1. Isochronous mass measurements of 58 Ni projectile fragments at CSRe Xinliang Yan Precision nuclear spectroscope group Institute of Modern Physics, Chinese Academy of Sciences (1)Motivation (2)Experiment & results (3)Recent technical developments (4)Summary & outlook

2. Motivation: mass uncertainty 2 G. Audi, F. G. Kondev, M. Wang et al., Chinese Phys. C 36(12): 1157(2012) M Nucleus = Nm neutron + Zm proton ‒ B nucleus /c 2 The masses of nuclides far-off stability play a crucial role in the understanding of nuclear structure and for astrophysical models rp-process r-process

3. Motivation of the experiment A.Langmeier, et al., APJ 323, 288(1986) H. Schatz, Int. J. Mass Spectrom. 349–350, 181 (2013). AME11 T 1/2 < 100 ms Precision mass measurements of short-lived N=Z‒3 nuclei which were relevant in rp-process X-ray burst For some key nuclei, σ(m) < 50 keV are required in the X-ray burst model calculations. Rapid proton capture process

4. Facilities for mass spectrometry K. Blaum, Phys. Rep. 425 (2006) 1. Rare RI Ring

5. CSRe SFC (K=69) 10 AMeV (H.I.), 17~35 MeV (p) SSC(K=450) 100 AMeV (H.I.), 110 MeV (p) CSRm 1000 AMeV (H.I.),  2.8 GeV (p) Accelerator Facilities Heavy Ion Research Facility in Lanzhou (HIRFL) RIBLL1 RIBs at tens of AMeV RIBLL2 RIBs at hundreds of AMeV Magnet rigidity: 0.7~11.5 Tm Built up in 2007 Built up in 1962 Built up in 2007 Built up in 1988 Xiaohong Zhou, Nuclear Physics News, Vol. 26, No. 2, 2016, P4

6. 6 Procedure of the experiment Principle of Isochronous mass spectrometry Every 24 secs, from CSRm, 58 Ni 19+, 463.36 MeV/u, 10 8 ppp v ~ 0.74c CSRe 9 Be target 15 mm Projectile fragmentation ： ToF detector ;

7. 7 Procedure of the experiment Projectile fragmentation ： ; Every 24 secs, from CSRm, 58 Ni 19+, 463.36 MeV/u, 10 8 ppp v ~ 0.74c 9 Be target 15 mm Principle of Isochronous mass spectrometry

8. From raw data to revolution time spectrum 8 X. L. Tu et al. NIM A 654, 213 (2011) 50Gs/s

9. 9 Correction of the revolution-times X.L. Yan, PhD Thesis(2014) σ(T) = 1.73 ps [minimum]

10. The revolution time spectrum Revolution time (ns) … … 43 Ti 20 Na

11. Mass calibration of the spectrum Revolution time (ns) … … 43 Ti 20 Na

12. Mass calibration results Y. H. Zhang, et al, Phys. Rev. Lett. 109, 102501 (2012) 12 Nuclide N ME(CSRe) (keV) ME(AME11) (keV) 41 Ti76 −15698(28) − 15090(363) 43 V42 − 17916(42) − 18024(233)# 45 Cr ★ 218 − 19514(35) − 19403(196)# 47 Mn119 − 22566(32) − 22263(158)# 49 Fe338 − 24750(23) − 24824(149)# 53 Ni651 − 29630(25) − 29687(298)# 55 Cu19 − 31635(181) − 31568(298)# σ(m)/m ~ 0.5 - 3.5×10 −6 ∈

13. Isomer contamination in the 45 Cr Experimental setup at GSI CSRe 13 (GSI) ME( 45 Cr) = −19515(20) keV  ME( 45 Cr) = −19515(35)keV R. Hoischen et al., J. Phys. G 38 (2011) 035104 Experimental setup at IMP Production target 9 Be, ~21.6 mm Plastic stopper 1 ps/channel

