The Miniature X-ray Solar Spectrometer (MinXSS) CubeSats: spectrometer characterization techniques, spectrometer capabilities, and solar science objectives

摘要

The Miniature X-ray Solar Spectrometer (MinXSS) are twin 3U CubeSats. Thefirst of the twin CubeSats (MinXSS-1) launched in December 2015 to theInternational Space Station for deployment in mid-2016. Both MinXSS CubeSatsutilize a commercial off the shelf (COTS) X-ray spectrometer from Amptek tomeasure the solar irradiance from 0.5 to 30 keV with a nominal 0.15 keV FWHMspectral resolution at 5.9 keV, and a LASP-developed X-ray broadband photometerwith similar spectral sensitivity. MinXSS design and development has involvedover 40 graduate students supervised by professors and professionals at theUniversity of Colorado at Boulder. The majority of previous solar soft X-raymeasurements have been either at high spectral resolution with a narrowbandpass or spectrally integrating (broadband) photometers. MinXSS will conductunique soft X-ray measurements with moderate spectral resolution over arelatively large energy range to study solar active region evolution, solarflares, and the effects of solar soft X-ray emission on Earth's ionosphere.This paper focuses on the X-ray spectrometer instrument characterizationtechniques involving radioactive X-ray sources and the National Institute forStandards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility(SURF). Spectrometer spectral response, spectral resolution, response linearityare discussed as well as future solar science objectives.