| 1. |
- Abgrall, N., et al.
(author)
-
The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)
- 2017
-
In: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. ; 1894
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Conference paper (peer-reviewed)abstract
- The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.
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| 2. |
- Pham, M. K., et al.
(author)
-
Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)
- 2006
-
In: Proceedings of the 15th International Conference on Radionuclide Metrology and its Applications (Applied Radiation and Isotopes). - Amsterdam : Elsevier BV. - 0969-8043 .- 1872-9800. ; 64:10-11, s. 1253-1259
-
Conference paper (peer-reviewed)abstract
- A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (Sr-90, Pb-210(Po-210), Ra-226, Pu-239, Pu-240 Pu-241). Less frequently reported radionuclides (Tc-99, I-129, Th-228, Th-230 and Np-217) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units.
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| 3. |
- Pham, M. K., et al.
(author)
-
Certified Reference Material IAEA-446 for radionuclides in Baltic Sea seaweed
- 2014
-
In: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 87, s. 468-474
-
Journal article (peer-reviewed)abstract
- A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The K-40, Cs-132, U-234 and Pu239+240 radionuclides were certified for this material, and information values for 12 other radionuclides (Sr-90, Tc-99, Pb-210 (Po-210), Ra-226, Ra-228, Th-228, Th-230, Th-232, U-235, U-238, Pu-239 and Pu-240) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation of analytical methods, and for training purposes. (C) 2013 Elsevier Ltd. All rights reserved.
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| 4. |
- Outola, I., et al.
(author)
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Characterization of the NIST Seaweed Standard Reference Material
- 2006
-
In: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043. ; 64:10-11, s. 1242-1247
-
Journal article (peer-reviewed)abstract
- The National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) for seaweed was developed through an interlaboratory comparison with 24 participants from 16 countries. After evaluating different techniques to calculate certified values for the radionuclides, the median method was found to be the most representative technique. The certified values were provided for 13 radionuclides and information values were given for 15 more radionuclides. Results for the natural decay series showed disequilibrium in both the uranium and thorium series. (c) 2006 Elsevier Ltd. All rights reserved.
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| 5. |
- Pham, M K, et al.
(author)
-
A certified reference material for radionuclides in the water sample from Irish Sea (IAEA-443)
- 2011
-
In: JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY. - : Springer Science Business Media. - 0236-5731 .- 1588-2780. ; 288:2, s. 603-611
-
Journal article (peer-reviewed)abstract
- A new certified reference material (CRM) for radionuclides in sea water from the Irish sea (IAEA-443) is described and the results of the certification process are presented. Ten radionuclides (H-3, K-40, Sr-90, Cs-137, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) have been certified, and information values on massic activities with 95% confidence intervals are given for four radionuclides (Th-230, Th-232, Pu-239 and Pu-240). Results for less frequently reported radionuclides (Tc-99, Th-228, Np-237 and Pu-241) are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in water samples, for the development and validation of analytical methods and for training purposes. The material is available in 5 L units from IAEA (http://nucleus.iaea.org/rpst/index.htm).
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| 6. |
- Abdelhameed, A. H., et al.
(author)
-
Cryogenic characterization of a LiAlO2 crystal and new results on spin-dependent dark matter interactions with ordinary matter: CRESST Collaboration
- 2020
-
In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 80:9
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Journal article (peer-reviewed)abstract
- In this work, a first cryogenic characterization of a scintillating LiAlO2 single crystal is presented. The results achieved show that this material holds great potential as a target for direct dark matter search experiments. Three different detector modules obtained from one crystal grown at the Leibniz-Institut fur Kristallzuchtung (IKZ) have been tested to study different properties at cryogenic temperatures. Firstly, two 2.8 g twin crystals were used to build different detector modules which were operated in an above-ground laboratory at the Max Planck Institute for Physics (MPP) in Munich, Germany. The first detector module was used to study the scintillation properties of LiAlO2 at cryogenic temperatures. The second achieved an energy threshold of (213.02 +/- 1.48) eV which allows setting a competitive limit on the spin-dependent dark matter particle-proton scattering cross section for dark matter particle masses between 350 MeV/c2 and 1.50 GeV/c2. Secondly, a detector module with a 373 g LiAlO2 crystal as the main absorber was tested in an underground facility at the Laboratori Nazionali del Gran Sasso (LNGS): from this measurement it was possible to determine the radiopurity of the crystal and study the feasibility of using this material as a neutron flux monitor for low-background experiments.
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| 7. |
- Abdelhameed, A. H., et al.
