Experimental Research on the Key Reaction of Stellar Helium Burning: ¹²C(α, γ)¹⁶O

The ¹²C(α, γ)¹⁶O reaction is one of the most important reactions in nuclear astrophysics. It greatly influences the ratio of the abundances for the carbon and oxygen created at the end of the helium burning by competing with the triple-α process. It is of great significance for understanding both stellar and biological evolution, as well as for studying black hole gaps. It is called the Holy Grail reaction in nuclear astrophysics. In this article, the current research status of this reaction and future plans were introduced. There are several indirect methods to measure this reaction, such as elastic scattering, β-delayed α decay of ¹⁶N, inverse reactions and α transfer reactions. In recent years, there were also some direct measurement experiments. However, these studies couldn’t make the measurement entering inside the Gamow Window. There are also differences between different indirect measurement results. The uncertainty of this reaction is still much larger than the critical value of 10%, which is required by the nuclear astrophysics calculation. Therefore, the measurement of this reaction remains a focus of attention in nuclear astrophysics. The RNB group in China Institute of Atomic Energy used the (¹¹B, ⁷Li) transfer reaction to study the ¹²C(α, γ)¹⁶O reaction and are working on the direct experiment in Jinping underground nuclear astrophysics laboratory. The lowest energy experiment has been finished and the measurement for lower energy will be performed in the future.