KEK/ISIS/ANL LOI Amplifier/Second Harmonic RF Collaboration Meeting

Tuesday, 26th of June, 2007

PAC07, Albuquerque, NM

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IPNS RCS RF System Block Diagram:

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Third Cavity Installed in L6 Straight Section:

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Third Cavity and Final Amplifier:

Final amplifier uses two Eimac 3CW150000H3 water-cooled power triodes in a grounded-grid, cathode-driven, push-pull topology.• Operated Class A.• Plate power supplied by an 8 kV, 24 A DC power supply.• Typical operating point:

•Vplate = 8 kVDC•Vgrid = -320 VDC• Zero-signal plate current/tube ~ 5 A

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Final Plate Supply: 8 kV, 24 A DC Cavity Bias Supply: 0 to 1000 A DC

Final Grid and Filament Cabinet

Final Plate Supply, Cavity Bias Supply and Filament and Grid Supply Cabinet:

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Predriver and Driver Amplifiers:

Predriver amplifier uses two Eimac YU-106 water-cooled power triodes in a grounded-grid, cathode-driven, push-pull topology.• Operated Class A.• Plate power supplied by a 5 kV, 4 A DC power supply.• Typical operating point:

• Vplate= 5 kVDC• Vgrid = +35 VDC• Zero-signal plate current/tube ~ 1 A

Driver amplifier uses two Eimac 4CW25000A water-cooled power tetrodes in a grid-driven, push-pull topology. • Operated Class A.• Plate power supplied by a 5 kV, 10 A DC power supply.• Typical operating point:

• Vplate = 5 kVDC• Vscreen = 1.5 kVDC • Vgrid = -300 VDC• Zero plate current/tube ~ 3 A

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Timeline:• Summer Shutdown, 2005: Disassembled test stand and moved equipment into place.

• Winter Shutdown, 2005-2006: Installed third cavity in RCS.

• March, 2006: Operated all three cavities with beam (3rd cavity operated in fundamental mode).

• Septemember, 2006: Operated 3rd cavity in second harmonic mode (for first ~4ms of cycle) with beam.

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3 2 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 170

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Fundamental Rectified Gap VoltageSecond Harmonic Recitified Gap Voltage

Cycle Time (ms)

Rec

tifie

d G

ap V

olta

ge (

kV)

Vfi

V2fi

T i( )

0 90 180 270 3601.5

1

0.5

0

0.5

1

1.5

Fundamental Gap VoltageSecond Harmonic Gap VoltageTotal Vector Sum Gap Voltage

Degrees

Volta

ge (R

elat

ive

Uni

ts) Vf

t

V2ft

VTotalt

t

Time

Injection

Mountain range plot starting at injection without second harmonic, duration ~4 ms.

Mountain range plot starting at injection with second harmonic, duration ~4 ms.

Bunch profile without second harmonic, at ~1.8 ms after injection. Bunch profile with second harmonic, at ~1.8 ms after injection.

Rectified fundamental and second harmonic gap voltage. Single-turn, vector sum of gap voltages, at ~1.8 ms after injection.

Results with Second Harmonic:

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Future Plans: