A neutron activation gamma ray spectrometer for planetary surface analysis

• Published in: Acta Astronautica
• Main Authors: Bradley, J. G., Schweitzer, J. S., Truax, J. A., Rice, A., Tombrello, T. A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 1995
• Subjects: Venera; Venus; Ice cap
• Online Access: https://doi.org/10.1016/0094-5765(94)00174-K

A pulsed DT neutron generator system, similar to that used in commercial well logging, offers the possibility of performing accurate elemental analyses to depths of tens of centimeters in a few seconds with the probe on the body's surface. Through time-phased measurements of the gamma-ray spectrum synchronized with the neutron pulses, concentrations of hydrogen, carbon and key mineral forming elements can be determined even with a low-resolution spectrometer. If a high resolution spectrometer is used, the number of elements measured and the sensitivity for measurement is increased. An implanted probe system, such as in a comet or ice cap penetrator, would offer the highest possible sensitivity. An inexpensive neutron probe system based on modifications of the Schlumberger well-logging system has been proposed for the Discovery/Venera/SAGE Mission to Venus and the Mars Polar Pathfinder. Preliminary experiments on a simulated Venusian surface indicate that high quality results can be obtained. © 1995 Elsevier Science Ltd. This work was sponsored, in part, by the Director's Discretionary Fund of the Jet Propulsion Laboratory, California Institute of Technology. Significant in-kind support was provided by Schlumberger-Doll Research for the work performed in their facilities. The work described was carried out, in part, at the California Institute of Technology, at the Jet Propulsion Laboratory, California Institute of Technology under a contract with the National Aeronautics and Space Administration, and at Schlumberger-Doll Research.