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Explain how X-Rays are produced

      

Explain how X-Rays are produced

  

Answers

Moraa
X-rays are produced when fast moving electrons are suddenly stopped by a metal target. At the time of their discovery by a German Physicist Roentgen, their nature was unknown and hence their name x-rays. Generally, x-rays are uncharged electromagnetic radiations of short wavelength and high penetrating ability (power).
X-rays are produced in an x-ray tube:
Current in the filament emits electrons at the cathode by thermionic emission. These electrons are then attracted towards the anode by the high potential difference that exists between the cathode and anode. On striking the target, the electrons transfer their kinetic energy to the metal target. About 99.5% of this energy is converted to heat at the target and only 0.5% of the energy is responsible for the production of x-ray radiations.
As such, the material of the target must be one that has a high melting point like molybdenum or tungsten. The anode should also be a good thermal conductor like copper so as to ensure efficient dissipation of heat.
Further cooling at the anode is enhanced by a circulation of oil around the anode and the presence of cooling fins.
In some tubes, the target is made in such away to rotate so as to change the point of impact and thus reduce wear and tear.
The target is inclined at an angle to direct the x-rays out of the tube. The glass tube is also evacuated to prevent interference with the electron beam before reaching the target. The cathode is concave in shape to focus the emitted electrons to the target. The high potential difference is used to accelerate the emitted electrons towards the anode.
The x-ray tube is well shielded using lead which absorbs any stray rays thereby protecting the user.

OR

They are produced by modified discharge tubes called X-ray tubes. The cathode is in the form of a filament which emits electrons on heating. The anode is made of solid copper molybdenum and is called the target. A high potential difference between the anode and the cathode is maintained (10,000 v to 1,000,000 or more) by an external source. The filament is made up of tungsten and coiled to provide high resistance to the current. The electrons produced are changed into x-rays on hitting the anode and getting stopped. Only 0.2% of the energy is converted into x-rays. Cooling oil is led in and out of the hollow of the anode to maintain low temperature. The lead shield absorbs stray x-rays.
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Moraa orina answered the question on April 12, 2018 at 06:32

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