A Portable Electric Generator

To convert heat directly into electricity was one of the main tasks of scientists. The usual way was to produce electricity by means of generators and get their power from steam¹ or water turbines. Now the generator converting heat directly into elec­tricity has been developed. It is small in size and can produce only a small amount of energy. One can use this generator as a source of power for instruments carried in earth satellites. The generator weighs 2.3 kg, it has a diameter of 12 cm and a height of 14 cm. It can convert radiation from a radio-active material — Polonium 210— into heat, equivalent to 5 watts of electricity. It has no moving parts and operates by means of thermo-couples². A thermo-couple is made up of semiconduc­tors (two different metals that are good conductors of electricity but bad conductors of heat). To produce current one should heat these two metals and connect a wire to the two open ends³. The amount of energy to be released by a radio-active material is calculated in terms of half-lives.

Polonium 210 has a half-life of 140 days. It means that at the end of 140 days the radio-activity of polonium decreases, and the electrical power produced by it decreases, too, from 5 watts to 3 watts. Many other radio-active materials can be used instead of⁵ polonium.

Пояснения к тексту

1. steam — пар

2. thermo-couples — термо-пары

3. open ends — неизолированные концы

4. half-lives — периоды полураспада

5. instead of — вместо

XII. Переведите, пользуясь словарем:

Portable Reactors

Nuclear scientists all over the world devote much time to the problem of making reactors lighter and more compact than those which we have now. This is especially important for the countries with big and sparsely populated Arctic regions. To supply diesel oil to the remote Arctic station is very difficult. To provide such Arctic stations with a source of light and heat, the scientists have made the Low Power Reactor. This reactor supplies enough energy to light 300 cottages or heat 30 cottages. It is a highly specialized reactor. Instead of producing heat that goes to a turbogenerator, this reactor produces steam in its own core. The Low Power Reactor is made portable because it is intended for use at remote stations. Its components to be easily taken apart and reassembled are light in weight. It is a simple matter to fly the reactor parts to any place and then assemble them where the reactor is to be used.