Search results for "Ground"
showing 10 items of 2432 documents
Gamma Ray Spectra from Thermal Neutron Capture on Gadolinium-155 and Natural Gadolinium
2019
Natural gadolinium is widely used for its excellent thermal neutron capture cross section, because of its two major isotopes: $^{\rm 155}$Gd and $^{\rm 157}$Gd. We measured the $\gamma$-ray spectra produced from the thermal neutron capture on targets comprising a natural gadolinium film and enriched $^{\rm 155}$Gd (in Gd$_{2}$O$_{3}$ powder) in the energy range from 0.11 MeV to 8.0 MeV, using the ANNRI germanium spectrometer at MLF, J-PARC. The freshly analysed data of the $^{\rm 155}$Gd(n, $\gamma$) reaction are used to improve our previously developed model (ANNRI-Gd model) for the $^{\rm 157}$Gd(n, $\gamma$) reaction, and its performance confirmed with the independent data from the $^{\r…
Material radioassay and selection for the XENON1T dark matter experiment
2017
The XENON1T dark matter experiment aims to detect weakly interacting massive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the…
Cosmic-ray muon flux at Canfranc Underground Laboratory
2019
Residual flux and angular distribution of high-energy cosmic muons have been measured in two underground locations at the Canfranc Underground Laboratory (LSC) using a dedicated Muon Monitor. The instrument consists of three layers of fast scintillation detector modules operating as 352 independent pixels. The monitor has flux-defining area of 1 m${}^{2}$, covers all azimuth angles, and zenith angles up to $80^\circ$. The measured integrated muon flux is $(5.26 \pm 0.21) \times 10^{-3}$ m${}^{-2}$s${}^{-1}$ in the Hall A of the LAB2400 and $(4.29 \pm 0.17) \times 10^{-3}$ m${}^{-2}$s${}^{-1}$ in LAB2500. The angular dependence is consistent with the known profile and rock density of the sur…
$^{222}$Rn emanation measurements for the XENON1T experiment
2021
The selection of low-radioactive construction materials is of utmost importance for the success of low-energy rare event search experiments. Besides radioactive contaminants in the bulk, the emanation of radioactive radon atoms from material surfaces attains increasing relevance in the effort to further reduce the background of such experiments. In this work, we present the $^{222}$Rn emanation measurements performed for the XENON1T dark matter experiment. Together with the bulk impurity screening campaign, the results enabled us to select the radio-purest construction materials, targeting a $^{222}$Rn activity concentration of 10 $\mu$Bq/kg in 3.2 t of xenon. The knowledge of the distribut…
Theia: an advanced optical neutrino detector
2020
The European physical journal. C, Particles and fields 80(5), 416 (2020). doi:10.1140/epjc/s10052-020-7977-8
The Monte Carlo simulation of the Borexino detector
2017
We describe the Monte Carlo (MC) simulation package of the Borexino detector and discuss the agreement of its output with data. The Borexino MC 'ab initio' simulates the energy loss of particles in all detector components and generates the resulting scintillation photons and their propagation within the liquid scintillator volume. The simulation accounts for absorption, reemission, and scattering of the optical photons and tracks them until they either are absorbed or reach the photocathode of one of the photomultiplier tubes. Photon detection is followed by a comprehensive simulation of the readout electronics response. The algorithm proceeds with a detailed simulation of the electronics c…
A 4 tonne demonstrator for large-scale dual-phase liquid argon time projection chambers
2018
A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and offers several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phase liquid argon TPC prototype, the largest of its kind, with an active volume of \three has been constructed and operated at CERN. In this paper we describe in detail the experimental setup and detector components as well as report on the operation experience. We also present the first results on the achieved charge amplification, prompt scintillat…
A detector for CLIC: main parameters and performance
2019
Together with the recent CLIC detector model CLICdet a new software suite was introduced for the simulation and reconstruction of events in this detector. This note gives a brief introduction to CLICdet and describes the CLIC experimental conditions at 380 GeV and 3 TeV, including beam-induced backgrounds. The simulation and reconstruction tools are introduced, and the physics performance obtained is described in terms of single particles, particles in jets, jet energy resolution and flavour tagging. The performance of the very forward electromagnetic calorimeters is also discussed.
Feasibility and physics potential of detecting $^8$B solar neutrinos at JUNO
2021
The Jiangmen Underground Neutrino Observatory (JUNO) features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector. Some of JUNO's features make it an excellent location for 8B solar neutrino measurements, such as its low-energy threshold, high energy resolution compared with water Cherenkov detectors, and much larger target mass compared with previous liquid scintillator detectors. In this paper, we present a comprehensive assessment of JUNO's potential for detecting 8B solar neutrinos via the neutrino-electron elastic scattering process. A reduced 2 MeV threshold for the recoil electron energy is found to be achievable, assuming that the intrinsic radioactive …
Study of ordered hadron chains with the ATLAS detector
2017
The analysis of the momentum difference between charged hadrons in high-energy proton-proton collisions is performed in order to study coherent particle production. The observed correlation pattern agrees with a model of a helical QCD string fragmenting into a chain of ground-state hadrons. A threshold momentum difference in the production of adjacent pairs of charged hadrons is observed, in agreement with model predictions. The presence of low-mass hadron chains also explains the emergence of charge-combination-dependent two-particle correlations commonly attributed to Bose-Einstein interference. The data sample consists of 190 μb-1 of minimum-bias events collected with proton-proton colli…