BIOGRAPHY

Mr. Pappas joined The Center for Electromechanics in May 1996.  He is the Program Manager and chief electrical engineer for the ElectromagneGun Program, which consists of two multi-million dollar efforts.  The goal of the first of these efforts is the demonstration of a very high power, lightweight converter.  The goal of the second of these is the development of a new, very high power density alternator.  In 2000 he developed a proposal and completed the design of a high-voltage dc-dc converter for use in NASA’s space program.

Mr. Pappas was previously employed by Parker Kinetic Designs, Inc., as manager of PKD’s power supply and electromagnetic launch group.  He served as program manager and principal engineer for the Battery Upgrade Supply, Electromagnetic Aircraft Launcher System, Light Gas Accelerator, UK Royal Armament EML facility design, FTP switch development and test, and IAT pulse-forming inductor projects.  As Engineering Manager, Mr. Pappas was responsible for project management, customer interface, system and component design and engineering, component manufacturing, and system test.

Before joining PKD, Mr. Pappas served as Liaison Officer for the U.S. Army Armament Research, Development and Engineering Center (U.S. Army ARDEC) field office at The Center for Electromechanics from 1986 to 1988.  In addition, he was a visiting engineer at The Center for Electromechanics, involved in the development and test of high current sliding contacts and armatures.

Mr. Pappas was an electrical engineer at U.S. Army ARDEC from 1981 to 1986.  He was responsible for range, accelerator, and power supply (homopolar generator and capacitor banks) instrumentation; design, and assembly of the data acquisition system; and design and fabrication of high current air core pulse transformers.  He also designed and built high-current bus and switching systems used on the homopolar generator test system.  

Prior to his position at U.S. Army ARDEC, Mr. Pappas was a computer programmer for Integrated Resources, Inc. in East Orange, New Jersey.  He has also served as an independent consultant.  He has worked recently with a start–up company that markets a novel coating removal process and as an expert witness in a patent infringement case involving drive systems for servo and stepper systems.

CURRENT PROJECTS

• NGES: “Railgun Innovative Navy Prototype Launcher Concept Study”
• Sandia Laboratories: “Investigate Electromagnetic Missile Launcher Topologies”
• NGMS: “Composite Barrel Design Trade Study”
• NGES: “Composite Manufacturing Processes”
• NGES: “Railgun Innovative Navy Prototype Launcher Concept Study”
• Curtiss Wright: “Pulsed Power EM Guns”
• ARDEC: “Advanced Component Development”
• ARL: “Materials Development”
• UT Physics Department: “PFN Design”

ABOUT ME (Awards, Memberships, etc.)

• Registered Professional Engineer
• 1988 co-chairman of the Session on Armatures at the 4th IEEE Symposium on Electromagnetic Launch Technology
• 1992 co-chairman of the Session on Power Supplies at the 6th IEEE Symposium on Electromagnetic Launch Technology
• Member of the DARPA National Electric Gun Program Study

EDUCATION

• M.S. Electrical Engineering, University of Texas at Austin, 1988
• B.S. Electrical Engineering, New Jersey Institute of Technology, 1983

PUBLICATIONS

• R.E. Hebner, J.A. Pappas, J.R. Kitzmiller, K.R. Davey, J.D. Herbst, A. Ouroua, and J. H. Beno, “Some benefits of pulsed alternators as electromagnetic gun power supplies in power systems for future electric ships,” Engine as a Weapon II, London, United Kingdom, December 5-6, 2006 (PR 444).

• R.E. Hebner, et al., “An electromagnetic gun power supply as a component of an electric ship power system,” ASNE High Powered Weapon Systems for Electric Ship 2004, Annapolis, Maryland, U.S.A., December 7-9, 2004 (PN 292).

• M. Elmore, et al., “Optimum design of snubber circuits for thyristor assemblies using an improved PSPICE thyristor model and computational intelligence,” Digest of Technical Papers, 14th IEEE International Pulsed Power Conference (PPC-2003), June 15-18, 2003, vol. 1, pp. 139-142 (PN 301).

