分类: 物理学 >> 凝聚态:结构、力学和热性能 提交时间: 2017-03-26
摘要: Two cryogenic systems of high purity germanium detector, liquid nitrogen and mechanical coolers, are expound, together with explanations of merits and demerits for each kind of cooling methods. The resolutions of detector to the characteristic lines of 152Eu under different cooling conditions are studied. The laboratory results indicate that the mechanical cooler (X-Cooler II) is an ideal replacement candidate for the liquid nitrogen cooler that is being utilized by BEMS at BEPC-II.
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.