The Experts below are selected from a list of 2547 Experts worldwide ranked by ideXlab platform

Matthieu Hamel - One of the best experts on this subject based on the ideXlab platform.

  • sensitive and transportable gadolinium core plastic scintillator sphere for Neutron detection and counting
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2016
    Co-Authors: Jonathan Dumazert, Laurence Méchin, Romain Coulon, Franck Carrel, Gwénolé Corre, Stéphane Normand, Matthieu Hamel
    Abstract:

    Abstract Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to Neutron Counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal Neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast Neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore Neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast Neutrons and the probability of slow Neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the Neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient Neutron detector and orientate future investigation toward promising axes.

  • sensitive and transportable gadolinium core plastic scintillator sphere for Neutron detection and counting
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2016
    Co-Authors: Jonathan Dumazert, Laurence Méchin, Romain Coulon, Franck Carrel, Gwénolé Corre, Stéphane Normand, Matthieu Hamel
    Abstract:

    Abstract Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to Neutron Counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal Neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast Neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore Neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast Neutrons and the probability of slow Neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the Neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient Neutron detector and orientate future investigation toward promising axes.

Agramunt J. - One of the best experts on this subject based on the ideXlab platform.

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated He-3 Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Fraile Prieto, Luis Mario, Jordan D., Koster U., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He-3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He-3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10(-9) to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61 +/- 0.05), (1.96 +/- 0.15), and (4.6 +/- 0.4) x 10(-4) cm(-2) s(-1), respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Fraile L.m., Jordan D., Koster U., Marta M., Müller S.e.
    Abstract:

    International audienceAmbient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4  cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Jordan D., Koster U., Fraile L. M., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated $^3$He Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 meters of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each $^3$He counter-moderator assembly, the energy dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10$^{-9}$ MeV to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy integrated fluxes of $(0.61 \pm 0.05)$, $(1.96 \pm 0.15)$, and $(4.6 \pm 0.4) \times 10^{-4}$ cm$^{-2}$ s$^{-1}$, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.Comment: 10 figures, 4 tables; to be published in Phys. Rev.

  • First determination of β-delayed multiple Neutron emission beyond A = 100 through direct Neutron measurement : The P2n value of 136Sb
    'American Physical Society (APS)', 2018
    Co-Authors: Caballero-folch R., Agramunt J., Taín J. L., Algora A., Äystö Juha, Calviño F., Canete Laetitia, Cortès G., Domingo-pardo C.
    Abstract:

    Background: β-delayed multiple Neutron emission has been observed for some nuclei with A 100, being the 100Rb the heaviest β2n emitter measured to date. So far, only 25 P2n values have been determined for the ≈300 nuclei that may decay in this way. Accordingly, it is of interest to measure P2n values for the other possible multiple Neutron emitters throughout the chart of the nuclides. It is of particular interest to make such a measurement for nuclei with A > 100 to test the predictions of theoretical models and simulation tools for the decays of heavy nuclei in the region of very Neutron-rich nuclei. In addition, the decay properties of these nuclei are fundamental for the understanding of astrophysical nucleosynthesis processes, such as the r-process, and safety inputs for nuclear reactors. Purpose: To determine for the first time the two-Neutron branching ratio, the P2n value, for 136Sb through a direct Neutron measurement and to provide precise P1n values for 136Sb and 136Te. Method: A pure beam of each isotope of interest was provided by the JYFLTRAP Penning trap at the Ion Guide Isotope Separator On-Line (IGISOL) facility of the University of Jyväskylä, Finland. The purified ions were implanted into a moving tape at the end of the beam line. The detection setup consisted of a plastic scintillator placed right behind the implantation point after the tape to register the β decays and the BELEN detector, based on Neutron Counters embedded in a polyethylene matrix. The analysis was based on the study of the β- and Neutron-growth-and-decay curves and the β-one-Neutron and β-two-Neutron time correlations, which allowed us the determination of the Neutron-branching ratios. Results: The P2n value of 136Sb was found to be 0.14(3)% and the measured P1n values for 136Sb and 136Te were found to be 32.2(15)% and 1.47(6)%, respectively. Conclusions: The measured P2n value is a factor 44 smaller than predicted by the finite-range droplet model plus the quasiparticle random-phase approximation (FRDM+QRPA) model used for r-process calculations.peerReviewe

