Theory and Simulation of Turbulent Heating by the Modified Two-Stream Instability

Abstract

A theory of twostream instability in two hollow relativistic electron beams

Lower Hybrid Drive in Solar Magnetic Reconnection Regions: Implications for Electron Acceleration and Solar Heating

“…The crucial point recognised and elaborated upon here is that charge-exchange in low β plasmas predominantly leads to the ion ring driving lower hybrid waves, which can then yield parallel electron acceleration through LH drive in addition to perpendicular ion heating. This has been observed near the space shuttle in Earth's ionosphere (Papadopoulos 1984;Cairns & Gurnett 1991a), is well known theoretically (McBride et al 1972;Omelchenko et al 1989;Shapiro et al 1998), and has been proposed for the 2-3 kHz radio emissions generated beyond the heliospheric termination shock (Cairns & Zank 2001). Accordingly, in Section 2 we generalise Wu and collaborators' scenario of charge-exchange in magnetic reconnection regions to include growth of lower hybrid waves and subsequent electron acceleration by LH drive, thereby placing McClements et al's (1993) work in a natural context.…”

“…This prediction is directly relevant to observations (Kohl et al 1997) of much greater oxygen ion heating than proton heating, since from (2), T ⊥O ≈ 16T ⊥H . Perpendicular ring, ring-beam, and beam distributions of ions are often unstable to the growth of lower hybrid waves (McBride et al 1972;Papadopoulos 1984;Omelchenko et al 1989;Cairns & Gurnett 1991a;McClements et al 1993;Shapiro et al 1998). These waves are primarily electrostatic and propagate primarily perpendicular to B.…”

“…The standard ones are (1) acceleration by parallel electric fields (Holman 1985;Benz 1987) and (2) stochastic acceleration via wave-particle interactions, which are reviewed in detail elsewhere (Miller et al 1997). Lower hybrid (LH) drive (McBride et al 1972) involves lower hybrid waves resonantly accelerating electrons parallel to B, as well as heating ions perpendicular to B. The mechanism has been developed extensively for multiple laboratory and space contexts, with several sources for the lower hybrid waves, including cross-field currents (Spicer, Benz, & Huba 1981;Benz & Smith 1987) and modified two-stream instabilities involving perpendicular ion beams or rings (McBride et al 1972;Papadopoulos 1984;Omelchenko et al 1989;Cairns & Gurnett 1991a;McClements et al 1993;Shapiro et al 1998;Cairns & Zank 2001).…”

“…Lower hybrid (LH) drive (McBride et al 1972) involves lower hybrid waves resonantly accelerating electrons parallel to B, as well as heating ions perpendicular to B. The mechanism has been developed extensively for multiple laboratory and space contexts, with several sources for the lower hybrid waves, including cross-field currents (Spicer, Benz, & Huba 1981;Benz & Smith 1987) and modified two-stream instabilities involving perpendicular ion beams or rings (McBride et al 1972;Papadopoulos 1984;Omelchenko et al 1989;Cairns & Gurnett 1991a;McClements et al 1993;Shapiro et al 1998;Cairns & Zank 2001). McClements et al (1993) proposed that LH drive might be relevant to first-phase acceleration of electrons and ions in solar hard X ray and gamma ray observations, with the ion ring distributions driving the lower hybrid waves.…”

Emergence of kinetic behavior in streaming ultracold neutral plasmas

“…Because of the increasing mean free path with particle kinetic energy, the situation can already change for mean free path on the order of or longer than 1% of the length scale of plasma gradients [1]. This gives rise to kinetic effects such as streaming plasmas and non-local transport, which are intensely studied because of their importance in many plasma environments, such as high-density laser-produced plasmas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and astrophysical plasmas like the solar wind [19], solar atmosphere [20,21], solar flares [22], and supernovae [23].…”