Photon Interaction Basics
Ionization and ___ results in energy transfer.
What is excitation?
You need to know this physical quantity in order to convert linear attenuation coefficient to mass attenuation coefficients.
Don't be so dense.
What is the density?
For the photoelectric effect, the mass attenuation is proportional to (Z/E)? to this power.
What is 3 (or cubic)?
Heavy particles have a higher rate of energy loss per unit distance partly due to these 2 physical properties the particles have.
That is stuff is electric!
What are mass and charge?
Not a narrow beam attenuation, but a __ beam attenuation.
What is a broad beam?
Electrons, protons, and alpha particles are know as these types of ionizing radiation.
Don't be indirect in your answer.
What is directly ionizing radiation?
The atomic attenuation coefficient requires knowledge of the number of atoms, No, the (mass) attenuation coefficient, and this.
Don't sleep on me bro.
What is the atomic number, Z?
This is a rare kind of photon interaction, like pair-production, but requires a higher minimum threshold photon energy and creates 3 particles.
What is triplet production?
Dose from neutrons are primarily due to recoiling protons from hydrogen and recoiling heavy nuclei from other elements, and these types of disintegrations.
What are nuclear disintegrations?
The photon energy of annihilation radiation from pair production.
What is 0.511 MeV?
A type of indirect ionizing radiation that emanates from clinical linear accelerators AFTER the target and flattening filter beam.
What are photons?
For a photon beam traversing a material, the fraction of photon energy transferred into kinetic energy of charged particles per unit thickness of absorber is given by what kind of energy [?] coefficient?
What is the energy TRANSFER coefficient?
This describes the kind of photons that leave the interaction site after a photoelectric interaction.
Be discrete with your answer.
What are mono-energetic photons?
As proton beam energy increases, so does the location of this.
Don't be shy.
What is the depth of the Bragg peak?
This type of photon interaction has a 'sweet spot' or peaks ~30 keV to ~30 MeV in water.
What are Compton interactions?
The fluence rate is the ratio of fluence and what?
What is the time?
dN / dt
The energy absorption coefficient and energy transfer coefficient are different by this factor.
You are loosing your glow, my friend.
What is the fractional loss in energy due to radiative losses?
This number is the minimum energy of a photon to interact via pair production.
What is 1.02 MeV?
Protons are about as heavy as these other nuclear particles.
What are neutrons?
Arthur was his first name. He won a Nobel prize.
NWA is Straight Outta here.
Who is Compton?
This is what happens to the half value layer estimate if the absorber thickness increases and beam becomes more penetrating.
What is get larger / beam hardening?
(i.e., HVL (thin absorber) < HVL (thicker absorber) )
Coherent scattering is also known as this, named after a famous physicist.
What is Rayleigh Scattering?
Of Rayleigh/Coherent, photoelectric, Compton, and pair production, this type of interaction does not contribute to dose.
What is Rayleigh/Coherent scattering?
Lead is an efficient absorber of photons, but NOT an efficient absorber of these particles.
The answer is free of charge.
What are neutrons?
The effective atomic number of water.
What is Zeff water=7.51?