Transformation and improvements of EAF-2003 for EAF-2005

Transcription

1 EAF-2005 workshop Prague Transformation and improvements of EAF-2003 for EAF-2005 J. Kopecky and R. Forrest JUKO Research and UKAEA Culham Science Center

2 Outline of the talk 1. EAF-2004 experience with extension of data up to 60 MeV. Survey of experimental data above 20 MeV. 2. Low energy improvements (< EH) for Q>0 reaction channels (non-threshold data). 3. Some revisions in application of cross section systematic for excitation curve renormalizations.

3 1. EAF-2004 conclusions EAF-2004 assembled from EAF-2003 (<20MeV) and TALYS-4 (>20MeV) /see R. Forrest EFF-Doc-881/. To test assembling, processing (SAFEPAQ-II) and calculation procedures (FISPACT) for extended energy range library have been tested. FISPACT test calculations of Eurofer demonstrated the importance of <20 MeV cross sections for IFMIF like neutron spectrum.

4 Preliminary IFMIF calculation * Irradiation of Eurofer steel for five years in the high flux test region (HFTM) of IFMIF * All neutrons (211 groups) - flux = 7.5x10 14 ncm -2 s -1 * No neutrons > 20 MeV (175 groups) - flux = x10 14 ncm -2 s - 1 (6.5% removed) * At times up to 10 years there is a difference of about 40% between the two cases, dropping to about 18% at 10,000 y * Same dominant nuclides, but more of each nuclide has been formed in the 211-group case * Due both to high-energy neutrons increasing the contribution of existing reactions and to new reactions becoming important at the higher energies

5 Eurofer irradiated in an IFMIF spectrum 1.0E E+14 Mn 56 Cr 51 Mn 54 Fe E+13 H 3 1.0E E E E groups 175 groups Nuclides Ni 63 C E+08 Nuclides Nb E E E E E E E E E E+04

6 Contributions to nuclide production Reaction Threshold (MeV) Activity at shutdown (Bq) groups Activity at shutdown (Bq) groups 54 Fe(n,p) 54 Mn (97.5%) (62.7%) 56 Fe(n,p) 56 Mn (99.0%) (96.0%) 56 Fe(n,pα) 52 V (5.0%) 56 Fe(n,2n) 55 Fe (99.4%) (98.0%) 56 Fe(n,t) 54 Mn (35.1%) 54 Fe(n,dα) 49 V (7.4%) 57 Fe(n,3n) 55 Fe (1.6%) 56 Fe(n,2nα) 51 Cr (5.8%) 50 Co(n,3α) 39 Ar (13.4%) 183 W(n,5n) 179 W(β + ) 179 Ta (3.1%)

7 EAF-2005 pending actions Survey of MeV differential experimental data (internal EAF-Doc-33). Search for existing integral measurements.

8 EAF-Doc-33 (April 2004) Introduction This report describes the search for experimental data between 20 MeV and 60 MeV. The primary source of these data was EXFOR-03 CD-Rom from NEA Data Bank. Some additional data sources from Tohoku University, not included in EXFOR data base, have been checked and added as Private EXFOR. Three groups of data have been identified: Differential data, measured primarily by activation techniques and in few cases by particle counting. At this moment we have found such data for 134 reactions. All these data have been graphically compared against available evaluations, FINAL (EAF < 20 MeV), IAEF-2001 from KfK, MENDL-2 and WIND from Obninsk and finally TALYS-4.

9 EAF-Doc-33 (April 2004) Other kind of data could be identified as integral data. They have been measured at KfK Juelich in late seventies by S. Qaim et al., using breakup of 53 MeV deuterons on a Be target. The resulting neutron spectrum extends from 4 to 50 MeV, with its maximum around 22.5 MeV and FWHM = 15.8 MeV. In case of an accurate enough description of this spectrum, the data can be analysed as integral data. We expect to obtain the description of d-be spectra from the authors shortly. Finally pseudo-integral data, the main use of these data was to adjust the excitation curve, starting from an calculated prior, with the aim to provide dosimetry reaction standards for spectra above 20 MeV. However, we have scanned these data too, because their integral activity can be used to test EAF adopted excitation curves against these data, again with the condition of known applied neutron spectra. Collaboration JAERI and KfK (Maekawa, Moellendorf).

