1. Plan for Beam Extraction using strip-line kicker with pulse bump orbit Present extraction kicker system Strip-line kicker system for ILC Beam extraction using strip-line kicker at ATF Preliminary test Magnets and power supplies for pulse bump Experiment plan T.Naito

2. Present beam extraction (Pulse magnet kicker system) Kick angle Stability 1x10 -3 -> 2.8x10 -4 3 bunches, 154ns spacing 308ns pulse width The number of bunches are limited.

3. Strip-line kicker system for ILC ~20 units for 0.6mrad kick angle

4. Design of Strip-line electrode for ILC The shape of the electrode is designed to keep good uniformity of the deflecting field. The calculated flatness is 0.07% in the area of +/- 1.8mm from the center. Max field 2.0MV/m 1.27MV/m Geometric factor(analytical) =0.955

5. FID FPG5-3000M(1) Burst pulses(3MHz, 3000pulses) droop : ~3% Single pulse waveform

6. FID FPG5-3000M(2) Pulse width(FWHM) = 2ns Pulse height = 5.8kV Rise time = 1.5ns(5%~95%) Time jitter = 29ps Amplitude jitter = 0.72% (limited by the scope resolution) Timing jitter measurement 29ps(1s) Amplitude jitter measurement 0.72%(1s)

7. Beam kick experiment at ATF-DR Single unit of strip-line kicker The kick effect of the single strip-line kicker was measured by measuring the amplitude of the betatron oscillation in the ring. A turn-by-turn BPM system was used for the measurement of the betatron oscillation.

8. Timing scan of the kick pulse Rise time = 3.2ns (1%~100%) Fall time = 4.0ns (100%~1%) Beam kick profile measurement The timing of the kick pulse is scanned for the timing of the beam with 200ps steps. The kick angle is estimated from the amplitude of the betatron frequency of the FFT signal.

9. Location of strip-line kicker Strip-line kicker The bunch spacing in extraction line does not completely the same interval. A 2.8ns( or 5.6 ns) is added at every three bunches, for example, 154ns, 154ns, 154ns, 156.8ns, 154ns.... The extraction pulse magnet is replaced by two units of strip-line kickers. Three cycles of the injected beam, which include up to 60 bunches, are extracted bunch-by-bunch with 154ns (or 308ns) spacing.

10. Strip-line electrode and pulser for ATF beam extraction Electrode distance:12mm Chamber diameter : 24mm Impedance :50ohm Max field at 10kV : 4.7MV/m FID developed 6MHz burst, 7kV peak pulser.

11. A 60cm long kicker magnet makes a 4.6mrad kick angle. Two strip-line kickers can make only1.3mrad kick angle. It is not enough for the kick angle to extract the beam. Replacement plan from kicker magnet to strip-line kicker

12. Beam extraction design with two strip-line kicker The kick angle of the strip-line kicker is not enough to make the beam extraction orbit. A design uses pulse bump magnets and an auxiliary septum magnet, which has thin separator, to help in making the extraction orbit. This design makes a bump orbit after the beam damping, then the selected beam is extracted bunch-by-bunch by the strip-line kicker.

13. Timing chart of 60(30) bunches beam extraction The bump orbit is gradually increased after all of the bunches have been damped. The strip- line kicker kicks out the beams at the timing of the flat-top of the bump orbit. The beams are extracted as one long bunch train, which is a 10micro-sec long with 154ns (or 308 ns) spacing.

14. Local bump test by using present magnets and DC power supplies(1) The aperture survey was carried out by using present magnets and DC power supplies. The required bump height is 5mm to separate the extraction beam and the circular beam. However, the local bump could make only +4mm and -2mm height.

15. Local bump test by using present magnets and DC power supplies(2) Bump height The measurement has agreed with the optics settings. The aperture limit at +4mm and -2mm are assumed that the limits show the miss-alignment of the septum or a large orbit distortion at the location.

16. Beam extraction design with two strip-line The bump orbit is optimized to eliminate the aperture limit at the septum area. This design has no orbit change at the septum area, however the bending angle of the bump magnets is increased. Bump orbit

17. Required magnet parameters 1.Magnets(not yet designed) Steering magnets Bending angle: 9mrad(max) Effective length 100mm 0.4T(max) Septum magnet Bending angle: 14mrad 1000AT, 0.6m, 1 turn coil 2.Power supplies Steering magnets - 50A(MAX), 10V(pulse) Septum magnet - 1000A, 1V(DC)

18. Proposed Schedule 10kV fast pulser order and test Summer 2007 Fabrication strip-line electrodes Fall 2007 Fabrication bump magnets and pulse PS Summer 2007 Pulse bump magnet test Fall 2007 Fabrication Septum magnet Fall 2007 - Installation strip-line electrodes and septum Spring 2008 Beam test Spring 2008