分类: 物理学 >> 核物理学 提交时间: 2024-05-24
摘要: The recently discovered, extremely proton-rich nuclide18Mg exhibits ground-state decay via two sequential two-proton (2p) emissions through the intermediate nucleus,16Ne. This study investigates the structure and the initial2pdecay mechanism of18Mgby examining the density and correlations of the valence protons using a three-body Gamow-coupled-channel method. The results show that the ground state of18Mgis significantly influenced by the continuum, resulting in a significants-wave component. However, based on the current frame- work, this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the18Mg-18Cpair. Additionally, the time evolution analysis of the18Mgground state suggests a simultaneous2pemission during the first step of decay. The observed nucleon–nucleon correlations align with those of the light–mass2pemitters, indicating a consistent decay behavior within this nuclear region.
分类: 核科学技术 >> 核探测技术与核电子学 提交时间: 2024-02-25
摘要: A combination of scintillator, wavelength shifting (WLS) fiber, and silicon photomultiplier (SiPM) shows excellent performance in the `KLandμdetector (KLM)' of the Belle II experiment. We describe the RD for a similar detection technology with a new scintillator and SiPM, which can be implemented for a muon detector for the proposed CEPC experiment and the upgrade of KLM in Belle II. The RD contains the study of the performance of a new scintillator with a length of 150 cm, the NDL SiPM with a sensitive surface of 3 mm×3 mm or the Hamamatsu MPPC with a sensitive surface of 1.3 mm×1.3 mm, the construction of a detector strip, and the methods to achieve excellent light collection. The cosmic ray tests show good photon collections by NDL SiPM or MPPC, efficiencies well above 90% with a threshold of 8 p.e., and time resolutions of better than 1.7 ns for the hits at the far end of a scintillator strip. The performance shows a good option for an excellent muon detector for CEPC and the possible upgrade of Belle II KLM.