{"id":10036,"date":"2016-09-30T06:59:21","date_gmt":"2016-09-30T04:59:21","guid":{"rendered":"http:\/\/karmaka.de\/?p=10036"},"modified":"2016-09-30T06:59:21","modified_gmt":"2016-09-30T04:59:21","slug":"modeling-orbital-gamma-ray-spectroscopy-experiments-at-carbonaceous-asteroids","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=10036","title":{"rendered":"Modeling Orbital Gamma-Ray Spectroscopy Experiments at Carbonaceous Asteroids<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>Lucy F. Lim, Richard D. Starr, Larry G. Evans, Ann M. Parsons, Michael E. Zolensky, William V. Boynton<\/p>\n<p>Accepted to Meteoritics and Planetary Science, September 2016 <\/p>\n<p><a href=\"http:\/\/arxiv.org\/pdf\/1609.09442\" target=\"_blank\"><strong>PDF (OPEN ACCESS)<\/strong><\/a><br \/>\n<a href=\"http:\/\/arxiv.org\/abs\/1609.09442\" target=\"_blank\"><strong>abstract<\/strong><\/a><\/p>\n<p>&#8220;To evaluate the feasibility of measuring differences in bulk composition among carbonaceous meteorite parent bodies from an asteroid or comet orbiter, we present the results of a performance simulation of an orbital gamma-ray spectroscopy (&#8220;GRS&#8221;) experiment in a Dawn-like orbit around spherical model asteroids with a range of carbonaceous compositions. The orbital altitude was held equal to the asteroid radius for 4.5 months. Both the asteroid gamma-ray spectrum and the spacecraft background flux were calculated using the MCNPX Monte-Carlo code. GRS is sensitive to depths below the optical surface (to ~20&#8211;50 cm depth depending on material density). This technique can therefore measure underlying compositions beneath a sulfur-depleted (e.g., Nittler et al. 2001) or desiccated surface layer. We find that 3\\sigma\\ uncertainties of under 1 wt% are achievable for H, C, O, Si, S, Fe, and Cl for five carbonaceous meteorite compositions using the heritage Mars Odyssey GRS design in a spacecraft- deck-mounted configuration at the Odyssey end-of-mission energy resolution, FWHM = 5.7 keV at 1332 keV. The calculated compositional uncertainties are smaller than the compositional differences between carbonaceous chondrite subclasses. &#8220;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Lucy F. Lim, Richard D. Starr, Larry G. Evans, Ann M. Parsons, Michael E. Zolensky, William V. Boynton Accepted to Meteoritics and Planetary Science, September 2016 PDF (OPEN ACCESS) abstract &#8220;To evaluate the feasibility of&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,127],"tags":[3274,3275,3276],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10036"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10036"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10036\/revisions"}],"predecessor-version":[{"id":10037,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/10036\/revisions\/10037"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10036"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10036"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10036"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}