A1256655817UZLeY

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FAST MARX-CHARGED ONE-STAGE MPC CONCEPT FOR
KrF LASER IFE Doug Weidenheimer Titan Pulse
Sciences Division
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Candidate Topologies Studied to Date
Efficiency Wall Plug/ E-beam (J)
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Marx-Charged 1-Stage MPC (Mag. Pulse Compressor)
- System Parameters

• Load space charge limited e-beam diode, 800 kV,
  176 kA, 600 ns.
• Vacuum Bushing 2 parallel inside-out, 72 nH
  equivalent inductance.
• Transit time Isolator T (1 way) 300 ns, water
  dielectric, 4.55 W impedance,
• stainless steel coax.
• Output Mag Switch single-turn, Lsat 110 nH,
  291 mV-sec, post-winding anneal,
• 2605SC or equivalent.
• Output Reset multi-turn, saturating.
• PFL stainless steel coax, center-charged,
  peaking section, 4.55 W (151.5 ns) -
• 4.65 W (148.5 ns) - 2.8 W (10 ns), water
  dielectric at 15oC.
• Marx erected capacitance 69.4 nF, erected
  voltage 1.6 MV, series equiv. L
• 1.76 mH, Ipk 228 kA, non-resonant inductive
  charge, laser-gated thyristor switched.
• Charging System assumed polyphase rotating
  machine at 1000 Hz or greater, 13.8 kV
• RMS class insulation, phase-controlled
  rectifier.

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System Energy Audit (kJ)
( ) with saturating inductors
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Marx-Charged 1-Stage MPC
3.5 m
10 m
10 m
Output Reset
PFL
Transit-Time Isolator
Output Switch
Marx Tank
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Fast Marx Parameters

• Erected Capacitance 69.4 nF
• Series Equivalent Inductance 1.76 mH
• Peak Current 228 kA
• Erected Voltage 1.63 - 1.64 MV
• Stored Energy 92.3 - 93.4 kJ
• Charge Transfer Time (T/2) 783 nsec
• No. of Stages 50
• Working Voltage/Stage 32.8 kV ( 16.4 kV)
• Full Stage Capacitance 3.47 mF
• Inductance per Full Stage 31.63 nH
• Stage Capacitor Configuration 2 parallel _at_
  -Vchg, 2 parallel _at_ Vchg
• Current Path Width (thru Marx) 108 cm each
  side
• Switches laser-gated thyristors ( 16.4 kV
  working)
• Inductance of Connections (ground and output)
  117 nH
• Charging inductive (non-resonant)
• Full Stage Dimensions 100 cm x 140 cm x 7 cm
• Marx Envelope Dimensions 100 cm wide x 140 cm
  high x 355 cm long

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Place holder for Marx tank vugraph -- see
workshop 2
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Full Marx Stage Schematic
Laser-Gated Thyristor
3.47mF
3.47mF
10.1nH
10.1nH
75mW
75mW
Cstray
Cstray
.50nF
1.71mW
.50nF
16.9nH
3.5pF
3.47mF
3.47mF
3.5pF
10.1nH
10.1nH
75mW
75mW
Cstray
Cstray
Ctank
Ctank
Lconn
Lconn
.56nF
.56nF
9.16nH
9.16nH
3.5pF
3.5pF
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Marx Capacitors

• Dielectric System multi-layer polypropylene
  film, impregnant
• Construction floating foil, 5 kV rated per
  section, 4 sections per winding,
• multiple windings in parallel
• Rated Voltage 20 kV
• Rated Reversal 10
• Working Voltage 16.4 kV
• Peak Current 114 kA
• RMS Current 161 Amps
• Capacitance 3.47 mF
• Energy at Working Voltage 467 Joules
• Energy Transfer Time 783 nsec
• Repetitive Service 5 pps
• Life Time 99 survival _at_ 5x108
  charge/discharge cycles
• Dimensions 42 cm x 108 cm x 3.5 cm
• Case Type welded polypropylene, buss bar
  terminals each end
• Environment oil immersion, 40oC max

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Laser Gated Thyristor Specifications

• Single Device Working Voltage 16.4 kV
• Peak Current 228 kA forward, 10 current
  reversal max
• Action 20.8 x 103 A2-sec
• Max di/dt 895 kA/msec
• Ipk /Area 4.07 kA/cm2
• Service 5 pps continuous, RCT (reverse
  conducting thyristor), 56 cm2 thyristor -
• 6 cm2 diode
• Life Time 99 survival at 5 x 108 shots
• Environment oil immersion, 40oC max
• Lasers on-board 1120 nm CWL laser diode
  mini-bars at 500 watts for 1.0 msec,
• laser duty factor 5 x 10-6
• Laser Sites 8 mini-bars/cm2 active silicon, 4
  kW optical/cm2
• Laser Drives integral with end electrodes,
  optical trigger isolation
• Silicon Device advanced fabrication
  techniques, passivation, etc.
• Full Stage Switch Dimensions 108 cm x 11 cm x
  6 cm

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Conclusion
Projections based on current component
development efforts and conformal component
packaging have shown that improvements in pulse
compressor efficiency, cost and reliability are
possible. A solid-state switched-Marx charging a
single stage magnetic pulse compressor has been
identified as a candidate topology with this
study. This approach will be investigated
further through careful modeling and benchmarking
of component characteristics and interactions.