Among other types of electromagnetic radiation the gamma-rays differ in extraordinary small wavelength. For this reason at this radiation corpuscular properties are strongly expressed, and here wave – in much smaller degree. Interaction of gamma-rays with substance can lead to formation of ions.
Shortly about gamma radiation
Gamma radiation is a stream of the photons having high energy of so-called gamma quanta. The sharp border between x-ray and gamma radiation is not defined. On a scale electromagnetic an ox gamma-rays border on X-rays. They occupy the range of much higher energy.
If the radiation of quantum occurs in nuclear transition, it is carried to gamma radiation. And if in interaction of electrons or at the time of transitions to an atomic cover – that to x-ray. But this division is very conditional, radiation quanta with identical energy among themselves do not differ.
Gamma-rays are let out upon transitions between the excited conditions of atomic nuclei, at commission of nuclear reactions, at disintegrations of elementary particles, at a deviation of charged particles in electric and magnetic fields.
Gamma-rays were opened by Paul Villar, the French physicist. There was it in 1900 when the scientist investigated radium radiation. The name of radiation was used for the first time by Ernest Rutherford in two years. Later the electromagnetic nature of such radiation was proved.
Gamma radiation and its properties
The difference of gamma radiation from other types of electromagnetic beams is that it does not contain charged particles. Therefore gamma-rays do not deviate in magnetic or electric field. They are characterized by considerable penetration. Quanta of gamma radiation cause ionization of separate atoms of substance.
When passing gamma-rays through substance there are following effects and processes:
- photoeffect;
- Compton effect;
- nuclear photoeffect;
- effect of formation of couples.
Now for registration of gamma-rays use special detectors of ionizing radiation. They can be semiconductor, gas or scintillation.
Where gamma radiation is applied
Areas of application of gamma quanta are very different:
- gamma-radiography (quality control of products);
- conservation of products;
- sterilization of fish, meat, grain (for increase in a period of storage);
- processing of medical materials and the equipment for the purpose of sterilization;
- radiation therapy;
- measurement of levels;
- measurements in geophysics;
- measurement of distances from the lowered spacecrafts to a surface.
Impact of gamma radiation on an organism
Impact of gamma radiation on a biological organism can cause chronic or even sharp radiation sickness. Degree of a disease will depend on the apprehended dose of radiation and duration of influence. Separate effects of radiation can quite lead to development of oncological diseases. However in certain cases the directed radiation in gamma quanta is capable to stop growth of the cancer and other quickly sharing cells.
The substance layer can serve as protection against this type of radiation. The efficiency of such protection is defined by thickness of a layer and parameters of density of substance and also depends on the content in substance of heavy-nuclei. Protection consists in absorption of quantum of radiation at its passing through material.
Space beams are considered as the main source of gamma radiation. The gamma background getting on the earth possesses very large supply of energy. Beams of such look are capable to damage living cells, they lead to ionization circulation. The destroyed cages are capable to turn healthy components of the neighbors into poisons subsequently.
Unfortunately, the person has no special mechanism capable to signal about impact on gamma radiation fabrics. Therefore the person can receive a deadly dose of radiation and not understand it.
The haematogenic system is most sensitive to influence of gamma quanta, exactly there are most quickly sharing cages. At radiation the system of digestion, lymph nodes, the reproductive system, structure of DNA also strongly suffer.
Getting into deep structure of a chain of DNA, gamma-rays initiate process of mutations. At the same time the natural mechanism of heredity completely gets off. Doctors far are capable to define not at once why at the patient the health worsens. The reason of it is the long hidden period of changes and ability of radiation to accumulation of harmful action at the level of a cage.