Computer-Based Study of Secondary Emission Cell (SEC) Efficiency Compared to That of a Vacuum-Type Direct Collection Cell

The concept of directly collecting secondary electrons created by beta emission through an electrical insulator has been proposed as an attractive low-voltage nuclear battery termed a secondary emission cell (SEC). In this paper, a MATLAB computer simulation of an SEC is conducted using Mott scattering, the Penfold–Katz slowing approximation, Bethe's ionization loss expression, and energy and momentum conservation. The goal of the simulation is to compare the efficiency of an SEC to that of a vacuum direct collection cell. It is found that the SEC efficiency is typically ≦1%. Energy losses in the insulator prevent it from having an efficiency advantage over a vacuum direct collection cell which offers higher efficiencies, especially at high voltages. However, operational simplicity and ease of construction still make the SEC attractive for some applications.