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[en] Sixteen radon measurement services participated in the 2008 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at the Paul Scherrer Institute (PSI) during August 28th to September 7th, 2008 on behalf of the Swiss Federal Office of Public Health (FOPH). Twelve of these laboratories were approved by the FOPH and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas dosemeters (etched-track, electronic and electret ionisation chambers) and instruments (ionization chambers) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 627 Bq m-3 leading to a radon gas exposure of 155 kBq h m-3. One measuring instrument participating for testing purposes stored values for part of the exposure interval (30.8. - 7.9.2008). The exposure during this partial interval was 117 kBq h m-3 at an average radon gas concentration of 624 Bq m-3. The exposure of 155 kBq h m-3 was the lowest used at the PSI intercomparisons down to the present day. Especially the LLT electret ionisation chambers used by some of the laboratories reached the lower end of their measurement range with this exposure. Unexpected deviations of instruments of the same model seem to show a dependence on the serial number and thus production date. (authors)
Source
Sep 2010; 50 p; ISSN 1019-0643; 
[en] Twenty radon measurement services or the respective analytical laboratories participated in the 2010 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at the Paul Scherrer Institute (PSI) from August 27th to August 31st, 2010 on behalf of the Swiss Federal Office of Public Health (FOPH). Twelve of these laboratories were approved by the FOPH and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas dosemeters (track-etch, electronic and electret) and instruments (ionisation chambers) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 595 Bq m-3 leading to a radon gas exposure of 57 kBq h m-3. The exposure of 57 kBq h m-3 was close to the lower value of the measuring range defined in the Radon Measurement Ordinance ('Radon-Messmittelverordnung'). (authors)
Source
Jan 2011; 49 p; ISSN 1019-0643;
[en] This paper proposes an approach to maintenance optimization of nuclear power plant components, which can help to increase both safety and availability. In order to evaluate the benefits of preventive maintenance on a quantitative basis, a software code has been developed for component performance and reliability simulation of safety related nuclear power plant equipment. A three state Markov model will be introduced, considering a degraded state in addition to an operational state and a failed state. (author)
Source
International Atomic Energy Agency, Vienna (Austria); 231 p; ISSN 1011-4289; ; Mar 2000; p. 39-58; Technical committee meeting on advances in safety related maintenance; Vienna (Austria); 15-19 Sep 1997; 24 figs, 2 tabs
; Mar 2000; p. 39-58; Technical committee meeting on advances in safety related maintenance; Vienna (Austria); 15-19 Sep 1997; 24 figs, 2 tabs
[en] The measurement flights of the exercise ARM10 were performed between 5th and 8th of July 2010 under the direction of G. Scharding of the National Emergency Operations Centre (NAZ) and coordination by the Expert Group for Aeroradiometrics (FAR). According to the alternating schedule of the annual ARM exercises, the environs of the nuclear power plants Beznau (KKB) and Leibstadt (KKL) as well as those of the Paul Scherrer Institute (PSI) research facility and of the Intermediate Storage Facility for Nuclear Waste (ZWILAG) were inspected. In cooperation with German authorities the measuring area was extended with a region north of the Rhine river. The values measured over the premises of KKB, KKL, ZWILAG and PSI matched with the results obtained in previous years. On request by the Federal Office of Public Health (FOPH) areas near Posieux, Guettingen, Cadenazzo and Affoltern/ZH were inspected. These locations are intended as reference areas for the radiological surveillance of the environment by FOPH. In preparation of an international intercomparison exercise scheduled for 2011 in the field of in-situ gamma-spectrometry, an area located in the Dischma Valley was measured with airborne gamma-spectrometry. Measuring flights along three profiles supplemented aeroradiometric data in Swiss regions which were not covered before by airborne gamma-spectrometry.(authors)
Source
Jun 2011; 89 p; ISSN 1019-0643;
[en] Detailed information is given on an experiment which was carried out to investigate the spin-dependent attenuation of electron beams transmitted through a vapour of chiral molecules. The experiment is considered to be the first verification of electron dichroism. A transmission asymmetry for longitudinally polarized electron beams of opposite helicity was observed for Yb(hfc)3, a camphor-like molecule containing an ytterbium atom, and also recently for bromocamphor. Asymmetries of about 1.5 x 10-4, which is clearly above the detection limit, were measured for both targets at electron energies between 0.5 and 10 eV. No asymmetry was found when enantiometric camphor vapour was used as the target, thus contradicting a result which has been previously published by another group. The asymmetry measurements are compared with electron transmission spectra, which show that the energies where resonant temporary-ion formation takes place and those of the extrema of the asymmetry agree to a great extent. (author)
Journal
Journal of Physics. B, Atomic, Molecular and Optical Physics; ISSN 0953-4075; ; CODEN JPAPEH; v. 29(15); p. 3497-3511
; CODEN JPAPEH; v. 29(15); p. 3497-3511
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