7,273 research outputs found
Space Shuttle/TDRSS communication and tracking systems analysis
In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed
On Determining Dead Layer and Detector Thicknesses for a Position-Sensitive Silicon Detector
In this work, two particular properties of the position-sensitive, thick
silicon detectors (known as the "E" detectors) in the High Resolution Array
(HiRA) are investigated: the thickness of the dead layer on the front of the
detector, and the overall thickness of the detector itself. The dead layer
thickness for each E detector in HiRA is extracted using a measurement of alpha
particles emitted from a Pb pin source placed close to the detector
surface. This procedure also allows for energy calibrations of the E detectors,
which are otherwise inaccessible for alpha source calibration as each one is
sandwiched between two other detectors. The E detector thickness is obtained
from a combination of elastically scattered protons and an energy-loss
calculation method. Results from these analyses agree with values provided by
the manufacturer.Comment: Accepted for publication in Nuclear Instruments and Methods in
Physics Researc
Long-range surface plasmon polariton excitation at the quantum level
We provide the quantum mechanical description of the excitation of long-range
surface plasmon polaritons (LRSPPs) on thin metallic strips. The excitation
process consists of an attenuated-reflection setup, where efficient
photon-to-LRSPP wavepacket-transfer is shown to be achievable. For calculating
the coupling, we derive the first quantization of LRSPPs in the polaritonic
regime. We study quantum statistics during propagation and characterize the
performance of photon-to-LRSPP quantum state transfer for single-photons,
photon-number states and photonic coherent superposition states.Comment: 9 pages, 6 figures, RevTeX4; Accepted versio
Interplay of initial deformation and Coulomb proximity on nuclear decay
Alpha particles emitted from an excited projectile-like fragment (PLF*)
formed in a peripheral collision of two intermediate-energy heavy ions exhibit
a strong preference for emission towards the target-like fragment (TLF). The
interplay of the initial deformation of the PLF* caused by the reaction,
Coulomb proximity, and the rotation of the PLF* results in the observed
anisotropic angular distribution. Changes in the shape of the angular
distribution with excitation energy are interpreted as being the result of
forming more elongated initial geometries in the more peripheral collisions.Comment: 4 figure
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