MPI fr Physik, Mnchen 2015 Nuclear Ground State Properties and their - - PowerPoint PPT Presentation
MPI fr Physik, Mnchen 2015 Nuclear Ground State Properties and their Importance for Nuclear Structure, Nuclear Astrophysics and Fundamental Studies. Motivation for precision nuclear data Atomic physics techniques in nuclear physics
Klaus.blaum@mpi-hd.mpg.de
In recent years unique tools have been developed to determine experimentally and to describe theoretically these characteristics.
Spins, Moments
microscopic nuclear structure: wave functions, coupling of nucleons, configuration mixing, shell structure macroscopic nuclear structure: deformation
Charge Radii
nuclear structure: nuclear charge distribution, deformation
Masses
nuclear binding energy basic test of nuclear models nuclear structure: shell closures, magic numbers, pairing, onset of deformation, drip lines, halos
= N · – binding energy + Z · + Z ·
Masses determine the atomic and nuclear binding energies reflecting all forces in the atom/nucleus.
δm/m < 10-10 δm/m = 10-6 – 10-8
Ion q/m Charge q Mass m
B
c
L.S. Brown, G. Gabrielse, Rev. Mod. Phys. 58, 233 (1986).
2 = ω+ 2+ω- 2+ωz 2
+ ω-
An invariance theorem saves the day:
Destructive time-of-flight detection Space/ Phase resolving detection R ∝ 1/Tobs R ∝ 1/Tobs ∙ ∆φ/2π
Number of detected ions
In collaboration with W. Nörtershäuser (TUD) and Ch. Düllmann (UMz).
Isotope 1 Isotope 2 Isotope Shift := Frequency difference in an electronic transition between two isotopes
Isotope Shift Hyperfine Structure
2
r M
electrostatic deflection photo multiplier
+ + +
Ekin<60 keV
laser beam
fixed frequency
electrostatic lenses for retardation charge exchange cell (Na) excitation & observation reg.
250
25
Mg HFS of
A(S1/2) = 596.5(5) MHz
300 350 fine Doppler tuning voltage (V) 250 400
photons
∆
25 Mg
HFS of
6.5
~ 106 -107 11Be+/s T1/2 = 13.6 s
ESR, ISOLTRAP, SHIPTRAP, TITAN
Production rates of ~10 ions/s Mass measurements via S2n establish new magic number at N = 32 Correct prediction from 3N-forces (A. Schwenk et al., TUD)
Multi-reflection time-of-flight and Penning-trap mass spectrometry
53,54Ca
ISOLTRAP (CERN), TITAN (TRIUMF)
B
51,52Ca
Z=20 Ca N=31,32 TITAN
N = 28 magic number N = 32 magic number
11Be
10Be
3/2 - 0 keV 375 keV
9Li +2n
11Li
11Li 207Pb
large matter radius weakly bound
characteristic properties of nuclear halos
probing halo neutron – nucleus interaction
increased charge radius
rc
9
rc
11 =
?
T1/2 [s] 13.6 0.02 Yield [s-1] 7×106 1×103
12Be 11Be
7Be 7Be 8Be 8Be 9Be 9Be 10Be 10Be 11Be 11Be 11Be
7.7 fm
11Be 11Be
7.7 fm
CPT, CSRe, ESR, ISOLTRAP, JYFLTRAP, LEBIT, SHIPTRAP, TITAN
Nuclear masses (binding energies) determine the paths of the processes.
δm/m ~ 10-8 (< 1 keV)
(T1/2 ~ 200ms)
MNRAS.426.1940 (γ,n) photo- disintegration equilibrium favours “waiting point”
β-decay
seed
rapid neutron capture
N Z
Mismatch comes from:
correct. Need nuclear physics experiments & theory for predictions!
FSU, ISOLTRAP, JYFLTRAP, SHIPTRAP, THe-TRAP, TRIGATRAP
very small signal ~fA ion signal Amplitude mass/frequency spectrum
„FT-ICR“ Fourier-Transform- Ion Cyclotron Resonance
Qlit =18 589.8 (1.2) eV
ν + + →
−
e He H
3 2 3 1
We aim for: δQ(3T3He) = 20 meV δm/m = 7·10-12
∆T < 0.2 K/d at 24°C ∆B/B < 100 ppt / h ∆x ≤ 0.1 µm First 12C4+/16O6+ mass ratio measurement at δm/m = 1.4∙10-11 performed.
Qlit =18 592.01(7) eV [E. Myers, PRL (2015)]
Metallic Magnetic Calorimetry Q-value with δQ<1 eV
Status in 2014
Exciting results in high-precision mass spectrometry / laser spectroscopy with stored and cooled exotic ions!
Email: klaus.blaum@mpi-hd.mpg.de WWW: www.mpi-hd.mpg.de/blaum/
Max Planck Society
Helmholtz Alliance IMPRS-PTFS