Technical systems in the BDS R. Tom as Thanks to the input of - - PowerPoint PPT Presentation

Technical systems in the BDS

• R. Tom´

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

• G. Burt, B. Dalena, J.L. Fernandez, L. Gatignon,
• M. Modena, J. Osborne, J. Resta, H. Schmickler,
• D. Schulte, A. Seryi, J. Snuverink, G. Zamudio

IWLC 2010, October 2010

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.1/33

Contents

• 500 GeV and 3 TeV BDS optics, beam pipe

aperture and layouts

• instrumentation: emittance, energy

measurements

• tune-up dump
• Polarization measurement
• Collimation
• FFS, different L* and tuning
• QD0 specifications
• Crab cavity specifications
• magnets, quads, dipoles, specs

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.2/33

The 500 GeV BDS

50 100 150 200 250 300 350 400 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

• 0.3
• 0.2
• 0.1

0.1 0.2 0.3 0.4 β1/2 [m1/2] D [m] Longitudinal location [km] Diagnostics Collimation Final Focus system βx

1/2

βy

1/2

Dx

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.3/33

The 3 TeV BDS

100 200 300 400 500 600 0.5 1 1.5 2 2.5 3

• 0.05

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 β1/2 [m1/2] D [m] Longitudinal location [km] Diagnostics Energy collimation Transverse collimation Final Focus system βx

1/2

βy

1/2

Dx

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.4/33

Beam pipe apertures

5 10 15 20 25

• 3
• 2.5
• 2
• 1.5
• 1
• 0.5

Radius [mm] Longitudinal location [km] 3Tev 500Gev

Reference beam pipe radius 8 mm at 3 TeV and 12 at 500 GeV. Tight apertures (3-5mm) at 3.5 TeV (FFS).

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.5/33

The tunnel

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.6/33

The layouts and the tunnel in 2009

• 2
• 1

1 2 3 4

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 3Tev e- BDS 500Gev e- BDS (previous) Tunnel

Not enough space for both beam lines!

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.7/33

The layouts and the tunnel fixed

• 2
• 1

1 2 3 4

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 3TeV 20mrad 500GeV 18.6mrad linac (0.6mrad) 3Tev e- BDS tune-up dump(?) 500Gev e- BDS Tunnel?

Enough space and both beam lines aligned to the linac

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.8/33

Diagnostics: emittance measurement

0.0 50. 100. 150. 200. 250. 300. 350. 400.

s (m) End of Linac - Diagnostics section

0.0 50. 100. 150. 200. 250. 300. 350. 400.

βx (m), βy (m)

β x β y

SQ1 SQ2 SQ3 SQ4 LW1 LW2LW3 LW4

σy=1µm @ Laser wires (for ǫy=20nm)

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.9/33

Diagnostics inside collimation

0.0 200. 400. 600. 800. 1000.

s (m) Diagnostics-Collimation

0.0 20. 40. 60. 80. 100. 120.

β

x (m), β y (m)

[*10**( 3)]

0.0 0.025 0.050 0.075 0.100 0.125 0.150 0.175 0.200 0.225 0.250 0.275 0.300

D

x (m)

β x β y Dx

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.10/33

Layout & photon collection

• 0.1
• 0.05

0.05 0.1 400 500 600 700 800 900 1000 1100 1200 Horizontal displacement [m] Longitudinal location [m] Beam diagnostics beam line Laser wire photons Dipoles for energy col. photon detector

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.11/33

CLIC compact energy measurement

First Collimation Dipole as Spectrometer BPM BPM BPM (σ=0.1µm) 5×10-4m 20m α=2.5×10-5rad BL=0.125 Tm ∆(BL)/BL≈10-4 Bρ=5000 Tm ∆E/E=∆α/α ⊕ ∆(BL)/BL≈3.6×10-4 First Collimation Dipole as Spectrometer BPM BPM BPM (σ=0.1µm) 5×10-4m 20m α=2.5×10-5rad BL=0.125 Tm ∆(BL)/BL≈10-4 Bρ=5000 Tm ∆E/E=∆α/α ⊕ ∆(BL)/BL≈3.6×10-4

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.12/33

BDS dumps: tune-up and main dump

Tunnel widens up to 10m in the extraction region

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.13/33

1st option: 2 extraction points

• 1
• 0.8
• 0.6
• 0.4
• 0.2

0.2

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 3TeV 20mrad 500GeV 18.6mrad linac (0.6mrad) Tune-up dump extraction & transfer lines 3Tev e- BDS tune-up dump(?) 500Gev e- BDS

Total of 4 dumps

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.14/33

2nd option: 1 extraction point

• 0.7
• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 3TeV 20mrad 500GeV 18.6mrad linac (0.6mrad) Tune-up dump extraction line

Total of 4 dumps

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.15/33

3rd option: use main dump

• 0.8
• 0.7
• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] 3TeV 20mrad 500GeV 18.6mrad linac (0.6mrad) main dump extraction line 3Tev e- BDS tune-up dump(?)

