Improving the detection limit for 182Hf

S. Winkler; L. K. Fifield; S. G. Tims; C. R. Morton

doi:10.1016/j.nimb.2007.01.168

Improving the detection limit for ¹⁸²Hf

S. Winkler^*, L. K. Fifield, S. G. Tims, C. R. Morton

^*Corresponding author for this work

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

12 Citations (Scopus)

Abstract

A nearby supernova would deposit radionuclides on earth. The long-lived radionuclide ¹⁸²Hf (t_1/2 = 8.9 Ma) is one of a number of candidates for an isotopic signature of such an event. Together with ⁶⁰Fe, observation of ¹⁸²Hf would be direct evidence for a supernova site of the r-process. The most suitable site for searching for such a signature would be a deep-sea sediment of slow deposition rate. Measurement of ¹⁸²Hf at the anticipated level requires very effective suppression of the interfering stable isobar ¹⁸²W. Chemical separation and the injection of HfF₅^- allow for suppression by several orders of magnitude, but more is needed for detection of ¹⁸²Hf as a supernova isotope signature. We are currently developing AMS methods for measuring ¹⁸²Hf/¹⁸⁰Hf isotope ratios at the required level using a 15 MV tandem accelerator . Both projectile X-ray emission and the use of a solid passive absorber with a subsequent measurement of the residual energy are being explored. The former suffers from low efficiency, but the latter looks promising.

Original language	English
Pages (from-to)	256-259
Number of pages	4
Journal	Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume	259
Issue number	1
DOIs	https://doi.org/10.1016/j.nimb.2007.01.168
Publication status	Published - Jun 2007

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title = "Improving the detection limit for 182Hf",

abstract = "A nearby supernova would deposit radionuclides on earth. The long-lived radionuclide 182Hf (t1/2 = 8.9 Ma) is one of a number of candidates for an isotopic signature of such an event. Together with 60Fe, observation of 182Hf would be direct evidence for a supernova site of the r-process. The most suitable site for searching for such a signature would be a deep-sea sediment of slow deposition rate. Measurement of 182Hf at the anticipated level requires very effective suppression of the interfering stable isobar 182W. Chemical separation and the injection of HfF5- allow for suppression by several orders of magnitude, but more is needed for detection of 182Hf as a supernova isotope signature. We are currently developing AMS methods for measuring 182Hf/180Hf isotope ratios at the required level using a 15 MV tandem accelerator . Both projectile X-ray emission and the use of a solid passive absorber with a subsequent measurement of the residual energy are being explored. The former suffers from low efficiency, but the latter looks promising.",

keywords = "AMS, Energy-loss, Hf, Supernova",

author = "S. Winkler and Fifield, {L. K.} and Tims, {S. G.} and Morton, {C. R.}",

year = "2007",

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language = "English",

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T1 - Improving the detection limit for 182Hf

AU - Winkler, S.

AU - Fifield, L. K.

AU - Tims, S. G.

AU - Morton, C. R.

PY - 2007/6

Y1 - 2007/6

N2 - A nearby supernova would deposit radionuclides on earth. The long-lived radionuclide 182Hf (t1/2 = 8.9 Ma) is one of a number of candidates for an isotopic signature of such an event. Together with 60Fe, observation of 182Hf would be direct evidence for a supernova site of the r-process. The most suitable site for searching for such a signature would be a deep-sea sediment of slow deposition rate. Measurement of 182Hf at the anticipated level requires very effective suppression of the interfering stable isobar 182W. Chemical separation and the injection of HfF5- allow for suppression by several orders of magnitude, but more is needed for detection of 182Hf as a supernova isotope signature. We are currently developing AMS methods for measuring 182Hf/180Hf isotope ratios at the required level using a 15 MV tandem accelerator . Both projectile X-ray emission and the use of a solid passive absorber with a subsequent measurement of the residual energy are being explored. The former suffers from low efficiency, but the latter looks promising.

AB - A nearby supernova would deposit radionuclides on earth. The long-lived radionuclide 182Hf (t1/2 = 8.9 Ma) is one of a number of candidates for an isotopic signature of such an event. Together with 60Fe, observation of 182Hf would be direct evidence for a supernova site of the r-process. The most suitable site for searching for such a signature would be a deep-sea sediment of slow deposition rate. Measurement of 182Hf at the anticipated level requires very effective suppression of the interfering stable isobar 182W. Chemical separation and the injection of HfF5- allow for suppression by several orders of magnitude, but more is needed for detection of 182Hf as a supernova isotope signature. We are currently developing AMS methods for measuring 182Hf/180Hf isotope ratios at the required level using a 15 MV tandem accelerator . Both projectile X-ray emission and the use of a solid passive absorber with a subsequent measurement of the residual energy are being explored. The former suffers from low efficiency, but the latter looks promising.

KW - AMS

KW - Energy-loss

KW - Hf

KW - Supernova

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

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IS - 1

ER -

Improving the detection limit for ¹⁸²Hf

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