1,250 research outputs found

    Testing of High Voltage Surge Protection Devices for Use in Liquid Argon TPC Detectors

    Get PDF
    In this paper we demonstrate the capability of high voltage varistors and gas discharge tube arrestors for use as surge protection devices in liquid argon time projection chamber detectors. The insulating and clamping behavior of each type of device is characterized in air (room temperature), and liquid argon (90~K), and their robustness under high voltage and high energy surges in cryogenic conditions is verified. The protection of vulnerable components in liquid argon during a 150 kV high voltage discharge is also demonstrated. Each device is tested for argon contamination and light emission effects, and both are constrained to levels where no significant impact upon liquid argon time projection chamber functionality is expected. Both devices investigated are shown to be suitable for HV surge protection applications in cryogenic detectors.Comment: 22 pages, 18 figures v2: reduced file size for journal submissio

    A Membership Retention Strategy For The Maranatha Seventh-day Adventist Church

    Get PDF
    Problem For the past three decades, pastors and lay leaders of the Maranatha Seventh-day Adventist Church, situated in the city of Miami Gardens, Florida, USA, have fostered the longing for a comprehensive discipleship strategy that is geared toward new member retention. Although church leaders have attempted to address the problem of attrition, due to the lack of effective discipleship, by hiring full time Bible workers, forming new member classes, and creating ministry opportunities, a sustainable, competency-driven, and user-friendly curriculum did not emerge. Due to a combined growth rate of 29. 4% in membership, between the years 2002-2012, a comprehensive discipleship curriculum was considered to be of missional urgency. Method A discipleship curriculum, with emphasis on new member care and retention, was developed and implemented between 2012 and 2014. Its purpose was to educate, equip, and engage church leaders in a series of training seminars that would link theory to practice. This discipleship curriculum emphasized the learning components of mentoring connections, spiritual formation, and membership accountability. It was instructional in the competencies of spiritual disciplines, transformational relationships, personal stewardship, biblical discipleship, spiritual giftedness, and sensitivity to missing members. While the curriculum was based on the above-mentioned competencies, its effectiveness was measured in terms of participation level, overall commitment, changes in practice of church leaders toward their new converts, and the level of increase in membership enlightenment. Results Once a discipleship curriculum for training church leaders and members was developed, based on the six main competencies that emerged from the new member’s surveys, a series of training seminars was conducted. Although the training was first designed and promoted for church leaders, church leadership requested the participation of all church members. Consequently, 60% of active church members attended and completed the requirements of the program. This included 100% of pastoral staff, 80% of church officers, 30% of church youth and pathfinder leaders, and 65 regular church members. A further 180 new members responded to the new member surveys. Generally, seminar participants commenced with much curiosity and an eagerness to learn. However, over 90% of participants reported that they were enlightened and better equipped to engage in the discipleship process of the church. There were two curriculum weaknesses: namely, a shortage of new members to be placed in mentoring relationships with seasoned members and insufficient time for implementing the curriculum. Conclusions Three important learnings emerged from this study. First, church leaders are eager to become more efficient in member discipleship. Second, a well-developed, competency-based, and easy to-follow discipleship curriculum is crucial to membership retention in the Seventh-day Adventist Church. Third, it will require more transformational relationships than curriculum theory to retain members in the church. This research revealed that a curriculum of this sort is of missional urgency. It is crucial in the struggle to retain and disciple the people that God brings (Acts 2:27, 28) to the church

    Mass hierarchy, 2-3 mixing and CP-phase with Huge Atmospheric Neutrino Detectors

    Full text link
    We explore the physics potential of multi-megaton scale ice or water Cherenkov detectors with low (1\sim 1 GeV) threshold. Using some proposed characteristics of the PINGU detector setup we compute the distributions of events versus neutrino energy EνE_\nu and zenith angle θz\theta_z, and study their dependence on yet unknown neutrino parameters. The (Eνθz)(E_\nu - \theta_z) regions are identified where the distributions have the highest sensitivity to the neutrino mass hierarchy, to the deviation of the 2-3 mixing from the maximal one and to the CP-phase. We evaluate significance of the measurements of the neutrino parameters and explore dependence of this significance on the accuracy of reconstruction of the neutrino energy and direction. The effect of degeneracy of the parameters on the sensitivities is also discussed. We estimate the characteristics of future detectors (energy and angle resolution, volume, etc.) required for establishing the neutrino mass hierarchy with high confidence level. We find that the hierarchy can be identified at 3σ3\sigma -- 10σ10\sigma level (depending on the reconstruction accuracies) after 5 years of PINGU operation.Comment: 39 pages, 21 figures. Description of Fig.3 correcte

    Determination of muon momentum in the MicroBooNE LArTPC using an improved model of multiple Coulomb scattering

    Full text link
    We discuss a technique for measuring a charged particle's momentum by means of multiple Coulomb scattering (MCS) in the MicroBooNE liquid argon time projection chamber (LArTPC). This method does not require the full particle ionization track to be contained inside of the detector volume as other track momentum reconstruction methods do (range-based momentum reconstruction and calorimetric momentum reconstruction). We motivate use of this technique, describe a tuning of the underlying phenomenological formula, quantify its performance on fully contained beam-neutrino-induced muon tracks both in simulation and in data, and quantify its performance on exiting muon tracks in simulation. Using simulation, we have shown that the standard Highland formula should be re-tuned specifically for scattering in liquid argon, which significantly improves the bias and resolution of the momentum measurement. With the tuned formula, we find agreement between data and simulation for contained tracks, with a small bias in the momentum reconstruction and with resolutions that vary as a function of track length, improving from about 10% for the shortest (one meter long) tracks to 5% for longer (several meter) tracks. For simulated exiting muons with at least one meter of track contained, we find a similarly small bias, and a resolution which is less than 15% for muons with momentum below 2 GeV/c. Above 2 GeV/c, results are given as a first estimate of the MCS momentum measurement capabilities of MicroBooNE for high momentum exiting tracks

