How to calculate dark matter direct detection exclusion limits that are consistent with gamma rays from annihilation in the Milky Way halo

When comparing constraints on the weakly interacting massive particle (WIMP) properties from direct and indirect detection experiments it is crucial that the assumptions made about the dark matter (DM) distribution are realistic and consistent. For instance, if the Fermi-LAT Galactic center GeV gamma-ray excess was due to WIMP annihilation, its morphology would be incompatible with the standard halo model that is usually used to interpret data from direct detection experiments. In this article, we calculate exclusion limits from direct detection experiments using self-consistent velocity distributions, derived from mass models of the Milky Way where the DM halo has a generalized Navarro-Frenk-White profile. We use two different methods to make the mass model compatible with a DM interpretation of the Galactic center gamma-ray excess. First, we fix the inner slope of the DM density profile to the value that best fits the morphology of the excess. Second, we allow the inner slope to vary and include the morphology of the excess in the data sets used to constrain the gravitational potential of the Milky Way. The resulting direct detection limits differ significantly from those derived using the standard halo model, in particular for light WIMPs, due to the differences in both the local DM density and velocity distribution

TREX-DM: a low background Micromegas-based TPC for low-mass WIMP detection

Dark Matter experiments are recently focusing their detection techniques in low-mass WIMPs, which requires the use of light elements and low energy threshold. In this context, we describe the TREX-DM experiment, a low background Micromegas-based TPC for low-mass WIMP detection. Its main goal is the operation of an active detection mass $\sim$0.3 kg, with an energy threshold below 0.4 keVee and fully built with previously selected radiopure materials. This work describes the commissioning of the actual setup situated in a laboratory on surface and the updates needed for a possible physics run at the Canfranc Underground Laboratory (LSC) in 2016. A preliminary background model of TREX-DM is also presented, based on a Geant4 simulation, the simulation of the detector's response and two discrimination methods: a conservative muon/electron and one based on a neutron source. Based on this background model, TREX-DM could be competitive in the search for low-mass WIMPs. In particular it could be sensitive, e.g., to the low-mass WIMP interpretation of the DAMA/LIBRA and other hints in a conservative scenario.Comment: Proceedings of the XIV International Conference on Topics in Astroparticle and Underground Physics (TAUP 2015), 7-11 September 2015, Torino, Ital

Production of Low-Carbon Magnetic Steel for the LHC Superconducting Dipole and Quadrupole Magnets

In 1996 CERN negotiated a contract with Cockerill Sambre â ARCELOR Group for the supply of 50 000 tonnes of low-carbon steel for the LHC main magnets: this was the first contract to be placed for the project, and one of the single largest. In 2005 â after nine years of work â the contract is being successfully completed. This paper describes the steel specifically developed, known as MAGNETILâ¢, its manufacturing and quality control process, organization of production, logistics and contract follow-up. Extensive statistics have been collected relating to physical, mechanical and technological parameters. Specific attention is dedicated to magnetic measurements (coercivity and permeability) performed at both room and cryogenic temperatures, the equipment used and statistical results. Reference is also made to the resulting precision of the fineblanked laminations used for the magnet yoke. The technology transfer from the particle accelerator domain to industry is ongoing, for example for the screening of high voltage cables buried in the ground

Towards the production of 50'000 tonnes of low-carbon steel sheet for the LHC superconducting dipole and quadrupole magnets

A total of 50'000 tonnes of low-carbon steel sheet has been ordered for the LHC main magnets. After three years of production, about 10'000 tonnes of steel sheet have been produced by Cockerill-Sambre Groupe Usinor. This paper gives a summary of the manufacturing process and improvements implemented as well as an overview of the difficulties encountered during this production. Preliminary statistics obtained for the mechanical and magnetic steel properties are presented

TREX-DM: a low background Micromegas-based TPC for low mass WIMP detection

Dark Matter experiments are recently focusing their detection techniques in low-mass WIMPs, which requires the use of light elements and low energy threshold. In this context, we present the TREX-DM experiment, a low background Micromegas-based TPC for low-mass WIMP detection. Its main goal is the operation of an active detection mass $\sim$0.300 kg, with an energy threshold below 0.4 keVee and fully built with previously selected radiopure materials. This article describes the actual setup, the first results of the comissioning in Ar+2\%iC$_4$H$_{10}$ at 1.2 bar and the future updates for a possible physics run at the Canfranc Underground Laboratory in 2016. A first background model is also presented, based on Geant4 simulations and a muon/electron discrimination method. In a conservative scenario, TREX-DM could be sensitive to DAMA/LIBRA and other hints of positive WIMPs signals, with some space for improvement with a neutron/electron discrimination method or the use of other light gases.Comment: Proceedings of the 7th Symposium on Large TPCs for Low-Energy Rare Event Detectio

