1. REQUIREMENTS FOR FCC DILUTION KICKERS AND BEAM DUMP LINE GEOMETRY F. Burkart, W. Bartmann, M. Fraser, B. Goddard, T. Kramer FCC dump meeting 18 th June 2015

2. Outline Current status @ LHC Dilution kicker requirements Beam dump line geometry Conclusion 18/06/2015FCC dump meeting 2

3. Reminder – LHC system 18/06/2015FCC dump meeting 3 MKBH Magnets per system4 Max. system defl. angle0.278 mrad Kick strength per magnet1.624 Tm Hor. aperture58 mm Ver. aperture32 mm Frequency14.2 kHz MKBV Magnets per system6 Max. system defl. angle0.277 mrad Kick strength per magnet1.077 Tm Hor. aperture66 mm Ver. aperture36 mm Frequency12.7 kHz Dilution kickers MKB Dump block TDE ~ 600 m

4. Installation in the tunnel 18/06/2015FCC dump meeting 4 Courtesy: L. Ducimetiere

5. BTVDD screenshot 18/06/2015FCC dump meeting 5

6. FCC beam dumps ~ 10600 bunches with a bunch spacing of 25 ns. Bunches separated by 1.8 mm on the TDE (Given by max. Temperature in Carbon (1500 Celsius) - A. Lechner). Bunch equally spaced dumped on the beam dump block.  Requires frequency modulation of the dilution kicker. 18/06/2015FCC dump meeting 6

7. How it should look like: 18/06/2015FCC dump meeting 7 R=20 cm

8. Zoom into the first bunches 18/06/2015FCC dump meeting 8 1.95 mm 6 mm

9. Frequency and amplitude of the dilution kickers 18/06/2015FCC dump meeting 9

10. Frequency modulation 18/06/2015FCC dump meeting 10

11. Requirements for FCC dilution kickers B rho @ 50 TeV: 166.666 Tm Max deflection angle with the current design @ 50 TeV: 0.044 mrad  Drift space between MKB and TDE: 4.6 km Possible Mitigations: Increase number of elements. Increase of current. Tilted MKB to gain in both planes.?? Install Quadrupole to get more kick: Variation of the drift length  beam dump line geometry. 18/06/2015FCC dump meeting 11 MKBH MKBV Quad

12. FCC layout 18/06/2015FCC dump meeting 12 2 dump insertions (length: 4.2 km ). Extraction and betatron collimation.

13. Beam dump line geometry (1/3) 18/06/2015FCC dump meeting 13 1.4 km dump insertion2.8 km collimation insertion 2 km dump line 2 km dump line (for dilution system / drift) Dump cavern should be separated from circulating beam. Dumped beam is only about 0.7 m separated in hor. plane from FCC circulating beam, after 2 km. Needs ~100 m of 16 T dipole at 167’000 Tm. Courtesy: W. Bartmann

14. Dump line elements 1.4 km dump insertion 2.0 km dump line Kicker Septum 10 mrad bend MKB Absorber 18/06/2015FCC dump meeting 14  Would require: 0.12 mrad total deflection in the MKB,  Keep aperture from LHC MKB= 11 magnets (hor).  Min. extraction energy: 3.3 TeV – gain factor 7 (energy-scaling) in aperture? Will be reduced by higher  2.8 km collimation

15. Beam dump line geometry (2/3) 1.4 km dump insertion2.8 km collimation insertion 2 km dump line 2 km arc bend gives 150 mrad angle 150 m separation between dump cavern and ring. No additional dipoles needed. Collimation in the downstream arc needed. 18/06/2015FCC dump meeting 15 Courtesy: W. Bartmann

16. Dump line elements 1.4 km dump insertion 2 km dump line Kicker Septum MKB Absorber 18/06/2015FCC dump meeting 16 arc  Would require: 0.099 mrad total deflection in the MKB.  Keep aperture constant = 9 magnets (hor).

17. Beam dump line geometry (3/3) 18/06/2015FCC dump meeting 17 1.4 km dump insertion2.8 km collimation insertion 2 km dump line ~ 1 km dump line Feed dump line through collimation insertion. Reduces complexity of the system – less kick strength needed in kicker and septum, no additional dipoles, no additional collimation in the arc. Radiation limitations? Hot area – access limitations? Bigger tunnel diameter? Distance between collimator and dump line?

18. Dump line elements 18/06/2015FCC dump meeting 18 1.4 km dump insertion 2 km dump and collimation line Kicker Septum Absorber Collimation MKB arc  Would require: 0.055 mrad total deflection in the MKB.  Keep aperture constant = 6 magnets (hor).

19. Conclusions MKB requirements: max. deflection between 0.1 mrad and 0.055 mrad depending on dump insertion geometry. Frequency up to 10 MHz. First assumption: keep apertures as in LHC. How much redundancy needed? 3 options for beam dump insertion design. With 100m dipoles and collimation downstream. Without dipoles and with dedicated collimation. Going straight through collimation insertion into beam dump line using arc separation 18/06/2015FCC dump meeting 19 Feasible?

20. 18/06/2015FCC dump meeting 20 Thank you for your attention!

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