J. Pozimski-FETS Meeting @ IC 10 May 2006 First experiences with the FETS pepperpot detector.
324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.
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Transcript of 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.
![Page 1: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/1.jpg)
324MHz FETS RFQ RF measurement and components
By
Aaron Cheng
18 December 2006
![Page 2: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/2.jpg)
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Overview
1. Bead-pull measurement 2. RF coupler preliminary design approach
![Page 3: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/3.jpg)
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Bead pull measurements
ISIS copper cold model in Imperial College
![Page 4: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/4.jpg)
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Bead pull measurements
Bead pull results on ISIS copper cold model
![Page 5: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/5.jpg)
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Bead pull measurements
Bead pull results on ISIS copper cold model
![Page 6: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/6.jpg)
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Bead pull measurements
LabVIEW beadpull measurement control program
![Page 7: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/7.jpg)
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•Presentation on ‘High Power RF couplers’ by James Rogers in ASTeC
•Investigate on coax structure to match 50ohm impedance @ 324MHz
•investigate waveguide-to-coax transition
•RF energy transferred from klystron to RFQ via waveguide, waveguide-coax transition, RF window and RF input coupler.
•@ waveguide-coax transition structure, coupling @ lowest mode TE101
•Study klystron output waveguide-coax transition structure (magnetic field coupling); Current waveguide size is WR2300
•Implementing a doorknob structure (electric field coupling)
RF coupler preliminary design approach
![Page 8: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/8.jpg)
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RF coupler preliminary design approach
•Coax matching.
•Outer diameter of insulation fixed @ 40mm (KF flange size on RFQ), modelled as vacuum
•Optimized conductor to obtain 50ohm match inner diameter = 17.4mm
![Page 9: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/9.jpg)
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RF coupler preliminary design approach
•Studying klystron o/p T-struc wg-coax
•Coupler varied in distance from waveguide end-plate and in height
S11 = -3.32dB S21 = -2.589dB
![Page 10: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/10.jpg)
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RF coupler preliminary design approach
•Studying doorknob wg-coax
•Increased wg length
•Coupler varied in distance from waveguide end-plate and in height
S11 = -22.59dB S21 = -0.717dB
![Page 11: 324MHz FETS RFQ RF measurement and components By Aaron Cheng 18 December 2006.](https://reader036.fdocuments.in/reader036/viewer/2022062715/56649dac5503460f94a9bc5b/html5/thumbnails/11.jpg)
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Summary
1. Bead pull measurement almost ready to go. Other issues are finding suitable bead
2. Waveguide-Coax transition design started and on-going. Current status:
• Electric field probing show promising results
• Investigate into half-height wg, different T-shape geometry, conductor with cooling pipes etc.
3. Other tasks:
• Microwave signal generator and amplifier in the process of purchasing:
• Delivers 20W-50W to drive klystron and RF control purposes