熱發光劑量計(thermoluminescent dosimeter, TLD)爲一普遍使用之人員輻射劑量偵測之工具。在TLD的計讀數值測定上，由於TLD在照射後需一定的時問以達到其能階陷阱捕獲電子之穩定；而輻射曝射完後TLD會受到背景輻射的影響而逐漸累積讀值，背景輻射亦有一部份比例可能在TLD中產生熱效應而使得先前累積之讀值減少，後者即所謂的消光，因此TLD照射後至開始測讀之時間會影響TLD最後讀數，進而影響劑量評估結果。本文以氟化鋰熱發光劑量計TLD-100及TLD-100H在照射後不同時間計讀進行測試與結果分析，藉此了解TLD之消光特性，以減少利用氟化鋰TLD進行劑量評估應用時之量測誤差與不確定度，提高TLD計讀結果的可信度。

Thermoluminescent dosimeter, TLD, is one of the most popular dosimeters used for radiation dose monitor. The time period between irradiation and read affects the final reading of the irradiated TLD, due to the time needed for stabilization of the captured electrons in the energy traps of the TLD and the effects of background radiation. Background radiation could increase the TLD reading by its ionization and excitation effects, and could decrease the reading by its heat effect; the last is so called as fading. This research measured the TLD readings with different time periods between irradiation and read to analyze the characteristic of fading of the TLD-100. Results of this paper could improve the understanding of the fading and could diminish the uncertainty in LiF TLD applications. Enhancement of the confidence of the dose assessment using TLD techniques can also be achieved.