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  1. This paper reports on research that is part of a broader National Science Foundation (NSF)-funded, Innovations in Graduate Education (IGE) project. The project aims to enhance the research culture and broaden the participation in research of underrepresented groups within graduate engineering programs at a mid-sized historically black college or university. The project includes three initiatives that seek to assist in the development of a “research engineer identity” among the graduate students pursuing research-based degrees in the college. One of the three initiatives of the project, and focus of this paper, involves the development of a survey-based Research Engineer Identity Scale (REIS). A two stage sequential mixed-method research design is being used to develop the scale. This paper focuses on the first stage in the design which involved conducting focus groups with research engineers to gain insight into the content, character, and complications associated with internalizing a Research Engineer Identity (REI) in general and among people from underrepresented groups in particular. We report on four semi-structured focus groups that each lasted approximately 90 minutes in Fall 2019. Each focus group included about 6 to 9 faculty members, industry professionals, or graduate students who actively engaged in engineering research in the Southeastern United States. Focus group participants represented various academic disciplines within engineering as well as a range of demographic characteristics such as sex, race, ethnicity, and citizenship status. The focus group conversations were transcribed and transcriptions were entered into NVivo for coding and analysis. Inter-rater reliability procedures were used to ensure consistency of coding. This paper reports on the themes that emerged within the focus group discussions regarding what it means to “be a research engineer.” The findings describe similarities and differences across demographic characteristics in regard to the content, character, and complications associated with efforts to develop a Research Engineer Identity. The paper concludes by briefly describing the process that will be used to transform the emergent themes into pool of items to be included in a web-based questionnaire designed to measure Research Engineer Identity. 
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  2. Abstract The EXO-200 experiment searched for neutrinoless double-beta decay of 136 Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. This paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector. 
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  3. The ratio of the electric to magnetic form factors of the proton, μpGEp/GMp, has been measured for elastic electron-proton scattering with polarized beam and target up to four-momentum transfer squared Q2=5.66(GeV/c)2 using double spin asymmetry for target spin orientation aligned nearly perpendicular to the beam momentum direction. This measurement of μpGEp/GMp agrees with the Q2 dependence of previous recoil polarization data and reconfirms the discrepancy at high Q2 between the Rosenbluth and the polarization-transfer method with a different measurement technique and systematic uncertainties uncorrelated to those of the recoil-polarization measurements. The form factor ratio at Q2=2.06(GeV/c)2 has been measured as μpGEp/GMp=0.720±0.176stat±0.039sys, which is in agreement with an earlier measurement using the polarized target technique at similar kinematics. The form factor ratio at Q2=5.66(GeV/c)2 has been determined as μpGEp/GMp=0.244±0.353stat±0.013sys, which represents the highest Q2 measurement reached using double spin asymmetries with polarized target to date. 
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  4. Abstract The Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/ c charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1 $$\pm 0.6$$ ± 0.6 % and 84.1 $$\pm 0.6$$ ± 0.6 %, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation. 
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    Free, publicly-accessible full text available July 1, 2024
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