Technical Report No. 11-89

Calibration of Mg2SiO4 (Tb) thermoluminescent dosimeters for use in determining diagnostic X-ray doses to Adult Health Study participants

Kato K, Antoku S, Sawada S, Russell WJ
Editor’s note: A publication based on this report was published in Med Phys 18(5):928-33, 1991.
Summary
Characteristics of Mg2SiO4 (Tb) thermoluminescent dosimeters (TLD) were ascertained preparatory to measuring dose from diagnostic X-ray examinations received by Adult Health Study participants. These detectors are small, relatively sensitive to low-dose X rays, and are appropriate for precise dosimetry. Extensive calibration is necessary for precisely determining doses according to their thermoluminescent intensities. Their sensitivities were investigated by dose according to X-ray tube voltage and by exposure direction to obtain directional dependence. Dosimeter sensitivity lessened due to the fading effect and diminution of the planchet. However, these adverse effects can be avoided by storing the dosimeters at least 1.5 hours and by using fresh silver-plated planchets. Thus, the TLDs, for which sensitivities were determined in this study, will be useful in subsequent diagnostic X-ray dosimetry.

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