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MACS and Astrophysical Reaction Rates from ENDF/B-VII.0, JEFF-3.1,

MACS and Astrophysical Reaction Rates from ENDF/B-VII.0, JEFF-3.1, JENDL-3.3, ENDF/B-VI.8 Evaluated Neutron Libraries B. Pritychenko * , A. Sonzogni, S. Mughabghab National Nuclear Data Center Brookhaven National Laboratory * Email: pritychenko@bnl.gov. Brookhaven Science Associates.

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MACS and Astrophysical Reaction Rates from ENDF/B-VII.0, JEFF-3.1,

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  1. MACS and Astrophysical Reaction Rates from ENDF/B-VII.0, JEFF-3.1, JENDL-3.3, ENDF/B-VI.8 Evaluated Neutron Libraries B. Pritychenko*,A. Sonzogni, S. Mughabghab National Nuclear Data Center Brookhaven National Laboratory *Email: pritychenko@bnl.gov Brookhaven Science Associates

  2. Nuclear Data activities started at BNL in 1951 with neutron compilations BNL-325 & Evaluated Nuclear Data File ENDF: core nuclear reaction database containing evaluated (recommended) data from the ENDF/B-VII.0 library (also JEFF, JENDL, BROND, CENDL and ENDF/B-VI.8). It uses ENDF-6 format, covering all nuclides of practical relevance (393 in total) for neutrons from 10-5 eV up to 20 MeV ENDF/B-VII.0 library was released on December 15, 2006 Evaluated Neutron Libraries

  3. 393 Neutron Evaluations in ENDF/B-VII.0 vs. 337 in JENDL-3.3 released in 2002 251 out of 286 nuclides (87.7%) from solar nuclide abundances paper by E. Anders & N. Grevesse, Geochim. Cosmochin. Acta 53 (1989) 197 390 (n,g) cross sections, no cross sections for 3H, 4He, 7Be Good for Maxwellian-averaged cross sections (s-process nuclei), astrophysical reaction rates ENDF/B-VII.0 Astrophysics Features

  4. ENDF data in eV – MeV regions are utilized by nuclear industry, fussion, national security applications keV region data for nuclear astrophysics Calculate 4 major neutron libraries under the same conditions Connection between ENDF & astrophysics Sigma: New ENDF Web interface Project Motivation

  5. MACS & Reaction Rates I Nuclear astrophysics s-process calculations require Maxwellian average neutron capture cross sections. Maxwellian cross section in nuclear astrophysics region are not more than 10% off from (n,g) cross sections

  6. Nakagawa et al., ADNDT 91 (2005) 77 Maxwellian-averaged cross section, [b] Astrophysical reaction rate, [cm3/s] MACS & Reaction Rates II

  7. Pointwise* ENDF data at 300K in Sigma DB (0K pointwise is in progress) AME2003 in bb-decay database Java 1.5 Simpson summation of pointwise data splitted into 2 slices, slice width < 10 keV for 26 neutron energy values: kT = 0.001 - 1 MeV Evaluated neutron data for all major libraries: ENDF/B-VII.0, JEFF-3.1, JENDL-3.3, ENDF/B- VI.8 were processed on Windows desktop in 4 - 5 h Java Implementation *It refers to conversion of resonance parameters into cross sections and to Doppler broadening them by taking into account neutron velocities at room temperature. Applies only to the neutron sublibrary in the resonance region.

  8. Lower & Upper Riemann (Rectangular), Trapezoidal, Midpoint, Recursive (Trapezoidal Power Of Two, Romberg, Simpson ) Simpson integration is prefferable Sigma pointwise libraries were linearized within 0.1%: sm = (s1+s2)/2 Numeric Integration

  9. Java numerical integration performs better than INTER ENDF utility code Simple trapezoidal MACS for JENDL-3.3 are within 2-5% from T. Nakagawa et al., ADNDT 91 (2005) 77 calculations based Simpson numerical integration + division of each slice into 2 + slice width < 10 keV agrees with Nakagawa et al. within 1% Hybrid (analytical + numerical) integration Bao et al. Maxwellian Cross Sections

  10. MACS comparison for 151Sm(n,g) • U. Abbondanno et al., PRL 93,161103 (2004) • K. Wisshak et al., PRC 73, 015802 (2006) • Simpson MACS (mb):

  11. Reaction rates for four major libraries have been calculated Neutron cross sections (30 keV) x Solar abundances (relative to Si = 106) sN ratio: JENDL-3.3: 122Te:123Te:124Te => 1:0.94:1.03 ENDF/B-VII.0: 122Te:123Te:124Te =>1:1.18:0.9 Covariances => Uncertainties Reaction Rates

  12. (n,g) Maxwellian cross sections and reaction rates have been calculated for four major libraries: ENDF/B-VII.0, JEFF-3.1, JENDL-3.3, ENDF/B-VI.8 Results were compared with: Calculations T. Nakagawa et al. ADNDT 91 (2005) 77 Bao et al. ENDF utility code INTER Neutron cross sections x Solar system abundances (n,p), (n,a), (n,f), (n,2n), (n,t+2a) reactions will follow Results will be loaded into Sigma database (Sigma Demonstration for Trento meeting) Future covariances will produce errors for MACS/Reaction Rates Conclusion & Outlook

  13. MACS comparison for 19F(n,g) • E. Uberseder et al., Phys. Rev. C75,035801 (2007), 44% lower than previous result • Simpson MACS (mb) for LA+CNDC+ORNL:

  14. Dear Boris, Thank you for your e-mail. Concerning nuclear masses, we used values given in head records of JENDL-3.3. I think small discrepancies between our results and yours might be caused by integration methods. In our calculation for adjacent two cross-section data points, a table of Sig(E)*E*exp(-E/kT) was created at fine energy mesh by using the dividing method originally used in RESEND code. Then integration was made by subroutine ECSI taken from ENDF/B utility codes. Best regards, Tsuneo Email from Nakagawa

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