X ray properties
1.Penetration is the ability of x-rays to pass through matter without being absorbed.X-rays can penetrate substances that are not visible through visible light.Visible light has a long wavelength,and some of its energy is very small.When it hits an object,some of it is reflected,most of which is absorbed by matter,and cannot pass through the object.X rays are not,because their wavelength is short and their energy is large,and only part of them is absorbed by matter,and most of them are through the gap of atoms,showing a strong penetrating ability.The ability of the X-ray to penetrate the material is related to the energy of the X-ray photon,the shorter the wavelength of the X-ray,the greater the energy of the photon and the stronger the penetration.The penetrating power of X rays is also related to the density of matter,the density of matter,the absorption of X rays,through little;Little density,little absorption,through much.The use of differential absorption allows for the differentiation of the density of bone,muscle,fat and other soft tissues.This is the physical basis of X-ray fluoroscopy and photography.
2.Ionizing substances,when irradiated by X rays,ionize electrons from the atomic orbitals,which is called ionization.Appear in the process of photoelectric effect and scattering,optoelectronics and recoil electrons from the atoms called an ionization,the process of the photoelectron or recoil electronic and other atoms collide in travel,cause the atom escape electron is called the secondary ionization.In solids and liquids.The positive and negative ions after ionization will soon be complex and not easy to collect.But it is easy to collect in the gas,and the amount of ionizing charge can be used to determine the X-ray exposure:the X-ray measuring instrument is based on this principle.Because of ionization,gases can conduct electricity;Certain substances can have chemical reactions;All kinds of biological effects can be induced in the organic body.Ionization is the basis of X-ray damage and treatment.
3.Fluorescence is invisible because the X-ray wavelength is very short.But its exposure to certain compounds such as phosphorous,platinum barium,zinc sulfide,cadmium cyanide,such as calcium tungstate,due to the ionization or excitation make atomic excited state,atoms return to ground state in the process,as a result of the valence electron energy level transition and the visible or ultraviolet radiation,this is fluorescent.The effect of X-rays on the fluorescence of matter is called fluorescence.The fluorescence intensity is proportional to the amount of X-ray.This effect is the basis for X-ray application in perspective.In X-ray diagnosis,this fluorescence can be used to make a screen,a sensitized screen,an input screen in the image intensifier.The fluorescence screen is used as an X-ray to observe the image of the X-ray through the human body,and the sensitized screen is used to enhance the film's sensitization.
4.The X-ray energy absorbed by the thermal action material,most of which is converted to heat,heats the object,which is the thermal effect.
5.Interference,diffraction,reflection,and refraction act in the same way as visible light.It is used in X-ray microscopy,wavelength determination and material structure analysis.
1.As with visible light,x-rays can sensitize film.Silver particles can be produced when x-rays are irradiated on film.The deposition causes the film to be"photosensitive".The strength of the film is proportional to the amount of X-ray.When X rays pass through the human body,because of the different density of the tissues of the human body,the absorption of X rays is different,and the sensitivity obtained on the film is different,so as to obtain X-ray images.This is the basis for the application of X-ray imaging.
2.Some substances,such as platinum cyanide,lead glass,crystal,etc.,after long exposure to X rays,the crystals dehydrate and change the color,which is called tinting.
When X ray irradiation to the biological organism,biological cells from being destroyed by inhibition,necrosis,even cause the body in different degree of physiological,pathological and biochemical changes,known as the biological effect of X ray.Different biological cells have different sensitivities to x-rays.Maple x-rays can be used to treat certain diseases,such as tumors.On the other hand,it can also harm the normal body,so it is necessary to protect the body.The biological effects of x-rays are ultimately caused by the ionization of x-rays.Because X ray has the above effect!Therefore,it has been widely used in industry,agriculture and scientific research,such as industrial inspection,crystal analysis,etc.In medicine,X-ray technology has become a specialized subject in the diagnosis and treatment of diseases and occupies an important position in medical and health care.