What Is a Dosimeter?

An instrument that measures the dose of nuclear radiation received at a given time.

An instrument that measures the dose of nuclear radiation received at a given time.

Chinese name

Dosimeter

Also known as

Dosimeter

Function

Measuring received nuclear radiation

working principle

Chemical reactions caused by ionizing radiation

Introduction to dosimeters

Common dosimeters are: film dosimeter, thermoluminescence dosimeter and glass dosimeter. In order to monitor the spatial dose rate in radioactive workplaces, ionization chambers are often used. In recent years, semiconductor probes have also been frequently used. In addition, in large-scale production facilities, fixed alarm meters can be selected for continuous monitoring of dose rates. A system that uses chemical changes caused by ionizing radiation to determine the absorbed dose. The method of measuring the absorbed dose with a chemical dosimeter is collectively called the chemical dosimetry.

Dosimeter Related Information

Under the action of ionizing radiation, any chemical reaction that can be quantitatively analyzed can be used as a measurement system for chemical dosimetry. There are no fewer than dozens of chemical dosimeters that have been used or tried. In order to adapt to different dose ranges, it is necessary to accurately measure the absorbed dose of the irradiated object so that the components of the dosimeter and the irradiated object have equivalent electron density and atomic composition. Therefore, to determine the absorbed dose of biological materials, organisms and aqueous samples, the chemical dosing method of the aqueous system is often used; for a wider range of irradiated objects, a variety of gas, liquid and solid chemical dosing methods can be used.

Chemical dosimeters must be stable and reproducible before and after irradiation. It is best to have no post-irradiation effect or a short duration of post-effect duration. For an ideal chemical dosimeter, it is required that the yield of the radiolysis product as a measure of the degree of change is not affected by the dose rate, the type of radiation and the irradiation temperature, or has a small effect under certain conditions; the cumulative amount and absorption of reaction products There should be a linear relationship between the doses. The most representative and oldest in the aqueous solution dosage system is the ferrous sulfate dosimeter. Another widely used is cerium sulfate and cerium sulfate dosimeters, which can measure absorbed doses up to 2 × 106 grays.

In order to adapt to a variety of different dose ranges, different irradiated systems and different test requirements, the dose system used is also the electron spin resonance test system for alanine, colored or colorless plexiglass systems, and radiochromic dye solutions. Or membrane systems, triacetate membranes and various types of membranes or solid dosimeters. Although some of these systems are accompanied by chemical reactions with physical effects or a combination of chemical and physical methods when testing, such dosimeters are still widely used as chemical dosimeters.