Underground Hall Research Articles

Rock neutron backgrounds from FNAL neutrino beamlines in the νBDX−DRIFT detector

The $\ensuremath{\nu}\mathrm{BDX}\text{\ensuremath{-}}\mathrm{DRIFT}$ Collaboration seeks to detect low-energy nuclear recoils from $\mathrm{CE}\ensuremath{\nu}\mathrm{NS}$ or BSM interactions at FNAL. Backgrounds due to rock neutrons are an important concern. We present a genie and geant4 based model to estimate backgrounds from rock neutrons produced in neutrino-nucleus interactions within the rock walls surrounding the underground halls. This model was bench-marked against the 2009 COUPP experiment performed in the MINOS hall in the NuMI neutrino beam, and agreement is found between experimental results and the modeled result to within 30%. Working from this validated model, a similar two-stage simulation was performed to estimate recoil backgrounds in the $\ensuremath{\nu}\mathrm{BDX}\text{\ensuremath{-}}\mathrm{DRIFT}$ detector across several beamlines. In the first stage utilizing geant4, neutrons were tallied exiting the walls of a rectangular underground hall utilizing four different neutrino beam configurations. These results are presented for use by other underground experiments requiring estimations of their rock neutron backgrounds. For $\ensuremath{\nu}\mathrm{BDX}\text{\ensuremath{-}}\mathrm{DRIFT}$, the second stage propagated neutrons from the walls and recorded energy deposited within a scintillator veto surrounding the detector and nuclear recoils within the detector's fiducial volume. The directional signal from the $\ensuremath{\nu}\mathrm{BDX}\text{\ensuremath{-}}\mathrm{DRIFT}$ detector allows additional background subtraction. A sample calculation of a $10\text{ }\text{ }{\mathrm{m}}^{3}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{yr}$ exposure to the NuMI low-energy beam configuration shows a $\mathrm{CE}\ensuremath{\nu}\mathrm{NS}$ signal-to-noise ratio of $\ensuremath{\sim}2.5$.

Conceptual Design of DUNE Near Detector Superconducting Magnet System

The Deep Underground Neutrino Experiment (DUNE) formed a near detector design group (NDDG) which was tasked with delivering a CDR by the end of 2019. The DUNE Near Detectors will be housed in an underground hall on the Fermilab site. The two main detector systems are a liquid argon detector and a high-pressure gas time projection chamber (HPgTPC). The HPgTPC requires a magnet that generates a 0.5 T solenoidal magnetic field in a large volume of 6 m diameter, and 5 m length. In this paper, we present a superconducting magnet system design. We investigated: an open air core magnet with three coils, and a five-coil s system having two active fringe field shielding coils. Coils positions were optimized to obtain the specified field homogeneity in the magnet good field region, while minimizing the Lorentz forces and the superconductor volume. We discuss the magnetic, mechanical, and thermal conceptual designs.

Deformation Features of Rock Mass Enclosing Underground Machine Hall of Rogun HPP at Final Construction Stage

This paper presents an analysis of observations of the displacement of the rock mass at the site of the underground machine hall of the Rogun hydropower plant during its completion. The main features of the displacement of the rock mass are considered and the advantages of using multipoint extensometers to observe the state of the rock mass are noted.

The LA3M Archaeological Mission in Yereruyk. Main results from the 2009-2016 campaigns

The LA3M Laboratory of Aix Marseille University (France), in cooperation with the Institute of Archaeology and Ethnography of the Armenian Academy, represented on the ground by the Regional Museum of Shirak, has carried out, from 2009 to 2016, an archaeological survey of the early Christian and medieval site of Yereruyk. The project was aimed at a multidisciplinary approach of the complex, combining armenology, history of art and architecture, building archaeology, classic archaeology, archaeological anthropology, and geo-archaeology.One of the purposes was to better understand the reasons why such a large ensemble had been established in a space now deprived, at the northwestern tip of the country. The complex includes the vestiges of several buildings, among which an early Christian basilica, a vaulted construction which served perhaps as a mausoleum, the remains of a “false rampart”, and of a series of parallel walls corresponding, at a certain period, to a dam, two underground halls, and numerous fragments of sculpted stones. A special attention was paid to the basilica and to the cemetery, where twenty-seven tombs were studied in detail. Another objective was to try to clarify the absolute and relative dating of the main buildings, as well as the function of many of them, which was still unclear. The mission also sought to specify the relationship which must have existed around the year one thousand between the religious complex and the medieval capital Ani, from which it is only some kilometers away.

