967 research outputs found

    Cotton Famine Relief Ligislation: A Study in Mid-Victorian Attitudes

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    The purpose of this thesis is to explain the cotton famine and resulting relief legislation as an example of attitudes characteristic of the mid-Victorian period. It is at times easier to understand a period of history by investigating a specific, readily defined event through the primary and secondary source material available and to interpret that period in terms of the forces involved in shaping the event. This reasoning is only valid, however, if the event is truly representative of the thought and behavior of the period. In my estimation the cotton famine was indeed representative, and it will be my task to demonstrate that parliamentary action was a clear example of the legislative application of the ideals of an age. The procedure will be to examine industrial conditions, especially in the cotton industry, and to record the events of the famine itself. Mid-Victorian attitudes in general will be discussed, and arguments offered by members of Parliament for and against cotton famine relief legislation will be explained in the light of prevailing social, political, and economic theories and attitudes

    Improved limits on nuebar emission from mu+ decay

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    We investigated mu+ decays at rest produced at the ISIS beam stop target. Lepton flavor (LF) conservation has been tested by searching for \nueb via the detection reaction p(\nueb,e+)n. No \nueb signal from LF violating mu+ decays was identified. We extract upper limits of the branching ratio for the LF violating decay mu+ -> e+ \nueb \nu compared to the Standard Model (SM) mu+ -> e+ nue numub decay: BR < 0.9(1.7)x10^{-3} (90%CL) depending on the spectral distribution of \nueb characterized by the Michel parameter rho=0.75 (0.0). These results improve earlier limits by one order of magnitude and restrict extensions of the SM in which \nueb emission from mu+ decay is allowed with considerable strength. The decay \mupdeb as source for the \nueb signal observed in the LSND experiment can be excluded.Comment: 10 pages, including 1 figure, 1 tabl

    Forward Beam Monitor for the KATRIN experiment

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    The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to measure the neutrino mass with a sensitivity of 0.2 eV (90 % CL). This will be achieved by a precision measurement of the endpoint region of the β-electron spectrum of tritium decay. The β-electrons are produced in the Windowless Gaseous Tritium Source (WGTS) and guided magnetically through the beamline. In order to accurately extract the neutrino mass the source activity is required to be stable and known to a high precision. The WGTS therefore undergoes constant extensive monitoring from several measurement systems. The Forward Beam Monitor (FBM) is one such monitoring system. The FBM system comprises a complex mechanical setup capable of inserting a detector board into the KATRIN beamline with a positioning precision of better than 0.3 mm. The electron flux density at that position is on the order of 106^6 s−1^{-1} mm−2^{-2}. The detector board contains two silicon detector chips of p-i-n diode type which can measure the β-electron flux from the source with a precision of 0.1 % within 60 s with an energy resolution of FWHM = 2 keV. The unique challenge in developing the FBM arises from its designated operating environment inside the Cryogenic Pumping Section which is a potentially tritium contaminated ultra-high vacuum chamber at cryogenic temperatures in the presence of a 1 T strong magnetic field. Each of these parameters do strongly limit the choice of possible materials which e.g. caused difficulties in detector noise reduction, heat dissipation and lubrication. In order to completely remove the FBM from the beam tube a 2 m long traveling distance into the beamline is needed demanding a robust as well as highly precise moving mechanism

    Statistical Analysis of Different Muon-antineutrino->Electron-antineutrino Searches

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    A combined statistical analysis of the experimental results of the LSND and KARMEN \numubnueb oscillation search is presented. LSND has evidence for neutrino oscillations that is not confirmed by the KARMEN experiment. This joint analysis is based on the final likelihood results for both data sets. A frequentist approach is applied to deduce confidence regions. At a combined confidence level of 36%, there is no area of oscillation parameters compatible with both experiments. For the complementary confidence of 1-0.36=64%, there are two well defined regions of oscillation parameters (sin^2(2th),Dm^2) compatible with both experiments.Comment: 25 pages, including 10 figures, submitted to Phys. Rev.

    Characterization of the KATRIN cryogenic pumping section

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    The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to determine the effective anti-electron neutrino mass with a sensitivity of 0.2 eV/c2^2 by using the kinematics of tritium β\beta-decay. It is crucial to have a high signal rate which is achieved by a windowless gaseous tritium source producing 1011^{11} β\beta-electrons per second. These are guided adiabatically to the spectrometer section where their energy is analyzed. In order to maintain a low background rate below 0.01 cps, one essential criteria is to permanently reduce the flow of neutral tritium molecules between the source and the spectrometer section by at least 14 orders of magnitude. A differential pumping section downstream from the source reduces the tritium flow by seven orders of magnitude, while at least another factor of 107^7 is achieved by the cryogenic pumping section where tritium molecules are adsorbed on an approximately 3 K cold argon frost layer. In this paper, the results of the cryogenic pumping section commissioning measurements using deuterium are discussed. The cryogenic pumping section surpasses the requirement for the flow reduction of 107^7 by more than one order of magnitude. These results verify the predictions of previously published simulations
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