Alignment system and impact on CLIC two-beam module design

H. Mainaud-Durand, G. Riddone

CTC meeting – 2009.06.16

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Content

Baseline for alignment/supporting system

Impact on module design

Future actions

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Module alignment/supporting systems

Main beam accelerating structures

Drive beam PETS and Q

Main beam Q (link to stabilisation system)

Connect

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Module types and numbers

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Type 0

Total per module8 accelerating structures8 wakefield monitors

4 PETS2 DB quadrupoles2 DB BPM

Total per linac8374 standard modules

DB

MB

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Module types and numbers

CTC, HMD and GR, 6/16/2009

Total per linacQuadrupole type 1: 154Quadrupole type 2: 634Quadrupole type 3: 477Quadrupole type 4: 731

Other modules- modules in the

damping region (no structures)

- modules with dedicated instrumentation

- modules with dedicated vacuum equipment

- …

Type 3Type 1

Type 2 Type 4

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Module type 1

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Module type 1 views

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Main requirements

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accelerating structure pre-alignment transverse rms position error at 1 sigma : 14 um (shape accuracy for acc. structures: 5 um)

PETS pre-alignment transverse rms position error at 1 sigma: 30 um (shape accuracy for PETS: 15 um)

Main beam quadrupole: Pre-alignment transverse rms position error

at 1 sigma: 17 um Stabilization (rms position errors at 1 sigma):

1 nm > 1 Hz in vertical direction 5 nm > 1 Hz in horizontal direction

Module power dissipation : 7.7 kW (average) (~ 600 W per ac. structure)

Vacuum requirement: few nTorr

Temperature

stabilization for any operation

mode is an important

issue

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Pre-alignment strategy

Overlapping straight references

Propagation network a few microns over more than 200 m

Proximity network a few microns over 10-15 m.

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Baseline: straight reference = stretched wire.

propagation network : WPS sensors

proximity network: WPS sensors

Pre-alignment strategy

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Alternative:

propagation network = wire,

proximity network = RASNIK

Pre-alignment strategy

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Pre-alignment strategy

HLS system (horizontal)

Proximity sensors (RASNIK), mechanically linked to each cradle

WPS system (follows the

slope)

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Impact on module design and baseline

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Accelerating structures and PETS + DB Q on girders (same beam height)

Girder end supports cradles mechanically attached to a girder and linked by rods to the adjacent one: snake-system adopted(DB: 100 A, MB: minimization of wake-fields, validation at 30 GHz in CTF2)

Separate girders for main and drive beam possibility to align DB quadrupole separate from accelerating structures

Separate support for MB Q and its BPM MB Q and BPM rigidly mechanically connected Common actuators/devices for stabilization and beam-

based feedback systems 13

Main components for alignment/supporting system Movers

Linear (girders) (under design, HMD team) Cam system (MB Q to be confirmed )

Girder MB: first design iteration done (NG) DB: launched simulation (NG)

Girder Supports End supports snake system (collaboration module-alignment activities)

MBQ support MB Q pre-alignment system (under design, FL) MB Q support (to be start LAPP) Stabilization (several people)

Sensors for pre-alignment (under design, HMD team) Sensors for stabilization (under design, K. Artoos and colleagues)

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CTF2-based snake system

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Continuity between girdersAll MB girders have the same lengthMB Q support passes over the MB girderMB Q beam pipe and AS beam pipe are coupled via bellows

CTF2

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Module snake system

CTC, HMD and GR, 6/16/2009

No full continuity between MB girders (increasing of align. cost)MB girder length changes as function of module type No girder underneath MB Q Beam height loweredMBQ support simplified MB Q beam pipe and AS beam pipe are coupled via bellows

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Module sections

0

1

2

3

4

840 845 850 855 860 865 870

0

1

2

3

4

5010 5020 5030 5040 5050 5060 5070 5080

0

1

2

3

4

20090 20100 20110 20120 20130 20140 20150

Close to IP better alignment

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IP

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Typical module sequences

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Impact on transport/installation tunnel integration

Strategy: installation of WPS before the module

Future actions

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• By Sept 2009 (for module review scheduled on 15-16/09) Movers: concept existing, check compatibility with

requirements (weight, resolution,..) pre-alignment WG Girder: size DB girder Module WG (NG) Articulation point: concept existing, check requirement

fulfillment pre-alignment WG Stabilization system: define concept (stab WG) and then

module integration MB Q support: define concept and then module integration

(LAPP) Define and justify height requirements for the MB Q (stab WG) BPM-Q connection: implication on beam instrumentation

(instrumentation WG, stab WG, module WG)

Future actions

Before CDR Girder mock-up to test alignment system and compatibility with

interconnection design (inter-beam and inter-girder), as well as stability during transport and heat cycles ==> ready by Q1 2010 also collaboration with PSI

Module demonstrator type x (it will integrate the Q mock-up, ready by Q2 2010 qualification for particle beam)

After CDR Test module type 0 (2011) Test module type 1 (2012)

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