Embed Size (px)
DESCRIPTION
Coulomb Excitation of 140 Nd (and 140 Sm) Experiment IS496 MINIBALL@REX-ISOLDE. ENSAR. B(E2) of first 2 + state A twofold motivation. Systematics. Mixed-symmetry. Knowledge of B(E2) as basis for observation of mixed-symmetry state Future possibility with HIE-ISOLDE. A~140 region - PowerPoint PPT Presentation
Citation preview
Coulomb Excitation of Coulomb Excitation of 140140NdNd(and (and 140140Sm)Sm)
Experiment IS496Experiment IS496MINIBALL@REX-ISOLDEMINIBALL@REX-ISOLDE
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
ENSAR
B(E2) of first 2+ stateA twofold motivation
SystematicsA~140 regionN=80 isotonesComparison with QPM
Mixed-symmetryKnowledge of B(E2) as basis for observation of mixed-symmetry state
Future possibility with HIE-ISOLDE
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Experimental Setup01.07. – 04.07.2011
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Projectile: 140Nd Contaminant: 140Sm, ... ? Ion source: RILIS Current: I ~ 1-2 pA Ebeam = 399 MeV (2.85 MeV/u) Targets: 1. 48Ti (1.4 mg/cm2)
2. 64Zn (1.55 mg/cm2)
Principles of MeasurementTarget normalization
Unstable nuclei of interest provided as beam Normalization to well-known target excitation Choice of target
Excitation cross-section (depending on beam energy E, proton number Z and B(E2) value)
Kinematics (geometry, particle detector) Uncertainty of parameter for normalization
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
2+
0+
M20
M22
Particle identificationEnergy distribution over CD
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Cut on detectedscattered target nuclei
Gamma spectraDominated by 140Nd and 140Sm
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
140Sm531 keV
140Nd774 keV
48Ti984 keV
Laser onLaser off
Laser ON/OFF comparisonNormalized to 140Sm excitation
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Laser onLaser off
Laser ionisation+
Surface ionisation
140Nd774 keV
140Sm531 keV
Result of Coulex calculationsUsing CLX and DCY
Conditions Contaminants subtracted by
140Sm comparison Only excitation of first 2+
taken into account (projectile and target)
Normalization to target excitation of 48Ti
B(E2; ) = 30(5) W.u.
QPM value: 17 W.u.
Map of matrix elements
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
140Nd and isotopic chain
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
N=80 isotones
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Summary
Results 140Nd Coulex evaluation
B(E2) = 30(5) W.u. 140Sm Coulex limit
B(E2) < XXX W.u.
Conclusions B(E2) larger than expected
from various predicitions, need further interpretation
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
Outlook / To do Detailed analysis of 140Sm fraction
in beam composition
Handling of Coulex calculations with Gosia2
142Sm experiment in 2012?
First identification of a MSS in a radioactive isotope @HIE-ISOLDEin 2014/2015?
Thank you for your attention!
07.12.2011 | ISOLDE workshop | Christopher Bauer - TU Darmstadt
