New {sup 34}Cl proton-threshold states and the thermonuclear {sup 33}S(p,{gamma}){sup 34}Cl rate in ONe novae

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.80.015802· OSTI ID:21290019

Parikh, A; Faestermann, T; Kruecken, R; Behrens, T; Bildstein, V; Bishop, S; Eppinger, K; Herlitzius, C; Hinke, C; Schlarb, M; Seiler, D; Wimmer, K ^[1]; Hertenberger, R; Wirth, H -F ^[2]; Schafstadler, D ^[1]

---

1. Physik Department E12, Technische Universitaet Muenchen, D-85748 Garching (Germany)
2. Maier-Leibnitz-Laboratorium der Muenchner Universitaeten (MLL), D-85748 Garching (Germany)

Analysis of presolar grains in primitive meteorites has shown isotopic ratios largely characteristic of the conditions thought to prevail in various astrophysical environments. A possible indicator for a grain of ONe nova origin is a large {sup 33}S abundance: nucleosynthesis calculations predict as much as 150 times the solar abundance of {sup 33}S in the ejecta of nova explosions on massive ONe white dwarfs. This overproduction factor may, however, vary by factors of at least 0.01-3 because of uncertainties of several orders of magnitude in the {sup 33}S(p,{gamma}){sup 34}Cl reaction rate at nova peak temperatures (T{sub peak}{approx}0.1-0.4 GK). These uncertainties arise due to the lack of nuclear physics information for states within {approx}600 keV of the {sup 33}S+p threshold in {sup 34}Cl (S{sub p}({sup 34}Cl) = 5143 keV). To better constrain this rate we have measured, for the first time, the {sup 34}S({sup 3}He,t){sup 34}Cl reaction over the region E{sub x}({sup 34}Cl) = 4.9-6 MeV. We confirm previous states and find 15 new states in this energy region. New {sup 33}S(p,{gamma}){sup 34}Cl resonances at E{sub R}=281(2), 301(2), and 342(2) keV may dominate this rate at relevant nova temperatures. Our results could affect predictions of sulphur isotopic ratios in nova ejecta (e.g., {sup 32}S/{sup 33}S) that may be used as diagnostic tools for the nova paternity of grains.

• OSTI ID: 21290019
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 1 Vol. 80; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASTROPHYSICS
CHLORINE 34
EXPLOSIONS
FORECASTING
GAMMA DECAY
HELIUM 3
ISOTOPE RATIO
METEORITES
MEV RANGE 01-10
NOVAE
NUCLEAR PHYSICS
NUCLEOSYNTHESIS
PROTONS
REACTION KINETICS
RESONANCE
SULFUR
SULFUR 33 TARGET
WHITE DWARF STARS