SPG Marx Model Rev a
!
! Rick Spielman 2016-05-13
!
Time-step 0.05e-9
Resolution-time 0.5e-9
End-time 1e-6
Number-prints 5
Execute-cycles all
Grids no
Echo-setup no
Max-points 5001
!
!Start base circuit definition
!
! We start with a lumped marx design.
! 16 stages X 3*80 nF caps per stage - C = 240 nF / 16  = 15 nF
! Cap ESR = 0.13 /3, Total cap ESR = 0.13 * 16/3 = 0.693 
! L per stage = 20 nH/3 L Marx caps = 20 nH * 16/3 = 104 nH
! L per switch from SNL = 120 nH, L switch total = 120 nH * 8 = 960 nH
! L load resistor = 136 nH
! L total = 1200 nH
! R load = 10 
!
! The charge voltage will be 55 kV. The initial cap voltage is 55 * 16 = 880 kV
! The Marx switch resistance will be a) fixed - best fit, b) exponential - best fit, c) Martin Model
!
!#1 Base version - too much damping, zero crossing late
!#2 Lower R to 8.5  - right damping, zero crossing OK
!#3 R=9, C lower by .91, L increased 1/.91
!#4 R=9.05, C lower by .9009, L increased 1/.9286 - fits Ip,Iundershoot, tcross
!
BRANCH
!
! Capacitor capacitance and charge voltage
!
RCGround 1e+12 13.5135e-9
Initial VC1 880e3
UFO VC1
$V_marx
!
! Cap inductance, case & parasitic inductance, and ESR
!
RLSeries 0.693 104e-9
!
! Switch resistance and switch inductance - estimated
!
RLSeries 0.050 1052.3e-9
!
! Output Marx header inductance
!
RLSeries 0.00 136e-9
!
! Load resistance = 10 
!
RCGround 9.05 0.0
!
UFO IR1
$I_marx
UFO VR1
$V_out
UFO PR1
$P_load
UFO ER1
$E_load
!
! End Branch
!
! End circuit
!