Laboratory Observations of Ultra-low-frequency Analog Waves Driven by the Right-hand Resonant Ion Beam Instability

Abstract

The right-hand resonant instability (RHI) is one of several electromagnetic ion/ion beam instabilities responsible for the formation of parallel magnetized collisionless shocks and the generation of ultra-low frequency (ULF) waves in their foreshocks. This instability has been observed for the first time under foreshock-relevant conditions in the laboratory through the repeatable interaction of a pre-formed magnetized background plasma and a super-Alfvénic laser-produced plasma. This platform has enabled unprecedented volumetric measurements of waves generated by the RHI, revealing filamentary current structures in the transverse plane. These measurements are made in the plasma rest frame with both high spatial and temporal resolution, providing a perspective that is complementary to spacecraft observations. Direct comparison of data from both the experiment and the Wind spacecraft to 2D hybrid simulations demonstrates that the waves produced are analogous to the ULF waves observed upstream of the terrestrial bow shock.

Magnetic reconnection and kinetic waves generated in the Earth's quasi-parallel bow shock

“…[20][21][22][23][24][25][26][27][28] Space measurements (Ref. 29 and references therein) as well as laboratory experiments 30 have been observing these predicted waves. Also, in a steepened wave structure such as SLAMS (short, large-amplitude magnetic structures), 31 high-frequency waves such as whistler waves can be generated 27,32 (for space observations, see Ref.…”

Astrophysical Explosions Revisited: Collisionless Coupling of Debris to Magnetized Plasma

“…Test cases using an adiabatic electron equation of state ( with ) showed little difference in the bulk dynamics of our simulations, which is primarily controlled by the electromagnetic coupling between the debris and background ions. Similar hybrid models have been used previously to study general astrophysical explosions (Bashurin et al., 1983; Brecht et al., 2009; Hewett et al., 2011; Winske & Gary, 2007) and shocks (Lembège & Simonet, 2001; Thomas & Brecht, 1986), as well as problems related to chemical releases in the magnetosphere (Bernhardt et al., 1987; Delamere et al., 1999) and laser‐driven laboratory experiments (Clark et al., 2013; Heuer et al., 2020; Weidl et al., 2016).…”

“…Debris ions moving mainly parallel to the background magnetic field couple weakly to the ambient plasma. Rather than coupling through the Larmor mechanism (Bashurin et al., 1983; Golubev et al., 1978), the parallel‐streaming ions couple to the background primarily through ion‐ion beam instabilities (Gary et al., 1984; Heuer et al., 2020; Weidl et al., 2019). This coupling is comparatively weak, and in all our cases, a population of ions streams nearly freely from the explosion for at least several hundred ion inertial lengths.…”

Astrophysical explosions revisited: collisionless coupling of debris to magnetized plasma

“…Test cases using an adiabatic electron equation of state (p e ∝ n γ with γ = 5/3) showed little difference in the bulk dynamics of our simulations, which is primarily controlled by the electromagnetic coupling between the debris and background ions. Similar hybrid models have been used previously to study general astrophysical explosions (Bashurin et al, 1983;Winske & Gary, 2007;Brecht et al, 2009;Hewett et al, 2011) and shocks (Thomas & Brecht, 1986;Lembège & Simonet, 2001), as well as problems related to chemical releases in the magnetosphere (Bernhardt et al, 1987;Delamere et al, 1999) and laser-driven laboratory experiments (Clark et al, 2013;Weidl et al, 2016;Heuer et al, 2020).…”