Nuclear Battery

(also atomic battery), a source of current that converts the energy released in the course of radioactive decay to electrical energy (seeRADIOACTIVITY).

Nuclear batteries are used chiefly in portable radios, wristwatches, hearing aids, and measuring instruments. They can be subdivided into two types, depending on the method of converting nuclear energy to electrical energy: batteries with direct charging of the electrodes, in which the charged particles escaping from one electrode (the emitter) accumulate on the other electrode (the collector), forming a potential difference, and batteries in which the kinetic energy of the emitted charged particles is converted to electrical energy through an intermediate medium—gas, liquid or solid. In the latter case, the battery utilizes the effects of the contact difference of potentials of the electrodes in an ionized gas and the electrochemical generation of energy from radical and molecular products formed under the action of radioactive emission on the electrolyte; it also makes use of semiconductor p-n junctions. The source of charged particles in a nuclear battery (beta particles, alpha particles, fission fragments) is provided either by radioactive isotopes or by nonradioactive elements, such as silver, which are activated in a nuclear reactor by neutron irradiation.