Matter Physics

Background:

• Complex plasmas with vertical temperature gradients exhibit unique behaviors.
• Understanding microparticle dynamics is crucial for various scientific applications.

Purpose of the Study:

• Investigate the dynamical evolution of complex plasma under specific conditions.
• Characterize the formation and control of microparticle structures.
• Explore nanoscale surface tension effects and driving mechanisms.

Main Methods:

• Experimental investigation of complex plasma.
• Control of parameters like radio frequency (rf) power and gas pressure.
• Observation of microparticle structures (bubbles, blobs, cusps).
• Tracing individual microparticle motion to study atomistic dynamics.

Main Results:

• Observed formation of microparticle bubbles, blobs, and spraying cusps at low power.
• Demonstrated control over these structures by adjusting rf power and gas pressure.
• Identified evidence of surface tension at the nanoscale (hundreds of particles).
• Studied pressure dependence of forces acting on microparticles.

Conclusions:

• The observed phenomena in complex plasma are controllable via external parameters.
• Surface tension plays a role even at the nanoscale.
• Rayleigh-Taylor instability is a potential mechanism driving these complex plasma dynamics.