What is the unit of radiation?

Release time:

2021-05-27

Radiation units are divided into two categories: activity units and radiation dose units, both of which are promulgated by the International Commission on Radiation Units and Measurements (ICRU) and are known as International System Units (SI units).

Activities

The number of times a radionuclide decays spontaneously per unit time, the decay rate, is called radioactivity. The unit of activity is "beque", abbreviated Bq, defined as: 1 beque (Bq) = 1 decay/second

Beque is used to represent the intensity (decay rate) of a radiation source, such as Cobalt 60.

Another commonly used old unit is "curie": 1 curie (Ci) = 3.7 × 10 bq (Bq)10.

Absorbed dose, D

The radiant energy (joules) absorbed per unit mass of a substance (kg) is called the absorbed dose. The unit of absorbed dose is "gray", abbreviated Gy, which is defined

1 Grey (Gy) = 1 J/kg

The average absorbed dose per hour is called the absorbed dose rate, and the units are ash/hour (Gy/h), milliGy/hour (mGy/h), and microGy/hour (μGy/h). To

Equivalent can, HT

Different types of radiation (α,β,γ, neutrons) irradiate the human body. Although the human body has the same absorbed dose, it will cause different harmful phenomena. To this end, radiation weighting factors (Q) are determined for different types of radiation, which represent different degrees of biological damage to human tissue caused by different radiation.

The equivalent dose is the product of the human body absorbed dose and the radiation weighting factor, which already contains the meaning of radiation harm to the human body. Its units are "Sievert", abbreviated "Xi", abbreviated Sv, and defined:

H (Severt) = D (Grey) × Q T

There are also millisieverts (mSv) and microsieverts (μsv). We performed a chest x-ray and the chest tissue received a dose of approximately 0.1 mSv. It can be seen from the radiation weighting factor q that although the alpha particles have weak penetration, they are very harmful to health. If isotopes of radioactive alpha particles such as uranium 235 are eaten into the body, they will cause greater damage to the tissues in the body.

effective dose (effective dose),E

Due to the different sensitivity of various tissues and organs of the human body to radiation, although the equivalent dose received is the same, the risk (probability) of health loss (cancer or bad genetics) is different, that is to say, different tissues and organs are damaged by the same radiation. Thus, a "tissue weighting factor" (WT) is established to represent the probability of health loss for each tissue and organ that receives radiation. To

If the equivalent dose (HT) of each tissue and organ is added to the product of its weighting factor, it becomes the effective dose (E). E stands for total body radiation dose, which is used to assess the risk of radiation that may affect our health, also in sievert (Sv).

What is radiation?

Common measurement methods for measuring radiation

What is radiation?

Common measurement methods for measuring radiation