X-ray machine editor
X-ray machine is to produce X-ray equipment, which mainly consists of X-ray bulb tube and X-ray machine power supply and control circuits, etc., while the X-ray bulb tube by the cathode filament (Cathod) and anode target (Anode) and vacuum glass tube, X-ray machine power supply can be divided into high-voltage power and filament power supply two parts, of which the filament power supply is used to heat the filament, high-voltage power supply of the high-voltage output are clamped to the cathode filament and anode target at both ends to provide a high voltage, the high voltage power supply and the high voltage power supply. Power supply can be divided into high voltage power supply and filament power supply, in which the filament power supply is used to heat the filament, the high voltage output of the high voltage power supply is clamped on the two ends of the cathode filament and the anode target respectively, to provide a high voltage electric field to make the filament active electrons accelerated to the anode target to form a high-speed electron flow, bombardment of the anode target surface, 99% of the conversion into heat, 1% due to the Compton effect to produce X-rays.
Chinese name
X-ray machine
X-ray discoverer
German physicist R?ntgen
X-ray wavelength
Approx. 0.001-100nm
X-ray machine inventor
Russell Reynolds
Medical scope of application
X-ray interventional Diagnosis, chest fluoroscopy, radiographs, etc.
Catalog
1 Principle and construction of X-ray machines
Discovery of X-rays Nature of X-rays X-rays in medicine A brief history of the development of medical X-ray equipment2 Role of large-scale X-ray machines
3 Technical parameters of X-ray machines
High-pressure generator X-ray tube holder Photographic flat bed Chest radiography frame4 Portable X-ray machine
Medical portable X-ray machine Industrial inspection X-ray machine Belt inspection X-ray machine5 Inventors
1 Principle and construction of X-ray machine edited
Principle and construction of X-ray machine
Nordin X-ray machine Principle diagram
The discovery of X-rays
In 1895, the German physicist R?ntgen (W. C. R?ntgen) in the study of the phenomenon of gas discharge in the cathode ray tube, with a embedded two metal electrodes (a called anode, a called cathode) sealed glass tube, the electrodes at the ends of the addition of several tens of thousands of volts of high voltage electricity, the use of pumping machine from the glass tube to pump out the air. In order to block the leakage of light (a kind of arc light) from the high-voltage discharge, a layer of black cardboard was placed over the glass tube. While conducting this experiment in a dark room, he happened to notice that two meters away from the glass tube, a piece of cardboard washed with a solution of barium platinum cyanide emitted bright fluorescence. Further tests with cardboard, boards, clothes and books about two thousand pages thick could not block this fluorescence. Even more surprisingly, when the fluorescent cardboard was held in the hand, the image of a hand bone was seen on the cardboard.
R?ntgen concluded that this was a kind of ray that was invisible to the human eye but could penetrate objects. Unable to explain its principle, unknown its nature, it borrowed the mathematical representation of the unknown number of "X" as a code name, known as "X" rays (or X-rays or X-ray for short). This is the discovery of X-rays and the origin of the name. This name has been used to this day. In honor of Roentgen's great discovery, it was named Roentgen rays.
The discovery of X-rays is of great significance in the history of mankind, and it opened a new path for natural science and medicine, for which R?ntgen was honored with the first Nobel Prize in physics in 1901.
Science is always in constant development, by R?ntgen and the repeated practice and research of scientists from all over the world, gradually revealing the nature of X-rays, confirming that it is a very short wavelength, a great deal of energy electromagnetic waves. Its wavelength is shorter than the wavelength of visible light (about 0.001 ~ 100nm, medical applications of X-rays wavelength of about 0.001. ~ 0.1nm), and its photon energy than the photon energy of visible light several tens of thousands to hundreds of thousands of times. Therefore, X-rays in addition to the general nature of visible light, but also has its own characteristics.
The nature of X-rays
(a) physical effects
1. penetration effect penetration effect is the X-rays through the material is not absorbed when the ability to X-rays can penetrate the general visible light can not be through the substance. Visible light because of its long wavelength, photons of its energy is very small, when shot to the object, part of the reflection, most of the material is absorbed, can not pass through the object; X-rays is not, because of its short wavelength, energy, shine on the material, only part of the material is absorbed, most of the interatomic space and through the performance of a very strong ability to penetrate the X-rays. The ability of X-rays to penetrate matter and the energy of X-ray photons, the shorter the wavelength of the X-rays, the greater the energy of the photons, the stronger the penetration of X-rays, X-rays penetration is also related to the density of the material, the density of the material, X-rays absorbed more through less; density of small, less absorbed, through more. The use of differential absorption of this nature can be different density of bone, muscle, fat and other soft tissues can be distinguished. This is the physical basis of X-ray fluoroscopy and photography.
2. Ionization of matter by X-ray irradiation, so that the nuclear electrons out of the atomic orbitals, this effect is called ionization. In the photoelectric effect and scattering process, the emergence of photoelectrons and recoil electrons from its atomic process called primary ionization, these photoelectrons or recoil electrons in the travel and other atomic collisions, so that the struck atoms escape electrons called secondary ionization. In solids and liquids. Ionized positive and negative ions will be quickly compounded, not easy to collect. But in the gas in the forget ionized charge is very easy to collect, the use of ionized charge of how much can determine the amount of X-ray exposure: X-ray measuring instrument is made according to this principle. As a result of ionization, gases can conduct electricity; certain substances can undergo chemical reactions; and various biological effects can be induced in organisms. Ionization is the basis of X-ray damage and treatment.
3. Fluorescence Due to the short wavelength of X-rays, it is invisible. But it irradiated to some compounds such as phosphorus, platinum barium cyanide, zinc cadmium sulfide, calcium tungstate, etc., due to ionization or excitation of atoms in the excited state, the atom back to the base state process, due to the valence electrons of the energy level of the leap and radiate visible light or ultraviolet light, which is fluorescence. x-rays to make the material fluorescence is called fluorescence. The intensity of fluorescence is proportional to the amount of X-rays. This effect is the basis for the use of X-rays in fluoroscopy. In X-ray diagnostic work using this fluorescence effect can be made into a fluorescent screen, sensing screen, image intensifier in the input screen and so on. The fluorescent screen is used for fluoroscopy to observe the image of X-rays passing through human tissue, and the intensifier screen is used for photography to enhance the light sensitivity of the film.