Cosmic MeV gamma-ray observation presents a valuable diagnostic tool for studying the universe. The "MeV gap", ranging from about 0.1-100 MeV, has not yet been observed with the same sensitivity as neighboring energies, leaving questions like the origin of gamma-ray and positron excesses toward the galactic inner region. Traditional nonlinear imaging methods using Compton circle superposition and coded mask apertures can’t effectively discriminate background from signal. This sensitivity gap is limited by the angular resolution of gamma rays and the tracking of Compton scattered electrons, crucial for background suppression.
       To address these challenges, we propose a new mission concept: the MeV Gamma-ray Telescope (MeGaT), consisting of an advanced Micromegas-based high-pressure TPC and a pixel readout CZT detector. MeGaT offers excellent angular resolution and background rejection through precise 3D trajectory reconstruction and accurate energy resolution for both Compton scattered electrons and gamma rays. The MeGaT prototype, a 30cm cubic design operating at 3-5 bar gas pressure, will be discussed in this presentation. Along with its design, performance expectations, and the current status of its R&D will be also discussed.

Micromegas,Gamma Telescope,Time Projection Chamber