Overview of Radiation Types and Sources PJ Flashcards
what can radiation be categorized as?
ionizing and non-ionizing
radiation can be in the form of what three things?
particles, massless quanta, and disturbances in the medium itself
any form of radiation that possesses mass is termed what?
particulate (or corpuscular) radiation
what are three examples of particulate radiation?
alpha particles, beta particles, and neutrons
does particulate radiation possess mass?
yes
does particulate radiation possess charge
may (alpha, beta) or may not (neutron) possess charge
does particulate radiation travel less, more or equal to the speed of light?
less
what type of every does particulate radiation possess?
kinetic
what is the formula for kinetic energy?
1/2 mass x velocity ^2
alpha = __ AMU
neutron = __ AMU
beta or positron = __ AMU
alpha = 4 AMU
neutron = 1 AMU
beta or positron = 1/1840 AMU
what charge does alpha have?
2 positive charges
what charge does beta have?
1 negative charge
what charge does positron have?
1 positive charge
what does radiation with a finite range mean?
any shielding material thicker than the maximum range will stop ALL of the radiation particles, regardless of haw many are being emitted by the source
how do charged particles interact with orbital electrons?
through direct electrostatic collisions
what are the may direct electrostatic collisions result in?
ionization or excitation
what happens to the electron during ionization?
electron “ejected” from orbit
what happens to the electron during excitation?
electron raised to higher energy orbit
what do excited electrons give off when they revert to their ground state?
non-ionizing photons
what is the luminescence called when it is produced essentially only when the exciting radiation source is present?
fluorescence
what is the luminescence called that continues for some time after the source of exciting radiation is removed?
phosphorescence
what type LET does alpha have?
very high
what is the rate at which energy is deposited by radiation along the track that it follows through matter?
LET (Linear Energy Transfer)
what is used to compare ability of different types of radiation to produce biological effects?
RBE (Relative Biological Effectiveness)
what is the penetrating ability, external hazard, and internal hazard of alpha?
- low penetrating ability 2. no external hazard 3. significant internal hazard
what are fundamentally electrons that are emitted from a nucleus?
beta
what is the penetrating ability, external hazard, and internal hazard of beta?
- variable penetrating but relatively easy to shield 2. minimal to no external hazard from low energy (significant external hazard to shallow tissue depths from higher energy betas) 3. significant internal hazard
what is the ejected electron (the ionizing particle) called?
conversion electron
auger electrons are _____.
monoenergetic
what results in two 0.511 MeV photons that travel in opposite directions from one another?
annihilation
what concept does E = mc ^2 relate to?
Under appropriate conditions, mass can convert to energy, and vice-versa
