LINAC LOW ENERGY MODULATORS status update
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Transcript of LINAC LOW ENERGY MODULATORS status update
LINAC LOW ENERGY MODULATORSSTATUS UPDATE
FERMILAB DESIGNHowie Pfeffer/Jim Biggs
12/19/12
FERMILAB SPECS
SOME OF THE TOUGH SPECS:Beam Top Tilt (Adj.): +/- 5 kVBeam Voltage Step SR: 15 kV/usecFlattop/Beam Regulation: +/- 25 VRepeatability: +/- 10 VMaximum spark Energy: < 5 Joules
SOME SPECSPulse rep rate: 15 HzMaximum Output: 35 kVLoad ~100 ohmRise time (Adjustable): 150 usecFall time (Adjustable): 150 usecFlat top time (Adjustable): 160 usecBeam Length/Time (Adj.): 110 usecMaximum step size: 1.5 Kv
Essentially a 35kV, 350 amp, OPAMPCapable of 15 kV/usec slew rate
BLOCK DIAGRAM OF PROPOSAL
MARX PS BLOCK DIAGRAM
BASIC TEST CIRCUIT
SnubberCurrent GenerationCircuit
BASIC TEST CIRCUIT
CURRENT WITH STEP
Current
IGBT 40U.5.6UHI DIRECTCurrent
Collector Volt
Emitter Volt
SNUBBER CAPACITOR MOUNTING
SHORT CIRCUIT DURING TURN ON TEST CIRCUIT
900 VOLT – GATE VOLTAGE
Collector Volt
Gate Volt
Gate Control
CT1 Current
900 VOLT, 20 USEC
Collector Volt
Gate Volt
CT1 Current
CT2 Current
SHORT DURING PULSE TEST CIRCUIT
CONCLUSIONS IGBT Switching action has been
confirmed with acceptable transient voltages.
IGBT short circuit current limiting and safe turn-off have been confirmed for turning on into a short and “spark-type” short circuits.
Design for a 10 stage pulser is complete.
FUTURE PLANS Starting to specify and order parts for
10-stage Expect to have parts ordered by end of
January Parts should be here in 3 months Begin mechanical design and layout
beginning of February.