Relative proton and gamma widths of astrophysically important states in S-30 studied in the beta-delayed decay of Ar-31
Artikel i vetenskaplig tidskrift, 2013

Resonances just above the proton threshold in S-30 affect the P-29(p, gamma)S-30 reaction under astrophysical conditions. The (p,gamma)-reaction rate is currently determined indirectly and depends on the properties of the relevant resonances. We present here a method for finding the ratio between the proton and gamma partial widths of resonances in S-30. The widths are determined from the beta 2p- and beta p gamma-decay of Ar-31, which is produced at the ISOLDE radioactive ion beam facility at the European research organization CERN. Experimental limits on the ratio between the proton and gamma partial widths for astrophysical relevant levels in S-30 have been found for the first time. A level at 4689.2(24) keV is identified in the gamma spectrum, and an upper limit on the Gamma(p)/ Gamma gamma ratio of 0.26 (95% C.L.) is found. In the two-proton spectrum two levels at 5227(3) keV and 5847(4) keV are identified. These levels were previously seen to gamma decay and upper limits on the Gamma(gamma)/Gamma(p) ratio of 0.5 and 9, respectively, (95% C.L.) are found, where the latter differs from previous calculations.

Författare

G. T. Koldste

B. Blank

M. J. G. Borge

J. A. Briz

M. Carmona-Gallardo

L. M. Fraile

H. O. U. Fynbo

J. Giovinazzo

J. G. Johansen

A. Jokinen

Björn Jonson

Chalmers, Teknisk fysik, Subatomär fysik

T. Kurturkian-Nieto

J. H. Kusk

Thomas Nilsson

Chalmers, Teknisk fysik, Subatomär fysik

A. Perea

V. Pesudo

E. Picado

K. Riisager

A. Saastamoinen

Olof Tengblad

J. C. Thomas

J. Van de Walle

Physical Review C - Nuclear Physics

0556-2813 (ISSN) 1089-490X (eISSN)

Vol. 87 5

Ämneskategorier

Subatomär fysik

Fysik

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1103/PhysRevC.87.055808