Synthesis Of Re Isotopes Near Proton Droplet Lines

The synthesis of new nuclides began in 1934 when the Curie couple first artificially synthesized the radioactive nuclide 30P.Since then,as people’s understanding of atomic nuclei has deepened,synthesizing new nuclides and searching for the limits of nuclide existence have gradually become the forefront of nuclear physics research.The study of nuclei near the proton drip line,one of the basic limits of nuclear existence,and the synthesis of new nuclides that cross the proton drip line,are very important fields in nuclear physics research.Proton radioactivity research is one of the important means to obtain information on atomic nucleus structure in the area of neutron-deficient nuclei beyond the proton drip line.Research has found that compared with other nuclides in the 67≤Z≤75 nuclear region,there is a relatively lack of neutron-deficient isotopic data for the element Re and its isotopes near the N=82 neutron shell have yet to be discovered.So far,the most neutron-deficient isotope of Re,¹⁵⁹Re,was synthesized nearly 20 years ago.Since then,research for many years has been stagnant due to interference from β decay in the decay chain of nuclides in this nuclear region,as well as the relatively short half-life of new nuclides.In order to break through research bottlenecks,search for new Re isotopes outside the proton drip line that are most deficient in neutrons,and study the influence of the N=82 neutron shell on nuclide properties,experimental studies on synthesizing the new nuclide ¹⁵⁸Re were carried out on the gas-filled spectrometer at the Institute of Modern Physics of the Chinese Academy of Sciences.Through fusion-evaporation reaction ⁵⁸Ni+¹⁰⁶Cd,multiple neutron-deficient Re isotopes including ¹⁶³Re,162Re,¹⁶¹Re,¹⁶⁰Re were identified in the experiment.Suspected ¹⁵⁹Re events has been found in the experiment.The new isotope ¹⁵⁸Re has not been discovered yet,and more time is needed for further thorough study of the data.The article provides detailed description of the entire experimental process.The residual nuclei produced from the reaction were recoiled out of the experimental target,and the gas-filled spectrometer separated the target nuclide from background particles based on the different magnetic rigidities of the particles during the recoil process,and transferred it to the focal plane detection system.Then,the Si-box detectors in the focal plane detection system detected the injection nucleus and subsequent proton and alpha decay,and the signals and waveforms were recorded and saved by the digital signal acquisition system.The data was processed by energy-position-time correlation and identified based on the decay properties of the nuclides as described in Chapter 2 of the article.The decay energy spectrum of the injected nucleus in the experiment was able to reproduce the results of previous literature studies,demonstrating the validity of the experiment.In addition,this experiment is the first to observe protons in the PSD detector of the Lanzhou focal plane detection system,which fully demonstrates the performance of the PSD detector and expands the range of equipment research.The protons identified in the data come from ¹⁶¹Re,¹⁶⁰Re and ¹⁵⁷Ta,and after proton energy correction,the results are consistent with the previous research.Finally,this article concludes with a summary of the unfinished work and proposes the next research focus and solution methods.It is hoped that satisfactory results can be achieved in future work.