Overview of Astrophysical MeV-Gap Gamma Ray and Dark Matter Detection with GRAMS

Gamma-Ray and AntiMatter Survey (GRAMS), one of the NASA Physics of the Cosmos suborbital missions, is an experiment designed to detect astrophysical gamma rays falling within the MeV range of 0.1 to 100, called MeV-Gap, and also to serve as an indirect method for detecting dark matter. These MeV-gap gamma rays haven't been extensively studied due to limitations in existing instruments to detect them. GRAMS also has the potential to be the first to detect MeV gamma rays from evaporating Primordial Black Holes (PBHs) and neutron star mergers associated with gravitational waves, as well as from galactic neutron star merger remnants. Our focus is on the GRAMS detector design, which has a significant sensitivity improvement, more than an order of magnitude, in detecting MeV-gap gamma rays and is highly sensitive to antideuterons and antiheliums, aiding in the detection of dark matter annihilation or decay. Currently, we are building a small-scale liquid argon time projection chamber detector. I will be presenting the research and development status, including the preparation for the first prototype balloon flight in 2025/2026.