V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 1 Progress Report on...

V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004

1

Progress Report on Theoretical Tools and Calculations of Cross Sections Relevant to

the EAF FileVlad Avrigeanu

EURATOM-MEC Fusion Association, “Horia Hulubei” National Institute for Physics & Nuclear Engineering, P.O Box MG-6, 76900 Bucharest, Romania

Since EAF-2003 (Prague, June 2002):

– Completion (2002/2003) of fast neutron activation calculations for:• all stable 58,60,61,62,64Ni isotopes (+ JRC/IRMM-Geel):

[Nucl. Phys. A730, 255 (2004)]• all stable 92,94,95,96,97,98,100Mo isotopes (+ JRC/IRMM, KRI-St.Petersburg): [http://tandem.nipne.ro/~vavrig/Publications/2003/papmo_1z.ps]

–Analysis (2003/2004) of fast neutron activation of:• all stable 180,182,183,184,186W isotopes (+ UKAEA, TUD-Dresden):

[Report EFFDOC-893, NEA/OECD, Paris, May 2004]


2

BASIC QUESTIONS

• NUCLEAR-SURFACE EFFECTS ?– in particle-hole level densities:

• PLD, CPCLibrary , Belfast, 1998]– Phys. Rev. C 58, 295 (1998)– Comp. Phys. Comm. 112, 191 (1998)

– in GDH model for pre-equilibrium emission:

• STAPRE-H95, OECD/NEA-DB, Paris, 1995]– J. Phys. G: Nucl. Phys. 20, 613 (1994)– Phys. Rev. C 65, 014604 (2001) – J. Nucl. Sci. Tech. Suppl. 2, 803 (2002)

• NUCLEAR MOMENT OF INERTIA ?– in nuclear level densities:

[e.g., S.F. Mughabghab, C. Dunford: Phys. Rev. Lett. 82, 4083 (1998)]– J. Nucl. Sci. Tech. Suppl. 2, 746 (2002)– Nucl. Phys. A730, 255 (2004)


3

Sensitivity of Activation Cross Sections of Tungsten to Nuclear Reaction Mechanisms

V. Avrigeanu1, R. Eichin2, R.A. Forrest3, H. Freiesleben2, M. Herman4, A.J. Koning5, and K. Seidel2

EFF-DOC-893/Rev.1 (June 2004)

1EURATOM-MEC Fusion Association, “Horia Hulubei” National Institute for Physics & Nuclear Engineering, P.O Box MG-6, 76900 Bucharest, Romania2EURATOM-FZK/TUD Fusion Association, Technische Universität Dresden,Dresden, Germany3EURATOM-UKAEA Fusion Association, Culham Science Center, United Kingdom4Brookhaven National Laboratory, P.O. Box 5000, Upton, NY 11973-50005Nuclear Research and Consultancy Group NRG, P.O. Box 25, 1755 ZG Petten, The Netherlands

– EMPIRE-II calculations: g=A/13 MeV-1 (default) A/14 MeV-1 – EMPIRE-II isomeric-state cross sections– (n,n’p+pn+d) reaction cross section discussion

Rev.1 (June 2004):


4

Outline [e.g.1, EFF-DOC-872, Nov. 2003]

• Nuclear cross sections calculations- Search for appropriate optical model potentials: n+182,183,184,186W

- p+ 181Ta- Compilation of the available experimental data (E<20 MeV)- Nuclear model calculations (E<20 MeV)- Comparison with all activation experimental data

• Processing of model calculations results- Cross sections of all individual channels with activation data-

• • [Benchmark experiment analysis updating

– calculated-to-experimental (C/E) activity: reduced deviation from unity ]

1P. Pereslavtsev and U. Fischer, Evaluation of n+184W cross-section data for EFF up to 150 MeV


5

Flowchart of model calculations

• EMPIRE-II v.2.18 [ECIS95/SCAT2, DEGAS, MSD-TUL/MSC-H, HF]

t, R, CC, abs - Tl(E) neutron deformed optical potential - p-, - spherical optical potentials - EMPIRE-specific level density, Nmax< 40

- DEGAS [g=A/13 MeV-1, K=100 MeV3]

• STAPRE-H v.2002 [SCAT2, GDH, HF] - p-, - spherical optical potentials - BSFG, E*<Bn: (a, D0-, Nmax-fit a(E*), E*>Bn: Junghans/Koning/Chadwick I/Ir: 0.5(g.s.)-0.75(Bn)-1(15 MeV) - GDH [ gFGM(), AK(p,h), fK(p,h,E,F1(l,Ei)) ]

• TALYS-0.58 [Koning and Duijvestijn]


6

Optical model potentials

• Neutrons (n+182,183,184,186W): SPRT analysis (SPR added in EMPIRE-II output)

– P.G. Young+ (1990) [as RIPL-2 in EMPIRE-II] (local)

– J.P. Delaroche, as in NEANDC-253”U”, OECD/NEA-DB, 1989 (local)

– P.G. Young, NEANDC-222”U”, OECD/NEA-DB, 1986 (global: II.B)

– P.G. Young+ (1990) - modified (local)

– RIPL-2/P.G. Young+ (1986) - modified (local)

• Protons (p+181Ta)– R.L. Walter and P.P. Guss, Rad. Effects 92, 1079 (1986) (global)

– N. Yamamuro, NDST-1988, Mito, Japan, p.489 (global)

– Walter-Guss (1986) - modified (local)

• Alphas– V. Avrigeanu, P.E. Hodgson, M. Avrigeanu, Phys.Rev.C 49,2137(1994) (global)


7

Optical model parameters used to describe the scattering of neutrons on W isotopes, and the corresponding absorption cross section for the

element W at the incident neutron energy E=14.1 MeV

Optical Potential(MeV)

R(fm)

A(fm)

abs (W)

(b)Modified Young (1986) Potential 2.627a

VR=49.8-0.3E-16b 1.26 0.61WV=-0.70+0.12, E>5.8 MeV 1.26 0.61WD=5.0+0.8E-8eV 12.2-0.1E-8eV

1.26 0.52

VSO=6.2 1.12 0.47Modified RIPL-2 Potential 2.402a

VR=49.23-0.25E-16eV =49.73-0.30E-16, E>10MeV

1.26+0.0033E, E<10 MeV1.359-0.0066E, 10<E<15 MeV1.26, E>15MeV

0.62+0.001E, E<10 MeV0.65-0.002E, 10<E<15MeV0.62, E>15MeV

WV=-1.4+0.2E, E>7 MeV 1.26 0.61WD=6.57+0.4E-8, E<4.5 MeV 8.82-0.1E-8, E>4.5 MeV

1.26 0.45

VSO=6.2 1.12 0.47a For comparison with the sum of

non=2.36±0.05 b at incident energy E=14.1 MeVcorresponding to inelastic scattering from above ~2 MeV of the excitation energy18, and a crosssection of ~0.04 b for statistical inelastic scattering on low-lying levels below ~2 MeV.

b =(N-Z)/A


8

Comparison of experimental and calculated neutron scattering parameters of 182,184,186W

PotentialS0*104

182WS1*104 R’(fm) S0*104

184WS1*104 R’(fm) S0*104

186WS1*104 R’(fm)

Exp.20 2.3(3) 7.3(3) 2.8(4) 0.58(7) 7.3(3) 2.1(4) 0.37(5) 7.3(3)RIPL-24 2.69 0.90 7.13 3.01 0.77 7.31 3.23 0.69 7.82Ref.15 2.55 1.14 7.37 2.75 0.99 7.51 2.80 0.87 7.86Ref.16 2.39 1.17 7.40 2.58 1.02 7.49 2.66 0.91 7.79Ref.16-mod. 2.23 1.07 7.38 2.41 0.94 7.46 2.52 0.85 7.74RIPL2-mod 2.24 1.11 7.46 2.39 0.99 7.52 2.57 0.90 7.74


9

Comparison of calculated and experimental neutron total cross sections for 182,183,184,186W isotopes with emphasis of the lower energy region

0.1 1 10

5

6

7

8

9Whalen+ (1966)Martin+ (1967)Foster+ (1971)Djumin+ (1977)Guenther+ (1982)Knopf+ (1987)Dietrich+ (2003)

RIPL2 (Young+, 1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL2-mod. (a)

n + 182

W

(b)

0.01 0.1 1 10

10

RIPL2 (Young+,1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL2-mod. (b)

n + 183

W Ohkubo+ (1978) #1 Ohkubo+ (1978) #2 Knopf+ (1982)

Abfalterer+ (2001): nat

W

0.1 1 10

5

6

7

8

9Whalen+ (1966)Martin+ (1967)Foster+ (1971)Djumin+ (1977)Guenther+ (1982)Knopf+ (1982) Dietrich+ (2003)

(c)

n + 184

W

RIPL2 (Young+, 1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL2-mod.

(b

)

En (MeV)0.1 1 10

5

6

7

8

9 Whalen+ (1966) Martin+ (1967) Foster+ (1971) Djumin+ (1977) Guenther+ (1982) Knopf+ (1982) Dietrich+ (2003)

(d)

n + 186

W

RIPL2 (Young+, 1990) Vonach-NagelN (1989) Young (1986)/Set II-B RIPL2-mod.

En (MeV)


10

Comparison of calculated and experimental neutron total cross sections for 182,183,184,186W isotopes

5

6

7

Whalen+ (1966) Martin+ (1967) Foster+ (1971) Djumin+ (1977) Guenther+ (1982) Knopf+ (1987) Dietrich+ (2003) RIPL2 (Young, 1990) Vonach-Nagel (1989) Young (1986) RIPL-2 mod.

(a)

n + 182

W

(b

)

5

6

7 Ohkubo+ (1978) #1 Ohkubo+ (1978) #2 Knopf+ (1982)


W RIPL2 (Young, 1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL-2 mod.

(b)

n + 183

W

0 5 10 15 20 25 30

5

6

7

Whalen+ (1966)Martin+ (1967)Foster+ (1971)Djumin+ (1977)Guenther+ (1982)Knopf+ (1982) Dietrich+ (2003) RIPL2 (Young+, 1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL-2 mod.

(c)

n + 184

W

(b

)

En (MeV)0 5 10 15 20 25 30

5

6

7

(d)

n + 186

W Whalen+ (1966) Martin+ (1967) Foster+ (1971) Djumin+ (1977) Guenther+ (1982) Knopf+ (1982) Dietrich+ (2003) RIPL2 (Young, 1990) Vonach-Nagel (1989) Young (1986)/Set II-B RIPL-2 mod.

En (MeV)


11

Comparison of neutron total cross sections for 182,183,184,186W isotopes calculated by using presently modified OMPs

5

6

7

Whalen+ (1966) Martin+ (1967) Foster+ (1971) Djumin+ (1977) Guenther+ (1982) Knopf+ (1987) Dietrich+ (2003) RIPL2 (Young, 1990) - mod. Young (1986)/Set II-B mod.

(a)

n + 182

W

5

6

7 Ohkubo+ (1978) #1 Ohkubo+ (1978) #2 Knopf+ (1982)


W RIPL2 (Young, 1990) -mod. Young (1986)/Set II-B - mod.

(b)

n + 183

W

0 5 10 15 20 25 30

5

6

7

Whalen+ (1966)Martin+ (1967)Foster+ (1971)Djumin+ (1977)Guenther+ (1982)Knopf+ (1982) Dietrich+ (2003) RIPL2 (Young+, 1990) - mod. Young (1986)/Set II-B mod.

(c)

n + 184

W

En (MeV)0 5 10 15 20 25 30

5

6

7

(b

)

(d)

n + 186

W Whalen+ (1966) Martin+ (1967) Foster+ (1971) Djumin+ (1977) Guenther+ (1982) Knopf+ (1982) Dietrich+ (2003) RIPL2 (Young, 1990) - mod. Young (1986)/Set II-B - mod.

En (MeV)


12

Comparison of the calculated and measured proton reaction cross sections and (p,n) reaction cross sections for 181Ta

100

1

2

(a)

p + 181

Ta

Wilkins-Igo (1963) Kirkby+ (1966) Abegg+ (1979) Perey (1963) Menet+ (1971) Koning+ (2002) Walter+ (1985) WG-Yamamuro (1988) Walter+ - mod

R

(b)

En (MeV)4 8 12

1E-5

1E-4

1E-3

0.01

0.1

(b)

181Ta(p,n)

181W

Hansen+ (1962)/T0121 Chodil+ (1967)/C0693 Thomas+ (1967)/C0695 Zhuravlev+ (1984)/A0271 Perey (1963) Menet+ (1971) Koning+ (2002) Walter+ (1985) WG-Yamamuro (1988) WG -mod

(b

)

En (MeV)

Walter-Guss (1986) - modified (local): WD=10.48-0.250E+14.94, E<10 MeV 9.55-0.157E+14.94, E>10 MeV

aD= 0.742-0.0115E, E<20 MeV 0.512, E>20 MeV


13

Nuclear Level Density

0 1 21

10

100

NUDAT (1994) BSFG

Bn=7.627, I

0=7/2

D0=0.0024(3) keV

178Hf

N (

E*)

E* (MeV)0 1 2

NUDAT (1994) BSFG

Bn=6.100, I

0=0

D0=0.057(6) keV

179Hf

Cumulative number of levels against excitation energy for, e.g., 178,179Hf, and corresponding prediction of the BSFG model


14

The -ray strength functions

0180W 182W 183W 184W 186W

RIPL-220 70(15) 62(15) 77(12) 69(17) 61(8)1040/D0 (Ref.30) 7.97(37) 45.6(8) 6.00(36) 5.51(25)0 (from Ref.30 and D0 of Ref.20) 48 55 42 470 for best normalization of fE1(E) 40 47 50 42 35

20A.V. Ignatyuk, at http://161.5.7.5/RIPL-2/resonances/ .28D.G. Gardner and F.S. Dietrich, Report UCRL-82998, LLNL-Livermore, 1979.29M. Avrigeanu, V. Avrigeanu, G. Cata, and M. Ivascu, Rev. Roum. Phys. 32, 837 (1987).30R.L. Macklin, D.M. Drake, and E.D. Arthur, Nucl. Sci. Eng. 89, 98 (1983).

• Modified energy-dependent Breit-Wigner (EDBW) model28,29: fE1(E)

• Comparison of experimental20,30 and the calculated average radiative widths- 0 (meV) used for normalization of fE1(E) capture data description


15

Comparison of calculated and measured neutron capture cross sections of 180,182-184,186W isotopes

0.01 0.1 1

0.1

1

=70+15 meV [RIPL2]

Bokhovko+ (1986)

=70 meV 55 meV 40 meV 40 meV, E

S=0

180W(n,)181

W

(b

)

1E-3 0.01 0.1 1

0.1

1 =62+15 meV [RIPL2]


S=0

Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Grenier+ (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987)

182W(n,)183

W

1E-3 0.01 0.1 10.01

0.1

1

10

=77+12 meV [RIPL2]


S=0

Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Grenier (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987)

183W(n,)184

W

1E-3 0.01 0.1 10.01

0.1

1=69+17 meV [RIPL2]


S=0

Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Joly+ (1981)Beer+ (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987)

184W(n,)185

W

(b

)

En (MeV)1E-3 0.01 0.1 1

0.01

0.1

1

En (MeV)

Bokhovko+ (1986)Knopf+ (1987)Trofimov+ (1987)Zhang+ (2001)


S=0

=61+8 meV [RIPL2]

Kononov+ (1965) Kapchigashev+(1966)Friesenhahn+ (1966)Chaubey+ (1966)Zaikin+ (1968)Diksic+ (1970)Lindner+ (1976)Gleason (1977)Bradley+ (1979)Joly+ (1981)Macklin+ (1983)

186W(n,)187

W

En (MeV)


16

Sample case of isomeric state populated by side- and continuum-decay cascade-feeding

10 12 14 16 18 201E-4

1E-3

0.01

0.1

1

E*=2.425 MeV, 21/2+ [16

th]

Greenwood+ (1987) TALYS_0.49 SH (2001) SH (2002)

94Mo(n,2n)93Mo

Fujino+ (1977) Rao+ (1979) Amemiya+ (1982) Marcinkowski+ (1986) Ikeda+ (1988) Kong+ (1995) Molla+(1997) IRMM (2001)

94Mo(n,2n)93Mom

(

b)

En (MeV)

[http://tandem.nipne.ro/~vavrig/Publications/2003/papmo_1z.ps]


17

Comparison of the measured and calculated reaction cross sections for the target nucleus 180W

Calculated values by means of the computer codes EMPIRE-II and TALYS with default global parameters (except the local OMPs) and STAPRE-H with local parameter set given in this work.

0.01 0.1 1

0.1

1

Bokhovko+ (1986)

CC+GDH+HF EMPIRE-II TALYS-0.58

(a)

180W(n,)181

W

(b)

10 15 200.00

0.01

0.02

CC+GDH+HF EMPIRE-II: g=A/14 TALYS-0.58

[1+ 8.152 h]

Qaim+ (1975)

(b)

180W(n,p)

180mTa

10 15 200

1

2

Qaim+ (1975)


(c)

180W(n,2n)

179g+mW

(b

)

En (MeV)10 15 200.0

0.4

0.8


[1/2- 6.4 min]Qaim+ (1975)Filatenkov+ (2002)

(d)

180W(n,2n)

179mW

En (MeV)


18


Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+

(1980).

1E-3 0.1

0.1

1 CC+GDH+HF EMPIRE-II TALYS-0.58

Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Grenier+ (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987) (a)

182W(n,)183

W

(b

)

10 15 200

1

2

Druzhinin+ (1966)Dilg+ (1968) Maslov+ (1972)Qaim+ (1975)Frehaut+ (1980)LNZ (1997)


(b)

182W(n,2n)

181W

10 15 200.00

0.01

0.02

(b

)

[3- 114.43 d]

Qaim+ (1975) Grallert+ (1993)LNZ (1997)Filatenkov+ (2002)


(c)

182W(n,p)

182Ta

10 15 200.0000

0.0002

0.0004

CC+GDH+HF EMPIRE-II: g=A/14

Qaim+ (1975) Kasugai+ (1992)Filatenkov+ (2002)

[10- 15.84 min]

(d)

182W(n,p)

182m2Ta

10 15 201E-8

1E-6

1E-4

Qaim+ (1975) TALYS-0.49 CC+GDH+HF

[25/2- 25.05 d]

182W(n,)

179m2Hf

Filatenkov+ (2002) CC+GDH+HF

[1/2- 18.67 s]

(e)

182W(n,)

179m1Hf

10 15 201E-12

1E-10

1E-8

1E-6

1E-4

En (MeV)

[16+ 31 y]

Hanlin+ (1994)Ikeda+ (1996)LNZ (1997)Filatenkov+ (2001) CC+GDH+HF

(f)

182W(n,n')

178m2Hf


19


Calculated values by means of the computer codes EMPIRE-II and TALYS with default global parameters (except the local OMPs) and STAPRE-H with local parameter set given in this work.

1E-3 0.01 0.1 10.01

0.1

1

10


Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Grenier (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987) (a)

183W(n,)184

W

(b

)

10 15 200.00

0.01

0.02

Qaim+ (1975) Grallert+ (1993)Filatenkov+ (2002)


(b)

183W(n,p)

183Ta

10 15 200.0000

0.0002

0.0004

CC+GDH+HF TALYS-0.58

[8- 5.5 h]

Qaim+ (1975)Filatenkov+ (2002)

(c)

183W(n,)

180mHf

(b

)

En (MeV)10 15 200

1

2


Frehaut+ (1980)

(d)

183W(n,2n)

182W

En (MeV)


20


Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+ (1980).

1E-3 0.01 0.1 10.01

0.1

1


Kononov+ (1965) Kapchigashev+ (1966)Friesenhahn+ (1966)Block+ (1966)Joly+ (1981)Beer+ (1981)Macklin+ (1983)Bokhovko+ (1986) Knopf+ (1987) (a)

184W(n,)185

W

(b

)

10 15 200.000

0.001

0.002

(c)


Qaim+ (1975) Kasugai+ (1992) Grallert+ (1993)Filatenkov+ (2002)

184W(n,)

181Hf

En (MeV)

10 15 200

1

2


184W(n,3n)

182W

Frehaut+ (1980)

(d)

184W(n,2n)

183W

10 15 200.0

0.5

En (MeV)

(b

)

Prasad+ (1966) Anders+ (1982)

[11/2+ 5.2 s]


(e)

184W(n,2n)

183mW

En (MeV)

10 15 200.000

0.005

0.010

0.015

184W(n,pn)

183Ta

Qaim+ (1975)Ikeda+ (1988)Kasugai+ (1992)Grallert+ (1993)LNZ (1997)Filatenkov+ (1999)Filatenkov+ (2002)


(b)

184W(n,p)

184Ta


21


Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set. Normalization factor of 1.078 [Vonach+, 1990] is applied to data of Frehaut+ (1980).

1E-3 0.01 0.1 10.01

0.1

1

(b

)

(a)

Bokhovko+ (1986)Knopf+ (1987)Trofimov+ (1987)Zhang+ (2001)


Kononov+ (1965) Kapchigashev+(1966)Friesenhahn+ (1966)Chaubey+ (1966)Zaikin+ (1968)Diksic+ (1970)Lindner+ (1976)Gleason (1977)Bradley+ (1979)Joly+ (1981)Macklin+ (1983)

186W(n,)187

W

(b

)

10 15 200.000

0.003

0.006

0.009

186W(n,pn)

185Ta

Coleman+ (1959)Poularikas+ (1960) Mukherjee+ (1963) Qaim+ (1975)Kasugai+ (1992)Sutoh+ (1994)Murahira+ (1995)Filatenkov+ (1999)Filatenkov+ (2002)


(b)

186W(n,p)186Ta

10 15 200.000

0.001

0.002 Qaim+ (1975)Ikeda+ (1988)Kasugai+ (1992)Grallert+ (1993)LNZ (1997)Filatenkov+ (2002)


(c)

186W(n,)

183Hf

10 15 200

1

2186W(n,3n)184W


Druzhinin+ (1966)Frehaut+ (1980) LNZ (1997)Filatenkov+ (2002)

(d)

186W(n,2n)

185W

10 15 200.0

0.5

1.0

En (MeV)

Rurarz+ (1971) Kao+ (1974)Qaim+ (1975)Filatenkov+ (1999)

[11/2+ 1.67 min]


(e)

186W(n,2n)

185mW

En (MeV)10 15 20

1E-8

1E-7

1E-6

1E-5

1E-4

[8- 61.5 min]

Filatenkov+ (2004)


(f)

186W(n,n')

182mHf

En (MeV)


22

Sensitivity of calculated (n,2n) reaction cross sections vs. reaction mechanisms & model parameters

Calculations with EMPIRE-II and default global parameters excepting local OMPs. A normalization factor of 1.078 (Vonach+, 1990) was applied to data of Frehaut+ (1980).

0

1

2


n/RIPL-2 mod., MSD/MSC n/RIPL-2 mod., DEGAS n/RIPL-2, DEGAS (a)

182W(n,2n)

181W

10 15 200

1

2

Frehaut+ (1980)

n/RIPL-2 mod., MSD/MSC n/RIPL-2 mod., DEGAS n/RIPL-2, DEGAS

(b)

183W(n,2n)

182W

0

1

2

Frehaut+ (1980)

184W(n,3n)

182W


(c)

184W(n,2n)

183W

10 15 200

1

2

En (MeV)

(b

)

(b)

186W(n,3n)

184W

n/RIPL-2 mod., MSC/MSD n/RIPL-2 mod., DEGAS n/RIPL-2, DEGAS


(d)

186W(n,2n)

185W

En (MeV)


23

Sensitivity of calculated (n,p) reaction cross sections vs. reaction mechanisms & model parameters

Calculations with EMPIRE-II and default global parameters excepting local OMPs.