• J.A. Pappas, A.L. Gattozzi, and R.E. Hebner, “Pulsed-duty characterization of turn-off for a population of SCRs and the practical effect of variations on equalization circuit design,” IEEE Transactions on Magnetics, vol. 39, no. 1, January 2003, pp. 432-436 (PR 307).

• A.L. Gattozzi and J.A. Pappas, “Circuits for protecting and triggering SCRs in high-power converters,” IEEE Transactions on Magnetics, vol. 39, no. 1, January 2003, pp. 414-417 (PR 296).

• A.L. Gattozzi, S.P. Pish, and J.A. Pappas, “Effect of converter packaging techniques on device electrical conduction,” IEEE Transactions on Magnetics, vol. 39, no. 1, January 2003, pp. 418-421 (PR 297).

• H. Zhang and J.A. Pappas, “A moving boundary diffusion model for PIN diodes,” IEEE Transactions on Magnetics, vol. 37, no. 1, January 2001, pp. 406-410 (PR 272).

• J.R. Kitzmiller, et al., “Predicted vs. actual performance of a model scale compulsator system,” IEEE Transactions on Magnetics, vol. 37, no. 1, January 2001, pp. 362-366 (PR 276).

• J.R. Kitzmiller, J.A. Pappas, S.B. Pratap, and M.D. Driga, “Single and multiphase compulsator system architectures: a practical comparison,” IEEE Transactions on Magnetics, vol. 37, no. 1, January 2001, pp. 367-370 (PR 277).

• J.A. Pappas and D.E. Piccone, “Power converters for railguns,” IEEE Transactions on Magnetics, vol. 37, no. 1, January 2001, pp. 379-384 (PR 281).

• J.A. Pappas, S.P. Pish, and M.J. Salinas, “Characterization of triggered vacuum switches for high current operation,” IEEE Transactions on Magnetics, vol. 35, no. 1, January 1999, pp. 367-371 (PR 243).

• G.R. Headifen, et al., “Preliminary design of a 1 GJ homopolar generator,” IEEE Transactions on Magnetics, vol. 29, no. 1, January 1993, pp. 980-985 (PR 180).

• J.A. Pappas, G.R. Headifen, J.M. Weldon, J.C. Wright, R.C. Zowarka, T.A. Aanstoos, and J.H. Kajs, “Design of a 500 MJ, 5 MA Power Supply,” IEEE Transactions on Magnetics, vol. 29, no. 1, part 2, January 1993, pp. 1027-1032 (PR 397).

• R.C. Zowarka, et al., “A new approach to a high efficiency inductive store,” IEEE Transactions on Magnetics, vol. 27, no. 1, January 1991, pp. 384-389 (PR 121).

• J.H. Gully, M.L. Spann, S.B. Pratap, and J.A. Pappas, “Power systems for electrothermal guns,” 26th Joint Army-Navy-NASA-Air Force Combustion Meeting, Jet Propulsion Laboratory, Pasadena, California, U.S.A., October 23-27, 1989 (PN 163).

• J.A. Pappas, M.D. Driga, and W.F. Weldon, “Physical scale modeling to predict current diffusion in solid armatures,” IEEE Transactions on Magnetics, vol. 25, no. 1, January 1989, pp. 408-411 (PR 84).

• J.H. Price, et al., “Design and testing of solid armatures for large-bore railguns,” IEEE Transactions on Magnetics, vol. 25, no. 1, January 1989, pp. 467-473 (PR 66).

• H. Singh, D. Eccleshall, I. McNab, and J. Pappas, “Alternator power conditioning for launchers,” Proceedings, New Frontiers in Testing, International Test Conference, September 12-14, 1988, pp. 744-751 (PN 239).

• J.H. Price, et al., “Results of monolithic solid armature tests in a railgun,” 1987 International Current Collector Conference, Austin, Texas, U.S.A., November 16-17, 1987 (PN 134).

• J.A. Pappas, M.D. Driga, and W.F. Weldon, “High current coaxial pulse transformer for railgun applications,” IEEE Pulsed Power Conference, Arlington, Virginia, U.S.A., June 10-12, 1985 (PR 30).