ILC Marx ModulatorILC Marx Modulator

Development Program Development Program

G.E. Leyh, Stanford Linear Accelerator CenterG.E. Leyh, Stanford Linear Accelerator Center

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

ILC Modulator RequirementsILC Modulator Requirements

120 kV

140 A

1370 uS

192 mC

23,520 J

5 Hz

125 kW

576

Klystron Pulse Voltage

Klystron Pulse Current

Pulse Length [flat-top]

Total Pulse Charge

Total Pulse Energy

Repetition Rate

Average AC Input Power

Total # of Stations

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Baseline 10MW TTF ModulatorBaseline 10MW TTF ModulatorDeveloped in the early 90’s at Developed in the early 90’s at FermiLab for use with the TTF.FermiLab for use with the TTF.

Currently in use at FNAL and Currently in use at FNAL and on the XFEL at DESY.on the XFEL at DESY.

Uses a passive ‘bouncer’ Uses a passive ‘bouncer’ circuit to compensate for circuit to compensate for capacitor droop.capacitor droop.

Advantages:Advantages: Simple circuit topologySimple circuit topology Proven design; 10+ years of operationProven design; 10+ years of operation

Disadvantages:Disadvantages: Mechanically complexMechanically complex Massive pulse transformer – 6.5 tonsMassive pulse transformer – 6.5 tonsRequires large floor areaRequires large floor area Insulating oil – 100’s of gallonsInsulating oil – 100’s of gallons

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

ILC Marx Modulator LayoutILC Marx Modulator Layout

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Marx Advantages – EfficiencyMarx Advantages – Efficiency Much lower switch currents (140A vs >1600A)

Switches operate only once per pulse Highest efficiency – avoids switching losses Improves reliability – switching events are high risk

No core losses or reset circuitry

Higher waveform efficiency

96-98% stack efficiency, based on measurements of switch losses under full pulse width and current

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Marx Advantages – Site Installation Marx Advantages – Site Installation CostsCosts

Compact size – requires 1/3 the floor space

No oil required Saves 100’s of gallons per modulator Avoids safety and environmental issues

Simplified modulator enclosure requirements

Modular construction improves tunnel transport

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Marx Advantages – Modular Marx Advantages – Modular DesignDesign

Increased availability Marx Stack can work around failures Modular Design reduces MTTR

Allows printed-circuit integration Greatly reduces assembly costs Streamlines QC processes

Reduces inventory of spare components

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Schematic – Marx StackSchematic – Marx Stack

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Minimizing Voltage Overshoot by Staggering Prompt Minimizing Voltage Overshoot by Staggering Prompt CellsCells

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

12kV Solid-State IGBT Switch12kV Solid-State IGBT Switch

5-section modular PC-5-section modular PC-board design, using board design, using 4500V Single-Die IGBTs4500V Single-Die IGBTs

Each section has Each section has independent gate drivers, independent gate drivers, delay stabilization delay stabilization circuitry, overvoltage circuitry, overvoltage protection and snubbing protection and snubbing networksnetworks

Switch designed to Switch designed to operate at full spec with operate at full spec with one failed sectionone failed section

Overcurrent protection Overcurrent protection with multiple with multiple threshold/delay setpointsthreshold/delay setpoints

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

12kV Marx Cell on Test Stand12kV Marx Cell on Test Stand

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Sparkdown Test Waveform Sparkdown Test Waveform Response to Hard Fault at CellResponse to Hard Fault at Cell

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Modulator Test ChamberModulator Test Chamber

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

Timing Control for Ground Timing Control for Ground StationStation

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

End Shield, 1End Shield, 1stst two Test two Test PositionsPositions

G.E. LeyhG.E. Leyh ILC Marx Prototype DevelopmentILC Marx Prototype Development 25 August 200625 August 2006

PRIME POWER – ONE-LINE DIAGRAM