Engineering topics

Coueedel, Lenaiec

Publications and source records attributed to Coueedel, Lenaiec.

2 records

DOE OSTI2011

Comprehensive experimental study of heartbeat oscillations observed under microgravity conditions in the PK-3 Plus laboratory on board the International Space Station

Heartbeat oscillations in complex plasmas with a broad range of fundamental frequencies are observed and studied. The experiments are performed with monodisperse microparticles of different diameters in argon as well as in neon plasmas. The oscillation frequency increases with increasing rf power and neutral gas pressure. At the lower frequencies, oscillations are strongly nonlinear. The microparticle pulsations, the variation of the electrical discharge parameters and the spatially resolved changes in the plasma glow are proven to be strongly correlated. Heartbeat oscillation dynamics is associated with global confinement modes.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2010

Threshold Phenomena in a Throbbing Complex Plasma

In complex plasmas, the trapped dust particle cloud is often characterized by a central dust-free region ('void'). The void induces a spatial inhomogeneity of the dust particle distribution and is at the origin of many intricate unstable phenomena. One type of this kind of behavior is the so-called heartbeat instability consisting of successive contractions and expansions of the void. This instability is characterized by a strong nonlinear dynamics which can reveal the occurrence of incomplete sequences corresponding to failed contractions. Experimental results based on high-speed imaging are presented for the first time and underline this threshold effect in both the dust cloud motion and the evolution of the plasma light emission.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