Which is the correct component used by thermoluminescent dosimeters to store dose information?

• A. Semiconductor crystals
• B. Phosphor crystals
• C. Gaseous detectors
• D. Photographic film

Answer: (B)

Thermoluminescent dosimeters store dose information in luminescent phosphor crystals. When irradiated, defects within the crystal trap charge carriers. Upon heating, these trapped charges are released and recombine, emitting light in proportion to the absorbed dose. Materials such as LiF doped with Mg, Ti (and similar phosphor crystals) are typical for TLDs because the emitted light during readout directly reflects the radiation exposure.

The other options describe different detection methods: semiconductor crystals are used in electronic dosimeters, gaseous detectors rely on ionization in gas to measure dose, and photographic film records exposure by darkening the emulsion, not by releasing stored trapped energy as light.