Search

China JinPing underground Laboratory (CJPL) was established inside the tunnels piercing Jinping Mountain in Sichuan Province, China, which can provide an ideal environment for low background experiment. Jinping Underground laboratory for Nuclear Astrophysics (JUNA) is one of the major research programs in CJPL. A new 400 kV accelerator, with high current based on an ECR source, will be installed into CJPL for the study of key nuclear reactions in astrophysics. The beam characteristics of the accelerator, like absolute energy, energy spread, and long-term energy stability, will be determined by several well-known resonance and non-resonance reactions. Due to the new accelerator still being under construction, the resonance reaction of 27Al(p, γ)28Si and non-resonance 12C(p, γ)13N were studied at the 320 kV high-voltage platform of Institute of Modern Physics in Lanzhou, China. The energy spread of proton beam is about 1.0 keV and the long-term energy stability of proton beam is better than ±200eV during 4 hours measurement.

Suppression of radon background is one of main tasks in ultra-low background experiments. The most promising technique for suppression of radon is its adsorption on charcoal. Within the frame of the NEMO-3 experiment, radon trapping facility (RTF) was installed in Modane underground laboratory in 2004. Based on long-term experience with this facility a new compact transportable anti-radon facility was constructed in cooperation among IEAP CTU, SURO and ATEKO company. The device provides 20m3/h of purified air (air radon activity at the output ∼10mBq/m3). The basic features and preliminary results of anti-radon device testing are presented.

The Belgrade underground laboratory is a shallow underground one, at 25 meters of water equivalent. It is dedicated to low-background spectroscopy and cosmic rays measurement. Its uniqueness is that it is composed of two parts, one above ground, the other bellow with identical sets of detectors and analyzing electronics thus creating opportunity to monitor simultaneously muon flux and ambient radiation. We investigate the possibility of utilizing measurements at the shallow depth for the study of muons, processes to which these muons are sensitive and processes induced by cosmic rays muons. For this purpose a series of simulations of muon generation and propagation is done, based on the CORSIKA air shower simulation package and GEANT4. Results show good agreement with other laboratories and cosmic rays stations.

Over the past several decades, fundamental physics experiments have required access to deep underground laboratories to satisfy the increasingly strict requirements for ultra-low background environments and shielding from cosmic rays. In this presentation, I summarize the existing and anticipated physics programs and laboratory facilities of North America’s deep facilities: The Soudan Underground Laboratory in Minnesota, SNOLab in Ontario, Canada, and the Sanford Underground Research Facility in Lead, South Dakota.

We are currently setting up a facility for low-background gamma-ray spectrometry based on a HPGe detector. It is dedicated to material screening for the XENON and DARWIN dark matter projects as well as to the characterization of meteorites. The detector will be installed in a medium depth ($\sim$620 m.w.e.) underground laboratory in Switzerland with several layers of shielding and an active muon-veto. The GeMSE facility will be operational by fall 2015 with an expected background rate of $\sim$250 counts/day (100-2700 keV)., Comment: The following article appeared in AIP Conf. Proc. 1672, 120004 (2015) and may be found at http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4928010. The muon spectrum in Figure 4 (left) was corrected due to a bug in the code. After correction the muon flux is reduced by a factor of about 3

Protection from and rejection of backgrounds is a key issue for the EDELWEISS-III direct dark matter detection experiment which aims at exploring the 10−9 pb cross-section region for spin-independent WIMP-nucleon interaction. The detector is located in the low radioactivity environment of the Modane Underground Laboratory and consists of 36 advanced FID germanium detectors operating at 18 mK in a dilution refrigerator in order to identify eventual rare nuclear recoils induced by elastic scattering of WIMPs from our Galactic halo. I will discuss the background and the methods of rejecting it with the FID detectors. Detector performances and the first analysis of data acquired in a long-term campaign will be presented as well. The FID detector technology is not limited to EDELWEISS-III but can further be employed in the next generation of cryogenic detector experiments.

Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

The CRESST experiment is set up in the Gran Sasso Underground Laboratory to search for hypothetical Weakly Interacting Massive Particles (WIMPs) with cryogenic detectors. It is expected that WIMPs can transfer a part of their energy (up to some tens of keV) via scattering off a nucleus of an absorber. In order to detect these small energies Superconducting Phase transition Thermometers (SPTs) are used at very low temperatures. In this article the principle of the SPTs is introduced. The techniques to produce SPTs with a reproducible transition temperature of 15±5 mK are shown.

Impressive progress has been made in the course the last decades in understanding astrophysical objects. Increasing precision of nuclear physics data has contributed significantly to this success, but now a better understanding of several important findings is frequently limited by uncertainties related to the available nuclear physics data. Consequently it is desirable to improve significantly the quality of these data. An important step towards higher precision is an excellent signal to background ratio of the data. Placing an accelerator facility inside an underground laboratory reducing the cosmic ray induced background by six orders of magnitude is a powerful method to reach this goal, even though careful reduction of environmental and beam induced background must still be considered. Experience in the field of underground nuclear astrophysics has been gained since 20 years due to the pioneering work of the LUNA Collaboration (Laboratory for Underground Nuclear Astrophysics) operating inside the unde...

Rejection and protection from background is a key issue for the next generation SuperCDMS SNOLAB experiment that will have a cross-section sensitivity of better than 8 × 10−46 cm2 for spin-independent WIMP-nucleon interactions. This paper presents the details of the methods used to reject electromagnetic backgrounds using the new iZIP detectors that are currently operated in the Soudan Underground Laboratory, MN and the methods the collaboration is investigating to protect against neutron background in the next generation SuperCDMS experiment.

In the course of 2012, a facility for the fast screening of germanium detectors called HEROICA (Hades Experimental Research Of Intrinsic Crystal Appliances) has been installed at the HADES underground laboratory in the premises of the Belgian Nuclear Research Centre SCK•CEN, in Mol (Belgium). The facility allows performing a complete characterization of the critical germanium detectors' operational parameters with a rate of about two detectors per week.

ICARUS-T600 is the first large mass Liquid Argon TPC (∼ 600 t) exposed to CNGS ν beam and collecting cosmic rays since May 2010 at the INFN-LNGS underground laboratory. Results on 2010 and 2011 runs with CNGS neutrino beam are presented, together with the recent precision measurement of the neutrino velocity with the 2012 data. Perspectives on a sterile neutrino search at CERN with a double LAr-TPC detectors complemented by magnetic spectrometers are also presented in the framework of the recently comeback sterile neutrino puzzle.

This talk reviews the major underground physics facilities in North America as of 2010. The Sanford Underground Laboratory and proposed DUSEL are reviewed in a separate talk.

Radon detectors have been deployed underground at the Sanford Underground Laboratory at the site of the former Homestake Mine in Lead, SD. Currently, no radon mitigation measures are in place in the underground environment, and the continuing evolution of the facility ventilation systems has led to significant variations in early airborne radon concentrations. The average radon concentration measured near the primary ventilation intake for the 4850-ft level (Yates shaft) is 391 Bq/m{sup 3}, based on approximately 146 days of data. The corresponding average radon concentration near the other main ventilation intake for the 4850-ft level (Ross shaft) is 440 Bq/m{sup 3} based on approximately 350 days of data. Measurements have also been collected near the 1250-ft level Ross shaft, with average radon concentrations at 180 Bq/m{sup 3}. Secondary factors that may increase the baseline radon level underground include the presence of iron oxide and moisture, which are known to enhance radon emanation. The results of the current radon monitoring program will be used for the planning of future measurements and any potential optimization of ventilation parameters for the reduction of radon in relevant areas underground.

