2019-02-16

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Decay Spectroscopy of 160Eu Using the GRIFFIN Spectrometer

Daniel YatesUniversity of British Columbia/TRIUMF

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Nuclear Shell Model

§Describes energies and wave functions of nucleons§Closed shells at certain nucleon

number

R.F Casten. Nuclear Structure from a Simple Perspective (1990).

Energy

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Nuclear Structure

P. Möller et al., Atomic Nuclear Data Tables, 109-110 (2016).

spherical

deformed

§Deformed nuclei away from shell closures§ Investigate nuclei in regions of deformation

§ Improve theoretical models

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Nuclear Structure§Deformed nuclei away from shell closures§ Investigate nuclei in regions of deformation

§ Improve theoretical models

Nucleardata.nuclear.lu.seP. Möller et al., Atomic Nuclear Data Tables, 109-110 (2016).

160Eu !-decay to 160Gd

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Previous Work on 160Eu → 160Gd§Disagreeing results from 1973

J.M. D’Auria et al., Can. J. Phys. 51, 686 (1973). N.A. Morcos et al., J. Inorg. Nucl. Chem. 35, 3659 (1973).

*

*

*

*

**

*

* * **

***

** ***

***

*

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§ Improved partial level scheme (2018)§~2.4 MeV between "#$ and highest level

D.J. Hartley et al., Phys. Rev. Lett., 120:182502 (2018).

Recent Work on 160Eu → 160Gd

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Experimental Setup

Moving Tape Collector and Zero Degree Scintillator Gamma-Ray Infrastructure For

Fundamental Investigations of Nuclei

§ Zero Degree Scintillator for beta detection

§ 15 large-volume GRIFFIN High Purity Germanium detectors

Cyclotron and production targets

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Coincidence Analysis§ Events within given time are in coincidence → same decay§ Coincident transitions in cascade§ Parallel transitions are not in coincidence

Energy [keV]820 840 860 880 900 920 940 960 980 1000

Ener

gy [k

eV]

40

60

80

100

120

140

160

180

200

220

1

10

210

310

410

matrix ZDS coincidenceγ-γ

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Energy [keV]700 750 800 850 900 950 1000

0

5000

10000

15000

20000

25000

Gate: 173 keV

Coincidence Analysis

822 keV

No 995 keV

§ Events within given time are in coincidence → same decay§ Coincident transitions in cascade§ Parallel transitions are not in coincidence

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Energy [keV]700 750 800 850 900 950 10000

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

Gate: 75 keV

Coincidence Analysis

822 keV

995 keV

§ Events within given time are in coincidence → same decay§ Coincident transitions in cascade§ Parallel transitions are not in coincidence

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Structure of 160Gd

§ Confirmation of:§ 5/7 excited states [1]§ 7/11 excited states [2]§ 9/9 excited states [3]

§ Previously unpublished:§ 21 excited states§ 56 transitions

*Preliminary*

[3] D.J. Hartley et al., Phys. Rev. Lett., 120:182502 (2018).

[1] J.M. D’Auria et al., Can. J. Phys. 51, 686 (1973).[2] N.A. Morcos et al., J. Inorg. Nucl. Chem. 35, 3659 (1973).

64160 Gd96

0+ 0

2+ 75.4

4+ 248.6

6+ 514.8

8+ 868.02+ 988.93+ 1057.94+ 1070.9

(5)+ 1173.5

1- 1224.75+ 1261.5

(6)+ 1296.01351.61377.3

6+ 1392.31437.4

(5)+ 1438.04+ 1483.7(7)+ 1548.6(5)+ 1582.0

1608.7

(2)- 1932.4

(5)- 1998.9

2328.2(5)+ 2345.0

(1) 2363.1

(1) 2464.9

(5)- 2489.62511.5

(5)- 2559.6

3090.3

3115.8

75.4

173.

226

6.2

353.

291

3.6

988.

9808.

798

2.5

81.5

555.

782

2.1

995.

5102.

811

5.9

658.

392

4.9

1149

.512

24.7

204.

274

6.4

1012

.922

4.9

780.

810

47.4

1276

.413

51.6

319.

413

01.8

878.

411

43.7

1188

.713

61.5

264.

418

7.7

309.

941

2.5

968.

512

35.0

1408

.368

0.4

1033

.898

.928

6.0

408.

538

4.0

874.

794

3.4

1683

.718

57.0

417.

045

0.5

515.

660

5.7

737.

882

5.8

928.

314

84.1

1270

.376

3.0

1171

.913

05.2

2287

.7855.

910

28.1

1087

.911

13.5

2389

.724

64.9

490.

710

06.8

1052

.711

94.4

1316

.912

86.8

560.

710

76.9

1122

.712

64.5

1387

.028

41.7

2044

.9

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Multiple Decaying States

D.J. Hartley et al., Phys. Rev. Lett., 120:182502 (2018).

State This work D.J. Hartley et al.0- isomeric state t1/2 = 18(10) s t1/2 = 30.8(5) s

5- ground state t1/2 = 45(2) s t1/2 = 42.6(5) s

Time [s]0 10 20 30 40 50 60 70 80 90

Cou

nts

0

10

20

30

40

50

Isomeric-state Decay

Time [s]0 20 40 60 80 100

Cou

nts

50

100

150

200

250

Ground-state Decay

t1/2 = 45(2) s

t1/2 = 18(10) s

*Preliminary*

*Preliminary*

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Summary

§New information on 160Eu→160Gd !-decay

§Confirmation of most known levels and transitions

§21 new excited states and 56 new transitions

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Thank youMerci

D. Yates1,2, R. Krücken1,2, I. Dillmann1,3,F.A. Ali4, C. Andreiou5, W. Ashfield6, Z. Beadle6, N. Bernier1,2, S. Bhattacharjee1, H. Bidaman4, V. Bildstein4, D. Bishop1, M. Bowry1, C. Burbage4, R. Caballero-Folche1, D.Z. Chaney7, D. Cross5, A. Diaz Varela4, M. Dunlop4, R. Dunlop4, L. Evitts1,2, F.H. Garcia5, A.B. Garnsworthy1, P.E. Garrett4, S. Georges1,

F. Ghazi Moradi4, S. Gillespie1, J. Henderson1, S. Jigmeddorj4, C. Jones1,8, K. Leach9,

B.K. Luna7, A. MacLean4, C. Natzke9, B. Olaizola1, H. Patel1,10, C. Petrache11, A. Radich4, M.M. Rajabali7, P. Regan8, Y. Saito1,2, J. Smallcombe1, J.K. Smith6, M.

Spencer1,8, M. Spieker12, C.E. Svensson4, K. Whitmore5, T. Zidar4

1 TRIUMF2 UBC3 UVic4 Guelph

9 Colorado Mines10 Waterloo11 Orsay12 NSCL

5 SFU6 Reed College7 Tennessee Tech8 Surrey