Production of X-Rays

Conditions Necessary for Production of X-Rays

• Must have a source of electrons (heating up filament)
• Filament made of tungsten is heated up causing electrons to be boiled off

Thermionic emmision (Edison effect) – is the boiling off of electrons e-

(X rays are produced in a highly evacuated glass bulb, called an X-ray tube, that contains essentially two electrodes—an anode made of platinum, tungsten, or another heavy metal of high melting point, and a cathode. When a high voltage is applied between the electrodes, streams of electrons (cathode rays) are accelerated from the cathode to the anode and produce X rays as they strike the anode. )

• To increase the acceleration of e- you increase the Kv (increase the potential difference)
• When electrons hit the target(anode) they are decelerated causing kinetic energy to be released as heat and x-rays
• To make this system more efficient you put it in a vacuum
• Cooling of the target is necessary / oil bath
• The greater the Kv the greater the energy of the x-rays

diode - an anode and a cathode

  Two types of radiation produced: from the production of x-rays:

Brehmstraluung Radiation – is radiation produced from the deceleration of electrons by hitting the target

Characteristic Radiation – unwanted radiation

• Scatters aound
• Low level radiation produced by the material that the target is made from,   it is characteristic of that material,   the inner orbit electrons of the target get excited and change energy states
• You can determine characteristic radiation by the target material that is used

*there is a widespread spectrum of energy (radiation) released from an x-ray tube, only 1/3 of the usable radiation is at peak!!