1,908 research outputs found
A New Scintillator Tile/Fiber Preshower Detector for the CDF Central Calorimeter
A detector designed to measure early particle showers has been installed in
front of the central CDF calorimeter at the Tevatron. This new preshower
detector is based on scintillator tiles coupled to wavelength-shifting fibers
read out by multi-anode photomultipliers and has a total of 3,072 readout
channels. The replacement of the old gas detector was required due to an
expected increase in instantaneous luminosity of the Tevatron collider in the
next few years. Calorimeter coverage, jet energy resolution, and electron and
photon identification are among the expected improvements. The final detector
design, together with the R&D studies that led to the choice of scintillator
and fiber, mechanical assembly, and quality control are presented. The detector
was installed in the fall 2004 Tevatron shutdown and started collecting
colliding beam data by the end of the same year. First measurements indicate a
light yield of 12 photoelectrons/MIP, a more than two-fold increase over the
design goals.Comment: 5 pages, 10 figures (changes are minor; this is the final version
published in IEEE-Trans.Nucl.Sci.
Design and construction of new central and forward muon counters for CDF II
New scintillation counters have been designed and constructed for the CDF
upgrade in order to complete the muon coverage of the central CDF detector, and
to extend this coverage to larger pseudorapidity. A novel light collection
technique using wavelength shifting fibers, together with high quality
polystyrene-based scintillator resulted in compact counters with good and
stable light collection efficiency over lengths extending up to 320 cm. Their
design and construction is described and results of their initial performance
are reported.Comment: 20 pages, 15 figure
Understanding Farmers’ Forecast Use from Their Beliefs, Values, Social Norms, and Perceived Obstacles
Although the accuracy of weather and climate forecasts is continuously improving and new information retrieved from climate data is adding to the understanding of climate variation, use of the forecasts and climate information by farmers in farming decisions has changed little. This lack of change may result from knowledge barriers and psychological, social, and economic factors that undermine farmer motivation to use forecasts and climate information. According to the theory of planned behavior (TPB), the motivation to use forecasts may arise from personal attitudes, social norms, and perceived control or ability to use forecasts in specific decisions. These attributes are examined using data from a survey designed around the TPB and conducted among farming communities in the region of eastern Nebraska and the western U.S. Corn Belt. There were three major findings: 1) the utility and value of the forecasts for farming decisions as perceived by farmers are, on average, around 3.0 on a 0–7 scale, indicating much room to improve attitudes toward the forecast value. 2) The use of forecasts by farmers to influence decisions is likely affected by several social groups that can provide “expert viewpoints” on forecast use. 3) A major obstacle, next to forecast accuracy, is the perceived identity and reliability of the forecast makers. Given the rapidly increasing number of forecasts in this growing service business, the ambiguous identity of forecast providers may have left farmers confused and may have prevented them from developing both trust in forecasts and skills to use them. These findings shed light on productive avenues for increasing the influence of forecasts, which may lead to greater farming productivity. In addition, this study establishes a set of reference points that can be used for comparisons with future studies to quantify changes in forecast use and influence
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