| Zugriffsnummer | 15767 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | The PTB underground calibration facility for very low dose rates |
| Autor(in); Institution |
Neumaier, Stefan; 6.32, Dosimetrie in der Umwelt, PTB-Braunschweig
Funck, Eberhard; 6.32, Dosimetrie in der Umwelt, PTB-Braunschweig
|
| Quelle/Jahr | Newsletter - EURADOS/EULEP:(2002), 11, 14 - 15 |
| ISSN | 1627-3680 ; 1627-3699 (ONLINE) |
| Verlag | Fontenay-aux-Roses: Institut de Protection et de Sûreté Nucléaire |
| Zusammenfassung | In 1991, the Physikalisch-Technische Bundesanstalt (PTB), the national metrological institute for physical sciences and technology in Germany, established an underground laboratory for dosimetry and spectrometry (UDO) in the Asse salt mine, near Braunschweig. UDO is located at the deepest floor of this mine, 925 m below ground. Due to this depth, the cosmic-ray muon intensity in this facility is reduced by more than five orders of magnitude compared to ground level. In addition, the low specific activity of the pure rock salt and a moderate activity concentration of radon in air (10 to 20 BQ/m3) result in an extremely low ambient dose equivalent rate of less than 1 nSv/h. The UDO laboratory is, therefore, well suited for dosimetry at very low dose rates, as well as for other applications which require low radiation levels or a very low muon intensity, such as low-background γ-ray spectrometry. The very low radiation level at UDO also allows the direct determination of the inherent background of detector systems by "long term" (several hours to days) measurements of the accumulated doses. In a few cases TLDs and other passive detectors were exposed at UDO for periods of up to one year. Finally, the underground facility UDO provides the only photon calibration facility, worldwide, for dose and dose rate meters at very low dose rates, traceable to national primary standards. |