The project of the first Polish underground laboratory SUNLAB, in the Polkowice‐Sieroszowice copper mine, belonging to the KGHM Polska Miedź S.A. holding, is presented. Two stages of the project are foreseen: SUNLAB1 (a small laboratory in the salt layer exhibiting extremely low level of natural radioactivity) and SUNLAB2 (a big laboratory in the anhydrite layer, able to host the next generation liquid argon detector—GLACIER, which is considered within the LAGUNA FP7 project). The results of the natural radioactivity background measurements performed in the Polkowice‐Sieroszowice salt cavern are also briefly summarized.

The WArP Collaboration is getting ready to run the WArP 100 liter detector in the Underground laboratory in Gran Sasso, Italy. The new detector, scheduled to run in 2008, should improve the current sensitivity limits by a factor of 10. Meanwhile, an active R&D program is being conducted. The highlights of this program, namely the runs with Argon depleted in the radioactive isotope 39Ar currently in preparation and the measurements of the effects of contamination with Nitrogen and Oxygen on the Liquid Argon effective light yield will be presented as well as the current status of the 100 liter detector.

We give here an update on the CUORE cryogenic system. It consists of a large cryogen‐free cryostat cooled by five pulse tubes and one high‐power specially designed dilution refrigerator built by Leiden Cryogenics. The cryostat design has been completed and it is presently under construction. The site at the Gran Sasso Underground Laboratory is ready for the installation of the cryostat which is expected to begin by the end of 2009. We discuss here the preliminary results obtained on the performance of the mechanical cryorefrigerators. We also present a measurement of the residual heat leak of the copper which has been selected for the cryostat fabrication.

This paper reviews solar neutrino observations giving emphasis to measurements carried out at the Gran Sasso underground laboratory. Characteristics of solar neutrinos are reported. Observations are discussed together with a recent controversy between the Solar Standard Model predictions and the helioseismology. The impact of future solar neutrino measurements and the role of the Gran Sasso laboratory are discussed.

After a brief review of the main scientific motivations of LAGUNA, European cooperation projects (GLACIER, LENA and MEMPHYS), and of the virtues of the Frejus site, a preliminary feasibility study for a Megaton‐scale Underground Laboratory at Frejus is presented and its positive results discussed. The need for a future more detailed investigation (Design Study), which will be performed in the framework of the LAGUNA collaboration, is stressed. The excellent opportunity presented by the recently approved Frejus Safety Tunnel (d = 8 m) project is also underlined.

The results obtained in the measurement of the low level radiation background by using a thermoluminescent (TL) system, in a former salt mine, designed to be used as an underground laboratory , are presented.

The NEMO3 detector is mainly devoted to the search for the neutrinoless double beta decay (0{nu}{beta}{beta}). The detector is located in the Frejus underground laboratory, where it operates since February 2003. The detector contains several isotopes, the most abundant are {sup 100}Mo ({approx}7 kg) and {sup 82}Se ({approx}1 kg). Up to now no evidence for 0{nu}{beta}{beta} decay has been observed. The corresponding limits at 90% C.L. for the half-life are T{sub 1/2}{sup 0{nu}}>5.8x10{sup 23} years for {sup 100}Mo and T{sub 1/2}{sup 0{nu}}>2.1x10{sup 23} years for {sup 82}Se. The half-lives of the two-neutrino double-beta decay (2{nu}{beta}{beta}) for {sup 100}Mo, {sup 82}Se, {sup 116}Cd, {sup 150}Nd, {sup 96}Zr and {sup 48}Ca are also presented in this paper.

The KIMS experiment searches for for WIMP using CsI(Tl) crystal detectors in an underground laboratory in Korea. We present the first limit for WIMP search using one CsI(Tl) crystal and the future prospect of the search at the full capacity of CsI(Tl) crystals.

Dark matter search with CsI(Tl) crystals have been carrying out in the YangYang underground laboratory by KIMS group. The main effort of KIMS is the development of low background CsI(Tl) crystal detectors for WIMP search. By the successful reduction of internel background we could grow the low background CsI(Tl) crystals. We will present the first result obtained with one of low background crystal detector and the future prospect of WIMP search.

