The unit of measurement of radiation. Units of measuring ionizing radiation

Since the middle of last century in science it's a new word - radiation. Her discovery made a revolution in the minds of physicists around the world and allowed some to drop the Newtonian theory, and make bold assumptions about the structure of the Universe, its formation and our place in it. But it's all for specialists. Ordinary people only sigh and try to put together such disparate knowledge on the subject. Complicates the fact that the measurement of radiation there are quite many and they are all eligible.

Terminology

The First term, which is to meet, – it is, in fact, radiation. The so-called process radiation any substance of tiny particles, such as electrons, protons, neutrons, helium atoms, and others. Depending on the type of particle properties of radiation are different from each other. See the radiation or the decay of substances to more simple, or with their synthesis.

Units of radiation – this is conditional concepts, which indicate how many elementary particles is released from a substance. At the moment physics operates seven different units and their combinations. This allows us to describe various processes occurring with the matter.

Radioactive decay - an arbitrary change in the structure of unstable nuclei by releasing particles.

Decay Constant – is a statistical concept that predicts the probability of failure of the atom for a certain period of time.

Half-life – the length of time over which splits half of the total amount of substance. Some of the elements he calculated a minute, and others – for years and even decades.

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What is measured by radiation

Units of radiation is not the only that are used to evaluate the properties of radioactive materials. In addition they used such values as:
- activity radiation source;
- flux density (the number of ionizing particles per unit area).

In addition, there is a difference in the description of the effects of radiation on living or inanimate objects. So, if the substance is inanimate, then it applies to concepts:

- the absorbed dose;
- exposure.

If the radiation effect on living tissue, then use the following terms:

- equivalent dose;
- effective dose;
- the dose rate.

The Units of radiation are, as mentioned above, the conditional numerical values adopted by the scientists to facilitate calculations and construction of hypotheses and theories. Perhaps that is why there is no single common unit of measurement.

Curie

One of the units of measurement for radiation is the Curie. It does not apply to the system (does not belong to the SI system). In Russia it is used in nuclear physics and medicine. The activity of the substance will equal one Curie if in one second it will occur 3.7 billion radioactive decays. That is to say that one Curie is equal to three semistar million billion becquerels.

This is the number of happened due to the fact that Marie Curie (who introduced in science the term) conducted their experiments on radium and had based its rate of decay. But over time physicists have decided that the numerical value of this unit to better bind the other to Becquerel. It is possible to avoid some errors in mathematical calculations.

In Addition to Curie, you can often find a multiple or decimal fraction of a unit, such as:
- megacurie (equal to 3.7 times 10 to the 16 extent becquerels);
- kilocurie (3.7 thousand billion becquerels);
- MCI (37 million becquerels);
- microcuries (37 becquerels thousands).

With this unit you can Express volume, surface, or specific activity of a substance.

Becquerel

A Unit of radiation dose Becquerel is a system and belongs to the International system of units (SI). It is the most simple, because the activity of radiation in one Becquerel means the substance takes just one radioactive disintegration per second.

It received its name in honor of Antoine Henri Becquerel, a French physicist. The name was approved at the end of the last century and still in use today. As this is a fairly small unit, to indicate activity use the metric prefixes: kilo-, Milli-, micro -, and others.

In recent years, along with the becquerels were used such common units like curies and Rutherford. One Rutherford is equal to one million becquerels. In the description of a volume or surface activity can meet the designation Becquerel per kilogram Becquerel per metre (square or cubic) and their various derivatives.

X-ray

A Unit of radiation x-ray also is not a system, though used universally to refer to the exposure dose received, gamma radiation. One roentgen is equal to a dose of radiation at which one cubic centimeter of air at standard atmospheric pressure and zero temperature carries a charge equal to 3.3*(10*-10). This is two million ion pairs.

Despite the fact that according to the legislation of the Russian Federation, most non-si units may be used, an x-ray is used in the labeling of the dosimeters. But they will soon cease to be used as a more practical thing was to record and calculate all in Grays and sieverts.

Happy

Unit of measurement of radiation rad is outside C and equals this amount of radiation at which one gram of the substance is passed one-millionth of a Joule of energy. That is one happy – it is 0.01 Joule per kilogram of matter.

Material which absorbs energy, can be like living tissue, and other organic and inorganic substances and substances: soil, water, air. As an independent unit glad was introduced in 1953 and in Russia has the right to be used in physics and medicine.

Gray

This is another unit of measurement of radiation level, which is recognized by the International system of units. It reflects the absorbed dose of radiation. It is believed that the matter had received a dose of one gray, if the energy that was transferred by radiation is one Joule per kilogram.

This unit got its name in honor of the English scientist Lewis gray and was officially introduced to science in 1975. According to the rules, the full unit name is written in small letters, but its abbreviation – with big. One gray equals one hundred rad. In addition to the simple units, science is also used multiples and sub-multiples of their equivalents, such as kilogray, megagray, decigray, centigray, MicroGray and others.

Sievert

The Unit of measure of radiation sievert is used to denote effective and equivalent doses of radiation and is also in SI units as gray and Becquerel. Used in science since 1978. One sievert is equal to the energy consumed kg of tissue after exposure of one gray of gamma rays. The name of his unit was named after Rolf Sievert, a scientist from Sweden.

According to the definition, sieverts and Grays are equal, that is, equivalent and absorbed dose have the same dimensions. But the difference is still there. In determining equivalent dose it is necessary to consider not only the quantity but also the other properties of radiation, such as wavelength, amplitude, and which particle it represents. Therefore, the numerical value of the absorbed dose multiplied by the quality factor of the radiation.

For example, under all other equal conditions the absorbed effect of alpha particles is twenty times stronger than the same dose of gamma radiation. In addition, it is necessary to consider the tissue factor, which shows how organs react to radiation. Therefore the equivalent dose is used in radiobiology and effective – health (regulation of radiation exposure).

Solar constant

There is a theory that life on our planet appeared due to solar radiation. The unit of measurement of radiation from a star-calories and watts, divided by unit time. It was decided because of the amount of radiation from the Sun is determined by the amount of heat that is provided to the objects, and the intensity with which it acts. To Earth reaches half million share of the total amount of emitted energy.

Radiation from stars distributed in space with the speed of light and our atmosphere will get in the form of rays. The spectrum of this radiation is quite wide – from “white noise”, that is, radio waves to x-rays. The particles also get together with radiation – protons, but sometimes can be electrons (if the energy was large).

The Radiation received from the Sun, is the driving force of all living processes on the planet. The amount of received energy depends on the time of year, position of a star above the horizon and atmospheric transparency.

The Effects of radiation on living beings

If the same in terms of characteristics of living tissue to irradiate different types of radiation...