Effect of Radiance-Dimmer Devices Simulating Natural Sunlight Rhythm on the Plasma Melatonin Levels and Anxiety and Depression Scores of the Submarine Personnel

Objective: Not perceiving circadian shifts of sunlight due to living in enclosed environments may have deleterious effects on mental health and plasma parameters. This study aimed to determine the effect of dim regulation on the submarine personnel of Iranian Navy forces by radiating devices according to natural circadian sunlight shifts. Also, this study aimed to investigate the impact of mimicking sunlight circadian by artificial radiance luminating devices on the serological and psychological measures of submarine personnel. Method : Participants were randomly assigned to experimental and control groups in this non-randomized controlled trial. There were 26 participants in each group, and they were all male aged 21-29 years. Both groups were living in the submarine underground hall, with 120 meters 2 area with constant radiance with the same intensity. The experimental group had been given extra lighting devices with changing radiance intensity according to the natural sunlight circadian cycles. Plasma melatonin levels and depression and anxiety scores were determined before and after the experiment for both groups. Minnesota Multiphasic Personality Inventory (MMPI) and Cattell's Anxiety Scale Questionnaire (IPAT) were used to measure depression and anxiety, respectively. Results: Findings indicate that the plasma melatonin levels (-16.2±13.6 vs 8.0±9.3 mg/dL, respectively; p<0.001), depression scores (-6±6 vs 3.9±5.4, respectively; p<0.001), and anxiety scores (-1±1.2 vs 0.73±1.04, respectively; p<0.001) significantly reduced in the experimental group compared to the control group. Conclusion: Using radiance dimmers, with a radiance intensity regularity according to the sunlight, is effective in improving psychiatric and plasma parameters and can be used in closed occupational environments such as underground environments and submarine halls.

Estimation Procedure of Influence Exerted by Trigger Effects in Rock Mass on Technical Condition of Long-Term Operated Underground Structures

Physical processes are initiated in rock mass by long-term induced vibration loads which give rise to triggering factors the neglect of which can result in instability of underground structures. The methodical characteristics of the trigger effect monitoring are described for the specific operating conditions of an underground powerhouse hall of a hydroelectric plant in the Kola Peninsula in Russia.

New Low-Background Laboratory in the Pyhäsalmi Mine, Finland

A new low-background laboratory has been constructed in the Pyhasalmi mine in central Finland and was commissioned in the beginning of 2017. The underground experimental hall is located at a depth of 1436 m corresponding to about 4100 m of water equivalent (m.w.e.). We describe the equipment of the laboratory and the backgrounds arising from the natural rock radioactivity and the flux of cosmic ray muons at the experimental hall location. The high-sensitivity experiments operating at the low-background laboratory are briefly described.

Water matters. Geoarchaeology of the city of Adria and palaeohydrographic variations (Po Delta, Northern Italy)

