Half-Life Measurement for the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">rp</mi></math></span>-Process Waiting Point Nuclide <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>Z</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>80</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow><mi>r</mi></math></span>

J. J. Ressler; A. Piechaczek; W. B. Walters; A. Aprahamian; M. Wiescher; J. C. Batchelder; C. R. Bingham; D. S. Brenner; T. N. Ginter; C. J. Gross; R. Grzywacz; D. Kulp; B. MacDonald; W. Reviol; J. Rikovska; K. Rykaczewski; J. A. Winger; E. F. Zganjar

doi:10.1103/PhysRevLett.84.2104

Half-Life Measurement for the $rp$ -Process Waiting Point Nuclide ${}^{80}Z r$

J. J. Ressler, A. Piechaczek, W. B. Walters, A. Aprahamian, M. Wiescher, J. C. Batchelder, C. R. Bingham, D. S. Brenner, T. N. Ginter, C. J. Gross, R. Grzywacz, D. Kulp, B. MacDonald, W. Reviol, J. Rikovska, K. Rykaczewski, J. A. Winger, and E. F. Zganjar

Phys. Rev. Lett. 84, 2104 – Published 6 March 2000

Abstract

X-ray bursts have been suggested as a possible site for the astrophysical $rp$ -process. The time scale for the process is governed by $β$ -decay half-lives of several even-even $N = Z$ waiting point nuclei, in particular, $N = Z = 40$ $^{80} Zr$ . A $4.1 ({+ 0.8} {- 0.6}) - s$ $β^{+} / EC$ half-life for $^{80} Zr$ was determined by observing delayed 84-keV $γ$ rays depopulating a $T_{1 / 2} = 4 - μ s$ isomer at 312 keV in the daughter $^{80} Y$ . As this half-life is lower than many previously predicted values, the calculated excessive production of $A = 80$ nuclides in astrophysical x-ray burst scenarios is reduced, and less extreme conditions are necessary for the production of heavier nuclides.

Received 6 July 1999

DOI:https://doi.org/10.1103/PhysRevLett.84.2104

Authors & Affiliations

J. J. Ressler¹, A. Piechaczek², W. B. Walters¹, A. Aprahamian³, M. Wiescher³, J. C. Batchelder⁴, C. R. Bingham^5,6, D. S. Brenner⁷, T. N. Ginter⁸, C. J. Gross^4,6, R. Grzywacz⁵, D. Kulp⁹, B. MacDonald⁹, W. Reviol⁵, J. Rikovska¹, K. Rykaczewski^6,10, J. A. Winger¹¹, and E. F. Zganjar²

¹Department of Chemistry, University of Maryland, College Park, Maryland 20742
²Department of Physics, Louisiana State University, Baton Rouge, Louisiana 70803
³Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556
⁴UNIRIB, Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831
⁵Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996
⁶Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
⁷Department of Chemistry, Clark University, Worcester, Massachusetts 01610
⁸Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235
⁹School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332
¹⁰Warsaw University, PL 00681, Warsaw, Poland
¹¹Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762