What type of crystal is used in a thermoluminescent dosimeter (TLD)?

A thermoluminescent dosimeter (TLD) typically uses lithium fluoride as its sensing material. The reason lithium fluoride is favored is due to its favorable properties for detecting ionizing radiation. When ionizing radiation interacts with lithium fluoride, it creates electron-hole pairs. When the TLD is subsequently heated, the trapped electrons are released, and this results in the emission of light. The amount of light emitted is proportional to the amount of radiation exposure, which allows for accurate dosimetry.

Additionally, lithium fluoride has a high atomic number and density, making it effective at measuring a wide range of radiation types. Its thermoluminescent properties offer a reliable and sensitive method for assessing exposure levels, which is essential for ensuring safety in environments where radiation is present.

Other materials such as aluminum oxide, calcium sulfate, and silicon dioxide may have uses in different contexts or applications in radiation monitoring, but they do not exhibit the same levels of sensitivity and effectiveness in thermoluminescent dosimetry as lithium fluoride does.