Three generations of the Miniature X-ray Solar Spectrometer (MinXSS) have
flown on small satellites with the goal "to explore the energy distribution of
soft X-ray (SXR) emissions from the quiescent Sun, active regions, and during
solar flares, and to model the impact on Earth's ionosphere and thermosphere".
The primary science instrument is the Amptek X123 X-ray spectrometer that has
improved with each generation of the MinXSS experiment. This third generation
MinXSS-3 has higher energy resolution and larger effective area than its
predecessors and is also known as the Dual-zone Aperture X-ray Solar
Spectrometer (DAXSS). It was launched on the INSPIRESat-1 satellite on 2022
February 14, and INSPIRESat-1 has successfully completed its 6-month prime
mission. The INSPIRESat-1 is in a dawn-dusk, Sun-Synchronous Orbit (SSO) and
therefore has 24-hour coverage of the Sun during most of its mission so far.
The rise of Solar Cycle 25 (SC-25) has been observed by DAXSS. This paper
introduces the INSPIRESat-1 DAXSS solar SXR observations, and we focus the
science results here on a solar occultation experiment and multiple flares on
2022 April 24. One key flare result is that the reduction of elemental
abundances is greatest during the flare impulsive phase and thus highlighting
the important role of chromospheric evaporation during flares to inject warmer
plasma into the coronal loops. Furthermore, these results are suggestive that
the amount of chromospheric evaporation is related to flare temperature and
intensity.Comment: 43 pages including 19-page Appendix A, 8 figures, 7 table