Application Abstract: The high precision mass mmeasurement of short-lived atomic nuclei is the frontier research field of international nuclear physics.The first sub-project of the National Key Research and Development Program"High-precision Nuclear Physics Experimental Research","High-precision nuclear mass measurement based on CSR"focuses on high-precision measurement of the mass of short-lived nuclei with mass number A less than 100.This project relies on the Lanzhou Heavy Ion Cooling Storage Ring(CSR)to develop a new type of time-of-flight(TOF)detector,and is the first international facility to develop double-TOF isochronous mass spectrometry technology.Up to August of 2020,this subject has carried out three rounds of quality measurement experiments using 58Ni,86Kr and 112Sn as primary beams,built up the new isochronous mass spectrometry technologyand based on double TOFs and the data processing has been basically completed.Based on the newly measured mass values,the isospin and the evolution of the second type of shell are studied.In addition,in theory,the first-principles calculations of the masses and low-level excited states of short-lived nuclei have also achieved important results.
