Novel uses of Penning traps in nuclear structure physics. Mass measurements. Thanks to many colleagues at ISOLTRAP, SHIPTRAP and JYFLTRAP

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1 Novel uses of Penning traps in nuclear structure physics Mass measurements Thanks to many colleagues at ISOLTRAP, SHIPTRAP and JYFLTRAP

2 Physics & Chemistry basic information required δm/m Nuclear Physics nuclear binding energies, Q-values δm/m Nuclear Structure shell closure, pairing, deformation, halos δm/m Weak Interaction symmetry tests, CVC hypothsis δm/m < Astro- physics nuclear synthesis, r- and rp-process δm/m < δm/m Fundamental Property tests of nuclear models and formulars Courtesy: K. Blaum

3 Gaining Precision: From Past to Present Bulk properties, liquid drop, shells Sub-shells, pairing, halos Symmetries, fundamental tests of concepts RF Spectrometers Mass Spectrographs Reaction Q PTMS K. Blaum

4 AME2003, G. Audi et al., Nucl. Phys. A 729 (2003) 3

5 nuclear structure and nuclear astrophysics studies Mass accuracy < 12 kev AME2003, G. Audi et al., Nucl. Phys. A 729 (2003) 3

6 Accuracy required for fundamental physics Mass accuracy < 1 kev AME2003, G. Audi et al., Nucl. Phys. A 729 (2003) 3

7 Direct Mass Measurement Techniques in Nuclear Physics ACCURACY δ m/m SPEG TOFI ESR-TOF JYFLTRAP ISOLTRAP TITAN MISTRAL ESR Schottky HALF-LIFE RANGE [s] D. Lunney

8 Mass measurement programs for radionuclides (since 1994) Z stable indirect GANIL SPEG CSS2 ISOLDE MISTRAL ISOLTRAP GSI ESR-SMS ESR-IMS proton dripline (FRDM95) a possible r-process neutron dripline (FRDM95) New (Penning trap) CPT (ANL) LEBIT (MSU) SHIPTRAP (GSI) JYFLTRAP MAFF (FRM II) TITAN (TRIUMF) N Lunney, Pearson & Thibault, Rev. Mod. Phys. 75 (2003)

9 Highlights from TRAP facilities GSI: masses of rp nuclei Proton drip-line nuclei Argonne: 46 V, 64 Ge heavy fission products MSU: 38 Ca, 70m Br, 68 Se 44 S, n-rich 65 Fe and 66 Co CERN: ~300 isotopes measured 22 Mg, 32 Ar, 72 Kr 74 Rb, 81 Zn, 133 Sn TRIUMF 9,11 Li, 8 He 50 Jyväskylä: ~200 isotopes measured 23 Al, 62 Ga, 92 Rh fission products; 83 Ga, 110 Mo

10 Complementary of Penning trap projects Type of reaction ISOL- TRAP CPT SHIP- TRAP JYFL- TRAP LEBIT MAFF- TRAP TITAN SMILE- TRAP HI- TRAP MATS/ FAIR ISOL x x fusion x x IGISOL x fragmentation x x x neutronfission x highlycharged x x x x stable (x) x x trap ass. spectros. (x) x x Present facilties are complementary New facilities are needed

11 Macroscopic mass ( ) ( ) ) (, ) ( 0, ) (, ) 2 ( 1, 1 2 1/ 3 2/ 3 o o e o e e A Z A a A Z Z a A a A a Z A B A C s V + + = δ δ RMS deviation of 2.97MeV! (1995 data) (without pairing term, excluding shell structure)

12 Predictive power of mass models; MeV MeV D. Lunney et al. Rev. Mod. Phys. 75 (2003) 1021

13 Differences in mass precictions to Duflo & Zucker

14 Do we need precision measurements in nuclear physics at all? Absolutely: YES!

15 Nuclear mass-related observables Absolute mass --- total binding energy --- Limits of nuclear existence Mass differencies First order derivatives Nucleon (s. p.) binding energy (drip-line definition) Nucleon-pair binding energy (S 2N ) Decay energy (Q β, Q α ) Coulomb displacement energy (Isospin multiplets) Second order derivatives Pairing energy (odd-even staggering) Shell-gap energy (evolution of magicity) Energy difference of spin-orbit partner states V s0 (l. s) Valence proton-neutron interaction energy δv pn