0.000

0.005

0.010

[3- 114.43 d]



(a)

182W(n,p)

182Ta

(b

)

10 15 200.000

0.004

0.008


n/RIPL-2 mod., MSD/MSC n/RIPL-2 mod., DEGAS n/RIPL-2, DEGAS (b)

183W(n,p)

183Ta

(b

)

0.000

0.004

0.008

184W(n,pn)

183Ta



(c)

184W(n,p)

184Ta

10 15 200.000

0.002

0.004

En (MeV)

186W(n,pn)

185Ta



(d)

186W(n,p)186Ta

En (MeV)


24

Sensitivity of calculated (n,p) reaction cross sections vs. reaction mechanism codes

Calculations with EMPIRE-II and TALYS, and default global parameters (except local OMPs), and STAPRE-H with local parameter set.

0.00

0.01

0.02

[3- 114.43 d]



(a)

182W(n,p)

182Ta

(b

)

10 15 200.00

0.01

0.02



(b)

183W(n,p)

183Ta

(b

)

En (MeV)

0.000

0.005

0.010

0.015



(c)

184W(n,p)

184Ta

10 15 200.000

0.005

0.010

Coleman+ (1959)Mukherjee+ (1963) Qaim+ (1975)Kasugai+ (1992)Sutoh+ (1994)Murahira+ (1995)Filatenkov+ (1999)Filatenkov+ (2002)

CC+GDH+HF EMPIRE-II TALYS-0.58(d)

186W(n,p)186Ta

En (MeV)


25

Sensitivity of calculated reaction cross sections vs. model parameters (s.p.l. g = A/13 - A/15 MeV-1)

Calculations with EMPIRE-II and default global parameters excepting local OMPs and the s.p.l. value. A normalization factor of 1.078 (Vonach+, 1990) was applied to data of Frehaut+ (1980).

10 15 200.000

0.005

0.010

0.015

[3- 114.43 d]


EMPIRE-II: g=A/13 g=A/14 g=A/15

(a)

182W(n,p)

182Ta

(b

)

10 15 200

1

2



(e)

182W(n,2n)

181W

(b

)

10 15 20



(b)

183W(n,p)

183Ta

10 15 20


Frehaut+ (1980)

(f)

183W(n,2n)

182W

10 15 20



(c)

184W(n,p)

184Ta

10 15 20


184W(n,3n)

182W

Frehaut+ (1980)

(g)

184W(n,2n)

183W

En (MeV)

10 15 20



(d)

186W(n,p)186Ta

10 15 20

186W(n,3n)

184W



(h)

186W(n,2n)

185W


26

Conclusions• Achievements

- Appropriate optical model potentials: n+182,183,184,186W- Unitary description of all activation experimental data (E<20 MeV) by using a

local parameter set in STAPRE-H code- Good results of blind calculations and global parameters within EMPIRE-II

and TALYS codes- Similar sensitivity of calculations vs. reaction mechanisms & model

parameters

• Problems- Major uncertainty of calculated isomeric cross sections: level schemes &

branching ratios

- (n,p)-, (n,)-reaction excitation functions at En>15 MeV

• Completion - Similar analysis for: n+180,181Ta, n+174,176,177,178,179,180Hf

- Need for - (n,p)-, (n,)-reaction data at En>15 MeV (e.g., JRC/IRMM) - (n.d ) reaction data (emission spectra, e.g., LLNL-

Livermore)

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V. Avrigeanu - Workshop on Activation Data (EAF-2005), Prague, June 7-9, 2004 1 Progress Report on...

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