Alignment system and impact on CLIC two-beam module design

1. CTC meeting – 2009.06.16 Alignment system and impact on CLIC two-beam module design H. Mainaud-Durand, G. Riddone

2. Content • Baseline for alignment/supporting system • Impact on module design • Future actions

3. Module alignment/supporting systems • Main beam accelerating structures • Drive beam PETS and Q • Main beam Q (link to stabilisation system) Connected via the inter-beam waveguides Connected via the beam pipe

4. Module types and numbers Type 0 Total per module 8 accelerating structures 8 wakefield monitors 4 PETS 2 DB quadrupoles 2 DB BPM Total per linac 8374 standard modules DB MB

5. Module types and numbers • Total per linac • Quadrupole type 1: 154 • Quadrupole type 2: 634 • Quadrupole type 3: 477 • Quadrupole type 4: 731 • Other modules • modules in the damping region (no structures) • modules with dedicated instrumentation • modules with dedicated vacuum equipment • … Type 1 Type 3 Type 2 Type 4

6. Module type 1

7. Module type 1 views

8. Main requirements • 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 errorat 1 sigma: 17 um • Stabilization (rms position errors at 1sigma): • 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

9. Pre-alignmentstrategy • Overlapping straight references • Propagation network  a few microns over more than 200 m • Proximity network  a few microns over 10-15 m.

10. Pre-alignmentstrategy • Baseline: straight reference = stretched wire. • propagation network : WPS sensors • proximity network: WPS sensors

11. Pre-alignmentstrategy • Alternative: • propagation network = wire, • proximity network = RASNIK

12. Pre-alignmentstrategy WPS system (follows the slope) HLS system (horizontal) Proximity sensors (RASNIK), mechanically linked to each cradle

13. Impact on module design and baseline • 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

14. 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)

15. CTF2-based snake system CTF2 Continuity between girders All MB girders have the same length MB Q support passes over the MB girder MB Q beam pipe and AS beam pipe are coupled via bellows

16. Module snake system 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 lowered MBQ support simplified MB Q beam pipe and AS beam pipe are coupled via bellows

17. Module sections IP Close to IP  better alignment

18. Typical module sequences

19. Impact on transport/installation  tunnel integration Strategy: installation of WPS before the module

20. Future actions • 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)

21. 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) 21 CTC, HMD and GR, 6/16/2009