High-precision mass measurements of neutron-rich nuclei Dinko - PowerPoint PPT Presentation

6 th Workshop on Nuclear Fission and Spectroscopy of Neutron-rich nuclei High-precision mass measurements of neutron-rich nuclei Dinko Atanasov Technische Universitaet Dresden

Outline • Motivation • Ion-trap mass spectrometer ISOLTRAP • Experimental techniques (TOF-ICR, MR-TOF MS, PI-ICR) • Results (neutron-rich Cd, Rb, Sr) 2

Mass surface 3

Mass filters ( ) - B Z , N + 2 ( ) - B Z , N - 2 ( ) D 2 N = S 2 N ( N , Z ) - S 2 N ( N + 2, Z ) = 2 B Z , N 132 Sn region A~100 region 4

Radioactive ion-beam facility ISOLDE post-accelerated ISOL beams PSB beam MINIBALL REX-ISOLDE E = 1.4 GeV HRS GPS Low-energy ISOL beams TAS IDS ISOLTRAP CRIS COLLAPS 5

ISOLTRAP setup 6 M. Mukherjee et al. , Eur. Phys. J. A 35 , 1 (2008); S. Kreim et al. , Nucl. Instrum. Methods B 317 , 492 (2013).

Penning-trap mass spectrometry 𝑟𝐶 𝝃 𝒅 = 2𝜌 𝒏 Time-Of-Flight Ion-Cyclotron Resonance Phase-Imaging Ion-Cycotron Resonance 7 M. König et al. , IJMS. 142, 95 (1995); S. Eliseev, PRL 110, 082501

Multi-Reflection Time-Of-Flight Mass Spectrometer Mass measurements 𝒖 = 𝒃. 𝒏/𝒓 + 𝐜 52Cr 39K 52K 52Ca Yield studies Time-structure studies HFS studies ungated gated 8 R. N. Wolf et al. , IJMS 313 , 8 (2012); F.Wienholtz et al. , Nature 489 , 346 (2013)

Mass measurements in the 132 Sn region

Nuclear mass models - uncertainties • Experimental data still missing for 129-132 Cd important r -nuclei • Rely on theoretical extrapolations • Shell evolution far from stability puts constraints on nuclear interaction used ISOLTRAP R. Surmann ECT Workshop (2014), M. Mumpower et al. Prog. Part Nucl Phys, 86:86 – 126, 2016, 9 M. Wang et al., Chinese Phys. C 36, 1603 (2012); M. Bender et al., PRC 73, 034322 (2006); S. Goriely et al., PRC 88, 024308 (2013)

Measurements of 129-131 Cd + 130 Cd + • UCx target equipped with quartz insert • Masses determined by TOF-ICR and MR-TOF MS measurements 129 Cd + 131 Cd + 10 D. Atanasov et al. , PRL 115 , 232501 (2015);

Results Δ (AME - new) (keV) A Ratio r or C ToF ME new (keV) ME AME (keV) −63 148(74) -63 510(200) # 129 0.970 105 338(136) -452 −61 118(22) 130 0.977 645 186(180) -61 530(160) -412 −55 215(100) 131 0.482 304 4(539) -55 331(196) # -116 Δ n = S n ( N , Z ) – S n ( N +1, Z ) S n ( N , Z ) = B( N , Z ) – B( N -1, Z ) 11 D. Atanasov et al. , PRL 115 , 232501 (2015); M. Wang et al. , Chinese Physics C 36 , 1603 (2012).

Isomeric states in 123,127 Cd ISOLTRAP AME12 (keV) (keV) E ex ( 123 Cd) 149(50) 143(4) E ex ( 127 Cd) 270(50) 0#(100#) 20 M. König et al., IJMS. 142, 95 (1995); S. Eliseev, PRL 110, 082501; A. Kankainen et al. PRC 87, 024307 (2013) 12

Isomeric states in 123,127 Cd 85 Rb ISOLTRAP AME12 (keV) (keV) E ex ( 123 Cd) 149(50) 143(4) E ex ( 127 Cd) 270(50) 0#(100#) 20 M. König et al., IJMS. 142, 95 (1995); S. Eliseev, PRL 110, 082501; A. Kankainen et al. PRC 87, 024307 (2013) 12

Mass measurements in the A ≈ 100 region

Onset of deformation at N = 60 M. Wang et al. , Chinese Physics C 36 , 1603 (2012). V. Manea, PhD thesis (2014). A. de Roubin, article and thesis. TITAN: R. Klawitter et al., Phys. Rev. C 93, 045807 (2016). T. R. Rodriguez, Phys. Rev. C 90 , 034306 (2014) 13

101,102 Sr, 98-100 Rb, 98 Kr measurements • Three campaigns in the A ≈ 100 region during the last four years. • 101,102 Sr, 98-100 Rb, 97 Kr measured with Penning trap, 100-102 Rb, 98 Kr with MR-TOF MS. S. Naimi et al. , Phys. Rev. Lett. 105 , 032502 (2010). P. Delahaye et al. ,Phys. Rev. C 74 , 034331 (2006). 14 V. Manea et al. , Phys. Rev. C 88 , 054322 (2013). A. de Roubin, article and thesis in preparation.

Two-neutron Separation energies • New ISOLTRAP data continue the previous trends in the Sr and Rb chains. More precise measurements in the Kr chain are needed. • Beyond-mean- field calculations show that the Kr configurations don’t mix strongly in the ground state. M. Wang et al. , Chinese Physics C 36 , 1603 (2012). V. Manea, PhD thesis (2014). A. de Roubin, article and thesis. TITAN: R. Klawitter et al., Phys. Rev. C 93, 045807 (2016). T. R. Rodriguez, Phys. Rev. C 90 , 034306 (2014) 16

Acknowledgements N. Althubiti, P. Ascher, G. Audi, D. Atanasov , D. Beck, K. Blaum, G. Bollen, M. Breitenfeldt, R. B. Cakirli, T. Cocolios, S. Eliseev, S. George, F. Herfurth, A. Herlert, J. Karthein , J. Kluge, M. Kowalska, S. Kreim, Yu. A. Litvinov, D. Lunney, V. Manea, E. Minaya-Ramirez, M. Mougeot , D. Neidherr, R. Ringle, M. Rosenbusch, A. de Roubin, L. Schweikhard, M. Wang, A. Welker, F. Wienholtz , R. Wolf, K. Zuber Grants No.: 05P12HGCI1 05P12HGFNE ISOLDE Target and Technical Group Mikhail Goncharov, Achim Czasch http:// isoltrap.web.cern.ch