16 Nuclear structure ( kev) Global correlations (100 (100 kev) kev) Local correlations (10 (10 kev) kev) shell shell structure, spin-orbit interaction, pairing, collectivity Drip-line phenomena and and halos (1 (1 kev) kev) Nuclear astrophysics (1 (1 kev) Charge symmetry in in nuclei (100 ev) Isospin multiplets Coulomb energy differences Test of Standard Model (< 100 ev) δm/m << Nuclear β decay. Electroweak interaction CVC theory and and unitarity of of CKM matrix Neutrinoless double β decay

17 Mass measurements for NUCLEAR STRUCTURE IMPACT ON R-PROCESS?? Spin-orbit force? Pairing interaction? Effective force? Continuum-coupling?

18 J.Dobaczewski and W.Nazarewicz Phil. Trans. R. Soc. Lond. A356, 2007 (1998) 48 Ca 132 Sn Shell gap energy and magicity? 78 Ni 208 Pb 100 Sn

19 Shell-gap energies a measure of magicity Across the magic proton shell Z 0 δ 2p (Z 0,N)= S 2p (Z 0,N)-S 2p (Z 0 +2,N) Across the magic neutron shell N 0 δ 2n (Z,N 0 )= S 2n (Z, N 0 )-S 2n (Z,N 0 +2)

20 10 Shell Gap = S 2n (Z,N 0 )-S 2n (Z,N 0 +2) 8 N=20 Shell Gap AME03 8 N=28 Shell gap AME03 Shell Gap (MeV) Shell Gap (MeV) N=50 Shell Gap Z Is there mutual support of magicities 7 farjyfltrap AME from 03 data stability? systematics N=82 Shell Gap Z AME03 Shell gap (MeV) 4?? Shell gap (MeV) Z Z

21 Shell gap energies theory perspective J.M. Pearson and S. Goriely, Nucl. Phys. A 777 (2006) Z=28 2n (N o ) = S 2n (N o )-S 2n (N o +2)

22 JYFLTRAP V. Kolhinen et al., NIM A 528 (2004) 776 S. Rinta-Antila et al., PRC 70 (2004) (R) A. Jokinen et al., IJMS 251 (2006) 241 RFQ K130-accelerator + IGISOL: Fission, light-ion fusion or heavy ion fusion evaporation reactions. Mass-separated (M/ M~300), 1+ DC ion beam at 30 kev of various elements Zr 101 Nb 101 M o Spectroscopy Counts FW HM = 20 Hz M/ M = Y Frequency [Hz] 7 T superconducting 30 kv: Purification trap ( M/M < 10-5 ): Cylindrical 10-4 mbar, B/B = 10-6 in 1 cm 3 Precision trap ( M/M < 10-6 ): Cylindrical trap in vacuum, B/B = 10-7 in 1 cm 3 f f c c,ref f c 1 = 2π q m B m - me = m - m ref e 120 Pd

23 Calibration with withc cluster clusterions Detectors The JYFLTRAP setup Penning traps C kv platform RFQ Laser ablation of Sigradur glassy Brilliant Nd:YAG V. Elomaa, private communication

24 Mass measurements of (refractory) neutron-rich nuclei MeV and µa Nuclear structure aspects: Shell closure at N=50 Subshell closure at N=56 Onset of large deformation at N>58 Transitional behaviour, Zr Pd Calc. yields, V. Rubchenya Astrophysics motivation Location of r-process path: (n,γ) (γ,n) equilibrium. λ γn T N 3 2 n e Sn kbt λ nγ S n 3 MeV

25 New mass measurements of fission products ISOLTRAP at CERN JYFLTRAP STABLE 100 Sn 132 Sn Z NEW MASSES Niobium? T 1/2 100 ms Br: S n =3.2 MeV Ni N [mass(ame2003) - mass(exp)] / MeV m m Nb isotope

