X-ray radiation

X-ray radiation, from the point of view of physics,this is electromagnetic radiation, the wavelength of which varies in the range from 0.001 to 50 nanometers. It was discovered in 1895 by the German physicist V. K. Röntgen.

By nature, these rays are relatedsolar ultraviolet. In the spectrum of the solar ray, the longest are radio waves. They are followed by infrared light, which our eyes do not perceive, but we feel it as warmth. Next come the rays from red to violet. Then - ultraviolet (A, B and C). And immediately behind him are X-rays and gamma rays.

X-rays (X-rays) can bewas obtained in two ways: when the charged particles pass through it in a substance, and when electrons move from higher layers to internal ones, when energy is released.

In contrast to visible light, these rays are very long, so they can penetrate through opaque materials without reflecting, not refracting and not accumulating in them.

Brake radiation is easier to get. Charged particles emit electromagnetic radiation when braking. The greater the acceleration of these particles and, consequently, the sharper deceleration, the more X-ray radiation is generated, and the wavelength of its waves becomes smaller. In most cases, in practice resort to the production of rays in the process of electron deceleration in solids. This allows you to control the source of this radiation, avoiding the danger of radiation exposure, because when the source is turned off, the X-ray radiation completely disappears.

The most common source of such radiation- X-ray tube. The radiation emitted to it is not homogeneous. There is a soft (long-wave) and hard (short-wave) radiation. Soft is characterized by being completely absorbed by the human body, so this x-ray radiation harms twice as much as the hard one. With excessive electromagnetic radiation in the tissues of the human body, ionization can lead to damage to cells and DNA.

A tube is an electrovacuum device with twoelectrodes - a negative cathode and a positive anode. When the cathode is heated, electrons evaporate from it, then they are accelerated in the electric field. When they collide with the solid substance of the anodes, they begin inhibition, which is accompanied by the emission of electromagnetic radiation.

X-ray radiation, whose properties are widelyused in medicine, is based on obtaining a shadow image of the object under study on a sensitive screen. If the organ to be diagnosed is illuminated by a beam of rays parallel to each other, the projection of the shadows from this organ will be transmitted without distortion (in proportion). In practice, the radiation source is more similar to a point source, so it is located at a distance from the person and from the screen.

To get an X-ray, a personis placed between the X-ray tube and the screen or film acting as radiation receivers. As a result of irradiation in the picture, bone and other dense tissues manifest themselves as obvious shadows, look more contrasted against the background of less expressive areas that transmit tissues with less absorption. On X-rays, a person becomes "translucent".

Spreading, x-ray radiation canscattered and absorbed. Before absorption rays can pass hundreds of meters in the air. In dense matter, they are absorbed much faster. Human biological tissues are heterogeneous, so the absorption of rays depends on the density of the tissues of the organs. Bone tissue absorbs rays faster than soft tissue, because it contains substances that have large atomic numbers. Photons (separate particles of rays) are absorbed by different tissues of the human body in different ways, which allows to obtain a contrast image with the help of X-rays.