25 research outputs found

    HNX/SuperTIGER Silicon Strip Detector Response to Nuclei in Lead Primary and Fragmented Test Beams

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    The response to 150 GeV/nuc primary lead (^(208)Pb) and fragmented (A/Z=2.4, 2.2, 2.0) beams measured a silicon strip detector, designed for use in the Heavy Nuclei eXplorer (HNX) and an upgrade of the Super Trans-Iron Galactic Element Recorder (SuperTIGER) balloon experiment, was evaluated in a CERN test beam (H8A) during Nov - Dec 2018. The 500 μm thick, single-sided silicon detectors have 32 DC-coupled strips with 3 mm pitch on the junction side with 9.6×9.6 cm^2 active area. Discrete charge-preamplifiers and shaping amplifiers were used to read out the ohmic and junction side signals simultaneously using the SuperTIGER DAQ system. We report on the response in a configuration where all 32 strips were joined and read out together. The strip detector-under-test was situated between planar silicon detectors, which provided the charge selection as well as a comparison of the measured response of each detector. The combined data set shows excellent charge resolution and finely resolved elemental peaks from helium (Z=2) through lead (Z=82). In this paper, we provide a description of the test beam experiment and the results of the charge resolution analysis

    Cosmic-Ray Positrons: Are There Primary Sources?

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    Cosmic rays at the Earth include a secondary component originating in collisions of primary particles with the diffuse interstellar gas. The secondary cosmic rays are relatively rare but carry important information on the Galactic propagation of the primary particles. The secondary component includes a small fraction of antimatter particles, positrons and antiprotons. In addition, positrons and antiprotons may also come from unusual sources and possibly provide insight into new physics. For instance, the annihilation of heavy supersymmetric dark matter particles within the Galactic halo could lead to positrons or antiprotons with distinctive energy signatures. With the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument, we have measured the abundances of positrons and electrons at energies between 1 and 50 GeV. The data suggest that indeed a small additional antimatter component may be present that cannot be explained by a purely secondary production mechanism. Here we describe the signature of the effect and discuss its possible origin.Comment: 15 pages, Latex, epsfig and aasms4 macros required, to appear in Astroparticle Physics (1999

    HNX/SuperTIGER Silicon Strip Detector Response to Nuclei in Lead Primary and Fragmented Test Beams

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    The response to 150 GeV/nuc primary lead (^(208)Pb) and fragmented (A/Z=2.4, 2.2, 2.0) beams measured a silicon strip detector, designed for use in the Heavy Nuclei eXplorer (HNX) and an upgrade of the Super Trans-Iron Galactic Element Recorder (SuperTIGER) balloon experiment, was evaluated in a CERN test beam (H8A) during Nov - Dec 2018. The 500 μm thick, single-sided silicon detectors have 32 DC-coupled strips with 3 mm pitch on the junction side with 9.6×9.6 cm^2 active area. Discrete charge-preamplifiers and shaping amplifiers were used to read out the ohmic and junction side signals simultaneously using the SuperTIGER DAQ system. We report on the response in a configuration where all 32 strips were joined and read out together. The strip detector-under-test was situated between planar silicon detectors, which provided the charge selection as well as a comparison of the measured response of each detector. The combined data set shows excellent charge resolution and finely resolved elemental peaks from helium (Z=2) through lead (Z=82). In this paper, we provide a description of the test beam experiment and the results of the charge resolution analysis

    The OASIS Mission

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    The Orbiting Astrophysical Observatory in Space (OASIS) is a mission to investigate Galactic Cosmic Rays (GCRs), a major feature of our galaxy. OASIS will use measurements of GCRs to determine the cosmic ray source, where they are accelerated, to investigate local accelerators and to learn what they can tell us about the interstellar medium and the processes that occur in it. OASIS will determine the astrophysical sources of both the material and acceleration of GCRs by measuring the abundances of the rare actinide nuclei and make direct measurements of the spectrum and anisotropy of electrons at energies up to approx.10 TeV, well beyond the range of the Fermi and AMS missions. OASIS has two instruments. The Energetic Trans-Iron Composition Experiment (ENTICE) instrument measures elemental composition. It resolves individual elements with atomic number (Z) from 10 to 130 and has a collecting power of 60m2.str.yrs, >20 times larger than previous instruments, and with improved resolution. The sample of 10(exp 10) GCRs collected by ENTICE will include .100 well-resolved actinides. The High Energy Particle Calorimeter Telescope (HEPCaT) is an ionization calorimeter that will extend the electron spectrum into the TeV region for the first time. It has 7.5 sq m.str.yrs of collecting power. This talk will describe the scientific objectives of the OASIS mission and its discovery potential. The mission and its two instruments which have been designed to accomplish this investigation will also be described

    Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

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    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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