Dan Shumaker, a computational physicist at CASC, has been at LLNL since 1970. His research interests include simulation and visualization of physics problems using supercomputers. He is currently working on turbulent transport simulation in tokamak plasmas, using a 3-D parallel gyro-kinetic particle code. He is also applying streamline methods to the study of groundwater transport.

Dr. Shumaker earned his Ph.D. in Engineering Applied Science at the University of California, Davis in 1976. His honors and affiliations include a Hertz Fellowship in 1970-76, an Atomic Energy Commission Fellowship (offered), an RCA Scholarship, and a B.S. in Nuclear Engineering Science with high honors from University of Florida. He has been an adjunct lecturer at the University of California, Davis and a visiting physicist at the University of Flinders in Adelaide, Australia. He was a research assistant at R&D Associates, Santa Monica, CA; at the Reactor Division of the Oak Ridge National Laboratory, Tennessee; and at the Nuclear Engineering Department and the Chemical Engineering Department of the University of Florida.

1. Shumaker, D.E., "Probe Measurement in an Electrodeless RF Discharge," *High Honors paper*, Dept. of Nuclear Engineering, University of Florida, 1969.

2. Fagen, W.F., R.T. Schneider and D.E. Shumaker, "Radiation of Plasmoids in an Electrodeless R-F Discharge," *London Conference on Gas Discharges*, 192 (1970).

3. Shumaker, D.E. and I.B. Bernstein, "Improved Variational Method for Axisymmetric Plasma," *Phys. Fluids* **18**, 1487 (1975).

4. Shumaker, D.E., *Calculation of Transport Coefficients in an Axisymmetric Plasma*, Ph.D. thesis, University of California, Davis, 1976. Also available as Lawrence Livermore National Laboratory technical report UCRL-52218 (1977).

5. Post, D.E., R.J. Goldston, R.C. Grimm, R.J. Hawryluk, S.P. Hirshman, D. Hsieh, R.A. Hulse, D.L. Jassby, R.V. Jensen, A. Mckenney, D.M. Meade, D.R. Mikkelsen, J.M. Ogden, M. Okabayashi, P.H. Rutherford, J.A. Schmidt, F.G.P. Seidl, S. Suckewer, F. Tenney, A.A. Mirin, M.G. McCoy, J. Killeen, M.E. Rensink, D.E. Shumaker, and C.B. Taylor, "Computational Studies of Impurity Effects, Impurity Control, and Neutral Beam Injection In Large Tokamaks," in IAEA-CN-37-F-3 (IAEA, Vienna, Austria), *Seventh International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Innsbruck, Austria, 1978.

6. Mirin, A.A., M.G. McCoy, J. Killeen. M.E. Rensink, D.E. Shumaker, D.L. Jassby and D.E. Post, "Fokker-Planck/Transport Analyses of Fusion Plasmas in Contemporary Beam-Driven Tokamaks," *Joint Varenna-Grenoble International Symposium on Heating in Toroidal Plasmas*, **13** Grenoble, Switzerland, 1978.

7. Anderson, D.V., S.P. Auerbach, H.L. Berk, J.K. Boyd, T.A. Brengle, J.A. Byers, B.I. Cohen, W.C. Condit, J.C. Eddlerman, R.P. Freis, E.H.A. Granneman, J.H. Hammer, C.W. Hartman, J. Killeen, B. McNamara, W.A. Newcomb, L.D. Pearlstein, M.G. McCoy, D.S. Prono, J.M. Sayer, D.D. Schnack, D.E. Shumaker, J.W. Shearer, A.C. Smith, Jr., J. Taska, W.C. Turner, D.E. Driemeyer, G.H. Miley, E.C. Morse, E. McColl, and H. Weitzner, "Theory of Field-Reversed Mirrors and Field Reversed Plasma-Gun Experiments," in IAEA-CN-38/R-2, **I**, 469 (IAEA, Vienna, Austria), *8th International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Brussels, Belgium, 1980.

8. Shumaker, D.E., J.K. Boyd, S.P. Auerbach, and B. McNamara, "Numerical Simulation of Transport in a Field-Reversed Mirror Plasma," *J. Comput. Phys.* **45** (1982).

