Monday, September 30, 2013
The 6Li(22Ne,26Mg)d α-transfer experiment for the study of low-energy resonances in 22Ne(α,γ)26Mg
Shuya Ota (Japan Atomic Energy Agency, Tokai, Ibaraki, Japan)
The slow neutron-capture process (s-process) is responsible for creating about half of the elements heavier than iron that are observed in the solar system. The 22Ne(α,n)25Mg (α-particle-capture on 22Ne and neutron emission) reaction is expected to be an important source of neutrons for the s-process and the reaction rate largely influences the synthesis of nuclides during the s-process.
A variety of attempts to experimentally determine the reaction rate in the energy range of 400-1000 keV α-particles in laboratory system, corresponding to the s-process temperatures in the stars (0.2-0.3 GK), has been made. These include direct 22Ne(α,n)25Mg measurements and indirect measurements via 26Mg(γ,n)25Mg, 25Mg(n,γ)26Mg, 26Mg(γ,γ')26Mg, 26Mg(p,p'γ)26Mg, and 22Ne(6Li,d)26Mg α-transfer reactions. However, ambiguities of important low-energy resonances in 26Mg produced by α + 22Ne have remained the longstanding problem.
To solve the problem, we studied the 6Li(22Ne,26Mg)d α-transfer experiment. The experiments were performed using a 22Ne beam from JAEA (Japan Atomic Energy Agency)-Tokai 20 MV Tandem accelerator. The results showed successful coincidences of Mg and deuteron ions and the obtained reaction yield was in good agreement with the expected value [1, 2]. In the present seminar, our experimental techniques will be introduced and the results from the experiment will be discussed.
 S. Ota et al., Proceedings of Science (NIC XII) 221 (2012).
 S. Ota et al., European Physical Journal web of conference (INPC 2013, submitted)