Development and Characterisation of a Gas System and its Associated Slow-Control System for an ATLAS Small-Strip Thin Gap Chamber Testing Facility

A quality assurance and performance qualification laboratory was built at McGill University for the Canadian-made small-strip Thin Gap Chamber (sTGC) muon detectors produced for the 2019-2020 ATLAS experiment muon spectrometer upgrade. The facility uses cosmic rays as a muon source to ionise the quenching gas mixture of pentane and carbon dioxide flowing through the sTGC detector. A gas system was developed and characterised for this purpose, with a simple and efficient gas condenser design utilizing a Peltier thermoelectric cooler (TEC). The gas system was tested to provide the desired 45 vol% pentane concentration. For continuous operations, a state-machine system was implemented with alerting and remote monitoring features to run all cosmic-ray data-acquisition associated slow-control systems, such as high/low voltage, gas system and environmental monitoring, in a safe and continuous mode, even in the absence of an operator.Comment: 23 pages, LaTeX, 14 figures, 4 tables, proof corrections for Journal of Instrumentation (JINST), including corrected Fig. 8b

Study of charged particle correlations and underlying events with the ATLAS detector

Recent ATLAS measurements of underlying event properties and charged particle angular correlations are reviewed. Measurements are done at centre-of-mass energies of 900~GeV and 7~TeV in the range $|eta|<$2.5. The results are compared to various Monte Carlo models and tunes

Studies of vector boson+jet production with the ATLAS detector

The production of jets or b-jets in association with a leptonically-decaying W or Z boson in proton-proton collisions at 7~TeV is an important test of quantum chromodynamics (QDC). Cross sections have been measured up to high jet multiplicities and compared to new higher-order QCD calculations. The ratio of (Z + a single jet)/(W + a single jet) has also been measured. Overall, the cross sections demonstrate the need for the inclusion of higher-multiplicity matrix elements in the calculations

Utility of Including Passive Neutron Albedo Reactivity in an Integrated NDA System for Encapsulation Safeguards

Abstract: In August of 2017, the International Atomic Energy Agency (IAEA) issued the “Application of Safeguards to Geological Repositories (ASTOR) Report on Technologies Potentially Useful for Safeguarding Geological Repositories.” In this IAEA report, the nuclear safeguards experts convened made recommendations on var ious aspects of encapsulation facility and repository safeguards. Specific to the non-destructive assay (NDA) requirements, the ASTOR experts made six specific recommendations. To satisfy these recommendations, a team working under the direction of the Finnish Radiation and Safety Authority researched the capability of an integrated NDA system that combines the capabilities of a Passive Gamma Emission Tomography (PGET) instrument, a Passive Neutron Albedo Reactivity (PNAR) instrument and a load cell. The current study focuses a conceptual design of the PNAR instrument capable of supporting several of the IAEA recommendations. To enable this research goal, the performance of a PNAR instrument, designed to measure boiling water reactor assemblies, was simulated using fuel with the isotopic content representative of fuel of various initial enrichments, burnups and cooling times. The research results illustrate the capability of the PNAR instrument to fulfil the IAEA recommendations while using robust, relatively simple, hardware

A model for presenting accelerometer paradata in large studies: ISCOLE

Background: We present a model for reporting accelerometer paradata (process-related data produced from survey administration) collected in the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE), a multi-national investigation of >7000 children (averaging 10.5 years of age) sampled from 12 different developed and developing countries and five continents. Methods: ISCOLE employed a 24-hr waist worn 7-day protocol using the ActiGraph GT3X+. Checklists, flow charts, and systematic data queries documented accelerometer paradata from enrollment to data collection and treatment. Paradata included counts of consented and eligible participants, accelerometers distributed for initial and additional monitoring (site specific decisions in the face of initial monitoring failure), inadequate data (e.g., lost/malfunction, insufficient wear time), and averages for waking wear time, valid days of data, participants with valid data (>4 valid days of data, including 1 weekend day), and minutes with implausibly high values (>20,000 activity counts/min). Results: Of 7806 consented participants, 7372 were deemed eligible to participate, 7314 accelerometers were distributed for initial monitoring and another 106 for additional monitoring. 414 accelerometer data files were inadequate (primarily due to insufficient wear time). Only 29 accelerometers were lost during the implementation of ISCOLE worldwide. The final locked data file consisted of 6553 participant files (90.0% relative to number of participants who completed monitoring) with valid waking wear time, averaging 6.5 valid days and 888.4 minutes/day (14.8 hours). We documented 4762 minutes with implausibly high activity count values from 695 unique participants (9.4% of eligible participants and <0.01% of all minutes). Conclusions: Detailed accelerometer paradata is useful for standardizing communication, facilitating study management, improving the representative qualities of surveys, tracking study endpoint attainment, comparing studies, and ultimately anticipating and controlling costs