Chlorine-36 in seawater

David C. Argento; John O. Stone; L. Keith Fifield; Stephen G. Tims

doi:10.1016/j.nimb.2009.10.139

Chlorine-36 in seawater

David C. Argento^*, John O. Stone, L. Keith Fifield, Stephen G. Tims

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

23 Citations (Scopus)

Abstract

Natural cosmogenic ³⁶Cl found in seawater originates from spallation of atmospheric ⁴⁰Ar, capture of secondary cosmic-ray neutrons by dissolved ³⁵Cl, and river runoff which contains ³⁶Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of ³⁶Cl compared to the oceanic mixing time should result in a homogenous ³⁶Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated ³⁶Cl concentration. Previous attempts to measure the ³⁶Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the ³⁶Cl/Cl ratio is 0.5 ± 0.3 × 10^-15, in reasonable agreement with calculated contributions from the sources listed above.

Original language	English
Pages (from-to)	1226-1228
Number of pages	3
Journal	Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume	268
Issue number	7-8
DOIs	https://doi.org/10.1016/j.nimb.2009.10.139
Publication status	Published - Apr 2010

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@article{3e05971213cb47b8ab75ceff96511981,

title = "Chlorine-36 in seawater",

abstract = "Natural cosmogenic 36Cl found in seawater originates from spallation of atmospheric 40Ar, capture of secondary cosmic-ray neutrons by dissolved 35Cl, and river runoff which contains 36Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of 36Cl compared to the oceanic mixing time should result in a homogenous 36Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated 36Cl concentration. Previous attempts to measure the 36Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the 36Cl/Cl ratio is 0.5 ± 0.3 × 10-15, in reasonable agreement with calculated contributions from the sources listed above.",

keywords = "AMS, Bomb pulse, Chlorine-36, Cosmogenic isotopes, Cosmogenic nuclide, Direct capture, Neutrons, Seawater",

author = "Argento, {David C.} and Stone, {John O.} and {Keith Fifield}, L. and Tims, {Stephen G.}",

year = "2010",

month = apr,

doi = "10.1016/j.nimb.2009.10.139",

language = "English",

volume = "268",

pages = "1226--1228",

journal = "Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms",

issn = "0168-583X",

publisher = "Elsevier B.V.",

number = "7-8",

}

TY - JOUR

T1 - Chlorine-36 in seawater

AU - Argento, David C.

AU - Stone, John O.

AU - Keith Fifield, L.

AU - Tims, Stephen G.

PY - 2010/4

Y1 - 2010/4

N2 - Natural cosmogenic 36Cl found in seawater originates from spallation of atmospheric 40Ar, capture of secondary cosmic-ray neutrons by dissolved 35Cl, and river runoff which contains 36Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of 36Cl compared to the oceanic mixing time should result in a homogenous 36Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated 36Cl concentration. Previous attempts to measure the 36Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the 36Cl/Cl ratio is 0.5 ± 0.3 × 10-15, in reasonable agreement with calculated contributions from the sources listed above.

AB - Natural cosmogenic 36Cl found in seawater originates from spallation of atmospheric 40Ar, capture of secondary cosmic-ray neutrons by dissolved 35Cl, and river runoff which contains 36Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of 36Cl compared to the oceanic mixing time should result in a homogenous 36Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated 36Cl concentration. Previous attempts to measure the 36Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the 36Cl/Cl ratio is 0.5 ± 0.3 × 10-15, in reasonable agreement with calculated contributions from the sources listed above.

KW - AMS

KW - Bomb pulse

KW - Chlorine-36

KW - Cosmogenic isotopes

KW - Cosmogenic nuclide

KW - Direct capture

KW - Neutrons

KW - Seawater

UR - http://www.scopus.com/inward/record.url?scp=77949903679&partnerID=8YFLogxK

U2 - 10.1016/j.nimb.2009.10.139

DO - 10.1016/j.nimb.2009.10.139

M3 - Article

SN - 0168-583X

VL - 268

SP - 1226

EP - 1228

JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

IS - 7-8

ER -

Chlorine-36 in seawater

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