Absorbed radiation dose

Absorbed radiation dose is a measure of the energy deposited by ionizing radiation in a unit mass of material, typically expressed in units of gray (Gy). It is a key concept in radiation protection, radiology, and radiotherapy.

Definition

The absorbed radiation dose is defined as the energy imparted by ionizing radiation to matter per unit mass. The SI unit of absorbed dose is the gray (Gy), which is defined as one joule of energy deposited per kilogram of material. The non-SI unit rad is sometimes also used, with 1 rad equivalent to 0.01 Gy.

Measurement

Measurement of absorbed dose is a complex process, as it depends on the energy of the radiation and the types and proportions of energy deposition events. It is usually determined by dosimetry, using devices such as dosimeters, ionization chambers, and thermoluminescent dosimeters.

Applications

In radiation protection, the absorbed dose is used to assess the risk of radiation-induced cancer and genetic damage. In radiology and radiotherapy, it is used to quantify the amount of radiation delivered to a specific tissue or organ, and to plan and monitor treatment.

See also

• Equivalent dose
• Effective dose (radiation)
• Radiation poisoning
• Radiation therapy