14. Effects of the newly measured masses NuclideCount Sp(AME03) （ keV ） Sp(CSRe) （ keV ） T(1/2) 41 Ti 76 2466(100)#2464(28)82.6(5)min 43 V 42 187(230)#83(43)79(2) ms 45 Cr 218 2139(514)2684(125)60.9(4) ms 47 Mn 119 75(161)#381(38)88(1) ms 49 Fe 338 2549(186)#2720(113)64.7(3) ms 53 Ni 651 2739(175)#3000(74)55.2(7) ms 55 Cu 19 -301(304)#-286(164)27(8) ms One-zone X-ray burst model (p, γ ) ↔(γ,p) equilibrium Recalculation of (γ,p) reactions 14

15. Effects of the newly measured masses NuclideCount Sp(AME03) （ keV ） Sp(CSRe) （ keV ） T(1/2) 41 Ti 76 2466(100)#2464(28)82.6(5)min 43 V 42 187(230)#83(43)79(2) ms 45 Cr 218 2139(514)2684(125)60.9(4) ms 47 Mn 119 75(161)#381(38)88(1) ms 49 Fe 338 2549(186)#2720(113)64.7(3) ms 53 Ni 651 2739(175)#3000(74)55.2(7) ms 55 Cu 19 -301(304)#-286(164)27(8) ms 15 S p +3 σ(S p ) [AME03] S p -3 σ(S p ) [AME03] S p ±3 σ(S p ) [AME03] S p ±3 σ(S p ) [CSRe]

16. NuclideCount Sp(AME03) （ keV ） Sp(CSRe) （ keV ） T(1/2) 41 Ti 76 2466(100)#2464(28)82.6(5)min 43 V 42 187(230)#83(43)79(2) ms 45 Cr 218 2139(514)2684(125)60.9(4) ms 47 Mn 119 75(161)#381(38)88(1) ms 49 Fe 338 2549(186)#2720(113)64.7(3) ms 53 Ni 651 2739(175)#3000(74)55.2(7) ms 55 Cu 19 -301(304)#-286(164)27(8) ms Effects of the newly measured masses β+ decay (γ,p) rec. (p, γ) rec. (α,p) rec. (p,α) rec. Unstable Stable

17. S p ± σ(S p ) [AME03] S p ± σ(S p ) [CSRe] NuclideCount Sp(AME03) （ keV ） Sp(CSRe) （ keV ） T(1/2) 41 Ti 76 2466(100)#2464(28)82.6(5)min 43 V 42 187(230)#83(43)79(2) ms 45 Cr 218 2139(514)2684(125)60.9(4) ms 47 Mn 119 75(161)#381(38)88(1) ms 49 Fe 338 2549(186)#2720(113)64.7(3) ms 53 Ni 651 2739(175)#3000(74)55.2(7) ms 55 Cu 19 -301(304)#-286(164)27(8) ms Effects of the newly measured masses β+ decay (γ,p) rec. (p, γ) rec. (α,p) rec. (p,α) rec. Unstable Stable X.L. Yan, APJ 766, L8(2013)

18. Recent technical developments

19. Further development 1: data analysis P. Shuai, PhD Thesis(2015) σ(T) = 1.73 ps [minimum] σ(T) = 1.05 ps [minimum]

20. Further development 2: slits in CSRe Slits ToF detector X. Xu, et al, PRL 117, 182503(2016) ±30mm

21. Further development 2: slits in CSRe Slits ToF detector σ(m)/m ~ 2.1 ×10 -7 Ex = 378(13) keV X. Xu, et al, PRL 117, 182503(2016) ±30mm ME( 52g Co)=‒34361(8)keV ME( 52m Co)=‒33974(10)keV

22. 22 Further developments 3: Double-ToF IMS P. Shuai, PhD Thesis (2015) X. Xu, PhD Thesis(2015) D-ToF IMS (simulated) ToF detectors D-ToF IMS (simulated) 18.031m