  • Ambient Neutron background in the shallow-underground laboratory Felsenkeller
    'World Scientific Pub Co Pte Lt', 2018
    Co-Authors: Hensel T., Agramunt J., Grieger M., Taín J.l., Bemmerer D., Müller S.e., Szücs T., Degering D., Fraile L.m.
    Abstract:

    International audienceOne important component of the ambient background in underground laboratories are Neutrons, which cover a wide energy range from thermal up to 100 MeV. After a few meters rock overburden, cosmic-ray Neutrons are a negligible contribution underground and the remaining flux is due to Neutron production by cosmic-ray muons and by (α,n) reactions from natural radioactivity in the rock. There are only a few measurements of the full spectral Neutron flux available in the literature, a fact which hampers comparisons between laboratories and negatively affects the planning of future experiments. In an effort to overcome this issue a setup consisting of six moderated and one unmoderated 3He Neutron Counters that has been used at a depth of 850 m in the Canfranc underground laboratory, Spain [1], was utilized to study the Neutron flux in the 48 m deep Dresden Felsenkeller underground laboratory, Germany. At Felsenkeller, an additional counter with a lead liner was used in order to address also the high-energy flux up to several hundreds of MeV

Marta M. - One of the best experts on this subject based on the ideXlab platform.

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated He-3 Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Fraile Prieto, Luis Mario, Jordan D., Koster U., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He-3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He-3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10(-9) to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61 +/- 0.05), (1.96 +/- 0.15), and (4.6 +/- 0.4) x 10(-4) cm(-2) s(-1), respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Fraile L.m., Jordan D., Koster U., Marta M., Müller S.e.
    Abstract:

    International audienceAmbient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4  cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Jordan D., Koster U., Fraile L. M., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated $^3$He Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 meters of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each $^3$He counter-moderator assembly, the energy dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10$^{-9}$ MeV to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy integrated fluxes of $(0.61 \pm 0.05)$, $(1.96 \pm 0.15)$, and $(4.6 \pm 0.4) \times 10^{-4}$ cm$^{-2}$ s$^{-1}$, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.Comment: 10 figures, 4 tables; to be published in Phys. Rev.

  • Neutron flux and spectrum in the dresden felsenkeller underground facility studied by moderated he 3 Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Hensel T., Bemmerer D., Degering D., Fraile L.m., Jordan D., Koster U., Agramunt Jorge, Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4 cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.Financial support by DFG (BE 4100/4-1), the Helmholtz Association (NAVI VH-VI-417 and ERC-RA-0016), the Spanish Ministerio de Economía y Competitividad (Grants No. FPA2014-52823-C2, No. FPA2017-83946-C2, No. RTI2018-098868-B-I00, and No. SEV-2014-0398/ program Severo Ochoa), and the COST Association (ChETEC CA16117) is gratefully acknowledge

Jonathan Dumazert - One of the best experts on this subject based on the ideXlab platform.

  • sensitive and transportable gadolinium core plastic scintillator sphere for Neutron detection and counting
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2016
    Co-Authors: Jonathan Dumazert, Laurence Méchin, Romain Coulon, Franck Carrel, Gwénolé Corre, Stéphane Normand, Matthieu Hamel
    Abstract:

    Abstract Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to Neutron Counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal Neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast Neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore Neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast Neutrons and the probability of slow Neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the Neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient Neutron detector and orientate future investigation toward promising axes.

  • sensitive and transportable gadolinium core plastic scintillator sphere for Neutron detection and counting
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2016
    Co-Authors: Jonathan Dumazert, Laurence Méchin, Romain Coulon, Franck Carrel, Gwénolé Corre, Stéphane Normand, Matthieu Hamel
    Abstract:

    Abstract Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to Neutron Counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal Neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast Neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore Neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast Neutrons and the probability of slow Neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the Neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient Neutron detector and orientate future investigation toward promising axes.

Grieger M. - One of the best experts on this subject based on the ideXlab platform.

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Fraile L.m., Jordan D., Koster U., Marta M., Müller S.e.
    Abstract:

    International audienceAmbient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4  cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated He-3 Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Fraile Prieto, Luis Mario, Jordan D., Koster U., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He-3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He-3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10(-9) to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61 +/- 0.05), (1.96 +/- 0.15), and (4.6 +/- 0.4) x 10(-4) cm(-2) s(-1), respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls

  • Neutron flux and spectrum in the Dresden Felsenkeller underground facility studied by moderated $^3$He Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Agramunt J., Hensel T., Bemmerer D., Degering D., Jordan D., Koster U., Fraile L. M., Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated $^3$He Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 meters of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each $^3$He counter-moderator assembly, the energy dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10$^{-9}$ MeV to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy integrated fluxes of $(0.61 \pm 0.05)$, $(1.96 \pm 0.15)$, and $(4.6 \pm 0.4) \times 10^{-4}$ cm$^{-2}$ s$^{-1}$, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.Comment: 10 figures, 4 tables; to be published in Phys. Rev.

  • Neutron flux and spectrum in the dresden felsenkeller underground facility studied by moderated he 3 Counters
    'American Physical Society (APS)', 2020
    Co-Authors: Grieger M., Hensel T., Bemmerer D., Degering D., Fraile L.m., Jordan D., Koster U., Agramunt Jorge, Marta M.
    Abstract:

    Ambient Neutrons may cause significant background for underground experiments. Therefore, it is necessary to investigate their flux and energy spectrum in order to devise a proper shielding. Here, two sets of altogether ten moderated He3 Neutron Counters are used for a detailed study of the ambient Neutron background in tunnel IV of the Felsenkeller facility, underground below 45 m of rock in Dresden/Germany. One of the moderators is lined with lead and thus sensitive to Neutrons of energies higher than 10 MeV. For each He3 counter moderator assembly, the energy-dependent Neutron sensitivity was calculated with the FLUKA code. The count rates of the ten detectors were then fitted with the MAXED and GRAVEL packages. As a result, both the Neutron energy spectrum from 10-9 to 300 MeV and the flux integrated over the same energy range were determined experimentally. The data show that at a given depth, both the flux and the spectrum vary significantly depending on local conditions. Energy-integrated fluxes of (0.61±0.05), (1.96±0.15), and (4.6±0.4)×10-4 cm-2 s-1, respectively, are measured for three sites within Felsenkeller tunnel IV which have similar muon flux but different shielding wall configurations. The integrated Neutron flux data and the obtained spectra for the three sites are matched reasonably well by FLUKA Monte Carlo calculations that are based on the known muon flux and composition of the measurement room walls.Financial support by DFG (BE 4100/4-1), the Helmholtz Association (NAVI VH-VI-417 and ERC-RA-0016), the Spanish Ministerio de Economía y Competitividad (Grants No. FPA2014-52823-C2, No. FPA2017-83946-C2, No. RTI2018-098868-B-I00, and No. SEV-2014-0398/ program Severo Ochoa), and the COST Association (ChETEC CA16117) is gratefully acknowledge

  • Ambient Neutron background in the shallow-underground laboratory Felsenkeller
    'World Scientific Pub Co Pte Lt', 2018
    Co-Authors: Hensel T., Agramunt J., Grieger M., Taín J.l., Bemmerer D., Müller S.e., Szücs T., Degering D., Fraile L.m.
    Abstract:

    International audienceOne important component of the ambient background in underground laboratories are Neutrons, which cover a wide energy range from thermal up to 100 MeV. After a few meters rock overburden, cosmic-ray Neutrons are a negligible contribution underground and the remaining flux is due to Neutron production by cosmic-ray muons and by (α,n) reactions from natural radioactivity in the rock. There are only a few measurements of the full spectral Neutron flux available in the literature, a fact which hampers comparisons between laboratories and negatively affects the planning of future experiments. In an effort to overcome this issue a setup consisting of six moderated and one unmoderated 3He Neutron Counters that has been used at a depth of 850 m in the Canfranc underground laboratory, Spain [1], was utilized to study the Neutron flux in the 48 m deep Dresden Felsenkeller underground laboratory, Germany. At Felsenkeller, an additional counter with a lead liner was used in order to address also the high-energy flux up to several hundreds of MeV