Beschreibung
Measurements of weakly penetrating radiation in personal dosimetry present problems in the design of suitable detectors and in the interpretation of their readings. For the measurement of the individual beta radiation dose, personal dosemeter for the fingers/tips are required. In general, the dosemeters currently used for personal monitoring of beta and low energy photon doses suffer from an energy threshold problem because the detector and/or the filter are too thick. TLDs of a standard thickness can seriously underestimate personal skin doses, especially in external fields of weakly penetrating radiation fields. LiF:Mg,Cu,P is a promising TL material which allows the production of thin detectors with sufficient sensitivity. Dosimetric properties of two different types of extremity dosemeters, designed to measure the personal dose equivalent Hp(0.07), have been compared: LiF:Mg,Ti (TLD100) and LiF:Mg,Cu, P (TLD700H). The first one consists of 100 mg.cm-2 LiF:Mg,Ti (TLD 100) chip and a 35mg. cm-2 cap, the other consists of a 7mg. cm-2 layer of LiF:Mg,Cu,P (TLD-700H) powder and a 5mg. cm-2 cap. The evaluation was done in two steps: Performance tests (ISO-12794) and measurements in real workplaces. In the first step type test results for beta calibration were compared. In addition calibration for low energy photon radiation according to ISO 4037-3 was carried out. In the second step, simultaneous measurements with both types of dosemeters were performed at workplaces, where radiopharmaceuticals containing different radioisotopes are prepared and applied. Practices in these fields are characterized by handling of high activities at very small distances between source and skin. The results from the comparison of the two dosimeter types are presented and analyzed with respect to different radiation fields. Experiments showed a satisfactory sensitivity for the thinner dosemeter (TLD 700H) for detecting beta radiation at protection levels and a good energy response.| Zeitraum | 11 Apr. 2005 → 15 Apr. 2005 |
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| Ereignistitel | IM2005 |
| Veranstaltungstyp | Sonstiges |
| Bekanntheitsgrad | International |
Research Field
- Biosensor Technologies