The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), Fr\'ejus (France/Italy), Pyh\"asalmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The design study aims at the comprehensive and coordinated technical assessment of each site, at a coherent cost estimation, and at a prioritization of the sites within the summer 2010.Comment: 5 pages, contribution to the Workshop "European Strategy for Future Neutrino Physics", CERN, Oct. 200

A detection system to measure muon-induced neutrons for direct Dark Matter searches

International audienceMuon-induced neutrons constitute a prominent background component in a number of low count rate experiments, namely direct searches for Dark Matter. In this work we describe a neutron detector to measure this background in an underground laboratory, the Laboratoire Souterrain de Modane. The system is based on 1 m of Gd-loaded scintillator and it is linked with the muon veto of the EDELWEISS-II experiment for coincident muon detection. The system was installed in autumn 2008 and passed since then a number of commissioning tests proving its full functionality. The data-taking is continuously ongoing and a count rate of the order of 1 muon-induced neutron per day has been achieved

A new high-background-rejection dark matter Ge cryogenic detector

A new design of a cryogenic germanium detector for dark matter search is presented, taking advantage of the coplanar grid technique of event localisation for improved background discrimination. Experiments performed with prototype devices in the EDELWEISS II setup at the Modane underground facility demonstrate the remarkably high efficiency of these devices for the rejection of low-energy $\beta$, approaching 10$^5$ . This opens the road to investigate the range beyond 10$^{-8}$ pb in the WIMP-nucleon collision cross-sections, as proposed in the EURECA project of a one-ton cryogenic detector mass.Comment: submitted to Physical Review Letter

The LAGUNA design study- towards giant liquid based underground detectors for neutrino physics and astrophysics and proton decay searches

The feasibility of a next generation neutrino observatory in Europe is being considered within the LAGUNA design study. To accommodate giant neutrino detectors and shield them from cosmic rays, a new very large underground infrastructure is required. Seven potential candidate sites in different parts of Europe and at several distances from CERN are being studied: Boulby (UK), Canfranc (Spain), Fr\'ejus (France/Italy), Pyh\"asalmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The design study aims at the comprehensive and coordinated technical assessment of each site, at a coherent cost estimation, and at a prioritization of the sites within the summer 2010

Production of ultra clean coal, Part III. Effect of coal’s carbonaceous matrix on the dissolution of mineral matter using hydrofluoric acid

An Australian bituminous coal was treated with increasing concentrations of hydrofluoric acid (HF), and the extraction levels of Al, Si, Fe, Ti, K, Na, Ca and Mg were determined. These extraction levels were compared to those obtained when the mineral matter alone, produced by ashing the coal at a low temperature, was treated with HF, in order to quantify the extent that the carbonaceous matrix inhibits extraction. The carbonaceous matrix inhibits the dissolution of Ti to a large extent. Si and Fe are the next most inhibited elements. It is proposed that the Ti is present as extremely small particles, of possibly less than 1 mum in length, which are finely disseminated throughout the coal

Production of Ultra Clean Coal, Part II – Ionic equilibria in solution when mineral matter from black coal is treated with aqueous hydrofluoric acid

A model fur determination of the concentration of fluoride complexed aluminium and silicon species, free fluoride (F-), II+ ions and molecular HF in solution when aluminosilicate compounds are treated with aqueous HF is presented. The model elucidates chemical mechanisms governing both the dissolution behaviour of the mineral matter in coal towards aqueous HF, and the unwanted precipitation of various fluoride compounds, such as CaF2, MgF2 and NaAIF(4). The controlling parameter for the precipitation of fluoride compounds is the free F- concentration in solution. The model has application toward the development of chemical strategies for dissolving virtually all of the mineral matter from coal and avoiding the unwanted precipitation of fluoride compounds. The model also has application toward the development of a strategy for recovering fluoride from spent leaching solutions. Ultimately, this work will assist in the development of a process for the production of Ultra Clean Coal (UCC) containing less than 0.1% by weight mineral matter