Saturn Fast Marx Module Option 2
!
! Rick Spielman 2018-11-30
!
! Screamer setup parameters
!
Time-step 4.0e-12
Resolution-time 100e-12
End-time 1.0e-6
Number-prints 5
Execute-cycles all
Grids no
Echo-setup no
Max-points 5001
!
!Start circuit definition
!
!Saturn_FM_rev5d.txt is based on Saturn_FM_rev4d.txt. We are using the exact old Saturn
! L1 dimensions and using 2 sub-Marxes. The number of stages is 16.
!
! Gas switch dimensions from drawings
!
! We have a sub Marx with 32 caps in series and 16 switches. Vch = 2.72 MV
! Each sub-Marx cap is 2, 105.44 nF caps in parallel. Sub-Marx capacitance - 6.59 nF. 
! Total Marx capacitance is 13.18 nF.
! 
! IESR is 130 m individual cap ESR / 2 in parallel X 32 half stages per = 2.08  per sub-Marx.
! Total Marx ESR is 1.04 .
!
! Assume that there will be 167 nH every stage. The sub-Marx L = 167 nH * 16 = 2.672 H.
! The total switch inductance used is 320 nH/sub-Marx. (20 nH per stage) seem low.
! The total Marx inductance is 1.336 H The total Marx switch inductance is 160 nH.
!
! Energy per sub-Marx at +/-85kV kV = 24.38 kJ
! Total Marx energy is 48.76 kJ
!
! The matched impedance of a sub-Marx = sqrt(L/C) = 20.14 .
! The matched impedance for the whole Marx is 10.07 .
!  Note, the L1 impedance is 1 .
!  The ESR amounts to ~ 10.3% of the matched impedance.
!
! The switch model will have 16x the length of one switch per sub Marx. 
! The Marx will have 2 switches in parallel.
! 
!
! L1 capacitance used is 9.15 ns/1  = 9.15 nF (C = t/Z )
!
! 
! Main Branch - Branch #1
!
BRANCH
!
! Marx capacitance and charge voltage
! two sub-Marx (6.59 each nF each)
! +/-85 kV charge
!
RCGround 1e+12 13.18e-9
Initial VC1 2.72e6

UFO VC1
$V_marx
UFO EC1
$E_marx

!
! Cap inductance, case & parasitic inductance, and ESR
! ESR = 2.08  per sub Marx or 1.04  total, Marx L from above is 1.336e-6 H - 160 nF = 1.176 F
!

RLSeries 1.04 1.176e-6

!
! Switch resistance - Martin Model and switch inductance - the total gap for both sides of a single
!   switch from DWGs is 0.53 (1.3462 cm) gap @ 93 psig air X16 = 21.5392 cm
! There are two switches in parallel
!
! Switch inductance of the Marx from above = 160 nH
! 

RLSeries 10e9 160e-9
Var R2 Switch
!dielectric switchtime gap          pressure     nswitch  nchannels
AIR           0.0               0.215      7.3                2             1

UFO IR2
$I_marx
UFO R2
$R_switch
UFO ER2
$E_switch
UFO QR2
$Q_switch

!
! Output Marx header inductance 75 nH not parallelled (WAG)
!

RLSeries 0.00 75e-9

!
! Line 1 , 9.15 ns, 1 ; 9.15 ns/1= 9.15 nF
! Include the 1.75" radius transition of the L1, 1.137 
!

TRLine EXP 1.33e-09   1.137  1.0
TRLine LIN   6.48e-09   1.0      1.0
TRLine EXP 1.33e-09   1.0      1.137

UFO VOUT
$V_L1_out
UFO IOUT
$I_L1_out
UFO EOUT
$E_L1_out
UFO POUT
$P_L1_out

!
! Impedance of the L1 output boss not included
! L1 water switches
! 10 output switches, 2.75 Saturn gap + switch inductance
! Est. arc inductance for 10 switches, 6.985-cm long (2 ns) @ Z=44  is 8.8 nH use 10 nH
!

RLSeries 10e9 10e-9
Var R2 Switch
!dielectric switchtime gap            pressure   nswitch  nchannels
H2O          270e-09     0.06985   1.0              10            1

UFO IR2
$I_L1_sw
UFO R2
$R_L1_sw
UFO ER2
$E_L1_sw
UFO QR2
$Q_L1_sw

!
! Line 2, 9.15 ns, 2  constant impedance
! Line length needs to be the same as L1 to double bounce the pulse.
! boss edge impedance 2XL1 or 2.275 
!

TRLine EXP 1.33e-09 2.275 2.0

UFO VIN
$V_L2_in
UFO IIN
$I_L2_in

TRLine LIN   6.48e-09      2.0 2.0
TRLine EXP 1.33e-09      2.0 2.275

UFO VOUT
$V_L2_out
UFO IOUT
$I_L2_out
UFO POUT
$P_L2_out
UFO EOUT
$E_L2_out

!
! L2 water switches
! 10 output switches, 0.5" gap + switch inductance
! Est. arc inductance for 10 switches, 1.27 cm long, 0.38 ns is 1.59 nH, use 2.5 nH
!

RLSeries 10e9 2.5e-9
Var R2 Switch
!dielectric switchtime    gap         pressure    nswitch  nchannels
H2O          285.0e-09     0.0127   1.0              10            1

UFO IR2
$I_L2_sw
UFO R2
$R_L2_sw
UFO ER2
$E_L2_sw
UFO QR2
$Q_L2_sw

!
! OTL, 50 ns, 2  constant impedance with L2 transitions
!

TRLine EXP 1.33e-09 2.275 2.0
TRLine LIN   50.0e-09    2.0 2.0

UFO VOUT
$V_OTL_in
UFO IOUT
$I_OTL_in
UFO POUT
$P_OTL_in
UFO EOUT
$E_OTL_in

TRLine LIN   50.0e-09    2.0 4.0
TRLine LIN   75.0e-09    4.0 4.0

UFO VOUT
$V_OTL_out
UFO IOUT
$I_OTL_out
UFO POUT
$P_OTL_out
UFO EOUT
$E_OTL_out

!
! Output resistor - 4  matched
!

RCGround 4.0   0.00

!
! End Main Branch (Branch #1)
!