分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: The ambiguity of the structure of 12Be especially in the configuration of 12Be ground state has attracted a lot of attention recently. We notice that the nuclear reaction cross section R at low energy region is sensitive to the surface structure of 12Be, which is greatly impacted by the ground state configuration of 12Be especially by the occupancy probability of the s orbital component. By using existed interaction cross section data of 12Be on C at 790 MeV/nucleon and Glauber model, the upper limit of the s orbital occupation probability of 12Be ground state is roughly determined to be about 56% with Single Particle Model calculations. This demonstrates that the method is very promising to determine the s orbital component of 12Be with proper nuclear-matter density distribution calculations for different orbitals of 12Be ground state. Hence we bring forward to determine the s orbital component of 12Be by measuring the R of 12Be on C and Al at several tens of MeV/nucleon. In this paper, the feasibility and detailed experimental scheme of the R measurement are carefully studied. The precision of the s orbital occupation probability of 12Be ground state is expected to achieve 9% by using the proposed 2% R data.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Beam position monitors (BPMs) have been widely used in all kinds of measurement systems, feedback systems and other areas in particle accelerator field these days. The malfunction of a single BPM can cause serious consequences such as the failure of the orbit feedback and the transverse feedback. A troubleshooting has been made to prevent the defective BPMs from affecting the accuracy and stability of the storage ring in Shanghai Synchrotron Radiation Facility (SSRF). Different types of malfunctions have been successfully identified by using the idea of principal component analysis (PCA).