26 More Moreexamples Neutron-rich nuclei are aregenerally less less bound than thanestimated in in AME03!!!!!!

27 Comparison to mass predictions Binding energies are needed for network calculations R-process path mostly out of reach in the laboratory Mass predictions and extrapolations Plenty of models: HFB-x, S. Goriely et al. FRDM by Möller and Nix Kuty-models, T. Koura et al., Duflo-Zuker model AME2003 (G. Audi et al., ) New data is needed to benchmark different models and to provide new input ME(exp.)-ME(HFB-8) [kev] The best model in terms of RMS dev. (635 kev) Comparison to the new data: Average deviation -80 kev RMS deviation 513 kev ( by A. Jokinen ) HFB-8, S. Goriely et al Mass number Br Rb Sr Zr Mo Tc Ru Rh Pd

28 Two-neutron separation energies, S 2n 2n S 2n sensitive for structure effects Casten triangle O(6) γ-soft S 2n [MeV] S 2n (N,Z) = B(N,Z) B(N 2,Z) Pd Rh Ru Tc Mo Zr Sr Rb Br E(5) Pd Ru Tc Mo Zr 104 Zr U(3) Spherical X(5) SU(5) rotor Neutron number Sudden drop in S 2n due to shell closure at N=50. Change of deformation Coincides with observed shape changes for Zr and Y isotopes U. Hager et al, PRL 96(2006) S. Rahaman et al, Eur. Phys. J. A32(2007)87 Changes from gamma-soft/triaxial nuclei to almost perfect vibrator A smooth trend dominated by the asymmetry term in LD-presentation U. Hager et al, Phys. Rev. C, in press

29 Charge Chargeradii radiiand andss2n2n

30 Two-neutron binding bindingenergy energyacross acrossn=50

31 Experimental N=50 shell gap S 2n [MeV] N=46 N=48 N=50 N=52 N=54 N=56 Next critical masses: 82 Zn, 77,79,81 Cu, 76,78,80 Ni RIBF and FAIR! Proton number Z

32 Density functional theories T. Otsuka, et al., PRL (2006) M. Bender et al., PRC (2006). M. Stoitsov et al., PRC (2003).

33 Experimental Z=28 shell gap New trap data S. Rahaman et al., Eur. Phys. J. A 34 (2007) 5

34 Pairing energies 2.2 Pairing energy n [MeV] Se Sr Zr Mo Ru Pd Pd 12A -1/2 Se 12A -1/2 n = ¼(-1) A-Z+1 [S n (A+1,Z)-2S n (A,Z)+S n (A-1,Z)]c 2 = ¼(-1) A-Z+1 [-M(A+1,Z)+3M(A,Z)-3M(A-1,Z)+M(A-2,Z)]c Neutron Number

35 Charge symmetry effects in nuclear structure Mirror nuclei and states Isospin multiplets

36 Test of charge (in)dependence in nuclear interaction Example of T=3/2 isospin multiplet 23 Al Ne 13 T=3/2, 5/2 + Mass energy ± 310 ev New JYFLTRAP data: 23 Al and 23 Mg + E γ (T=3/2) T=1/2, 3/ Mg Na 12 Switch on Coulomb interaction! E.P. Wigner 1957 / pure Coulomb IMME: M(A,T,T z ) = a + b T z + c T z 2 23 Al 10 ± 620 ev ± 370 ev 23 Mg 11 ± 150 ev ± 2.7 ev 23 Na 12 ± 100 ev 23 Ne 13

37 PRELIMINARY! A=23 is the most accurately known isospin multiplet IMME: M(A,T,T z ) = a + b T z + c T 2 + z d T 3 z A= 23 quartet: d = 0.15 ± 32 kev perfect quadratic fit!? ISOLTRAP 32 Ar, 33 Ar, 35 K, 36 Ca

38 Mass measurements for nuclear astrophysics

39 Astrophysical processes Heavy-ion reactions ( 32 S+ 54 Fe, 58 Ni+ 58 Ni) Light-ion reactions (p, 3 He beams) on enriched n- deficient targets νp process?

