Concluding Remarks
Andreas ZilgesInstitut für KernphysikUniversität zu Kölnwww.zilges.de
2nd Workshop on Level Density and Gamma Strength Oslo, May 11 - 15, 2009
(A very subjective, biased, and politically incorrectpoint of view of a non-expert.)
0 50 100 150 200 250
0.1
1
10
RIPL-2 Mughabghab RIPL-3
Mass number
S0 1
0 4
0 5 10 15 20 2510-6
10-5
10-4
10-3
10-2
10-1
100
101
102
103
experiment Fermi-gas Constant Temperature
Cros
s se
ctio
n, m
b/M
eV
Proton energy, MeV
6Li+55Mn
Sn
p,n
n pn
(γ,γ)
pn
2000 4000 6000 8000 10000 12000 14000 160001
10
100
1k
10k
100k
1M
Coun
ts/C
hann
el
Channel number
2000 4000 6000 8000 10000
1
10
100
1k
10k
100k
1M
E (keV)
5 6 7 8 9 10 11 12 13 14 15 16 17 18100
101
102 Nilsson WS
Talys
88Sr
(γ,γ)
(γ,n)
σ γ /
mb
Ex / MeV
continuum
Rauscher0
25
50 SD-gated 1. Ridge
N path
e)0
25
50SD-gated 1. Ridge
f)
020406080 2. Ridge
No decay-out
N path
c)0
40
80
120No decay-out
2. Ridge
d)
20 30 40 50 60 700
50
100
196Pb151Tb
No decay-out
1. Ridge
N path
Spin []
a)10 20 30 40 50 0
50
100
150No decay-out
1. Ridge
Spin []
b)
8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.00
10
20
30
40
50
60
(Ep=
4 M
eV)
(Ep=
4.8
MeV
)
(Ep=
5.6
MeV
)
(Ep=
6.4
MeV
)
Cou
nts /
mC
(10
4 )
Eγ (keV)
104Pd(p,γ)105Ag
0 1 2 3 4 5 6 7 810-1
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
ρBCS(U) x ρCOLL(U) ρBCS(U)
Dcalc0 = 0.50 +/- 0.15
LEVE
L DE
NSIT
Y [M
eV-1]
Excitation Energy U [MeV]
234U
0 50 100 150 200 250 3000
20
40
60
80
100
120
140
Sum
of r
educ
ed n
eutro
n wi
dths
Neutron energy, keV
SumgGn0 S=0.46+/-0.15 S=0.37+/-0.12
Ti-50p-resonances
What do we want to achieve ?
• Derive a reliable and comprehensive dataset on level densities and gamma ray strengthfunctions;
• understand impact of spin, parity, deformation,damping, collective enhancement, low lyingstates, K-quantum number, and chaoticity;
• establish a well founded, global, and robusttheoretical description;
• apply the knowledge in neighbouring fields.
Experimental Approaches
The Oslo Method Alexander BürgerHilde T. NyhusHeide K. Toft
The Oslo Method
The Oslo Method
The Oslo Method
Experimental Approaches
The Oslo Method Alexander BürgerHilde T. NyhusHeide K. Toft
The Ohio Method Alexander Voinov(p,2γ) and (d,n), exotic nuclei Steve Grimes
The Ohio MethodTesting the technique with 27Al(d,n)28Si
0 2 4 6 8 10 12 14 16
10-2
10-1
100
101
102
Experiment, from 27Al(d,n)28Si reaction From counting of discrete levels
Leve
l den
sity,
1/M
eV
Excitation energy, MeV
Level density of 28Si
Excitation energy, MeV
Experimental Approaches
The Oslo Method Alexander BürgerHilde T. NyhusHeide K. Toft
The Ohio Method Alexander Voinov(p,2γ) and (d,n), exotic nuclei Steve Grimes
Neutron capture Gary Mitchell@DANCE and n_TOF Stefano Marrone
Two step cascade method Milan Krticka(n capture + dicebox)
Neutron capture data
G. Mitchell
Experimental ApproachesPhoton induced reactions Hiroaki Utsunomiya(monoenergetic photons) Anton Tonchev
Photon induced reactions Ronald Schwengner(bremsstrahlung photons)
Alpha scattering Janis Endres(α,α‘γ)
PDR in Coulex excitation Oliver Wieland(virtual photons, inverse kinematics)
Pygmy Dipole Resonance
91Zr(γ,n)90Zr
92Zr(γ,n)91Zr
94Zr(γ,n)93Zr
M1
M1
M1
E1: HFB+QRPA
E1
E1
H. UtsunomiyaJ. Endres
Pygmy Dipole Resonance
Experimental Approaches
Neutron spectra Boris Zhuravlev(p,n)@IPPE
Surrogate reactions Jutta EscherBethany Lyles Goldblum
Lifetimes Mathis Wiedeking(near particle separation)
Surrogate reactions – cross section
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0 100 200 300 400 500 600
Equivalent Neutron Energy (keV)
— ENDF/B-VII
(3He,3He’) Surrogate Data
(3He,α) Surrogate Data
161Dy(n,γ)
Theoretical Approaches
The Brink hypothesis David Brink
IBA folded with intrinsic Roberto Capotelevel densities
Monte Carlo Yoram AlhassidHitoshi Nakada
Shell Model Monte Carlo
Theoretical Approaches
The Brink hypothesis David Brink
IBA folded with intrinsic Roberto Capotelevel densities
Monte Carlo Yoram AlhassidHitoshi Nakada
Microcanonical model Sven Aberg
Combinatorial level density –comparison to Oslo data
S. Aberg
Theoretical Approaches
The Brink hypothesis David Brink
IBA folded with intrinsic Roberto Capotelevel densities
Monte Carlo Yoram AlhassidHitoshi Nakada
Microcanonical model Sven Aberg
Instantaneous-shape sampling Stefan Frauendorf
Instantaneous-Shape Sampling
S. Frauendorf
Theoretical Approaches
Microscopic combinatorial model Stephane Hilaire(spin and parity dependence)
Quasiparticle-phonon model Nicola Lo Iudice(influence of phonons on nuclear response)
Modified Lorentzian approach Vladimir A. Plujko(comparison of different models)
Deformed systems Katarzyna Mazurek(Tetrahedal/octrahedal shapes)
Influence of phonons
N. Lo Iudice
Hot nuclei and quantum chaos
Warm superdeformed nuclei Silvia Leoni
Superthings Teng Lek Khoo(superdeformed and superheavy)
Superdeformed bands
Teng Lek Khoo
Hot nuclei and quantum chaos
Warm superdeformed nuclei Silvia Leoni
Nuclear Chaoticity Jose M. Gomez
Superthings Teng Lek Khoo(superdeformed and superheavy)
Thermodynamics and Vladimir Zelevinskyquantum chaos
Pair correlator
V. Zelevinsky
Nuclear Data
RIPL-3 Anatoly Ignatyuk(neutron resonances density)
Nuclear Structure and Richard B. FirestoneStatistical Decay Properties
Level densities from nuclear Frank Gunsingdata libraries
Parity dependence
R.B. Firestone
Applications
Nucleosynthesis Stephane GorielySotirios HarissopulosLee Bernstein
Reactor physics Jonathan Wilson(nuclear data importance for
generation IV reactors)
Nucleosynthesis
0 50 100 150 200 250
0.1
1
10
RIPL-2 Mughabghab RIPL-3
Mass number
S0 1
0 4
0 5 10 15 20 2510-6
10-5
10-4
10-3
10-2
10-1
100
101
102
103
experiment Fermi-gas Constant Temperature
Cros
s se
ctio
n, m
b/M
eV
Proton energy, MeV
6Li+55Mn
Sn
p,n
n pn
(γ,γ)
pn
2000 4000 6000 8000 10000 12000 14000 160001
10
100
1k
10k
100k
1M
Coun
ts/C
hann
el
Channel number
2000 4000 6000 8000 10000
1
10
100
1k
10k
100k
1M
E (keV)
5 6 7 8 9 10 11 12 13 14 15 16 17 18100
101
102 Nilsson WS
Talys
88Sr
(γ,γ)
(γ,n)
σ γ /
mb
Ex / MeV
continuum
Rauscher0
25
50 SD-gated 1. Ridge
N path
e)0
25
50SD-gated 1. Ridge
f)
020406080 2. Ridge
No decay-out
N path
c)0
40
80
120No decay-out
2. Ridge
d)
20 30 40 50 60 700
50
100
196Pb151Tb
No decay-out
1. Ridge
N path
Spin []
a)10 20 30 40 50 0
50
100
150No decay-out
1. Ridge
Spin []
b)
8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.00
10
20
30
40
50
60
(Ep=
4 M
eV)
(Ep=
4.8
MeV
)
(Ep=
5.6
MeV
)
(Ep=
6.4
MeV
)
Cou
nts /
mC
(10
4 )
Eγ (keV)
104Pd(p,γ)105Ag
0 1 2 3 4 5 6 7 810-1
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
ρBCS(U) x ρCOLL(U) ρBCS(U)
Dcalc0 = 0.50 +/- 0.15
LEVE
L DE
NSIT
Y [M
eV-1]
Excitation Energy U [MeV]
234U
0 50 100 150 200 250 3000
20
40
60
80
100
120
140
Sum
of r
educ
ed n
eutro
n wi
dths
Neutron energy, keV
SumgGn0 S=0.46+/-0.15 S=0.37+/-0.12
Ti-50p-resonances
ARSF = Anatoly‘s Remarks Strength Function
UNIFIED THEORY OF NUCLEARMODELS AND FORCES
UNIFIED THEORY OF NUCLEARMODELS AND FORCES
Sunniva Siem, Alexander Bürger, Magne GuttormsenAndreas Görgen, Trine W. Hagen, Ann-Cecilie Larsen
Hilde Therese Nyhus, John Rekstad, Therese RenstromSunniva J. Rose, Naeem Syed, Heidi Toft, Kristine Wikan
THANK YOU !!!
