Numerical Analysis of a Pulsed Compact LTD System for Electron Beam-Driven Radiography

This paper describes the configuration and operation of a seven-cavity linear transformer driver (LTD) system. This LTD system is configured to deliver ~1 MV and 125 kA into a critically damped load. A detailed transmission line model coupled to particle-in-cell simulations is used to assess the system electrical performance. The evolution of the electron power flow in negative polarity is simulated, and the impact of this flow on the operation of the system with a large-area hollow electron beam diode is examined. The simulation results are compared with available electrical measurements and with dose rate measurements where a flash X-ray pulse is produced by an annular electron beam diode. These comparisons suggest that the LTD system meets the design specifications and is a robust pulsed power architecture. Additionally, the positive polarity operation for the LTD system driving a rod-pinch diode load is modeled to further assess the utility of the LTD system

[1]  Joshua R. Smith,et al.  Intense electron beam sources for flash radiography , 2002, 2002 14th International Conference on High-Power Particle Beams (BEAMS).

[2]  Boris M. Kovalchuk,et al.  Development of the ultra-fast LTD stage , 2002, 2002 14th International Conference on High-Power Particle Beams (BEAMS).

[3]  J. Huba.  NRL: Plasma Formulary , 2004 .

[4]  Ian Smith,et al.  Advances in pulsed power-driven radiography systems , 2004, Proceedings of the IEEE.

[5]  D D Hinshelwood,et al.  BERTHA - A Versatile Transmission Line and Circuit Code , 1983 .

[6]  I. Smith.  Induction voltage adders and the induction accelerator family , 2004 .

[7]  Wayne R. Meier,et al.  Fusion energy with lasers, direct drive targets, and dry wall chambers , 2003 .

[8]  J. R. Boller,et al.  Theoretical modeling and experimental characterization of a rod-pinch diode , 2001 .

[9]  B. Weber,et al.  Ultra-high electron beam power and energy densities using a plasma-filled rod-pinch diode , 2004 .

[10]  John R. Smith,et al.  Performance of the Cygnus x-ray source , 2002, 2002 14th International Conference on High-Power Particle Beams (BEAMS).

[11]  J. J. Condon,et al.  Impedance characteristics of diodes operating in the self−pinch mode , 1975 .

[12]  S. Portillo,et al.  Design, Simulation, and Fault Analysis of a 6.5-MV LTD for Flash X-Ray Radiography , 2006, IEEE Transactions on Plasma Science.

[13]  S. N. Volkov,et al.  Primary energy storages based on linear transformer stages , 2003 .

[14]  D. Rovang,et al.  Optimization of a rod pinch diode radiography source at 2.3 MV , 2003 .

[15]  R. Commisso,et al.  Particle-in-cell simulations of high-power cylindrical electron beam diodes , 2000 .

[16]  C. Birdsall,et al.  Plasma Physics via Computer Simulation , 2018 .

[17]  M. Cuneo,et al.  Architecture of petawatt-class z-pinch accelerators. , 2007 .

[18]  G. D. Valdez,et al.  ITS: the integrated TIGER series of electron/photon transport codes-Version 3.0 , 1991, Conference Record of the 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference.

[19]  D. Rovang,et al.  Coupled particle-in-cell and Monte Carlo transport modeling of intense radiographic sources , 2002 .

[20]  F.W. Long,et al.  Ultrafast LTD's for bremsstrahlung diodes and Z-pinches , 2001, PPPS-2001 Pulsed Power Plasma Science 2001. 28th IEEE International Conference on Plasma Science and 13th IEEE International Pulsed Power Conference. Digest of Papers (Cat. No.01CH37251).

[21]  Paul C. Kepple,et al.  Electron beam pumped krypton fluoride lasers for fusion energy , 2004, Proceedings of the IEEE.

[22]  A.N. Bastrikov,et al.  1 MV ultra-fast LTD generator , 2003, Digest of Technical Papers. PPC-2003. 14th IEEE International Pulsed Power Conference (IEEE Cat. No.03CH37472).