9. Harned, D.S., D.W. Hewett, C.G. Lilliequist, R.W. Moses, D.D. Schnack, J.L. Schwazmeier, A.G. Sgro, R.L. Spencer, D.V. Anderson, J. Killeen, A.A. Mirin, N.J. O'Neill, A.I. Shestakov, D.E. Shumaker, S.P. Auerbach, J.K. Boyd, T.A. Brengle, B.I. Cohen, J.H. Hammer, C.W. Hartman, W.C. Turner, A. Aydemir, D.C. Barnes, C. Bernard, W.M. Tang, C. Seyler, and J. Tataronis, "Compact Toroidal Plasmas: Simulation and Theory", in IAEA-CN-41/M-2-2, **II** (IAEA, Vienna, Austria), *9th International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Baltimore, MD, 1982.

10. Shumaker, D.E., "Numerical Calculation of Compact Torus Equilibria,"* J. Comput. Phys.* **53**, 456 (1984). [PDF]

11. Jarboe, T.R., Cris N. Barnes, I. Hening, H.N. Hoida, S.O. Knox, R.K. Linford, G.J. Marklin, D.A. Platts, A.G. Sgro, A.R. Sherwood, B.L. Wright, A.A. Mirin, and D.E. Shumaker, "Spheromak Studies on CTX," in IAEA **II**, 501 (IAEA, Vienna, Austria), *Tenth International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, London, U.K., September 12—19, 1984.

12. Siemon, R.E., W.T. Armstrong, R.E. Chrien, P.L. Klinger, R.K. Linford, K.F. McKenna, D.J. Rej, J.L. Schwarzmeier, A. Sgro, E.G. Sherwood, R.L. Spencer, M. Tuszewski, N.T. Gladd, D.S. Harned, D.E. Shumaker, and C.E. Seyler, "Theoretical Studies of Field-Reversed Configurations (FRCs) and Experimental Study of the FRC During Translation," in IAEA **II**, 551 (IAEA, Vienna, Austria), *Tenth International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, London, U.K., September 12—19, 1984.

13. Shumaker, D.E., "Numerical Calculation of Equilibrium for the Field-Reversed Configuration," *Fusion Tech*. **9**, 75 (1986).[PDF]

14. Barnes, D.C., W.T. Armstrong, E.J. Caramana, R.E. Chrien, W.H. Hugrass, H.R. Lewis, R.K. Linford, K.M. Ling, K.F. McKenna, D.J. Rej, J.L. Schwarzmeier, R.E. Siemon, M.M. Tuszewski, K.A. Werley, D.S. Harned, S. Okada, C.E. Seyler, D.E. Shumaker, H. Tuczek, G.C. Vlases, R. Ramen and J. Wright, "Theoretical and Experimental Studies of Field-Reversed Configuration," in IAEA-CN-47/D-V-9, **II**, 673 (IAEA, Vienna, Austria), *Eleventh International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Kyoto, Japan, November 13—20, 1986.

15. Shumaker, D.E., *Transport in Field-Reversed Configuration: Comparison of Simulation and Experiment*, Lawrence Livermore National Laboratory technical report UCRL-94433.

16. Shumaker, D.E., "EIV: Axisymmetric Plasma Equilibrium Code," *Comput. Phys. Commun.* **44**, 177 (1987). Also available as Lawrence Livermore National Laboratory technical report UCRL-94898 (1987).

17. Anderson, D.V., A.E. Koniges, and D.E. Shumaker, "CPDES2: A Preconditioned Conjugate Gradient Solver for Linear Asymmetric Matrix Equations Arising from Coupled Partial Differential Equations in Two Dimensions," *Comput. Phys. Commun. *

18. Anderson, D.V., A.E. Koniges, and D.E. Shumaker, "CPDES3: A Preconditioned Conjugate Gradient Solver for Linear Asymmetric Matrix Equations Arising from Coupled Partial Differential Equations in Three Dimensions," *Comput. Phys. Commun. *

19. Killeen, J., G.D. Kerbel, M.G. McCoy, A.A. Mirin, E.J. Horowitz, D.E. Shumaker, "Computer Models for Kinetic Equations of Magnetically Confined Plasmas," in *Proceeding of 1987 International Conference on Plasma Physics*, Kiev, USSR (1987). [PDF]

20. Shumaker, D.E. and E.J. Horowitz, "Development of QN3D, a 3-D Hybrid Particle Code," *NMFECC Buffer*, **11** No. 9, 3 (1987).

21. Shumaker, D.E. and E.J. Horowitz, "Applications of the QN3D Code to the FRC Tilt Mode," *NMFECC Buffer*, **12** No. 12, 20 (1987).

22. Shumaker, D.E., "Transport Simulation of a Field-Reversed Configuration Plasma," *Fusion Tech.*, **13**, 555 (1988).

23. Horowitz, H.R., D.E. Shumaker, and D.V. Anderson, "QN3D: A Three Dimensional Quasi-Neutral Hybrid Particle-in-Cell Code with Applications to the Tilt Mode Instability in Field Reversed Configuration," *J. Comput Phys*., **84**, 279 (1989).[PDF]

24. Lewis, H.R., D.C. Barens, R.C. Bishop, N.A. Krall, Z. Mikic, R.D. Milroy, A.A. Mirin, A.G. Sgro, D.E. Shumaker, J. L. Staudenmeier, and R.B. Webster, "The Till Mode, Turbulence and Transport in Field-Reversed Configuration," in IAEA-CN-50/C-5-15 (IAEA, Vienna, Austria), *Twelfth International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Nice, France, 1988.

25. Hartman, C.W., W.L. Barr, J.L. Eddleman, M. Gee, J.H Hammer, S.K. Ho, B.G. Logan, D.J. Meeker, A.A. Mirin, W.M. Nevins, L.J. Perkins, D.E. Shumaker, A. Leonard, P.B. Park, H. McLean, E. Morse, D.R. Solvin, "Acceleration of Compact Toroid Plasma Rings for Fusion Applications," in IAEA-CN-50/H-1-11, *Twelfth International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Nice, France, 1988. [PDF]

26. Shumaker, D.E., D.Q. Hwang and D. Flittner, "Davis Diverted Tokamak Design: Using the TSC Code to Avoid Axisymmetric Instabilities," *NMFECC Buffer*, **12** No. 9, 17 (1988).

27. Hwang, D., D.E. Shumaker, K. Mizuno, G. Dimonte, B.I. Cohen, D. Flittner and T. Hilyer, "The Davis Diverted Tokamak," in *Institutional Research and Development 1988*, p. 222. Also available as Lawrence Livermore National Laboratory technical report UCRL-53689-88 (1988).

28. Mirin, A.A., J.H. Hammer, W.M Nevins, W.A. Newcomb, and D.E. Shumaker, "Theoretical Studies of Compact Torus Injection for Fueling and Current Drive in Magnetic Fusion Devices," in *Institutional Research and Development 1989* (1989).

29. Houlberg, W.A., D.W. Ross, G. Bateman, S.C. Cowley, P.C. Eftimion, W.W. Pfeiffer, G.D. Porter, D.E. Shumaker, L.E. Sugiyama and J.W. Wiley, "Modeling Transport in Toroidal Plasma: Status and Issues," *Phys. Fluids B*, **2**, 2913 (1990).

30. Mirin, A.A. and D.E. Shumaker, "MHD Simulation of the Fueling for a Tokamak Fusion Reactor through the Injection of Compact Toroids," in *Energy Sciences Supercomputing 1990*. Also available as Lawrence Livermore National Laboratory technical report UCRL-53916, (1990).

31. Brown, M.R., P.M. Bellan, C.W. Hartman, J.L. Ebbleman, M. Gee, J.H. Hammer, B.G. Logan, R.W. Moir, H.S. McLean, A.A. Mirin, A.W. Molvik, W.M. Nevins, W.A. Newcomb and D.E. Shumaker, "Tokamak Current Drive & Fueling by Compact Torus Injection and Acceleration of Compact Toroids for Other Fusion Applications," in IAEA-CN-53/G-2-10,* 13th International Conference on Plasma Physics and Controlled Nuclear Fusion Research*, Washington, DC, 1990.

