399 research outputs found
Gas Chromatographic Studies of Oxide and Hydroxide Species of Tungsten - Model Experiments with Respect to the Physico-Chemical Characterization of Seaborgium (Element 106)
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Sandia`s network for Supercomputer `96: Linking supercomputers in a wide area Asynchronous Transfer Mode (ATM) network
The advanced networking department at Sandia National Laboratories has used the annual Supercomputing conference sponsored by the IEEE and ACM for the past several years as a forum to demonstrate and focus communication and networking developments. At Supercomputing 96, for the first time, Sandia National Laboratories, Los Alamos National Laboratory, and Lawrence Livermore National Laboratory combined their Supercomputing 96 activities within a single research booth under the ASO banner. Sandia provided the network design and coordinated the networking activities within the booth. At Supercomputing 96, Sandia elected: to demonstrate wide area network connected Massively Parallel Processors, to demonstrate the functionality and capability of Sandia`s new edge architecture, to demonstrate inter-continental collaboration tools, and to demonstrate ATM video capabilities. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations support Sandia`s overall strategies in ATM networking
Observation of muon intensity variations by season with the MINOS near detector
A sample of 1.53 x 10(9) cosmic-ray-induced single muon events has been recorded at 225 m water equivalent using the MINOS near detector. The underground muon rate is observed to be highly correlated with the effective atmospheric temperature. The coefficient alpha(T), relating the change in the muon rate to the change in the vertical effective temperature, is determined to be 0.428 +/- 0.003(stat.) +/- 0.059(syst.). An alternative description is provided by the weighted effective temperature, introduced to account for the differences in the temperature profile and muon flux as a function of zenith angle. Using the latter estimation of temperature, the coefficient is determined to be 0.352 +/- 0.003(stat.) +/- 0.046(syst.)
Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters
We present the results of a global neutrino oscillation data analysis within
the three-flavour framework. We include latest results from the MINOS
long-baseline experiment (including electron neutrino appearance as well as
anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK
I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent
re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These
results have important consequences for the analysis of reactor experiments and
in particular for the status of the mixing angle . In our
recommended default analysis we find from the global fit that the hint for
non-zero remains weak, at 1.8 for both neutrino mass
hierarchy schemes. However, we discuss in detail the dependence of these
results on assumptions concerning the reactor neutrino analysis.Comment: 15 pages, 10 figures and 2 tables, v2: corrected version, main
conclusions unchanged, references adde
Attenuation Length of light in the CHIPS-M Water Cherenkov Detector
The water at the proposed site of the CHIPS water Cherenkov detector has been studied to measure its attenuation length as a function of filtering time. A 3.2m vertical column was filled with the water from the Wentworth Pit, proposed site of the CHIPS deployment. Results consistent with attenuation lengths of up to 100m have been observed at this wavelength with filtration and UV sterilization alone
Measurement of the Atmospheric Muon Charge Ratio at TeV Energies with MINOS
The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray
muon data since the beginning of August, 2003 at a depth of 2070
meters-water-equivalent in the Soudan Underground Laboratory, Minnesota, USA.
The data with both forward and reversed magnetic field running configurations
were combined to minimize systematic errors in the determination of the
underground muon charge ratio. When averaged, two independent analyses find the
charge ratio underground to be 1.374 +/- 0.004 (stat.) +0.012 -0.010(sys.).
Using the map of the Soudan rock overburden, the muon momenta as measured
underground were projected to the corresponding values at the surface in the
energy range 1-7 TeV. Within this range of energies at the surface, the MINOS
data are consistent with the charge ratio being energy independent at the two
standard deviation level. When the MINOS results are compared with measurements
at lower energies, a clear rise in the charge ratio in the energy range 0.3 --
1.0 TeV is apparent. A qualitative model shows that the rise is consistent with
an increasing contribution of kaon decays to the muon charge ratio.Comment: 16 pages, 17 figure
Measurement of neutrino velocity with the MINOS detectors and NuMI neutrino beam
The velocity of a ~3 GeV neutrino beam is measured by comparing detection times at the near and far detectors of the MINOS experiment, separated by 734 km. A total of 473 far detector neutrino events was used to measure (v-c)/c=5.12.910-5 (at 68% C.L.). By correlating the measured energies of 258 charged-current neutrino events to their arrival times at the far detector, a limit is imposed on the neutrino mass of mnu<50 MeV/c2 (99% C.L.)
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First Direct Observation of Muon Antineutrino Disappearance
This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν̅ _μ production, accumulating an exposure of 1.71×10^(20) protons on target. In the Far Detector, 97 charged current ν̅ _μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm̅ 2|= [3.36=_(-0.40)^(+0.46)(stat)±0.06(syst)]x10^(-3)eV^2,sin^2(2θ̅)=0.86 _(-0.12)^(+0.11)(stat)±0.01(syst). The MINOS ν̅ _μ and ν̅ _μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters
Measurement of the Neutrino Mixing Angle theta(23) in NOvA
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05 x 10(20) protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal theta(23) mixing (theta(23) = pi/4). Assuming the normal mass hierarchy, we find Delta m(32)(2) = (2.67 +/- 0.11) x 10(-3) eV(2) and sin(2) theta(23)at the two statistically degenerate values 0.404(-0.022)(+0.030) and 0.624(-0.030)(+0.022), both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6 sigma significance
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