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The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kton multi-purpose liquid scintillator detector currently being built in a dedicated underground laboratory in Jiangmen (PR China). JUNO’s main physics goal is to determine the neutrino mass ordering using electron anti-neutrinos from two nuclear power plants at a baseline of about 53 km. JUNO aims for an unprecedented energy resolution of 3% at 1 MeV for the central detector, with which the mass ordering can be measured with 3 – 4 σ significance within six years of operation. Most neutrino oscillation parameters in the solar and atmospheric sectors can also be measured with an accuracy of 1% or better. Furthermore, being the largest liquid scintillator detector of its kind, JUNO will monitor the neutrino sky continuously for contributing to neutrino and multi-messenger astronomy. JUNO’s design as well as the status of its construction will be presented, together with a short excursion into its rich R&D program.

The VIP2 (VIolation of the Pauli Exclusion Principle) experiment at the Gran Sasso underground laboratory (LNGS) is searching for possible violations of standard quantum mechanics predictions in atoms at very high sensitivity. We investigate atomic transitions with precision X-ray spectroscopy in order to test the Pauli Exclusion Principle (PEP) and therefore the related spin-statistics theorem. We will present our experimental method for the search for "anomalous" (i.e. Pauli-forbidden) X-ray transitions in copper atoms, produced by "new" electrons, which could have tiny probability to undergo Pauli-forbidden transition to the ground state already occupied by two electrons. We will describe the VIP2 experimental setup, which is taking data at LNGS presently. The goal of VIP2 is to test the PEP for electrons with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10$^{-31}$. We will present current experimental results and discuss implications of a possible violation., Comment: Proceedings of DICE 2018 Conference

This paper reports a brief introduction to Deep Underground Laboratories (DULs) and the connection they have with research on biology in extreme environments and the effect of radiation in life. Presently, there are 14 DULs in operation worldwide. Although the main research activity in these infrastructures concerns the search for rare events in astroparticle physics and neutrino physics, DULs offer a unique opportunity to undertake experiments in astrobiology and biology in extreme environments. This is the main motivation of Deep Underground Laboratory Integrated Activity in biology (DULIA-bio) 2019 Workshop, which was held at the Gran Sasso (Italy) underground laboratory. This paper aims to give an introduction to the subject of the Workshop by reviewing the main features of DULs.

The paper presents results of multivariate analysis of variations of radon concentrations in the shallow underground laboratory and a family house, depending on meteorological variables only. All available multivariate classification and regression methods, developed for data analysis in high-energy physics and implemented in the toolkit for multivariate analysis (TMVA) software package in ROOT, are used in the analysis. The result of multivariate regression analysis is a mapped functional behaviour of variations of radon concentration depending on meteorological variables only, which can be used for the evaluation of radon concentration, as well as to help with modelling of variation of radon concentration. The results of analysis of the radon concentration variations in the underground laboratory and real indoor environment, using multivariate methods, demonstrated the potential usefulness of these methods. Multivariate analysis showed that there is a potentially considerable prediction power of variations of indoor radon concentrations based on the knowledge of meteorological variables only. In addition, the online system using the resulting mapped functional behaviour for underground laboratory in the Institute of Physics Belgrade is implemented, and the resulting evaluation of radon concentrations are presented in this paper.

