First data for abundance diagnostics with SPICE, the EUV spectrometer on-board Solar Orbiter

2021 ◽  
Author(s):  
Natalia Zambrana Prado ◽  
Éric Buchlin ◽  
Hardi Peter ◽  
Keyword(s):  
Remote Sensing ◽  
Solar Activity ◽  
Ionization Potential ◽  
Relative Abundance ◽  
Potential Effect ◽  
Spectral Lines ◽  
Field Of View ◽  
The Sun ◽  
First Ionization Potential ◽  
Euv Spectrometer

<p>Linking solar activity on the surface and in the corona to the heliosphere is one of Solar Orbiter’s main goals. Its EUV spectrometer SPICE (SPectral Imaging of the Coronal Environment) will provide relative abundance measurements which will be key in this quest, as different structures on the Sun have different abundances as a consequence of the FIP (First Ionization Potential) effect. From the 16th to the 22nd of November 2020,  the Solar Orbiter remote sensing checkout window STP-122 was carried out. During this period of observations, SPICE was lucky to catch a small AR in its field of view. We carried out abundance specific observations in order to provide relative FIP bias measurements with SPICE. Furthermore, data from other types of observations carried out during that same week allow us to identify the spectral lines that could be used for abundance diagnostics. We take the SPICE instrument characteristics into account to give recommendations regarding the types of studies to carry out to obtain such abundance measurements.</p>

scholarly journals Relative abundance diagnostics with SPICE, the EUV spectrometer on-board Solar Orbiter

2020 ◽  
Author(s):  
Natalia Zambrana Prado ◽  
Eric Buchlin ◽  
Hardi Peter
Keyword(s):  
Remote Sensing ◽  
Relative Abundance ◽  
Emission Measure ◽  
Potential Effect ◽  
Spectral Lines ◽  
Trace Back ◽  
First Ionization Potential ◽  
Inner Heliosphere ◽  
Euv Spectrometer

<p>With the launches of Parker Solar Probe and Solar Orbiter, we are closer than ever to linking solar activity on the surface and in the corona to the inner heliosphere. In this quest, relative abundance measurements will be key as different structures on the Sun have different abundances as a consequence of the FIP (First Ionization Potential) effect.</p><p>Comparing in-situ and remote sensing composition data, coupled with modeling, will allow us to trace back the source of heliospheric plasma. Solar Orbiter has a unique combination of in-situ and remote sensing instruments that will hopefully allow us to make such comparisons.</p><p>High telemetry will not always be available with SPICE (SPectral Imaging of the Coronal Environment), the EUV spectrometer on board Solar Orbiter. We have therefore developed a method for measuring relative abundances that is both telemetry efficient and reliable. Unlike methods based on Differential Emission Measure (DEM) inversion, the Linear Combination Ratio (LCR) method does not require a large number of spectral lines. This new method is based on optimized linear combinations of only a few UV spectral lines. We present some abundance diagnostics applied to synthesized radiances of spectral lines observable by SPICE.</p>

scholarly journals Monochromatic X-Ray Imagers of the Sun Based on the Bragg Crystal Optics

2021 ◽  
Vol 8 ◽  
Author(s):  
Anton A. Reva ◽  
Sergey V. Kuzin ◽  
Alexey S. Kirichenko ◽  
Artem S. Ulyanov ◽  
Ivan P. Loboda ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Corona ◽  
Spectral Lines ◽  
Coronal Plasma ◽  
The Sun ◽  
Spectral Filter ◽  
Crystal Optics ◽  
X Ray ◽  
Hot Plasma ◽  
Wide Range

Investigations of solar activity require information about plasma in a wide range of temperatures. Generally, researchers require observations from telescopes producing monochromatic images of coronal plasma with cool, warm, and hot temperatures. Until now, monochromatic telescopic imaging has been made only in the Mg XII 8.42 Å line with the Mg XII spectroheliograph on board CORONAS-I, CORONAS-F, and CORONAS-PHOTON satellites. The Mg XII spectroheliograph used Bragg crystal optics. Its design is based on two main principles: (1) to select the working wavelength and the crystal in such a way that reflection occurs at small incident angles; (2) to use the aperture of the mirror as a spectral filter. We believe that these design principles can be applied to other spectral lines. In this article, we will review the design of the Mg XII spectroheliograph and present our thoughts on how to apply these principles to the Si XIV 6.18 Å and Si XIII 6.65 Å lines. A combination of the monochromatic Mg XII 8.42 Å, Si XIV 6.18 Å, and Si XIII 6.65 Å images will help us to study the dynamics of the hot plasma in the solar corona.

scholarly journals Fe/O ratio behavior as an indicator of solar plasma state at different solar activity manifestations and in periods of their absence

2018 ◽  
pp. 33-58
Author(s):  
Геннадий Минасянц ◽  
Gennady Minasyants ◽  
Тамара Минасянц ◽  
Tamara Minasyants ◽  
Владимир Томозов ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Cosmic Rays ◽  
Ionization Potential ◽  
Solar Minimum ◽  
Geomagnetic Storms ◽  
Galactic Cosmic Rays ◽  
Ion Fluxes ◽  
Ion Energy ◽  
First Ionization Potential