10 20-60 MeV survey Two kind of differential measurements: Full MeV scale measurements, coming from two laboratories: Louvain-La- Neuve and Tohoku University activation measurements with the Li-7(p,n) neutron source. Just above 20 MeV measurements (activation measurements), data mostly between MeV.

11 20-60 MeV survey Plotting compatibility of single reaction channel (relevant < 20 MeV, weak < 20 MeV) and lumped reaction channels: (n,d)+ = (n,d) + (n,n p) (n,t)+ = (n,t) + (n,n d) + (n,2np) + (n,h)+ = (n,h) + (n,n t) + (n,pd) + (n,n 2p) + (n,a)+ = (n,a) + (n,n h) + (n,pt) + (n,2d) + (n,n a)+= (n,n a) + (n,2nh) + (n,n pt) + (n,n 2d) +

12 Al-27(n,a)Na-24 Cross section (b) 2.0E E E E E-02 Systm MIM89 PAT80 AEP89 AEP93 BUC92 MIM89 SST87 DEB98 BNU97 CAB00 IFS83 m OHO81 JAE91 g LVN00 ANL87 ANL87 HAR83 KOS82 CHM86 KOS86 JAE93 TSU84 BIR76 IFS83 KOS80 AEP89 ANL89 KOS86 RI 97 FEI89 IRK81 BUC74 0.0E E E E E E E E+07 Energy (ev) TALYS-4 Final

13 Al-27(n,2p)Na E-03 Systm LVN00 8.0E-03 Cross section (b) 6.0E E E E E E E E E E E+07 Energy (ev) Final TALYS-4 MENDL-2 IEAF-2001

14 Co-59(n,2n)Co-58 Cross section (b) 1.0E E E E E-01 Systm NPL88 m BUC92 KHA96 PTB94 g RI 99 ARK60 m KTO90 g POO91 KTO88 KIG84 m KIG84 g ARK60 g RI 99 g IEN97 MOH82 m IRK86 MOH84 m ANL87 TOH96 GEL03 m MOH84 g RAM94 GEL01 m GEL01 TOH99 RI 97 m RI 99 m BRC02 BJG90 JAE84 g GEL01 GEL01 GEL03 JAE88 AEP89 AEP89 0.0E E E E E E E E+07 Energy (ev) Final MENDL-2 IEAF-2001 TALYS-4

15 Au-197(n,2n)Au-196 Cross section (b) 2.5E E E E E-01 Systm KTO90 g AUB82 n AUB84 n KTO88 SIU02 n PIT84 BUC92 NPL81 g IBJ84 g MOH82 g BRC81 n BRC81 g SIU89 KOS00 FEI83 ANL87 TOH92 n TOH92 g AUB84 n KRI02 KRI02 n KOS82 AEP89 RI 99 RI 99 n LAS61 n LAS61 LAS77 JAE88 g JAE88 n JAE84 LAS75 BRC02 LRL60 n LRL60 g GEL75 0.0E E E E E E E E+07 Energy (ev) TALYS-4 MENDL-2 Final IEAF-2001

16 Bi-209(n,4n)Bi-206 TOH98 1.5E E+00 Cross section (b) 9.0E E E E E E E E E E E+07 Energy (ev) TALYS-4 IEAF-2001 MENDL-2 Final

17 Just above 20 MeV data points Nb-93(n,2n)Nb-92 Cross section (b) 2.0E+00 Systm RBZ76 GEL70 MUN71 KTO88 m KTO90 m 1.6E+00 TUD73 RBZ76 g SEO86 m CIP85 m PIT84 RI 99 m KGU80 ANL91 m 1.2E+00 ALD72 FEI84 JAE91 m KOS 0 m AEP98 m JUL88 m GEL00 m 8.0E-01 SAV89 m RAM91 m KGU77 SIU89 m JAE93 m LAS77 JAE84 m JAE88 m 4.0E-01 LRL72 m BRC02 CRC90 m AEP89 m GEL88 m AEP84 m RI 97 m 0.0E+00 GEL87 m CRC90 m 0.0E E E E E E E+07 Energy (ev) Final MENDL-2 IEAF-2001 TALYS-4

18 Just above 20 MeV data points Cross section (b) 2.5E E E E+00 Tm-169(n,2n)Tm-168 Systm LAS75 JUL74 BRC81 ALD72 ANL87 AUB73 LAS75 SIU89 LRL72 LAS77 LAS75 BRC02 AEP89 5.0E E E E E E E E E+07 Energy (ev) Final IEAF-2001 MENDL-2 TALYS-4

