Los Alamos National Laboratory
Profile Pages
Allan Benton Wollaber
Email
Phone (505) 6656837
Expertise
Diverse background in computational physics relevant to systems in which the interaction of neutralparticle radiation with matter is a significant phenomenon (e.g. nuclear reactors, radiative heat transfer, etc.). Interested in the development, extension, and analysis of highly scalable algorithms for the simulation of neutralparticle transport.
Education

LANL Positions

Computational Physicst (2010present)
Professional Societies

American Nuclear Society
Tau Beta Pi
Awards

 Principal Investigator for LDRD, Deterministically Enhanced Monte Carlo for Radiative Transfer, (20122014)
 ADX LAAP Award (2013)
 Neutronics code selected as finalist for Gordon Bell Supercomputing award (2009)
Publications

[1] T. S. Haut, R. B. Lowrie, H. Park, R. M. Rauenzahn, and A. B. Wollaber, “A linear stability analysis of the multigroup high order, low order (HOLO) method,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Nashville, TN), American Nuclear Society, April 19–23 2015.
[2] H. Park, A. B. Wollaber, R. M. Rauenzahn, and D. A. Knoll, “Efficient, threetemperature, thermal radiative transfer solution via a highorder, loworder method,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Nashville, TN), American Nuclear Society, April 19–23 2015.
[3] A. M. Holgado, R. T. Holladay, A. B. Wollaber, M. A. Cleveland, T. J. Urbatsch, and R. G. McClarren, “Kernel density estimation for grey Implicit Monte Carlo radiation transport,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Nashville, TN), American Nuclear Society, April 19–23 2015.
[4] M. A. Cleveland, A. B. Wollaber, R. B. Lowrie, K. G. Thompson, and G. R. Rockefeller, “Momentum deposition in curvilinear coordinates,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Nashville, TN), American Nuclear Society, April 19–23 2015.
[5] A. B. Wollaber, H. Park, R. B. Lowrie, R. M. Rauenzahn, and M. A. Cleveland, “Radiation hydro dynamics with a highorder, loworder method,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Nashville, TN), American Nuclear Society, April 19–23 2015.
[6] J. D. Densmore, H. Park, A. B. Wollaber, R. M. Rauenzahn, and D. A. Knoll, “Monte Carlo simulation methods in momentbased scalebridging algorithms for thermal radiativetransfer problems,” Journal of Computational Physics, vol. 284, pp. 40–58, March 2015.
[7] H. Park, D. A. Knoll, R. M. Rauenzahn, A. B. Wollaber, and R. B. Lowrie, “Momentbased accel eration of Monte Carlo solution for multifrequency thermal radiative transfer problems,” Journal of Computational and Theoretical Transport, vol. 43, Oct 2014.
[8] R. T. Wollaeger, T. J. Urbatsch, A. B. Wollaber, and J. D. Densmore, “Analysis of source tilting in Implicit Monte Carlo calculations,” Tech. Rep. LAUR1426400, Los Alamos National Laboratory, August 2014.
[9] R. B. Lowrie and A. B. Wollaber, “Simple materialmotion corrections for thermal radiative transport,” Transport Theory and Statistical Physics, vol. 43, pp. 1–14, 2014.
[10] A. B. Wollaber, “A linear stability analysis of a threetemperature operatorsplit system for two temperature radiation packages,” in Trans. Am. Nucl. Soc., vol. 109, (Washington D.C.), pp. 763–765, American Nuclear Society, November 1014 2013.
[11] H. Park, D. A. Knoll, R. M. Rauenzahn, A. B. Wollaber, and R. Lowrie, “Momentbased accelera tion of Monte Carlo solution for multifrequency thermal radiative transfer problems,” in International Conference on Transport Theory (ICTT23), (Santa Fe, NM), September 1520 2013.
[12] R. B. Lowrie and A. B. Wollaber, “Simple materialmotion corrections for thermal radiative transport,” in International Conference on Transport Theory (ICTT23), (Santa Fe, NM), September 1520 2013.
[13] A. B. Wollaber and J. S. Warsa, “A new, coupled transportdiffusion method for radiative transfer calculations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Com putation, (Sun Valley, ID), American Nuclear Society, May 5–9 2013.
[14] H. Park, J. D. Densmore, A. B. Wollaber, D. A. Knoll, and R. M. Rauenzahn, “Monte Carlo solution methods in a momentbased scalebridging algorithm for thermal radiative transfer problems: Com parison with Fleck and Cummings,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Sun Valley, ID), American Nuclear Society, May 5–9 2013.
