High Power RF Systems, Control andDistribution in the HINS
Alfred Moretti, Brian Chase, Chris Jensen andPeter Prieto
Fermilab Accelerator Advisory Committee
May 10th – 12th , 2006
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Outline
•Genera description of Fermilab High IntensityNeutrino Source (HINS) Linac
•Description of (HINS) linac R&D Study.
• Conclusions.
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325 MHz Klystron – Toshiba E3740 FERMI
115kV Pulse Transformer
Modulator Capacitor
/ Switch / Bouncer
Charging
Supply
RFQ
MEBT
RF
Distribution
Waveguide with
Dir Couplers
Ferrite
Tuners
Single Klystron FeedsRT and SCRF Linac
to E > 90 MeV
HINS 325 MHz Front END
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M
325 MHz RF System
PulseTransformer& Oil Tank
IGBTSwitch &Bouncer
CAP
BANK
10 kV
110 kV
Charging
Supply
300kW
MODULATOR: FNAL/TTF Reconfigurable for 1,2 or 3 msec beam pulse
Single
Fermi
Klystron
325MHz
2.5 MW
WR2300 Distribution Waveguide
TOSHIBA E3740A
I
Q
M
E
I
Q
M
B
I
Q
M
T
I
Q
M
R F Q
I
Q
M
Cables to
Tunnel
Fast Ferrite
Isolated I/QModulators
RF Couplers
S
I
Q
M
S
I
Q
M
R
I
Q
M
S
I
Q
M
S
I
Q
M
R
I
Q
M
400kW
20 kW
D
I
Q
M
S
I
Q
M
R
I
Q
M
D
I
Q
M
S
I
Q
M
R
I
Q
M
120 kW
10kV
H-
Medium Energy
Beam Transport
Copper Cavities
RadioFrequency
Quadrupole
RT Copper Single-Spoke
Resonators
Cryomodule #2Double-Spoke
Resonators
20 kW
There will be more power distribution splits than shown
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Simplified Layout of the RF Fan-out for 8 GeV HINS Linac
This is simplified Layout of the high power RF distribution system
• The 325 MHz high power line is as shown except it will have 3 power splitterfor Powering 3 directional coupler Arms and the RFQ.
• The 1300 MHz high power line because the base line klystron has two5 MW power output Lines will have two 5 MW branches with several powersplitters in each powering directional coupler arms.
Directional Couplers
Ding Sun’sTalk
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Key: Klystron-- , Hybrid-- , Load-- , Cavity--
Penetrations
Linac Tunnel
Linac Gallery
One 325 MHz Klystron Driving 58 Cavities and RFQ
H
H
H
RFQ
1 -- - - - - ---- 18 Rm temp
19 - - - - - - - - - - - -- - - - - - - ---- - -39 Super C
40 - - - - - - - - - - - - - -- - --- - -- ---- - - 58 Super C
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Status of Required Components
•Vendor quotes have been received for therequired hybrid power splitters.
•Vendor quotes have been received for thestring of directional couplers required toprovide RF power to the cavities.
•In-house studies of directional coupler stringsusing HFSS is underway.
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Directional Coupling Factors along the 325MHz section of the HINS Linac
•The chart shows that theSuperconducting cavitycoupling factors remainconstant with changes in beamloading (Blue and Yellowcurves).
•The red and black curves showthe coupling factor change withbeam loading with beamloading changes.
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HINS 325 MHz Klystron
Toshiba E3740AFermi
325 MHz 2.5 MW
Specifications:
Beam V= 98 kV
Beam I= 51 A
Perveance=1.75uP
Gain= 47 dB
Efficiency=50 %
Modulating Anodegrounded to make adiode tube.
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325 MHz kltsron in Meson Building on its wheels.
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325 MHz Components
Circulator
ModernPhoto-multiplier forArc detection
Miscellaneous requiredRF Components:Bends, Couplers,Bellows, straightpieces,etc.
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LAYOUT OF Test and HINS Area
LL RF Input
Klystron
Circulator
Load
Switch
Waveguide components,bends, straights, couplers, etc.,to Experimental test area
Waveguide Componentsto HINS Area,
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Bouncer Modulator Circuit
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Bouncer Modulator Waveforms
•Switch connects main capacitorbank to transformer duringpulse.
•Transformer steps up voltageto 120kV/130A (12:1)
•Main capacitor bankdischarges by 20% duringpulse
•“Bouncer” circuit compensatesfor cap bank droop.
Main Capacitor and Bouncer Capacitor Voltage
Klystron Voltage and Expanded Klystron Voltage
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Pulse Transformer 4 ms Pulse Length for HINS
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System Control
Forward/Reflected Power
Photo Detector
Video Pulse
Klystron Protection Interlock Boards
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HINS and SMFT Interlocks
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Conclusions
•All of the components for the 325 MHz klystron outputRF power testing are on-hand. First RF power testing of325 MHz klystron is scheduled for July of this year.
•Major Components of the modulator are on hand andtesting of major assemblies is underway.
•Design of the of the equipment and safety interlocks hasbeen completed. Construction and assembly and testing ofthe boards are underway.
•Conceptual design of the low level RF system has startedin collaboration with LBL . Adaptations of In-house,Desy and SNS prototype control boards are under study .