1. Alpha-particle optical model potentials within
Vlad Avrigeanu
Vlad Avrigeanu
Workshop LEA NuAG – SPIRAL2-CZ - CANAM
Praga, Czech Republic, May 3-5, 2017
Horia Hulubei National Institute for Physics & Nuclear Engineering, Bucharest, Romania
Alpha-particle optical model potentials within
consistent analysis of fast-neutron induced reactions
on Zr isotopes
Vlad Avrigeanu and Marilena Avrigeanu
Horia Hulubei National Institute for Physics & Nuclear Engineering (IFIN-HH), Bucharest, Romania
On the topics:
[ Introduction - consistent model calculations: method, tools, (R)IP(L3) ]
(a,g), (a,n), (p,a), reaction analysis at E≤ B [ Astrophysics & EUROfusion ]
(p,g), (p,n), (n,g) reaction analysis
(n,a) reaction analysis [ Neutron activation of ,94,96Zr ]
[ Conclusions ]
Vlad Avrigeanu
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017 1
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
4th Association EURATOM-MEdC Days Meeting, Ramnicu Valcea, 1

2. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
1.1 Method, tools, IP [Nuclear data consistent model calculations]
[ E.D. Arthur – P.G. Young, LANL, ’80 ]
[ e.g., Nucl. Sci. Eng. 76, 137 (1980) ]
[ IAEA/NDS RCs (12), Bucharest, ]
YES
unitary use of common model parameters for different mechanisms
use of consistent sets of input parameters - determined by analyses of various independent experimental data
unitary account of whole body of related experimental data for isotope chains and neighboring elements
[ activation & particle-emission spectra ]
[ enlarged incident-energy range ] NO
re-normalization or free parameters, widely-used within ND libraries, e.g.:
EFFDOC-1288:
(NRG-Petten)
EFFDOC-1289:
(KIT-Karlsruhe)
Vlad Avrigeanu 2
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

3. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
Vlad Avrigeanu
Horia Hulubei National Institute for Physics & Nuclear Engineering, Bucharest, Romania
1.1 Method, tools, IP
OPTICAL MODEL : prime tool for all cross section calculations
Phenomenological OMP (global parameter sets): still extensively used
Microscopic OPs: reduced uncertainties (e.g., OM ambiguities)
Phys. Rev. C62 (2000)
Nucl. Phys. A693 (2001) 616
Eur. Phys. J. A12 (2001) 399
Int. J. of Mod. Phys. E, 11 (2002) 249
Nucl. Phys. A723 (2003) 104
Nucl. Phys. A 759 (2005) 327
Nucl. Phys. A 764 (2006) 246
Pure elastic scattering OP analysis
SCAT2 [O. Bersillon]
- phenomenological OP
+ semi-microscopic (DF) OP
(local version)
Coupled Reaction Channel (CRC)
FRESCO [I.J. Thompson]
Composite system equilibration
- Geometry Dependent Hybrid (GDH) preequilibrium-emission model
- Hauser-Feshbach (HF) statistical model
STAPRE-H95 [V. Avrigeanu, M. Avrigeanu]
(updated)
0. Concerning the nuclear-model calculations actually involved in the nuclear data evaluations,
1. The OM is a prime tool. However, there are still extensively used – IN THE CASE OF ALPHA-PARTICLES - the phenomenological OMPs,
while it is known that the involvement of microscopical potentials would reduce really the uncertainties of the OMP parameter sets.
2. The computer codes used in order to obtain the results shown in this presentation are, first, SCAT2 for pure elastic scattering,…
3. …second, a local (NIPNE-Bucharest) code for usinf the DFM, with results …
4. …described in …
5. …a series of papers.
6. At the same tine it has been also used the CRC code FRESCO for elastic-transfer consideration.
7. Finally, some of the discussed OMP have been involved in PE+HF calculations with our local code STAPRE-H, which includes also SCAT2
for calculations of OM transmission coefficients, while the same OMP parameters are involved in the PE description in the frame of the GDH
model for description of the intranuclear transition rates.
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

4. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
1.1 Method, tools, IP
LOCAL APPROACH:
STAPRE-H95 (updated-2014) [OM/PE/SM: SCAT2, GDH, HF]
neutron- spherical OMP [Koning-Delaroche, Nucl.Phys. A713, 231 (2003)]
p-, a- spherical OMP: [Johnson+ (1968), V. Avrigeanu+, PRC 49, 2125 (1994),
V. Avrigeanu+, PRC 90, (2014)]
g-ray strength functions: E1[EGLO/OCL:PRC 93,045810(2016), ibid. 94,025804(2016)]
M1(SLO, 1990 [RIPL-1])
PE: Geometry Dependent Hybrid model [M. Blann+, PRC 28, 1493 (1984)]
+ a-particle emission [Z.Phys. A 329,177(1988)]
+ Jp-conservation [Z.Phys. A 329,177(1988)]
+ gFGM(e), AK(p,h), fK(p,h,E,F1(l,Ei) [Phys. Rev. C 58, 295 (1998)]
Nuclear-level density (E>Ed [ENSDF]): BSFG:
+ E*<Bn: (a,D) from fit of [D0 (RIPL-3), Nd (ENSDF,RIPL3)]
+ E*>Bn: a(E*) [A.R. Junghans+, NPA629, 635 (1998);
A.J. Koning, M.B. Chadwick, PRC 56, 970 (1997)]
+ I/Ir: 0.5(g.s.)-0.75(Bn)-1(15 MeV) [ V.Avrigeanu+, JNST S2,746 (2002)
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

5. 2. The a-particle emission:
F4E-GRT
F4E-GRT
F4E-GRT
arXiv:
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

6. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
2.1 HF analysis (a,g): based on RSF data (A ~ )
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

7. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
2.2 HF analysis (a,g), (p,g): based on RSF data (A ~ 60-70)
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

8. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
2.2.2 HF analysis (a,x), (p,g), (p,n), (p,a): A ~ 60-70
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

9. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
2.3 HF analysis (a,g), (p,g): based on RSF data (A ~ 60)
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

10. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
2.4 HF analysis (a,g), (p,g): based on RSF data (A ~ )
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

11. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
3.1 HF analysis (n+Zr): RSF/OMP(p) vs. s(p,g) , s(p,n)
EFFDOC-1314
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

12. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
3.2 HF analysis (n+Zr): RSF vs. s(n,g) : 89Y, 90-92,94,96Zr
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

13. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
Vlad Avrigeanu
Horia Hulubei National Institute for Physics & Nuclear Engineering, Bucharest, Romania
4. Consistent analysis of reactions 90,91,92,94Zr(n,x), En<22 MeV
EFFDOC-1299
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

14. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
4.1 HF+PE analysis: reactions (n,2n) , (n,xp) on, e.g., 90,96Zr, En<22 MeV
EFFDOC-1314
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

15. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
4.2 Results for (n,a) reactions on 90,94Zr, En<22 MeV:
EFFDOC-1299
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

16. Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017
4.3 Results for (n,a) reactions on 92,96Zr, En<20 MeV:
OMPs basic differences:
- AHA (1994) [Nolte+ (1887) extrapolation down]:
- A+(2014) [s(a,x), Ea<B; dsa,a/dW, Ea>B]: WD~4, 4+..., WV=0, Ea<B  ?
a-absorption (E<B): at surface
(n,a) - emission (E<B): in volume
PRC 91, (2015): [ (p,a) – emission (E<B): at surface ]
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017

17. Thank you for your attention !
5. Conclusions
Consistent RSF: consistent (n,g), (p,g), (a,g), (a,p) cross sections
Consistent analysis of (n,x) reactions on 90,91,92,94,96Zr (to be published)
(n,a) analysis:
PRC 91, (2015): [ (p,a) – emission (E<B): at surface ] ?
Open Questions (?)
Additional (n,a) & (p,a) reaction c.s. consistent analysis
Additional (n,a) & (n,an) reaction c.s. consistent analysis ? ?
Thank you for your attention ! 17
Vlad Avrigeanu
Workshop LEA NuAG - SPIRAL2-CZ - CANAM, May 3-5, 2017