Monday, June 27, 2011

History of the discovery of X-ray

X-rays were first discovered by German physicist Wilhelm C. Roentgen on November 8, 1895. At that Roentgen work using tubes.
Crookes in his lab at the University of Wurzburg. He observed a green glow on the tube which previously attracted the attention of Crookes. Roentgen then try to close the tube with black paper in the hope that no visible light can pass. But after closing it turns out there is still something that can pass. Roentgen-ray Concluding that there are invisible rays that can break through the black paper.
At the time of Roentgen turn the power source cathode ray tubes for research, he found that there is a kind of fluorescent light on the screen that made daribar ium platino cyanida who happened to be nearby. If the power source turned off, the light glow is gone. Roentgen quickly realized that some kind of invisible rays that have emerged from the cathode ray tube.

Because never before known, then the ray is given the name X-rays. But to appreciate his services in this invention, there is often X-rays were also called Roentgen rays. We call it the X-ray beam
Green flame seen by Crookes, and Roentgen rays finally known that it was none other than light waves emitted by glass walls on the tube when electrons hit the wall, as a result of the dismantling of electricity through the gas remaining in the tube. At the same time it stimulates the atomic electrons in the glass to release the electromagnetic waves are very short wavelengths in the form of X-rays. Since then physicists have known that X-rays can be produced when an electron with a very high-speed crash into atoms.
Tempted by an accidental discovery, the investigation focused on the Roentgen X-rays. From the investigation that he get that X-rays to casting various kinds of chemicals. X-rays can also penetrate various materials that can not be penetrated by ordinary visible light that is already known at the time. In addition, Roentgen also could see the shadow of his hand bone on a fluorescent screen by placing a hand between cathode ray tubes and screens. From the results of subsequent investigation found that X-rays are propagating traveling straight and is not deflected by either electric field or magnetic field. For the services in finding and studying the Roentgen X-rays, then in 1901 he was awarded the Nobel Prize Physics Division for the first time given in this field. The discovery of X-rays were able to deliver to the occurrence of a fundamental change in medicine. In the normal medical, X-rays can be used for diagnosis and therapy. With the discovery of X-rays, the information about the human body became easily available without the need to perform surgical operations.
X-rays can be formed when charged particles such as electrons by atomic nuclei style influences material decelerates. X-ray which is nothing but an electromagnetic wave that is formed through a process called X-ray bremsstrahlung. X-rays are formed in this way has the highest energy equal to the kinetic energy of charged particles at the time of the slowdown.
If initially there is a beam of electrons moving into the material with the same kinetic energy, electrons may interact with atoms of that at the time and place vary. Therefore, the next electron beam usually consists of electrons that have kinetic energy is different. When in a time of slowdown and cause X-rays, X-rays that occur generally has an energy that varies according to the kinetic energy of electrons at the time of formation of X-rays and also depend on the direction they emit.
X-ray beam that is formed is very low-energy according to energyelectrons at the time cause X-rays, but there are almost equal-energy electron kinetic energy when the electrons enter the material. It said X-ray beam that is formed through this process have nirfarik energy spectrum. X-rays can also be formed in the process of moving electrons from atoms to higher energy levels leading to a lower energy level, for example, in the process of advanced photoelectric effect. X-rays formed in this way has the same energy with the energy difference between the two levels of energy-related. Because this energy is typical for each type of atom, light is formed in this process is called the characteristic X-rays, X-ray group thus has farik energy. X-ray characteristics that arise by migration of electrons from one energy level to the trajectory k, called the X-ray K lines, while leading to the trajectory l, and so on. Bremsstrahlung X-rays can be produced through the plane X-rays or particle accelerators.
Basically, the X-ray machine consists of three main parts, namely X-ray tube, high voltage source which distribute electrical voltage on both electrodes in the X-ray tube, and the regulator unit. Part X-ray machine which is the source of radiation is X-ray tube. In plane X-ray tube is usually made of glass materials have filaments which act as cathode and a target that acts as an anode. Plane X-ray tube made vacuum for electrons originating from the filament is not hindered by air molecules in its journey toward the anode. Filament in the Heat by low-voltage electric current (If) a source of electrons. If the bigger the filament current, filament temperature will be higher and result in more and more electrons are released per unit time.
Electrons are released by the filaments drawn to the anode by a potential difference large or high voltage between cathode and anode units supplied by high voltage source (potential cathode few dozen to several hundred kV or MV lower than the anode potential), these electrons hit the material generally target atomic number and high liquid drip (eg tungsten) and there bremsstrahlung process. Especially in high-energy particle accelerator or a few electrons, accelerated particles can be somewhat distorted and smashed into a wall, giving rise to bremsstrahlung on the wall. Potential difference or voltage between two electrodes determines the maximum energy of X-rays are formed, while the X-ray flux depends on the number of electrons per unit time that reach the anode of the last field is called a flow tube It is of course dependent on the filament current It. However, within certain limits, the tube voltage can also affect the flow tube. Flow tube in a plane X-ray systems are usually only have this level of magnitude in the milliampere (mA), in contrast to the large filament current in amperes level.


X-rays can be produced by a set of tools that desebut plane X-ray X-ray machine is widely used in the health sector for diagnostic and therapeutic purposes and in industry, among others, for radiography. X-rays were first discovered by German physicist Wilhelm Conrad Roentgen on November 8, 1895. At that Roentgen work using Crookes tube in his lab at the University of Wurzburg.
The process of making images of human anatomy with X-rays can be performed on the surface of photographic film. Images are formed because of differences in the intensity of X-rays on the film surface after the absorption of some X-rays by any part of the human body. The body's absorption of X-rays depends strongly on the content of the elements that exist in the organ. Human bones that are dominated by elements of Ca has a high ability to absorb X-rays. Because absorption is the X-rays that pass through the bone will give the shadow image on a different movie than the shadow image of the organs that contain only air as the lungs ato water as soft tissue in general.
source : http://www.sman1liwa.sch.id/index.php?option=com_content&view=article&id=61:sejarah-penemuan-sinar-x-serta-cara-kerjanya&catid=43:artikel-guru&Itemid=41

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