652 research outputs found
Simulations of the nEDM@SNS light collection system efficiency
A system for collecting the scintillation light produced by the capture
process of ultra-cold neutrons (UCN) on polarized He is discussed and
results from simulations of its performance are presented. This system will be
implemented in nEDM@SNS, the experiment searching for the neutron electric
dipole moment (nEDM) at the Spallation Neutron Source (SNS) at Oak Ridge
National Laboratory. Simulation results show that the light collection system
collects on average 17 photoelectrons per UCN-He capture event
(sufficient to generate a robust signal), reconstructs the event location in
the beam direction to approximately 3 cm accuracy, detects capture events with
a high and spatially uniform efficiency (0.95 with 1% variation), and rejects
greater than 50% of beta decay background events.Comment: 14 pages, 13 figures. Submitted to Journal of Instrumentatio
Integrated Flush Air Data Sensing System Modeling for Planetary Entry Guidance with Direct Force Control
Flush air data sensing (FADS) systems have been previously used at both Earth and Mars to provide onboard estimates of angle of attack, sideslip angle, and dynamic pressure. However, these FADS data were often not used in an in-the-loop sense to inform the onboard guidance and control systems. A method to integrate FADS-derived density and wind estimates with a numerical predictor-corrector guidance algorithm is presented. The method is demonstrated in a high-fidelity simulation of a human-scale Mars entry vehicle that utilizes a hypersonic inflatable aerodynamic decelerator (HIAD) with direct force control. Effects on guidance commands and state uncertainties both with and without FADS system modeling are presented and discussed
Large Mass, Entry, Descent and Landing Sensitivity Results for Environmental, Performance, and Design Parameters
Landing on Mars has been a challenging task. Past NASA missions have shown resilience to increases in spacecraft mass by scaling back requirements such as landing site altitude, landing site location and arrival time. Knowledge of the partials relating requirements to mass is critical for mission designers to understand so that the project can retain margin throughout the process. Looking forward to new missions that will land 1.5 metric tons or greater, the current level of technology is insufficient, and new technologies will need to be developed. Understanding the sensitivity of these new technologies to requirements is the purpose of this paper
Discovering the New Standard Model: Fundamental Symmetries and Neutrinos
This White Paper describes recent progress and future opportunities in the
area of fundamental symmetries and neutrinos.Comment: Report of the Fundamental Symmetries and Neutrinos Workshop, August
10-11, 2012, Chicago, I
A Study of the (3-He,t) Charge-Exchange Reaction at E(3-He) = 200 MeV
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Inclusive Soft Pion Production from 12.3 and 17.5 GeV/c Protons on Be, Cu and Au
Differential cross-sections are presented for the inclusive production of
charged pions in the momentum range 0.1 to 1.2 GeV/c in interactions of 12.3
and 17.5 GeV/c protons with Be, Cu, and Au targets. The measurements were made
by Experiment 910 at the Alternating Gradient Synchrotron in Brookhaven
National Laboratory. The cross-sections are presented as a function of pion
total momentum and production polar angle with respect to the beam.Comment: 14 pages, 8 figure
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