Max-Planck-Institut für Kernphysik, Heidelberg Zhuang GE RIKEN, Wako, Japan Mass measurements of short-lived nuclides at storage rings in Asia and its impacts on Astrophysics

1. Importance of Atomic mass measurements in Astrophysics 2. Principle/setup of mass measurements in CSRe(China) and Rare-RI-Ring(Japan) 3. Results & prospections Outline

M(Z,N) = ∑ m i Physics & Chemistry Basic information requied  m/m ≈ 1·10 -6 Nuclear Physics Mass formula, models, drip lines  m/m ≈ 1·10 -7 Astro-Physics Nuclear synthesis abundance Fundunmental Physics Fundamental constants CPT, EDM, QED  m/m ≈ 1·  m/m < 3·10 -9 Atomic Physics Binding energy in highly charged ions  m/m < 1·10 -8 Weak interaction Symmery tests CVC hypothesis Importance of Masses measurements and Precision  m/m ≈ 1·10 -7 From H.-J.Kluge Eur. J. Mass spectrom. 16 (2010)269

Importance of Masses Measurements in Astrophysics & Nuclear Physics dm/m = Magic Number, Shell & Drip Lines Pairing, Deformation, Halos Nuclear Models & Formula Energy Generation Element abundance Symmetry in Nuclei Nucleo- synthesis path Time Scale & Light Curves z

rp process r process Important nuclear physics input: Atomic masses, half-lives, and reaction rates Atomic Masses in Nuclear Astrophysics

2012 NUBSE 2012 About 2200 nuclear masses were measured 3000 nuclides known nuclides predicted Huge experimental work are needed !

Mass Measurement Facilities Worldwide

Principle & method of

Principle & method of Measurements (Schottky Mass Spectrometry SMS)&(Isochronous Mass Spectrometry IMS) Injection Electron Cooler properties ： high precision ， long- lived>1s Mass Resolution 1.5*10 -7 to 4*10 -8 properties ： low production yield ， short-lived (tens of μs) Mass Resolution 5* Schottky Probe ToF

Experiment process

Revolution time identification 11

Mass calibration

X. Xu et al., submitted to CPC, 2015 Double ToF

Principle & method of

For PTEP2012, 03C009(2012) 0: isochronous 1: non-isochronous Velocity correction is important! measurement ~ reference < measurement < k ~ Principles for Mass measurements 1----velocity correction Unknown mass is measured relative to precisely-known reference mass Two particles with the same momentum have the same flight path length in the ring Revolution time T 0

Rare RI Location of Rare RI Ring at RIKEN RIBF Setup and location Rare RI

For 0: isochronous 1: non-isochronous correction is important here! reference < measurement < Principles for Mass measurements magnetic rigidity correction BRHO CORRECTION FACTOR Machine study to test ???????? Unknown mass is measured relative to precisely-known reference mass Two particles with the same momentum have the same flight path length in the ring Revolution time T 0

Experiment process 48Ca: Mev/u (1 pnA) F1-slit: +/-21.4mm,F2-slit:+/-5mm F1-deg:Al,1.417mm F2-deg:Al,0.485mm F0-Be:25mm

Some Results & Prospections,prosperctive s

Mass measurement results at CSRe-Lanzhou X. L. Tu et al., PRL 106, (2011) X. L. Yan et al. Astrophys. J. Lett. 766, L8 (2013) H. S. Xu et al., IJMS 349, 162 (2013) Beams: 56 Ni, 78 Kr, 86 Kr, 112 Sn, 36 Ar Precision ~10 -7 ( keV) Remeasured 27 Newly measured 26 Double ToF

Impact of CSRe Mass Measurement Mass Measurement of Tz=-1/2 Nuclei ( 65 As)  Waiting Point in the rp-process of X-ray burst

S p ( 65 As) =  keV Effective half-life of 64 Ge Light curve of Type I x-ray burst 89%–90% of the reaction flow passes through 64Ge via proton capture indicating that: 64 Ge is not a significant rp-process waiting point. Abundance of burst ashes Impact on the rp-process of x-ray bursts X.L. Tu etal., PRL 106, (2011)

○ Rare RI Ring ○ MRTOF with main beam ○ MRTOF with parasitic beam How far can we go ? operation measurements Rare RI Ring is about to be put into operation for mass measurements of r- process nuclei Prospections for Rare_RI_Ring

Thanks

Impact of CSRe Mass Measurement Mass Measurement of Tz=-3/2 Nuclei ( 45 Cr)  Test of Ca-Sc Cycle in rp Process

NuclideCount Sp(AME03) （ keV ） Sp(CSRe) （ keV ） T(1/2) 41 Ti762466(100)#2464(28)82.6(5)min 43 V42187(230)#83(43)79(2) ms 45 Cr (514)2684(125)60.9(4) ms 47 Mn11975(161)#381(38)88(1) ms 49 Fe (186)#2720(113)64.7(3) ms 53 Ni (175)#3000(74)55.2(7) ms 55 Cu19-301(304)#-286(164)27(8) ms S p ±3 σ(S p ) [AME03] S p ±3 σ(S p ) [CSRe] One-zone X-ray burst model calculations (p, γ ) ↔(γ,p) Inpact of the 45 Cr mass on the Sc-Ca cycle

X. L. Yan et al ApJ 766 L8 Inpact of the 45 Cr mass on the Sc-Ca cycle S p -3 σ(S p ) [AME03] S p +3 σ(S p ) [AME03] S p ± σ(S p ) [AME03] S p ± σ(S p ) [CSRe]