The 40Ca(alpha,gamma)44Ti reaction in the energy regime of supernova nucleosynthesis

Abstract

The 44Ti(t1/2 = 59 y) nuclide, an important signature of supernova nucleosynthesis, has recently been observed as live radioactivity by gamma-ray astronomy from the Cas A remnant. We investigate in the laboratory the major 44Ti production reaction, 40Ca(alpha,gamma)44Ti (E_cm = 0.6-1.2 MeV/u), by direct off- line counting of 44Ti nuclei. The yield, significantly higher than inferred from previous experiments, is analyzed in terms of a statistical model using microscopic nuclear inputs. The associated stellar rate has important astrophysical consequences, increasing the calculated supernova 44Ti yield by a factor ~2 over previous estimates and bringing it closer to Cas A observations.

To be published in Phys. Rev. lett., 4 pages, 1 table, 2 figures

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Cited by in corpus (17)

• Presupernova evolution and explosive nucleosynthesis of rotating massive stars in the metallicity range -3 <=[Fe/H]<= 0
• Constraining the astrophysical origin of the p-nuclei through nuclear physics and meteoritic data
• The 44Ti-powered spectrum of SN 1987A
• The signature of 44Ti in Cassiopeia A revealed by IBIS/ISGRI on INTEGRAL
• The activation method for cross section measurements in nuclear astrophysics
• Cross sections of $\alpha$-induced reactions for targets with masses $A\approx 20-50$ at low energies
• The resonance triplet at E_alpha = 4.5 MeV in the 40Ca(alpha,gamma)44Ti reaction
• Measurement of the 33S(α,p)36Cl cross section: Implications for production of 36Cl in the early Solar System
• Primary gamma-ray spectra in 44Ti of astrophysical interest
• Density profiles near nuclear surface of ${}^{44,52}$Ti: An indication of $\alpha$ clustering
• Strength of the $E_{\text{p}}$=1.842 MeV resonance in the ${}^{40}$Ca(p,$\gamma$)${}^{41}$Sc reaction revisited
• Re-measurement of the ${}^{33}$S($\alpha$,p)${}^{36}$Cl cross section for Early solar system enrichment
• Role of Tensor Interaction as Salvation of Cluster Structure in ${}^{44}$Ti
• Measurement of the stellar ${}^{58}$Ni$(n,\gamma {)}^{59}$Ni cross section with AMS
• Alpha-decay from ${}^{44}$Ti: A study of the microscopic clusterization
• Astronomy with Radioactivities: Chapter 9, Nuclear Reactions
• Massive stars as thermonuclear reactors and their explosions following core collapse