(author)
-
Geant4-based electromagnetic background model for the CRESST dark matter experiment
- 2019
-
In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 79:10
-
Journal article (peer-reviewed)abstract
- The CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) dark matter search experiment aims for the detection of dark matter particles via elastic scattering off nuclei in CaWO4 crystals. To understand the CRESST electromagnetic background due to the bulk contamination in the employed materials, a model based on Monte Carlo simulations was developed using the Geant4 simulation toolkit. The results of the simulation are applied to the TUM40 detector module of CRESST-II phase 2. We are able to explain up to (68 +/- 16)% of the electromagnetic background in the energy range between 1 and 40 keV.
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| 8. |
- Bertoldo, E., et al.
(author)
-
Lithium-Containing Crystals for Light Dark Matter Search Experiments
- 2020
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In: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 199:1-2, s. 510-518
-
Journal article (peer-reviewed)abstract
- In the current direct dark matter search landscape, the leading experiments in the sub-GeV mass region mostly rely on cryogenic techniques which employ crystalline targets. One attractive type of crystals for these experiments is those containing lithium, due to the fact that 7Li is an ideal candidate to study spin-dependent dark matter interactions in the low mass region. Furthermore, 6Li can absorb neutrons, a challenging background for dark matter experiments, through a distinctive signature which allows the monitoring of the neutron flux directly on site. In this work, we show the results obtained with three different detectors based on LiAlO 2, a target crystal never used before in cryogenic experiments.
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| 9. |
- Kluck, H., et al.
(author)
-
Latest results of CRESST-III's search for sub-GeV/c(2) dark matter
- 2020
-
In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 1468:1
-
Conference paper (peer-reviewed)abstract
- The CRESST-III experiment searches for direct interactions of dark matter with ordinary matter. The main event signature would be a nuclear recoil inside one of the scintillating CaWO4 crystals. Operating the crystals as cryogenic calorimeters provides a phonon signal as measure of the deposited energy. The simultaneous readout of both signals is used to actively discriminate backgrounds. CRESST-III focuses on the sub-GeV/c(2) mass region where the sensitivity is driven by the threshold. In the first data taking campaign of CRESST-III from 2016-2018 an unprecedented low threshold of 30.1 eV for nuclear recoils was obtained. In this contribution, we will report the status of the experiment and the latest results. [GRAPHICS]
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| 10. |
- Mancuso, M., et al.
(author)
-
Searches for Light Dark Matter with the CRESST-III Experiment
- 2020
-
In: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 199:1-2, s. 547-555
-
Journal article (peer-reviewed)abstract
- Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) is a long-standing direct dark matter detection experiment with cryogenic detectors located at the underground facility Laboratori Nazionali del Gran Sasso in Italy. CRESST-III, the third generation of CRESST, was specifically designed to have a world-leading sensitivity for low-mass dark matter (DM) (less than 2 GeV/c 2) to probe the spin-independent DM-nucleus cross section. At present, a large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below few GeV/c 2 although many motivated theoretical models having been proposed. The CRESST-III experiment employs scintillating CaWO 4 crystals of ∼ 25 g as target material for dark matter interactions operated as cryogenic scintillating calorimeters at ∼ 10 mK. CRESST-III first data taking was successfully completed in 2018, achieving an unprecedented energy threshold for nuclear recoils. This result extended the present sensitivity to DM particles as light as ∼ 160 MeV/c 2. In this paper, an overview of the CRESST-III detectors and results will be presented.
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| 11. |
- Pham, M. K., et al.
(author)
-
A new reference material for radionuclides in the mussel sample from the Mediterranean Sea (IAEA-437)
- 2010
-
In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 283:3, s. 851-859
-
Journal article (peer-reviewed)abstract
- A new Reference Material (RM) for radionuclides in mussel (Mytilus galloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides (K-40, U-234, U-238, and Pu239+240) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides (Cs-137, Pb-210(Po-210), Ra-226, Ra-228, Th-228, Th-230, Th-232, U-235, and Am-241). Results for less frequently reported radionuclides (Sr-90, I-129, Pu-238, Pu-239, and Pu-240) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel samples, for the development and validation of analytical methods and for training purposes. The material is available in 200 g units.
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| 12. |
- Povinec, Pavel, et al.
(author)
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Reference material for radionuclides in sediment. IAEA-384 (Fangataufa lagoon sediment).
- 2007
-
In: Journal of Radioanalytical and Nuclear Chemistry. - Dordrecht : Springer. - 0236-5731 .- 1588-2780. ; 273:2, s. 383-393
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Journal article (peer-reviewed)abstract
- A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units.
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| 13. |
- Pettersson, Håkan, 1956-, et al.
(author)
-
Summary of IAEA-MEL's investigation of Kara Sea radioactivity and radiological assessment
- 1997
-
In: Marine Pollution Bulletin. - 0025-326X .- 1879-3363. ; 35:7-12, s. 235-241
-
Journal article (peer-reviewed)abstract
- IAEA-MEL participated in five expeditions to the Kara Sea with the aim of assessing the radiological consequences of dumped radioactive wastes in the Novaya Zemlya Bays and Trough. The programme included sampling, in-situ underwater investigations, laboratory analyses of water, sediment and biota samples, the development of a marine radioactivity database, modelling and radiological assessment, the organization of intercomparison exercises and the evaluation of distribution coefficients. Radiometric investigations have shown that no radiologically significant environmental contamination has occurred. Leakages which have led to locally increased levels of radionuclides in sediment have only been observed in Stepovoy and Abrosimov Bays. Computer modelling results suggest that only radiological effects on local and regional scales may be of importance. The global radiological impact of the disposals in the Arctic Seas will be negligible.
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| 14. |
- Pham, M. K., et al.
(author)
-
A new Certified Reference Material for radionuclides in Irish sea sediment (IAEA-385)
- 2008
-
In: APPLIED RADIATION AND ISOTOPES. - : Elsevier BV. - 1872-9800 .- 0969-8043. ; 66:11, s. 1711-1717
-
Conference paper (peer-reviewed)abstract
- A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides (K-40, Cs-137, Ra-226, Ra-228, Th-230, Th-232, U-234, U-238, Pu-238, Pu239+240 and Am-241) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides (Sr-90, Pb-210(Po-210), U-235, Pu-239, Pu-240 and Pu-241). Results for less frequently reported radionuclides (Co-60, Tc-99, Cs-134, Eu-155, Ra-224 and Np-239) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes. (C) 2008 IAEA. Published by Elsevier Ltd. All rights reserved.
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| 15. |
- Pham, M. K., et al.
(author)
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Certified reference material IAEA-418 : 129I in Mediterranean Sea water
- 2010
-
In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 286:1, s. 121-127
-
Journal article (peer-reviewed)abstract
- A certified reference material designed for the determination of I-129 in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median of I-129 concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given as the certified value, is 2.28 x 10(8) atom L-1 (95% confidence interval is (2.16-2.73) 10(8) atom L-1), or 3.19 x 10(-7) Bq L-1 (95% confidence interval is (3.02-3.82) x 10(-7) Bq L-1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories. It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).
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| 16. |
- Luis Mas, Jose, et al.
(author)
-
Analysis of a major Aeolian dust input event and its impact on element fluxes and inventories at the DYFAMED site (Northwestern Mediterranean)
- 2020
-
In: Marine Chemistry. - : ELSEVIER. - 0304-4203 .- 1872-7581. ; 223
-
Journal article (peer-reviewed)abstract
- Continental dust can be suspended and transported by the wind, reaching seawater masses far away from its source. The deposition of the aerosols on the ocean surface can alter the abundance of chemical species in the water column and contribute to element inventories in seafloor sediments. A major Saharan dust intrusion into the Western Mediterranean Sea was recorded at the DYFAMED site (Ligurian Sea) in 20th February 2004. We determined the influence of this dust event on the concentration of 30 minor and trace level elements (TE) in sinking particles collected by sediment traps deployed at 200 m and 1000 m depth, and how a dust flux event like this contributed to the exchange of TE, including Fe, with the water column during major dust events. With coupled sediment traps and aerosol samples, we assessed the short-term implications of dust events in the water column. The event produced a flux of fast (>111 m d(-1)) and slow ( < 20 m d(-1)) sinking dust particles, detected during 3 weeks at 200 m and 4 weeks at 1000 m depth. Additionally, the obtained results of element concentrations and particles flux show that a single dust deposition event can produce a sinking flux equivalent to annual deposition rates of elements relevant to biogeochemical cycles and/or pollution studies: (>60% for Cr and Cu, >70% for Al, > 80% for Ni and Zn, > 90% for V and Mn, > 100% for Fe and Pb). The corresponding Enrichment Factors (EF) for the minor and TE analyzed in the sediment traps during the dust event were calculated. EF was used to determine how minor and trace element concentrations in sinking particles vary. The values ranged between 0.35 and 421 in both 200 m and 1000 m sediment traps. For most of the analyzed elements, the obtained EF values were higher than 1. On the contrary, V, Y, Zr, Nb, and Ce showed EF similar to 1 while Cr, Ni, Cu, Zn, Sn, and Pb showed EF < 1. Despite the variability in the EF values, vertical fluxes integrated during the dust deposition event increased from 200 m to 1000 m, except for I, which decreased. This contrasts strongly with the element fluxes integrated for the complete sampling period, which decrease or increase from 200 m to 1000 m, depending on the element. This suggests that sinking dust particles were acting generally as sinks of the TE. We conclude that, apart from I, a substantial portion of the elements from atmospheric dust input from a single deposition event can reach the mesopelagic layer of the Western Mediterranean basin without increasing the budget of those elements in the water column.
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| 17. |
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