An exposure of 1 roentgen corresponds to which charge release?

The exposure of 1 roentgen corresponds to a charge release of 2.58 × 10^-4 C/kg. This value is derived from the definition of the roentgen, which is a unit of measurement for ionizing radiation exposure in air. Specifically, one roentgen is the amount of radiation required to produce a specific quantity of ionization in air, leading to the release of a charge.

At standard temperature and pressure (NTP), the relationship between exposure in roentgens and charge in coulombs per kilogram is defined based on measurements of the ionization produced in dry air. The established conversion factor of 2.58 × 10^-4 C/kg indicates the amount of electrical charge released when 1 roentgen of gamma or X-ray radiation is absorbed in air under standard conditions.

This knowledge is essential for medical dosimetrists as it aids in calculating dose delivery and ensuring precise radiation treatment planning. Understanding how exposure relates to charge release allows professionals to accurately assess the interaction of radiation with matter and correlate exposure with potential biological effects.