Photonuclear Activation File. Status and Perspectives

Transcription

1 Photonuclear Activation File ((( P A F ))) Status and Perspectives M-L. Giacri, A. Vanlauwe, J-C. David, D. Doré, D. Ridikas, I. Raskinyte, E. Dupont, V. Macary CEA Saclay, DSM/Dapnia/SPhN In collaboration with LANL, GSI, CEA-DAM, -DRT, -DEN Workshop on Activation Data EAF2007, October 2006, Prague 1

2 Motivations Physics Access to unique composite nucleus (e.g. 232 Th, 238 U, ) γ-fission n-fission process Production of neutrons and RIB Nuclear Energy Nuclear waste transmutation-incineration Active interrogation of nuclear waste Safety & Shielding Detection of fissionable materials Shielding of electron accelerators Decommissioning of nuclear installations Workshop on Activation Data EAF2007, October 2006, Prague 2

3 Activities at CEA Saclay Applications: Nuclear waste characterization Calculation of material activation PAF Modelling: XS: photo-nuclear reaction cross sections FY: photo-fission fragment distributions DN: photo-fission delayed neutrons Experiments: DN: photo-fission delayed neutrons Workshop on Activation Data EAF2007, October 2006, Prague 3

4 Application Characterization of Nuclear Wastes Conversion target Prompt neutrons (PN) (γ,n), (γ,2n), (γ,fiss) actinides electrons photons Delayed neutrons (DN) Y(A,Z) β - -n Delayed photons (DP) Y(A,Z) β - - γ Workshop on Activation Data EAF2007, October 2006, Prague 4

5 Application Calculation of material activation n, γ, Photonuclear Activation File Workshop on Activation Data EAF2007, October 2006, Prague 5

6 M-L. Giacri PAF Photonuclear Activation File collaboration with LANL & GSI Photonuclear Activation File Status: x-sections for nuclei with Z < 89 (~500 isotopes included) x-sections for nuclei with Z 89 (all actinides included) insertion of fission products (done for Th, U, Np and Pu isotopes) construction of delayed neutron tables (done for Th, U, Np and Pu isotopes) Workshop on Activation Data EAF2007, October 2006, Prague 6

7 M-L. Giacri IAEA Evaluations 164 nuclei for various applications (medicine, neutron production, ) Evaluations mainly based on experimental data Best (complete, accurate) evaluations are selected 133 Cs (γ,abs) 235 U Workshop on Activation Data EAF2007, October 2006, Prague 7

8 M-L. Giacri XS HMS-ALICE Calculations for Z < 89 Input: (A, Z, E γ ) Output: (γ,tot), (γ,n), (γ,2n), (γ,p), (γ,fiss), Comparison: IAEA data (solid) versus HMS-ALICE (dashed) 30.0 γ + 27 Al 800 γ Pb Cross section (mbarn) σ(γ,1n) IAEA σ(γ,1n) HMS ALICE σ(γ,1p) IAEA σ(γ,1p) HMS ALICE Cross section (mbarn) σ(γ,1n) IAEA σ(γ,1n) HMS ALICE σ(γ,2n) IAEA σ(γ,2n) HMS ALICE Energy (MeV) Energy (MeV) Workshop on Activation Data EAF2007, October 2006, Prague 8

9 Application Decommissioning of LURE Analysis of concrete samples from the walls Activation calculations with MCNP + CINDER 90 + PAF Workshop on Activation Data EAF2007, October 2006, Prague 9

10 M-L. Giacri XS HMS-ALICE Calculations for Actinides Absorption cross section 235 U 235 U photoabsorption IAEA HMS ALICE Cross section (mbarn) HMS-ALICE RIPL2 Caldwell data (1980) Gurevich data (1976) Cross section (mbarn) U IAEA HMS ALICE Pu Energy (MeV) Improvement of the total photoabsorption cross section for actinides IAEA HMS ALICE Energy (MeV) Workshop on Activation Data EAF2007, October 2006, Prague 10

11 M-L. Giacri XS HMS-ALICE Calculations for Actinides 238 U 235 U Good results but more accurate evaluations requested for major actinides Calculations using the GNASH code Workshop on Activation Data EAF2007, October 2006, Prague 11

12 M-L. Giacri XS GNASH Evaluations for 235 Input: (A, Z, E γ ), σ abs, Output: (γ,n), (γ,2n), (γ,fiss) 235 U, 239 Pu Cross section (mbarn) GNASH Evaluation 235 U (γ,1n) calc. (γ,2n) calc. (γ,fiss) calc. Caldwell data (1980) Varlamov data (1987) 235 U Cross section (mbarn) GNASH Evaluation 239 Pu (γ,1n) calc. (γ,2n) calc. (γ,fiss) calc. Caldwell data (1986) Moraes data (1993) 239 Pu Energy(MeV) Energy (MeV) Validation of GNASH for low energy photon induced reactions on actinides Workshop on Activation Data EAF2007, October 2006, Prague 12

