Download presentation
Presentation is loading. Please wait.
Published byArlene Fleming Modified over 8 years ago
1
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Nuclear structure probed by precision atomic mass measurements in a Penning trap Ari Jokinen Department of Physics University of Jyväskylä
2
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL (Short) introduction M(Z,N) = Mm n + Zm p + B(Z,N) contains all information of the structure of the nucleus Weak interaction studies and fundamental physics: (0+ 0+, -physics, , part.-antipart., …) Sub-keV precision of less exotic nuclei: Data from dedicated experiments with stable isotopes and reaction Q-values Nuclear structure and nuclear astrophysics: Atomic masses of exotic isotopes with 1-100 keV precision: Usually based on the decay studies (Q , Q , …), extrapolations and interpolations (AME) and mass predictions
3
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Penning trap (and storage ring) era Access to Direct mass measurements of short-lived and rare isotopes with improved precision ! ATOMIC MASSES for nuclear physics: - benchmark mass predictions and nuclear structure theories - input for improved predictions far from stability BINDING ENERGIES and their DIFFERENCES over long chains of isotopes provide experimental information and verification: - evolution of nuclear structure - evolution shell gaps - pairing correlations - …
4
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL JYFLTRAP setup at IGISOL 1) K130 accelerator: I p ~ 50 A and E p ~ 20-70 MeV) HI-ions up to 132 Xe (~5 MeV/u) Plenty of on-line time (K130 beam-on-target 7000 h/year) 1 3) Spectroscopic information: Access to complementary information of nuclear structure vie decay spectroscopy and collinear laser spectroscopy 3 3 3 4) JYFLTRAP: Combination of RFQ cooler.buncher and Tandem Penning trap located in 7T superconducting solenoid: - M/ M purification 1-2 x 10 5 - Precision mass measurement applying TOF - Few keV precision for NS studies - 8 x 10 -9 precision for Q EC - 62 Ga, T 1/2 =116ms, +/- 540 eV, 1.8 x 10 -8 4 2) Ion Guide ISOL: LI-IG, HI-IG, fission IG Chemically inselective Fast (ms-regime) 1+ DC-beam at 30 keV with M/ M ~300 2 MASS MEASUREMENTS WITH JYFLTRAP
5
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Critical survey of AME and previous data; Nb U. Hager et al., NPA 793 ( 2007) 20 A. Kankainen et al., EPJA 29 (2006) 271
6
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL JYFLTRAP data vs. AME 2003 N-def. A~100 0+ 0+ N-rich A~100
7
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Mass predictions vs. JYFLTRAP data U. Hager et al., NPA 793 ( 2007) 20 1. Tendency: Mass predictions and AME deviate from new precise data, but they often agree with each other ! Are predictions guided (too much) by AME ? 2. Plenty of new data and more is coming, but AME update will take years model benchmarking and adjustment should be based on the experimental data !
8
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Binding energies in transitional region A~100 20406080 0 Quadrupole deformation 2 of even-even nuclei HFB + THO + LN M.V. Stoitsov et al., Phys. Rev. C 68 (2003) 054312 2 < -0.2 -0.2 - -0.1 -0.1 - +0.1 -0.1 - +0.2 +0.2 - +0.3 +0.3 - +0.4 > + 0.4 Shape changes Shell gaps and sub-shell closures
9
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Two-neutron separation energies from Ni to Pd
10
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Two-neutron separation energies from Tc to Pd
11
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Two-proton separation energies below 100 Sn New data removes some of irregularities in the existing old data compiled in AME ! Liquid-drop behaviour
12
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Discontinuity at N~60, Z~40
13
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL 2 =0.0 2 =0.3 2 =0.4 Observed discontinuity appears in expected region of rapid changes of deformation and agrees perfectly with the recent collinear laser spectroscopy data Discontinuity at N~60, Z~40 – shape effect
14
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL N=50 shell gap
15
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL N=50 shell gap extracted from AME2003 ?
16
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL N=50 shell gap from AME2003+Penning trap data
17
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL J.M. Pearson and S. Goriely, Nucl. Phys. A 777 (2006) 623-644 Z=28 Shell gap energies – predictions 2n (N o ) = S 2n (N o )-S 2n (N o +2)
18
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Pairing OES of nuclear binding energies pairing-gap energy in the standard BCS theory Differences measured masses n or p G = strength of the pairing interaction = single-particle energy = chemical potential Bohr-Mottelson n = 12/A 1/2 [MeV], fixed Z Bohr-Mottelson n = 12/A 1/2 [MeV], fixed A D.G. Madland and J.R. Nix, NPA476 (1988) 1 n = 5.7 exp(0.12I-8I 2 )/N 1/3 [MeV] P. Vogel, B. Jonson and P.G. Hansen, PL 139B (1984) 227 n = (7.4-45I 2 )/A 1/3 [MeV] 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 2
19
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Pairing energies; close look as f(N) 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 2 Connection to: in BCS-theory ? Pairing functional ???
20
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Proton-neutron pairing energies for o-o N=Z nuclei LEBIT, MSU (G. Bollen): Precise mass measurements of short-lived Ge, As and Se isotopes close to N=Z=33. Vanishing of Wigner energy while approaching 100 Sn ? P. Schury et al., PRC75 (2007) 055801 Indication of re-strengthening of V np – to be verified by further mass measurements !
21
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Summary and outlook ISOLTRAP, JYFLTRAP, LEBIT, SHIPTRAP, CPT and TITAN: 600 isotopes with keV-range precision and more to come … ESR for the shortest half-lives and the most exotic cases with limited accuracy
22
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL Precise direct masses of exotic isotopes: Deficiencies in existing data set far from stability Faults in AME compilation Misguidance of atomic mass predictions and other models trying to reproduce AME mass surface Differences of atomic masses with keV-range accuracy: Variations in two-particle separation energies reflects underlying nuclear structure Evolution of shell gaps Pairing gaps Proton-neutron pairing energies …
23
FIDIPRO-JSPS Workshop, Keurusselkä 25-27.10.2007, AriJokinen, JYFL V.-V. Elomaa T. Eronen U. Hager J. Hakala A. Jokinen A. Kankainen P. Karvonen T. Kessler I. Moore H. Penttilä S. Rahaman S. Rinta-Antila J. Rissanen J. Ronkainen A. Saastamoinen T. Sonoda C. Weber J. Äystö Department of Physics, P.O.Box 35 (YFL) FIN-40014 University of Jyväskylä Acknowledgements:
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.