Measuring octupole collectivity in 221 Rn using Coulomb excitation at MINIBALL, & SPEDE
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Measuring octupole collectivity in 221 Rn using Coulomb excitation at MINIBALL, & SPEDE George O’Neill
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Measuring octupole collectivity in 221 Rn using Coulomb excitation at MINIBALL, & SPEDE. George O’Neill. Octupole collectivity. Certain nucleon configurations have reflection asymmetry Enhanced Schiff moments due to nearly degenerate parity doublets Induce atomic electric-dipole moments - PowerPoint PPT Presentation
Transcript of Measuring octupole collectivity in 221 Rn using Coulomb excitation at MINIBALL, & SPEDE
Measuring octupole collectivity in 221Rn using Coulomb excitation at MINIBALL, & SPEDE
George O’Neill
Octupole collectivityCertain nucleon configurations have reflection asymmetryEnhanced Schiff moments due to nearly degenerate parity doubletsInduce atomic electric-dipole momentsOctupole moment measured through E3 transition
[1] ‘Octupole collectivity in 220Rn and 224Ra’, L. Gaffney, PhD thesis, 2012
221-RadonParity doublet splitting only possible in odd mass systems [2]Theoretically, asymmetry strongest @ Z=88, N=134Good beam achievable at ISOLDEInternal conversion dominates some transitions vs gamma decay
221Rn, 1x105 ion/s48 hour beam time120Sn target, 2 mg/cm2
REX-ISOLDERadioactive ion beam – Radioactive beam EXperiment at ISOLDEProtons incident on UCX targetAccelerates up to 3.0 MeV/u
MINIBALLCoulomb excitationGamma detector array with DSSSD144 segments of encapsulated GeCurrently offline for HIE-ISOLDE upgrade
Results so far
201.0 ↓
223.5 ↓
289.3 ↓
Kβ1
↓
Kα1, Kα2
↓
221Rn, 6x103 ion/s30 hour beam time120Sn target, 2 mg/cm2
Results so far
201.0 ↓
223.5 ↓
289.3 ↓
Kβ1
↓
Kα1, Kα2
↓
7/2+, 0 keV
223.5 keV
22.5 keV7/2+, 0 keV
201.0 keV 223.5 keV
SPEDE - motivationSPectrometer for Electron DEtectionSi detector in backwards geometryAllows full pictureCan also be used for other useful physics
SPEDE – where we areBeam time applied for at JYFLDetector orderedPreamplifiers testedOn track for installation Q4 2014
SummarySome initial results for 221RnSPEDE will enhance knowledge of nucleusShould have first results by 2015
1. ‘Octupole collectivity in 220Rn and 224Ra’, L. Gaffney, PhD thesis, 20122. ‘Reflection-asymmetric shapes in odd-A actinide nuclei’, Nucl. Phys. A529
(1991), S. Ćwiok, W. Nazarewicz3. ‘Combined in–beam γ–ray and conversion electron spectroscopy with
radioactive ion beams’, P. Papadakis, J. Pakarinen (JYFL proposal)
221Rn CollaborationCEA
Dr Marie-Delphine Salsac, Dr Magda Zielinska
Technischen Universität DarmstadtProf Thorsten Kröll, Dr Marcus Scheck, Sabine Bönig, Michael Thürauf
University of FloridaProf C.Y. Wu
University of JyväskyläDr Tuomas Grahn, Joonas Konki, Sanna Stolze
University of CologneDr Nigel Warr, Lars Lewandowski, Burkhard Siebeck, Tim Steinbach, Andreas Vogt
KVI GroningenDr Lorenz Willman
KU LeuvenDr Liam Gaffney, Dr Kasia Wrzosek-Lipska, Tim De Coster, Nele Kesteloot
University of LiverpoolProf Peter Butler, George O'Neill
University of MichiganProf Tim Chupp
Yale UniversityDr Christian Bernards
SummarySome initial results for 221RnSPEDE will enhance knowledge of nucleusShould have first results by 2015
1. ‘Octupole collectivity in 220Rn and 224Ra’, L. Gaffney, PhD thesis, 20122. ‘Reflection-asymmetric shapes in odd-A actinide nuclei’, Nucl. Phys. A529
(1991), S. Ćwiok, W. Nazarewicz3. ‘Combined in–beam γ–ray and conversion electron spectroscopy with
radioactive ion beams’, P. Papadakis, J. Pakarinen (JYFL proposal)