[15] A. B. Wollaber, E. W. Larsen, and J. D. Densmore, “A discrete maximum principle for the Implicit Monte Carlo equations,” Nuclear Science and Engineering, vol. 173, pp. 259–275, March 2013.
[16] E. E. Lewis, Y. Li, M. A. Smith, W. S. Yang, and A. B. Wollaber, “Preconditioned Krylov solution of response matrix equations,” Nuclear Science and Engineering, vol. 173, pp. 222–232, March 2013.
[17] H. Park, D. A. Knoll, R. M. Rauenzahn, C. K. Newman, J. D. Densmore, and A. B. Wollaber, “Physics based preconditioning and accurate time integration for a momentbased scalebridging algorithm,” SIAM Journal on Scientific Computing, vol. 41, 2013.
[18] R. M. Rauenzahn, D. A. Knoll, H. Park, A. B. Wollaber, and J. D. Densmore, “Progress in acceleration of radiation transport methods by loworder methods (U),” in Proceedings of the 17th Nuclear Explosives Code Developers Conference, (Livermore, CA), October 22–26 2012.
[19] H. Park, D. A. Knoll, R. M. Rauenzahn, A. B. Wollaber, and J. D. Densmore, “A consistent, moment based, multiscale solution approach for thermal radiative transfer problems,” Transport Theory and Statistical Physics, vol. 41, pp. 284–303, September 2012.
[20] P. W. Talbot, A. B. Wollaber, and T. S. Palmer, “Implementing a discrete maximum principle for the IMC equations,” in American Nuclear Society (ANS) Annual Meeting, Trans. Am. Nucl. Soc., 2012.
[21] A. B. Wollaber, “Necessary and sufficient conditions for an Implicit Monte Carlo discrete maximum principle,” in International Conference on Transport Theory (ICTT22), (Portland, OR), September 1216 2011.
[22] A. B. Wollaber, “A synthesized Fleck factor for the Implicit Monte Carlo equations,” in American Nuclear Society (ANS) Annual Meeting, Trans. Am. Nucl. Soc., vol. 104, (Hollywood, FL), June 26–30 2011.
[23] E. Lewis, M. A. Smith, W. S. Yang, and A. Wollaber, “Preconditioned Krylov and GaussSeidel solutions of response matrix equations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Rio De Janeiro, Brazil), American Nuclear Society, May 8–12 2011.
[24] A. B. Wollaber, E. W. Larsen, and J. D. Densmore, “Towards a frequencydependent discrete maximum principle for the Implicit Monte Carlo equations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Rio De Janeiro, Brazil), American Nuclear Society, May 8–12 2011.
[25] A. B. Wollaber and E. W. Larsen, “A linear stability analysis for nonlinear, grey, thermal radiative transfer problems,” Journal of Computational Physics, vol. 230, pp. 1528–1546, February 2011.
[26] A. B. Wollaber and E. W. Larsen, “On the stability of the AhrensLarsen or SMC equations for thermal radiative transfer,” in Trans. Am. Nucl. Soc., vol. 103, (Las Vegas, Nevada), pp. 315–317, American Nuclear Society, November 711 2010.
[27] W. S. Yang, M. A. Smith, C. H. Lee, A. B. Wollaber, D. Kaushik, and A. S. Mohamed, “Neutronics modeling and simulation of SHARP for fast reactor analysis,” Nuclear Engineering and Technology, vol. 42, pp. 520–545, October 2010.
[28] T. Urbatsch, J. Densmore, G. Rockefeller, K. Thompson, M. Cleveland, N. Chrien, A. Wollaber, M. Buk sas, T. Kelley, P. Henning, A. Hungerford, T. M. Evans, S. Mosher, S. R. Johnson, and R. McClarren, “Users’ guide: Milagro version 5, an Implicit Monte Carlo code for thermal radiative transfer,” unclas sified report, Los Alamos National Laboratory, July 22, 2010. Unpublished. Located in repository at milagro/doc/users manual/users guide milagro5 0 0.tex.
[29] E. Lewis, A. Wollaber, A. MarinLafleche, M. A. Smith, and W. S. Yang, “Comparison of Krylov and pmultigrid solutions of orthogonal response matrix equations.,” in American Nuclear Society (ANS) Annual Meeting, Trans. Am. Nucl. Soc., vol. 102, (San Diego, CA), June 1317 2010.
[30] E. Lewis, A. Wollaber, A. MarinLafleche, M. Smith, and W. Yang, “Response matrix acceleration methods based on orthogonalization and domain decomposition,” in American Nuclear Society (ANS) Annual Meeting, Trans. Am. Nucl. Soc., vol. 102, June 1317 2010.
[31] M. A. Smith, D. Kaushik, A. B. Wollaber, W. S. Yang, and B. Smith, “New neutronics analysis tool development at Argonne National Laboratory,” in Proc. of Int. Conf. on Fast Reactors and Related Fuel Cycles (FR09), (Kyoto, Japan), December 711 2009.
