Progress in AMS measurement of natural 32 Si for glacier ice dating
AMS measurement of 32Si can allow for ice core dating over the last thousand years. Technique developments are reported. Necessary negative-ion yields of 20-30% can now be consistently achieved, and permit an overall efficiency from ice sample to detector of ∼1%. A 30Si-spike technique has overcome...
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ftanucanberra:oai:digitalcollections.anu.edu.au:1885/56970 2023-05-15T13:36:32+02:00 Progress in AMS measurement of natural 32 Si for glacier ice dating Morgenstern, Uwe Fifield, L Keith Tims, Stephen Ditchburn, Robert G. 2015-12-10T22:38:59Z http://hdl.handle.net/1885/56970 unknown Elsevier 0168-583X http://hdl.handle.net/1885/56970 Nuclear Instruments and Methods in Physics Research: Section B Journal article 2015 ftanucanberra 2015-12-28T23:29:42Z AMS measurement of 32Si can allow for ice core dating over the last thousand years. Technique developments are reported. Necessary negative-ion yields of 20-30% can now be consistently achieved, and permit an overall efficiency from ice sample to detector of ∼1%. A 30Si-spike technique has overcome the problem of extremely low intrinsic silicon concentration, with the added benefit of allowing determination of ppb-level silicon via isotope dilution. Improvements have also been made to the ionization detector in the gas-filled magnet that separates the accelerated 32Si ions from the intense flux of 32S ions. Preliminary 32Si AMS results of snow and ice samples from Mt. Cook National Park, New Zealand, are reproducible, and with 32Si concentrations 1.2-7.2 mBq/m3 comparable to results from mid-latitude snow samples measured previously via the radiometric technique, demonstrating the feasibility of the method. With these developments, the potential of 32Si as ice core dating tool is close to being realized, and attempts to determine chronologies for both alpine and Antarctic glaciers are underway. Article in Journal/Newspaper Antarc* Antarctic ice core Australian National University: ANU Digital Collections Antarctic New Zealand |
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Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
description |
AMS measurement of 32Si can allow for ice core dating over the last thousand years. Technique developments are reported. Necessary negative-ion yields of 20-30% can now be consistently achieved, and permit an overall efficiency from ice sample to detector of ∼1%. A 30Si-spike technique has overcome the problem of extremely low intrinsic silicon concentration, with the added benefit of allowing determination of ppb-level silicon via isotope dilution. Improvements have also been made to the ionization detector in the gas-filled magnet that separates the accelerated 32Si ions from the intense flux of 32S ions. Preliminary 32Si AMS results of snow and ice samples from Mt. Cook National Park, New Zealand, are reproducible, and with 32Si concentrations 1.2-7.2 mBq/m3 comparable to results from mid-latitude snow samples measured previously via the radiometric technique, demonstrating the feasibility of the method. With these developments, the potential of 32Si as ice core dating tool is close to being realized, and attempts to determine chronologies for both alpine and Antarctic glaciers are underway. |
format |
Article in Journal/Newspaper |
author |
Morgenstern, Uwe Fifield, L Keith Tims, Stephen Ditchburn, Robert G. |
spellingShingle |
Morgenstern, Uwe Fifield, L Keith Tims, Stephen Ditchburn, Robert G. Progress in AMS measurement of natural 32 Si for glacier ice dating |
author_facet |
Morgenstern, Uwe Fifield, L Keith Tims, Stephen Ditchburn, Robert G. |
author_sort |
Morgenstern, Uwe |
title |
Progress in AMS measurement of natural 32 Si for glacier ice dating |
title_short |
Progress in AMS measurement of natural 32 Si for glacier ice dating |
title_full |
Progress in AMS measurement of natural 32 Si for glacier ice dating |
title_fullStr |
Progress in AMS measurement of natural 32 Si for glacier ice dating |
title_full_unstemmed |
Progress in AMS measurement of natural 32 Si for glacier ice dating |
title_sort |
progress in ams measurement of natural 32 si for glacier ice dating |
publisher |
Elsevier |
publishDate |
2015 |
url |
http://hdl.handle.net/1885/56970 |
geographic |
Antarctic New Zealand |
geographic_facet |
Antarctic New Zealand |
genre |
Antarc* Antarctic ice core |
genre_facet |
Antarc* Antarctic ice core |
op_source |
Nuclear Instruments and Methods in Physics Research: Section B |
op_relation |
0168-583X http://hdl.handle.net/1885/56970 |
_version_ |
1766080187862089728 |