A novel design of the MeV gamma-ray imaging detector with Micro-TPC

A new type of MeV gamma-ray imaging detector in the energy band from 0.2 to 30 MeV, based on a gaseous time projection chamber with Micro Pixel Chamber (Micro-TPC), is proposed. This detector consists of a gas chamber and a scintillation camera. The Micro Pixel Chamber (μ-PIC) has pixel type anodes and cathodes with 400 μm pitch, which enables it to measure the fine tracks of electrons or positrons in Compton scattering or pair creation. The scintillation camera measures the positions and energies of Compton-scattered gamma-rays, electrons and positrons by pair creation. Using information from both the gas chamber and scintillation camera, the incident gamma-rays can be reconstructed event-by-event with high angular resolution. Simulation of the detector performance and the status of the prototype are reported.