The effective dose equivalent dose absorbed dose

 Japanese nuclear radiation hazards seriously the environmental sector across the country were recently released to the public, nuclear radiation monitoring indicators, and publishing data out of micrograys (nGy), Gy (Gy), which people have been hearing these days Micro Sev, mSv is not the same, what is the difference between the two?

Fudan University professor of environmental science Chen Jianmin introduces the reader to the most commonly used radiation dose: absorbed dose, equivalent dose and effective dose.

Absorbed dose: refers to a unit mass of tissue or organ absorbed radiation of energy, the unit of absorbed dose Gy (Gy), 1Gy grant equivalent per kilogram of mass-energy radiation tissue or organ is 1 Joule.

Equivalent dose: the absorbed dose in tissue or organ average radiation power received multiplied by the weighting factor after the resulting product.

Effective dose: refers to the sum of human exposure to nuclear radiation dose. For example, if the air nuclear radiation equivalent to 1 mSv, while a person living in this environment 10 hours, for him, the effective dose is 1 times 10 to 10 mSv.

What is the weight of the radiation? After the nuclear radiation into the atmosphere, the air of different radiation effects of nuclear radiation on, for example, the right to neutron radiation weighting factor of 5 ~ 20, α radiation weighting factor is 20, equivalent dose unit is the millisievert (mSv ), micro-sievert. But in the general living environment status, in sunlight most of the X, γ and β rays, the radiation weighting factor is 1, therefore, in most cases, quite absorbed dose and dose equivalent, for example, the authorities detected some coastal areas of nuclear 0.001 Gy of radiation absorbed dose, equivalent dose is also shown as 0.001 mSv.

Title Source

"Gy" in the name comes from the father of the British physicist, radiation biology of Louis Harold Gy (Louis Harold Gray).

SV English as Sievert, named after the Swedish physicist Rolf biological Maximilian Sievert (Rolf Maximilian Sievert).

People's Republic of China national standards "Quantities and units" (GB 3100-93 and GB 3102.10-93) provisions, Sievert's Chinese name is called sievert legal unit item No. 10-52.a.