April 10, 2007 LHCCWG - Frank Schmidt, ABP 1

Do we have an Aperture Kicker for Do we have an Aperture Kicker for the LHC?the LHC?

- Kicker Hardware

- Kick Classification

- Examples

- DA at Injection and Collision

- Conclusion

April 10, 2007 LHCCWG - Frank Schmidt, ABP 2

KickerKicker

April 10, 2007 LHCCWG - Frank Schmidt, ABP 3

Puls GeneratorPuls Generator

MKQMKQ MKAMKA

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3300V

800V

900V

Circuit DiagramCircuit Diagram

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The “Keys” in CCRThe “Keys” in CCR

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Kick Classification Kick Classification

Basic Optics

MKQ

≤ 2 Tune, Phase Advance, Linear Coupling, Beta-beat…

Detailed Optics

AC-Dipole, MKA

2 – 6 Beta-beat, Non-Linear Optics, Corrections

Dynamic Aperture

MKA, AC-Dipole

≥ 6 Stable & Chaotic Motion, Particle Loss, Lifetime

April 10, 2007 LHCCWG - Frank Schmidt, ABP 7

Linear Coupling (SPS)Linear Coupling (SPS)

R. TomR. Tomás et al.ás et al.

Linear coupling compensation and tracking data at all BPMs to compare the machine model to the data

Linear coupling can be treated as any other resonance

April 10, 2007 LHCCWG - Frank Schmidt, ABP 8

Missing Sextupoles (SPS)Missing Sextupoles (SPS)

(F. Schmidt, R. Tomas et al.)(F. Schmidt, R. Tomas et al.)

Specially arranged SPS configuration for extraction sextupoles

+ + + + - - - -

(3,0) resonance driving terms

Data fully decohered (factor 2 correction applied)

Comparison with nominal model

One extraction sextupole accidentally disconnect

Before

After

April 10, 2007 LHCCWG - Frank Schmidt, ABP 9

Uncompensated Skew Sextupole Resonance Uncompensated Skew Sextupole Resonance (PSBooster) (PSBooster) (P. Ursch(P. Urschüütz, M. Benedikt)tz, M. Benedikt)

CERN PS data

vertical plane

3Qy = 16

and

(0, -2) spectral line

Uncorrected machine

vertical motion

beam losses

phase space

FFT

April 10, 2007 LHCCWG - Frank Schmidt, ABP 10

Corrected Skew Sextupole Resonance Corrected Skew Sextupole Resonance (PSBooster) (PSBooster) (P. Ursch(P. Urschüütz, M. Benedikt)tz, M. Benedikt)

CERN PS data

vertical plane

3Qy = 16

and

(0, -2) spectral line

Resonance compensated with skew sextupoles

Setting based on the reduction of the (0, -2)

line amplitude

vertical motion

beam losses

phase space

FFT

April 10, 2007 LHCCWG - Frank Schmidt, ABP 11

Dynamic Aperture SPS 1988/89Dynamic Aperture SPS 1988/89 Gareyte, Hilaire, Schmidt et al.Gareyte, Hilaire, Schmidt et al.

April 10, 2007 LHCCWG - Frank Schmidt, ABP 12

DA at Injection and CollisionDA at Injection and Collision

MKQ MKA

AC-

Dipole

DA DA-BB

Injection 1.62 5 16 11 7

Collision 0.41 1.4 4 9-15 5.5

April 10, 2007 LHCCWG - Frank Schmidt, ABP 13

ConclusionConclusion

• Except for may be the AC-dipole at Injection the answer to the original question is:

NO, we do not have an Aperture Kicker!!

• BUT: If we are really courageous we can upgrade the MKA from 890V to 4kV

Injection: 22.5 Collision: 6.3 • No hardware upgrade except:

April 10, 2007 LHCCWG - Frank Schmidt, ABP 14

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