Speaker
Philippos Papadakis
(University of Jyvaskyla)
Description
In-beam spectroscopic techniques have long been one of the most prominent tools in our effort to
disentangle and interpret complex nuclear structure phenomena. In heavy nuclei, where internal
conversion increasingly competes with γ-ray emission, the simultaneous study of γ rays and
conversion electrons can provide a much more complete image than either of them
independently.
The SPEDE spectrometer [1] aims to combine a silicon detector, for the detection of electrons,
with the MINIBALL γ-ray detection array for in-beam studies employing radioactive ion beams
at the HIE-ISOLDE facility at CERN. The setup will be primarily used for octupole collectivity
[2] and shape coexistence studies [3, 4] in Coulomb excitation experiments. In the shape
coexistence cases the transitions between states of the same spin and parity have enhanced E0
strength [5]. Additionally the 0+à0+ transitions, typically present in nuclei exhibiting shape
coexistence [6], can only occur via E0 transitions, i.e. via internal conversion electron emission.
SPEDE is one of the first attempts to combine in-beam γ-ray and conversion electron
spectroscopy with radioactive ion beams. This poster will present the current status of the setup.
References
[1] J. Pakarinen et al., Letter of Intent to the INTC for HIE-ISOLDE (2010).
[2] P.A Butler et al., Proposal to the INTC for HIE-ISOLDE (2012).
[3] K. Wrzosek-Lipska et al., Proposal to the INTC for HIE-ISOLDE (2012).
[4] J. Pakarinen et al., Proposal to the INTC for HIE-ISOLDE (2013).
[5] C.Y. Wu et al., Phys. Lett. B 541 (2002) 59.
[6] K. Heyde and J.L. Wood, Rev. Mod. Phys. 83 (2011) 1467.
Primary author
Philippos Papadakis
(University of Jyvaskyla)
