Upload
thomas-glass
View
219
Download
1
Embed Size (px)
Citation preview
Institut für Kernphysik, TU Darmstadt
K.-H. Speidel
Kernstrukturuntersuchungen an
radioaktiven Isotopen mit Hilfe von
-Transfer-Reaktionen
University of Surrey
DPG Spring Meeting 2008Darmstadt
J. Leske1
Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn
S. Pietri
GSI, Darmstadt
P. Doornenbal, J. Gerl, N. Goel, I. Kojouharov, W. Prokopowicz,
H. Schaffner, H.-J. Wollersheim
University of LUNDJ. Cederkall, A. Ekstroem
FZ RossendorfR. Schwengner
TU MünchenR. Gernhäuser, P. Maier-Komor
A. Jungclaus, J. Walker, V. ModamioUniversidad Autonoma de Madrid
1Institut für Kernphysik, TU DarmstadtB. Alikhani, L. Coquard, T. Bloch, N. Pietralla
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
need for radioactive ion beam facilities
Introduction & Motivation
exploration of the entire nuclear landscape
pn interaction
nn force
nuclear models
RIBF @ RIKEN (Japan)
NSCL @ MSU (USA)
ISAC @ TRIUMF (Canada)
SPIRAL2 @ GANIL (France)
REX-ILSOLDE @ CERN (Europe)
RISING @ GSI
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
Transient magnetic fields
linear parametrisation with
ion beam induced attenuation
exp = Gbeam
lin g
polarized electrons and aligned nuclear spin
excited ion with aligned nuclear spin travels through polarized ferromagnetic environment
empirical parametrization required !
stable beam
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
g-factor measurements using transfer
Particle coincidence
spectrum
Particle-- angular correlation
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
Particle gated -coincidence spectra
two different nuclei studied simultaneouslyrates comparable those of Coulex experiments
transfer selective to low spin states
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
g factors and B(E2)‘s from -transfer experiments
Ge68
32 36Zn62
30 32Ti44
22 22Ti52
22 30
O. Kenn et al., Phys. Rev. C65 (2002) 034308
J. Leske et al., Phys. Rev. C71 (2005) 044316
K.-H. Speidel et al., Phys. Lett. B 633 (2006) 219
S. Schielke et al., Phys. Lett. B 567 (2003) 153
T1/2 = 9.2 h T1/2 = 271 d
T1/2 = 1.7 m
T1/2 = 60 y
Is transfer also applicable for isotopes heavier than A = 68 ?
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
UNILAC Experiment U234 (see also HK 48.7 from J. Walker)
“Measurement of the g-factors of 2+ states in stable A=112,114,116 Sn isotopes using the transient field technique”
recoil detection20° 45°
4 Euroball Cluster at ±65°
112,114,116Sn@ 4 MeV/u
natC
Gd Cu
0.7 10.8mg/cm2
4.9
excitation layer natural carbon
112,114,116Sn + 12C112,114,116Sn*116,118,120Te*
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
UNILAC Experiment U234
400 600 800 1000 1200 14000
5000
10000
15000
0
2000
4000
6000
118Te
114Sn
Prompt particle gated -ray spectra
500 1000 1500 2000 2500 30000
5000
10000
15000
20000
25000
12C
Si spectrum
channel
coun
ts
E (keV)
coun
ts
51o
65o
79o
4+ →
2+
2+ →
0+
3- → 2
+
5- → 4
+
e- e+
2+ →
0+
4+ →
2+
2 2+ →
2+
e- e+
6+ →
4+
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
spectra
200 400 600 800 1000 1200 14000
2000
4000
60000
2000
4000
0
1000
2000
3000
E (keV)
coun
ts
112Sn/116Te
114Sn/118Te
116Sn/120Te e- e+
e- e+
e- e+
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
Experimental Result (preliminary)
PRELIMINARY
g(2 ) factors in 116,118,120Te+1 lifetimes from DSAM
analysis in 116,118,120Te
P. Raghavan, At. Data Tables 42, 189 (1989)
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
Summary
Beam :Isotope :
T1/2 :
78Kr82Sr44
86Kr90Sr52
84Sr88Zr48
124Xe128Ba72
136Xe140Ba84
96Ru100Pd54
3.6 d25.5 d 28.5 y 83.4 d 2.4 d 12.8 d
Transfer to stable Ion Beams (examples)
Transfer observed in nuclei beyond A ~ 110Proof of principle for g-factor and DSAM experiments using transfer to stable nuclei in a mass region between 32 < A < 116
More exotic nuclei by Transfer to radioactive Ion Beams !
Institut für Kernphysik, TU Darmstadt
Kernstrukturuntersuchungen an radioaktiven Isotopen mit Kernstrukturuntersuchungen an radioaktiven Isotopen mit -Transfer -Transfer
Outlook
Plunger Experiments
Precision lifetime study in the proton-rich 100Pd following Coulomb-barrier -transfer reactions on 96Ru
Precision lifetime study in the neutron-rich 140Ba following Coulomb-barrier -transfer reactions on 136Xe
1 symmetric cluster (prototype)
4 asymmetric cluster
36-fold segmented Ge cristalls
540 segments, 555 channels (digital)
photopeak efficiency 3 – 8 %
AGATA-Demonstrator (Legnaro)
Transient Field & DSAM Experiments
UNILAC (GSI), Legnaro, REX-ISOLDE, GANIL