Thermoluminescent dosimeter

Thermoluminescent dosimeter (TLD) is a passive radiation detection device that measures ionizing radiation exposure by storing energy deposited by radiation in a sensitive crystal. The stored energy is then released as light when the crystal is heated, with the intensity of the light being proportional to the radiation dose received. TLDs are commonly used in medical, nuclear, and industrial applications.

Principle of operation

The principle of operation of a TLD is based on the excitation of electrons in a crystal lattice by ionizing radiation. The excited electrons are trapped in defects in the crystal lattice, where they remain until the crystal is heated. The heating process releases the trapped electrons, which return to their ground state and emit light in the process. The intensity of the light is proportional to the radiation dose received by the crystal.

Types of TLDs

There are several types of TLDs, including lithium fluoride TLDs, calcium fluoride TLDs, and aluminum oxide TLDs. Each type of TLD has its own characteristics, such as sensitivity to different types of radiation, dose range, and fading characteristics.

Applications

TLDs are used in a variety of applications, including medical dosimetry, environmental monitoring, and personal dosimetry. In medical dosimetry, TLDs are used to measure the dose of radiation received by patients during radiation therapy. In environmental monitoring, TLDs are used to measure the levels of background radiation in the environment. In personal dosimetry, TLDs are used to monitor the radiation exposure of workers in industries where radiation is used or produced.

Advantages and disadvantages

TLDs have several advantages over other types of radiation detectors, including their small size, their ability to measure dose over a long period of time, and their ability to measure dose in a wide range of radiation fields. However, TLDs also have some disadvantages, including their need for a heating process to read the dose, their susceptibility to fading, and their relatively high cost compared to other types of detectors.

See also

• Dosimetry
• Radiation therapy
• Ionizing radiation
• Radiation protection

• Thermoluminescent dosimeter
  Thermoluminescent dosimeter
• Radiation safety badges
  Radiation safety badges