Experimental evidence of early-time linear-saturation of the ion-Weibel instability in counterstreaming plasmas
ORAL
Abstract
The ion-Weibel instability is a leading candidate mechanism for the formation of collisionless shocks observed in many astrophysical systems. Experimental and computational studies have shown that the ion-Weibel instability drives current filamentation in counterstreaming plasma flows with the capability to mediate collisionless shock formation and subsequent particle acceleration in the lab. The present work focuses on the study of nonlinear ion-Weibel evolution under various plasma conditions through utilization of different ion species and experimental geometries. Path-integrated B-field distributions are retrieved from experimental proton images and Fourier analyzed to compare with linear theory based on benchmarked radiation-hydrodynamic simulations. The new analyses presented here indicate that the first ~400ps of the collisionless interaction between the two flows dominates the spectral evolution of Weibel filaments, with typical wavelengths of ~300μm and B-field amplitudes of ~1-3T.
*This work was supported by the DOE, NNSA under award number DE-NA0003842. Work by LLNL was performed under the auspices of the U.S. DOE under Award No. DE-AC52-07Na27344. Prior support for M. J.-E. Manuel for this work was provided by NASA through Grant No. PF3-14011.
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Publication: Manuel, M. J.-E. et al. (in prep), "Experimental evidence of early-time linear-saturation of the ion-Weibel instability in counterstreaming plasmas"
Presenters
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Mario J Manuel
- General Atomics - San Diego