Application of Inring Slit on Isochronous Mass Spectrometry

Application of In-ring Slit on Isochronous Mass Spectrometry Xing XU Institute of Modern Physics, Chinese Academy of Sciences Sep 20, 2018, Geneva, Switzerland

Outline Ø Brief introduction to isochronous mass spectrometry Ø Description of in-ring slit method Ø Mass Measurements for several low-lying isomers Ø Summary

Introduction: nuclear mass Binding energy Nuclear Mass Field of application Required uncertainty Chemistry: identification of molecules IMS 10 -5− 10 -6 Nuclear physics: shells, sub-shells, pairing 10 -6 Nuclear fine structure: deformation, halos 10 -7− 10 -8 Astrophysics: r, rp-process, waiting points 10 -7 Nuclear models and formulas: IMME 10 -7− 10 -8 Weak interaction studies: CVC, CKM 10 -8 Atomic physics: binding energy, QED 10 -9− 10 -11 Metrology: fundamental constants, CPT <10 -10 K. Blaum et al. , Phys. Rep. 425, 1 (2006)1

Experiment at CSRe at CSR Introduction: IMS experiment e. C foil MCP CSRe TOF Detector RIBLL 2 CSRe CSRm ~600 ns/ revolution ≥ 100 revolution Half-life ≥ 100 us

Introduction: principle of IMS T=L/v Bρ=m/q βγc

Introduction: in-ring slit M. Matos. Ph. D thesis, Justus-Liebig University at Gießen, 2004.

Introduction: in-ring slit beam pipe 200 mm slit

Introduction: in-ring slit beam pipe 200 mm slit

Experimental result from 58 Ni fragments 52 Co Without slit With slit Red: Tz= -1 Blue: Tz= -1/2 Mass resolving power m/Δm~210, 000 With slit of 60 mm wide PRL 117, 182503 (2016) PLB 767, 20 -24(2017) PRC 98, 014319(2018)

Experimental result from 112 Sn fragments N=49 isotones Z=49 isotopes 1/2 - proton(neutron) –hole 9/2+ ground state Isomer state

Experimental result from 112 Sn fragments Mass resolving power m/Δm~310, 000 With slit of 50 mm wide

Experimental result from 112 Sn fragments Two new isomers are discovered

Summary Ø In ring slit method has been successfully applied on Isochronous mass spectrometry at HIRFL-CSR facility in Lanzhou. Ø Mass resolving power have been improved by 2~3 times. Ø A series masses of Tz=-1 nuclei in pf-shell are measured with precision ~10 ke. V Ø New isomers in 101 In and 95 Pd are discovered.

Thanks for your attention H. S. Xu Y. H. Zhang, X. L. Tu, X. L. Yan, M. Wang, X. H. Zhou Y. J. Yuan, J. W. Xia, J. C. Yang, X. C. Chen, G. B. Jia, Z. G. Hu, X. W. Ma, R. S. Mao, B. Mei, P. Shuai, Z. Y. Sun, S. T. Wang, G. Q. Xiao, X. Xu, Y. D. Zang, H. W. Zhao, T. C. Zhao, W. Zhang, W. L. Zhan (IMP-CAS, Lanzhou, China) Yu. A. Litvinov, S. Typel (GSI, Darmstadt, Germany) K. Blaum (MPIK, Heidelberg, Germany) Y. Sun (Shanghai Jiao Tong University, Shanghai, China) Baohua SUN (北航) H. Schatz, B. A. Brown (MSU, USA) G. Audi (CSNSM-IN 2 P 3 -CNRS, Orsay, France) T. Yamaguchi (Saitama University, Saitama, Japan} T. Uesaka, Y. Yamaguchi (RIKEN, Saitama, Japan)