The effect of craters on the lunar neutron flux.
The variation of remotely sensed neutron count rates is measured as a function of cratercentric distance using data from the Lunar Prospector Neutron Spectrometer. The count rate, stacked over many craters, peaks over the crater center, has a minimum near the crater rim, and at larger distances, it...
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American Geophysical Union
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ftunivdurham:oai:dro.dur.ac.uk.OAI2:16821 2023-05-15T18:22:56+02:00 The effect of craters on the lunar neutron flux. Eke, V. R. Bower, K. E. Diserens, S. Ryder, M. Yeomans, P. E. L. Teodoro, L. F. A. Elphic, R. C. Feldman, W. C. Hermalyn, B. Lavelle, C. M. Lawrence, D. J. 2015-08-13 application/pdf http://dro.dur.ac.uk/16821/ http://dro.dur.ac.uk/16821/1/16821.pdf https://doi.org/10.1002/2015JE004856 unknown American Geophysical Union dro:16821 issn:2169-9097 issn: 2169-9100 doi:10.1002/2015JE004856 http://dro.dur.ac.uk/16821/ https://doi.org/10.1002/2015JE004856 http://dro.dur.ac.uk/16821/1/16821.pdf Eke, V. R., K. E. Bower, S. Diserens, M. Ryder, P. E. L. Yeomans, L. F. A. Teodoro, R. C. Elphic, W. C. Feldman, B. Hermalyn, C. M. Lavelle, et al. (2015), The effect of craters on the lunar neutron flux, Journal of Geophysical Research: Planets, 120, 1377-1395, doi:10.1002/2015JE004856. To view the published open abstract, go to https://doi.org and enter the DOI. Journal of geophysical research : planets, 2015, Vol.120(8), pp.1377-1395 [Peer Reviewed Journal] Moon Article PeerReviewed 2015 ftunivdurham https://doi.org/10.1002/2015JE004856 2020-05-28T22:33:31Z The variation of remotely sensed neutron count rates is measured as a function of cratercentric distance using data from the Lunar Prospector Neutron Spectrometer. The count rate, stacked over many craters, peaks over the crater center, has a minimum near the crater rim, and at larger distances, it increases to a mean value that is up to 1% lower than the mean count rate observed over the crater. A simple model is presented, based upon an analytical topographical profile for the stacked craters fitted to data from the Lunar Orbiter Laser Altimeter. The effect of topography coupled with neutron beaming from the surface largely reproduces the observed count rate profiles. However, a model that better fits the observations can be found by including the additional freedom to increase the neutron emissivity of the crater area by ∼0.35% relative to the unperturbed surface. It is unclear what might give rise to this effect, but it may relate to additional surface roughness in the vicinities of craters. The amplitude of the crater-related signal in the neutron count rate is small, but not too small to demand consideration when inferring water-equivalent hydrogen (WEH) weight percentages in polar permanently shaded regions (PSRs). If the small crater-wide count rate excess is concentrated into a much smaller PSR, then it can lead to a large bias in the inferred WEH weight percentage. For instance, it may increase the inferred WEH for Cabeus crater at the Moon's south pole from ∼1% to ∼4%. Article in Journal/Newspaper South pole Durham University: Durham Research Online South Pole Journal of Geophysical Research: Planets 120 8 1377 1395 |
institution |
Open Polar |
collection |
Durham University: Durham Research Online |
op_collection_id |
ftunivdurham |
language |
unknown |
topic |
Moon |
spellingShingle |
Moon Eke, V. R. Bower, K. E. Diserens, S. Ryder, M. Yeomans, P. E. L. Teodoro, L. F. A. Elphic, R. C. Feldman, W. C. Hermalyn, B. Lavelle, C. M. Lawrence, D. J. The effect of craters on the lunar neutron flux. |
topic_facet |
Moon |
description |
The variation of remotely sensed neutron count rates is measured as a function of cratercentric distance using data from the Lunar Prospector Neutron Spectrometer. The count rate, stacked over many craters, peaks over the crater center, has a minimum near the crater rim, and at larger distances, it increases to a mean value that is up to 1% lower than the mean count rate observed over the crater. A simple model is presented, based upon an analytical topographical profile for the stacked craters fitted to data from the Lunar Orbiter Laser Altimeter. The effect of topography coupled with neutron beaming from the surface largely reproduces the observed count rate profiles. However, a model that better fits the observations can be found by including the additional freedom to increase the neutron emissivity of the crater area by ∼0.35% relative to the unperturbed surface. It is unclear what might give rise to this effect, but it may relate to additional surface roughness in the vicinities of craters. The amplitude of the crater-related signal in the neutron count rate is small, but not too small to demand consideration when inferring water-equivalent hydrogen (WEH) weight percentages in polar permanently shaded regions (PSRs). If the small crater-wide count rate excess is concentrated into a much smaller PSR, then it can lead to a large bias in the inferred WEH weight percentage. For instance, it may increase the inferred WEH for Cabeus crater at the Moon's south pole from ∼1% to ∼4%. |
format |
Article in Journal/Newspaper |
author |
Eke, V. R. Bower, K. E. Diserens, S. Ryder, M. Yeomans, P. E. L. Teodoro, L. F. A. Elphic, R. C. Feldman, W. C. Hermalyn, B. Lavelle, C. M. Lawrence, D. J. |
author_facet |
Eke, V. R. Bower, K. E. Diserens, S. Ryder, M. Yeomans, P. E. L. Teodoro, L. F. A. Elphic, R. C. Feldman, W. C. Hermalyn, B. Lavelle, C. M. Lawrence, D. J. |
author_sort |
Eke, V. R. |
title |
The effect of craters on the lunar neutron flux. |
title_short |
The effect of craters on the lunar neutron flux. |
title_full |
The effect of craters on the lunar neutron flux. |
title_fullStr |
The effect of craters on the lunar neutron flux. |
title_full_unstemmed |
The effect of craters on the lunar neutron flux. |
title_sort |
effect of craters on the lunar neutron flux. |
publisher |
American Geophysical Union |
publishDate |
2015 |
url |
http://dro.dur.ac.uk/16821/ http://dro.dur.ac.uk/16821/1/16821.pdf https://doi.org/10.1002/2015JE004856 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_source |
Journal of geophysical research : planets, 2015, Vol.120(8), pp.1377-1395 [Peer Reviewed Journal] |
op_relation |
dro:16821 issn:2169-9097 issn: 2169-9100 doi:10.1002/2015JE004856 http://dro.dur.ac.uk/16821/ https://doi.org/10.1002/2015JE004856 http://dro.dur.ac.uk/16821/1/16821.pdf |
op_rights |
Eke, V. R., K. E. Bower, S. Diserens, M. Ryder, P. E. L. Yeomans, L. F. A. Teodoro, R. C. Elphic, W. C. Feldman, B. Hermalyn, C. M. Lavelle, et al. (2015), The effect of craters on the lunar neutron flux, Journal of Geophysical Research: Planets, 120, 1377-1395, doi:10.1002/2015JE004856. To view the published open abstract, go to https://doi.org and enter the DOI. |
op_doi |
https://doi.org/10.1002/2015JE004856 |
container_title |
Journal of Geophysical Research: Planets |
container_volume |
120 |
container_issue |
8 |
container_start_page |
1377 |
op_container_end_page |
1395 |
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1766202345085992960 |