Séminaire ISTerre

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Acoustic plasma trapping and plasma thermoacoustics

lundi 22 février 2021 - 17h00

Seth Pree - Caltech
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An oven’s worth of microwave power can turn 30 mg of sulfur contained in a ping-pong ball sized bulb into a 3000 K plasma. Modulating that microwave power generates sound within the bulb. Tuning the modulation frequency to an acoustic resonance of the cavity, ~30 kHz, generates a spherically symmetric acoustic standing wave with a Mach number around .03. In this seminar I will show how such an intense sound field acoustically traps the plasma in the center of the bulb. This capability can be understood via a generalization of the acoustic radiation force that acts on density gradients in the fluid through which sound propagates. I will present ideas how using acoustics to manipulate this plasma may enable a laboratory model of thermal convection in a central force, a diagnostic for collisional plasmas, and a type of self- oscillator based on time-varying plasma properties.

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Equipe organisatrice : Géodynamo

Séminaire uniquement en visio

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/97116158870?pwd=MmEvVXovSG1jbzBUV1JGVjcySit0Zz09