32. Shumaker, D.E., D.V. Anderson, and G.F. Simonson, *3D and 2D Simulation of an Expanding Plasma Using a Darwin Hybrid Particle Code,* Lawrence Livermore National Laboratory technical report UCRL-ID-109852 (1992).

33. Simonson, G.F., J.A. Byers, Gregory J. DiPeso, Dennis W. Hewett, and Dan E. Shumaker, *A Magnetically Contained Mach Three Expansion*, Lawrence Livermore National Laboratory technical report UCRL-ID-112735 (1993).

34. Mirin, A.A., D.E. Shumaker and M.G. McCoy, "High-Performance Global Climate Modeling," in *Laboratory Directed Research and Development FY 1992*, Lawrence Livermore National Laboratory technical report UCRL -53689-92 (1993).

35. Ambrosiano, J.J., J. Bolsted, A.J. Bourgeois, J.C. Brown, B. Chan, W.P. Dannevik, P.G. Eltgroth, B. Grant, C. Matarazzo, A.A. Mirin, D.E. Shumaker, and M.F. Weber, "High Performance Climate System Modeling Using a Domain and Decomposition Message Passing Approach," *Scalable High Performance Computing Conference*, Knoxville, TN, May 1994.

36. Kerbel, Gary D., Ron E. Waltz, Dan E Shumaker, Jose L. Milovich, Greg Hammet, Mike Beer, and Alan Verlo, "Scientific Visualization of Gyrofluid Tokamak Turbulence Simulation," *Visual Proceedings*, *SIGGRAPH*, **94**, 239 (1994).

37. Anderson, D. V., and D. E. Shumaker, "Hybrid Ordered Particle Simulation (HOPS) Code for Plasma Modeling on Vector-Serial, Vector-Parallel, and Massive Parallel Computers," Comput.* Phys. Commun.* **87**, 16, (1995). [PDF]

38. Kerbel, G.D., J.L. Milovich, D.E. Shumaker, R.E. Waltz, and A. Verlo, "Interactive Scientific Exploration of Tokamak Gyro-Landau Fluid Turbulence in a Visual Immersion Environment,"* AVS95* (1995).

39. Ashby, S.F., C. Baldwin W. Bosl, R. Falgout, R. Maxwell, J. Murphy, N. Rosenberg, D. Shumaker, C. San Soucie, S. Smith, A. Tompson, "Modeling Groundwater Flow Through Heterogeneous Porous Media on Massively Parallel Computers," *SuperComputing 1996*. [PDF]

40. Mirin, A.A., D.E. Shumaker, and M.F. Wehner, "Efficient Filtering Techniques for Finite-Difference Atmospheric General Circulation Models on Parallel Processors," submitted to *Parallel Computing* (1997).

41. Tompson, A.F.B., N.D. Rosenberg, W.J. Bosl, R.D. Falgout, S.G. Smith, D.E. Shumaker, S.F. Ashby, "On the Use of High-Performance Simulation in the Management of Groundwater Resources in Large Aquifer Systems," *XXVII IAHR Congress on Water for a Changing Global Community*, San Francisco, CA, August 10—15, 1997. Available as Lawrence Livermore National Laboratory technical report UCRL-JC-126359. [PDF]

42. Tompson, A.F.B., C.J. Bruton, G.A. Pawloski, W.L. Bourgier, S.F. Carle, A.B. Kersting, J.A. Rard, D. E. Shumaker, and D.K. Smith, "Evaluation of the Hydrologic Source Term from Underground Nuclear Tests in Frenchman Flat at the Nevada Test Site: The CAMBRIC Test," available as Lawrence Livermore National Laboratory technical report UCRL-ID-132300, March 1999.

43. Dimits, A.M., B.I. Cohen, N. Mattor, W.M. Nevins, D.E. Shumaker, S.E. Parker, and C. Kim, "Simulation of Ion-Temperature-Gradient in Tokamaks," Nuclear Fusion, 40 (2000), p. 661.