19 Single Just above 20 MeV data point 2.5E E+00 Tl-203(n,2n)Tl-202 Systm JAE81 CCP71 LOU73 DEB68 KIG91 MUN68 GIT72 DEB01 LAS75 LAS75 BRC80 BRC02 Cross section (b) 1.5E E E E E E E E E E E+07 Energy (ev) Final IEAF-2001 MENDL-2 TALYS-4

20 Cross section (b) 1.0E E E E-01 Ni-58(n,d+np)Co-57 Systm JAE88 SAV00 KLN75 ARK63 SLO85 IPJ85 KHA96 TIL90 TIL92 EPA72 AEP94 NDL68 MOH82 RAB91 AEP98 IRK85 GEL02 IRK85 2.0E E E E E E E E+07 Energy (ev) Final IEAF-2001 MENDL-2 TALYS-4

21 Just above 20 MeV data points Cross section(b) 1.0E E E E-01 Ni-58(n,d+np)Co-57 Systm JAE88 SAV00 KLN75 ARK63 SLO85 IPJ85 KHA96 TIL90 TIL92 EPA72 AEP94 NDL68 MOH82 RAB91 AEP98 IRK85 GEL02 IRK85 2.0E E E E E E E E+07 Energy (ev) Final IEAF-2001 MENDL-2 TALYS-4

22 Merging problem at 20 MeV Nb-93(n,3n)Nb-91 LAS77 1.0E E-01 Cross section (b) 6.0E E E E E E E E E E E+07 Energy (ev) MENDL-2 IEAF-2001 TALYS-4 Final

23 Merging problem at 20 MeV Nb-93(n,3n)Nb-91 LAS77 7.5E E-01 Cross section(b) 4.5E E E E E E E E E E E E E E+07 Energy (ev) Final TALYS-4 TALYS-5 EAF

24 2. Low energy improvements Single Resonance Approximation (SRA) applied for (n,g) and (n,f) reactions with no experimental resonance data. It replaces a part of 1/v and unresolved resonance region in the vicinity of EH by a BW single resonance. Low Energy Approximation (LEA) the low energy description introduced which represents the region below the effective threshold of (n,p) and (n,α) reactions with Q > 0 by the resonance data (if available) and or pure 1/v (if no resonance exist).

25 Single resonance approximation Single Resonance Approximation (SRA) Based on the assumption that one strong resonance is responsible for a large thermal cross section. Single- Level Breit-Wigner formula is used to fit the experimental thermal cross section σ(n,γ), for a chosen resonance energy E0 (free parameter between realistic EV and EH) and Γγ taken from tabulated data base (spline fit to experimental data) and Γn calculated from the SLBW equation. The procedure is repeated to fit Iγ in the best way.applied only for large σth >10 b.

26 Single resonance approximation 1.0E E+00 Systm Sys30 PNC92 CRC93 BNW83 Sr-90(n,g)Sr-91 EAF-2003 uses SRA 1.0E-01 Cross section (b) 1.0E E E-04 Resonance Integral Exp: 160 mb EAF-2001:19.8 mb EAF-2003: 164 mb 1.0E E E E E E-011.0E+001.0E+011.0E+021.0E+031.0E+041.0E+051.0E+061.0E+07 Energy (ev) Final EAF

27 < 20 MeV improvements Low Energy Approximation (LEA) the low energy description introduced in TALYS and extended and tested in SAFEPAQ-II. It represents the region below effective threshold of (n,p) and (n,α) reactions with Q > 0 in a best physical way. It is based on the assumption that the ratio R = σ(p)/σ(γ) or σ(α)/σ(γ) is at low energies (kev region) constant. This is supported by nuclear model calculations, e.g. in TALYS. Further a similar distribution of Γp,α as Γγ is assumed.

