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
5
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
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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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