Decay Rate of Beryllium-7 in Different Environments

Abstract

The News of the Week article “Tweaking the clock of radioactive decay” (29 Oct., p. [882][1]) by Richard A. Kerr focuses on the finding by Chih-An Huh ([1][2]), published in Earth and Planetary Science Letters , that beryllium-7 decays at a different rate depending on what form it is in (hydrated ion, hydroxide, or oxide). However, relatively large variations in the decay rate of beryllium-7 in different environments had already been reported before Huh published his results. About 4 months before Huh's publication, we published an article ([2][3]) reporting that the decay rate of beryllium-7 implanted in gold is slower than when it is implanted in Al2O3 by a relatively large amount (0.72%). This result and many others have been understood using the linear muffin-tin orbital (LMTO) method and Hartree's calculations, and the implications of these results in different fields have been discussed ([2][3]). Before our work, W. K. Hensley et al. ([3][4]) applied a high pressure of up to 270 kilobars to 7BeO and found that the decay rate increased by 0.59%. In his article, Chih-An Huh reports that the decay rate of beryllium-7 is about 1.0% faster when the beryllium is in the chemical form Be2+(OH2)4, as compared with BeO. Earlier, however, H. W. Johlige et al. ([4][5]) also measured the difference between the decay rates of beryllium-7 in the same matrices and found it to be (0.0374 _ 0.0077)% faster as compared with BeO. They also measured the differences of beryllium-7 decay rates in many other chemical forms and detected only tiny variations of the order of 0.1% ([4][5]). Such differing results have yet to be discussed. 1. [↵][6] Chih-An Huh, Earth Planet. Sci. Lett. 171, 325 (1999). 2. [↵][7]1. A. Ray 2. et al. , Phys. Lett. B 455, 69 (1999). [OpenUrl][8] 3. [↵][9]1. W. K. Hensley, 2. W. A. Basset, 3. J. R. Huizenga , Science 181, 1164 (1973). [OpenUrl][10][Abstract/FREE Full Text][11] 4. [↵][12]1. H. W. Johlige, 2. D. C. Aumann, 3. H. J. Born , Phys. Rev. C2, 1616 (1970). [OpenUrl][13] [1]: /lookup/doi/10.1126/science.286.5441.882 [2]: #ref-1 [3]: #ref-2 [4]: #ref-3 [5]: #ref-4 [6]: #xref-ref-1-1 View reference 1 in text [7]: #xref-ref-2-1 View reference 2 in text [8]: {openurl}?query=rft.jtitle%253DPhys.%2BLett.%2BB%26rft.volume%253D455%26rft.spage%253D69%26rft.atitle%253DPHYS%2BLETT%2BB%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [9]: #xref-ref-3-1 View reference 3 in text [10]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.issn%253D0036-8075%26rft.aulast%253DHensley%26rft.auinit1%253DW.%2BK.%26rft.volume%253D181%26rft.issue%253D4105%26rft.spage%253D1164%26rft.epage%253D1165%26rft.atitle%253DPressure%2BDependence%2Bof%2Bthe%2BRadioactive%2BDecay%2BConstant%2Bof%2BBeryllium-7%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.181.4105.1164%26rft_id%253Dinfo%253Apmid%252F17744291%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [11]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIxODEvNDEwNS8xMTY0IjtzOjQ6ImF0b20iO3M6MjU6Ii9zY2kvMjg3LzU0NTYvMTIwMy45LmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ== [12]: #xref-ref-4-1 View reference 4 in text [13]: {openurl}?query=rft.jtitle%253DPhys.%2BRev.%26rft.volume%253DC2%26rft.spage%253D1616%26rft.atitle%253DPHYS%2BREV%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx