Lunar Exploration Neutron Detector (LEND) for NASA Lunar Reconnaissance Orbiter: mapping of hydrogen with high spatial resolution and determination of neutron radiation environment
Abstract
LEND parameters and design will be presented in correspondence with the main goals of this investigation: the mapping of lunar hydrogen with high special resolution and determination of neutron radiation environment on the Moon. To perform orbital measuring of neutron flux in wide energy range from thermal neutrons up to fast neutrons, the LEND instrument contain a set of nine neutron sensors. Most important part of the LEND is the Module of Collimation (MC) which consist of polyethylene and boron isotope 10B powder. The MC surrounds five neutron sensors of the instrument. Four of these sensors are high pressure 3He proportional counters covered by Cd-foil and one sensor is based on a organic scintillator crystal measures high energy neutrons with energy up to ~10 MeV. Collimator was designed such to define foot-print of 10 km diameter on the Lunar surface from the 50 km mapping orbit of the LRO spacecraft. Four additional 3He sensors mounted outside of MC are provide data about neutron environment on the LRO orbit. Two of these sensors measure thermal neutrons propagated parallel and anti-parallel to the LRO velocity vector. Two other 3He sensors mounted outside of MC provide data about thermal and epithermal neutron background onboard the spacecraft. Joint analysis of these two set of data helps to distinguish local onboard background and neutron emission from the Moon. Results of numerical simulation of LEND investigations will be also discussed together with the data from physical calibration measurements on the ground. Analysis of the first data of LEND at the lunar orbits will be presented, which demonstrate that instrument parameters correspond to the objectives of this investigations.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.U31B0027S
- Keywords:
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- 5410 PLANETARY SCIENCES: SOLID SURFACE PLANETS / Composition;
- 5462 PLANETARY SCIENCES: SOLID SURFACE PLANETS / Polar regions;
- 5464 PLANETARY SCIENCES: SOLID SURFACE PLANETS / Remote sensing