Sievert Sievert The sievert (symbol: Sv) is a derived unit of ionizing radiation dose in the International System of Units (SI) and is a measure of the health effect of low levels of ionizing radiation on the human body. The sievert is of importance in dosimetry and radiation protection, and is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation. The sievert is used for radiation dose quantities such as equivalent dose and effective dose, which represent the risk of external radiation from sources outside the
Ionizing radiation swelling, material creep, and embrittlement. Ionizing radiation can also accelerate existing chemical reactions such as polymerization and corrosion, by contributing to the activation energy required for the reaction. Optical materials darken under the effect of ionizing radiation. High-intensity ionizing radiation in air can produce a visible ionized air glow of telltale bluish-purplish color. The glow can be observed, e.g., during criticality accidents, around mushroom clouds shortly after a nuclear explosion, or inside of a damaged nuclear reactor like during the Chernobyl disaster. Monatomic fluids, e.g. molten sodium, have no chemical bonds to break and no crystal lattice to disturb, so