| The nucleus is a complex quantum multi-body system that separates the smallest layers of matter,and its structure plays many important role in understanding the world around us and understanding how the universe evolved to this day.It is a challenge to understand how such a system can be constructed,and its decay be described,from a few simple ingredients,protons and neutrons,whose interactions are determined by three of the four forces in nature: strong,weak and electromagnetic forces.The main characteristic of ?-decay far from stability is the large number of decay channels open.The determination of the ?-decay half-life of a nucleus and the comparison with the theoretical predictions give us a glimpse into the global behaviour of such a nuclear system.In the last half a century,a large number of nuclear systems have been studied by the ?-decay process and the interpretation of the results has allowed to advance greatly in the understanding of the organization and behaviour of the nucleons inside the nucleus.The exotic decay mode of ? delayed proton decay essentially reflects the interaction between nuclear cores.The study of various decay modes has become an important way to explore the near-drip nucleus and its nuclear structure.This phenomenon will deepen our understanding and understanding of the nuclear material world.Synthetic results have been achieved in synthesizing new nuclide near the drip line and measuring its peculiar decay properties.Discovering new phenomena and revealing new laws have also led to continuous changes and innovations in experimental methods and techniques.Over the past half century,a large number of nuclear systems have been studied through the decay of ?,and we have made great progress in understanding the structure and behavior of nuclear kernels.The decay process is well understood and the interpretation of the data yields a wide variety of spectroscopic information: level energies,spins,parities,widths and level densities.Spectroscopic studies of the ? decay and ?-delayed particle emission of exotic nuclei are crucial aspects to investigate the nuclear properties and to obtain the structure information close to the drip line,which will lead to a comprehensive description of nuclei,a stringent test of fundamental symmetries and shell-model theories far from the stability line,and also provide an insight into the nature of the basic interactions affecting the structure of nuclei.This paper briefly reviews the decay principle of some peculiar decay modes,and the current research status of peculiar nuclear decay,and introduces the experimental study of29 S ? delayed proton decay.The asymmetry parameter of the29 S nuclear is determined by comparison with the mirror nuclei of the mirror nuclei29 Al.The29S ?-delayed proton decay experiment was carried out on the Lanzhou radioactive beam of the Institute of Modern Physics of the Chinese Academy of Sciences.In the continuous beam mode,the proton spectrum,?-ray spectrum,halflife,energy level and branch ratio of29 S ?-delayed proton decay were measured,and the decay scheme was reconstructed.Silicon detector arrays are critical to charged particle decay studies.A detection system composed of several double sided silicon strip detectors(DSSD)and quadrant silicon detectors(QSD)was specially designed.In order to extract reliable information about the very rare decay events from disturbances,a high signal-to-noise ratio and operation stability of the detection system should be achieved.Several techniques and solutions such as printed circuit boards,cryogenic cooling system,leading edge discrimination,front-back coincidence of DSSD,and energy calibration from an internal source were conceived and implemented on the bases of our previous experiment with an implantation method.Besides,five clover type high purity germanium(HPGe)detectors were employed to measure the ? rays.Simultaneous measurement of ?-delayed proton and ? decay of24 Si was conducted for the first time.Comparing the experimental results with the existing literature data,the reliability of the experimental results and the reliability of the data processing program were confirmed,and six new proton branches and two new energy levels were found.The final decay state of the 3414 ke V proton peak and the decay final state of the 3570 ke V proton peak were found to be disagreed with previous experiments.Compared with the previous literature data,some improved results are obtain,demonstrating the high detection efficiency and low detection threshold of our detection system for charged particles in the decay. |
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