Why is the same power X - ray machine, especially the small power X - ray machine based on perspective, using a fixed anode compared with a rotating anode?
1, using X ray machine fixed anode X ray tube continuous working time is greatly higher than that of the X - ray machine rotating anode X ray tube; as everyone knows, X ray tube in X rays, only about 1% of the energy converted to X radiation, while more than 99% of the energy converted into heat energy gathered in the anode rake surface while facing the heat, the anode harrow bearing capacity is limited, if the heat cannot be transmitted, when the heat accumulation of more than X ray tube anode capacity, anode surface will be damaged to harrow, leading X ray machine damage, so the conductivity of X ray tube anode surface energy level of harrow that will directly determine the pros and cons of X X-ray machine. As we all know, there are three main types of heat transfer, conduction, convection and radiation. Among the three heat conduction modes, the most efficient way is conduction, followed by convection, and finally radiation. Rotating anode X ray tube anode shaft in the vacuum glass tube to rotate at high speed, isolated from the outside world, so the heat is not through the anode conduction shaft, at the same time, because of the X ray tube is a high vacuum glass tube, so it is impossible for convection heat conduction, heat transfer mode only when the temperature rises to rake face a certain extent, the heat radiation to the target surface X ray tube glass tube wall, and then pass out through the glass wall, so the heat efficiency is very low, although the general rotating anode target surface thermal volume is large, but because the heat can not transfer out, with the increase of time, heat accumulation will continue to increase and when the heat is accumulated to a certain extent, the instrument will automatically shut down, to protect and prevent damage to the instrument, so the rotating anode X ray machine for shorter working hours. Fixed anode anode rake face, so the core can be directly extended to rake vacuum glass tube, when the heat generated when the electron beam bombardment target surface, heat can be timely to the X-ray tube through the anode harrow core conduction, distributed to the oil, so the cooling efficiency is extremely high, so that the anode target surface remains relatively low the temperature of this instrument can work continuously for a long time, so the X ray machine fixed anode X ray tube continuous working time is much higher than that of the rotating anode X ray machine;
2, under the same conditions, the same photography focus size, by using X ray imaging machine X ray machine quality fixed anode X ray tube is better than using the rotating anode X ray tube; X ray produced by a high speed electronic flow meets the material blocking occurred in conversion of energy to produce the fixed anode rake face, ray the direction of electron beam bombardment surface is always a rake to, so ray energy is strong, good uniformity, so the image quality is better, and the rotating anode target surface of high-speed rotation, so some rays will also face the direction of rotation with the anode harrow generating deflection, the ray energy decreased uniformity reduced, so that the the decline in the quality of imaging.
3, using the fixed anode X ray machine reliability, X ray tube service life is much higher than that of the X ray machine rotating anode X ray tube; fixed anode X ray tube anode structure is relatively simple, static, not easy to damage, so good reliability, long service life, and the rotating anode X ray tube structure and control more the complex, so easy to damage, the failure rate is relatively high, relatively poor reliability, relatively short life;
4, under the same condition, using X ray machine fixed anode X ray tube than X ray machine with rotating anode X ray tube is more economical and practical; the fixed anode X ray tube production process is relatively simple, the production difficulty is small, the production cost is low, and the rotating anode X ray tube production process is relatively complex, the difficulty of production large, high production cost, so under the same condition, the fixed anode X ray tube rotating anode X ray tube is more economical and practical.
5, using fixed anode X-ray machines X X ray tube use and maintenance cost is low; because the fixed anode X ray tube is low cost, such as X-ray tube failure, maintenance and replacement costs are low, so using X ray machine X ray tube anode and maintenance costs will be significantly lower than the use of X ray machine rotating anode X - ray tubes.
In summary, the use of X-ray machine fixed anode X ray tube in the heat dissipation performance, image quality, reliability, continuous working time, use cost is much better than that of X ray machine rotating anode X ray tube, so in the same power X ray machine, especially small power X ray machine needs continuous work in perspective for the Lord for a single, continuous work for a long time, but the actual use of power is not the instantaneous heat capacity is not high, so the use of X ray machine practical performance of the fixed anode X ray tube is far greater than the use of X X-ray machine rotating anode X - ray tubes. But the high-power X ray machine is mainly based on photography. Because the time of photography is very short, but the instantaneous power is larger and the instantaneous heat is larger. So we must use the rotating anode X ray tube with large melting amount.