44. Dimits, A.M., G. Bateman, M.A. Beer, B.I. Cohen, W. Dorland, G.W. Hammett, C. Kim, J.E. Kinsey, M. Kotschenreuther, A.H. Kritz, L.L. Lao, J. Mandrekas, W.M. Nevins, S.E. Parker, A.J. Redd, D.E. Shumaker, R. Sydora and J. Weiland, "Comparisons and Physics Basis of Tokamak Transport Models and Turbulence Simulations," Physics of Plasmas, 7 (2000), p. 969.

**Abstracts and Reports**

1. McCoy, M.G., J. Killeen, A.A. Mirin, M.E. Rensink, and D.E. Shumaker, "Fokker-Planck/Transport Model of Non-Circular Axisymmetric Devices," *Bull. Am. Phy.* **22**, 1116 (1977).

2. Mirin, A.A., M.G. McCoy, J. Killeen, and D.E. Shumaker, "FPTE, A Super-hybrid Fokker-Planck /Transport /Equilibrium /Monte Carlo Neutrals Code for Non- Circular Tokamaks," *Eighth Conference on Numerical Simulation of Plasmas*, Monterey, CA, 1978.

3. Shumaker, D.E., M.G. McCoy, J. Killeen, and A.A. Mirin, "Two Transport Models for Non-Circular Axisymmetric Devices," *Sherwood Meeting, Theoretical Aspects of Controlled Thermonuclear Research*, Mount Pocono, PA, 1979.

4. Shumaker, D.E., B. McNamara, and J.K. Boyd, "Field-Reversed Mirror Transport Code," *Bull. Am. Phy.* **24**, 955 (1979).

5. Auerbach, S.P., H.L. Berk, J.K. Boyd, B. McNamara, and D.E. Shumaker, "Two Dimensional Time Dependent Transport in Field Reversed Equilibria," *US-Japan Joint Symposium on Compact Torus and Energetic Particles Injection*, Princeton, NJ, 1979.

6. Shumaker, D.E., J.K. Boyd, S.P. Auerbach, H.L. Berk, and B. McNamara, "Field- Reversed Mirror Transport Code," *Sherwood Meeting, Theoretical Aspects of Controlled Thermonuclear Research*, Tucson, AZ, and in *Proceedings of the 9th Conference on Numerical Simulation of Plasma*, Evanston, IL, 1980.

7. Shumaker, D.E., J.K. Boyd, S.P. Auerbach and B. McNamara, "Transport in Field-Reversed Mirror," *Bull. Am. Phys.* **25** No. 8, 979 (1980).

8. Shumaker, D.E., J.K. Boyd, S.P. Auerbach and B. McNamara, "Reversed-Field Mirror Transport Code," *Third Symposium on the Technology of Compact Toroids*, Los Alamos, NM, 1980.

9. Shumaker, D.E., J.K. Boyd, S.P. Auerbach, and B. McNamara, "Numerical Simulation of the Beta II Experiment," *Annual Controlled Fusion Theory Conference*, Austin, TX, 1981.

10. Shumaker, D.E., J.K. Boyd, B. McNamara, and W.C. Turner, *Numerical Simulation of the Beta II Experiment*, Lawrence Livermore National Laboratory technical report UCRL-85579 (1981). [PDF]

11. Shumaker, D.E., J.K. Boyd, B. McNamara, and W.C. Turner, "Numerical Simulation of a Beam Heated Compact Torus," *Bull. Am. Phys.* **26**, 881 (1981).

12. Auerbach, S.P., and D.E. Shumaker, "Ion Thermal Conduction in Compact Toroids; Comparison of Theory, Simulation and Experiments," *Bull. Am. Phys.* **27**, 1113 (1982).

13. Shumaker, D.E., "Equilibrium Calculation of Compact Toroids Using a Flux Surface Coordinate System," *10th Conference on Numerical Simulation of Plasmas*, San Diego, CA, 1983.

14. Shumaker, D.E., D.Q. Hwang and S.C. Jardin, "Equilibrium and Stability of the Davis Diverted Tokamak," *1987 Sherwood Conference, *San Diego, CA.

15. Horowitz, E.J. and D.E. Shumaker "3-D Hybrid Code to Model the Tilt Mode in FRC," *Eighth Compact Toroid Symposium*, College Park, MD, 1987. [PDF].

