Nuclear astrophysics with nucleonic ejectiles

核子弹射物的核天体物理学

• 批准号: 217035-2010
• 负责人: Buchmann, Lothar
• 金额: $ 1.89万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=514171
• 关键词: Nuclear; astrophysics; nucleonic; ejectiles

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.

在核物理和天体物理学中有许多反应，在反应发生后释放出重粒子。它们是用于直接恒星反应的(α，p)和(p，α)类型。此外，核转移反应，如(^6Li，d)和(^3He，d)，以及弹性散射的测量，可以提供有用的核信息来推导恒星反应率。在所有情况下，都需要检测带电的光抛射物。一个特例是(α，n)反应，其中我们计划不探测中子，而是探测重反应伙伴。对于所有这些类型的反应，我们有两种检测设备可用：Tuda和TATY。Tuda是一个复杂的真空室，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低能量实验和ISAC II高能量实验之间移动。在过去的三年里，我们还开发了一个基于气体的时间投影室，名为TATAL。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，来自中心区域发生的反应的重离子一旦散射到检测区域，就可以高效率地被检测到。通常，带电粒子的发射之后是伽马射线的发射。我们采用了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，我们请求购买两台LABR探测器用于测试目的。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相结合。在我们计划与Tuda一起测量的反应中，有一些是关于通过18Ne从热的CNO循环中爆发的。计划间接测量~(14)C(a，g)~(18)O的恒星速率(天王星)。我们还将为海外团体来土达提供一些支持。策略上计划进行~8Li(a，n)~(11)B反应的测量。还计划了7(Be(p，p)7Be和7Li(3He，a)6Li反应的测量。后一种反应需要在TATAL中分离光束和检测区，从而需要另一个气体处理系统。