High-Spin State Studies with Deep-Inelastic Heavy Ion Reactions
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Transcript of High-Spin State Studies with Deep-Inelastic Heavy Ion Reactions
High-Spin State Studies with
Deep-Inelastic Heavy Ion Reactions
Rafał Broda
Niewodniczanski Institute of Nuclear Physics PANKraków, Poland
GaspGasp
Thick Target Eksperiments Thick Target Eksperiments
R. Broda et al., JPG 32, 151 (2006)
All reaction products stopped in the target Discrete gamma lines observed except for those arising from short-lived states
High statistics-coincidences are collected including high folds and time parameters correlated with beam pulsing
Selectivity based solely on complex gamma-coincidence analysis
Identification of yrast state structures - in previously inaccessible nuclei, predominantly in the neutron-rich region
GAMMASPHERE
B.Fornal, W.Królas, T.Pawłat, J.Wrzesiński, R.B.
Purdue University, W.Lafayette, IN, USAArgonne National Laboratory, Argonne, Ill, USAHahn-Meitner Institut, Berlin, GermanyINFN LNL Legnaro/Padova University, WłochyGesellschaft fuer Schwere Ionen, Darmstadt, GermanyJYFL-University of Jyvaskyla, FinlandLBL Berkeley, Cf, USA
92Mo + 60Ni
56Fe
96Ru
(Argonne-Notre Dame Array)
48Ca (330 MeV) + 238U (thick target)GAMMASPHERE at Argonne
48Ca
66Ni
0.80
0.90
1.00
1.10
1.20
0 10 20 30 40 50 60 70 80 90
rela
tive
inte
nsity
angle [deg]
66Ni 1760 keV 1425 keV
a2 = 0.09(2), a4 = 0.03(2)
0.80
0.90
1.00
1.10
1.20
0 10 20 30 40 50 60 70 80 90
rela
tive
inte
nsity
angle [deg]
66Ni 1760 keV 356 keV
a2 = -0.09(1), a4 = 0.02(1)
f7/2 p3/2 p1/2 f5/2
PRISMA spectrometerPRISMA spectrometer A magnetic heavy ion
spectrometer designed to fully identify (A, Z) fragments deflected at large angles
CLARA: an array of 24 Clover detectors
238U + 330 MeV 48Ca
Complementary sets of data: PRISMA – (A,Z) identification, fast transitionsand GAMMASPHERE – -coincidence data
_
p1/2
f5/2
0
2
4
(4 )
(5 )
(7 )
(5 )+
-
(5 )-
-
-
+
-
+
+
1 0 2 7
2 9 7 13 4 8 8
0
1 0 2 6 .8
3 9 9 7 .4
4 8 3 0 .8
4 5 1 5 .3
5 1 4 7 .65 5 1 7 .3
6 8 7 0 .1
1 76 01 35 3
1 0 88
8 33
5 18
4 07 4 325 11 0 .15 0 8 5 .0(4 )-
6 32
1 00 2
5 95
111 3
1 51 9
Ca5020 30
2+
N/Z=1.54
N/Z=1.29
232Th + 136Xe Berkeley experimentwith ~ 80 Gammasphere detectorsJ.F.C.Cocks et al. Phys.Rev.Lett.78,2920 (1997)J.F.C.Cocks et al. Nucl.Phys.A645, 61 (1999)
208208Pb early high spin states studyPb early high spin states study
(e,e’) - J.P. Connelly at al., Phys. Rev. C 45, 2711 (1992)
Deep Inelastic Reactions64Ni + 208Pb - M. Schramm at al., Z. Phys. A 344, 363, (1993)
208Pb (1360 MeV) + 238UGammasphere at Argonne
N/Z=1.54
N/Z=1.59
206Hg
4-
8+
14-
9+
15-
16-
20+
19+
19+
81 123
2-
7+
9+
8+
4-
14-
15-
12-
18+
16-
19+19+
20+
22-
SM Eexp –Ecalc [keV]
-49+99
+158
+114+114
+182
+207
+40
+17
+70+58
+58+31
+36
π s1/2 ν f5/2-1
π h11/2-1 ν i13/2
-1
π s1/2 ν i13/2-1
π h11/2-1 ν p1/2
-1i13/2-2
π h11/2-1 ν i13/2
-3
Gamma transitions preceding in time highest isomers
I ~ 30
25+
25+
E3 !
[π h11/2- 1 ν i 13/2
-3] 22-
208Pb E3 2615 keV
π h11/2- 1 -150
ν i 13/2-3 -260
_____ 2205 keV
E3 - 2207 keV
1/2
3/2
7/2
9/2
11/2
15/2
17/219/2
25/2
29/2
35/2
39/2
204
720
506
54
570
340
157
739
328
1217
2256
942
375
807
2496
235(10) ns
2.6 s
0
204
924
14301484
2054
23942551
3291
3619
4836
7092
7332
78998034
8409
2 0 5 T l8 1 1 2 3
11/2 13/2 1/2[ h i p ] 1_1_1_
11/2 13/2[ h i ] 2_
1_
11/2 13/2 5/2[ h i f ] 1_1_1_
E3 !
[π h11/2- 1 ν i 13/2
-2] 35/2-
208Pb E3 2615 keV
π h11/2- 1 -150
ν i 13/2-2 -212
_____ 2253 keV
E3 - 2256 keV
124
Conclusions:
1. High spin states are abundantly populated in DIHI reactions
2. In light nuclei short lifetimes of excited states limit the study of high-spin states in thick target experiments
3. In heavy nuclei spin range of I=30 can be reached with the present gamma arrays detection sensitivity
4. Challenge - experiment is here more advanced than theory
5. Spectroscopic study of high-spin states in hard-to-reach nuclei is continued
beam: 48Ca @ 310 MeV provided by
TANDEM ALPI (1.5 pnA current)
accelerator complex;
target : 1 mg/cm2 stretched 208Pb (1
mg/cm2 Ta backing) ;
degrader : 4 mg/cm2 natMg;
PRISMA(49◦ grazing
angle)+CLARA;
Distances: 30 μm, 100 μm, 300 μm,
1240 μm, 2200 μm;
8-days beam-time.
J.J.Valiente-Dobon, D.Mengoni et al.
KrakKraków group and collaboratorsów group and collaborators
R. Broda, B. Fornal, W. Królas, T. Pawłat, J. Wrzesiński IFJ PAN Kraków
S. Lunardi, A. Gadea, N. Marginean, L. Corradi, A.M. Stefanini, F. Scarlassara, G. Montagnoli, M. Trotta, D. Napoli, E. Farnea Laboratori Nazionali di Legnaro and INFN Padova
R.V.F. Janssens, M.P. Carpenter, T. Lauritsen, D. Seweryniak, S. Zhu Argonne National Laboratory