The CLIC Beam Delivery System R. Tom as Thanks to the input of - - PowerPoint PPT Presentation

The CLIC Beam Delivery System

• R. Tom´

as Thanks to the input of many: D. Angal-Kalinin,

• G. Burt, B. Dalena, J.L. Fernandez, L. Gatignon,
• E. Mar´

ın, M. Modena, J. Osborne, J. Resta,

• G. Rumolo, H. Schmickler, D. Schulte, A. Seryi,
• J. Snuverink, G. Zamudio

IWLC 2010, October 2010

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.1/14

Contents

• The BDS CDR chapter
• CLIC BDS layouts
• Subsystems
• Issues & challenges
• Summary & outlook

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.2/14

The BDS CDR chapter

“Live” Draft at: clicr.web.cern.ch/CLICr/MainBeam/BDS/CDR/TEX Everybody is welcome to take a look and send criticism to: D. Angal-Kalinin (CI), A. Seryi (JAI) and R. Tom´ as (CERN)

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.3/14

The BDS layouts at 3 TeV and 500 GeV

• 1
• 0.8
• 0.6
• 0.4
• 0.2

0.2

• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 500 GeV 3 TeV

Guillermo Zamudio

3 TeV needs weak dipoles (20-120 G) due to SR. To keep the linac unchanged the IP crossing angle at 500 GeV is reduced to 18.6 mrad. Both BDS easily fit in same tunnel.

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.4/14

Diagnostics and Energy collimation

• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2

• 2800
• 2600
• 2400
• 2200
• 2000
• 1800

x[m] s[m] Coupling correction laser wires Polarization IP laser energy spoiler absorver 20 40 60 80 100 120 140 160 180 200

• 2800
• 2600
• 2400

βx,y [m] βx βy 20 40 60 80 100 120

• 2200
• 2000
• 1800

βx,y[km], Dx[cm] βx βy Dx

σy = 1µm at laser wires. Energy spoiler must survive a full train impact.

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.5/14

Transverse collimation and FFS

• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2

• 1000
• 800
• 600
• 400
• 200

x[m] s[m] FD betatron collimators muon spoilers crab cavity 100 200 300 400 500 600

• 1000
• 800
• 600

βx,y [m]

• 50

50 100 150 200 250 300

• 200

βx,y[km], Dx[mm] βx βy Dx

Betatron collimators are consumable. Muon spoilers reduce the muon flux in the detector. Crab cavity restores the luminosity loss from a 20 mrad crossing.

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.6/14

Low field dipoles

Cherril Spencer (SLAC)

Measurements show no enhancements of multi- poles at 1/140 of the design current. Insulation from stray fields?

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.7/14

Collimation

• a

φ z

T

L L L d b

F T T

θ

Javier Resta (Oxford) Luis Fernandez (CI)

Simulation galore confirming: collimation effi- ciency, moderate wakefileds effects, survivability

• f 1st spoiler (temperature & stress), etc.

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.8/14

Muons

Lawrence Deacon (RHUL)

A factor 10 reduction in muon flux with 83 m of magnetized iron (outer radius 55 cm).

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.9/14

Crab Cavities

Graeme Burt, Amos Dexter et al

Tight phase stability specs and high order mode damping. Recently found that by design (optics) there is ≈5% lumi loss!

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.10/14

The FFS: CLIC Vs ILC

CLIC 20% lumi loss from SR σy ≈ 1 nm βy = 70 µm

• Chroma. ≈ 6.3 × 104

IP D′

x= 1.4 mrad

Energy spread ≈ 0.3% ILC Negligible SR σy ≈ 6 nm βy = 400 µm

• Chroma. ≈ 1.5 × 104

IP D′

x= 9 mrad

Energy spread ≈ 0.1% CLIC FFS is considerably more challenging in every aspect. ATF2 is the common playground but CLIC requires Ultra-low IP β (see E. Mar´ ın’s talk).

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.11/14

L* alternatives and performance

L* total lumi peak lumi m 1034cm−2s−1 1034cm−2s−1 3.5 6.9 2.5 4.3 6.4 2.4 6 5.0 2.1 8 4.0 1.7

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.12/14

Tuning performance for different L*

• B. Dalena & G. Zamudio

relative absolute L* prealignment success success [m] [µm] [%] [%] 3.5 10 65 87∗ 4.3 10 80 100 6 8 80 90 8 2 80 46

∗ Recently improved by a better design and the

use of knobs

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.13/14

Summary & outlook

• CLIC BDS CDR chapter well advanced

(waiting for your feedback!)

• No major problem...
• Thanks to excellent international

collaborations!

• Alignment and tuning remains as the biggest

challenge → lots to learn in ATF2!

• For the TDR phase:
• New designs that consider tuning and

CCs from the start?

• wakefields in FACET

Rogelio Tom´ as Garc´ ıa The CLIC Beam Delivery System – p.14/14