We report the results of the investigation into plasma physical characteristics at various solar activity manifestations and in periods of their absence. These results have been obtained from quantitative estimates of the relative abundance of Fe/O ions in different energy ranges. Maximum values of the Fe/O ratio is shown to correspond to particle fluxes from impulsive flares for ions with energies <2 MeV/n (the most significant manifestation of the FIP effect). In particle fluxes from gradual flares, the Fe/O value decreases smoothly with ion energy and is noticeably inferior to values of fluxes in impulsive events. We have established that the properties of flares of solar cosmic rays indicate their belonging to a separate subclass in the total population of gradual events. Relying on variations in the abundance of Fe/O ions, we propose an xplanation of the solar plasma behavior during the development of flares of both classes. Magnetic clouds (a separate type of coronal mass ejections (CME)), which have regions of turbulent compression and are sources of strong geomagnetic storms, exhibit a relative composition of Fe ions comparable to the abundance of Fe in ion fluxes from gradual flares. We have found out that the Fe/O value can be used to detect penetration of energetic flare plasma into the CME body at the initial phase of their joint development and to estimate its relative contribution. During solar minimum with complete absence of sunspots, the Fe/O ratio during periods of “quiet” solar wind show absolutely low values of Fe/O=0.004–0.010 in the energy range from 2–5 to 30 MeV/n. This is associated with the manifestation of the cosmic ray anomalous component, which causes an increase in the intensity of ion fluxes with a high first ionization potential, including oxygen (O), and elements with a low first ionization potential (Fe) demonstrate weakening of the fluxes. As for particles with higher energies (Ek>30 MeV/n), the Fe/O increase is due to the decisive influence of galactic cosmic rays on the composition of impurity elements in the solar wind under solar minimum conditions. The relative content of heavy elements in galactic cosmic rays 30–500 MeV/n is similar to values in fluxes from gradual flares during high solar activity. During solar minimum without sunspots, the behavior of Fe/O for different ion energy ranges in plasma flows from coronal holes (CH) and in the solar wind exhibits only minor deviations. At the same time, plasma flows associated with the disturbed frontal CH region can be sources of moderate geomagnetic storms.

scholarly journals Fe/O ratio behavior as an indicator of solar plasma state at different solar activity manifestations and in periods of their absence

2018 ◽  
Vol 4 (1) ◽  
pp. 29-50
Author(s):  
Геннадий Минасянц ◽  
Gennady Minasyants ◽  
Тамара Минасянц ◽  
Tamara Minasyants ◽  
Владимир Томозов ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Cosmic Rays ◽  
Ionization Potential ◽  
Solar Minimum ◽  
Geomagnetic Storms ◽  
Galactic Cosmic Rays ◽  
Ion Fluxes ◽  
Ion Energy ◽  
First Ionization Potential

We report the results of the investigation into plasma physical characteristics at various solar activity manifestations and in periods of their absence. These results have been obtained from quantitative estimates of the relative abundance of Fe/O ions in different energy ranges. Maximum values of the Fe/O ratio is shown to correspond to particle fluxes from impulsive flares for ions with energies <2 MeV/n (the most significant manifestation of the FIP effect). In particle fluxes from gradual flares, the Fe/O value decreases smoothly with ion energy and is noticeably inferior to values of fluxes in impulsive events. We have established that the properties of flares of solar cosmic rays indicate their belonging to a separate subclass in the total population of gradual events. Relying on variations in the abundance of Fe/O ions, we propose an xplanation of the solar plasma behavior during the development of flares of both classes. Magnetic clouds (a separate type of coronal mass ejections (CME)), which have regions of turbulent compression and are sources of strong geomagnetic storms, exhibit a relative composition of Fe ions comparable to the abundance of Fe in ion fluxes from gradual flares. We have found out that the Fe/O value can be used to detect penetration of energetic flare plasma into the CME body at the initial phase of their joint development and to estimate its relative contribution. During solar minimum with complete absence of sunspots, the Fe/O ratio during periods of “quiet” solar wind show absolutely low values of Fe/O=0.004–0.010 in the energy range from 2–5 to 30 MeV/n. This is associated with the manifestation of the cosmic ray anomalous component, which causes an increase in the intensity of ion fluxes with a high first ionization potential, including oxygen (O), and elements with a low first ionization potential (Fe) demonstrate weakening of the fluxes. As for particles with higher energies (Ek>30 MeV/n), the Fe/O increase is due to the decisive influence of galactic cosmic rays on the composition of impurity elements in the solar wind under solar minimum conditions. The relative content of heavy elements in galactic cosmic rays 30–500 MeV/n is similar to values in fluxes from gradual flares during high solar activity. During solar minimum without sunspots, the behavior of Fe/O for different ion energy ranges in plasma flows from coronal holes (CH) and in the solar wind exhibits only minor deviations. At the same time, plasma flows associated with the disturbed frontal CH region can be sources of moderate geomagnetic storms.

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