[en] With its heavy water target, the Sudbury Neutrino Observatory has the unique opportunity to measure both the ⁸B flux of electron neutrinos from the Sun and the flux of all active neutrino species independently, thus offering a direct and model-independent test of a neutrino oscillation solution to the solar neutrino problem. The authors report on the physics intent and design of a discrete method of neutral-current detection in the Sudbury neutrino observatory that will utilize ultra-low background ³He proportional counters dispersed throughout the heavy water volume. Projections of background in all components of the detector are considered in an analysis of the ability to extract the neutral-current signal and the neutral-current to charged-current ratio

No abstract available

[en] The author has measured the flavor ratio of ratios (R) in atmospheric neutrino interactions using a 1.52 kton-year exposure of Soudan 2. He finds R 0.67 ± 0.15_-0.06^+0.04. This value is about 2σ from the expected value of 1.0 and is consistent with the anomalous ratios measured by the Kamiokande and IMB experiments. He notes that since the acceptance matrix is different from those of the water Cherenkov experiments he would not expect to measure the same value of R, unless R = 1

[en] The Asymmetric B-Factory at the Stanford Linear Accelerator Center will study the B-anti B meson system with focus on CP violation. Its detector BaBar contains a high-resolution CsI(Tl) calorimeter, which is currently under construction. The final design of the calorimeter (from the crystals to the calibration system) will be presented in this report

[en] The 32-channel time-to-digital converter M1102 Multihit TDC is described. The time measurement is based on the direct transformation method. The presence of the digital interpolator permits one to achieve the time resolution of 2 ns, for 64 MHz clock. The dead time of the measuring channel composes 80 ns, the time measuring range - 8 μs. The time measurement is possible in the regimes of 'general start' and 'general stop'. The module is manufactured in the CAMAC standard

[en] The ATLAS detector at CERN is an experiment on the future LHC collider, which seeks new particles, like the Higgs boson, to complete the standard model and develop the supersymmetry model. An important sub-detector in ATLAS is the Liquid Argon calorimeter which measures the energy of electrons and photons. The calorimeter precision is partially limited by the electronic noise of the input preamplifiers, which is then particularly a point of attention. The main study of this thesis is a 'warm' current preamplifier ('0T') placed outside the cryostat, the signal being driven on cables. First, the main characteristics of another type of preamplifier placed in the calorimeter are studied. Then the 0T is modelled, particularly the effects of a cable on the electronic noise and the signal. Different versions are studied, whose measurements are in good agreement with expected values. In the ATLAS Liquid Argon calorimeter conditions the 0T performance are very competitive with a 'cold' preamp, and has the advantage of reliability. Also their location outside the cryostat allows maintenance. But the cable impedance is higher than the input impedance of a cold preamplifier, which is a drawback according to capacitive crosstalk between neighbouring channels. The signal crosstalk is higher, but acceptable. As well, the noise correlation between two channels as a function of cable length is shown as negligible for cable lengths used. The noise autocorrelation function is also studied to optimize a multi-sampling filtering. The model and measurements are in excellent agreement. The 0T has been chosen to equip 200,000 channels of the ATLAS Liquid Argon calorimeter. (author)

[en] The Endcap Cryostat will be supported by the End Barrel Tilecalorimeter at four points. The outer support points will be carried by a structure that is external to the End Barrel modules while the inner support points will be directly on the modules. This paper concerns the design of these inner support points. The design parameters for the inner support points are: (1) must be able to support twice the front load from the Endcap Cryostat (70 tons); (2) the support point must make contact on the inner radius surface provided on the Endcap Cryostat; (3) vertical adjust must be allowed of up to ± 6mm; (4) the support must be a simple support; (5) the support must be contained within the envelope of one End Barrel submodule

[en] The girder at the back of each module plays an important structural role in the assembly of the Tilecalorimeter barrel. It is important, therefore, to clearly understand the welds within the girder. In order to understand the stresses in the welds, a 2-dimensional finite element model has been constructed of the girder cross section similar to the model that has been previously used by J. Blocki to analyze the girder. The current European welding norms do not require stress concentrations within welds to be considered except under fatigue loading conditions. Since this is not the case for this design, the use of the average stress in sizing the welds is allowed under the European welding norms. An analysis of the welds by V. Romanov that only considered the average stress, showed that the average weld stress was 38N/mm², well within acceptable limits. However, it should be kept in mind that the forces on the welds vary significantly along the length of the girder so the average stress may not be an adequate method of analyzing these welds. In addition, since these welds are so critical to the structural integrity of the Tilecalorimeter, it is desirable to examine stress concentrations even though this is not required by the european norms. Therefore, it is recommended that a 30mm wide bar as shown in Figure 3 be used on the ten modules that see the highest load from the cryostat. This is a very simple and low-cost modification to a small number of girders that will provide significant additional safety

[en] Prevention of electromagnetic interference (EMI), or ''noise pickup,'' is an important design aspect in large detectors in accelerator environments. Shielding effectiveness as a function of shield thickness and conductivity vs the type and frequency of the interference field is described. Noise induced in transmission lines by ground loop driven currents in the shield is evaluated and the importance of low shield resistance is emphasized. Some measures for prevention of ground loops and isolation of detector-readout systems are discussed

No abstract available