28 Calculated (n,p)(n,α)/(n,γ) cross section ratio R with TALYS as a function of neutron energy

29 Experimental Γ(p) used to construct resonance region 1.0E+03 Cl-35(n,p)S E E+01 Cross section(b) 1.0E E E E E E E E E E E E E E E E E E+07 Energy (ev) Final Experimental data

30 Experimental Γ(p) used to construct resonance region Cl-35(n,p)S-35 Cross section (b) 1.0E E E E E E-02 Systm DUB96 CCP75 KAZ63 GEL94 IRK70 AMS66 HAR61 NBS68 PSU66 CPO69 CPO69 LEB61 LAS91 1.0E E E E E E E E E E E E E E E+07 Energy (ev) Final

31 Experimental Γ(p,α) used to construct resonance region Ni-59(n,p)Co-59 Ni-59(n,a)Fe E E+01 Systm ILL77 CTH76 ORL80 TOH94 1.0E E+02 Systm CTH76 ORL80 CRC75 CRC75 KAP74 Cross section (b) 1.0E E-01 Cross section (b) 1.0E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E+07 Energy (ev) Final Energy (ev) Final

32 LEA applied Cl-35(n,p)S E E E+01 Cross section(b) 1.0E E E E E E E E E E E E E E E E E E E E+07 Energy (ev) EAF Final Experimental data

33 LEA applied res. region Cl-35(n,p)S E E E+01 Cross section(b) 1.0E E E E E E E E E E E E+05 Energy (ev) EAF Final Experimental data

34 Earlier < 20 MeV improvements LEA first used in evaluations by H. Gruppelaar in Co-58 (n,p) and Co-58(n,γ) JEF-2 evaluation. The measured thermal absorption cross section was split in (n,p) and (n,γ) by applying the factor R. Later, a modified manner was applied in JENDL-3 for several deformed targets. Here, adjustable <Γ p > or <Γ α > instead of <Γ γ > in MF2 were used to reproduce σ th (n,p), σ th (n,α) with a group structure of resolved resonance data.

35 JENDL approach Eu-151(n,a)Pm E E-03 Systm KOS97 g AUW69 m JUL74 LYO74 RI 99 g RI 99 m Cross section (b) 1.0E E E E E E E E E E E E E E E E E E+07 Energy (ev) Final

36 EAF < 20 MeV improvements TALYS calculations down to 1 kev merged with: RR(n,g) + s th (exp),(n,p),(n,a) for 71 reactions; RR(n,g) + s th (n,p),(n,a) estimated from s th (n,g) * R for 231 reactions; the rest (no exp. information) taken directly from TALYS calculations.

37 Bi-209(n,a)Tl E E E-03 Cross section (b) 1.0E E E E E E E E E E E E E E E E E E+07 Experimental data Energy (ev) ENDF/B-VI.8 JENDL-3.3 JENDL-3.2/A ADL-3 EAF

38 Bi-209(n,a)Tl E E E-03 Cross section (b) 1.0E E E E E E E E E E E E E E E E E E+07 Experimental data Energy (ev) TALYS-4 ENDF/B-VI.8 JENDL-3.3 JENDL-3.2/A ADL-3 EAF EAF

39 Bi-209(n,a)Tl E E E-03 Cross section (b) 1.0E E E E E E E E E E E E E E E E E E+07 Experimental data Energy (ev)

40 Ho-165(n,a)Tb E E-03 Cross section (b) 1.0E E E E E E E E E E E E E E E E E E+076.0E+07 Energy (ev) Final TALYS-5 Experimental data

41 3. Cross Section Systematics Many cross section systematics have been developed during last 15 years by many authors, in particular at neutron energy of 14.5 MeV. They usually display the cross section dependence on S = N-Z/A and A as a polynomial or exponential function. They are of a high quality and can be used as an additional pseudo-experimental information to represent the trend of cross sections for the following reaction channels: (n,2n), (n,n p), (n,p), (n,d),(n,h), (n,α) and further (n,d+n p) and (n,t+n d).

42 Cross Section Systematic Some new systematic or their improvements have been developed in the coarse of EAF project, for the following reactions: 1. (n,γ) at En = ev, 30 kev and 14.5 MeV 2. (n,n α) at En = 14.5 MeV 3. (n,2p) at En = 14.5 MeV 4. (n,n p+d) at En = 14.5 MeV

43

44

45 (n,n a) systematic Problems: *Old systematic σ(n,n'α) = 0.1 σ(n,α) *C/S very broad *EXFOR 22 references Q < 14.5 MeV *New systematic σ(n,n'α) = e (-24.2s), not applied in EAF-2001 *No significant improvement