16. Shumaker, D.E., A.A. Mirin, and E.J. Horowitz, "Simulation of the Tilt Mode in the FRC," *Bull. Amer. Phys. Soc.* **32**, 1723 (1987).

17. Shumaker, D.E., *Transport in a Field-Reversed Configuration: Comparison of Simulation and Experiment*, Lawrence Livermore National Laboratory technical report UCRL-94433 (1987).

18. Flittner, D., K. Bradley, J. DeGroot, T. Hillyer, D.Q. Hwang, K. Mizuno, G. Dimonte, and D. Shumaker, "Design and Initial Operation of the Davis Diverted Tokamak," *Bull. Amer. Phys. Soc.* **32**, 1905 (1987).

19. Shumaker, D.E., A.A. Mirin and J.H. Hammer, "MHD Simulation of Tokamak Fueling by the Injection of Compact Toroids," *1988 Sherwood Conference*, Gatlinburg, TN.

20. Shumaker, D.E., "3-D Hybrid Particle Simulation of the Tilt Mode in the Field- Reversed Configuration", *Bull. Amer. Phys. Soc.* **33**, 2003 (1988).

21. Hwang, D.Q., D.E. Shumaker, and D. Flittner, "Axisymmetric Stability Simulation of the Davis Diverted Tokamak," *Bull. Amer. Phys. Soc.* **33**, 2049 (1988).

22. Anderson, D.V., D.E. Shumaker, and E.J. Horowitz, "Plasma Simulation in 3D from Parallel Computing: Modeling the Tilt Instability," *International School of Plasma Physics*, Varenna, 1988.

23. Mirin, A.A., D.E. Shumaker and J.H. Hammer, "MHD Modeling of the Fueling of a Tokamak Reactor by Compact Toroids," *Annual Controlled Fusion Theory Conf*., 2D7 (1989), San Antonio, TX.

24. Anderson, D.V., D.E. Shumaker, E.J. Horowitz and D. Porter, "3-D Animation of Particles and Fields in the QN3D Plasma Simulation Code," *13th Conference on the Numerical Simulation of Plasmas*, Santa Fe, NM, September 1989.

25. Shumaker, D.E., A.A. Mirin and J.H. Hammer, "MHD Simulation of the Fueling of a Tokamak Reactor by Compact Toroids," *Bull. Amer. Phys. Soc.* **34**, 1970 (1989).

26. Thomas, J., D. Q. Hwang, T. Hillyer, G. Dimonte, J. H. Rogers, and D. E. Shumaker, "Initial Operation of the Davis Diverted Tokamak (DDT)," *Bull. Amer. Phys. Soc.* **34**, 2165 (1989).

27. Anderson, D.V., B.C. Curtis, D.E. Shumaker and E.J. Horowitz, "Obtaining Gigaflop Performance From Particle Simulations of Plasma," *5th International Conference on Science and Engineering on Supercomputers*, p. 297 (1990), London, U.K. [PDF]

28. Anderson, D.V., B.C. Curtis, D.E. Shumaker and E.J. Horowitz, "Parallel Simulation of Plasmas by an Ordered Particle Scheme," (1990).

29. Shumaker, D.E., "Simulation of the Tilt Mode in the Field-Reversed Configuration Using a 3-D Hybrid Particle Code," *Bull. Amer. Phys. Soc.* **35**, 2116 (1990).

30. Anderson, D.V., B.C. Curtis and D.E. Shumaker, "Hybrid Ordered Particle Simulation (HOPS) Code for Three-Dimensional Plasmas," *Bull. Amer. Phys. Soc*. **35**, 1999 (1990).

31. Byers, J.A., D.V. Anderson, B.I. Cohen, D.E. Shumaker and G.F. Simonson, "Quasineutral Algorithms for 2D and 3D Simulations of Space Plasmas," *Bull. Amer. Phys. Soc.* **35**, 1999 (1990).

32. Anderson, D.V. and D.E. Shumaker, "Sorting Algorithms for Hybrid Ordered Particle Simulations of 3-D Plasmas," *Bull. Amer. Phys. Soc.* **36**, 1784 (1991).

