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Spin Excitations in Nuclei (Physics)

原子核中的自旋激发（物理学）

基本信息

批准号：
8912585
负责人：
Richard Lindgren
金额：
$ 35.64万
依托单位：
University of Virginia Main Campus
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1989
资助国家：
美国
起止时间：
1989-07-15 至 1992-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=8912585&HistoricalAwards=false
关键词：
Spin Excitations Nuclei Physics

项目摘要

A nuclear physics program on spin excitations of the nucleus will be carried out by intermediate energy inelastic electron, proton, and pion scattering. New initiatives will be taken towards the study of short range correlations. Complementary studies will focus on unnatural parity states such as "stretched" excitations where the dominant coupling between the probe and the nucleus is the nuclear spin density. Not only can we test models of structure calculations but also test selected effective interactions within the DWIA model of inelastic pion and proton scattering. In addition (e,e') measurements are being extended to higher momentum transfer for selected excitations in order to study the importance of higher-order effects such as meson exchange currents, relativistic effects, and short range correlations. Electromagnetic studies of charge density transitions in light nuclei, through photon and electron induced multi-nucleon knockout reactions. Presently, a highly modular plastic scintillation hodoscope, together with a charged particle magnetic filter for background reduction and lead-scintillation shower counters for electron/photon-neutron discrimination, is under development as a large angular acceptance, high efficiency, medium energy resolution (time-of-flight_ neutron detector for use at LEGS, LAMPS, Bates, and eventually CEBAF.

一个关于原子核自旋激发的核物理程序将通过中能非弹性电子、质子和介子散射进行。将采取新的主动行动来研究短期相关性。补充研究将集中于非自然宇称态，如“拉伸”激发，其中探针和原子核之间的主要耦合是核自旋密度。我们不仅可以测试结构计算模型，还可以测试非弹性介子和质子散射的DWIA模型中选择的有效相互作用。此外（e,e'）测量被扩展到高动量转移的选择激发，以研究高阶效应的重要性，如介子交换电流，相对论效应，和短距离相关性。通过光子和电子诱导的多核子敲除反应，对轻核中电荷密度跃迁的电磁研究。目前，一种高度模块化的塑料闪烁hodoscope，以及用于背景还原的带电粒子磁滤波器和用于电子/光子-中子鉴别的铅闪烁淋浴计数器，正在开发中，作为一种大角度接受度，高效率，中等能量分辨率（飞行时间）的中子探测器，用于LEGS， lamp, Bates，最后是CEBAF。