Background on Klystron

1
Background on Klystron

• Prior NLC Requirement Was 75 MW, 1525 ns Pulse,
  120 Hz
• Demonstrated to Date 75 MW, 2820 ns, 1 Hz
• New NLC Requirement is 75 MW, 3168 ns, 120 Hz
• This Device is Well-Beyond the State of the Art
• Equivalent to 5045 (SLC Klystron) Delivering gt
  700 MW
• Status of Prototype Tubes
• First Tube on Bakeout Prelim Test Data in
  Mid-November
• Second Tube to Bakeout at End of November
• Consequences
• Some of the Interface Requirements May Need to
  Change

2
Klystron Interface Requirements1 of 3

• Draft Specification Released (9/21/01)
• Fit
• Outline Drawing Not Yet Available
• Stay-Clears Provided to Modulator and RF
  Compression Groups
• Operating Orientation Specified (Vertical,
  Cathode Down)
• Mating Connections
• RF Flanges
• Input is WR90 Instrument Flange
• Output is High Power WR90 Flange 5 x 10-8 Torr
  Pressure
• Modulator Socket Information (AMP P/N 19227)
  Specified
• All Water Fittings Specified (Hansen)
• Thermocouple Fittings Specified (Type T)
• Thermistors Specified (MS3120E-6S)
• Ion Pump Connections (Standard Varian 8-Liter)

3
Klystron Interface Requirements2 of 3

• Pulsed DC Power Requirements Defined (Nominal)
• Beam Power of 490 KV, 257 Amps
• Maximum Inverse Voltage 50 kV
• Heater Power of 25 V, 25 Amps DC
• Maximum Heater Inrush Current of 50 Amps
• Heater Timeout on Warm-Up of 60 Minutes
• Magnetic Field Trim Coils (3 Each)
• Water Cooling Requirements
• Collector 20 GPM at 120 PSI
• Body, Anode, and Coils 10 GPM at 120 PSI
• Window and Waveguide 5 GPM at 120 PSI
• Magnet Stack 2 GPM at 120 PSI
• Water Supply Temperature
• 25 C for Magnets 35 C for Everything Else

4
Klystron Interface Requirements3 of 3

• Safety/Mechanical
• Tube Plus Integral Lead Shielding Weighs 682 kg
• Cathode End of Tube Must be Submerged in De-Aired
  Water-Free Transformer Oil Covering the Upper
  Corona Ring
• Radiation 5mR per Hour at 30 cm
• RF Radiation 1 mW/cm2 at 1 cm
• Tube Collector Un-Grounded for Current Monitoring
  Purposes
• Earthquake Restraint Pending Tank/Area Design
  Details
• Other
• Extra Water Chiller for Magnet Water Needs to be
  Included in Planning

5
Klystron Plans

• Obtain Feedback on First Two Tubes (Electrical
  Test)
• CPI Tube Has Differences from SLAC Design
• Decision on Next Tube Contingent on Testing
• Rebuild One or Both Tubes with Needed Changes
• Fabricate Third Tube Earliest Possible Date to
  Bakeout is End of CY01.
• No Other Tubes Possible Without More Parts

6
Background on TWTA

• Very Low Average Power at X-Band Unusual No
  Existing Products
• Normal Concerns/Issues Do Not Apply
• Cost and Reliability Paramount (Long-Term)
• Many Existing TWTAs are Sub-Spec EW Devices
  Not Designed for This Application
• Four-Pack/Eight-Pack TWTA Design
• TWT and Power Supply from SBIR Project
• Designed for Cost and Reliability

7
TWTA Interface Requirements

• Prime Power 110 VAC, 2 Amps
• Size Standard 19 Rack, Four Units High
• Weight 10 kg
• Input RF Connection Type N Coaxial
• Input RF Power 5 dBm at TWTA Input
• Output RF Connection Type N Coaxial
• Output RF Power 60 dBm at TWTA Output
• Cooling Ambient Air, 30 C

8
TWTA Plans

• Monitor Phase II SBIR
• Tube Supplier is Prime
• Power Supply Provided Under Subcontract
• Place Order for Four TWTAs in January, 2002