Monte Carlo Code Development – MCNPX-PoliMi and MPPost Codes

Research Focus Areas: 1 & 4

Ph.D. Students: M.J. Marcath (Graduated) & J. Arthur (Graduated)

Collaborators: DTRA


Monte Carlo codes are the state of the art for simulating complex scenarios used to design measurement systems for a variety of applications including nuclear nonproliferation and safeguards. Many scenarios in these applications include challenging simulation geometries such as large source-to-detector distances and/or shielding material around the source. Furthermore, many safeguards-related systems rely on correlated detection of particles from nuclear fission, which is particularly challenging for traditional Monte Carlo codes that rely on average distributions to simulate physical quantities.

Top left: 252 CF time of flight with BC501 graph
Top middle: Feynman Y for 252 CF with poly shield graph
Bottom left: meter attached to machine
Bottom middle: Cf pulse height distribution with a liquid scintillator graph
Bottom right: Multiplicity measurement of 252 Cf graph

The MCNPX-PoliMi code was originally developed to simulate correlated-particle scenarios. Other Monte Carlo codes, such as MCNP and Geant4, utilize average physics treatments and are therefore not accurate for a single interaction. MCNPX-PoliMi contains several modifications to address this issue, resulting in a code capable of accurately modeling single-event physics, and the full statistics of neutrons and photons from fission and other interactions. In particular, the code has been used to design experiments to measure neutron multiplicity, time-of-flight, and cross-correlation distributions. We are continuing to work, in collaboration with the Polytechnic of Milan, Italy, to improve and enhance the capabilities in MCNPX-PoliMi such as detector response simulation, fission physics simulation, and variance reduction techniques.


Related Journal Articles:

  1. M.J. Marcath, S. D. Clarke, B. M. Wieger, E. Padovani, E. W. Larsen, S. A. Pozzi, “An Implicit Correlation Method for Cross-Correlation Sampling, with MCNPX-PoliMi Validation,” Nuclear Science and Engineering 181 (2015).
  2. S.D. Clarke, E. C. Miller, M. Flaska, S. A. Pozzi, R. B. Oberer, and L. G. Chiang, “Verification and Validation of MCNPX-PoliMi for Simulation of Neutron Multiplicity Measurements.” Nuclear Instruments and Methods in Physics Research Section A 700 (2013): 135 – 139.
  3. S.F. Naeem, S. D. Clarke, and S. A. Pozzi, “Validation of Geant4 and MCNPX-PoliMi Simulations of Fast Neutron Detection with the EJ-309 Liquid Scintillator,” Nuclear Instruments and Methods in Physics Research Section A 714 (2013): 98 – 104.
  4. S.A. Pozzi, S.D. Clarke, W.J. Walsh, E.C. Miller, J.L. Dolan, M. Flaska, B.M. Wieger, A. Enqvist, E. Padovani, J.K. Mattingly, D.L. Chichester, P. Peerani, MCNPX-PoliMi for nuclear nonproliferation applications, Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 694 (2012) 119–125.
  5. E.C. Miller, S. D. Clarke, M. Flaska, S. A. Pozzi, and E. Padovani, “MCNPX-PoliMi Post-Processing Algorithm for Detector Response Simulation,” Journal of Nuclear Materials Management vol. XL, no. 2 (2012): 34 – 41.
  6. S.A. Pozzi, E. Padovani, M. Marseguerra, MCNP-PoliMi: A Monte-Carlo code for correlation measurements, Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 513 (2003) 550–558.

Related Conference Proceedings:

