Ionizing Radiation Protection Flashcards
Definition of Isotones
Rev. 1
Same number of neutrons, Different number of Protons (e.g. 3H, 4He)
Low LET for electrons set in motion by Co-60 vs. High LET alpha
Co-60 emits a 2 ~1.25 MeV gammas. Low LET for electrons set in motion ~ 0.25 Kev/micrometer. High LET alpha is 1000x that. So a 2 MeV alpha will set electrons in motion at 250 KeV/micrometer
Absorption by a medium of kinetic energy from a high energy charged particle through excitation and ionization
Rev. 1
Definition of “Dose”
Define ‘Secular Equilibrium’
Rev. 1
When the half life of the parent is very much greater than that of the daughter half life. After ~7 half lives, the activity of the daughter = activity of the parent
Radioactive decay is affected only by
Rev. 1
Conditions within the nucleus
Approximate diameter of an atomic nucleus
Rev. 1
1E-12 cm
Approximate diameter of an atom
Rev. 1
1E-8 cm
Most predominate constituent of primary cosmic radiation
Rev. 1
Protons
Cosmic radiation accounts for approximately ____ mrem per year at sea level?
Rev. 1
- This number roughly doubles for every 2000 meters increase in altitiude. e.g. Denver ~50 mrem
Numerical value of Quality Factor (Q) is based partly on:
Rev. 1
Biological effect and judgment. Q is not experimentally determined.
KERMA is the sum of the initial kinetic energy of all charged particles liberated by:
Rev. 1
Uncharged ionizing radiation
The Stopping Power for electrons _____ as the atomic number of the absorber _____
Rev. 1
decreases, increases. Stopping Power ~ hinderance
Bremmsstrahlung predominantly occurs at energies greater than:
Rev. 1
1 MeV
Average energy of a positron emitted during positron decay:
Rev. 1
2/5 or 0.4 of its max
For an alpha particle to penetrate the dead layer of skin, it must have an energy of at least:
Rev. 1
7.5 MeV
Define Internal Conversion as it related to an atom’s decay
Rev. 1
The nucleus transfers its energy to an orbital electron, which is then ejected
Name and list the multiple factor for the 3 naturally occurring decay series and the 1 artificially produced series
Rev. 1
Actinium (4n+3), Uranium (4n+2), Neptunium (4n+1) artificially produced, and Thorium (4n). Think A.U.N.T.
SI unit for energy
Rev. 1
Joule. English system is Erg
Isobar
Rev. 1
Same Atomic Mass Number e.g. 14C, 14N
Isotope
Rev. 1
Same number of Protons e.g. 32P, 33P
Isomer
Rev. 1
Same Mass and Atomic Number, different Meta-Stable states e.g. 99mTc and 99Tc
Definition of a Hot Particle
Rev. 1
Discrete radioactive fragment that is insoluble in water and is less than 1mm.
Minimum mass of material which sustains a nuclear chain reaction
Rev. 1
Critical Mass. Made up of fissile isotope, isotope enrichment, geometry, presence and types of moderator and reflector material.
Primary isotopes of natural uranium whose natural abundances are 99.23729, 0.7206, and 0.0057
Rev. 1
U-238, U-235, and U-234