Workshop on New Views of the Moon 6036.pdf THE LUNAR PROSPECTOR NEUTRON SPECTROMETER DATA SET. S. Maurice1, W. C. Feldman2, B. L. Barraclough2, R. C. Elphic2, D. J. Lawrence2, A. B. Binder3, 1Observatoire Midi-Pyrénées, 31400 Toulouse, FRANCE, [email protected]; 2Los Alamos National Laboratory, Los Alamos, NM, 87545 USA; 3Lunar Research Institute, Gilroy, CA 95020, USA. Introduction: Lunar Prospector carries a the cruise phase showed that most, if not all, of Neutron Spectrometer (NS) whose purpose is (1) these neutrons originate from the Moon. As of late to search for hydrogen, perhaps in the form of June 98, 12 full map-cycle coverages of the Moon buried water ice at the lunar poles and/or in the have been completed. form of solar wind implanted in mature regolith The presentation will explain how the NS data and (2) to map the surface composition in Ti, Fe, set was obtained and processed. Counts integrated and KREEP. Initial analysis of the data have over portions of pulse height spectra that are low shown that NS measurements may also (3) provide in background counts will be presented as a func- valuable clues to the sub-surface temperature and, tion of the surface content in Fe and Ti. In addi- perhaps, surface thermal heat flow. The NS con- tion to these spectra, we shall detail the data of sists of two 5.7 cm diameter by 20 cm long 3He different origins that support the NS analysis: gas proportional counters. One is covered with Cd quantities that are proxies for the rate of cosmic and so responds only to epithermal neutrons (0.3 rays, as well as data that give spacecraft location eV<E<.5MeV). The other is covered with Sn and and housekeeping information. The main steps of so responds to both thermal and epithermal neu- the data processing (integrity of the 32-second trons. The difference in their counting rates pro- frames, gain drifts, latitude and altitude correc- vides a measure of the flux of thermal neutrons tions) will be discussed. We will specify the stages (E<0.3 eV). of the analysis which have been completed and the Results: Since it was powered up (Jan. 8, ones which are planned to obtain more elaborated 1998), the NS has operated flawlessly returning data products. Naturally early science results on data of excellent quality. Pulse height spectra over the science objectives mentioned above will be re- 32 channels in both energy ranges are gathered viewed. every 32 seconds. During this accumulation time, typically 600 neutrons are counted (for a space- craft altitude of 100 km). Measurements during.