Mass, half-life, and reaction cross-sections are basic properties of atomic nucleus.
Our research group focus on the precision measurements of the mass and half-life of short-lived nuclides, using the experimental Cooler Storage Ring (CSRe) at the Heavy Ion Research Facility in Lanzhou (HIRFL-CSR). As one of the existing high-energy heavy-ion facilities, HIRFL-CSR provides an opportunity for performing in-ring direct nuclear reactions induced by light ions with the internal gas-jet target. The related experimental programs are under development in our group.
Great effects have been devoted in the research and design of the SRing mass spectrometry and in-ring nuclear reaction spectrometry for the High Intensity heavy-ion Accelerator Facility (HIAF), which is under construction in Huizhou, Guangdong.
Since 2011, our group took the leading role in the International Atomic Mass Evaluation (AME) collaboration.
1. Precision mass and half-life measurements of short-lived nuclides, R & D of the Time-Of-Flight detectors and Schottky detectors.
2. Nuclear reaction measurements in the storage ring, R & D of the in-ring direct nuclear reaction spectrometry.
3. International Atomic Mass Evaluations, collecting and evaluating all the relevant atomic mass data appeared in the publications.
In recent years, high-precision mass measurements of short-lived nuclides were conducted using the isochronous mass spectrometry (IMS) based on the HIRFL-CSR facility in Lanzhou, China. The new data enable us to discuss some related physical problems in the realm of nuclear structure and astrophysics. A novel magnetic rigidity recognized isochronous mass spectrometry utilizing two time-of-flight detectors was successfully developed and implemented in the online experiments. The new technique provides new way of measuring the machine parameters of a storage ring, such as the momentum compaction factor and betatron tune, and enables us to precisely control the settings of the storage ring. As a result, the mass resolving power is greatly improved while keeping the acceptance of the ring unaffected.
To build the in-ring direct nuclear reaction spectrometry at HIRFL-CSR, a silicon strip detector compatible with the ultra-high vacuum in the CSRe ring has been developed and commissioned. Proton elastic scattering experiments on the 58Ni and 78Kr nuclei have been conducted successfully using this detector. From the measured differential cross sections at low momentum transfer, the nuclear matter distribution radii of 58Ni and 78Kr were extracted. The results agreed with theoretical predications, showing the reliability of the newly developed in-ring nuclear reaction spectrometry at CSRe.
1) M. Zhang, Y.H. Zhang, M. Wang et al., Precision measurement of the transition energy γt versus magnetic rigidity for storage-ring isochronous mass spectrometry, Nucl. Instrum. Meth. A 1027, 166329 (2022).
2) Xu Zhou, Meng Wang, You-Jin Yuan et al., Charge resolution in the isochronous mass spectrometry and the mass of 51Co, Nuclear Science and Techniques, 32:37 (2021)
3) X. Zhou, M. Zhang, M. Wang, Y. H. Zhang, Y. J. Yuan et al., In-ring velocity measurement for isochronous mass spectrometry, Physical Review Accelerators and Beams 24, 042802 (2021)
4) J.T. Zhang, X.L. Tu, P. Sarriguren, K. Yue et al., Systematic trends of neutron skin thickness versus relative neutron excess, Phys. Rev. C 104, 034303 (2021)
5) W.J. Huang, Meng Wang, F.G. Kondev, G. Audi and S. Naimi, The AME 2020 atomic mass evaluation (I). Evaluation of input data, and adjustment procedures，Chinese Phys. C 45 030002 (2021)
6) Meng Wang, W.J. Huang, F.G. Kondev, G. Audi and S. Naimi, The AME 2020 atomic mass evaluation (II). Tables, graphs and references，Chinese Phys. C 45 030003 (2021)
7) F.G. Kondev, M. Wang, W.J. Huang, S. Naimi and G. Audi, The NUBASE2020 evaluation of nuclear physics properties, Chinese Phys. C 45 030001 (2021)
8) M. Wang, Y.H. Zhang, H. Y. Jiao, The progress of nuclear mass measurement experiments based on HIRFL-CSR (in Chinese), Chinese Science Bulletin 66(27), 3517-3526(2021)
9) Q. Zeng, J. T. Zhang, K. Yue, X.L. Tu, Progress on internal gas-jet target nuclear reaction at the HIRFL-CSR (in Chinese),
Chinese Science Bulletin 66(26), 3395-3404 (2021)
10）H.Y. Deng, M. Wang, Y.H. Zhang, C.Y. Fu et al., Progress of Isochronous Mass Spectrometry at HIRFL-CSR (in Chinese)，Nuclear Physics Review 37(3), 301-308 (2020).
11) Meng WANG，Nuclear Mass Measurement and Evaluation (in Chinease), Nuclear Physics Review 34(3)，380（2017）
Prof. WANG Meng
Mailing Address: 509 Nanchang Rd., Lanzhou, China, 730000