LEAP, Kanazawa, Japan 2016

Transcription

1 LEAP, Kanazawa, Japan 2016 Precision atomic and nuclear masses and their importance for nuclear structure, astrophysics and fundamental studies Motivation for precision mass data Storage ring/penning-trap mass spectrometry Applications of atomic/nuclear masses Klaus Blaum March 9 th, 2016

2 Characteristics of a nucleus its weight its size its life-time/decay its shape its e.m. property its mood (state) Unique tools have been developed to determine experimentally and to describe theoretically these characteristics.

3 Fields of applications nuclear structure, nuclear forces (nuclear) astrophysics, astrochemistry, production of heavy elements, atomic and molecular binding energies H 2 particle fundamental interactions and their symmetries, fundamental constants antiparticle C 60 P C T Adapted from H. Wilschut

4 Why measuring atomic masses? Relative mass precision of 10-9 and below can presently ONLY be reached by Penning-trap mass spectrometry.

5 Atomic and nuclear masses Masses determine the atomic and nuclear binding energies reflecting all forces in the atom/nucleus. = N + Z + Z binding energy M Atom = N m neutron + Z m proton + Z m electron - (B atom + B nucleus )/c 2 δm/m < δm/m =

6 How to weigh an atom ν c,2 ν c,1 ν c,1 ν c,2

7 Storage and cooling techniques Penning trap Storage ring Quadrupoletriplet Dipole magnet From the FRS Septummagnet Hexapolemagnets To the SIS Schottky pick-ups Gas-target Electron cooler Fast kicker magnet Extraction z 0 r0 ESR Quadrupoledublet RF-Accelerating cavity cm K. Blaum, Physics Reports 425 (2006) m B. Franzke, H. Geissel & G. Münzenberg, Mass Spectrometry Reviews 27 (2008) 428 particles at nearly rest in space relativistic particles ion cooling (buffer gas, resistive, electron) long storage times single-ion sensitivity high accuracy

8 Storage of ions in a Penning trap B Ion q/m U Charge q Mass m The free cyclotron frequency is inverse proportional to the mass of the ions! An invariance theorem saves the day: L.S. Brown, G. Gabrielse, Rev. Mod. Phys. 58, 233 (1986). ωc = qb / m ω c 2 = ω +2 +ω -2 +ω z 2 ω c = ω + + ω -

9 Detection techniques Destructive time-of-flight detection 7 T 0 R 1/T obs δm/m 10-9 Destructive phase-imaging detection 7 T 0 R 1/T obs φ/2π δm/m S. Eliseev et al., Phys. Rev. Lett. 110, (2013) Non-destructive induced image current detection δm/m K

10 A Penning-trap setup In collaboration with W. Nörtershäuser (TUD) and Ch. Düllmann (UMz).

11 Masses and radii Nuclear structure studies GSI, IMP, ANL, IGISOL, ISOLDE, NSCL, TRIGA, TRIUMF

12 Nuclear structure studies S 2n = B nucl (Z,N) B nucl (Z,N-2) N = 126 shell closure deformation 214 Pb 229 Rn 233 Fr M Atom = N m neutron + Z m proton + Z m electron - (B atom + B nucleus )/c 2

13 Ca masses pin down nuclear forces Multi-reflection time-of-flight and Penning-trap mass spectrometry 51,52 Ca B 53,54 Ca R. Wolf et al., Int. J. Mass Spec. 349, 123 (2013) T. Dickel et al., Nucl. Instrum. Meth. B 317, 779 (2013) Production rates of ~10 ions/s N = 28 magic number Mass measurements via S 2n establish new magic number at N = 32 Correct prediction from 3N-forces (A. Schwenk et al., TUD) F. Wienholtz et al., Nature 498, 346 (2013) ISOLTRAP (CERN), TITAN (TRIUMF) PRL 114, (2015) N=31,32 TITAN Z=20 Ca N = 32 magic number

14 Masses Nuclear astrophysics studies CPT, CSRe, ESR, ISOLTRAP, JYFLTRAP, LEBIT, SHIPTRAP, TITAN

15 Mass spectrometry for nucleosynthesis Nuclear masses (binding energies) determine the paths of the processes. Can be addressed at FAIR

16 Nuclear astrophysics Composition of the outer crust of a neutron star (T 1/2 ~ 200ms) 80 ions in δm/m ~ minutes! δm/m = 4 10 (< 1-8 kev) R. Wolf et al., Phys. Rev. Lett., 110, (2013)

17 Weak interaction studies Test of the unitarity of the CKM quark mixing matrix Weak Interaction Radioactive decay Strong Interaction Binding between quarks within hadrons 1 0 n 1 1 p + e + ν e

18 Q EC values of superallowed beta emitters Superallowed beta emitters? Decays of nuclear states, T=1 Pure Fermi decays Simple decay matrix element Characterized with an ft value f stat. rate function;(f Q EC5 ) t partial half-life t 1/2 /b Q-values needed at 100-eV level

19 Testing the Standard Model Corrected value: Corrections about 1% [Towner and Hardy, Phys. Rev. C 77, (2008)] Cabibbo-Kobayashi-Maskawa quark mixing matrix Quark-mass eigenstates to weak eigenstates Currently transitions contribute

20 Superallowed beta-emitters Q EC Contributes to world average value (13) 14 of them contribute to the world average value. JYFLTRAP (IGISOL) ISOLTRAP (ISOLDE) CPT (Argonne) LEBIT (MSU) TITAN (TRIUMF) More exciting results from CSRe in Lanzhou are coming soon.

21 The Ft picture Ft = (72) s Hardy&Towner, Phys. Rev. C 91 (2015)

22 Test of the CKM unitarity Check unitarity via first row elements: V ud 2 + V us 2 + V ub = 1 + Δ V us and V ub from particle physics data (K and B meson decays) 2 Unitarity contribution: V ub V us 0.001% 5% V ud (nuclear β-decay) = (21) V us (kaon-decay) = (14) V ub (B meson decay) = (5) V Present status: ud + Vus + Vub = (55) 0,9999(6) V ud 95% Hardy&Towner, Phys. Rev. C 91 (2015)

23 Towards highest precision Nuclear masses for tests of fundamental symmetries FSU, ISOLTRAP, JYFLTRAP, SHIPTRAP, THe-TRAP, TRIGATRAP

24 THe-TRAP for KATRIN A high-precision Q( 3 T- 3 He)-value measurement 3 1 H 3 He 2 + e +ν Q lit = (1.2) ev Q lit = (7) ev [E. Myers, PRL (2015)] We aim for: δq( 3 T 3 He) = 20 mev δm/m = T < 0.2 K/d at 24 C B/B < 100 ppt / h x 0.1 µm First 12 C 4+ / 16 O 6+ mass ratio measurement at δm/m = performed.

25 The ECHo ( 163 Ho) project Metallic Magnetic Calorimetry Q-value of EC in 163 Ho Our result Status in 2014 Q-value with δq<1 ev S. Eliseev et al., PRL (2015)

26 Most stringent baryonic CPT test Compare charge-to-mass ratios R of p and p See talk by Andreas Mooser

27 Summary Exciting results in high-precision mass spectrometry with stored and cooled exotic ions! Thank you for the invitation and your attention! WWW: Max Planck Society IMPRS-PTFS Adv. Grant MEFUCO Helmholtz Alliance