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Accession Number N20120014339
Title Time-Resolved Data Acquisition for In Situ Subsurface Planetary Geochemistry.
Publication Date 2012
Media Count 40p
Personal Author A. Burger A. M. Parsons D. M. Burger J. G. Bodnarik K. G. Stassun L. G. Evans R. D. Starr
Abstract The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface geochemistry of planetary bodies in situ. All previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on a constant neutron source produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated.
Keywords Chemical composition
Data acquisition
Data processing
Gamma ray spectrometers
Gamma rays
Java(Programming language)
Neutron sources
Planetary geology
Planetary surfaces
Pulsed radiation
Remote sensing

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 54 - Astronomy & Astrophysics
84B - Extraterrestial Exploration
Corporate Author National Aeronautics and Space Administration, Cocoa Beach, FL. John F. Kennedy Space Center.
Document Type Journal article
Title Note N/A
NTIS Issue Number 1307
Contract Number N/A

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