A search for short-lived neutral particles which decay to electron-positron pairs has been carried out using a beam of 275-GeV electrons incident on an instrumented tungsten beam dump. The experiment was sensitive to particles up to 10 MeV/c 2 in mass and down to 4x 10" l6 sec in lifetime.

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Conductive ceramic thin film thermocouples were investigated for application to silicon carbide fiber reinforced silicon carbide ceramic matrix composite (SiC/SiC CMC) components. High temperature conductive oxides based on indium and zinc oxides were selected for testing to high temperatures in air. Sample oxide films were first sputtered-deposited on alumina substrates then on SiC/SiC CMC sample disks. Operational issues such as cold junction compensation to a 0°C reference, resistivity and thermopower variations are discussed. Results show that zinc oxides have an extremely high resistance and thus increased complexity for use as a thermocouple, but thermocouples using indium oxides can achieve a strong, nearly linear response to high temperatures.Published by Elsevier B.V.

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The status of work at NASA Glenn Research Center to develop a minimally intrusive integrated sensor to provide real-time measurement of strain, heat flux and flow in high temperature

As a demonstration of technology maturation, a thin-film temperature sensor probe was fabricated and installed on a F117 turbofan engine via a borescope access port to monitor the temperature experienced in the bleed air passage of the compressor area during an engine checkout test run. To withstand the harsh conditions experienced in this environment, the sensor probe was built from high temperature materials. The thin-film thermocouple sensing elements were deposited by physical vapor deposition using pure metal elements, thus avoiding the inconsistencies of sputter-depositing particular percentages of materials to form standardized alloys commonly found in thermocouples. The sensor probe and assembly were subjected to a strict protocol of multi-axis vibrational testing as well as elevated temperature pressure testing to be qualified for this application. The thin-film thermocouple probe demonstrated a faster response than a traditional embedded thermocouple during the engine checkout run. Nomenclature α = thermal diffusivity (mm²·s -1 ) Au-Pt = gold vs. platinum (as a thermocouple) CTE = coefficient of thermal expansion (µm/m·K) dt = time step (s) Δt = time increment (numerical modeling) Δx = distance increment (numerical modeling) EHM = Engine Health Management (system) FFT = fast Fourier transform (analysis algorithm) GRC = Glenn Research Center (in Cleveland, Ohio) j, n = node, step indices (numerical modeling) τ = thermal time constant, of a thermocouple (s) T(t) = thermocouple reading (°C) T g (t) = gas temperature (°C) Ṫ = rate of heating, dT/dt, of a thermocouple (°C/s) VIPR = Vehicle Integrated Propulsion Research (project)

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