13,179 research outputs found
Performance of the OPAL Si-W luminometer at LEP I-II
A pair of compact Silicon-Tungsten calorimeters was operated in the OPAL
experiment at LEP to measure the integrated luminosity from detection of Bhabha
electrons scattered at angles between 25 and 58 mrad from the beam line. In the
eight years from 1993 to 2000 the detector worked first at the Z mass peak and
then at center of mass energies up to 209 GeV. The fine radial and longitudinal
segmentation (2.5mm x 1X0) allowed the radial position of electron and photon
showers to be measured with a resolution of 130-170 microns and a residual
radial bias as small as 7 microns. Reducing the bias in the definition of the
inner acceptance radius was the key element in obtaining an experimental
systematic error on the integrated luminosity of only 3.4 10^-4. The
performance of the detector at both LEP-I and LEP-II is reviewed. Energy
resolution, sensitivity to overlapping electromagnetic showers and sensitivity
to minimum ionizing particles are discussed.Comment: 9 pages, 7 figures, 10th International Conference on Calorimetry in
High Energy Physics. http://3w.hep.caltech.edu/calor02
Arkansas Animal Science Department Report 2002
The faculty and staff of the Animal Science Program are pleased to present the sixth edition of the Arkansas Animal Science Report. As with virtually all programs in the country, budget constraints presented serious challenges to teaching, research, and extension programming. However, the faculty and staff responded with innovation, good management, and hard work to maintain a productive program designed to benefit the students of the University and the citizens of the state. We are committed to remaining faithful to our Land-Grant mission. A sincere thank you is owed to Dr. Zelpha Johnson and Dr. Wayne Kellogg for editing this publication. We are proud that Meat and Poultry magazine ranked the animal and poultry programs at the University of Arkansas among the top four in the United States for 2003. This is a tribute to the dedicated and talented faculty in the Departments of Animal Science, Poultry Science, and Food Science and to their high level of cooperation
Milking management and housing studies
Digitized 2007 AES.Includes bibliographical references (page 10)
A compact high-flux cold atom beam source
We report on an efficient and compact high-flux Cs atom beam source based on
a retro-reflected two-dimensional magneto-optical trap (2D MOT). We realize an
effective pushing field component by tilting the 2D MOT collimators towards a
separate three-dimensional magneto-optical trap (3D MOT) in ultra-high vacuum.
This technique significantly improved 3D MOT loading rates to greater than atoms/s using only 20 mW of total laser power for the source. When
operating below saturation, we achieve a maximum efficiency of atoms/s/W
Solar Wind Electric Fields in the Ion Cyclotron Frequency Range
Measurements of fluctuations of electric fields in the frequency range from a
fraction of one Hz to 12.5 Hz are presented, and corrected for the Lorentz
transformation of magnetic fluctuations to give the electric fields in the
plasma frame. The electric fields are large enough to provide the dominant
force on the ions of the solar wind in the region near the ion cyclotron
frequency of protons, larger than the force due to magnetic fluctuations. They
provide sufficient velocity space diffusion or heating to counteract
conservation of magnetic moment in the expanding solar wind to maintain nearly
isotropic velocity distributions
Motion sickness susceptibility under weightless and hypergravity conditions generated by parabolic flight
Motion sickness susceptibility under weightless and hypergravity conditions generated by parabolic fligh
Extragalactic H 2 regions in the UV: Implications for primeval galaxies and quasars
Three extragalactic regions of rapid star formation with red shifts great enough to separate the L alpha region from geocoronal L alpha were observed with the IUE satellite. Only the low metal abundance object had detectable L alpha emission. L alpha is therefore expected to be weak or absent in collapsed primeval galaxies. The detected object has a L alpha H beta identical to that of quasars
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