40 Rp-process path for steady-state burning, H. Schatz et al., Phys. Rev.Lett. 86, 3471 (2001) Sequence of (p,γ) and (α,p) reactions and beta decays Nuclear physics data scarce: Q-values and S p -values needed Proton capture rate (p,γ) exp(-q p /kt) JYFLTRAP SHIPTRAP LEBIT CPT 100 new masses of rp-nuclei F (9) O (8) N (7) C (6) B (5) Be (4) Li (3) He (2) H (1) As (33) Ge (32) Ga (31) Zn (30) Cu (29) Ni (28) Co (27) Fe (26) Mn (25) Cr (24) V (23) Ti (22) Sc (21) Ca (20) K (19) 2324 Ar (18) Cl (17) 2122 S (16) P (15) Si (14) Al (13) 1516 Mg (12) Na (11) 14 Ne (10) Tc (43) Mo (42) Nb (41) Zr (40) Y (39) Sr (38) Rb (37) Kr (36) Br (35) Se (34) Sb (51) Sn (50) In (49) Cd (48) Ag (47) Pd (46) Rh (45) Ru (44) Waiting points! Example: 72 Kr(pp,γ) 74 Sr 72 Kr β + λ pp vs. λ β? Xe (54) I (53) Te (52)

41 ISOLTRAP Exp. masses of 72 Kr, 73 Kr and 74 Kr + masses for 73 Rb and 74 Sr from :. Delay in rp-process > 80 % of T 1/2 72 Kr strong waiting point

42 32 S beam impinging on 54 Fe or nat Ni target 12 Q EC and S p values were improved ( Y, 83-86,88 Zr and Nb) Mass of 84 Zr for the first time as well S p -energies of 84 Zr and 85 Nb. Mass excesses of Nb-isotopes Proton separation energies S p (AME)-S p (exp.) [kev] JYFLTRAP AME Y 81Y 82Y 83Y 83Zr 84Zr 85Zr 86Zr 88Zr 85Nb 86Nb 87Nb 88Nb Large deviations compared to compiled values [AME2003], which are based on the beta-endpoint measurements. Large discrepancies for for Nb-isotopes Need to revise S p -values, and thus the location of the rp-process path A. Kankainen, EPJA 29 (2006) 271

43 Endpoint of of the rp-process SnSbTe cycle Possible seed nucleus 106 Cd Path beyond the SnSbTe cycle depends on the mass of 111 I, which can be determined from the mass of 107 Sb Cd (48) Sn (50) In (49) Te (52) Sb (51) Cs (55) Xe (54) I (53) N Ni+ 58 Ni Dec-2008 JYFLTRAP

44 New New data: data: SHIPTRAP and and JYFLTRAP N=Z stable nucleus JYFLTRAP 2007 JYFLTRAP 2006 JYFLTRAP 2005 Half-life > 10 ms Mass precision > 10 kev Half-life > 10 ms Unknown mass Ru (44) Rh (45) Pd (46) Ag (47) Cd (48) In (49) Sn (50) Xe (54) I (53) Te (52) Sb (51) Nb (41) Mo (42) Tc (43) Y (39) Zr (40) Sr (38) N

45 J. Pruet et al., Astrophys.J. 644 (2006) T = S p from AME95 extrapolation For example 80 Y, 88 Tc and 90 Ru already measured at JYFLTRAP! νp-process path Newly proposed nucleosynthesis process for neutron-deficient nuclei with A>64 C. Fröhlich et al., Phys. Rev. Lett. 96, (2006) Neutrons are created in the p-rich matter by antineutriino absorption Neutrons are captured (n,p) reaction mimic betadecay, but it is much faster Quick bypassing of rpprocess waiting points

46 92 Ru(p,γ) 93 Rh(p,γ) 94 Pd 92 Mo 94 Mo Prediction: S p = 1.64±0.1 MeV JYFLTRAP: S p =2.001±0.007 MeV

47 Atomic mass measurements of of n-rich radioisotopes Z Much more to come!!! N T=1.5 GK, N n =10 24 /cm 3 T=1.0 GK, N n =10 28 /cm Astrophysics motivation: Location of r-process path, which in the 1st approximation proceeds along the path where the neutron-capture and photodisintegration are in balance. λ γn T N 3 2 n e S n =2-4 MeV Sn kbt λ nγ

48 Mass predictions and r-process abundances R-process R-process abundances abundances calculated calculated with with the the HFBCS-1, HFBCS-1, ETFSI-2 ETFSI-2 and and FRDM FRDM mass mass models models in in the the framework framework of of the the canonical canonical model. model. The r-process is characterized by N The r-process is characterized by N n = 10 n = cm cm 3 3, T = , T = K and τ = 2.1 s. K and τ = 2.1 s. S.Goriely, Hyperfine interactions 132 (2001) 105