[PPT] - Lifetime measurements with fast-timing arrays Ben Crider FRIB PowerPoint Presentation

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Ben Crider 1

Lifetime measurements with fast-timing arrays

Ben Crider FRIB Decay Workshop January 25-26, 2018

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Overview

Shell structure helps lay out a

roadmap of interesting structural features

Experimentally determined

properties described in terms

f shell structure
Large-scale shell model

calculations and ab initio calculations (NCSM, IM-SRG, and their merger) have exciting prospects as they move towards expanding our understanding of medium- mass nuclei

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Overview

Shell structure helps lay out a

roadmap of interesting structural features

Experimentally determined

properties described in terms

f shell structure
Large-scale shell model

calculations and ab initio calculations (NCSM, IM-SRG, and their merger) have exciting prospects as they move towards expanding our understanding of medium- mass nuclei

S. Mukhopadhyay et al, Phys. Rev. C 95, 014327 (2017)

76Ge

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Shell Evolution

Many shell model calculations predict a modified shell

structure in nuclei away from the 𝛾-stability line

T. Otsuka et al., Phys. Rev. Lett. 104, 012501 (2010)

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FRIB Nuclei

M. Thoennessen, Nuclear Data Sheets 118, 85 – 90 (2014)
FRIB will enable the study of

many exotic nuclei

Even for nuclei near the

extremes of the FRIB production rates, 𝛾-decay studies are a viable means for determining their low-lying properties

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Energy Systematics

Need to go beyond energy

systematics to measuring transition strengths and comparing with large-scale theoretical calculations

A. Gade and S. N. Liddick, J. Phys. G: Nucl. Part. Phys. 43 (2016) 024001.

28Ni (E0+/2) 27Co 29Cu

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Lifetimes around the nuclear chart

M. Thoennessen, Nuclear Data Sheets 118, 85 – 90 (2014)
A lot of useful information can

be determined through measuring lifetimes all throughout the nuclear chart

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Lifetimes of proton-rich nuclei

H. Mach et al., Phys. Rev. C 95, 014313 (2017)
M. Thoennessen, Nuclear Data Sheets 118, 85 – 90 (2014)

94Ru, 96Pd

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Lifetimes of neutron-rich nuclei

M. Thoennessen, Nuclear Data Sheets 118, 85 – 90 (2014)
S. Suchyta et al., Phys. Rev. C 89, 021301(R) (2014)

68Ni E(keV)

1603 2511 0+ 0+ 0+

68Ni

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68Ni 70Ni

1604 2511

0+ 0+ 0+

MCSM calculations also predict shape coexistence in 70Ni
Deepening of the prolate potential well

0+ 0+

1525

http://fustipen.ganil.fr/conferences/2014/workshops/underst anding-nuclear-structure-and-reactions-microscopically- including-the-continuum-2/talks/otsuka_fustipen.pdf

Predicted Shape Coexistence in 70Ni

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National Superconducting Cyclotron Laboratory

9Be target

A1900 Fragment Separator Cocktail beam A~68 delivered to experimental end-station

76Ge 130 MeV/u

primary beam Coupled Cyclotron Facility at NSCL

Fragmentation of a fast-moving, heavy, stable beam on a thin stable target

76Ge beam at ~130 MeV/A
282 µg/cm2 9Be target

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N. Larson et al., Nucl. Instrum. Methods Phys. Res. A 727, 59 (2013)
C. J. Prokop, et al., Nucl. Instrum. Methods Phys. Res. A 741, 163 (2014)
Use beta decay to populate excited states of exotic

nuclei near A = 68

Combine detection systems to simultaneously

achieve fast timing information and high- resolution energy measurements

Central Implantation Detectors: Implanted ions from beam and beta decays

M. Alshudifat et al., Physics

Procedia 66, 445 (2015).

NSCL Experiment: Detection Systems

Ions identified event-by- event are implanted. Position and arrival time recorded for all implanted ions Some characteristic time later a decay is

detected. Position

and time of decay recorded.