33. Shumaker, D.E., "Hybrid Particle Code Simulations of Expanding Plasmas," *Bull. Amer. Phys. Soc.* **35**, 2307 (1991).

34. Simonson, G.F., D.W. Hewitt, D.E. Shumaker, D.V. Anderson, J.A. Byers, and G. DiPeso, "Numerical Simulation of Interactions of Nuclear Weapons with the Geomagnetic Field," *1992 Sensor Technical Conference*, Florida, May 13—14, 1992. Available as Lawrence Livermore National Laboratory technical reportUCRL-JC-109841 (1992).

35. Anderson, D.V., and, D. E. Shumaker, "Particle Simulation Methods for MIMD Parallel Computers," *Bull. Amer. Phys. Soc.* **37**, 1506 (1992).

36. Shumaker, D.E., and D. V. Anderson, "Expanding Plasma Simulations Using the Hybrid Particle Code HOPS," *Bull. Amer. Phys. Soc.* **37**, 1506 (1992).

37. Anderson, D.V., and D. E. Shumaker, "Parallel Deposition, Sorting, and Reordering Simulation (HOPS) Code," *Controlled Fusion Theory Conference*, 1993.

38. Dimonte, Guy, Larry Wiley, Greg Simonson, and Dana Shumaker, "Laser-Plasma Experiments Simulating Ionospheric Explosions," *23rd Anomalous Absorption Conference*, 1993.

39. Anderson, D.V., and Dan E. Shumaker, "Efficient Operating Regimes of the Hybrid Ordered Plasma Simulation Code: HOPS," *Physics of Computing*.

40. Anderson, D.V., and D.E. Shumaker, "Ordered Particle Versus Ordered Pointers in the Hybrid Ordered Particle Simulation (HOPS) Code," *Bull. Amer. Phys. Soc.* **38**, 1992 (1993).

41. Shumaker, D.E., G.D. Kerbel and R.E. Waltz, "Parallel Advection in Tokamak Gryo-Landau Fluid Turbulence Simulation," *Bull. Amer. Phys. Soc.* **38**, 2102 (1993).

42. Mirin, A.A., J. Bolsted, J.C. Brown, B. Chan, W.P. Dannevik, P.G. Eltgroth, B. Grant, P. Rouvillois, D.E. Shumaker, and M.F. Wehner, "High Performance Ocean/Atmosphere Modeling Using a Domain Decomposition Message-Passing Approach," *SuperComputing'93*, Portland, OR November 1993, p.76 (1993).

43. Shumaker, D.E., and G.D. Kerbel, "Semi-Lagrangian Advection in Tokamak Gyrofluid Turbulence Simulations," *Sherwood Fusion Theory Conference*, Dallas, TX, 1994.

44. Kerbel, G.D., D.E. Shumaker, R.E. Waltz, G.H. Hammett, M.A. Beer, A. Verlo, "Multi-supercomputing on the I-way,"* APS* **4Q**,** **24, Louisville KY, November 1995.

45. Dimits, A.M., B.I. Cohen, L.L. Lao, D.E. Shumaker, B.W. Stallard, and T.J. Williams, "Nonlinear Gyrokinetic Simulation of Transport in DIII-D with Sheared Rotation," *Bull. Amer. Phys. Soc.* **41**, 1413 (1996).

46. Dimits, A.M., D.E. Shumaker and B.I. Cohen, "Issues in Nonlinear Simulations of Toroidal ITG Turbulence and Transport,"* 6th Annual Numerical Tokamak Turbulence Workshop*, University of Wisconsin, April 30—May 1, 1997.

47. Ashby, S.F., D.E. Shumaker, et al., "Modeling Groundwater Flow through Heterogeneous Porous Media on Massively Parallel Computers," *SuperComputing'97*, San Jose, CA, November 1997.

48. Dimits, A.M., B.I. Cohen, D.E. Shumaker, and S.E. Parker, "Nonlinear Gyrokinetic Simulations of Tokamak Turbulence and Transport," *Bull. Am. Phys. Soc.* **42** (1997).

