Содержание
- 2. HINS - Purpose Robyn Madrak - FNAL APT Seminar - 12/16/2008 60 MeV Linac under construction
- 3. Unique Aspects/Challenges Solenoidal focusing ⇒ cleaner, axisymmetric beam Use of SC spoke resonators Fast ferrite phase
- 4. Robyn Madrak - FNAL APT Seminar - 12/16/2008 Parameters * full un-chopped 3 msec pulse at
- 5. FNAL HINS Robyn Madrak - FNAL APT Seminar - 12/16/2008
- 6. HINS Chopper – Part I Should the HINS be extended to an 8 GeV Linac, output
- 7. Traveling Wave Chopper Structure beam is deflected by traveling pulse (electric field) β(beam)=0.073 => must slow
- 8. Chopper in MEBT length of chopper plates: 50 cm drift space downstream: 30 cm Robyn Madrak
- 9. Deflection length of chopper plates: 50 cm drift space downstream: 30 cm plate separation: 16 mm
- 10. Pulser Development Robyn Madrak - FNAL APT Seminar - 12/16/2008 We need Two pulsers to drive
- 11. Similar Choppers CERN-SPL LANL-SNS
- 12. Combining lower voltage pulses? scope: sees ¼ of ~120V signal (25Ω/100Ω) Fet A (~60V) Fet B
- 13. Kentech 500V Pulser pulse control cards PSU pulse cards trigger and power dist cards output before
- 14. ~520 V pulse 5.5 ns 1 ms of pulses @ 53 MHz 3 ms of pulses
- 15. Pulser output 200V/div 5ns/div 3ms burst 200V/div 400μs/div 1.2 kV Pulser Nov ‘07 Robyn Madrak -
- 16. Kentech Pulsers 500 V Pulser was a success Subsequent 1.2 kV pulser was a success Plan:
- 17. Microstrips in General phase velocity and impedance are determined by effective dielectric constant: Delay time (β)
- 18. FNAL Fabricated Meanders We have pursued the following: Use double meander design with air gap between
- 19. Chopper Meanders Important Aspects Material: Outgassing ? Impedance (avoid reflections) Delay time (match beam β) Pulse
- 20. Meander Substrate Meander traces are generated by routing out traces on Rogers TMM10i, Cu clad Cheaper,
- 21. Double Meander, Impedance Impedance measurements from 1 – 500 MHz Robyn Madrak - FNAL APT Seminar
- 22. Double Meander, Delay Robyn Madrak - FNAL APT Seminar - 12/16/2008 Want β = 0.073 to
- 23. Single Meanders: Impedance and Delay Meander 1: 95 Ω @~100 MHz Meander 2: 100.5 Ω @~325
- 24. Dispersion input pulse beginning half way end single meander 2 single meander 1 “low dispersion” input
- 25. Coverage Factor The electric field between the chopper plates is less than that for a structure
- 26. Coverage Factor Measurements High frequency probe Tip is at top ground plane xy stage for position
- 27. input pulse @ end @end Coverage Factor Normalization Normalize to stripline with wide trace Use geometry
- 28. All Measured Coverage Factors Robyn Madrak - FNAL APT Seminar - 12/16/2008
- 29. Position Dependence beam RMS size 100% x Robyn Madrak - FNAL APT Seminar - 12/16/2008 20mm
- 30. 3 ms pulse combined output input 50Ω cable V1→50Ω V1→50Ω 50Ω cable MN60 ferrite: three 11’’
- 31. input ferrite 46 turns of ⅜″ superflex around five 1″ MN60 cores 1700 V →100 Ω
- 32. Heating in Meander Current in meander will be 2.4 kV/100 Ω = 24 A Need to
- 33. Chopper: Summary We have built prototypes for the necessary components for the chopper: the pulser, meander
- 34. Aside: Application of Chopper R&D to the current accelerator Initially explored the option of using a
- 35. Combining three DEI FETs from DEI/IXYS RF Use the same scheme as HINS pulser, combining three
- 36. Plates: 0.9″ spacing W1 Notching Plates in 750 keV line (H-)
- 37. In Linac after tank 2 ΔV plates = 2.9 kV ~100 ns wide notch 50 ns/div
- 38. Robyn Madrak - FNAL APT Seminar - 12/16/2008 Part II – Vector Modulators
- 39. HINS 325 MHz RF Pulse Transformer& Oil Tank IGBT Switch & Bouncer CAP BANK 10 kV
- 40. How it Works In a coaxial line filled with some dielectric (ε,μ) v = c/√εμ We
- 41. Robyn Madrak - FNAL APT Seminar - 12/16/2008 Operates in full reflection mode (end is shorted)
- 42. Modulates phase and amplitude independently: With ΔΦ = (Δφ2 - Δφ3)/2 Φ = (Δφ2 + Δφ3)/2
- 43. Two Phase Shifter Types For Cavities (~75 kW): 1.5″ OD X 0.65″ ID X 5″ long
- 44. Shifter Design Details Center conductor: shrink fit during assembly Use quarter wave matching section (for 50Ω)
- 45. Other VM Parts hybrid for 1⅝ vm: Dielectric circulator for 1⅝ vm: Ferrit-Quasar circulator load: 5kw
- 46. useful phase shift range ~120 deg. (loss Gyromagnetic resonance (lossy) @ 2.8 MHz/Oe Phase vs. Applied
- 47. Small Signal Frequency Response Open loop bandwidth: 15 kHz > 35 kHz w/feedback Response (mixer) solenoid
- 48. Slew Rate Phase Shifter Slew Rate: (above resonance) 6 deg/μs Current risetime limited by supply output,
- 49. Robyn Madrak - FNAL APT Seminar - 12/16/2008 Beam Loading - Simulation Cavity 6 Starting and
- 50. Meson Building Test Facilities 325 MHz RF Test Cage Please do not feed the animals 2.5
- 51. Meson Building Test Facilities Testing the RFQ vector modulator Testing the 1⅝″ vector modulator Robyn Madrak
- 52. Power Capabilities phase ~ (Δφ1 + Δφ2)/2 here, both shifters’ solenoids driven by one power supply
- 53. Power Capabilities 1⅝ VM for cavities: good to >75 kW Shifters alone could be used in
- 54. Vector Modulators: Summary The 1⅝″ vector modulators can operate well up to 75 kW (more than
- 55. Robyn Madrak - FNAL APT Seminar - 12/16/2008 Conclusions HINS is a key part of Fermilab’s
- 56. Backup Slides Robyn Madrak - FNAL APT Seminar - 12/16/2008
- 57. Kentech 500V Prototype Pulser Scheme 10 pulse cards: 50V→5Ω 5 FETS/card (in parallel) each FET drives
- 58. Coverage Factor, Meanders single meander signal to 500 MHz double meander (100Ω)around 100 MHz single meander
- 59. Heating in Meander Final Pulse: 2.4 kV→Z= 100Ω, 1ms@10Hz or [email protected], Chop ≤ 30% Meander Traces:
- 60. Notching Study +1.9 kV -1.9 kV Robyn Madrak - FNAL APT Seminar - 12/16/2008
- 61. Using one or two single power switches: from DEI/IXYS RF min width pulses @20MHz: 20ns/div 1ms/div
- 62. Using one or two single power switches: The DEI FETS can be used to make a
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