24 Si and the 23 Al p γ 24 Si R eaction in T ype I X ray B ursts How can we measure capture crosssections for 23 Alpγ 24 Si without directly measuring in stellar environments ID: 778609
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Slide1
One-proton Breakup of 24Si and the 23Al( p, γ )24Si Reaction in Type I X-ray Bursts
How can we measure capture cross-sections for 23Al(p,γ)24Si without directly measuring in stellar environments?
When binary star systems consist of a neutron star and a main sequence star (similar to our own sun), the neutron star accretes material and causes a nuclear fusion to begin again on its surface.
Burst occurs at ~1-2 GK ~ 172 KeV/nucleon
Wave function of Proton
The proton only needs to overcome the coulomb potential of the
24
Si nucleus
U ≈ 6
M
eV
Slide2Inverse kinematics of the 24Si BreakupWe can consider |24Si> = |23Al>⊗|p> with a binding energy of 3.3 MeV
24
Si
P
23Al
Using the cross section of the breakup reaction we can deduce the cross-section for the proton capture reaction via the Asymptotic Normalization Coefficient, which defines the height of the tail of the coulomb potential
Using this coefficient we can measure, we can take the ration of the measured cross section with the theoretical cross section for the interaction with the coulomb potential to determine the astrophysical cross section
Slide3SummaryAstrophysical energies are too low for us to determine proton capture reactions in stellar environmentsCross sections for tunneling are too low in lab environmentMeasurements of inverse kinematics allows us to investigate these reactions through breakup reactions by giving a feasible cross section value A. Banu et al., Phys.Rev. C 86, 015806 (2012), Erratum Phys.Rev. C 86, 039901 (2012)V.Kroha et al., Czech.J.Phys. 51, 471 (2001).