Detection of 135Cs by accelerator mass spectrometry. (15th January 2015)

• Record Type: Journal Article
• Authors: MacDonald, C.; Charles, C. R. J.; Cornett, R. J.; Zhao, X. L.; Kieser, W. E.; Litherland, A. E.
• Is Part Of: Rapid communications in mass spectrometry. Volume 29:Number 1(2015)
• Page Start: 115
• Page End: 118
• Publication Date: 2015-01-15
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.7083
• Languages: English
• ISSNs: 0951-4198

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="rcm7083-sec-0001" sec-type="section"> <title>RATIONALE</title> <p>The ability to measure both <sup>135</sup>Cs and <sup>137</sup>Cs can provide an estimate of the age and source of Cs isotopes in an environmental sample. Accelerator mass spectrometry (AMS) consistently reports lower abundance sensitivities than other techniques and, with the addition of an on‐line reaction cell, simpler isobaric suppression. Therefore, an AMS methodology was developed to measure Cs isotopes using Cs<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh2jcbqbnw" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" overflow="scroll" altimg="urn:x-wiley:09514198:media:rcm7083:rcm7083-math-0001" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi mathvariant="normal">F</mml:mi><mml:mn>2</mml:mn><mml:mo form="prefix">−</mml:mo></mml:msubsup></mml:math></alternatives></inline-formula> as the initial anion.</p> </sec> <sec id="rcm7083-sec-0002" sec-type="section"> <title>METHODS</title> <p>The ion beam is passed through the Isobar Separator for Anions (ISA) where it is captured by radiofrequency quadrupoles in a gas cell before injection into the tandem accelerator. In the ISA, the beam reacts with O<sub>2</sub> gas, selectively removing the Ba<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh2jcbqbq0" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" overflow="scroll" altimg="urn:x-wiley:09514198:media:rcm7083:rcm7083-math-0002" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi mathvariant="normal">F</mml:mi><mml:mn>2</mml:mn><mml:mo form="prefix">−</mml:mo></mml:msubsup></mml:math></alternatives></inline-formula> and leaving the Cs analyte to be reaccelerated and sent through the remainder of the AMS system.</p> </sec> <sec id="rcm7083-sec-0003" sec-type="section"> <title>RESULTS</title> <p>The Ba<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh2jcbqbs3" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" overflow="scroll" altimg="urn:x-wiley:09514198:media:rcm7083:rcm7083-math-0003" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi mathvariant="normal">F</mml:mi><mml:mn>2</mml:mn><mml:mo form="prefix">−</mml:mo></mml:msubsup></mml:math></alternatives></inline-formula> signal was attenuated by a factor of 10<sup>5</sup> in the ISA while 25% of the original Cs<inline-formula><alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgh2jcbqc5p" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" overflow="scroll" altimg="urn:x-wiley:09514198:media:rcm7083:rcm7083-math-0004" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi mathvariant="normal">F</mml:mi><mml:mn>2</mml:mn><mml:mo form="prefix">−</mml:mo></mml:msubsup></mml:math></alternatives></inline-formula> current was transmitted into the accelerator. <sup>135</sup>Cs was measured without any interference from <sup>133</sup>Cs to an abundance sensitivity of 1.3 × 10<sup>–10</sup>. The abundances of four stable Ba isotopes (masses 133, 134, 135 and 137) were measured and no isotope‐dependent bias was detected using the ISA in vacuum.</p> </sec> <sec id="rcm7083-sec-0004" sec-type="section"> <title>CONCLUSIONS</title> <p>The results demonstrate the feasibility of measuring long‐lived Cs isotopes without Ba interference by AMS with on‐line isobar separation and the ability to use shorter lived Cs isotopes for yield tracing. Copyright © 2014 John Wiley & Sons, Ltd.</p> </sec> </abstract>