In this article we will discuss about the design of high voltage and low voltage atomic batteries with the help of suitable diagrams.
Design of High Voltage Atomic Battery:
Fig. 9.28 shows the schematic diagram of a high voltage atomic battery.
It consists of an inner spherical electrode on the surface of which is deposited a powerful beta emitting (i.e., fast electrons) substance. This is surrounded by another spherical condenser and the inner surface of this condenser becomes negatively charged. This acts as the outside electrode and is properly insulated at the opening. The inner and, outer electrodes become the – ve and + ve terminals of the battery.
Sr90 isotope can be used since its half-life is 28 years. These batteries perform independent of the temperature unlike the accumulators whose electrolyte freezes at low temperatures. These also supply a very steady constant potential.
This has yet to be developed on a commercial scale.
Design of Low Voltage Atomic Battery:
Fig. 9.29 shows a low voltage battery.
In this Sr90 (beta emitter) is deposited on the surface of a semiconductor (germanium or silicon) at one end and the other end is having a metallic collector. The semiconductor has the characteristic of undirectional current flow.
The fast electrons pass through the semiconductor and strike the metallic disc at the other end and the two ends of the semiconductor become the – ve and + ve terminals of the battery. The power produced by this battery is a few microwatts at a potential difference of 1/10 volt. This power is sufficient to feed a small radio.