Physics and Interactions Flashcards
7 cards from real NRRPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Physics and Interactions flashcards as text
Internal conversion (IC) electrons are emitted with energies equal to:
Answer: The gamma-ray energy minus the electron's atomic binding energy
In internal conversion, the nuclear excitation energy is transferred directly to an orbital electron; the electron is ejected with energy equal to the gamma-ray energy minus its atomic binding energy.
Which interaction dominates for low-energy photons (<100 keV) in high-Z materials?
Answer: Photoelectric effect
The photoelectric effect dominates at low photon energies and is proportional to Z⁴–Z⁵, making it dominant in high-Z materials at energies below ~100 keV.
The specific ionization of a charged particle in air generally increases as the particle slows down near the end of its range, forming a region known as the:
Answer: Bragg peak
As heavy charged particles slow near the end of their range, the interaction cross section increases, producing a sharp maximum in ionization density called the Bragg peak.
A radionuclide decays by beta-minus emission. Which statement about the emitted beta particle energy spectrum is correct?
Answer: It is a continuous spectrum with a maximum energy (Emax)
Beta particles are emitted with a continuous spectrum from near zero up to Emax because the available decay energy is shared between the beta particle and the antineutrino.
The nuclear binding energy per nucleon is greatest for nuclides near which mass number?
Answer: A ≈ 56 (iron)
The binding energy per nucleon curve peaks around A = 56 (iron-56), which is why fusion of light elements and fission of heavy elements both release energy.
Coherent (Rayleigh) scattering of photons differs from Compton scattering in that it:
Answer: Scatters the photon with no energy transfer to the atom
In Rayleigh scattering, the photon is deflected by the atom as a whole with essentially no energy transfer; the wavelength (and energy) of the photon remains unchanged.
The dose equivalent (H) is calculated as:
Answer: H = D × Q, where D is absorbed dose and Q is radiation quality factor
Dose equivalent H = D × Q (in older ICRP terminology), where D is absorbed dose in gray and Q is the quality factor reflecting the relative biological effectiveness of the radiation type.