1. Some ideas to optimise PSB injection chicane Wim, Brennan, Jan, Masamitsu

2. ‘LINAC4 Design Report’ 66 mrad, -0 mm, 250 mm magnetic length, 27mm KSW, 24.1 FOM.

3. Baseline Design 66 mrad, -0 mm, 250 mm magnetic length, 27 mm KSW, 18.3 FOM.

5. 50% BS field

7. Figure of merit is taken as (kick angle * magnetic field) -1 Beta-beat ~66 / FOM Parameters to reduce beta-beating –Offset of Injected beam (~10mm) –Increased Injected Beam Angle (max 80mrad) –Reduced BS angles –Increase Magnet Length (250 – 400mm) –Increased Painting Bump

8. 1. Vary injected beam position (steering magnets in BI line)

9. Magnet Length versus Injected beam offset for 27 mm painting bump and 66 mrad BS1 angle ~287

10. 2. Vary injected beam angle (double-field septum BS1)

11. Injected beam angle versus Magnet length for 27 mm painting bump and 0 mm injected beam offset ~287

12. 3. Increase KSW bump

13. Increasing KSW – aperture? Initial assumptions for plotting aperture and envelopes –Booster dipole H apertures are ±50 mm –align = 0.001; % [m] alignment precision –mech = 0.001; % [m] mechanical precision –sagitta = 0.0000; % [m] vertical sagita of chambers –traj_max = 0.004; % [m] max trajectory excursion –dp_p = 0.00658; % max p error (0.438% painting plus 0.2% spread) –K_beta = 1.1; % optical mismatch factor in beta –K_inj = 2.4; % injection mismatch factor –e_n_x = K_inj * 0.439e-6; % [m.rad] H normalised emittance –e_n_y = K_inj * 0.439e-6; % [m.rad] V normalised emittance –betagamma = 0.608; % relativistic beta * gamma at 4 GeV kinetic –n_sig = 3;

14. 27mm KSW

15. 37 mm KSW

16. Maximum KSW bump? Could accept 35 mm KSW bump IF main dipole aperture can be ±60 mm –To confirm

17. 35 mm KSW bump

18. 35 mm KSW

19. 4. Combining KSW and injected beam position/angle

20. 35 mm KSW, -6mrad inj

21. 35 mm KSW, -10mm inj Looks most promising….

25. Possible options 35 mm KSW plus -10 mm steering of BI beam –Needs possibility of steering in BI line – check strengths and apertures. –Needs +/-60 mm aperture in adjacent dipoles – check drawings –Helps with moving beam away from foil at end of painting process –Gives ~15% beta beating in H-plane for full BS strength – and ~7% in both planes at 50% strength (using SBENDS) – check effects on dynamics