Radiation Safety Lectures 2 & 3

3 basic quantities of measurement

length, time, mass

derived quantities

quantities formed from a combination of basic qualities, such as volume, mass, density, and velocity

4 special quantities for radiation

exposure, absorbed dose, effective dose, and radioactivity

3 cardinal principles of radiation protection

time, distance, and shielding

relationship between time and radiation exposure

direct relationship; increase in time increases radiation exposure

relationship between distance and radiation exposure

indirect relationship; increasing distance decreases radiation exposure

relationship between shielding and radiation exposure

indirect relationship[; increasing shielding decreases radiation exposure

inverse square law

decrease in radiation intensity is inversely proportional to the square of the distance from the source

half-value layer (HVL)

the thickness of absorbing material necessary to reduce x-ray intensity to half of its original value

high half-value layer (HVL)

indicates a more penetrating beam and a lower attenuation coefficient

electromagnetic energy

energy traveling through space with a combination of electric and magnetic fields

visible spectrum colors acronym

ROY G BIV (red, orange, yellow, green, blue, indigo, and violet) w

wave equation formula

C = v x λ (velocity equals frequency times wavelength)

x-rays vs. gamma rays origin

x-rays are emitted from the electron cloud, while gamma rays originate from inside the nucleus

radiopaque structures

structures that absorb x-rays, such as bone

radiolucent structures

structures that transmit x-rays, such as lung tissue and soft tissue p

photon definition

smallest quantity of any type of electromagnetic energy, having no mass and traveling at the speed of light