  1. S.D. Clarke, M. J. Marcath, M. L. Ruch, J. L. Dolan, M. Flaska, E. W. Larsen, E. Padovani, P. Peerani, and S. A. Pozzi, “Advances in the MCNPX-PoliMi Code for Nuclear Safeguards Applications,” Proceedings of the Institute of Nuclear Materials Management 55thAnnual Meeting, Atlanta, GA, USA. July 20 – 24, 2014, available online.
  2. S.A. Pozzi, A. Enqvist, B. Wieger, S. D. Clarke, M. Flaska, M. Marcath, E. W. Larsen, R. C. Haight, N. Puppato, and E. Padovani (2013). “Fission Models in MCNPX-PoliMi,” Proceedings of the Institute of Nuclear Materials Management 54thAnnual Meeting, Palm Desert, CA, USA, July 14 – 18, 2013, available online.
  3. S.D. Clarke, M. L. Ruch, M. M. Marcath, S. A. Pozzi, and E. W. Larsen, “Enhanced Variance Reduction Capabilities in the MCNPX-PoliMi Code,” Proceedings of the Institute of Nuclear Materials Management 54thAnnual Meeting, Palm Desert, CA, USA, July 14 – 18, 2013, available online.
  4. M.L. Ruch, S. D. Clarke, and S. A. Pozzi, “Improvements in the MCNPX-PoliMi Post-processing Code for Determining Detector Response,” Proceedings of the Institute of Nuclear Materials Management 54thAnnual Meeting, Palm Desert, CA, USA, July 14 – 18, 2013, available online.
  5. M.J. Marcath, E. W. Larsen. S. D. Clarke, and S.A. Pozzi, “A New “Implicit Correlation” Method for Cross-Correlation Sampling in MCNPX-PoliMi,” Transactions of the 2013 International Conference on Mathematics and Computational Methods Applied to Nuclear Science & Engineering (M&C 2013), Sun Valley, Idaho, USA, May 5 – 9, 2013.
  6. S.D. Clarke, S.A. Pozzi, and E. Padovani, “Photonuclear Physics Modeling in the MCNPX-PoliMi Code.” 2012 IEEE Nuclear Science Symposium Conference Record, Anaheim, CA USA, Oct. 27 – Nov. 3, 2012, on CD-ROM.
  7. S.A. Pozzi, S. D. Clarke, W. Walsh*, E. C. Miller, J. Dolan, M. Flaska, B. M. Wieger, A. Enqvist, E. Padovani, J. K. Mattingly, D. Chichester, and P. Peerani, “Validation of MCNPX-PoliMi Fission Models,” 2012 IEEE Nuclear Science Symposium Conference Record, Anaheim, CA USA, Oct. 27 – Nov. 3, 2012, on CD-ROM.
  8. S.F. Naeem, S. D. Clarke, and S. A. Pozzi, “Comparison of Geant4 and MCNPX-PoliMi Induced Fission Models,” 2012 IEEE Nuclear Science Symposium Conference Record, Anaheim, CA USA, Oct. 27 – Nov. 3, 2012, on CD-ROM.
  9. S.F. Naeem, S. D. Clarke, and S. A. Pozzi, “Comparison of Neutron Pulse Height Distributions from Organic Scintillators Calculated by Geant4 and MCNPX-PoliMi,” Proceedings of the Institute of Nuclear Materials Management 53rd Annual Meeting, Orlando, FL, USA, Jul. 15 – 19, 2012, on CD-ROM.
  10. S. Prasad, S. D. Clarke, S. A. Pozzi, and E. W. Larsen, “Time-Dependent Nonanalog MCNPX-PoliMi Scintillation Detector Response for Neutrons,” Proceedings of the Institute of Nuclear Materials Management 53rd Annual Meeting, Orlando, FL, USA, Jul. 15 – 19, 2012, on CD-ROM.
  11. S.A. Pozzi, S. D. Clarke, W. Walsh, E. Miller, J. Dolan, B. Weiger, M. Flaska, A. Enqvist, S. Naeem, J. Mattingly, N. Puppato, E. Padovani, and P. Peerani, “MCNPX-PoliMi for the Simulation of the Neutron and Gamma-ray Emissions from Nuclear Fission,” Proceedings of the Institute of Nuclear Materials Management 53rd Annual Meeting, Orlando, FL, USA, Jul. 15 – 19, 2012, on CD-ROM.
  12. S. Prasad, S. D. Clarke, S. A. Pozzi, and E. W. Larsen, “Organic Scintillation Detector Response Simulation Using Non-Analog MCNPX-PoliMi,” Transactions of the International Conference on Reactor Physics 2012 (PHYSOR 2012), Knoxville, TN, USA, Apr. 15 – 20, 2012, on CD-ROM.
  13. S.D. Clarke, M. Flaska, S. A. Pozzi, R. B. Oberer, and L. Chiang, “MCNPX-PoliMi Simulation of an Active Well Coincidence Counter Measurements of Uranium-Oxide Standards,” Proceedings of the Institute of Nuclear Materials Management 52nd Annual Meeting, Palm Desert CA, USA, Jul. 17 – 22, 2011, on CD-ROM.
  14. S.D. Clarke, M. Flaska, S. A. Pozzi, R. B. Oberer, and L. Chiang, “MCNP-PoliMi Analysis of Neutron-Source Penetrability in Uranium-Oxide Samples Measured with an Active Well Coincidence Counter,” 2010 IEEE Nuclear Science Symposium Conference Record, Knoxville, TN USA, Oct. 30 – Nov. 6, 2010, on CD-ROM.
  15. E.C. Miller, B. Dennis*, S. D. Clarke, S. A. Pozzi, and J. K. Mattingly, “Simulations of Neutron Multiplicity Measurements of a Weapons-Grade Plutonium Sphere with MCNP-PoliMi,” Proceedings of the Institute of Nuclear Materials Management 51st Annual Meeting, Baltimore, MD, USA, Jul. 11 – 15, 2010, on CD-ROM.
  16. E.C. Miller, S. D. Clarke, S. A. Pozzi, and J. K. Matingly, “Plutonium Sphere Multiplicity Simulations with MCNP-PoliMi,” 2009 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, Orlando, FL, USA, Oct. 25 – 31, 2009, on CD-ROM.