质子滴线核26Pβ延迟双质子发射机制的实验研究

Remarkable progress in the study of two-proton (2p) emission has been made in recent years. One of the next destinations is the realization of high-precision direct measurements of decay-energy and emission-angle correlations in β-delayed two-proton (β2p) emission. In this project, β2p correlated emission from the ground state of 26P at the proton drip line is planed to be studied with the direct measurement. A new experimental device composed of double-sided silicon strip , quadrant silicon and clover detectors will be used in the experiment. Having a very large angular coverage and high granularity, the detector array allows simultaneous measurements of energy, time and space distributions of charged particles in the β-delayed decay of 26P. According to experimental results, we will investigate the breakup of a quantum three-body system, exotic structure, pairing interactions, and so on...The project will be another subject of 2p emission from proton-rich nuclei following studies of 27,28P and 28,29S and the systematic research will be conducive to acquire a better knowledge of exotic characters and evolution rules of nuclei close to the proton drip line in the Z≈15 region.

近年来，国际核物理前沿领域之一双质子发射已取得令人瞩目的科研成果。实现β缓发双质子衰变能量与发射角度的高精度直接测量将是科研人员下一阶段追求的目标之一。本项目计划采用直接测量方法研究质子滴线核26P基态β延迟双质子发射的机制。实验中拟使用一种新型的探测器阵列，由双面硅条、四分硅以及Clover组成，具有大立体角与高颗粒度等优良性能。此阵列可记录26P基态β缓发粒子的能量，时间与空间信息，从而研究量子三体系统的破裂机制、奇特的核结构以及对关联等基本物理问题。..本项目将是我国科研人员继27,28P与28,29S体系之后又一次对丰质子核开展双质子发射实验，系统化的研究有助于我们探索Z≈15附近丰质子近滴线核的奇特性质以及变化规律。

本项目成功研制的硅探测器阵列由双面硅条探测器、四分硅以及高纯锗探测器组成，具有大立体角与高颗粒度等优良性能。该探测器阵列可以记录26P、27S基态β缓发粒子的能量、时间、空间等信息。实验获得了高统计、低本底的26P、27S基态β延迟质子、伽玛发射能谱以及双质子发射的角关联信息，不仅对天体环境下26Si、27P的关键共振态进行直接的实验测量，而且可以研究量子三体系统的破裂机制、奇特的核结构以及对关联等基本物理问题。