1. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC L0-1 Electrical and Mechanical Tolerances John Schmerge, SLAC November 3, 2004 SLAC 3 m Linac RF Couplers Field Perturbation in Amplitude and Phase RF kick from single feed SLAC Linac Dual feed tolerance criteria Dual Feed Tolerances Coupler hole position Couple hole size Dual feed RF amplitude asymmetry Dual feed RF phase asymmetry Summary

2. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Field Perturbation 2a = aperture ≈ 2 cm d = cavity length = 3.5 cm  t = pulselength = 10 ps  E 1 /E z0 = 10%  = 1.5˚

3. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Time Dependent Kick from RF Couplers SLAC Linac Coupler Cell E-beam RF Coupler Normal Cell Coupler Cell  E 1 /E z0 Coupler cell offset away from coupler to compensate kick due to amplitude term (  E 1 /E z0 = 0.1% ). But phase term uncompensated (  = 1.5˚). 2a diameter aperture SLAC Linac Non-coupler Cells

4. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Kick at Entrance of L0-1 Uncompensated  E 1 /E z0 = 10%  = 1.5˚ Compensated  E 1 /E z0 = 0.1%  = 1.5˚

5. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Mechanical and Electrical Tolerance Criteria Dual feed must reduce  E 1 /E z0 by at least a factor of 100 or it is less effective than a standard SLAC compensated structure. Dual feed required to reduce  by a factor of 10. Racetrack required to reduce  E 2 /E z0 by a factor of 10. (Tolerance computed from simulation)

6. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Coupling Hole Position Tolerance Phase term -  < 11 ° Amplitude term -  < 1.1 °

7. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Coupling Hole Size Tolerance Phase term –  D/D 0 < 0.2Amplitude term -  D/D 0 < 0.02

8. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Dual Feed Amplitude Tolerance Amplitude term –  V/V 0 < 0.02

9. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Dual Feed Phase Tolerance Phase term -  < 3 ° Amplitude term -  < 4.4 °

10. Injector RF Design Review schmerge@slac.stanford.edu November 3, 2004 John Schmerge, SLAC Summary Dual Feed Mechanical and Electrical Tolerances Studied for 4 cases: Coupler position error Coupler iris size error RF feed amplitude error RF feed phase error