Study of the spin-dependence of three-nucleon interactions by developing a high-intensity polarized neutron beam

通过开发高强度偏振中子束研究三核相互作用的自旋依赖性

• 批准号: 17340064
• 负责人: OKAMURA Hiroyuki
• 金额: $ 8.77万
• 依托单位: Osaka University (2006)Tohoku University (2005)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17340064/
• 关键词: Spin polarization; Neutron beam; Three-nucleon force; Laser optical pumping; Ion source; 実験核物理; 核力; 多体相互作用

In order to study the spin-dependence of three-nucleon interaction via elastic scatterings of spin-polarized neutron off deuteron, we have developed a highly intense but inexpensive spin-polarized proton source. In this proposal, an atomic beam of polarized hydrogen is produced by exchanging spins with Rubidium vapor, which is polarized with optical pumping by a circularly polarized laser, and then ionized by an ECR ionizer. In the first year of the term, mainly the polarized Rubidium vapor generating system has been developed It is crucial to match the spectral widths between the high-intensity laser and the absorption of Rubidium vapor so that the laser power is efficiently absorbed and accordingly a high polarization and a high vapor pressure can be achieved at the same time. Although high-intensity semiconductor lasers are available at low prices in this spectral region, their widths are usually of order of 1 THz, which is thousand times broader than the Doppler width of 1 GHz, res … More ulting in very poor absorption efficiency. Conventionally very expensive Ti-Sapphire lasers are used for this purpose, employing optical modulators to broaden their extremely narrow widths. Although semiconductor lasers with external cavities are commercially available, they have 1 MHz super-narrow widths and a few mW small powers, as they are usually focused to spectroscopic use. Thus we have developed a laser system suitable for optical pumping, with a broader width of 100 MHz and a high power of 1 W, by employing a Fabry-Perot type external cavity instead of the ordinary grating type. A feedback system for stabilizing the wavelength in a long term and an atomic beam system has been developed in parallel. In the second year of the term, the superconducting ECR ion source started operation and various improVements have been made, e.g., in the beam extraction part and in the beam transport system, by using heavy noble gases. Although the acceleration of polarized ion beam has not been achieved in the term, the system will be completed in the near future, together with the development of polarimeters. Also closer collaboration with theoreticians has been promoted by holding several workshops. Less

为了通过氘核自旋极化中子的弹性散射来研究三核子相互作用的自旋依赖性，我们开发了一种高强度但廉价的自旋极化质子源。在该提案中，通过与铷蒸气交换自旋来产生偏振氢原子束，铷蒸气通过圆偏振激光器的光泵浦进行偏振，然后由 ECR 电离器电离。学期第一年，主要开发了偏振铷蒸气发生系统。高强度激光和铷蒸气吸收之间的光谱宽度匹配至关重要，这样激光功率才能被有效吸收，从而同时实现高偏振和高蒸气压。尽管在此光谱区域可以以低廉的价格获得高强度半导体激光器，但其宽度通常为 1 THz 量级，比 1 GHz 的多普勒宽度宽数千倍，导致吸收效率非常差。传统上非常昂贵的钛蓝宝石激光器用于此目的，采用光学调制器来加宽其极窄的宽度。尽管具有外腔的半导体激光器已经商用，但它们具有 1 MHz 的超窄宽度和几 mW 的小功率，因为​​它们通常专注于光谱用途。因此，我们通过采用法布里-珀罗型外腔代替普通光栅型，开发了适合光泵浦的激光系统，其宽度为100 MHz，功率为1 W。用于长期稳定波长的反馈系统和原子束系统已经并行开发。在任期的第二年，超导ECR离子源开始运行，并通过使用重惰性气体在束流提取部分和束流传输系统中进行了各种改进。虽然偏振离子束的加速在短期内还没有实现，但随着旋光计的发展，该系统将在不久的将来完成。通过举办多次研讨会，也促进了与理论家的更密切合作。较少的

项目成果

Resolving the Discrepancy of 135 MeV pd Elastic Scattering Cross Sections and Relativistic Effects

解决135 MeV pd弹性散射截面与相对论效应的差异

• 发表时间: 2005
• 期刊: Physical Review Letters 95
• 作者: Machida;M. N.;V.P.Ladygin 他;K.Yako 他;K.Sekiguchi 他
• 通讯作者: K.Sekiguchi 他

Spin correlations of strongly interacting massive fermion pairs as a test of Bell's inequality.

• DOI: 10.1103/physrevlett.97.150405
• 发表时间: 2006-10
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: H. Sakai;T. Saito;T. Ikeda;K. Itoh;T. Kawabata;H. Kuboki;Y. Maeda;N. Matsui;C. Rangacharyulu;M. Sasano;Y. Satou;K. Sekiguchi;K. Suda;A. Tamii;T. Uesaka;K. Yako

Cluster states in 13C

13C 中的簇状态

• DOI: 10.1142/s0217732306022031
• 发表时间: 2006
• 期刊: Modern Physics Letters A
• 影响因子: 1.4
• 作者: Y. Sasamoto;T. Kawabata;T. Uesaka;K. Suda;Y. Maeda;S. Sakaguchi;K. Itoh;K. Hatanaka;M. Fujiwara;A. Tamii;Y. Shimizu;K. Nakanishi;K. Kawase;H. Hashimoto;Y. Tameshige;H. Matsubara;M. Itoh;H. Yoshida;M. Uchida
• 通讯作者: M. Uchida

Search for supernarrow dibaryons via the pd→ppX and pd→pdX reactions

通过 pd→ppX 和 pd→pdX 反应搜索超窄二重子

• 发表时间: 2006
• 期刊: Physical Review C 74
• 作者: Fisher;D.A.,..;Sato;B.;et. al.;H.Kuboki 他
• 通讯作者: H.Kuboki 他

2α+τ cluster state in ^<11>B

^<11>B 中的 2α+τ 簇状态

• 发表时间: 2006
• 期刊: Modern Physics Letters A 21
• 作者: Takeda;Y.;T.Kawabata 他
• 通讯作者: T.Kawabata 他