Klystrons and RF Feed

1
Klystrons and RF Feed

• A. Moretti
• March 15 , 2005

2
Outline

• Klystrons for the Proton Driver
• 325 MHz RF Distribution Layout and description
• 1300 MHz RF Distribution Layout and description
• Conclusion

3
Layout of 0.5 MW Initial Linac
4
Klystrons

• The 8 GeV Linac uses 12 Klystrons of 2 Types
• 325 MHz JPARC Klystron (1-2 required for front
  end)
• 1300 MHz TESLA Multi-Beam Klystron (11 required)
• Both types are now Catalog Items

5
Toshiba E374A High Power Amplifier Klystron
Tube is designed for particle Accelerators Tube
tunable to 325 MHz Tube is in production for
J-Parc 17 tubes have recently been
delivered to J-Parc. Power Output 3.0 MW
Gain 50 dB
Efficiency 55 Duty Factor 2.6

Toshiba has verified to us that tube can meet
Baseline Specification of 4.5 ms at 2.5 Hz
and future requirement of 1.5 m.s 10 Hz
6
MBK Three Klystron Vendors

• Thales Prototype in operation at DESY for
  18,000s hrs., 2 sent back because
• of gun sparks-3000 hrs
  They have been modified and corrected, sent
• back, met Spec at factory
  and no hint of problem at DESY. DESY has
• ordered 8 more tubes.
  Cathode emission loading high compared to
• other vendors predicted life
  of 40,000 hrs.
• Looking at different
  dispenser Cathode materials for longer life.
• CPI One tube has been shipped to DESY,
  Testing limited to 9 MW full
• duty because of limitation
  factory PS, 58 efficiency measured,
• study underway to increase
  efficiency, cathode Loading for long
• life is low, tube has large
  Diameter.  
• Toshiba RD phase has been tested to 10.3 MW , 1
  ms at 10 Hz needs PS
• modification full pulse
  flattop length, low cathode Loading for long
  life.

7
Multi Beam Klystron THALES TH1801
Thales has verified to us that tube can meet
Baseline Specification of 4.5 ms at 2.5 Hz and
future requirement of 1.5 m.s 10 Hz.
8
CPI VKL-8301 MBK
9
Toshiba E3736 MBK
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Klystron Pulse Width

• The Initial Proton Driver scenario requires a
  4.5 msec RF pulse (3 msec beam pulse) at 2.5 Hz
• Both Klystron manufacturers will deliver tubes to
  this pulse width, but cannot test this at the
  factory.
• The 4.5 msec modulator being built for PD at SMTF
  will be used for this test.

11
1300 MHz RF Fanout

• Fanout is nearly a copy of 361 TESLA RF fanout
• Phase shifters used below 2 GeV
• Components rated to handle Ultimate beam power

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RF distribution 1300 MHz (Typical)

• 
  
  LL RF Drive
  Signal Input
  
  
• 
  10 MW Klystron
• 
  
  
  
  
  
• 
  Hybrid
  Coupler
  
  
  
  
• Circulator
• Load
• 
  
• 
  
• 
  
• 
  
• 
  
• 
  

Only used in the RD Phase
IQM Ferrite modulator




Phase Amplitude
One of 18 Cavities in Cryo Module
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325 MHz RF System
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RF Distribution 325 MHz (Typical)
Only used in the RD Phase
Hybrid Coupler
325MHz Klystron
Circulator
Load
IQM Ferrite Modulator




Phase Amplitude

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• 
  
  
  
  
• 
  
• 
  
  
• 
  
  
  
  
• 
  
  
• 
  
• 
  
• 
  
• 
  

Cavity
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Waveguide components near 1300 MHz Klystron at A0
Typical Components 5 MW at Output of the A0 High
Power Klystron Right Angle Bend
Straight Piece Flex Section
Directional Coupler

16
Typical Waveguide 1300MHz in A0
1300 MHz Coaxial Load Waveguide
Load 4 port Circulator 325 MHz
Components Available many Vendors.

17
High Power Components 1300 325 MHz

• 5 MW Circulator Many vendors, Not used in the
  XFEL design
• More Vendors Available for lower Power
  Circulators.
• Hybrid Coupler Many vendors available High and
  low power, may require optimization for better
  specs in VSWR, etc.
• Loads Many vendors available High and low power.
• Other components Many vendors available High and
  low power.
• IQM Vendor delivery in 2 months, High power,
  1300 MHz.
• In House High and Low power _at_
  1300 325 MHz.

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CONCLUSIONS

• Components are commercially available from many
  Vendors to meet our requirements in a timely
  manner to complete the system as designed.
• The only new component, the IQM for Phase and
  Amplitude control, is being developed both
  In-House Commercially. (see Terechkines talk)
• The SMTF is a test bed for all the components and
  system will be used to test all components and
  qualify Vendors.