Radiation Physics & Principles Flashcards

Which type of radiation interaction with matter results in the complete absorption of an x-ray photon by an inner-shell electron, ejecting it from the atom?

Answer: Photoelectric effect

The photoelectric effect occurs when an x-ray photon is completely absorbed by an inner-shell electron, which is then ejected from the atom.

What is the unit of absorbed radiation dose in the SI system?

Answer: Gray

The Gray (Gy) is the SI unit of absorbed dose, equal to 1 joule of energy deposited per kilogram of tissue.

Which property of x-rays allows them to penetrate matter?

Answer: Short wavelength and high frequency

X-rays have short wavelengths and high frequencies, giving them enough energy to penetrate matter.

The quality of an x-ray beam is primarily controlled by which exposure factor?

Answer: kVp

kVp (kilovoltage peak) controls the energy (quality/penetrating power) of the x-ray beam.

Which phenomenon describes the decrease in x-ray intensity as the beam travels farther from the source?

Answer: Inverse square law

The inverse square law states that x-ray intensity is inversely proportional to the square of the distance from the source.

Which shell electron is most likely involved in the photoelectric interaction that produces characteristic radiation?

Answer: K-shell (innermost) electron

Characteristic radiation is produced when a K-shell electron is ejected and an outer-shell electron fills the vacancy, releasing a photon.