Leonardo Ristori

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Proton Driver Front EndRoom Temperature
Crossbar H-Type (RTCH) Cavities Design and
drawings package update
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Overview of cavities
All 16 Cavities are different in length and radius
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Views Sections of RTCH 1 (ß0.0744)
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Components
OFECu Cylinder
OFECu Bases (4)
OFECu Spokes (3-4)
Cu Cooling tubes
OFECu End wall Drift Tube
SST-OFECu 2layer End wall
Cu plated SST Vacuum Grid
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Connections
RF Coupler Flange 3 ½ CF
Tuners Flanges 2 ½ CF
Cooling System ID Ø1/3 8mm
Solenoid Connection 2 NW40 Seal
Probe Flange 1 1/3 CF
Vacuum Flange 3 ½ CF
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Design update
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End wall design improvement

• Double layer wall to eliminate RF Cu wall
  deformations
• 3mm OFE Cu wall inside, 5mm SST wall outside
• Overall thickness of wall is 10mm (same as former
  design)
• 2mm gap between walls. Under vacuum, outside wall
  deforms lt1mm
• Two options for mounting
• Assemble SST-Cu walls together and braze to
  cavity
• Braze Cu wall on cavity first and Braze SST wall
  on cavity after eventual RF wall and DT
  corrections made

Previous design
Def940µm
smax120MPa
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Cylinder design modified

• Due to temperature gradient, spokes expand more
  than cylinder
• Thinner cylinder deforms more to release stress
  on drift tubes (15)
• Deformations of cylinder are still under
  acceptable limits

Tmax34C
smax38.3 MPa
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Drawings Package update

• From
• Providing not many drawings of finished cavity
  considered as a single part
• Risk of permanent contacts with all vendors
• To
• Providing more self-explanatory package where
  every obvious operation is specified (i.e.
  welding, brazing, )
• Some options are still left to vendors

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Drawings package outline
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Full Assembly Drawing
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Brazing Assembly Drawing
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Simple brazing features
Cylinder Part drawing
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Base Part drawing
Brazing option
Spoke Part drawing
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Tuner Port Part drawing
Probe Port Part drawing
RF Port Part drawing
Vacuum Port Part drawing
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End wall Assembly Drawing
Update in progress
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Update in progress
End wall Part drawing
Drift Tube Part drawing
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Tubes Part drawing
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Notes on fabrication of Spokes

• Spokes will have the highest surface quality
  compared to the other cavity elements
• Higher losses
• Train vendor
• Option of fabricating in 3 brazed parts is left
  open to vendors (option is specified anyways)
• Spokes in cavities with bigger beta may require
  reinforced drift tubes (Cu plated SST is an
  option)

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Longitudinal dimensions
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3 4 Spokes Transition