Adria is located in the northern Po delta at the edge of the Venice Lagoon, a sector of the Po Plain that was built by the late Holocene geomorphic activity of the Po, Adige and Tartaro rivers. Early settlements are dated to the Middle Bronze Age, and the city developed as a major urban centre during the Iron Age and Roman times. In the early Middle Ages, Adria survived as a local religious centre in the Venetian area, as evidenced by the existence of a 9th century AD church. The superimposition of archaeological deposits led to the upbuilding of an anthropogenic mound rising up to 5m above the surrounding plain. The aim of this investigation is to understand the evolution of the city of Adria from the 1st millennium BC to the Middle Ages, and its relationships with the rearrangement of the river network and connected palaeogeographic setting.The area was studied through the analysis of historical cartography, aerial photographs, a digital terrain model, archaeological data from the archives of the Soprintendenza Archeologia del Veneto, geological corings and a cone penetration test. New stratigraphic data have been acquired through the execution of 21 manual boreholes up to 5m in depth with an Edelman combination-type auger. Radiocarbon datings were carried out on selected peat samples.The analysis of the elevation above sea level of different stratigraphic data has exposed the stages of the evolution of the city, starting from the 6th century BC through Roman times and post-Antiquity, revealing the extension of the archaeological mound in the southern part of the modern city. The growth of the mound took place in four phases, dated to the 6th–5th centuries BC, 4th–3rd centuries BC, 1st century BC–1st century AD and post-Antiquity. The presence of a buried soil at the top of the Po deposits, coupled with radiocarbon dating of extensive peat layers, has allowed the reconstruction of the stratigraphy of the alluvial succession, and to correlate it with the archaeological record. The buried soil at the top of the Po deposits lies below the 6th century BC archaeological levels in the lowest part of the archaeological mound. On this same palaeosurface the first 9th century AD church was built. Two alluvial events buried this church under about 2m of overbank fines, turning it into an underground hall, known as the ‘crypt’ of the modern San Giovanni church. These alluvial events are attributed to the Tartaro River, with a probable contribution by the Adige River. The first alluvial event took place between the 9th and 11th centuries AD. In the 11th–15th centuries AD, a marshy area extended north, west and east of the city centre, as evidenced by an extensive peat layer that was buried by the second alluvial event later than the 15th century AD.

The detector system of the Daya Bay reactor neutrino experiment

The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent data has provided the world׳s most precise measurement of sin22θ13 and the effective mass splitting Δmee2. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world׳s most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes, the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors’ baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking.

Study on Fire Prevention Performance-Based Design of a Large Underground Banquet Hall

There is large fires risk and difficult evacuation in underground buildings, so it is necessary to study the development of fire and evacuation procedure in underground building. In this paper, a large underground banquet hall was chosen as an example, evacuation safety in the hall was analyzed by numerical simulation. First of all, fire model and two fire scenes were set up by using the software Fire Dynamics Simulator. Then the process of fire spread was reappeared by numerical simulation, and evacuation process was simulated by using the software PathFinderTM. By comparison with both result, it was proved that there is safe personnel evacuation in the case of effective fire-fighting facilities. According to the simulation results, reasonable recommendations about fire safety of the large banquet hall was proposed. The research will contribute to fire prevention and architecture design.

6545 Helicobacter pylori infection as an independent prognostic factor for locally advanced gastric cancer with curative resection

The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent data has provided the world׳s most precise measurement of sin22θ13 and the effective mass splitting Δmee2. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world׳s most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes, the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors’ baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking.

The module nuclear absorber of the ATLAS Hadron Calorimeter (An experiment of controlled assembly on the surface and underground)

The Hadron Calorimeter of the ATLAS spectrometric complex is a principal part of the whole setup. This paper describes the developed concept and methods for the controlled construction of a steel nuclear calorimeter absorber which provides calorimeter assembly on the surface and in the underground experimental hall meeting the required design tolerances.

The OPERA experiment in the CERN to Gran Sasso neutrino beam

The OPERA neutrino oscillation experiment has been designed to prove the appearance of ντ in a nearly pure νμ beam (CNGS) produced at CERN and detected in the underground Hall C of the Gran Sasso Laboratory, 730 km away from the source. In OPERA, τ leptons resulting from the interaction of ντ are produced in target units called bricks made of nuclear emulsion films interleaved with lead plates. The OPERA target contains 150000 of such bricks, for a total mass of 1.25 kton, arranged into walls interleaved with plastic scintillator strips. The detector is split into two identical supermodules, each supermodule containing a target section followed by a magnetic spectrometer for momentum and charge measurement of penetrating particles. Real time information from the scintillators and the spectrometers provide the identification of the bricks where the neutrino interactions occurred. The candidate bricks are extracted from the walls and, after X-ray marking and an exposure to cosmic rays for alignment, their emulsion films are developed and sent to the emulsion scanning laboratories to perform the accurate scan of the event. In this paper, we review the design and construction of the detector and of its related infrastructures, and report on some technical performances of the various components. The construction of the detector started in 2003 and it was completed in Summer 2008. The experiment is presently in the data taking phase. The whole sequence of operations has proven to be successful, from triggering to brick selection, development, scanning and event analysis.