In France, a framework has been drawn up by the National Assembly and implemented by the government, in order to get the best relationship between Andra, among others, and the stakeholders and the inhabitants of the towns and countries where disposal facilities or projects are or could be established. The main threads of the two Acts passed in 2006, being relevant to the relationship with inhabitants are the information exchange and the local economic development. Dealing with the information exchange and diffusion: • The Local Information Committee (CLI), for each nuclear facility, has been reinforced and a specific, Local Information and Oversight Committee (for the Underground Laboratory in Meuse-Haute-Marne) has been renewed. The CLI was in charge of a general assignment to inform and consult on nuclear safety, radioprotection and environmental topics. Now, since 2006, the nuclear facility’s CLI and the CLIS are able to order study reports, measures and analyses to experts freely selected. • Creation of the High Committee for Transparency and Information on Nuclear Safety (HCTISN). This new authority aims to inform, consult and debate about the risks relevant to nuclear activities and their impacts on people’s health, environment and nuclear safety. Andra contributes to the functioning of CLI in disposal facilities at Manche and Aube Departments, and CLIS of the underground Laboratory at Meuse and Haute-Marne departments. This paper will present these contributions and how Andra’s action helps to reach the goals of information and exchange with the people around its facilities. Concerning the local economic development, there are specific organizations or schemes, depending on the facility: • Local taxes contributions based on the disposal facilities activities as is usual in France. • A High Level Committee (CHN) and two public interest groups (GIP) in Meuse and Haute-Marne departments have been set up since 1991 and 2005. Andra is represented in these three institutions, but they are not funded at all by Andra. This paper will show the Andra’s involvement in the local economic and territorial developments. Within this general framework Andra has developed information and exchanges actions with the stakeholders and the inhabitants around its facilities. Examples of these actions will be presented also.Copyright © 2010 by ASME

The gamma-ray background problem is known to be acute in any low-background underground experiment. The variations of this background depend on many parameters and should be taken into account when interpreting the results of experiments combined under the term “underground physics”. This paper is devoted to studying the long-term variations of the gamma-ray background in an underground laboratory with a scintillation detector based on a CsI crystal. Our studies have revealed a new effect in underground physics—a delayed nonlinear pumping effect for the gamma-ray background in an underground room that can lead to a significant rise of this background at an anomalously low atmospheric pressure.

In the model test of underground engineering, how to carry out the automatic excavation of different types of tunnel and small caverns is still a technical challenge at present. In this paper, we designed and developed the micro automatic excavation device, including the cutting type automatic excavation device and the crushing type automatic excavation device for model test of underground engineering by using servo electric control technology. The device has high excavation accuracy. With the aid of this device, the excavation of cavern with any shape can be conducted. This device can carry out not only full section automatic excavation, but also bench method automatic excavation. The device has been successfully applied in the three-dimensional geomechanical model test of the excavation for the cavern groups in an underground laboratory. After the excavation of the model cavern, the wall of the cavern is smooth, and the intersection position and angle between the caverns are accurate. Compared with the design size, the excavation error of all caverns is within ± 5 ‰, which meets the design requirements. It provides technical support for accurate excavation test of model test meanwhile provides a strong technical guarantee for the fine simulation of the deformation characteristics and failure laws of deep underground caverns.

Underground laboratories provide a unique environment for various industries and are a suitable place for developing new technologies for mining, geophysical surveys, radiation detection, as well as many other studies and measurements. Unfortunately, any operation in underground excavations is associated with exposure to many hazards not necessarily encountered in surface laboratories. One of the most dangerous events observed in underground conditions is the dynamic manifestation of rock mass pressure in form of rockburst, roof falls and mining tremors. Therefore, proper evaluation of geomechanical risk is a key element ensuring the safety of work in underground conditions. Finite Element Method-based numerical analysis is one of the tools which allow conducting a detailed geomechanical hazard assessment already at the object design stage. The results of such calculations may be the basis for the implementation of preventive measures before running up the underground facility.Within this paper, the three-dimensional FEM-based numerical analysis of large-scale underground laboratory located in deep Polish copper mine was presented. The calculations were made with GTS NX software, which allowed determining the changes in the safety factor in surrounding of the analyzed area. Finally, the possibility of underground laboratory establishment, with respect to predicted stress and strain conditions, were determined.

The Korean Atomic Energy Research Institute is currently planning the construction of an Underground Research Laboratory to carry out research and development related to the disposal of high-level wastes from nuclear reactors used to generate electrical power. This paper discusses the excavation methods used to construct the Canadian Underground Research Laboratory and their application in planning for the construction of a similar underground laboratory and eventually an underground repository for high-level wastes in Korea. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. "Reprinted with permission from Elsevier".

