{"id":1265,"date":"2017-10-27T11:59:13","date_gmt":"2017-10-27T15:59:13","guid":{"rendered":"https:\/\/wpstaging.whoi.edu\/site\/nosams\/?p=1265"},"modified":"2020-05-18T14:06:50","modified_gmt":"2020-05-18T18:06:50","slug":"hybrid-gas-ion-source-development","status":"publish","type":"post","link":"https:\/\/www2.whoi.edu\/site\/nosams\/hybrid-gas-ion-source-development\/","title":{"rendered":"Hybrid Gas Ion Source Development"},"content":{"rendered":"<p>NOSAMS has installed a hybrid gas ion source from NEC as the final stage in upgrading the NOSAMS Tandetron AMS system (USAMS). This source can run either graphite samples or carbon dioxide (CO<sub>2<\/sub>). Earlier stages of this upgrade included replacing the original simultaneous (recombinator) injector with a sequential (bounced) injection system of our own design and upgrades to the rare and abundant isotope detection hardware and software.<\/p>\n<p><!--more--><\/p>\n<div id=\"attachment_463\" style=\"width: 310px\" class=\"wp-caption alignright\"><img aria-describedby=\"caption-attachment-463\" loading=\"lazy\" class=\"size-medium wp-image-463\" src=\"https:\/\/www2.whoi.edu\/site\/nosams\/wp-content\/uploads\/sites\/124\/2018\/07\/kvr_475673_thumbnail_475674-300x200.jpg\" alt=\"Karl von Reden taking data\" width=\"300\" height=\"200\" srcset=\"https:\/\/www2.whoi.edu\/site\/nosams\/wp-content\/uploads\/sites\/124\/2018\/07\/kvr_475673_thumbnail_475674-300x200.jpg 300w, https:\/\/www2.whoi.edu\/site\/nosams\/wp-content\/uploads\/sites\/124\/2018\/07\/kvr_475673_thumbnail_475674.jpg 335w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><p id=\"caption-attachment-463\" class=\"wp-caption-text\">Karl von Reden taking data for the first run of the NOSAMS hybrid gas ion source.<\/p><\/div>\n<p>The hybrid sputter gas ion source allows direct measurement of radiocarbon in CO<sub>2<\/sub> without first converting to graphite. A flow of CO<sub>2<\/sub> is streamed across a titanium target cathode under cesium sputtering. After dissociation of CO<sub>2<\/sub>, negatively charged ions are extracted by an acceleration potential.<\/p>\n<p>Initial tests showed that the source produces 10\u00b5A (about 1\/10th the current of graphite targets ) of C<sup>&#8211;<\/sup> with an optimal flow of pure CO<sub>2<\/sub>,. This allows measurement of modern samples to 1% precision in about 30 minutes. Measurement of radiocarbon-free CO<sub>2<\/sub> shows a blank of about 1% of modern carbon. All of these parameters are in the range of typical published performance for other hybrid gas ion sources.<\/p>\n<p>We are now developing inlet systems to interface with the hybrid source. Two approaches are in development, a closed system that allows control of sample flow by adjusting the volume of the inlet using a bellows, and an open split which will introduce sample gas at a set flow defined by the inlet capillary. For large samples, the open split will join systems already developed for the CFAMS microwave gas ion source to the hybrid source. For smaller samples, we are considering inlet systems based on a low pressure, low volume closed system.<\/p>\n<p>In the gas accepting mode, the hybrid source will initially be used for the rapid measurement of samples at lower precision. At the outset we will measure 100-500\u00b5g samples, but we hope to expand this to smaller samples in the 10-100\u00b5g range. We plan to focus initially on samples already converted to CO<sub>2<\/sub>, followed by development of automated hydrolysis (gasbench) for carbonates and an elemental analyser interface for organic samples. Additionally a simple apparatus for rapid measurement of DIC in seawater via acid hydrolysis in a helium carrier stream or REDICS-style CO<sub>2<\/sub> production using a gas-permeable membrane is possible.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>NOSAMS has installed a hybrid gas ion source from NEC as the final stage in upgrading the NOSAMS Tandetron AMS system (USAMS). This source can run either graphite samples or carbon dioxide (CO2). Earlier stages of this upgrade included replacing the original simultaneous (recombinator) injector with a sequential (bounced) injection system of our own design&hellip;<\/p>\n","protected":false},"author":33,"featured_media":454,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"tpl-full-width.php","format":"standard","meta":[],"categories":[5],"tags":[],"_links":{"self":[{"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/posts\/1265"}],"collection":[{"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/users\/33"}],"replies":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/comments?post=1265"}],"version-history":[{"count":3,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/posts\/1265\/revisions"}],"predecessor-version":[{"id":1321,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/posts\/1265\/revisions\/1321"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/media\/454"}],"wp:attachment":[{"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/media?parent=1265"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/categories?post=1265"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www2.whoi.edu\/site\/nosams\/wp-json\/wp\/v2\/tags?post=1265"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}