Техническое чтение для энергетиков. Бухарова Г.П. - 12 стр.

UptoLike

ВУЗ: 

УлГТУ | Ульяновск

Составители: 

Рубрика: 

14
producing units – is based on a discovery recorded already by the Curies around
1900, but neglected by scientists for nearly half a century. That was the observation
that radio-activity could produce electricity directly in certain materials. When, after
the Second World War, cheap radio-active sources–isotopes–became available the
idea was taken up at last. The first, somewhat crude 'atomic battery', as it was called,
was produced in 1954 by a research team in the laboratories of the Radio Corporation
of America: a little box containing a thin wafer of the isotope, strontium 90 – one of
the dangerous elements in radio-active 'fall-out' after H-bomb tests; it bombarded
with its particles a semi-conductor crystal, an adaptation of the transistor. The current
generated in the crystal by the radio-active emanation of the strontium was strong
enough to produce a buzzing noise in an earphone.
Isotopes for direct generation of electricity will be available in growing
quantities as the utilization of atomic energy spreads to more and more countries.
One of the major problems connected with nuclear power stations is the safe disposal
of radio-active waste; burying it, or dumping it into the sea, is not everywhere the
best means of getting rid of it. But when devices such as atomic batteries are mass
produced they will require great quantities of radio-active 'waste' products; they must,
of course, be made absolutely safe for everyday use.
How can we tell if we are the target of radio-active emanation? It is invisible
and inaudible, and we cannot feel it – unless and until we have received too much of
it and become ill. But there is a vital tool in our nuclear age, the Geiger counter in its
manifold forms, which measures radio-activity accurately. Invented by Hans Geiger,
a German physicist and one of Lord Rutherford's close collaborators, in the 1920's, it
is an ingenious instrument which can make any type of radiation, whether in the form
of particles or of electro-magnetic waves, visible and audible.
The Geiger counter consists of a metal cylinder filled with gas at low pressure;
two electrodes – one being the cylinder itself, the other a fine wire stretched along its
centre – are maintained at a large potential difference, usually about 1,000– 1,500
volts, but no spark is allowed to pass between them. Only when some subatomic
particle or unit of electro-magnetic radiation pierces the thin metal of the cylinder and
produces ionization (i. e. when the gas atoms become electrically charged), there is a
sudden discharge between the electrodes, and the potential drops for the fraction of a
second. This can be made either visible on a dial, or audible in a pair of headphones.
Frequently, simple counting devices such as telephone counters are attached to the
tube to register the number of incoming particles.
Geiger counters are being made and adapted for all kinds of purposes–light
ones for uranium prospecting; built-in types for atomic power stations and research
establishments; counters with warning signals for factory workers who have to handle
radio-active matter and whose hands and clothes have to be checked; counters which
can test human breath for traces of radon gas, and so on.
Finally, a new source of energy could be created by 'depositing' the heat of a
nuclear explosion deep underground and using it – just as volcanic heat is used in
some parts of the world – for the production of power. It has been estimated that an
atomic blast 3,000 feet underground in a suitable geological formation would produce

Страницы