    Noise Characterization and Filtering in the MicroBooNE Liquid Argon TPC

    Full text link
    The low-noise operation of readout electronics in a liquid argon time projection chamber (LArTPC) is critical to properly extract the distribution of ionization charge deposited on the wire planes of the TPC, especially for the induction planes. This paper describes the characteristics and mitigation of the observed noise in the MicroBooNE detector. The MicroBooNE's single-phase LArTPC comprises two induction planes and one collection sense wire plane with a total of 8256 wires. Current induced on each TPC wire is amplified and shaped by custom low-power, low-noise ASICs immersed in the liquid argon. The digitization of the signal waveform occurs outside the cryostat. Using data from the first year of MicroBooNE operations, several excess noise sources in the TPC were identified and mitigated. The residual equivalent noise charge (ENC) after noise filtering varies with wire length and is found to be below 400 electrons for the longest wires (4.7 m). The response is consistent with the cold electronics design expectations and is found to be stable with time and uniform over the functioning channels. This noise level is significantly lower than previous experiments utilizing warm front-end electronics.Comment: 36 pages, 20 figure

    Ionization Electron Signal Processing in Single Phase LArTPCs II. Data/Simulation Comparison and Performance in MicroBooNE

    Full text link
    The single-phase liquid argon time projection chamber (LArTPC) provides a large amount of detailed information in the form of fine-grained drifted ionization charge from particle traces. To fully utilize this information, the deposited charge must be accurately extracted from the raw digitized waveforms via a robust signal processing chain. Enabled by the ultra-low noise levels associated with cryogenic electronics in the MicroBooNE detector, the precise extraction of ionization charge from the induction wire planes in a single-phase LArTPC is qualitatively demonstrated on MicroBooNE data with event display images, and quantitatively demonstrated via waveform-level and track-level metrics. Improved performance of induction plane calorimetry is demonstrated through the agreement of extracted ionization charge measurements across different wire planes for various event topologies. In addition to the comprehensive waveform-level comparison of data and simulation, a calibration of the cryogenic electronics response is presented and solutions to various MicroBooNE-specific TPC issues are discussed. This work presents an important improvement in LArTPC signal processing, the foundation of reconstruction and therefore physics analyses in MicroBooNE.Comment: 54 pages, 36 figures; the first part of this work can be found at arXiv:1802.0870

    Yoga jam: remixing Kirtan in the Art of Living

    Get PDF
    Yoga Jam are a group of musicians in the United Kingdom who are active members of the Art of Living, a transnational Hindu-derived meditation group. Yoga Jam organize events—also referred to as yoga raves and yoga remixes—that combine Hindu devotional songs (bhajans) and chants (mantras) with modern Western popular musical genres, such as soul, rock, and particularly electronic dance music. This hybrid music is often played in a clublike setting, and dancing is interspersed with yoga and meditation. Yoga jams are creative fusions of what at first sight seem to be two incompatible phenomena—modern electronic dance music culture and ancient yogic traditions. However, yoga jams make sense if the Durkheimian distinction between the sacred and the profane is challenged, and if tradition and modernity are not understood as existing in a sort of inverse relationship. This paper argues that yoga raves are authenticated through the somatic experience of the modern popular cultural phenomenon of clubbing combined with therapeutic yoga practices and validated by identifying this experience with a reimagined Vedic tradition

    Design and construction of the MicroBooNE Cosmic Ray Tagger system

    Get PDF
    The MicroBooNE detector utilizes a liquid argon time projection chamber (LArTPC) with an 85 t active mass to study neutrino interactions along the Booster Neutrino Beam (BNB) at Fermilab. With a deployment location near ground level, the detector records many cosmic muon tracks in each beam-related detector trigger that can be misidentified as signals of interest. To reduce these cosmogenic backgrounds, we have designed and constructed a TPC-external Cosmic Ray Tagger (CRT). This sub-system was developed by the Laboratory for High Energy Physics (LHEP), Albert Einstein center for fundamental physics, University of Bern. The system utilizes plastic scintillation modules to provide precise time and position information for TPC-traversing particles. Successful matching of TPC tracks and CRT data will allow us to reduce cosmogenic background and better characterize the light collection system and LArTPC data using cosmic muons. In this paper we describe the design and installation of the MicroBooNE CRT system and provide an overview of a series of tests done to verify the proper operation of the system and its components during installation, commissioning, and physics data-taking

    A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam

    Get PDF
    A Short-Baseline Neutrino (SBN) physics program of three LAr-TPC detectors located along the Booster Neutrino Beam (BNB) at Fermilab is presented. This new SBN Program will deliver a rich and compelling physics opportunity, including the ability to resolve a class of experimental anomalies in neutrino physics and to perform the most sensitive search to date for sterile neutrinos at the eV mass-scale through both appearance and disappearance oscillation channels. Using data sets of 6.6e20 protons on target (P.O.T.) in the LAr1-ND and ICARUS T600 detectors plus 13.2e20 P.O.T. in the MicroBooNE detector, we estimate that a search for muon neutrino to electron neutrino appearance can be performed with ~5 sigma sensitivity for the LSND allowed (99% C.L.) parameter region. In this proposal for the SBN Program, we describe the physics analysis, the conceptual design of the LAr1-ND detector, the design and refurbishment of the T600 detector, the necessary infrastructure required to execute the program, and a possible reconfiguration of the BNB target and horn system to improve its performance for oscillation searches.Comment: 209 pages, 129 figure
    corecore