Nuclear astrophysics with nucleonic ejectiles

在核物理学和天体物理学中有许多反应，在反应发生后会发射出重粒子。这些是（alpha，p）和（p，alpha）类型的直接恒星反应。此外，像（^6Li，d）和（^3He，d）这样的核转移反应，以及弹性散射的测量，可以提供有用的核信息来推导恒星的反应速率。在所有情况下，都需要检测带电的光喷射体。一个特殊的情况是（α，n）反应，我们计划不检测中子，但重反应伙伴。对于所有这些类型的反应，我们有两个探测器设施：Tuda和Tactic。Tuda是一个精密的真空室，可以放置各种硅探测器。今年，ISAC II的基础设施已经到位，允许Tuda在ISAC I进行低能实验和ISAC II进行高能实验之间移动。在过去的三年里，我们还开发了一种名为Tactic的气体时间投影室。该腔室在中心具有非光束敏感区，并且没有朝向外部检测区的窗口。因此，一旦来自在中心区域中发生的反应的重离子散射到检测区域中，就可以高效率地检测它们。通常，带电粒子的发射之后是伽马射线的发射。我们使用了Dragon BGO阵列。然而，现有的BGO阵列的探测器太少，无法覆盖战术探测器。因此，我们请求购置两台LaBr探测器用于测试。LaBr探测器具有非常好的时间分辨率，以及良好的能量分辨率和高效率。在我们计划用Tuda测量的反应中，有一些是关于通过18 Ne从热CNO循环中爆发的反应。计划对14C（a，g）18O恒星速率进行间接测量（AV canum veneticorum星）。我们还将为从国外来到图达的团体提供一些支持。对于Tactic，计划测量8Li（a，n）11B反应。还计划测量7（Be（p，p）7Be和7Li（3He，a）6Li反应。后一种反应需要将Tactic中的光束和检测区分离，从而需要另一种气体处理系统。

There are many reactions in nuclear physics and astrophysics in which heavy particles are emitted after the reaction has occurred. These are of the type (alpha,p) and (p,alpha) for direct stellar reactions. In addition, nuclear transfer reactions like (^6Li,d) and (^3He,d), as well as the measurement of elastic scattering can provide useful nuclear information to derive stellar reaction rates. In all cases, the detection of charged light ejectiles is required. A special case are (alpha,n) reactions where we plan not to detect the neutron but the heavy reaction partner. For all these types of reactions we have two detector facilities available: Tuda and Tactic. Tuda is a sophisticated vacuum chamber that allows the placement of various kinds of silicon detectors. This year has seen infrastructure at ISAC II been set in place that allows Tuda to be moved between ISAC I for low energy experiments and ISAC II for high energy experiments. In the past three years, we also have developed a gas based time projection chamber named Tactic. This chamber has a non beam-sensible zone in the centre and no windows toward the outer detecting zone. Thus heavy ions from reactions that occur in the central region can be detected with high efficiency once they scatter into the detection region. Frequently, the emission of charged particles is followed by the emission of gamma rays. We have employed the Dragon BGO array. However, the existing BGO array has too few detectors to allow coverage of the Tactic detector. We therefore request the acquisition of two LaBr detectors for test purposes. LaBr detectors have very good time resolution, as well as good energy resolution combined with a high efficiency. Among the reactions we plan to measure with Tuda are those concerning the breakout from the hot CNO cycle via 18Ne. An indirect measurement of the 14C(a,g)18O stellar rate is planned (AV canum veneticorum stars). We also will provide some support for groups coming to Tuda from abroad. For Tactic a measurement of 8Li(a,n)11B reaction is planned. Also measurements of the 7(Be(p,p)7Be and 7Li(3He,a)6Li reactions are planned. The latter reaction requires a separation of the beam and the detection zone in Tactic and thus another gas handling system.