46

47 Systematics at 14.5 MeV: (n,n'a) reactions 668 FS=99 values N um ber of reactions Num ber of reactions E-03 1E-02 1E-01 1E+00 1E+01 1E+02 1E+03 C/S value 0.0 1E-03 1E-02 1E-01 1E+00 1E+01 1E+02 1E+03 C/S value

48 Problems: (n,2p) systematic *Difficult to measure, many EXFOR references with no error or as upper limits *New systematic σ(n,2p) = e (-2.99s), not applied in EAF-2003 *Broad C/S distribution *Integral experiment provided important information *Systematic finally used as upper limit only

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50 Integral experiment helps Si-29(n,2p)Mg-28 Systm ARK63 Integral C/E for Si-29(n,2p)Mg E E E Cross section (b) 1.0E E E-07 C / E E E-09 C/E = E E E E E E E+07 Energy (ev) ADL-3 JENDL-3.3 TALYS-4 Final 0.30 fzk_1 Neutron Spectrum 0.33

51 Problems: (n,n p+d) systematic *Single reaction channel experimental data are only σ(n,d) for targets with A < 100 (deuteron detection) or lumped σ(n,n p+d) in the whole mass range (activation technique). *Influence of Q(n,n p) if > or < Q(n,2n) on σ(n,n p) *Problem with splitting of (n,n p+d) and (n,d) above A = 100.

52 (n,n p+d) systematic (cont.) Problems: *New (n,d) systematic from IPPE Obninsk adopted fro targets with s > Provides more realistic split between (n,n p) and (n,d). *Explains the broad C/S distribution.

53 Sn >Sp nd Sp >Sn

54 Systematics at 14.5 MeV: (n,n'p) reactions 752 FS=99 values 50 Number of reactions E-03 1E-02 1E-01 1E+00 1E+01 1E+02 1E+03 C/S value

55 RN SYS revisions Renormalization to cross section systematic is a standard modification in many evaluations. In particular RN-SYS at 14.5 MeV has been often used. However, this procedure has to be applied with caution, if 14.5 MeV is not close to the maximum of the excitation curve (Q is close to 14.5 MeV) and especially for excitation curves in a broad energy range (e.g. 60 MeV).

56 RN SYS revisions Three groups of excitation curves: σ(max) << 20 MeV, close to 14.5 MeV and Q <<14.5 MeV: (n,2n), (n,p), (n,α), (n,np) RN-SYS σ(max) 20 MeV, Q < 14.5 MeV but Qeff (= Q+CB) is close to 14.5 MeV and the steep slope of the excitation curve is near 14.5 MeV: (n,d), (n,t), (n,np), (n,nα) RN-SYS?? σ(max) 20 MeV, Q ± 14.5 MeV and the steep slope of the excitation curve is at 14.5 MeV: (n,t), (n,h) RN-SYS??

57 σ(max) + 14 MeV Nd-145(n,a)Ce-142 Systm 1.0E E-02 Cross section(b) 1.0E E E E E E E E E E+07 Energy (ev) TALYS-4

58 Q=13.09 MeV + CB σ(max) > 20 MeV P-31(n,h)Al-29 Systm RBZ74 KIG85 ARK62 1.0E E E-04 Cross section (b) 1.0E E E E E E E E E E E E E+07 Energy (ev) FEI JENDL-3.2/A TALYS-4 ADL-3

59 COMPLETED ACTIONS: Conclusions Survey of EXFOR data in the MeV completed. A preliminary report (EAF-Doc-33) prepared as a starter for the future validation report of EAF-2005 in this energy range. LEA introduced in SAFEPAQ-II, tested and applied for 80 (n,p), (n,α) reactions with known thermal (n,p), (n,α) cross sections and resolved resonance regions in (n,γ). New 14.5 MeV systematic formulae adopted for (n,d) and (n,t) reactions. Calculated systematic at 20 MeV (IPPE Obninsk) introduced in SAFEPAQ-II for future validation at the merge energy of 20 MeV.

60 Conclusions FUTURE ACTIONS (before 12/2004): Completion of the final validation report of all 134 reactions provided with differential experimental data against EAF-2005 excitation curves. Completion of the remaining LEA modifications for reactions (=210) with resolved resonance region in (n,γ) and thermal (n,p), (n,α) cross sections derived from TALYS calculations. New 3-groups structure for uncertainties for (n,p), (n,α) with Q > 0. Application of new and revision of all previous RN- SYS modifications within all EAF-2005 data with the emphasis on extended energy region above 20 MeV.