1. ILC Interaction Point Intra-Train Feedback Kicker November 1, 2005 Steve Smith

2. Author Name Date Slide # 2 Steve Smith - Nov ‘05 Layout/Requirements What kind of kicker and kicker driver are required for an ILC IP feedback? From the Oct. 4 BDS meeting: –Kicker ~7 m from IP –Space for kicker ~ 1m –Desire 100  capture range (IP  )  y ~ 5nm  500 nm capture range for the Y feedback  x ~ 600nm  limited to a few  capture range in X Crossing Scheme R 12 R 34 Kicker Aperture 20 mradian8.9 m3.8 m20 mm 2 mradian16.4 m4.7 m180 mm

3. Author Name Date Slide # 3 Steve Smith - Nov ‘05 Kickers Investigate two plausible solutions –Unloaded stripline kicker –Ferrite-loaded single-turn kicker. Both seem to be achievable. Many details are left out

4. Author Name Date Slide # 4 Steve Smith - Nov ‘05 Unloaded Stripline Kicker X&Y kickers can coexist in the same structure. –Assume four striplines –each stripline covers 20% of the circumference. Electric field at the center: E 0 ~ 90%V strip /R Y kick: angle of  ~ 500nm/3.8m = 130 nanoradian kick. At p = 250Gev/c  160 V max each stripline (20mr crossing)  1400 V max (2 mr crossing) Strip impedance ~50 Ohms,  ~500W peak (20 mr)  ~35 kW peak ! (2 mr) For lower stripline Z impedance, the current & power go up. These drive requirement can be met. –Example: MOSFET driver proposed for the damping ring kickers requires 5 times the drive voltage and 100 times faster risetime But at the kV levels one should think of ferrite-loaded kickers to reduce the drive requirements.

5. Author Name Date Slide # 5 Steve Smith - Nov ‘05 Ferrite Kicker Y and X kickers no longer coexisist –must be at different z’s. The model for a kicker is a single-turn ferrite loaded kicker. Assume a drive impedance of 12.5 Ohms. –(without design or calculation) Use formulas for inductance and field that are appropriate for low gap height-to-width then apply to a kicker with h~w so take the details with grains of salt. Needs a kicker designer

6. Author Name Date Slide # 6 Steve Smith - Nov ‘05 20 mr Crossing Scheme Kicker ParameterValue Length1 m Turns1 Gap height20 mm Gap width40 mm Impedance25 Ohms Max kick±130 nradians ParameterValue Current2 Amps Voltage43 Volts Power75 Watt Inductance2.5  H Rise time100 ns (L/Z)

7. Author Name Date Slide # 7 Steve Smith - Nov ‘05 2 mr Crossing Scheme Kicker ParameterValue Length1 m Turns1 Gap height180 mm Gap width180 mm Impedance12.5 Ohms Max kick±100 nradians ParameterValue Current13 Amps Voltage300 Volts Power4 kW Inductance1.3  H Rise time100 ns (L/Z)

8. Author Name Date Slide # 8 Steve Smith - Nov ‘05 Mathcad Calculation

9. Author Name Date Slide # 9 Steve Smith - Nov ‘05 Further simplification 300 ns is lots of time Forget matched transmission line Drive kicker as a shorted inductor.

10. Author Name Date Slide # 10 Steve Smith - Nov ‘05 X Feedback Cannot deflect beam by q = 60  m/10 m = 6 microradians in X. Can the capture range be reduced? Propose limiting x kick to a few times that of y kicker e.g. a few microns Get some help from ratio of R 12 /R 34 ~ 2-3 Use the same kicker design