Measurement of the background in the NEMO 3 double beta decay experiment Argyriades, J.; Arnold, R.; Augier, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2009, Letnik:
606, Številka:
3
Journal Article
Recenzirano
Odprti dostop
In the double beta decay experiment NEMO 3 a precise knowledge of the background in the signal region is of outstanding importance. This article presents the methods used in NEMO 3 to evaluate the ...backgrounds resulting from most if not all possible origins. It also illustrates the power of the combined tracking-calorimetry technique used in the experiment.
Low background germanium planar detector for gamma-ray spectrometry Loaiza, P.; Chassaing, C.; Hubert, Ph ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
634, Številka:
1
Journal Article
Recenzirano
A new ultra-low background planar germanium spectrometer has been developed. The planar geometry improves the sensitivity and energy resolution below 600
keV. The integral background counting rate in ...the Laboratoire Souterrain de Modane (4800
m water equivalent) in the energy range from 20 to 1500
keV for the planar Ge (mass=800
g) is 140
count/day. After 40 days of statistics, the background counting rates for all expected single lines are below 0.5
count/day with the exception of
210Pb(46-keV line) which was measured to be (1.76±0.25)
count/day. Monte Carlo simulations have been performed to explain the origin of the remaining background and to calculate the detection efficiencies. Sensitivities around 1
mBq/kg are obtained within few days of statistics for
226Ra and
228Th. The main achievement is the high sensitivities for
210Pb (46-keV line) and
238U (
234Th: 63 and 93
keV lines). For an aluminium sample (mass=1
kg) the limits obtained in 15 days are
210
Pb
<
9
mBq
/
kg
and
238
U
<
3
mBq
/
kg
.
A reference material designed for the determination of natural radionuclides in solid samples (glass pellets) is described and the results of certification are presented. The material has been ...certified for 7 natural radionuclides (
40
K,
226
Ra,
228
Ra,
228
Th,
232
Th,
235
U and
238
U). An information value is given for
210
Pb. Radon (
222
Rn) emanation experiments showed results comparable within participating laboratories, however, the number of data and precision was too low to carry out a certification process. The reference material may be used for quality management of analytical laboratories engaged in the high-sensitive analysis of radionuclides in the construction materials of detectors placed in ultra low background underground laboratories.
This study explores whether absorptive capacity, one of the most important concepts in the literature on inter-partner learning and innovation in alliances, can be directly transposed to cross-sector ...alliances. The results of the analysis suggest that current models of absorptive capacity only imperfectly reflect the learning and innovation dynamics characteristic of cross-sector alliances, due to differences in alliance partners, their goals, and the type of innovations they pursue. This article introduces the concept of relational capacity for Social Innovation, a model better suited to the analysis of learning and innovation in the context of cross-sector alliances, especially those operating at the base of the economic pyramid.
The effects of the copper extractant LIX 984N 20% v/v in Shellsol 2046 on the abilities of
Acidithiobacillus ferrooxidans and
Sulfobacillus thermosulfidooxidans to catalyse copper extraction from a ...chalcopyrite concentrate and to oxidise ferrous ion to ferric ion were compared and the possible role of
Acidiphilium cryptum in ameliorating the effects of the SX reagent was examined. The SX reagent up to 250 mg/L was found to have little impact on the extraction of copper from a chalcopyrite concentrate using
At. ferrooxidans. In contrast, with
S. thermosulfidooxidans, copper extraction was reduced to about one third in the presence of 50 mg/L SX reagent and at 250 mg/L SX reagent, was barely more than for an abiotic test. The SX reagent strongly inhibited ferrous ion biooxidation by several bacterial species in contrast to
At. ferrooxidans. The presence of 50 mg/L SX reagent caused oxidation rates to drop to between 0 and 12% of those in controls in approximately 40-hour tests. The most toxic component of the SX reagent was found to be 4-nonylphenol.
A. cryptum tolerated 250 mg/L SX reagent but did not utilise it as an energy source. Bioleaching of chalcopyrite concentrate was not enhanced significantly when
A. cryptum was added to test inocula. It is proposed that
A. cryptum utilises fungal biomass as an energy source in managed heaps with solution recycle via solvent extraction plants. While it shares the environment with iron- and sulfur-oxidising acidophiles, it does not contribute directly to copper extraction from sulfide minerals.
Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. ...Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was 131I with maximum activity values of 2.4 mBq/m3 in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The 134,137Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m3 and 0.7 Bq/kg respectively, around one order of magnitude less than 131I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident.
Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. ...Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was (131)I with maximum activity values of 2.4 mBq/m(3) in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The (134,137)Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m(3) and 0.7 Bq/kg respectively, around one order of magnitude less than (131)I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident.
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