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Linac RF Source. Recommendations for Items 22,23,24,46,47. Chris Adolphsen. Modulators (115 kV, 135 A, 1.5 ms, 5 Hz). Baseline Choice: DESY/FNAL Pulse Transformer - PowerPoint PPT Presentation

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  • Linac RF SourceRecommendations for Items 22,23,24,46,47Chris Adolphsen

  • Modulators (115 kV, 135 A, 1.5 ms, 5 Hz)Baseline Choice: DESY/FNAL Pulse TransformerPros: Seven units built by industry - no major reliability problems. Choice for the XFEL: DESY continuing to work with industry on improvements. FNAL working on a more cost efficient and compact design.Cons: Susceptible to single-point failures, large oil-filled transformer (in tunnel for single tunnel design), high labor cost to assemble.

    Alternate Choice: Marx GeneratorPros: Solid state, 1/n redundant modular design for inherent high availability and reliability. No transformer, air cooled. Highly repetitive IGBT modules, cheap to manufacture: may be up to 50% less expensive.Cons: No working model - first prototype in 2006. Need to develop long-haul 115 kV transmission line if have clustered rf sources.

  • KlystronsBaseline Choice: 10 MW Multi-Beam Klystrons Only high power, high efficiency tube available (two Thales tubes have achieved full spec after gun fix, only few hundred hours operation at 10 MW).

  • Alternatives to be Considered(Long development time, no funding in 2006)10 MW Sheet BeamKlystron (SBK)Parameters similar to10 MW MBKLow Voltage10 MW MBKVoltage e.g. 65 kVCurrent 238AMore beams

    Perhaps use a Direct Switch Modulator5 MW Inductive Output Tube (IOT)DriveOutputIOTKlystronSLACCPIKEK

  • RF Components per LinacAverage cryomodule gradient = 31.5 MV/mOverhead for BNS and failed units = 5%Number of cavities (ignoring BC, Undulator) 1.05*(250-5)/(0.0315*1.038) = 7868Number of 8-cavity cryomodules = 984Number of 10 MW rf stations = 328Beam Power / RF Power Capability 245 GeV * 9.5 mA / (328 * 10 MW) = 71%

  • RF Distribution Math(for 35 MV/m Max Operation)35 MV/m * 9.5 mA * 1.038 m = 345 kW (Cavity Input Power)24 Cavities1/.93 (Distribution Losses)1/.89 (Tuning Overhead)10.0 MW10 MW Klystron