Coherent scatter will only occur...
at high energies
When the photon has energy greater than the electron binding energy
At low photon energies
After a previous interaction
The probability of compton scatter occurring is...
Is proportional to energy
Is proportional to density squared
Is proportional to electron density
Is inversely proportional to energy
What happens to the positron produced after pair production?
It travels through matter and excites and ionises atoms
It is absorbed by an x-ray photon
It will interact with the nucleus of an atom
It combines with an electron- annihilation
In a low energy compton scatter interaction, where is most of the energy deposited?
The initial photon
The ejected electron
Electrons produced in all interactions...
Will have the same energy as the initial photon
Will produce a photoelectron
Will carry some energy from the initial photon
Transferred to the medium by ionisation or excitations
Can result in x-ray production
How much energy must a photon have to undergo photoelectric interactions?
1.022meV
More than the binding energy of a bound electron
More than the binding energy of the k shell
0.511meV
The probability of pair production is...
Is proportional to energy squared
Is inversely proportional to z
Is proportional to z
What is the Linear Attenuation Coefficient (LAC)?
Fraction of photons interacting per gram of material
Fraction of photons interacting per unit thickness of attenuator
Fraction of electrons interacting relative to Z of material
To undergo a pair production interaction, how much energy must the initial photon have?
Enough to overcome the binding energy of the electron
1.022kV
What is produced in the photoelectric effect?
An electron and a positron
The photon is diffracted
Nothing
An electron is ejected and a new photon produced.
The probability of photoelectric absorption....
Is proportional to z sqaured.
Is proportional to z cubed.
Is inversely proportional to energy cubed.
Is proportional to energy cubed.
