X-ray Tube Flashcards
X-ray produced
Fast-moving electrons must undergo sudden and violent changes in direction
What happens to the energy of electrons when they hit the anode?
1% is converted into X-rays, and 99% is converted into heat.
Key components of a modern X-ray tube
Tube housing
Glass envelope
Vacuum
Cathode
Anode
Two types of X-ray tubes
Stationary-anode
Rotating-anode tubes
Two functions of the X-ray tube housing.
Radiation protection
Electrical protection
Two functions of the tube housing
Thermal protection
Physical protection
Why is a vacuum required in the X-ray tube?
To allow the anode and cathode to function efficiently
Material that is commonly used for the glass envelope and why?
Pyrex for its ability to withstand high temperatures
Role of the cathode in the X-ray tube
It is the source of electrons in the X-ray tube
Two components of the cathode
A coiled tungsten filament and a focusing hood or cup
Thermionic emission
The release of electrons from the surface of a material when it is heated
What temperature does tungsten exhibit thermionic emission?
Around 2000°C
What material is the anode typically made of and why?
Tungsten for its high melting point and ability to conduct heat and electricity.
Two designs of anodes
Stationary anode
Rotating anode
Line focus principle
A method to produce a small effective focal spot while spreading heat over a larger area
