255 research outputs found

    D0 Silicon Upgrade: Thermal Conductivity Measurements of Adhesives and Metal Strips

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    This note is a followup to previous work done relating to thermal conductivity tests for the DO Silicon Upgrade. The testing of adhesives described here was done as outlined in the above mentioned note; therefore, the experimental setup and design for testing adhesives is marginally described here. However, some strips were tested to determine their thermal conductivity which utilized a different testing setup. That setup is described here as well. The measured thermal conductivities of the adhesives show Ablefilm 563K to have the highest thermal conductivity value of 0.89 W/m-K. The strip tests also showed that a consistent thermal conductivity value can be obtained for a strip within 5%

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

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    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

    Muon-Induced Background Study for an Argon-Based Long Baseline Neutrino Experiment

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    We evaluated rates of transversing muons, muon-induced fast neutrons, and production of 40^{40}Cl and other cosmogenically produced nuclei that pose as potential sources of background to the physics program proposed for an argon-based long baseline neutrino experiment at the Sanford Underground Research Facility (SURF). The Geant4 simulations were carried out with muons and muon-induced neutrons for both 800 ft (0.712 km.w.e.) and 4850 ft levels (4.3 km.w.e.). We developed analytic models to independently calculate the 40^{40}Cl production using the measured muon fluxes at different levels of the Homestake mine. The muon induced 40^{40}Cl production rates through stopped muon capture and the muon-induced neutrons and protons via (n,p) and (p,n) reactions were evaluated. We find that the Monte Carlo simulated production rates of 40^{40}Cl agree well with the predictions from analytic models. A depth-dependent parametrization was developed and benchmarked to the direct analytic models. We conclude that the muon-induced processes will result in large backgrounds to the physics proposed for an argon-based long baseline neutrino experiment at a depth of less than 4.0 km.w.e.Comment: 12 pages, 15 figure

    Hydrostatic Level Sensors as High Precision Ground Motion Instrumentation for Tevatron and Other Energy Frontier Accelerators

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    Particle accelerators pushed the limits of our knowledge in search of the answers to most fundamental questions about micro-world and our Universe. In these pursuits, accelerators progressed to higher and higher energies and particle beam intensities as well as increasingly smaller and smaller beam sizes. As the result, modern existing and planned energy frontier accelerators demand very tight tolerances on alignment and stability of their elements: magnets, accelerating cavities, vacuum chambers, etc. In this article we describe the instruments developed for and used in such accelerators as Fermilab's Tevatron (FNAL, Batavia, IL USA) and for the studies toward an International Linear Collider (ILC). The instrumentation includes Hydrostatic Level Sensors (HLS) for very low frequency measurements. We present design features of the sensors, outline their technical parameters, describe test and calibration procedures and discuss different regimes of operation. Experimental results of the ground motion measurements with these detectors will be presented in subsequent paper
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