Mini-conference on helicon plasma sources

The first two sessions of this mini-conference focused attention on two areas of helicon source research: The conditions for optimal helicon source performance and the origins of energetic electrons and ions in helicon sourceplasmas. The final mini-conference session reviewed novel applications of helicon sources, such as mixed plasma source systems and toroidal helicon sources. The session format was designed to stimulate debate and discussion, with considerable time available for extended discussion.E.E.S. and A.M.K. acknowledge support for this work from NSF award No. PHY- 0611571

Storm time equatorial magnetospheric ion temperature derived from TWINS ENA flux

The plasma sheet plays an integral role in the transport of energy from the magnetotail to the ring current. We present a comprehensive study of the equatorial magnetospheric ion temperatures derived from Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) energetic neutral atom (ENA) measurements during moderate to intense (Dstpeak < −60 nT) storm times between 2009 and 2015. The results are validated using ion temperature data derived from the Geotail low‐energy particle energy analyzer and the Los Alamos National Laboratory magnetospheric plasma analyzer. The ion temperatures are analyzed as a function of storm time, local time, and L shell. We perform a normalized superposed epoch analysis of 48 geomagnetic storms and examine the spatial and temporal evolution of the plasma as a function of storm phase. This analysis illustrates the spatial and temporal variation of the ions from the plasma sheet into the inner magnetosphere. We find that the ion temperature increases approaching the storm peak. This enhancement has the largest magnetic local time extent near 12 RE distance downtail.Key PointsWe derive and statistically examine storm time equatorial magnetospheric ion temperatures from TWINS ENA fluxThe TWINS ion temperature data are validated using Geotail and LANL ion temperature dataFor moderate to intense storms the widest (in MLT) peak in nightside ion temperature is found to exist near 12 REPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137478/1/jgra53387.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137478/2/jgra53387_am.pd

Electron and proton heating by solar wind turbulence

Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons, and is exchanged between them via collisions. Comparison to available Ulysses data shows that a reasonable accounting for the data is provided when (i) the energy exchange timescale is very long and (ii) the deposition of heat due to turbulence is divided, with 60% going to proton heating and 40% into electron heating. Heat conduction, determined here by an empirical fit, plays a major role in describing the electron data