Ref: SEMIN-2019-0020

Hinode/EIS measurements of the preferential heating of minor ions in the low corona to test the role of different wave-particle mechanisms

Dolla, Laurent

Seminar presented at CmPA, KULeuven on 2019-04-04

Abstract: Preferential heating of minor, heavy ions has long been observed in the solar wind, both through in situ measurements from 0.3 to several Astronomical Unit and through remote-sensing observation closer to the Sun (up to a few solar radii). Wave-particle interactions (e.g. non-adiabatic acceleration by kinetic Alfvén waves, resonant interaction with ion-cyclotron waves...) are likely candidates to explain this heating, and could contribute to the heating of the solar corona and acceleration of the fast solar wind. As each kind of wave-particle interaction leads to different heating rates as a function of the ion charge-to-mass ratio (q/m), the analysis of the ion temperatures of different minor ions of the corona is a key to solve the heating and acceleration mechanisms of the fast solar wind. We extended the work of Dolla et al. (2008, 2009) by using the Hinode/EIS spectrometer to measure the spectral line widths of coronal ions the above the solar limb. From the line widths we then derive the width of the kinetic distributions averaged along the line of sight, which is a combination of the ion temperature and any plasma motion like those induced by MHD waves. Our results confirm the trend of preferential heating of the ions: the lower the q/m, the higher the temperature. We compare this trend in coronal holes and quiet Sun regions and we also compare the temperatures of minor ions with those of the protons (as deduced from the asymptotic limit of the temperature at largest q/m) and of the electrons.

Funding: PEA/4000120800/4000120800

The record appears in these collections:
Royal Observatory of Belgium > Solar Physics & Space Weather (SIDC)
Conference Contributions & Seminars > Seminars
Royal Belgian Institute for Space Aeronomy
Solar-Terrestrial Centre of Excellence

 Record created 2019-04-05, last modified 2019-04-05