Chapter 9 - The X-Ray Tube Flashcards
What is the minimum temperature required for thermionic emission to occur in the filament?
2000 degrees Celsius
What is the “space charge effect”?
A state of equilibrium where there is a constant number of electrons hovering in the electron cloud around the filament.
What is the focal spot?
The area where the electron beam strikes the anode
How long are the small and large focal spots?
SMALL - 0,5-0,6mm
LARGE - 1.0-1.2mm
What is electron density?
the ratio of the number of electrons an atom contains to the volume of space that it occupies
What is the line-focus principle?
the effective focal spot that is projected towards the patient’s body is SMALLER than the area the electrons strike on the anode
Where is the glass envelope thinnest?
the “window” where the focal spot is directed
