What is the SI unit for absorbed dose?

The SI unit for absorbed dose is the Gray (Gy). This unit quantifies the amount of energy deposited by ionizing radiation in a material, particularly biological tissues. One Gray is defined as the absorption of one joule of radiation energy per kilogram of matter. This measurement helps in understanding the potential biological effects of radiation exposure.

In contrast, the Sievert (another option) is a unit that measures the biological effect of radiation, accounting for the type of radiation and its effects on human tissue, while the rem is an older unit equivalent to the Sievert but not used in the SI system. The rad is a non-SI unit that was historically used to measure absorbed dose, but it has largely been replaced by the Gray in modern usage. Therefore, the Gray is recognized as the standard unit for absorbed dose in the context of radiation protection and medical applications.