The Henderson Mine, operated by the Climax Molybdenum Company, is one of two sites under consideration by NSF to host a Deep Underground Science and Engineering Laboratory (DUSEL). Henderson, in the Rocky Mountains west of Denver, is an active molybdenum mine with large access shafts and high rock processing and removal capability.

The Modane Underground Laboratory, with an overburden of 4800 m.w.e, offers an excellent site for experiments requiring a low‐background environment. The laboratory is currently hosting experiments in particle and astroparticle physics and low‐level germanium gamma‐ray spectrometry activities. This paper sketchs the main characteristics, scientific activities and facilities of the laboratory as well as its insertion in the European program ILIAS. Special emphasis is given to the description of the low radioactivity measurements and Germanium detectors.

The prototype of the Borexino solar neutrino experiment is a low counting rate detector located at the underground Gran Sasso Laboratory. The detector was designed and built to achieve ultra‐purity in an organic liquid scintillator on a massive scale. A number of ancillary plants and screening facilities are needed to reach low background in the sub‐MeV region. The detector and its screening facilities are briefly described in this paper.

KIMS is an experimental group searching for dark matter in an underground laboratory in Korea. Major effort of KIMS has been devoted for the development of low background CsI(Tl) crystal detectors with low threshold for the direct WIMP search. An underground laboratory utilizing the space in a tunnel of Yangyang Pumped Storage Power Plant is established. We present the first result obtained with one crystal detector and the future prospect of WIMP search as well as other research activities carried out by KIMS.

We discuss the prospects for detecting nu_{mu,tau} and nu_{tau}neutrinos from Type II supernovas using the novel detector at the Supernova Burst Observatory (SNBO) or OMNIS that is being designed for an underground laboratory in the USA. This detector would collect ~2000 flavor selected events from a Galactic supernova and could probe neutrino mass down to a few eV, as well as the dynamics of the supernova process. We believe this is essential to further our understanding of the neutrino section of elementary particle physics., Comment: 4 pages containing 5 figures, 4 tables; workshop on Next Generation Nucleon Decay and Neutrino Detectors, NNN99 (SUNY at Stony Brook, NY, Sept. 23-25, 1999), and to be published by the American institute of Physics

The contribution focuses on the 400 kV accelerator which will be installed in the underground laboratory of the Laboratori Nazionali del Gran Sasso (Italy) in the year 2000. Special emphasis will bes put on the properties of the accelerator and the gamma detector systems giving high detection efficiency and low background.

A new underground laboratory is being built in a deep mine in Phyasalmi in the middle of Finland. This site provides excellent opportunities for underground physics, with the equivalent depth being about 4000 m.w.e., and no severe problems with background or instabilities. The first experiment in the mine consists of three small muon telescopes at different depths. New experiments are planned, the next one is probably a multipurpose muon detector at shallow depth.

The 2β decay experiment (about 30000 h) with 116CdWO4 scintillators enriched in 116Cd to 83% has been performed in the Solotvina Underground Laboratory. The limits T0ν1/2≥2.9⋅1022y (90% CL) and T2ν1/2≥1.8⋅1019y(99% CL) have been set for 0ν2β and 2ν2β decay of 116Cd. After substraction of the spectrum of natural CdWO4 scintillator from the spectrum of enriched 116CdWO4 detector the positive effect has been seen which is in accordance with 2ν2β decay of 116Cd with T2ν1/2= {2.70.5−0.4(stat.)+0.9−0.6(syst.)}⋅1019y. However the imitation of the effect by the impurities of 90Sr cannot be excluded.

A large tank of water, instrumented with photomultipliers and surrounded by an active shield using proportional wire tubes is being constructed in an underground laboratory at Park City, Utah. Baryon decay can be separated from background using the Cherenkov light pattern to a lifetime of approximately 4×1032 years in three years of running time. The status of the experiment, is reported here.

This paper presents the final solution adopted for the ‘‘Gran Sasso’’ Underground Laboratory.