| Autor: |
Baumgartner, Andreas, Steurer, Andreas, Tiefenböck, Wilhelm, Gabris, Frantisek, Maringer, Franz Josef, Kapsch, Ralf-Peter, Stucki, Gerhard |
| Předmět: |
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| Zdroj: |
Radiation Protection Dosimetry; Apr2011, Vol. 145 Issue 1, p3-12, 10p, 1 Diagram, 3 Charts, 3 Graphs |
| Abstrakt: |
The graphite calorimeter of the Federal Office of Metrology and Surveying (BEV-Bundesamt für Eich- und Vermessungswesen) was established in the 1980s as the primary standard for the absorbed dose to water for 60Co gamma ray beams. To maintain the primary standard at an international level the graphite calorimeter and its corresponding components had to undergo a refurbishment and modernisation process. The correction factors of the graphite calorimeter were re-evaluated with Monte Carlo and experimental methods to obtain improved values. These are the correction for the effect of the gaps (1.0061), the scaling correction (0.9998), the correction for the difference in air attenuation (0.9971) and the corrections for the effective measurement depths in the graphite phantom for the graphite calorimeter (0.9886) and the CC01-105 ionisation chamber (0.9913). Consequently, it was necessary to change the reference value for the absorbed dose rate to water of the 60Co teletherapy unit used for the calibration of secondary standard dosemeters. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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