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2019-02-16
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Decay Spectroscopy of 160Eu Using the GRIFFIN Spectrometer
Daniel YatesUniversity of British Columbia/TRIUMF
2
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
3
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
4
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
5
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
14
Dis
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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
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