4,800 research outputs found
Recent Results from the MINOS experiment
MINOS is an accelerator neutrino oscillation experiment at Fermilab. An
intense high energy neutrino beam is produced at Fermilab and sent to a near
detector on the Fermilab site and also to a 5 kTon far detector 735 km away in
the Soudan mine in northern Minnesota. The experiment has now had several years
of running with millions of events in the near detector and hundreds of events
recorded in the far detector. I will report on the recent results from this
experiment which include precise measurement of , ~analysis
of neutral current data to limit the component of sterile neutrinos, and the
search for conversion. The focus will be on the analysis of
data for conversion. Using data from an exposure of
protons on target, we have selected electron type events
in both the near and the far detector. The near detector is used to measure the
background which is extrapolated to the far detector. We have found 35 events
in the signal region with a background expectation of . Using this observation we set a 90% C.L. limit of for and normal mass hierarchy. Further
analysis is under way to reduce backgrounds and improve sensitivity.Comment: This was prepared for the proceedings of the XIII International
Workshop on Neutrino Telescopes at the Istituto Veneto di Scienze, Lettere ed
Arti in Venice, Italy held on March 10-13, 2009. The presentation was on
behalf of the MINOS collaboratio
Very Long Baseline Neutrino Oscillations, The BNL VLBNLO Concept
A wide energy-band neutrino beam sent over a very long baseline to a massive
detector can break the degeneracies in the neutrino oscillation parameters. It
can measure the disappearance parameters with precision and determine the mass
hierarchy. If is large enough the CP violating phase can be
measured with neutrino running alone and anti-neutrino running can confirm CPV
and improve the parameter measurements. Brookhaven National Laboratory is
pursuing such an experiment.Comment: 3 pages, 3 figures, espcrc2.sty. To be published in the proceedings
of NuFact0
A study of hydrogen environment effects on microstructure property behavior of NASA-23 alloy and related alloy systems
This work is part of the overall advanced main combustion chamber (AMCC) casting characterization program of the Materials and Processes Laboratory of the Marshall Space Flight Center. The influence of hydrogen on the tensile properties and ductility behavior of NASA-23 alloy were analyzed. NASA-23 and other referenced alloys in cast and hipped conditions were solution treated and aged under selected conditions and characterized using optical metallography, scanning electron microscopy, and electron microprobe analysis techniques. The yield strength of NASA-23 is not affected much by hydrogen under tensile tests carried at 5000 psig conditions; however, the ultimate strength and ductility properties are degraded. This implies that the physical mechanisms operating would be related to the plastic deformation process. The fracture surfaces characteristics of NASA-23 specimens tensile tested in hydrogen, helium, and air were also analyzed. These revealed surface cracks around specimen periphery with the fracture surface showing a combination of intergranular and transgranular modes of fracture. It is seen that the specimens charged in hydrogen seem to favor a more brittle fracture mode in comparison to air and helium charged specimens. The AMCC casting characterization program is to be analyzed for their hydrogen behavior. As a result of this program, the basic microstructural factors and fracture characteristics in some cases were analyzed
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