摘要:
14O （
α，p）
17F是天体X射线暴中重要的突破反应。本工作通过厚靶方法测量其逆反应
1H （
17F，
α）
14O的反应截面来研究这一关键反应。本实验工作是在日本东京大学原子核科学研究中心（CNS）的低能次级束流线（CRIB）上完成的，后续的扣除本底实验是在兰州放射性束流线（RIBLL1）上完成的。CRIB实验是通过
2H （
16O，n）
17F转移反应产生
17F次级束，经过CRIB分离提纯之后，利用该次级束轰击氢气靶。在氢气靶后布置了三套望远镜探测器系统，用以探测不同实验角度的反冲
α粒子，在数据处理的过程中经过动力学重构后得到了
1H （
17F，
α）
14O反应在质心系能区
Ec.m.=2.7~3.4 MeV的反应截面。实验结果在3 MeV以上的高能区与前人的薄靶实验数据是一致的，在低能区本工作获得了新的实验数据，倾向于支持干涉相消的理论预言结果。
The
14O(
α, p)
17F reaction is one of the important breakout reactions in type I X-ray burst. This work reported a new cross section measurement of its reverse reaction of
1H(
17F,
α)
14O. The experiment was performed using the CNS radioactive ion beam separator (CRIB), located at the Center for Nuclear Study (CNS), the University of Tokyo. The sequent background measurement was carried out at Radioactive Beam Line in Lanzhou (RIBLL1).
17F beam was produced via the transfer reaction of
2H(
16O, n)
17F, subsequently separated and purified by CRIB and bombarded a thick hydrogen H
2 gas target. The recoiling
α particles were measured by three △
E-
E silicon telescopes at three different angles. The total cross sections of
1H(
17F,
α)
14O have been derived at
Ec.m.=2.7~3.4 MeV based on an isotropic angular distribution assumption. Our results are consistent with the previous ones in the energy region of
Ec.m.>3 MeV, and we also obtained some new data in the low energy region, which partly support the destructive interference between the direct and resonant reaction mechanism predicted by the theory.
下载: