Download - Ge 74 Gamma-ray strength functions in
Text optional: Institutsname Prof. Dr. Hans Mustermann www.fzd.de Mitglied der Leibniz-GemeinschaftRonald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Gamma-ray strength functions in 74Ge
Ronald Schwengner
Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf
01328 Dresden, Germany
• Dipole strength up to the neutron-separation energy:
- Photon-scattering experiments at γELBE
• M1 and E2 strength at low energy:
- Shell-model calculations
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Study of germanium isotopes
Extraction of neutron-capture cross sections for astrophysically relevant neutronenergies.
Test of strength functions deduced from different reactions.
Combination of experiments using neutron capture and alternative reactiontechniques in an international collaboration:
– Neutron capture at IKI Budapest.
– Discrete γ-ray spectroscopy at STARS-LIBERACE (LBNL)and AFRODITE (iThemba).
– Statistical γ-ray measurements at CACTUS (Oslo)and γELBE (HZDR).
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
The bremsstrahlung facility at the electron accelerator ELBE
Accelerator parameters:
• Maximum electron energy:
≈ 18 MeV
• Maximum average current:
≈ 0.8 mA
• Micro-pulse rate:
13 MHz
• Micro-pulse length:
≈ 5 ps
R.S. et al., NIM A 555, 211 (2005)
1 m
Be window
dipole
dipole
dipole
radiator
steerer
quadrupoles
quadrupole
electron-beam dump
quartz windowbeam
hardener
collimator
polarisationmonitor
target
PbPE
door
Pb
photon-beamdump
Pb
HPGe detector
experimentalcave
acceleratorhall
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Detector setup at γELBE
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Measurement at γELBE
1 2 3 4 5 6 7 8 9 10 11Eγ (MeV)
105
106
107
108
109
Cou
nts
per
10 k
eV experimental spectrum
74Ge(γ,γ’) Ee
kin = 12.1 MeV θ = 127
o
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Measurement at γELBE
1 2 3 4 5 6 7 8 9 10 11Eγ (MeV)
105
106
107
108
109
Cou
nts
per
10 k
eV experimental spectrum
74Ge(γ,γ’) Ee
kin = 12.1 MeV θ = 127
o
response−corrected
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Measurement at γELBE
1 2 3 4 5 6 7 8 9 10 11Eγ (MeV)
105
106
107
108
109
Cou
nts
per
10 k
eV experimental spectrum
atomic background
74Ge(γ,γ’) Ee
kin = 12.1 MeV θ = 127
o
response−corrected
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Photon scattering - feeding and branching
0Γ0
Γ1
E ,x Γ
branchingΓf
Ee
Measured intensity of a γ transition:
Iγ(Eγ, Θ) = Is(Ex) Φγ(Ex) ǫ(Eγ) Nat W (Θ) ∆Ω
Integrated scattering cross section:
Is =
∫
σγγ dE =2Jx + 1
2J0 + 1
(
πhc
Ex
)2Γ0
ΓΓ0
Absorption cross section:
σγ = σγγ
(
Γ0
Γ
)
−1
E1 strength:
B(E1) ∼ Γ0/E 3
γ
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Photon scattering - feeding and branching
0Γ0
Γ1
Ee
E ,x Γ
branchingΓf
feeding
Measured intensity of a γ transition:
Iγ(Eγ, Θ) > Is(Ex) Φγ(Ex) ǫ(Eγ) Nat W (Θ) ∆Ω
Integrated scattering cross section:
Is =
∫
σγγ dE =2Jx + 1
2J0 + 1
(
πhc
Ex
)2Γ0
ΓΓ0
Absorption cross section:
σγ = σγγ
(
Γ0
Γ
)
−1
E1 strength:
B(E1) ∼ Γ0/E 3
γ
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Simulations of γ-ray cascades
Code γDEX:
G. Schramm et al., PRC 85, 014311 (2012)
R. Massarczyk et al., PRC 86, 014319 (2012);
PRC 87, 044306 (2013)
0
Γ0 Γ1 2Γ
Γ JE π
⇒ Level scheme of J = |J0±1, ..., 5| states in 10 keV
energy bins constructed by using:
Constant-Temperature Model with level-density
parameters from T. v. Egidy, D.Bucurescu, PRC
80, 054310 (2009).
Parity distribution of level densities according to
S. I. Al-Quraishi et al., PRC 67, 015803 (2003).
Wigner level-spacing distributions.
⇒ Partial decay widths calculated by using:
Photon strength functions approximated by
Lorentz curves (www-nds.iaea.org/RIPL-2).
Porter-Thomas distributions of decay widths.
⇒ Subtraction of feeding intensities and correction
of intensities of g.s. transitions with calculated
branching ratios Γ0/Γ .
⇒ Determination of the absorption cross section.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Average branching ratios of ground-state transitions in 74Ge
1 2 3 4 5 6 7 8 9 10 11Ex (MeV)
0
20
40
60
80
100
b 0∆ (%
)
74Ge
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Iterative determination of the absorption cross section
3 4 5 6 7Ex (MeV)
0
1
2
3
σ γ (m
b)
74Ge(γ,γ’)
7.5 MeV
uncorr.
5 6 7 8 9 10 11Ex (MeV)
0
5
10
σ γ (m
b)
74Ge(γ,γ’)
12.5 MeV
Sn
uncorr.
Cross section including strength of resolved peaks and of quasi-continuum.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Iterative determination of the absorption cross section
3 4 5 6 7Ex (MeV)
0
1
2
3
σ γ (m
b)
74Ge(γ,γ’) 1. iteration
7.5 MeV
uncorr.
5 6 7 8 9 10 11Ex (MeV)
0
5
10
σ γ (m
b)
74Ge(γ,γ’)
1. iteration
12.5 MeV
Sn
uncorr.
Cross section including strength of resolved peaks and of quasi-continuum.
Result of the correction for feeding intensities and branching ratios used as input for the next calculation.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Iterative determination of the absorption cross section
3 4 5 6 7Ex (MeV)
0
1
2
3
σ γ (m
b)
74Ge(γ,γ’) 1. iteration
7.5 MeV
4. iteration
uncorr.
5 6 7 8 9 10 11Ex (MeV)
0
5
10
σ γ (m
b)
74Ge(γ,γ’)
1. iteration
12.5 MeV
Sn
5. iteration
uncorr.
Cross section including strength of resolved peaks and of quasi-continuum.
Result of the correction for feeding intensities and branching ratios → used as input for the next calculation.
Convergence criteria fulfilled → data taken as final results.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Absorption cross section of 74Ge
3 4 5 6 7 8 9 10 11Ex (MeV)
0
2
4
6
8
10
σ γ (m
b)
74Ge(γ,γ’)
7.5 MeV
12.5 MeV
Sn
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Absorption cross section of 74Ge
0 5 10 15 20 25Ex (MeV)
100
101
102
σ γ (m
b)
74Ge
(γ,γ’)7.5 MeV
(γ,γ’)12.5 MeV
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Absorption cross section of 74Ge
0 5 10 15 20 25Ex (MeV)
100
101
102
σ γ (m
b)
74Ge
(γ,γ’)7.5 MeV
(γ,γ’)12.5 MeV
(γ,x)
(γ,x) data:
P. Carlos et al.,
NPA 258, 365 (1976)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Absorption cross section of 74Ge
0 5 10 15 20 25Ex (MeV)
100
101
102
σ γ (m
b)
74Ge
(γ,γ’)7.5 MeV
(γ,γ’)12.5 MeV
TLO(γ,x)
(γ,x) data:
P. Carlos et al.,
NPA 258, 365 (1976)
TLO (β2 = 0.28, γ = 27):
A. Junghans et al.,
PLB 670, 200 (2008)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Electromagnetic strength functions
Electromagnetic strength functions (photon strength functions) describe averageelectromagnetic transitions strengths - in particular in the quasi-continuum of nuclearstates at high excitation energy:
ffiL(Eγ) = ΓfiL ρ(Ei , Ji) / E2L+1
γ Eγ = Ei − Ef Ji = 0, ..., Jmax
Photoabsorption:
fL = σγ / [(2Ji+1)/(2J0+1) (πhc)2E
2L−1
γ ] Eγ = Ei Ji = 1, (2)
Brink-Axel hypothesis:The strength function does not depend on the excitation energy.The strength function for excitation is identical with the one for deexcitation.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
100
101
102
f 1 (1
0−9 M
eV−
3 )
74Ge
(γ,γ’)7 MeV (γ,γ’)12 MeV
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
100
101
102
f 1 (1
0−9 M
eV−
3 )
74Ge (
3He,
3He’)
(γ,γ’)7 MeV (γ,γ’)12 MeV
(3He,3He’) data:
T. Renstrøm et al.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
100
101
102
f 1 (1
0−9 M
eV−
3 )
74Ge (
3He,
3He’)
(γ,γ’)7 MeV (γ,γ’)12 MeV
TLO
(3He,3He’) data:
T. Renstrøm et al.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
100
101
102
f 1 (1
0−9 M
eV−
3 )
74Ge (
3He,
3He’)
(γ,γ’)7 MeV (γ,γ’)12 MeV
TLO GLO
(3He,3He’) data:
T. Renstrøm et al.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Shell-model calculations of M1 strength functions
0 2 4 6 8 10 12 14 16Eγ (MeV)
10−2
10−1
100
101
102
103
f 1 (1
0−9 M
eV−
3 )
94Mo
(3He,
3He’) data
shell modelM1
E1 + M1 (γ,n) data
E1
)-3
(M
eV
M1
f
-910
-810
-710
Fe, Voinov et al. (2004) 56
)γαHe,3
(
Fe, Larsen et al. (2013) 56
)γ (p,p'
SM calc
Fe56
(a)
(MeV)γE0 1 2 3 4 5 6 7
)-3
(M
eV
M1
f-9
10
-810
-710
Fe57
(b)Fe, Voinov et al. (2004)
57)γHe'
3He,
3 (
Fe, Larsen et al. (2013/2014) 57
)γ (p,p'
SM calc
RITSSCHIL NuShellX
R.S., S. Frauendorf, A.C. Larsen
PRL 111, 232504 (2013)
B.A. Brown, A.C. Larsen
PRL 113, 252502 (2014)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Generation of large M1 strengths
J + 1
J
J π
ν
J π
J ν
J
M1
⇒ Configurations including protons and neutrons in specific high-j orbits with large magneticmoments.
⇒ Coherent superposition of proton and neutron contributions for specific combinations ofgπ and g ν factors and relative phases (“mixed symmetry”).
⇒ Large M1 strengths appear between states with equal configurations by a recoupling ofthe proton and neutron spins (analog to the “shears mechanism”).
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
10−1
100
101
f 1 (1
0−9 M
eV−
3 ) 74Ge(
3He,
3He’)
GLO(3He,3He’) data:
T. Renstrøm et al.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
10−1
100
101
f 1 (1
0−9 M
eV−
3 )
74Ge
74Ge(
3He,
3He’)
M1 calc.
GLO(3He,3He’) data:
T. Renstrøm et al.
RITSSCHIL
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Dipole strength functions in 74Ge
0 2 4 6 8 10 12Eγ (MeV)
10−1
100
101
f 1 (1
0−9 M
eV−
3 )
74Ge
74Ge(
3He,
3He’)
M1 calc.
80Ge GLO
(3He,3He’) data:
T. Renstrøm et al.
RITSSCHIL
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Predicted Appearance of magnetic rotation
0 20 40 60 80 100 120 140 160020406080100120140
Neutron Number N
ProtonNumberZ j"2j0.250.1528 50 82 12628 50 8264 642020
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . .. . . . . ...............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
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....................................................................................................................................................S. Frauendorf, Rev. Mod. Phys. 73, 463 (2001).
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Generation of large M1 strengths
B(M1) ∼ µ2
⊥
Analogous “shears mechanism”
in magnetic rotation
S. Frauendorf, Rev. Mod. Phys. 73, 463 (2001).
Examples near A = 80: 82Rb, 84Rb
H. Schnare et al., PRL 82, 4408 (1999).
R.S. et al., PRC 66, 024310 (2002).
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Shell-model calculations for 74Ge and 80Ge
Main configurations that generate large M1 transition strengths(active orbits with jπ 6= 0 and jν 6= 0):
74Ge π = +: π(0f45/2
) ν(0g2
9/2) π = –: π(0f4
5/2) ν(1p−1
1/20g3
9/2)
π(0f35/2
1p1
3/2) ν(0g2
9/2) π(0f3
5/21p1
3/2) ν(1p−1
1/20g3
9/2)
π(0f25/2
1p2
3/2) ν(0g2
9/2) π(0f2
5/21p2
3/2) ν(1p−1
1/20g3
9/2)
80Ge π = +: π(0f45/2
) ν(0g8
9/2) π = –: π(0f3
5/20g1
9/2) ν(0g8
9/2)
π(0f35/2
1p1
3/2) ν(0g8
9/2) π(0f2
5/21p1
3/20g1
9/2) ν(0g8
9/2)
π(0f35/2
1p1
3/2) ν(0g7
9/21d1
5/2) π(0f3
5/20g1
9/2) ν(0g7
9/21d1
5/2)
⇒ Configurations including a broken ν0g9/2 pair in addition to π(fp) excitations.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
E2 strength function in 94Mo
0 2 4 6 8 10 12 14 16Eγ (MeV)
100
101
102
f 2 (1
0−12
MeV
−5 )
94Mo
RIPL
E2 strength function in RIPL
Lorentz curve with:
Emax = 63 A−1/3 MeV
Γ = 6.11 – 0.021A MeV
σγ,max = 0.00014 Z2EmaxA
−1/3Γ−1 mb
R.S., PRC 90, 064321 (2014)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
E2 strength function in 94Mo
0 2 4 6 8 10 12 14 16Eγ (MeV)
100
101
102
f 2 (1
0−12
MeV
−5 )
94Mo
RIPL
shell model
E2 strength function
f2 = 0.80632 B(E2) ρ(Ex ,J)
ρ(Ex , J) - level density
of the shell-model states,
includes π = ± 1,
J = 0 to 10,
40 states for each Jπ.
RITSSCHIL
R.S., PRC 90, 064321 (2014)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
E2 strength function in 94Mo
0 1 2 3 4 5 6Eγ (MeV)
0
5
10
B(E
2) (
e2 fm4 )
94Mo, π = +
Jf = Ji + 2, 6602 transitions
Jf = Ji − 2, 7798 transitions
Ji = 2k to 10k, k = 1 to 40
Jf = Ji, Ji 1, 22196 transitions
all
+−
RITSSCHIL
R.S., PRC 90, 064321 (2014)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
E2 strength function in 74Ge
0 1 2 3 4 5 6Eγ (MeV)
0
1
2
3
4
5
B(E
2) (
e2 fm4 )
74Ge, π = +
Jf = Ji + 0,1,2; 36581 transitions
Jf = Ji − 2; 9002 transitions
Ji = 0k to 10k, k = 1 to 40
−
RITSSCHIL
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
E2 strength function in 64Fe
0 1 2 3 4 5 6Eγ (MeV)
0
5
10
15
20
25
B(E
2) (
e2 fm4 )
64Fe, π = + ; ca48mh1
Jf = Ji + 0,1,2; 36593 transitions
Jf = Ji − 2; 9082 transitions
Ji = 0k to 10k, k = 1 to 40
−
B(E2, 2+
1 → 0+
1 )exp = 470+210−110 e2fm4
J. Ljungvall et al., PRC 81, 061301 (2010)
B(E2, 2+
1 → 0+
1 )calc = 406 e2fm4
NuShellX: B.A. Brown, W.D.M. Rae, NDS 120, 115 (2010)
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Summary
Photon-scattering experiments on 74Ge with bremsstrahlung at γELBE using 7.5 and12.1 MeV electrons.
Determination of the dipole strength function at high excitation energy and high leveldensity. Inclusion of strength in the quasicontinuum and correction of the observedstrength for branching and feeding by using statistical methods.
No considerable enhancement of E1 strength in the pygmy region.
Good agreement between the strength functions deduced from the present (γ, γ′)
experiments and from (3He,3He’) experiments.
Low-energy enhancement observed in the (3He,3He’) experiment qualitatively de-scribed by M1 strength functions calculated within the shell model.Large M1 strengths result from a recoupling of the spins of specific high-j proton andneutron orbits.
E2 strength functions at low energy calculated within the shell model show simi-lar characteristics in various mass regions and are at variance with approximationsrecommended in RIPL.
Ronald Schwengner | Institut für Strahlenphysik | http://www.hzdr.de
Collaborators
Motivation: L.A. Bernstein (LLNL, Univ. Berkeley)
Data analysis: R. Massarczyk (HZDR, LANL)
Data acquisition: A. Wagner
Technical assistence: A. Hartmann
Experimenters: M. Anders, D. Bemmerer, R. Beyer, Z. Elekes, R. Hannaske,A.R. Junghans, T. Kogler, M. Roder, K. Schmidt, L. Wagner