safety
what happens to amplitude after scatter?
it decreases.
What type of absorption occurs in the Photoelectric interaction?
total absorption of the x-ray photon
Why is the Photoelectric effect important for imaging?
Imaging cannot occur without absorption
What is another name for Coherent scatter?
1. Classical scatter.
2. Thompson scatter
3. Raleigh scatter
4. unmodified scatter
Is there any energy exchanged during the Coherent scatter interaction?
no energy is exchanged.
During the Compton interaction, ________enters, and a __________leave?
1. one photon enters
2. a scattered photon and ejected electron leave
what happens during the Photoelectric interaction?
incident x-ray photon interacts with an inner-shell electron (k-shell) and ejects the electron.
what is the Photoelectric interaction responsible for in patients?
Biologic damage.
What does Coherent scatter mean in terms of photon energy?
the photon is "Unmodified", meaning no change in energy
What happens to the photon after the Coherent scatter interaction?
changes direction with no loss of energy
what is the maximum number of times an X-ray photon can be scattered before losing its energy?
twice.
what must be true about the incident photons energy for a Photoelectric interaction to occur?
it must be equal to or Greater Than the electrons binding energy of the K-shell electron.
1. rate
2. intensity
3. dose
at what energy levels does Coherent scatter occur?
at very low x-ray photon energy levels
X-rays that undergo Coherent scattering contribute only to _________?
patient skin exposure
What is another name for the Photoelectric interaction?
Absorption.
What happens to the energy of the incident photon in a Photoelectric interaction?
all of the energy is transferred to the ejected electron (photoelectron).
the Photoelectric interaction is the primary source of __________?
patient radiation exposure
Approximately what percentage of x-rays undergo classical scattering at 70 kVp?
3%
What is the SI unit equivalent for Rad?
Gray (Gy)
Where does the Photoelectric effect occur?
in the patient
The K-shell vacancy is filled by an______?
outer shell electron.
How many particles enter and exit during a Photoelectric interaction?
one photon enters; one photoelectron exits.
What happens during Coherent scatter?
1. incident photon interacts with target atom and excites it.
2. no orbital electrons are ejected, and no ionization takes place.
What is the SI unit equivalent for Rem?
Sievert (Sv)