This is a proposal attempting to convert gamma-ray energy into electric energy via differentiated secondary electron generation by gamma rays interacting with two different metal components. The proposed systems consist of two different metal sheets, sandwiching an insulator material, which are arranged in either "roll" or "plate" geometry. Under gamma-ray irradiation, both types of systems produce electric currents that vary with the properties and geometrical structures of the metals. In this preliminary study, the maximum generated electric current and power for the roll system were 0.58 A and 0.093 W, respectively, with 0.01-mm-thick aluminum and 0.1-mm-thick stainless steel sheets.

The Monte Carlo N-Particle (MCNP) simulations performed in conjunction with the experimental study have shown that the electric current corresponds to the difference between the two metal components in terms of the number of electrons escaping the metals. The difference can be increased by optimizing the combination of thicknesses, the Z numbers of the two metal components, and the geometrical structures of the system, agreeing with the experimental study. These results strongly suggest that the electric currents in the proposed systems can be predicted on the basis of the simulation. Finally, we propose the application of an electric cell driven by a gamma-ray source and shielded by the electrodes themselves.