13 M-L. Giacri XS GNASH Evaluations for 238 Input: (A, Z, E γ ), σ abs, Output: (γ,n), (γ,2n), (γ,fiss) Cross section (mbarn) n, GNASH calc. Bermann, Caldwell (1986) Veyssiere (1973) 2n, GNASH calc. Bermann, Caldwell (1986) Veyssiere (1973) 238 U, 237 Np γ p 237 Np Cross section (mb) Caldwell (1980) Veyssière (1973) Varlamov (1987) (γ,1n) GNASH (γ,2n) GNASH (γ,f) GNASH 238 U Cross section (mbarn) Energy (MeV) F, GNASH calc. Bermann, Caldwell (1986) Veyssiere (1973) Soldatov (1992) Zhuchko (1978) (γ,fiss) 237 Np Photon Energy (MeV) Energy (MeV) Workshop on Activation Data EAF2007, October 2006, Prague 13

14 M-L. Giacri XS GNASH Evaluations for Am, 240 Pu Input: (A, Z, E γ ), σ abs, Output: (γ,n), (γ,2n), (γ,fiss) Cross section (mb) Am (γ,fiss) (γ,n) (γ,2n) GNASH (γ,fiss) Soldatov (94) Korestaya (79) Findlay (92) GNASH (γ,1n) GNASH (γ,2n) Cross section (mb) Pu GNASH (γ,fiss) Soldatov (97) GNASH (γ,1ν) GNASH (γ,2n) Photon Energy (MeV) Photon Energy (MeV) All ENDF formatted, thanks to P. Young (T-16, LANL) All adopted in ENDF/B-VII(β): 235 U, 238 U, 237 Np, 239 Pu, 240 Pu & 241 Am Workshop on Activation Data EAF2007, October 2006, Prague 14

15 M-L. Giacri XS GNASH vs. Integral Data for Am, 237 Np R fiss ( 241 Am) / R fiss ( 238 U) E max (MeV) GNASH Experiment 2.45 ± ± ± 0.07 R fiss ( 237 Np) / R fiss ( 238 U) E max (MeV) GNASH Experiment 2.71 ± ± ± 0.11 Workshop on Activation Data EAF2007, October 2006, Prague 15

16 Extension to higher energies Recent evaluations ( 2005): 235,238 U, 237 Np, 239,240 Pu, 241 Am Collaboration with LANL GNASH code E γ 20 MeV Adopted in ENDF/B-VII.b2 (April 25 th, 2006) Photonuclear Physics in Radiation Transport III: Actinide Cross Sections & Spectra M-L. Giacri-Mauborgne, M.B. Chadwick, D. Ridikas, P.G. Young, W.B. Wilson, Nuclear Science and Engineering 153 (2006) In the coming years: New evaluations for higher energies TALYS code E γ 130 MeV Contribution to the JEFF library ( 235 U, 232 Th, 239 Pu, ) Workshop on Activation Data EAF2007, October 2006, Prague 16

17 I. Raskinyte Evaluation of Cross Sections: U, 232 Th Photoabsorption Cross Section: σ abs ( E γ ) = σgdr (E γ ) + σqd(e γ ) E γ 30 MeV : σ GDR ( E γ ) = σ E Γ 2 2 i γ i i = 1, 2 ( E γ E i ) + E γ Γ 2 i E i, Γ i, σ i : GDR parameters E γ 30 MeV : σ QD NZ ( E γ ) = L σ d A ( E γ ) f ( E γ ) σ d : d photodisintegration XS L : Levinger parameter f(e γ ) : Pauli blocking function photoabsorption GDR parameters by Caldwell, et al., PRC 21 (1980) 1215 γ-absorption GDR parameters fitted on Varlamov data [INDC(CCP)-440] Workshop on Activation Data EAF2007, October 2006, Prague 17

18 I. Raskinyte Evaluation of Cross Sections: U, 232 Th Compound Nucleus Decay Level density models Gilbert-Cameron composite formula with Ignatyuk level density parameter ρ(e x ) = ρ T (E x ρ F (E x E E M M ) ) = 1 E x E 0 = exp T T π exp( 2 au ) 1/ 4 5 / 12 2πσa U 4 U = E x Δ U a = a~ 1 exp( γ 1 + δ W U ~ 2 a, δ W, γ, Δ, σ ) from systematic The constant-temperature law (ρ T ) is fitted on discrete levels The matching energy (E M ) is adjusted to ensure continuity Neutron OMP (in the exit channel) Transmission coefficients calculated with a global coupled-channel OMP by Soukhovitskii, et al. [J. Phys. G 30 (2004) 905] Workshop on Activation Data EAF2007, October 2006, Prague 18

19 I. Raskinyte Evaluation of Cross Sections: U, 232 Th The fission channel: double-humped parabolic model Effective transmission coefficient for a double-humped barrier: T1T 2 Tf = T + T 1 2 γ+ 232 Th (γ,f) For a transition state at energy ε above a parabolic barrier, ε 1 Ti = 1,2 (E x ) = E ε x Bi 1+ exp 2π hωi Barrier heights (B i ) & curvatures (hω i ) are fitted onto experimental data 0 and 1 transition states above the 2 nd barrier ( 232 Th) Workshop on Activation Data EAF2007, October 2006, Prague 19

20 I. Raskinyte Evaluation of Cross Sections: U, 232 Th Additional fine tuning of the calculations Uranium + Pre-equilibrium normalization Thorium Th, 230 Th GDR parameters, Th γ-ray strength function norm. Workshop on Activation Data EAF2007, October 2006, Prague 20

21 I. Raskinyte Evaluation of Cross Sections: U, 232 Th Calculations up to 130 MeV for 235 U Workshop on Activation Data EAF2007, October 2006, Prague 21

22 A. Vanlauwe FY ABLA Calculations for U, 238 U 235 U 15 MeV 25 MeV Data files require information on FFs YIELD (%) DATA ABLA YIELD (%) Both mass & charge distributions are reproduced 238 U 15 MeV 25 MeV Fragment Mass (A) Fragment Mass (A) No/little experimental isotopic distributions available YIELD (%) DATA ABLA YIELD (%) Fragment Mass (A) Fragment Mass (A) Workshop on Activation Data EAF2007, October 2006, Prague 22

23 A. Vanlauwe FY ABLA Calculations for Pu, 237 Np YIELD (%) Nucleus potential (MeV) 239 Pu Data ABLA* Data ABLA* 237 Np ABLA YIELD (%) Fragment Mass (A) Workshop on Activation Data EAF2007, October 2006, Prague 23

24 From FY to DN ABLA Calculations 1. ABLA independent Y(A,Z) 2. CINDER 90 Y C (A,Z) 3. Nuclear data T 1/2, P DN 235 U (E e =15 MeV) 6 6 c DN λ t DN = i i = ν d i i= 1 i= 1 Y t Y P e Fe i i () DATA versus ABLA 238 U (E e =15 MeV) λ t GROUP 1 Yield Data 0.052±0.010 Calc T 1/2 (s) Data 54.7±2.5 Calc Yield Data 0.061±0.010 Calc T 1/2 (s) Data Calc. 56.2± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± TOTAL 0.962± ± Total yield: Decay constants: Group yields: Workshop on Activation Data EAF2007, October 2006, Prague 24

25 Exp DN from 238 U(γ,f) Pb γ 3 He Experiments performed in collaboration with DPTA/SPN CEA/DIF, Bruyères-le-Châtel 238 U electrons Ta Al Pb γ 3 He 238 U ELSA electron accelerator Energy MeV 140 µs pulses at 10 Hz average intensity up to 1 µa perfect energy resolution and beam focalization Workshop on Activation Data EAF2007, October 2006, Prague 25

26 Exp DN Total Yield from 238 U(γ,f) Data with 0.14 ms, 10 s, & 300 s irradiations DN time spectra: Electron energy 15 MeV 400 g of 238 U ~20 DN/s at t=0 ν d = ±6% (this work) ν d = ±13% (Nikotin) ν = d N N ( t= 0) s He3 ε Ω fiss He 3 He 3 Parameters from Nikotin 65 i Y () t = ν Fe λ t DN d i i= 1 6 Workshop on Activation Data EAF2007, October 2006, Prague 26

27 Exp DN Total Yield from 238 U(γ,f) Workshop on Activation Data EAF2007, October 2006, Prague 27

28 Exp DN Fractions from 238 U(γ,f) Kull s data are confirmed Disagreement with Nikotin s data 2 nd chance fission of little importance at 15 MeV end point Bremsthralung? Workshop on Activation Data EAF2007, October 2006, Prague 28

29 Summary and outlook For more than 500 isotopes, up to 25 MeV, calculations of - Cross Sections - Fission Yields (actinides) - Delayed Neutron Yields (actinides) April 2006: pre-release (to LANL) of PAF for CINDER 90 For 6 actinides: 235 U, 238 U, 237 Np, 239 Pu, 240 Pu & 241 Am - Accurate data evaluations up to 20 MeV Adopted in ENDF/B-VII (β version) On-going work Actinide evaluations up to 150 MeV - formatting of the data (ENDF) Contribution to the JEFF library ( 232 Th, 235 U, 239 Pu) Workshop on Activation Data EAF2007, October 2006, Prague 29

30 Latest publications Latest publications see I. Raskynite, et al. : Photonuclear Data Evaluation of Actinides, Conf. on Nuclear Reaction Mechanism, Varenna (Italie), June 2006 A. Vanlauwe, et al. : Photofission of 232 Th and 238 U with Bremsstrahlung Photons below 20 MeV: Measurements and Model Predictions of Delayed Neutron Yields and Spectra, Conf. on Nuclear Reaction Mechanism, Varenna (Italie), June 2006 M-L. Giacri-Mauborgne, et al. : Photonuclear Physics in Radiation Transport: Actinide Cross Sections and Spectra, NSE 153 (2006) 33 D. Ridikas, et al. : Status of the Photonuclear Activation File (PAF): reaction cross sections, fission fragments and delayed neutrons, IConf. on Nuclear Applications of Accelerator Technology (AccApp 2005), August 29 September 1, 2005, Venise (Italie), NIM A562 (2006) 710 Workshop on Activation Data EAF2007, October 2006, Prague 30