Intrinsic radiation of materials is one of the major backgrounds for many rare-event search experiments. Thus, the production of pure materials in an underground laboratory is a promising approach for eliminating cosmogenic radionuclides. In this paper, we demonstrate a procedure to evaluate the yields of cosmogenic radionuclides in copper and germanium in the second phase of the China Jinping Underground Laboratory. Our results show that for copper and germanium materials, the largest cosmogenic background comes from $$^{3}$$H and $$^{57,58,60}$$Co, and $$^{3}$$H and $$^{68}$$Ge, respectively, which all have yields on the order of $$10^{-7} \;{\mathrm {kg}}^{-1}\,{\mathrm {day}}^{-1}$$. The corresponding radioactivities after 90 days pf exposure underground are estimated to be lower than 10−6 μBq kg−1.

COSINE-100 is a direct detection dark matter search experiment that uses a 106 kg array of eight NaI(Tl) crystals that are kept underground at the Yangyang Underground Laboratory to avoid cosmogenic activation of radioisotopes by cosmic rays. Even though the cosmogenic activity is declining with time, there are still significant background rates from the remnant nuclides. In this paper, we report measurements of cosmogenic isotope contaminations with less than one year half-lives that are based on extrapolations of the time dependent activities of their characteristic energy peaks to activity rates at the time the crystals were deployed underground. For longer-lived 109Cd ( T 1 / 2 = 1.27 y) and 22Na ( T 1 / 2 = 2.6 y), we investigate time correlations and coincidence events due to several emissions. The inferred sea-level production rates are compared with calculations based on the ACTIVIA and MENDL-2 model calculations and experimental data. The results from different approaches are in reasonable agreement with each other. For 3H, which has a long, 12.3 year half-life, we evaluated the activity levels and the exposure times that are in reasonable agreement with the time period estimated for each crystal’s exposure.

Pacific Northwest National Laboratory has accumulated years of data with ultra-low-background proportional counters collected in an on-site shallow underground laboratory. This large dataset of events is exploited to study the impact of using neural networks for data analysis compared to simple pulse shape discrimination (PSD). The PSD method can introduce false positives for overlapping event distributions; however, a neural network can separate and correctly classify these events. This paper describes the training, testing, and validation of a neural network, analysis of challenge datasets, and a comparison between the standard PSD approach and a dense, fully-connected neural network.

Since a few years there are well-type HPGe-detectors with a small, point-like, anode contacts available commercially. This paper describes the characterisation of the first ultra low-background, so-called, SAGe™ well detector with regards to resolution and background performance. Inside a passive lead/copper shield in the underground laboratory HADES a background count rate of 690 ± 6d-1 (268 ± 3d-1 per kg Ge) was recorded 19 months after taking it underground.

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China’s Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel’s side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

The direct measurement of the \(^{13}{\hbox {C}}\)(\(\alpha \),n)\(^{16}{\hbox {O}}\) nuclear reaction down to its Gamow window is essential to the complex understanding of the astrophysical s-process, which is responsible for the production of about half of the heavier elements above the iron group. The combination of a high efficiency experimental setup and the extremely low environmental background is required to measure cross sections of the order of picobarns. This paper presents the main features of the LUNA neutron detector array dedicated to the direct investigation of the \(^{13}{\hbox {C}}\)(\(\alpha \),n)\(^{16}{\hbox {O}}\) nuclear reaction in the Underground Laboratory of LNGS.

The COBRA demonstrator, a prototype for a large-scale experiment searching for neutrinoless double beta-decay, was built at the underground laboratory Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It consists of an array of 64 monolithic, calorimetric CdZnTe semiconductor detectors with a coplanar-grid design and a total mass of 380g. It is used to investigate the experimental challenges faced when operating CdZnTe detectors in low-background mode, to identify potential background sources and to show the long-term stability of the detectors. The first data-taking period started in 2011 with a subset of the detectors, while the demonstrator was completed in November 2013. To date, more than 250kg d of data have been collected. This paper describes technical details of the experimental setup and the hardware components., 8 pages, 10 figures, submitted to NIM A