Radiation Tolerance Tests of Ultrasonic Oxygen Deficiency Sensors

The Large Hadron Collider (LHC), presently under construction at CERN, will contain about 96 tons of high-density helium (liquid and supercritical), mostly located in the underground components of the LHC machine. To detect a dangerous decrease of oxygen concentration in the atmosphere caused by a potential release of helium, the Oxygen Deficiency Hazard Detection system will be applied for the LHC operation in the tunnel and other selected areas. The oxygen concentration is derived on the assumption that the gas added to the air is helium alone. A novel concept of oxygen deficiency detection system, built at the Wroclaw University of Technology (WUT) in Poland, allows verifying the oxygen concentration in the air by means of sound velocity measurements. The paper describes the design and functionality of two prototypes of ultrasonic ODH detection system tested by the WUT. In order to qualify the systems to be used in the LHC tunnel, the stability of ultrasonic transducers and electronics has been checked under radiation in an environment similar to that predicted for the LHC. At the beginning both systems have been tested in TCC2 test radiation zone at CERN. The complementary test, was performed in Institute of Atomic Energy (IEA) in Poland

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

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

Guidelines for diagnosis and management of the cobalamin-related remethylation disorders cblC, cblD, cblE, cblF, cblG, cblJ and MTHFR deficiency

BACKGROUND: Remethylation defects are rare inherited disorders in which impaired remethylation of homocysteine to methionine leads to accumulation of homocysteine and perturbation of numerous methylation reactions. OBJECTIVE: To summarise clinical and biochemical characteristics of these severe disorders and to provide guidelines on diagnosis and management. DATA SOURCES: Review, evaluation and discussion of the medical literature (Medline, Cochrane databases) by a panel of experts on these rare diseases following the GRADE approach. KEY RECOMMENDATIONS: We strongly recommend measuring plasma total homocysteine in any patient presenting with the combination of neurological and/or visual and/or haematological symptoms, subacute spinal cord degeneration, atypical haemolytic uraemic syndrome or unexplained vascular thrombosis. We strongly recommend to initiate treatment with parenteral hydroxocobalamin without delay in any suspected remethylation disorder; it significantly improves survival and incidence of severe complications. We strongly recommend betaine treatment in individuals with MTHFR deficiency; it improves the outcome and prevents disease when given early

Technical and economic aspects of oxygen separation for oxy-fuel purposes

Oxy combustion is the most promising technology for carbon dioxide, originated from thermal power plants, capture and storage. The oxygen in sufficient quantities can be separated from air in cryogenic installations. Even the state-of-art air separation units are characterized by high energy demands decreasing net efficiency of thermal power plant by at least 7%. This efficiency decrease can be mitigated by the use of waste nitrogen, e.g., as the medium for lignite drying. It is also possible to store energy in liquefied gases and recover it by liquid pressurization, warm-up to ambient temperature and expansion. Exergetic efficiency of the proposed energy accumulator may reach 85%

The Applicability of Ultrasonic Oxygen Deficiency Hazard Detectors in the LHC Accelerator Tunnel

The Large Hadron Collider (LHC), will contain about 96 tonnes of high-density helium, mostly located in the underground components of the LHC machine. Some of potential LHC cryogenic system failures might be followed by helium discharge to the tunnel and potential decrease of the oxygen concentration below the safety level of 18% cannot be excluded. A novel concept for oxygen deficiency detection can be based on measurements of sound velocity in the atmosphere. The paper presents the test results of ultrasonic ODH detection prototype system in radiation environment similar to that predicted for the LHC

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), Fréjus (France/Italy), Pyhásalmi (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

The LAGUNA project: Towards the giant liquid based detectors for proton decay searches and for low energy neutrino astrophysics

A next generation European deep underground neutrino observatory is considered within the LAGUNA design study. Three detector options are presently considered: GLACIER liquid argon Time Projection Chamber; LENA liquid scintillator and MEMPHYS water Cherenkov. It will provide both: the high statistics measurement of neutrinos from variety of sources, and high sensitivity searches for matter instability. To accommodate such giant detectors a new underground laboratory is required. The LAGUNA design study considers the following seven candidate sites in Europe: Boulby (UK), Canfranc (Spain), Fréjus (France/Italy), Pyhäsalmi (Finland), Polkowice-Sieroszowice (Poland), Slanic (Romania) and Umbria (Italy). The three detection techniques and summary of the physics potential of proposed detectors are discussed in this short paper