91 research outputs found
Ocean feature recognition using genetic algorithms with fuzzy fitness functions (GA/F3)
A model for genetic algorithms with semantic nets is derived for which the relationships between concepts is depicted as a semantic net. An organism represents the manner in which objects in a scene are attached to concepts in the net. Predicates between object pairs are continuous valued truth functions in the form of an inverse exponential function (e sub beta lxl). 1:n relationships are combined via the fuzzy OR (Max (...)). Finally, predicates between pairs of concepts are resolved by taking the average of the combined predicate values of the objects attached to the concept at the tail of the arc representing the predicate in the semantic net. The method is illustrated by applying it to the identification of oceanic features in the North Atlantic
Using the Fermilab Proton Source for a Muon to Electron Conversion Experiment
The Fermilab proton source is capable of providing 8 GeV protons for both the
future long-baseline neutrino program (NuMI), and for a new program of low
energy muon experiments. In particular, if the 8 GeV protons are rebunched and
then slowly extracted into an external beamline, the resulting proton beam
would be suitable for a muon-to-electron conversion experiment designed to
improve on the existing sensitivity by three orders of magnitude. We describe a
scheme for the required beam manipulations. The scheme uses the Accumulator for
momentum stacking, and the Debuncher for bunching and slow extraction. This
would permit simultaneous operation of the muon program with the future NuMI
program, delivering 10^20 protons per year at 8 GeV for the muon program at the
cost of a modest (~10%) reduction in the protons available to the neutrino
program.Comment: 18 pages, 7 figure
The NuMAX Long Baseline Neutrino Factory Concept
A Neutrino Factory where neutrinos of all species are produced in equal
quantities by muon decay is described as a facility at the intensity frontier
for exquisite precision providing ideal conditions for ultimate neutrino
studies and the ideal complement to Long Baseline Facilities like LBNF at
Fermilab. It is foreseen to be built in stages with progressively increasing
complexity and performance, taking advantage of existing or proposed facilities
at an existing laboratory like Fermilab. A tentative layout based on a
recirculating linac providing opportunities for considerable saving is
discussed as well as its possible evolution toward a muon collider if and when
requested by Physics. Tentative parameters of the various stages are presented
as well as the necessary R&D to address the technological issues and
demonstrate their feasibility.Comment: JINST Special Issue on Muon Accelerators. arXiv admin note: text
overlap with arXiv:1308.0494, arXiv:1502.0164
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Preparations for Muon Experiments at Fermilab
The use of existing Fermilab facilities to provide beams for two muon experiments--the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment--is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration
Universal Extra Dimensions and Kaluza Klein Bound States
We study the bound states of the Kaluza-Klein (KK) excitations of quarks in
certain models of Universal Extra Dimensions. Such bound states may be detected
at future lepton colliders in the cross section for the pair production of
KK-quarks near threshold. For typical values of model parameters, we find that
"KK-quarkonia" have widths in the 10 - 100 MeV range, and production cross
sections of order a few picobarns for the lightest resonances. Two body decays
of the constituent KK-quarks lead to distinctive experimental signatures. We
point out that such KK resonances may be discovered before any of the higher KK
modes.Comment: 21 pages LaTeX, 9 eps figure
An Integrated Circuit for Signal Processing of the AMS RICH Photmultipliers Tubes
An analog integrated circuit has been designed, in a BiCMOS 0.8 micron
technology, for the feasability study of the signal processing of the AMS RICH
photomultiplier tubes. This low power, three channel gated integrator includes
its own gate and no external analog delay is requiered. It processes PMT pulses
over a dynamic range of more than 100. A logic output that indicates whether
the analog charge has to be considered is provided. This gated integrator is
used with a compact DSP based acquisition system in a 132 channels RICH
prototype. The charge calibration of each channel is carried out using a LED.
The pedestal measurement is performed on activation of a dedicated input. The
noise contribution study of the input RC network and amplifiers is presented.Comment: IEEE symp. on Nucl. Sci. and Med. Imaging, Toront
Studies of Breakdown in a Pressurized RF Cavity
Microscopic images of the surfaces of metallic electrodes used in high-pressure gas-filled 805 MHz RF cavity experiments [1] have been used to investigate the mechanism of RF breakdown [2]. The images show evidence for melting and boiling in small regions of ∼10 micron diameter on tungsten, molybdenum, and beryllium electrode surfaces. In these experiments, the dense hydrogen gas in the cavity prevents electrons or ions from being accelerated to high enough energy to participate in the breakdown process so that the only important variables are the fields and the metallic surfaces. The distributions of breakdown remnants on the electrode surfaces are compared to the maximum surface gradient E predicted by an ANSYS model of the cavity. The local surface density of spark remnants, proportional to the probability of breakdown, shows a strong exponential dependence on the maximum gradient, which is reminiscent of Fowler-Nordheim behavior of electron emission from a cold cathode. New simulation results have shown good agreement with the breakdown behaviour of the hydrogen gas in the Paschen region and have suggested improved behaviour with the addition of trace dopants such as SF6 [3]. Present efforts are to extend the computer model to include electrode breakdown phenomena and to use scanning tunnelling microscopy to search for work function differences between the conditioned and unconditioned parts of the electrodes
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Isochronous pion decay channel for enhanced muon capture
Intense muon beams have many potential applications, including neutrino factories and muon colliders. However, muons are produced in tertiary beams into a diffuse phase space. To make useful beams, the muons must be rapidly cooled before they decay. A promising new concept for the collection and cooling of muon beams is being investigated, namely, the use of a nearly Isochronous Helical Transport Channel (IHTC) to facilitate capture of muons into RF bunches. Such a distribution could be cooled quickly and coalesced into a single bunch to optimize the luminosity of a muon collider. We describe the IHTC and provide simulations demonstrating isochronicity, even in the absence of RF and absorber
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Integrating the MANX 6-D Muon Cooling Experiment with the MICE Spectrometers
The MANX experiment is to demonstrate the reduction of 6D muon phase space emittance using a continuous liquid absorber to provide ionization cooling in a helical solenoid magnetic channel. The experiment involves the construction of a short two-period long helical cooling channel (HCC) to reduce the muon invariant emittance by a factor of two. The HCC would replace the current cooling section of the MICE experiment now being setup at the Rutherford Appleton Laboratory. The MANX experiment would use the existing MICE spectrometers and muon beam line. This paper shall consider the various approaches to integrate MANX into the RAL hall using the MICE spectrometers. This study shall discuss the matching schemes used to minimize losses and prevent emittance growth between the MICE spectrometers and the MANX HCC. Also the placement of additional detection planes in the matching region and the HCC to improve the resolution will be examined
NON-MAGNETIC MOMENTUM SPECTROMETER BASED ON FAST TIME-OF-FLIGHT SYSTEM
Abstract A new generation of large-area, low cost time-of-flight detectors with time resolutions ≤ 10 ps and space resolutions ≤ 1 mm is being developed for use in nuclear and particle physics experiments, as well as for medical and industrial applications. Such detectors can serve as the basis for measuring momenta without requiring measurement of curvature in magnetic fields. Factors affecting measurement accuracy and simulation results are presented
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