Accelerator mass spectrometry

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Accelerator Mass Spectrometry
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Accelerator mass spectrometry
Organic molecules
Biomolecules
Other techniques
RelatedParticle accelerator

Accelerator mass spectrometry (AMS) is a form of

isotopic abundance
ranges from 10−12 to 10−18.)

AMS can outperform the competing technique of decay counting for all isotopes where the half-life is long enough.[2] Other advantages of AMS include its short measuring time as well as its ability to detect atoms in extremely small samples.[3]

Method

Generally, negative

velocity selectors, which utilizes both electric fields and magnetic fields. After this stage, no background is left, unless a stable
(atomic) isobar forming negative ions exists (e.g. 36S if measuring 36Cl), which is not suppressed at all by the setup described so far. Thanks to the high energy of the ions, these can be separated by methods borrowed from nuclear physics, like degrader foils and gas-filled magnets. Individual ions are finally detected by single-ion counting (with silicon surface-barrier detectors, ionization chambers, and/or time-of-flight telescopes). Thanks to the high energy of the ions, these detectors can provide additional identification of background isobars by nuclear-charge determination.

Generalizations

Schematic of an accelerator mass spectrometer[6]

The above is just one example. There are other ways in which AMS is achieved; however, they all work based on improving mass selectivity and specificity by creating high kinetic energies before molecule destruction by stripping, followed by single-ion counting.

History

radioisotope date experimentally obtained using tritium. His paper was the direct inspiration for other groups using cyclotrons (G. Raisbeck and F. Yiou, in France) and tandem linear accelerators (D. Nelson, R. Korteling, W. Stott at McMaster). K. Purser and colleagues also published the successful detection of radiocarbon using their tandem at Rochester. Soon afterwards the Berkeley and French teams reported the successful detection of 10Be, an isotope widely used in geology. Soon the accelerator technique, since it was more sensitive by a factor of about 1,000, virtually supplanted the older "decay counting" methods for these and other radioisotopes. In 1982, AMS labs began processing archaeological samples for radiocarbon dating [8]

Applications

There are many applications for AMS throughout a variety of disciplines. AMS is most often employed to determine the concentration of

3H, 14C, 36Cl, and 129I
are used as hydrological tracers.

Accelerator mass spectrometry is widely used in biomedical research.

41Ca
has been used to measure bone resorption in postmenopausal women.

See also

References

  1. ISBN 978-0-86542-684-9.[dead link
    ]
  2. PMID 16134128
    .
  3. PMID 18470926
    .
  4. doi:10.1146/annurev.ns.30.120180.002253
    .
  5. doi:10.1002/(SICI)1098-2787(1998)17:2<97::AID-MAS2>3.0.CO;2-J
    .
  6. PMID 19534792
    .
  7. S2CID 21813292
    .
  8. S2CID 91488734
    . Retrieved July 12, 2022.
  9. ^ Morlan, Richard. "Radiocarbon Dating Principles". Canadian Archaeology. Canadian Archaeological Radiocarbon Database. Retrieved July 12, 2022.
  10. S2CID 247396585
    .
  11. PMID 16401518
    .
  12. PMID 16528913
    .
  13. PMID 15706618
    .

Bibliography

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