Study of New-Modes of Nuclear Excitation by Means of High-Resolution (p,n) Measurement

通过高分辨率 (p,n) 测量研究核激发新模式

基本信息

批准号：
59540147
负责人：
ORIHARA Hikonojo
金额：
$ 1.73万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

项目摘要

Charge-exchange (p,n) reactions have been proved to be an excellent tool to study new mode s of nuclear excitation , where spin-isospin excitations are observed, for example. The (p,n) reaction has been recently investigated by means of two different proton energies; i.e. (p,n) work at intermediate energy carried out at IUCF (Indiana University Cyclotron Facility), and the other works have been carried out at CYRIC (Cyclotron and Radioisotope Center, Tohoku University) with 35 MeV protons. Due to strong spin-dependent force, the intermediate (p,n) works seem to be much reliable. However, low energy (p,n) reactions may be studied with much better energy resolution. In this project, we have extensively developed the high-resolution measurement by means of the neutron time-of-flight facilities. It should be noted that to achieve a ultimated high-resolution of 100 keV v.s. 30 MeV neutrons a long flight path (44 m) is required. Thus development of the high efficient detector system was also needed.One of the current interests studied by the high-resolution (p,n) measurement is the <0^+> <-!>> <0^-> transition, which carries selectively information on one-pion exchange interaction. We have studied <DELTA> <J^pi> = <0^-> reactions on <^(13)C> , <^(14)N> and <^(15)N> . A shoulder was systematically observed around 50゜ in the angular distributions for the 1/ <2^-> <-!>> 1/ <2^+> and <1^+> <-!>> <1^-> transitions. This shoulder was interpreted as being due to the tensor interaction in the <DELTA> J( <DELTA> L, <DELTA> S) = 0 (1,1) channel. Other topics such as the <0^+> <-!>> <1^+> Gamow-Teller type transition have been extensively studied on s-d shell nuclei. One of the new modes of nuclear excitation, an example for which is <DELTA> J( <DELTA> L, <DELTA> S) = 2(1,1) or 1(1,1), were studied at <E_p> = 41 MeV for heavier nuclei.

电荷交换（p，n）反应已被证明是研究新的核兴奋模式的绝佳工具，例如，观察到自旋 - 呈刺激兴奋。最近通过两种不同的质子能进行了（p，n）反应。即（p，n）在IUCF（印第安纳大学回旋设施）进行的中级能量工作，其他作品是在Cyric（Cyrcron and Radisasotope Center，Tohoku University）的35 MEV质子上进行的。由于强大的旋转力，中间（P，N）作品似乎非常可靠。但是，低能量（P，N）反应可以研究以更好的能量分辨率进行研究。在这个项目中，我们通过中子飞机设施广泛开发了高分辨率测量。应当指出的是，要实现100 Kev V.S.的最终高分辨率。 30 meV中子需要长途飞行路径（44 m）。还需要高效探测器系统的开发。通过高分辨率（P，N）测量研究的当前利益之一是<0^+> <-！>> <0^ - >过渡，它可以选择性地提供有关一位二型交换相互作用的信息。我们已经研究了<delta> <j^pi> = <0^ - > <^（13）c>，<^（14）n> and <^（15）n>上的反应。在1/ <2^ - > <-！>> 1/ <2^+>和<1^+> <-！>> <1^ - > transitions的1/ <2^ - ！>> <2^+>和<2^ - ！>> <2^+> <-2^+> <-2^+> <-！该肩膀被解释为是由于<delta> j（<delta> l，<delta> s）= 0（1,1）通道中的张量相互作用所致。其他主题，例如<0^+> < - ！>> <1^+> gamow-teller型转换已广泛研究了S-D Shell Nuclei。在<delta> l，<delta> l，<delta> s）= 2（1,1）或1（1,1）的一个新核兴奋模式之一中进行了研究，以<e_p> = 41 MEV的重量较重。