0000000000297792
AUTHOR
C. Eleftheriadis
Conceptual design of the International Axion Observatory (IAXO)
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few $\times 10^{-12}$ GeV$^{-1}$ and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling $g_{…
Deep sea tests of a prototype of the KM3NeT digital optical module
SIRE(opens in a new window)|View at Publisher| Export | Download | Add to List | More... European Physical Journal C Volume 74, Issue 9, 1 September 2014, 8p Deep sea tests of a prototype of the KM3NeT digital optical module: KM3NeT Collaboration (Article) Adrián-Martínez, S.a, Ageron, M.b, Aharonian, F.c, Aiello, S.d, Albert, A.e, Ameli, F.f, Anassontzis, E.G.g, Anghinolfi, M.h, Anton, G.i, Anvar, S.j, Ardid, M.a, de Asmundis, R.k, Balasi, K.l, Band, H.m, Barbarino, G.kn, Barbarito, E.o, Barbato, F.kn, Baret, B.p, Baron, S.p, Belias, A.lq, Berbee, E.m, van den Berg, A.M.r, Berkien, A.m, Bertin, V.b, Beurthey, S.b, van Beveren, V.m, Beverini, N.st, Biagi, S.uv, Bianucci, S.t, Billault, M.b,…
GEANT4 simulation of the neutron background of the C6D6 set-up for capture studies at n_TOF
The neutron sensitivity of the C6D6 detector setup used at n_TOF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has beeni mplemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with anatC sample, showing an excellent agreement above 1 keV. At lower energies, an additional compo…
Neutron measurements for advanced nuclear systems: The n_TOF project at CERN
A few years ago, the neutron time-of-flight facility n_TOF was built at CERN to address some of the urgent needs of high-accuracy nuclear data for Accelerator Driven Systems and other advanced nuclear energy systems, as well as for nuclear astrophysics and fundamental nuclear physics. Thanks to the characteristics of the neutron beam, and to state-of-the-art detection and acquisition systems, high quality neutron cross-section data have been obtained for a variety of isotopes, many of which radioactive. Following an important upgrade of the spallation target and of the experimental area, a new measurement campaign has started last year. After a brief review of the most important results obt…
Neutron cross section measurements at n_TOF for ADS related estudies
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main res…
Neutron capture cross section measurement ofU238at the CERN n_TOF facility in the energy region from 1 eV to 700 keV
The aim of this work is to provide a precise and accurate measurement of the U238(n,γ) reaction cross section in the energy region from 1 eV to 700 keV. This reaction is of fundamental importance for the design calculations of nuclear reactors, governing the behavior of the reactor core. In particular, fast reactors, which are experiencing a growing interest for their ability to burn radioactive waste, operate in the high energy region of the neutron spectrum. In this energy region most recent evaluations disagree due to inconsistencies in the existing measurements of up to 15%. In addition, the assessment of nuclear data uncertainty performed for innovative reactor systems shows that the u…
IAXO - The International Axion Observatory
The International Axion Observatory (IAXO) is a next generation axion helioscope aiming at a sensitivity to the axion-photon coupling of a few 10^{-12} GeV^{-1}, i.e. 1-1.5 orders of magnitude beyond sensitivities achieved by the currently most sensitive axion helioscope, the CERN Axion Solar Telescope (CAST). Crucial factors in improving the sensitivity for IAXO are the increase of the magnetic field volume together with the extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested at CAST. Electron-coupled axions invoked to explain the white dwarf cooling, relic axions, and a large variety of more generic axion-like particles (ALPs) along…
The Next Generation of Axion Helioscopes: The International Axion Observatory (IAXO)
Çetin, Serkant Ali (Dogus Author) -- Conference full title: 13th International Conference on Topics in Astroparticle and Underground Physics, TAUP 2013; Asilomar Conference Grounds Monterey Peninsula; United States; 8 September 2013 through 13 September 2013. The International Axion Observatory (IAXO) is a proposed 4th-generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 - 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion-photon coupling gaγ down to a few ×10-12 GeV-1 for a wide range of axion masses up to ∼ 0.25 eV. This is an improvement over the currently best …
Future axion searches with the International Axion Observatory (IAXO)
Çetin, Serkant Ali (Dogus Author) -- Conference full title: 6th Symposium on Large TPCs for Low Energy Rare Event Detection; Paris; France; 17 December 2012 through 19 December 2012. The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ ∼ few × 10-12 GeV-1, i.e. 1-1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO are an increased magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include …
Deep sea tests of a prototype of the KM3NeT digital optical module: KM3NeT Collaboration
The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deep waters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same $^{40…
Experimental neutron capture data of 58Ni from the CERN n_TOF facility
The $^{58}$Ni $(n,\gamma)$ cross section has been measured at the neutron time of flight facility n_TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT$=$5-100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2$\pm$0.6$_\mathrm{stat}\pm$1.8$_\mathrm{sys}$ mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When in…
Nuclear Data for the Thorium Fuel Cycle and the Transmutation of Nuclear Waste
Neutron-induced reaction cross sections play an important role in a wide variety of research fields, ranging from stellar nucleosynthesis, the investigation of nuclear level density studies, to applications of nuclear technology, including the transmutation of nuclear waste, accelerator-driven systems, and nuclear fuel cycle investigations. Simulations of nuclear technology applications largely rely on evaluated nuclear data libraries. These libraries are based both on experimental data and theoretical models. An outline of experimental nuclear data activities at CERN’s neutron time-of-flight facility, n_TOF, will be presented.
