Liddick S N, Spyrou A, Crider B P, Naqvi F, Larsen A C, Guttormsen M, Mumpower M, Surman R, Perdikakis G, Bleuel D L, Couture A, Crespo Campo L, Dombos A C, Lewis R, Mosby S, Nikas S, Prokop C J, Renstrom T, Rubio B, Siem S, Quinn S J
National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, East Lansing, Michigan 48824, USA.
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Phys Rev Lett. 2016 Jun 17;116(24):242502. doi: 10.1103/PhysRevLett.116.242502. Epub 2016 Jun 16.
Nuclear reactions where an exotic nucleus captures a neutron are critical for a wide variety of applications, from energy production and national security, to astrophysical processes, and nucleosynthesis. Neutron capture rates are well constrained near stable isotopes where experimental data are available; however, moving far from the valley of stability, uncertainties grow by orders of magnitude. This is due to the complete lack of experimental constraints, as the direct measurement of a neutron-capture reaction on a short-lived nucleus is extremely challenging. Here, we report on the first experimental extraction of a neutron capture reaction rate on ^{69}Ni, a nucleus that is five neutrons away from the last stable isotope of Ni. The implications of this measurement on nucleosynthesis around mass 70 are discussed, and the impact of similar future measurements on the understanding of the origin of the heavy elements in the cosmos is presented.
奇异原子核捕获中子的核反应对于从能源生产、国家安全到天体物理过程以及核合成等各种各样的应用至关重要。在有实验数据的稳定同位素附近，中子俘获率受到很好的限制；然而，远离稳定谷时，不确定性会增加几个数量级。这是由于完全缺乏实验约束，因为对短寿命原子核上的中子俘获反应进行直接测量极具挑战性。在此，我们报告了对(^{69}Ni)上中子俘获反应率的首次实验提取，(^{69}Ni)是一个距离镍的最后一个稳定同位素相差五个中子的原子核。讨论了该测量对质量数约为70附近核合成的影响，并展示了未来类似测量对理解宇宙中重元素起源的影响。