Decays are correlated to ions using spatial and

temporal information

Time scales: Beta decay: ~10-3 s, Gamma decay:

~10-15 to 10-9 s

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Ben Crider 13 Half of 16 HPGe SeGA array LaBr3(Ce) array Gamma-ray Detectors

N. Larson et al., Nucl. Instrum. Methods Phys. Res. A 727, 59 (2013)
C. J. Prokop, et al., Nucl. Instrum. Methods Phys. Res. A 741, 163 (2014)
W. Mueller et al., Nucl. Instrum. Methods Phys. Res. A 466, 492 (2001)

Central Implantation Detectors: Implanted ions from beam and beta decays

M. Alshudifat et al., Physics

Procedia 66, 445 (2015).

Time (~ps or ~ns) g1 or b g2 Dt related to T1/2

NSCL Experiment: Detection Systems

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Lifetime Results

B.P. Crider, C.J. Prokop, S.N. Liddick et al., (in prep.)

68Cu 68Zn

β-

1077.4-keV γ ray

2+ 0+ 1077.4

1.61 ps

B. P. Crider et al., Phys. Lett. B 763, 108 (2016).

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Lifetime Results

70Co 70Ni

β-

448-keV γ ray

6+ 4+ 2677 2229

1.05(3) ns [1]

B. P. Crider et al., Phys. Lett. B 763, 108 (2016)
H. Mach et al., Nucl. Phys. A 719, C213 (2003)

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Lifetime Results

Correlated decays into 70Ni

Time (ns) Energy (keV) Counts / 1 keV Energy (keV)

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Lifetime Results

478 keV

B. P. Crider et al., Phys. Lett. B 763, 108 (2016)

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Lifetime Results

307 keV

B. P. Crider et al., Phys. Lett. B 763, 108 (2016)

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Putting it all together for 68,70Ni…

S. Suchyta et al., Phys. Rev. C 89, 021301(R) (2014).

http://fustipen.ganil.fr/conferences/2014/workshops/understanding- nuclear-structure-and-reactions-microscopically-including-the- continuum-2/talks/otsuka_fustipen.pdf

B. P. Crider et al., Phys. Lett. B 763, 108 (2016)
S. M. Lenzi et al., Phys. Rev. C 82, 054301 (2010)
Y. Tsunoda et al., Phys. Rev. C 89, 031301 (2014)

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Putting it all together for 68,70Ni…

S. Suchyta et al., Phys. Rev. C 89, 021301(R) (2014).

http://fustipen.ganil.fr/conferences/2014/workshops/understanding- nuclear-structure-and-reactions-microscopically-including-the- continuum-2/talks/otsuka_fustipen.pdf

B. P. Crider et al., Phys. Lett. B 763, 108 (2016)
S. M. Lenzi et al., Phys. Rev. C 82, 054301 (2010)
Y. Tsunoda et al., Phys. Rev. C 89, 031301 (2014)

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Lifetime of the 02

+ in 68Ni

C.J. Prokop, B.P. Crider, S.N. Liddick et al., (in prep.)

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Conclusions

FRIB opens up a large number of nuclei for which 𝛾-decay

experiments can provide many details on their low-lying structure

Lifetime measurements leading to transition strength

determinations are critical for understanding the underlying configurations of excited nuclear states.

A recent experiment at NSCL coupling fast-timing and high-

resolution detection systems has enabled an expansion of the information in 68,70Ni.

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Acknowledgements

Collaborators NSCL: S. N. Liddick, C. J. Prokop, J. Chen, A. C. Dombos, N. Larson, R. Lewis,

S. J. Quinn, and A. Spyrou,

ANL: A. D. Ayangeakaa, M. P. Carpenter, H. M. David, R. V. F. Janssens, T. Lauritsen, D. Seweryniak, and S. Zhu. ARL: J. J. Carroll and C. J. Chiara UMD: J. Harker and W. B. Walters Padova: F. Recchia UTK: M. Alshudifat, S. Go, R. Grzywacz LBL: S. Suchyta Funding This work was supported in part by the National Science Foundation (NSF) under Contract No. PHY-1102511 (NSCL) and Grant No. PHY-1350234 (CAREER), by the Department of Energy National Nuclear Security Administration (NNSA) under Award No. DE-NA0000979 and Grant No. DE- NA0002132, by the U.S Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC-06CH11357 (ANL) and Grant Nos. DE-FG02- 94ER40834 (Maryland) and DE-FG02-96ER40983 (UT), and by the U.S. Army Research Laboratory under Cooperative Agreement W911NF-12-2-0019.