Measurement of the n-TOF beam profile with a micromegas detector
A Micromegas detector was used in the neutron Time-Of-Flight (n_TOF) facility at CERN to evaluate the spatial distribution of the neutron beam as a function of its kinetic energy. This was achieved over a large range of neutron energies by using two complementary processes: at low energy by capture of a neutron via the 6Li(n,[alpha])t reaction, and at high energy by elastic scattering of neutrons on gas nuclei (argon+isobutane or helium+isobutane). Data are compared to Monte Carlo simulations and an analytic function fitting the beam profile has been calculated with a sufficient precision to use in neutron capture experiments at the n_TOF facility. http://www.sciencedirect.com/science/artic…
The 236U neutron capture cross-section measured at the n TOF CERN facility
International audience; The $^{236}$U isotope plays an important role in nuclear systems, both for future and currently operating ones. The actual knowledge of the capture reaction of this isotope is satisfactory in the thermal region, but it is considered insufficient for Fast Reactor and ADS applications. For this reason the $^{236} \text{U}(n, \gamma)$ reaction cross-section has been measured for the first time in the whole energy region from thermal energy up to 1 MeV at the n_TOF facility with two different detection systems: an array of C$_6$D$_6$ detectors, employing the total energy deposited method, and a 4$\pi$ total absorption calorimeter (TAC), made of 40 BaF$_2$ crystals. The t…
High precision measurement of the radiative capture cross section of 238U at the n_TOF CERN facility
The importance of improving the accuracy on the capture cross-section of 238U has been addressed by the Nuclear Energy Agency, since its uncertainty significantly affects the uncertainties of key design parameters for both fast and thermal nuclear reactors. Within the 7th framework programme ANDES of the European Commission three different measurements have been carried out with the aim of providing the 238U(n,γ) cross-section with an accuracy which varies from 1 to 5%, depending on the energy range. Hereby the final results of the measurement performed at the n-TOF CERN facility in a wide energy range from 1 eV to 700 keV will be presented. © The Authors, published by EDP Sciences, 2017.
Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre
Full list of authors: Acharyya, A.; Adam, R.; Adams, C.; Agudo, I.; Aguirre-Santaella, A.; Alfaro, R.; Alfaro, J.; Alispach, C.; Aloisio, R.; Alves Batista, R.; Amati, L.; Ambrosi, G.; Angüner, E. O.; Antonelli, L. A.; Aramo, C.; Araudo, A.; Armstrong, T.; Arqueros, F.; Asano, K.; Ascasíbar, Y. Ashley, M.; Balazs, C.; Ballester, O.; Baquero Larriva, A.; Barbosa Martins, V.; Barkov, M.; Barres de Almeida, U.; Barrio, J. A.; Bastieri, D.; Becerra, J.; Beck, G.; Becker Tjus, J.; Benbow, W.; Benito, M.; Berge, D.; Bernardini, E.; Bernlöhr, K.; Berti, A.; Bertucci, B.; Beshley, V.; Biasuzzi, B.; Biland, A.; Bissaldi, E.; Biteau, J.; Blanch, O.; Blazek, J.; Bocchino, F.; Boisson, C.; Bonneau Arbe…
Fission fragment angular distribution of 232Th(n,f) at the CERN n TOF facility
The angular distribution of fragments emitted in neutron-induced fission of 232Th was measured in the white spectrum neutron beam at the n_TOF facility at CERN. A reaction chamber based on Parallel Plate Avalanche Counters (PPAC) was used, where the detectors and the targets have been tilted 45 degrees with respect to the neutron beam direction in order to cover the full angular range of the fission fragments. A GEANT4 simulation has been developed to study the setup efficiency. The data analysis and the preliminary results obtained for the 232Th(n,f) between fission threshold and 100 MeV are presented here.
Measurement of the 241Am neutron capture cross section at the n-TOF facility at CERN
New neutron cross section measurements of minor actinides have been performed recently in order to reduce the uncertainties in the evaluated data, which is important for the design of advanced nuclear reactors and, in particular, for determining their performance in the transmutation of nuclear waste. We have measured the 241 Am(n,γ) cross section at the n TOF facility between 0.2 eV and 10 keV with a BaF2 Total Absorption Calorimeter, and the analysis of the measurement has been recently concluded. Our results are in reasonable agreement below 20 eV with the ones published by C. Lampoudis et al. in 2013, who reported a 22% larger capture cross section up to 110 eV compared to experimental …