Sensitivity of BWR stability calculations to numerical integration techniques

Computer simulations have shown that stability calculations in boiling water reactors (BWRs) are very sensitive to a number of input parameters, modeling assumptions, and numerical integration techniques. Following the 1988 LaSalle instability event, a significant industry-wide effort was invested in identifying these sensitivities. One major conclusion from these studies was that existing time-domain codes could best predict BWR stability by using explicit methods for the energy equation with a Courant number as close to unity as possible. This paper presents a series of sensitivity studies using simplified models, which allow us to determine the effect that different numerical integration techniques have on the results of stability calculations. The present study appears to indicate that, even though using explicit integration with a Courant number of one is adequate for existing codes using time-integration steps of less than 10 ms, second-order solution techniques for the time integration can result in significant improvements in the accuracy of linear (i.e., decay ratio) stability calculations

Altered Metabolic Profile in Congenital Lung Lesions Revealed by1H Nuclear Magnetic Resonance Spectroscopy

Congenital lung lesions are highly complex with respect to pathogenesis and treatment. Large-scale analytical methods, like metabolomics, are now available to identify biomarkers of pathological phenotypes and to facilitate clinical management. Nuclear magnetic resonance (NMR) is a unique tool for translational research, as in vitro results can be potentially translated into in vivo magnetic resonance protocols. Three surgical biopsies, from congenital lung malformations, were analyzed in comparison with one control sample. Extracted hydrophilic metabolites were submitted to high resolution 1H NMR spectroscopy and the relative concentration of 12 metabolites was estimated. In addition, two-dimensional NMR measurements were performed to complement the results obtained from standard monodimensional experiments. This is one of the first reports of in vitro metabolic profiling of congenital lung malformation. Preliminary data on a small set of samples highlights some altered metabolic ratios, dealing with the glucose conversion to lactate, to the relative concentration of phosphatidylcholine precursors, and to the presence of myoinositol. Interestingly some relations between congenital lung lesions and cancer metabolic alterations are found

Advancing in the analysis of materials in electr(on)ic equipment

Despite there is a great effort to support strategies for a circular economy of electr(on)ics as maintenance, repair, remanufacture and reuse, recycling keeps being the final ultimate stage reached by them. As the supply of materials has become a key issue for the economic and technology development, more information about the content of materials in electr(on)ics is in order. This is especially for printed circuit boards contained in the majority of electr(on)ics which have a great variety of materials with a significant economic value. This paper discusses two methodologies to quantify the material composition of these parts. The first methodology quantifies the material content using two algorithms to identify the typologies of electr(on)ics components, and the average material composition of some typologies of electr(on)ic components given by original manufacturers. The second methodology uses the Database of SEmiconductors (DoSE) which contains the full material composition of about 250 different electr(on)ic components of printed circuit boards. A case study based on the analysis of two models of battery management systems contained in the batteries of electric vehicles is developed to compare the material composition results obtained from the two methodologies. Although the analysis is limited to some electr(on)ic components, mainly the integrated circuit and capacitors, the results of the composition of the battery management system are given for a list of materials including aluminum, copper, iron, gold, lead, nickel and tantalum. For two of the most economically relevant materials, copper and gold, the results obtained by the two methodologies differ 2% for copper and 4% for gold. To advance towards more automatized and systematic methodologies to estimate the material composition of the battery management systems, there are some further developments needed: to increase datasets for other electr(on)ic components as connectors, and better quantification of the number of layers and finishing of the circuit boards as they are made of significant quantities of copper and gold

A Novel Device for the Measurement of the Mechanical and Magnetic Axes of Superconducting Magnet Assemblies for Accelerators

In the context of the LHC superconducting magnet production, especially for dipoles and quadrupoles due to their complexity, it is foreseen to perform acceptance tests, at an early production stage, to detect possible significant deviations from the design values. The knowledge of the magnetic field geometry is very important, especially for the main magnets. In order to get this information a new device has been conceived that measures the magnets at room temperature during different stages of construction. This device incorporates a sensitive measuring probe and an efficient data acquisition system because the coils are only powered at about 10-5 of the nominal D.C. current. It is dedicated to Quadrupole and Dipole (by using Quadrupole-Configured Dipole (QCD) transformation) magnets, but is also easily adaptable to higher order magnets (n = 3, 4 and 5) by specific orientation of the search coils. It is equipped with magnetic sensors (4 fixed tangential coils and AC excitation current for the magnet) and position sensors (3D-laser tracker and light reflector) that allow the simultaneous detection of the magnetic field axis and the cold bore axis. It is equipped as well with a set of 4 LEDs and associated with a CCD camera that allows both the measurement of the cold bore diameter and its position with respect to the mole. This paper describes the system and reports the first results measured on the pre-series magnets recently assembled