论文标题
$^{16} $ n的异构光束的机上生产
In-flight production of an isomeric beam of $^{16}$N
论文作者
论文摘要
$^{16} $ n的机上光束是通过在最近升级的Argonne tandem线性加速器系统（ATLAS）flight in-flight系统中的反向运动学中的单个中子添加（$ d $，$ p $）反应产生的。 $^{16} $ n光束的数量在其激动的0.120-mev $ j^π= 0^ - $ isomeric状态（t $ _ {1/2} \ of5 $ $ $ $ $ s）被确定为40（5）％，在反应能量为7.9（3）mev/$ $ $ $，和24 $ $ $ $ $ $ 13.2（2）的反应能量为7.9（3）（3）MEV/$ U $ 13.2（2）。异构体测量值在生产目标下游的实验站$ \ 30 $ m进行，并利用了Al横梁 - 静止的箔和HPGE三叶草检测器。复合$^{16} $ n光束速率确定是在实验站和Argonne机上放射性离子束分离器（RAISOR）的焦平面，该分离器（raisor）用Si $δ$δ$ e-e-e-e望远镜进行。为了估计相对$^{16} $ n异构体的收益率和复合$^{16} $ n光束速率，扭曲的波生近似（DWBA）方法与已知的光谱信息相结合。除了观察到的异构体分数的反应 - 能量依赖性外，还观察到对后坐力的角度接受的敏感性。
An in-flight beam of $^{16}$N was produced via the single-neutron adding ($d$,$p$) reaction in inverse kinematics at the recently upgraded Argonne Tandem Linear Accelerator System (ATLAS) in-flight system. The amount of the $^{16}$N beam which resided in its excited 0.120-MeV $J^π=0^-$ isomeric state (T$_{1/2}\approx5$ $μ$s) was determined to be 40(5)% at a reaction energy of 7.9(3) MeV/$u$, and 24(2)% at a reaction energy of 13.2(2) MeV/$u$. The isomer measurements took place at an experimental station $\approx30$ m downstream of the production target and utilized an Al beam-stopping foil and a HPGe Clover detector. Composite $^{16}$N beam rate determinations were made at the experimental station and the focal plane of the Argonne in-flight radioactive ion-beam separator (RAISOR) with Si $Δ$E-E telescopes. A Distorted Wave Born Approximation (DWBA) approach was coupled with the known spectroscopic information on $^{16}$N in order to estimate the relative $^{16}$N isomer yields and composite $^{16}$N beam rates. In addition to the observed reaction-energy dependence of the isomer fraction, a large sensitivity to angular acceptance of the recoils was also observed.