[32] A. B. Wollaber and E. W. Larsen, “A hybrid Monte Carlodeterministic approach to improve the accuracy and efficiency of Monte Carlo calculations for thermal radiative transfer,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, vol. 2, (Saratoga Springs, New York), pp. 1246–1263, American Nuclear Society, 2009.
[33] A. B. Wollaber and E. W. Larsen, “A linear stability analysis for nonlinear, 1D, gray Implicit Monte Carlo calculations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, (Saratoga Springs, New York), American Nuclear Society, 2009.
[34] A.B.WollaberandE.W.Larsen,“AtimedependentFleckfactortoenhancetheaccuracyoftheImplicit Monte Carlo equations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, vol. 2, (Saratoga Springs, New York), pp. 1618–1634, American Nuclear Society, 2009.
[35] D. Kaushik, M. Smith, A. Wollaber, B. Smith, A. Siegel, and W. S. Yang, “Enabling highfidelity neutron transport simulations on petascale architectures,” in Proceedings of the Conference on High Performance Computing Networking, Storage and Analysis, SC ’09, (1515 Broadway, 17th Floor New York, NY 100365701, United States), Association for Computing Machinery, 2009.
[36] C. Rabiti, G. Palmiotti, W. Yang, M. Smith, D. Kaushik, and A. Wollaber, “Quasi linear representation of the isotropic scattering source for the method of characteristics,” in American Nuclear Society  International Conference on Mathematics, Computational Methods and Reactor Physics 2009, M and C 2009, vol. 1, (555 North Kensington Avenue La Grange Park, IL 60526, United States), pp. 461–473, American Nuclear Society, 2009.
[37] M. A. Smith, D. Kaushik, A. Wollaber, W. S. Yang, B. Smith, C. Rabiti, and G. Palmiotti, “Recent research progress on UNIC at Argonne National Laboratory,” in American Nuclear Society International Conference on Mathematics, Computational Methods and Reactor Physics 2009, M and C 2009, vol. 1, (555 North Kensington Avenue La Grange Park, IL 60526, United States), pp. 80–97, American Nuclear Society, 2009.
[38] E. W. Larsen and A. B. Wollaber, “A quantitative theory of angular truncation errors in 3D Sn calculations,” Nuclear Science and Engineering, vol. 160, pp. 267–283, 2008.
[39] A. B. Wollaber, Advanced Monte Carlo Methods for Thermal Radiation Transport. PhD thesis, The University of Michigan, 2008.
[40] E. W. Larsen and A. B. Wollaber, “A quantitative theory of angular truncation errors in 3D dis crete ordinates calculations,” in Proc. ANS Topical Meeting, Joint International Topical Meeting on Mathematics & Computation and Supercomputing in Nuclear Applications (M&C + SNA 2007), On CDROM, American Nuclear Society, LaGrange Park, IL, April 1519 2007.
[41] A. B. Wollaber and E. W. Larsen, “A hybrid Monte Carlo deterministic method for global, time dependent transport calculations,” in Trans. Am. Nucl. Soc., vol. 95, (Albuquerque, New Mexico), pp. 865–7, American Nuclear Society, November 1216 2006.
[42] A. B. Wollaber, “A hybrid Monte Carlodeterministic method for efficient global transport solutions,” Tech. Rep. CCS4:0550(U), Los Alamos National Laboratory, May 12, 2006.
[43] T. L. Becker, A. B. Wollaber, and E. W. Larsen, “A hybrid Monte Carlo deterministic method for global particle transport calculations,” Nuclear Science and Engineering, vol. 155, pp. 155–167, 2006.
[44] A. B. Wollaber and E. W. Larsen, “A hybrid Monte Carlo deterministic method for global deep pen etration particle transport calculations,” in Proc. ANS Topical Meeting, International Topical Meeting on Mathematics and Computation, Supercomputing, Reactor Physics, and Nuclear and Biological Appli cations, (Avignon, France), September 1215 2005. On CDROM, American Nuclear Society, LaGrange Park, IL (2005).
[45] A. B. Wollaber, R. E. Pevey, and J. C. Gehin, “Analysis of burnable absorber options for IRIS core de sign,” in Advances in Nuclear Fuel Management III (ANFM 2003), (Hilton Head Island, South Carolina, USA), October 58 2003. On CDROM, American Nuclear Society, LaGrange Park, IL (2003).
[46] A. B. Wollaber, “Burnable poison design for the international reactor, innovative and secure (IRIS),” Master’s thesis, University of Tennessee, Knoxville, 2003.