Diagnosing transient plasma status: from solar atmosphere to tokamak divertor

Abstract

This work strongly exploits the interdisciplinary links between astrophysical (such as the solar upper atmosphere) and laboratory plasmas (such as tokamak devices) by sharing the development of a common modelling for time-dependent ionisation. This is applied to the interpretation of solar flare data observed by the UVSP (Ultraviolet Spectrometer and Polarimeter), on-board the Solar Maximum Mission and the IRIS (Interface Region Imaging Spectrograph), and also to data from B2-SOLPS (Scrape Off Layer Plasma Simulations) for MAST (Mega Ampère Spherical Tokamak) Super-X divertor upgrade. The derived atomic data, calculated in the framework of the ADAS (Atomic Data and Analysis Structure) project, allow equivalent prediction in non-stationary transport regimes and transients of both the solar atmosphere and tokamak divertors, except that the tokamak evolution is about one thousand times faster.

Nonequilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind (Invited Review)

“…This different response to transient ionization for the two ions may be directly compared with IRIS observations investigating the behavior of the two lines Si iv 1349Å and the O iv 1401Å and the changes of their intensities during a flaring event with respect to a quiet region (Giunta et al, 2016). Assuming that in the quiet Sun region both ions are in ionization equilibrium, whereas the rapid variations of plasma conditions due to a transient event, such as a flare, lead to departure from ionization equilibrium, then the following relation is derived for each line (Giunta et al, 2016):…”

“…Assuming that in the quiet Sun region both ions are in ionization equilibrium, whereas the rapid variations of plasma conditions due to a transient event, such as a flare, lead to departure from ionization equilibrium, then the following relation is derived for each line (Giunta et al, 2016):…”

“…Observed ratios between the intensities of the flaring region, I AR , and the quiet region, I QS , as a function of time for Si iv 1394Å (black points) and O iv 1401Å (red points). From Giunta et al (2016). c SISSA.…”

Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}

“…This different response to transient ionization for the two ions may be directly compared with IRIS observations investigating the behavior of the two lines Si iv 1349 Å and the O iv 1401 Å and the changes of their intensities during a flaring event with respect to a quiet region (Giunta et al, 2016). Assuming that in the quiet Sun region both ions are in ionization equilibrium, whereas the rapid variations of plasma conditions due to a transient event, such as a flare, lead to departure from ionization equilibrium, then the following relation is derived for each line (Giunta et al, 2016):…”

“…Non-equilibrium/equilibrium population ratios as a function of the loop length for O iv (top panel) and Si iv (bottom panel). FromGiunta et al (2016). c SISSA.…”