DE-R Four Module + Load Model
!
! Rick Spielman 2017-06-09
!
Time-step 2.0e-12
Resolution-time 0.1e-9
End-time 1.0e-6
Number-prints 5
Execute-cycles all
Grids no
Echo-setup no
Max-points 5001
!
!Start circuit definition
!
! DE-R Rev 2 uses the DE-R Rev 1 deck with 4 parallel modules that are driving an insulator stack, MITL, and e-beam load.
!
! DE-R Rev 1 uses the DE Rev 4 as the baseline. We will be changing all the line impedances to
! 2  and will be changing the line lengths. The goal here is to have a driver that delivers a clean 100-ns FWHM pulse to a constant impedance load.
!
! Rev 4 changes the CPL water switch gap to the actual gap 3.75
! also changes the output line to constant 1.3  impedance with a matched load.
!
! Rev 3 Marx switch losses and more accurate water line parameters
! Change marx to 30 stages of 300 nF/stage
!
! Gas switch dimensions from drawings
!
! We start with a total Marx capacitance of 100 nF (exceeds the CPL capacitance). This implies
!   that there will a ringing gain on the CPL. This allows a faster rise time than otherwise to 
!   get to the desired CPL voltage.
!
! CPL capacitance used is 60 nF. This is distributed in a TL that is 85 ns long and
!   has a constant impedance of 1.4 . (C = t/Z = 85/1.4 nF = 60.71 nF)
!
! The sub Marx capacitance is 10 nF at a charge voltage of 100 kV.
! We have a 10-nF sub Marx with 30 cap pairs in series and 15 switches. Vch = 3 MV
! We have 10 sub Marxes in parallel.
! the total Marx capacitance is 100 nF.
! Include 130 m individual cap ESR or 65 m per pair of caps in parallel
!   X 30 stages = 1.95  per sub-Marx
! Assume that there will be 200 nH every two stages. L = 200 nH * 15 = 3.0 H.
!   The total Marx inductance (caps and switches) would be 3.0 H/10 = 300 nH
!
! The matched impedance of a single Marx = sqrt(L/C) = 17.3 .
!   The total Marx impedance is 17.3 /10 = 1.73 
! Note CPL impedance is 1.4 . (12 sub-marxes would match)
! The ESR amounts to ~ 11.3% of the matched impedance.
!
! The switch model will have 15x the length of one switch per sub Marx and then will
! have 10 arc channels (sub Marxes) in parallel.
! 
! We will use a total inductance of 380 nH for the Marx and L1. This inductance is needed to 
! get the required rise time of the voltage on the CPL.
!
! 
!
BRANCH
!
! Marx capacitance and charge voltage - 4XC and L/4, ESR/4
!
RCGround 1e+12 400e-9
Initial VC1 3.0e6
UFO VC1
$V_marx
!
! Cap inductance, case & parasitic inductance, and ESR
! ESR = 0.195 for the total Marx (1.95 /10)
!
RLSeries 0.049 62.5e-9
!
! Switch resistance - Martin Model and switch inductance - the total gap for a single
!   switch from DWGs is 0.53 (1.346 cm) gap and 93 psig air X15 = 20.19 cm
!
! Initial switch resistance was chosen to be higher than that printed in the first
! few time steps so as to appear monotonically decreasing in R plots
! A careful few runs showed that 10 G looked best. In any event by 1 ns all of the 
! resistance values are the same.
!
RLSeries 10e9 12.5e-9
Var R2 Switch
!dielectric switchtime gap      pressure     nswitch  nchannels
AIR            0.0             0.2019   7.3              10          4
UFO IR2
$I_marx
UFO R2
$R_switch
UFO ER2
$E_switch
UFO QR2
$Q_switch
!
! Output Marx header inducatance - divide by 4
!
RLSeries 0.00 25e-9
!
! Line 1 (CPL), 50 ns, 2   - Divide by 4
!
TRLine LIN 50e-09 0.5 0.5
UFO VOUT
$V_CPL_out
UFO IOUT
$I_CPL_out
UFO POUT
$P_CPL_out
UFO EOUT
$E_CPL_out
!
! CPL Output water switches - Increase switches by 4, divide L/4
! 5 output switches, 4 gap + switch inductance
!
RLSeries 10e9 2.5e-9
Var R2 Switch
!dielectric switchtime gap      pressure   nswitch  nchannels
H2O         270e-09    0.1016   1.0             20             1
UFO IR2
$I_CPL_sw
UFO R2
$R_CPL_sw
UFO ER2
$E_CPL_sw
UFO QR2
$Q_CPL_sw
!
! Line 2, 72 ns, 2  constant impedance - divide by 4, increase switches by 4
!
TRLine LIN 72e-09 0.5 0.5
UFO VIN
$V_PFL_in
UFO VOUT
$V_PFL_out
UFO IOUT
$I_PFL_out
UFO POUT
$P_PFL_out
UFO EOUT
$E_PFL_out
!
! Line 2 Output water switches - increase switches x4, divide L/4
! 7 output switches, 0.5 gap
!
RLSeries 10e9 2.5e-9
Var R2 Switch
!dielectric switchtime gap      pressure     nswitch  nchannels
H2O         360e-09    0.0127   1.0                    28               1
UFO IR2
$I_PFL_sw
UFO R2
$R_PFL_sw
UFO ER2
$E_PFL_sw
UFO QR2
$Q_PFL_sw
!
! Output Line (OL),  72 ns, 2  constant impedance - divide by 4
!
TRLine LIN 72e-09 0.5 0.5
UFO VIN
$V_OL_in
UFO VOUT
$V_OL_out
UFO IOUT
$I_OL_out
UFO POUT
$P_OL_out
UFO EOUT
$E_OL_out
!
!   ***********************  Insulator stack  *****************************
! The water/vacuum interface Router=1.1 m, Rinner=1.0 m, height=13.75 cm (1 cm grading rings) 
! Two stacks in parallel - divide L by 2
!
RLS  1.0E-12    1.25E-9
!
UFO VOUT
$V_stack
UFO IOUT
$I_stack
UFO POUT
$P_stack
UFO EOUT
$E_stack
!
!   **************************  Vacuum flares  *****************************
! Two vacuum flares in parallel - divide by 2
!
RLS  1.0E-12    1.58E-9
!
UFO VOUT
$V_vf
UFO IOUT
$I_vf
UFO POUT
$P_vf
UFO EOUT
$E_vf
!
!   *****************************   MITLs   ********************************
!
TRLine LIN 2.47e-09 2.0 2.0
!
UFO VOUT
$V_mitls
UFO IOUT
$I_mitls
UFO POUT
$P_mitls
UFO EOUT
$E_mitls
!
!   *******************  Inner-MITL-coax  ********************
!
TRLine LIN 0.75e-09 2.0 2.0
!
! Extra inductance budget
RLS 0.0       0.5E-9
!
UFO IR2
$I_coax
!
!  ******************** e-Beam Diode Resistance *******************
!
RCGround 1e6 0.0
VARiable R1 EDIode
!Diode_type Gap  Enhancement Velocity Router   (Rinner)
3                     5e-3 1.0                     0.0         0.16        0.15
!
UFO R1
$Z_diode
UFO IR1
$I_diode
UFO VR1
$V_diode
UFO PR1
$P_diode
UFO ER1
$E_diode
