12,100 research outputs found
Spacelab mission dependent training parametric resource requirements study
Training flows were developed for typical missions, resource relationships analyzed, and scheduling optimization algorithms defined. Parametric analyses were performed to study the effect of potential changes in mission model, mission complexity and training time required on the resource quantities required to support training of payload or mission specialists. Typical results of these analyses are presented both in graphic and tabular form
Anode-Coupled Readout for Light Collection in Liquid Argon TPCs
This paper will discuss a new method of signal read-out from photon detectors
in ultra-large, underground liquid argon time projection chambers. In this
design, the signal from the light collection system is coupled via capacitive
plates to the TPC wire-planes. This signal is then read out using the same
cabling and electronics as the charge information. This greatly benefits light
collection: it eliminates the need for an independent readout, substantially
reducing cost; It reduces the number of cables in the vapor region of the TPC
that can produce impurities; And it cuts down on the number of feed-throughs in
the cryostat wall that can cause heat-leaks and potential points of failure. We
present experimental results that demonstrate the sensitivity of a LArTPC wire
plane to photon detector signals. We also simulate the effect of a 1 s
shaping time and a 2 MHz sampling rate on these signals in the presence of
noise, and find that a single photoelectron timing resolution of 30 ns
can be achieved.Comment: 16 pages, 15 figure
Improved TPB-coated Light Guides for Liquid Argon TPC Light Detection Systems
Scintillation light produced in liquid argon (LAr) must be shifted from 128
nm to visible wavelengths in light detection systems used for liquid argon
time-projection chambers (LArTPCs). To date, LArTPC light collection systems
have employed tetraphenyl butadiene (TPB) coatings on photomultiplier tubes
(PMTs) or plates placed in front of the PMTs. Recently, a new approach using
TPB-coated light guides was proposed. In this paper, we report on light guides
with improved attenuation lengths above 100 cm when measured in air. This is an
important step in the development of meter-scale light guides for future
LArTPCs. Improvements come from using a new acrylic-based coating,
diamond-polished cast UV transmitting acrylic bars, and a hand-dipping
technique to coat the bars. We discuss a model for connecting bar response in
air to response in liquid argon and compare this to data taken in liquid argon.
The good agreement between the prediction of the model and the measured
response in liquid argon demonstrates that characterization in air is
sufficient for quality control of bar production. This model can be used in
simulations of light guides for future experiments.Comment: 25 pages, 20 figure
Upheaval Dome, An Analogue Site for Gale Center
We propose Upheaval Dome in southeastern Utah as an impact analogue site on Earth to Mars Science Laboratory candidate landing site Gale Crater. The genesis of Upheaval Dome was a mystery for some time--originally thought to be a salt dome. The 5 km crater was discovered to possess shocked quartz and other shock metamorphic features just a few years ago, compelling evidence that the crater was formed by impact, although the structural geology caused Shoemaker and Herkenhoff to speculate an impact origin some 25 years earlier. The lithology of the crater is sedimentary. The oldest rocks are exposed in the center of the dome, upper Permian sandstones, and progressively younger units are well exposed moving outward from the center. These are Triassic sandstones, siltstones and shales, which are intruded by clastic dikes. There are also other clay-rich strata down section, as is the case with Gale Crater. There is significant deformation in the center of the crater, with folding and steeply tilted beds, unlike the surrounding Canyonlands area, which is relatively undeformed. The rock units are well exposed at Upheaval Dome, and there are shatter cones, impactite fragments, shocked quartz grains and melt rocks present. The mineral shock features suggest that the grains were subjected to dynamic pressures> 10 GPa
UNLV New Horizons Band & Red Rock Saxophone Quartet & UNLV Symphonic Winds
Program listing performers and works performed
Cyclotrons as Drivers for Precision Neutrino Measurements
As we enter the age of precision measurement in neutrino physics, improved
flux sources are required. These must have a well-defined flavor content with
energies in ranges where backgrounds are low and cross section knowledge is
high. Very few sources of neutrinos can meet these requirements. However,
pion/muon and isotope decay-at-rest sources qualify. The ideal drivers for
decay-at-rest sources are cyclotron accelerators, which are compact and
relatively inexpensive. This paper describes a scheme to produce decay-at-rest
sources driven by such cyclotrons, developed within the DAEdALUS program.
Examples of the value of the high precision beams for pursuing Beyond Standard
Model interactions are reviewed. New results on a combined DAEdALUS--Hyper-K
search for CP-violation that achieve errors on the mixing matrix parameter of 4
degrees to 12 degrees are presented.Comment: This paper was invited by the journal Advances in High Energy Physics
for their upcoming special issue on "Neutrino Masses and Oscillations," which
will be published on the 100th anniversary of Pontecorvo's birt
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