The Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN) Instrument Concept

We outline a new instrument concept for a solar gamma-ray spectral imager, the Large Imaging Spectrometer for Solar Accelerated Nuclei (LISSAN). Models of solar coronal particle acceleration suggest that roughly equal amounts of energy may go into electrons and ions. However, while previous solar X-ray spectroscopic imagers have transformed our understanding of electron acceleration, they have typically been unable to image the gamma-ray emission produced by accelerated ions. LISSAN images at photon energies of 40keV-100MeV with greater sensitivity and imaging capability than its predecessors. This is achieved by deploying high-resolution scintillator detectors and indirect Fourier imaging techniques. LISSAN is expected to increase the total number of imaged solar ion acceleration events by 1-2 orders of magnitude and provide direct comparisons with the electron acceleration process. Without this, our understanding of solar particle acceleration will always be incomplete.