  The Micro Solar-Flare Apparatus (MiSolFA) is a compact X-ray imaging
spectrometer designed for a small 6U micro-satellite. As a relatively
inexpensive yet capable Earth-orbiting instrument, MiSolFA is designed to image
the high-energy regions of solar flares from a different perspective than that
of Solar Orbiter's STIX, operating from a highly elliptical heliocentric orbit.
Two instruments working together in this way would provide a 3-dimensional view
of X-ray emitting regions and can bypass the dynamic range limitation
preventing simultaneous coronal and chromospheric imaging. Stereoscopic X-ray
observations would also contain valuable information about the anisotropy of
the flare-accelerated electron distribution. To perform these types of
observations, MiSolFA must be capable of imaging sources with energies between
10 and 100 keV, with 10 arcsec angular resolution. MiSolFA's Imager will be the
most compact X-ray imaging spectrometer in space. Scaling down the volume by a
factor of ten from previous instrument designs requires special considerations.
Here we present the design principles of the MiSolFA X-ray optics, discuss the
necessary compromises, and evaluate the performance of the Engineering Model.
