19F是氟元素唯一稳定同位素，AGB星是其可能的合成场所，AGB星相关天文学观测中已经发现了其丰度远大于太阳系值。19F合成相关核反应率是天体网络计算中的重要输入量，其中19F(p,a)16O反应是19F主要的破坏反应。19F(p,ag)16O反应道在天体物理感兴趣的低能区受质子阈附近1+态共振影响较大，且直接反应测量难以完全覆盖相应能区，也无法测到该共振峰的峰值，只能由间接测量提供共振参数。目前仅有两项19F(3He,d)20Ne测量结果，且二者的共振能量有36keV差异，给19F(p,ag)16O反应道低能外推带来很大的不确定性。本项目拟在北京HI-13串列加速器Q3D磁谱仪终端上实现19F(7Li,6He)20Ne反应布居20Ne相应能级的首次实验，旨在对20Ne能级能量和质子宽度进行精确测量，消除之前实验的分歧，从而得到可靠的19F(p,a)16O反应率，并最终揭示其天体物理意义。

19F is the only stable isotope of fluorine element. AGB star is one of the possible sites of 19F synthesis. Astronomical observation related to AGB stars shows that the 19F abundance is much larger than that in the solar system. The nuclear reaction rates relevant to 19F synthesis are important inputs in astrophysical network calculations. Among them 19F(p,a)16O is one of the major destruction reaction. The 19F(p,ag)16O reaction channel can be influenced by a 1+ resonance near the proton threshold in the low-energy region of astrophysical interest. Resonance parameters deduced from indirect experiments are absolutely necessary because direct measurement can hardly cover neither the entire region of astrophysical interest nor the peak of this resonance(only about 11keV around the proton threshold). As for this important aimed resonance, the resonance energy values measured from the only two 19F(3He,d)20Ne experiments(one is from a PhD thesis work) show difference of 36keV, which lead to great uncertainty in the 19F(p,ag)16O low-energy S-factor extrapolation. In the present project, we will carry out the first experiment of 19F(7Li,6He)20Ne reaction populating the 20Ne 1+ state. The energy and proton width of this state will be measured precisely. The 19F(p,a)16O reaction rate and the astrophysical implications will be evaluated based on a firmer experimental ground.