Finals | Electron-Target Interaction Flashcards
Electromagnetic radiation is also capable of transferring energy to an atom by this process
Excitation
Electrons in an atom are moved to a higher energy state without actually being removed from the atom
Excitation
Process of adding or removing an electron from an atom
Ionization
Total number of ion pairs produced by both primary and secondary ionization events per unit of track length along a charged particle track.
Specific ionization (S.I.)
The energy of motion
Kinetic Energy
Kinetic Energy Symbol
KE
Kinetic Energy Unit
Joules (J)
Kinetic Energy Formula
KE= (1/2)mv^2
Electrons travelling from cathode to anode
Projectile Electron
It interacts with the orbital electrons or nuclear field of target atoms
Projectile Electron
Projectile electron interacts with the (1) or (2) of (3)
- orbital electrons
- nuclear field
- target atoms
Three Effects of Projectile Electron
o Production of heat
o Formation of characteristics x-rays
o Formation of bremsstrahlung x-rays
Reasons for anode heat
Constant excitation & return of outer-shell electrons
Increases directly with increasing x-ray tube current & kVp
Anode Heat
Relations under anode heat
↑ AH, ↑ mA (Current)
↑ AH, ↑ kVp (Voltage)
Efficiency of X-ray Production
*It is independent of the tube current
*It increases with increasing kVp
Emitted when an outer-shell electron fills an
inner-shell void
Characteristic Radiation
An interaction with the inner-shell of a target atom
Characteristic Radiation
X-rays resulting from electron transition to the K shell
K X-rays
X-rays resulting from electron transition to the L shell
L X-rays
Only x-rays useful for imaging
K-characteristic x-rays of tungsten
It is produced when a projectile electron is slowed by the nuclear field of a target atom nucleus
Bremsstrahlung Radiation
An interaction with the nuclear field of a target atom
Bremsstrahlung Radiation
What bremsstrahlung radiation is also known as
“slowed down radiation”
It results from braking of projectile electrons by the nucleus
Bremsstrahlung Radiation
It results when the projectile electrons loses all its KE & simply drifts away from the nucleus
High-Energy Bremsstrahlung X-ray
It results when the
projectile electrons are
barely influenced by the
nucleus
Low-Energy Bremsstrahlung X-ray
Source of scattered radiation
patient
Source of leakage radiation
protective housing
Source of useful beam
window
