Home / Colloquium / The 22Ne(α,n)/(α,γ) branching ratio: Payoff after a long and winding road of research efforts
March 30, 20215:00 pm – 6:00 pm (CDT)
The 22Ne(α,n)/(α,γ) branching ratio: Payoff after a long and winding road of research efforts
Speaker:
Shuya Ota (Texas A&M University)
Host:
Dan Melconian
Event Details
Payoff after a long and winding road of research efforts
The slow neutron capture process (s-process) in AGB stars and
massive stars forms about half of the elements heavier than Fe in the
solar system. The impact of this process on chemical evolution in the
Galaxy is thus tremendous. One of the keys to further constraining the
process is determining notoriously hard-to-measure cross section of the
22Ne+α→25Mg+n reaction [22Ne(α,n)], which is the main source of uncertainties in predicted s-process abundances. Experimental difficulties due to the extremely small cross sections were circumvented in the present study by a new technique to measure the 22Ne(α,n)/(α,γ) branching ratio using a magnetic spectrograph at the TAMU Cyclotron Institute. In this talk, I will show how the expected s-process
abundances, especially in core-collapse supernovae, are drastically
changed due to the reduced – and now well-constrained – cross sections
from our measurements. Finally, I will discuss future experiments to
understand the origin of chemical elements using radioactive ion beams.