49. Dimits, A.M., D.E. Shumaker, W.M. Nevins, B.I. Cohen, and S.E. Parker, "Numerical Convergence and Raised Nonlinear Thresholds in ITG Turbulence," *11th Transport Task Force Workshop*, Atlanta, GA, March 1998.

50. Nevins, W.M., A.M. Dimits, and D.E. Shumaker," Self-Organized Criticality in Gyrokinetic Simulations of ITE Turbulence,"* 11th Transport Task Force Workshop*, Atlanta, GA, March 1998.

51. Dimits, A.M., D.E. Shumaker, W.M. Nevins, B.I. Cohen, and S.E. Parker, "Raised Nonlinear Thresholds and Numerical Convergence in Gyrokinetic Simulations of Ion-Temperature-Gradient Turbulence in Tokamaks,"* International Sherwood Fusion Theory Conference*, Atlanta, GA, March 1998. Available as Lawrence Livermore National Laboratory technical report UCRL-JC-902522 (1998). [PDF]

52. Thompson, A.F.B., C.J. Bruton, W.L. Bourcier, D.E. Shumaker, S.F. Carle and G.A. Pawloski, "Near-Field Migration of Radionuclides in Groundwater away from an Underground Nuclear Test," *American Geophysical Union 1998 Fall Meeting*, San Francisco, CA, December 6—10, 1998. Also available as Lawrence Livermore National Laboratory technical report UCRL-JC-131553-abs. [PDF]

53. Dimits, A.M., D.E. Shumaker, W.M. Nevins, B.I. Cohen and S.E. Parker, "Progress in Flux-Tube Gyrokinetic Simulations of Tokamak Ion-Temperature-Gradient Turbulence," *US-Japan Workshop on Turbulence and Transport in Toroidal Plasmas*, 1998. Also available as Lawrence Livermore National Laboratory technical report UCRL-JC-129487-abs. [PDF]

54. Dimits, A.M., B.I. Cohen, N. Mattor, W.M. Nevins, D.E. Shumaker, S.E. Parker and C. Kim, "Simulation of Ion-Temperature-Gradient Turbulence in Tokamaks," *17th International Atomic Energy Agency, Fusion Energy Conference*, 1998. Also available as Lawrence Livermore National Laboratory technical report UCRL-JC-130166-abs. [PDF]

55. Dimits, A.M., D.E. Shumaker, W.M. Nevins, B.I. Cohen and S.E. Parker, "Numerical Convergence of Gyrokinetic Simulations of Ion-Temperature-Gradient Turbulence," *16th International Conference on Numerical Simulation of Plasmas*, Santa Barbara, CA, February 10—12, 1998. Also available as Lawrence Livermore National Laboratory technical report UCRL-JC-129485-abs. [PDF].

56. Nevins, W.M., A.M. Dimits and D.E. Shumaker, "A Study of Fluctuations in Gyrokinetic Simulations of ITG Turbulence," *Bull. Am. Phys. Soc.* **43** (1998).

57. Dimits, A.M., B.I. Cohen, W.M. Nevins and D.E. Shumaker, "Progress in Nonlinear Gyrokinetic Simulation," Bull.* Am. Phys. Soc.* **43** (1998).

58. Dimits, A.M., B.I. Cohen, W.M. Nevins, and D.E. Shumaker, "Global Effects and Local Scalings in Toroidal ITG Turbulence," Bull. Am. Phys. Soc., 44 (1999), p. 302.

59. Shumaker, D.E., A.M. Dimits, B.I. Cohen, and W.M. Nevins, "Progress in Gyrokinetic Simulation of Tokamak Turbulence," Bull. Am. Phys. Soc., 44 (1999), p. 301.

60. Nevins, W.M., B.I. Cohen, Dimits, A.M., D.E. Shumaker, Z. Lin, and S.E. Parker, "Diagnosing Simulations of Plasma Turbulence," Bull. Am. Phys. Soc., 44 (1999), p. 261.

61. Dimits, A.M., B.I. Cohen, W.M. Nevins, and D.E. Shumaker, "Transport due to Toroidal ITG Turbulence: Local Scalings and Nonlocal Effects," International Sherwood Fusion Theory Conference 2000.