REQUIREMENTS FOR FCC DILUTION KICKERS AND BEAM DUMP LINE GEOMETRYF. Burkart, W. Bartmann, M. Fraser, B. Goddard, T. Kramer

FCC dump meeting18th June 2015

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Outline

• Current status @ LHC• Dilution kicker requirements• Beam dump line geometry• Conclusion

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Reminder – LHC system

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MKBH

Magnets per system 4

Max. system defl. angle 0.278 mrad

Kick strength per magnet 1.624 Tm

Hor. aperture 58 mm

Ver. aperture 32 mm

Frequency 14.2 kHz

MKBV

Magnets per system 6

Max. system defl. angle 0.277 mrad

Kick strength per magnet 1.077 Tm

Hor. aperture 66 mm

Ver. aperture 36 mm

Frequency 12.7 kHz

Dilution kickersMKB

Dump blockTDE

~ 600 m

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Installation in the tunnel

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Courtesy: L. Ducimetiere

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BTVDD screenshot

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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.

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How it should look like:

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R=20 cm

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Zoom into the first bunches

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1.95 mm 6 mm

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Frequency and amplitude of the dilution kickers

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Frequency modulation

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Requirements for FCC dilution kickers

• B rho @ 50 TeV: 166.666 Tm• Max deflection angle with the current design @ 50 TeV: 0.044 mradDrift 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.

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MKBH MKBVQuad Quad

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FCC layout

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• 2 dump insertions (length: 4.2 km ).• Extraction and betatron collimation.

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Beam dump line geometry (1/3)

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1.4 km dump insertion 2.8 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

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Dump line elements

1.4 km dump insertion

2.0 km dump line

Kicker Septum 10 mrad bendMKB

Absorber

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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 .b

2.8 km collimation

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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.

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Courtesy: W. Bartmann

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Dump line elements

1.4 km dump insertion 2 km dump line

Kicker Septum MKBAbsorber

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arc

Would require: 0.099 mrad total deflection in the MKB. Keep aperture constant = 9 magnets (hor).

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Beam dump line geometry (3/3)

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1.4 km dump insertion 2.8 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?

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Dump line elements

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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).

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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

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Feasible?

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Thank you for your attention!

FCC dump meeting 2118/06/2015