Total of 2 dumps

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.16/33

Polarization measurement

• 2
• 1.5
• 1
• 0.5

0.5 500 1000 1500 2000 2500 3000 x[m] Longitudinal location [m] BDS layout IP directions (0.6mrad)

Best location parallel to IP at about 700m.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.17/33

Polarization measurement (P . Schuler)

• IP laser at 742 m
• Standard Q-switched YAG laser (100mJ at

532nm wavelength)

• 10mrad and a laser spot size of 50 mm
• Compton electron detector at s=907 m
• 12 larger aperture dipoles (up to 300mm) are

required from IP laser to the Compton electrons detector

• Resolution: 0.61% and 0.08% for

measurement times of 1 s and 60 s, respectively

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.18/33

The collimators I

• 0.7
• 0.6
• 0.5
• 0.4
• 0.3
• 0.2
• 0.1

0.1 0.2

• 3000
• 2500
• 2000
• 1500
• 1000
• 500

x[m] s[m] IP 3TeV 20mrad 500GeV 18.6mrad linac (0.6mrad) 3Tev e- BDS 500Gev e- BDS collimators

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.19/33

The collimators II

Name βx βy Dx ax ay Geom. Mat. [m] [m] [m] [mm] [mm] EYSP 1406 70681 0.27 3.51 25.4 rect Be EYAB 3213 39271 0.42 5.41 25.4 rect Ti the following ×4 YSP1 114 483.2 0. 8. 0.1 rect Ti? XSP1 270 101.3 0. 0.12 8. rect Ti? XAB1 270 80.90 0. 1. 1. ellip Ti YAB1 114 483.1 0. 1. 1. ellip Ti

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.20/33

The Be spoiler

• rad

θ =0.03

T

0.5 X = 17.65 cm Be

a=3.51 mm b=6.21 mm 2 mm

z

1.5 TeV e beam

−

First design. Presently under optimization.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.21/33

Spoiler angle optimization (J. Resta)

8 mrad tapering angle gives better performance than 30 mrad.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.22/33

Temperature after beam impact

20 40 60 80 100 120 140 140 160 180 200 220 240 260 280 Distance [mm] Temperature increment [K] Increment of temperature in a Be spoiler with shallow tapers (no body) hit by a CLIC train

No risk of melting.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.23/33

Stress from beam impact (J.L. Fernandez)

No risk of fracture, but collimators should be tested for compressive stresses up to 200 MPa.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.24/33

Total and peak luminosities Vs L*

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 Technical systems in the BDS – p.25/33

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

∗ very recent improvement with new design and

tuning knobs

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.26/33

Some QD0 specifications

L* m 3.5 4.3 6.0 8.0 Gradient T/m 575 382 200 211 Length m 2.7 3.3 4.7 4.2 Beam aperture mm 3.5 6.7 8 8.5 Jitter tolerance nm 0.15 0.15 0.2 0.18 Gradient tol 10−6 5 5

• 3

Prealign. µm 10 10 8 2

• Long. prealign.

µm 25

• 40
• Rogelio

Tom´ as Garc´ ıa Technical systems in the BDS – p.27/33

2% luminosity sensitivity to quad offset

s (m) 1000 2000 3000 quad offset (um)

• 3

10

• 2

10

• 1

10 1 10

With corrected IP offset (J. Snuverink) 3 nm for QD0, 10-50 nm for a few quads and >50 nm for most. This gives and indication on the required BPM resolution.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.28/33

BDS dipoles specifications

• BDS dipoles range between 20 and

120 Gauss

• Most need 24mm aperture (radius), few need

150mm.

• Field relative precission and jitter must be

≤ 10−4 (first promissing measurements from

• C. Spencer (SLAC))
• Sextupolar error at 10mm must be ≤ 6 × 10−4
• Daniel suggested to use SC dipoles to shield

stray fields

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.29/33

Crab Cavity (A. Dexter & G. Burt)

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.30/33

Crab Cavity specifications

• 12 GHz
• phase stability 0.02◦
• amplitude stability 2%
• strong HOM damping
• New simulations from G. Burt show some

perfomance reduction from ideal. To be followed up. Adequate design and parameter choice needed to meet specifications.

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.31/33

BDS Numbers

type quantity total length Dipoles 206 1.3 km Quadrupoles 70 0.19 km Sextupoles 18 34 m BPMs ≈100

• Collimators

18

• Rogelio

Tom´ as Garc´ ıa Technical systems in the BDS – p.32/33

Summary - The challenges

• Jitter tolerances
• Pre-alignment tolerances
• Field jitter and accuracy
• Robust tuning

Rogelio Tom´ as Garc´ ıa Technical systems in the BDS – p.33/33