200 days of Borexino data

Borexino is a large-volume liquid scintillator detector placed in the underground halls of the Laboratori Nazionali del Gran Sasso in Italy. After several years of construction, data taking started in May 2007, providing immediately incontrovertible evidence of the unprecedented radiopurity of the target mass. Here we report on the newest Borexino results obtained with about 200 days of data. Borexino provides the first direct measurement of the solar neutrino survival probability in both vacuum-dominated and matter-enhanced regions provided by a single experiment. The interaction rate of the 0.862 MeV 7 Be solar neutrinos is found to be 49 ± 3 stat ± 4 sys counts/(day⋅100 tons), in agreement with the oscillation hypothesis in the MSW Large Mixing Angle scenario. The first real-time measurement of the 8 B solar neutrinos above 2.8 MeV provides interaction rate of 0.26 ± 0.04 stat ± 0.02 sys counts/(day⋅100 tons). These measurements improve the experimental determination of the flux of the pp and CNO solar neutrinos, and the limit on the effective magnetic moment using solar neutrinos.

The instrumented magnets for the OPERA experiment: construction and commissioning

The design and construction of the 990-ton gapless iron magnets for the OPERA experiment represent a major challenge from the point of view of mechanics, electric and heat engineering. Two of such magnets have been built in a deep underground hall of the Gran Sasso laboratories between 2003 and 2006 and they have been switched on for the first time in March 2006. In this paper we discuss the construction and characterization of these devices. First experience with the CNGS beam are also reported.

Development and utilization of underground space for the protection of relics in the Yang Emperor Mausoleum of the Han Dynasty

By analyzing the ten burials that have been unearthed at the Yang Emperor Mausoleum of the Han Dynasty, and China’s first wholly underground protection and exhibition hall of relics that is under construction, the article expounds the importance of relic site protection through underground space. In particular, it discusses the preservation of historical and cultural relics, the harmonious relationship between architecture and nature, and the collection and security of cultural relics.

A Beta Beam complex based on the machine upgrades for the LHC

The beta beam CERN design is based on the present LHC injection complex and its physics reach is mainly limited by the maximum rigidity of the SPS. In fact, some of the scenarios for the machine upgrades of the LHC, particularly the construction of a fast cycling 1 TeV injector (“Super-SPS”), are very synergic with the construction of a higher γ beta beam. At the energies that can be reached by this machine, we demonstrate that dense calorimeters can already be used for the detection of ν at the far location. Even at moderate masses (40 kton) as the ones imposed by the use of existing underground halls at Gran Sasso, the CP reach is very large for any value of θ13 that would provide evidence of νe appearance at T2K or NOνA (θ13≥3°). Exploitation of matter effects at the CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy in significant areas of the θ13-δ plane.

Stability appraisal of the Medvedova konta pothole

Until 1956 the underground details of areas around Pokljuka were practically unknown due to the area’s non-karstic outward appearance. However, the presence of karst phenomena on this Alpine plain is undoubtedly indicated, primarily by the absence of a surface drainage network. A mathematical model was made of the Medvedova konta pothole, in which two different sets of material properties were used, corresponding to the Triassic limestone that forms the bedrock under the greater part of Pokljuka. The model simulates the gradual thinning of the ceiling of the underground hall, from the surface downwards, until its collapse. The paper presents a stability appraisal of the Medvedova konta pothole in Pokljuka.

Mixed handedness in familial and non-familial schizophrenia

The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of ν¯e oscillations over km-baselines. Subsequent data has provided the world׳s most precise measurement of sin22θ13 and the effective mass splitting Δmee2. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world׳s most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes, the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors’ baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking.

Energy losses of magnetic monopoles and of dyons in the earth

In this paper we discuss the energy losses of magnetic monopoles and of dyons in the earth's core and mantle over a large range of velocities. The calculations are used to compute the maximum fractional geometrical acceptance for a detector located in one of the underground halls at the Gran Sasso laboratory in central Italy.