RESISTIVITY AND HEAT CONDUCTION MODELING IN CAPILLARY DISCHARGES*

We studied the impact of resistive and thermal transport on capillary waveguide [1] performance as part of an effort to understand and quantify uncertainties in modeling and designing next-generation plasma accelerators. First, the Ji-Held [2] electron transport model was added to the adaptive mesh refinement magnetohydrodynamics code [3], FLASH, and tested against Braginskii [4] and Epperlein-Haines [5] models. The simulations enable us to investigate the performance of argon and hydrogen-filled capillaries discharge. Typically computed diagnostics include azimuthal magnetic field, average ionization state, and temperature fields. We present 2D cylindrical geometry simulations and compare them against theoretical and experimental predictions. Finally, we will discuss how changes to the laser heater affect plasma transport.

1] W. P. Leemans et al., Phys. Rev. Lett.113, 245002.

[2] J.-Y. Ji and E. D. Held, Physics of Plasmas20, 042114 (2013).

[3] B. Fryxell, K. Olson, P. Ricker, F. X. Timmes, M. Zingale, D. Q. Lamb, P. MacNeice, R. Rosner, J. W. Truran, and H. Tufo, ApJS 131, 273 (2000).

[4] S. I. Braginskii, Soviet Journal of Experimental and Theoretical Physics6, 358 (1958).

[5] E. M. Epperlein and M. G. Haines, Physics of Fluids 29, 1029 (1986).