Fusion hindrance for a positive-q-value system (24)Mg+(30)Si

Area of Science:

• Nuclear Physics
• Astrophysics
• Stellar Evolution

Background:

• Understanding nuclear fusion reactions is crucial for stellar evolution models.
• Previous studies on fusion excitation functions have provided valuable data, but gaps remain at lower energies for specific systems.

Purpose of the Study:

• To extend measurements of the excitation function for the fusion of 24Mg + 30Si towards lower energies.
• To investigate the significance and systematics of the S-factor maximum in positive Q-value fusion systems.

Main Methods:

• Experimental measurement of the excitation function for 24Mg + 30Si fusion.
• Analysis of S-factor behavior at lower energies.

Main Results:

• The fusion excitation function for 24Mg + 30Si was extended to lower energies.
• A pronounced S-factor maximum was observed in this positive Q-value system, more so than in previously studied systems.
• The findings suggest a significant impact on extrapolated cross sections and reaction rates.

Conclusions:

• The observed S-factor maximum provides critical data for nuclear astrophysics.
• Results influence models of carbon and oxygen burning stages in stars.
• This study enhances our understanding of stellar nucleosynthesis and evolution history.