23. 23 Further developments 3: Double-ToF IMS P. Shuai, PhD Thesis (2015) X. Xu, PhD Thesis(2015) D-ToF IMS (simulated) ToF detectors R. J. Chen (2016) Preliminary

24. 24 78 Kr 2009 36 Ar 2015(D-ToF) Summary & Outlook 86 Kr 2011 112 Sn 40 Ar 2016(D-ToF) Borders of observed nuclei H. Xu, et al., Chin. Sci. Bull. 54, 4749 (2009) B. Mei, et al., NIM A 624, 109(2010) X. L. Tu, et al, PRL 106, 112501 (2011) Y. H. Zhang, et al, PRL 109, 102501 (2012) X. L. Yan, et al, Astrophys. J. Lett. 776,L8 (2013) P. Shuai, et al., PLB 735, 327(2014) X. Xu, et al, Chin. Phys. C 39, 104001 (2015). P. Shuai, et al., NIM B 376, 311(2016) X. Xu, et al, PRL 117, 182503(2016) 2012, 2015(slit) Masses known in AME2012 58 Ni 2011, 2014(slit) http://210.77.76.5/wiki

25. Masses known in AME2012 25 Summary & Outlook Borders of observed nuclei H. Xu, et al., Chin. Sci. Bull. 54, 4749 (2009) B. Mei, et al., NIM A 624, 109(2010) X. L. Tu, et al, PRL 106, 112501 (2011) Y. H. Zhang, et al, PRL 109, 102501 (2012) X. L. Yan, et al, Astrophys. J. Lett. 776,L8 (2013) P. Shuai, et al., PLB 735, 327(2014) X. Xu, et al, Chin. Phys. C 39, 104001 (2015). P. Shuai, et al., NIM B 376, 311(2016) X. Xu, et al, PRL 117, 182503(2016) 19 Newly measured masses 21 Precision improved masses http://210.77.76.5/wiki Achieved precision 10 -6 ~10 -7 (10-200 keV)

26. Masses known in AME2012 26 Summary & Outlook Borders of observed nuclei H. Xu, et al., Chin. Sci. Bull. 54, 4749 (2009) B. Mei, et al., NIM A 624, 109(2010) X. L. Tu, et al, PRL 106, 112501 (2011) Y. H. Zhang, et al, PRL 109, 102501 (2012) X. L. Yan, et al, Astrophys. J. Lett. 776,L8 (2013) P. Shuai, et al., PLB 735, 327(2014) X. Xu, et al, Chin. Phys. C 39, 104001 (2015). P. Shuai, et al., NIM B 376, 311(2016) X. Xu, et al, PRL 117, 182503(2016) 19 Newly measured masses 21 Precision improved masses http://210.77.76.5/wiki Masses with σ(m) > 50 keV in AME2012 Achieved precision 10 -6 ~10 -7 (10-200 keV)

27. New HIAF facility in China High Intensity heavy-ion Accelerator Facility (HIAF) 30 Tm Yang, J. C. et al NIM B 317, 263 (2013)

28. 2017-1-1528 Reference: [Observed nuclei] NNDC (http://www.nndc.bnl.gov/chart/) [Predicted nuclei] N. Wang et al., Phys. Lett. B734,215 (2014) [AME2012] M. Wang et al., Chinese Phys. C 36, 1287 (2012) [r-process] H.Geissel et al., AIP Conference Proceeding 831, 108(2006)

29. The Collaborations 29 Y. H. Zhang, H.S. Xu, Y.A. Litvinov, H. Schatz, X. L. Tu, K. Blaum, X. H. Zhou, B. H. Sun, J. J. He, Y. Sun, M. Wang, Y. J. Yuan, J. W. Xia, J. C. Yang, G. Audi, 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, S. Kubono, T. Yamaguchi, Y. Yamaguchi, Y. D. Zang, H. W. Zhao, T. C. Zhao, W. Zhang, W. L. Zhan …