What is the Gamma Constant measured in?

The Gamma Constant is a measure of the exposure rate from a radioactive source at a specific distance. It quantifies how much exposure (in terms of ionizing radiation) a person would receive from a certain amount of radioactivity over time and distance.

The correct choice indicates that the Gamma Constant is expressed in units of R cm/mCi per hr. In this context, "R" refers to roentgen, a unit used to measure exposure to ionizing radiation; "cm" indicates that the measurement is taken at a distance of one centimeter from the radioactive source; "mCi" refers to millicuries, a unit of radioactivity; and "hr" signifies that the measurement is based on an hourly rate.

This definition aligns with the practical applications and standard units used in radiation safety and dosimetry, facilitating safe handling of radioactive materials in medical and industrial settings. Understanding this measurement helps health physicists and radiologists assess the potential exposure related to specific radioactive isotopes, guiding safety protocols.