Oktavian Aluminium#

Here it is possible to find the analysis of Oktavian aluminum (oktavian_al) benchmark run with OFB.

CAD#

The following link opens an interactive 3D visualization of the CAD model and its relative mesh used in the benchmark:

Figure 1: Oktavian aluminum experiment CAD model and relative mesh.

Results#

Results are a set of energy spectra of neutron and photon leaking from the Oktavian aluminum sphere. Figures show energy spectra and C/E values are the ration between every computed value and the experimental value.

CAD-CSG comparison#

Comparison of Experimental, MCNP-CSG, OpenMC-CSG and OpenMC-CAD (from OFB) results for neutron and photon leakage spectra.

Figure 2: Neutron leakage spectrum comparison between CAD and CSG geometries.

Figure 3: Photon leakage spectrum comparison between CAD and CSG geometries.

Nuclear Data on CAD analysis#

Comparison of ENDF\B-8.0, ENDF\B-8.1, FENDL-3.2b and JEFF-3.3 nuclear data libraries results run with OFB (OpenMC-CAD model) [BCC+18] [NCP+25] [SAB+24] [PCdSJ+20].

Figure 4: Neutron leakage spectrum for different nuclear data libraries using CAD geometry.

Figure 5: Photon leakage spectrum for different nuclear data libraries using CAD geometry.

Uncertainty Quantification analysis#

Total Monte Carlo Uncertainty Quantification (TMC-UQ) results obtained performing 500 perturbations of Al27 cross sections in ENDF\B-8.0 and run the OpenMC CAD model. The center panels and right panels of the two figfures give an insight of statistics at the ~14 MeV energy group for neutrons and ~7.5 MeV energy group for photons.

Figure 6: Neutron leakage spectrum with TMC-UQ results.

Figure 7: Photon leakage spectrum with with TMC-UQ results.

References#

[BCC+18]

David A Brown, Mark Benjamin Chadwick, R Capote, AC Kahler, A Trkov, MW Herman, AA Sonzogni, Y Danon, AD Carlson, M Dunn, and others. Endf/b-viii. 0: the 8th major release of the nuclear reaction data library with cielo-project cross sections, new standards and thermal scattering data. Nuclear Data Sheets, 148:1–142, 2018.

[KYT98]

Itsuro KIMURA, Junji YAMAMOTO, and Akito TAKAHASHI. Benchmark validation by means of pulsed sphere experiment at oktavian. In JAERI-Conf, 174. 1998.

[KOK+23]

Chikara Konno, Masayuki Ohta, Saerom Kwon, Seiki Ohnishi, Naoki Yamano, and Satoshi Sato. Jendl-5 benchmark test for shielding applications. Journal of Nuclear Science and Technology, 60(9):1046–1069, 2023.

[MYI+94]

Fujio Maekawa, Junji Yamamoto, Chihiro Ichihara, Kotaro Ueki, Yujiro Ikeda, and others. Collection of experimental data for fusion neutronics benchmark. Technical Report, Japan Atomic Energy Research Inst., Tokyo (Japan), 1994.

[NCP+25]

GPA Nobre, R Capote, MT Pigni, A Trkov, CM Mattoon, D Neudecker, DA Brown, MB Chadwick, AC Kahler, NA Kleedtke, and others. Endf/b-viii. 1: updated nuclear reaction data library for science and applications. arXiv preprint arXiv:2511.03564, 2025.

[PCdSJ+20]

Arjan JM Plompen, O Cabellos, Cyrille de Saint Jean, Michael Fleming, A Algora, Maurizio Angelone, P Archier, E Bauge, O Bersillon, A Blokhin, and others. The joint evaluated fission and fusion nuclear data library, jeff-3.3. The European Physical Journal A, 56(7):181, 2020.

[SAB+24]

G Schnabel, DL Aldama, T Bohm, U Fischer, S Kunieda, A Trkov, C Konno, R Capote, AJ Koning, Simona Breidokaite, and others. Fendl: a library for fusion research and applications. Nuclear Data Sheets, 193:1–78, 2024.

Oktavian Aluminium