AWAKE Experiment

1. Laser Beam Transport and Integration.AWAKE Collaboration meeting.Mikhail Martyanov ChristophHessler CERN, EN-STI-LPValentin FedosseevCERN 09-11.04.2014

2. AWAKE Experiment Control room 1km AWAKE gallery e-gun room Laser room SAS CV e- beam p+ / e- diagnostics Laser safety shutters Fast valves Laser dump plasma laser beam p+ beam Laser / p+ merging point e- spectrometer Laser shutters M.Martyanov, CERN

3. Overview • Short intense laser pulse is needed for: • to create a 100% ionized plasma • moving ionization front is a source of perturbation for proton-laser instability (micro-bunching and wake-field with a stable phase) • Plan for the Laser system: • First it is delivered to MPP Munich for plasma experiments - mid 2014 • Then it goes to CERN - Autumn 2015 M.Martyanov, CERN

4. Overview • Laser system comprises: - laser with 2 beams (for plasma and for the e-gun) - delay line is possible in either one of these beams - focusing telescope (lenses, in air), long 40m focusing - optical compressor (in vacuum) - small optical in-air compressor and 3rd harmonics generator for e-gun • Laser parameters for plasma: - max energy 450 mJ - pulse duration 120 fs after compression - max beam diameter 40 mm Only reflective optics on the way Rule of thumb (B<1): I[GW/cm2]L[cm]<36 M.Martyanov, CERN

5. Laser System Base-line • Laser, Telescope and Compressor are in the laser room • Focusing down to 40 meters to the center of the plasma • Back solution: Compressor and Telescope are next tomerging point in the proton tunnel • Focusing down to 25 meters to the center of the plasma • Question is if this possible? Crucial points are: • Focusability of the laser beam down to 40 meters, ionization dynamics, diffraction? • No detailed information on the laser system yet (beam quality) • The placement of the optical compressor and the focusing telescope has an impact on the position of the anew drilled connection tunnel • Availability of vacuum components for the compressor and telescope is under study. • 10-6Torr “easily” achievable. Pellicle or differential pumping as an option to go better M.Martyanov, CERN

6. Scope of Laser Line WP • Laser room preparation • Clean room, cooling and ventilation, facilities • Access control • Laser transfer line to the plasma cell • HV vacuum line • Remote control of the mirrors • Laser beam position monitoring • Laser transfer line to the photo-gun • Fore-vacuum line • Remote control of the mirrors • Laser beam position monitoring • In-air compressor and 3rd harmonic generation <- Electron source WP • Laser installation • Laser arrangement on the tables • Integration to the AWAKE environment M.Martyanov, CERN

7. Arrangement in the Laser Room Fore-vacuum laser transfer line for e-gun (on the ceiling) 0.9m 2 x 1 m optical table 2.5 x 1 m optical table 2 x 1 m optical table 2.5 x 1 m optical table ~1m CV units 1m compressor SAS PP+ power supply 600x600x(H)850 CCM rack 700x800x(H)1400 3m 4m M.Martyanov, CERN

8. Laser Arrangement on the Tables Three optical tables: 2x1, 2.5x1, 2.5x1 m 1 – MENLO oscillator, 500x500 2 – Stretcher, 1000x500 3 – Regen / preamp, 1000x800 4 – Green pump for (3) 5 – 600mJ amplifier, 1500x800 6 – Green pump for (5), 500x200 7 – Focusing telescope, 1000x200 8 – Delay line for e-gun 8 4 6 5 3 1 2 7 M.Martyanov, CERN

9. Laser room air-conditioning principal (by Michele Battistin) Technical Room Laser Room SAS • CV technical room already quite small. Other solutions? • Access to CV technicians in the clean room for M&O. • Very dry air from surface -> comfort and electronics? 4.000 m3/h 30 Pa 15 Pa 0 Pa 4 m 14 m 2 m F M.Martyanov, CERN

10. CV first integration (by Michele Battistin) Air supply duct to the clean room Fresh air supply from surface Air extraction to TCV4 M.Martyanov, CERN

11. Laser Room – Integration 3D Model (by Frederic Galleazzi) M.Martyanov, CERN

12. Laser Room – Integration 3D Model (by Frederic Galleazzi) M.Martyanov, CERN

13. TT41 – Laser Beam – Civil Engineering (by Frederic Galleazzi) Vacuum shutter Vacuum pump Laser shutter Safety laser shutter M.Martyanov, CERN

14. Mirror Chambers Preliminary Design (by Nicolas Chritin) M.Martyanov, CERN

15. Laser and p+ merging Laser beam is not centered on the mirror in horizontal plane, but centered in vertical. The gap between beams is 21-6-13=2mm The gap between proton beam and a mirror is 1mm Footprint of the laser beam on the mirror 37=26sqrt(2) 50 26 37 Mirror 50, S=12 Fused silica Laser beam 26 Beams separation 21mm Towards the plasma Proton beam 12 p+ from SPS M.Martyanov, CERN

16. Laser Beam Size Downstream Merging (not to scale) Be-window for p+ Experimental area Additional laser shutters Mirror 50, S=12 Fused silica Plasma cell Beams separation 21mm 26 Fast valves Laser dump p+ from SPS Proton beam 12 20m 10m 20m Laser beam 26 @ merging Laser Safety Shutter M.Martyanov, CERN

17. Laser installation in laser room M.Martyanov, CERN

18. Laser installation in p-tunnel and in e-gun room M.Martyanov, CERN

19. Thank you! M.Martyanov, CERN

20. M.Martyanov, CERN

21. Laser room air-conditioning principal (our proposal) 4.000 m3/h Technical Room Laser Room SAS • CV technical room already quite small. Other solutions? • Makeitevensmaller ! • Access to CV technicians in the clean room for M&O • Assume itis a rare event ! • Very dry air from surface -> comfort and electronics? • Poor comfort (manageable), for electronics – to be considered 30 Pa 15 Pa 0 Pa 3 m 2 m ! 15 m F M.Martyanov, CERN

22. Focusing geometry, 40 meters Simple propagation of a super-Gaussian beam, no plasma Very smooth focusing Max 100 mJ Full energy focusing option Max 450 mJ Attenuated energy option Max 280 mJ Plasma here Last turning mirror

23. Focusing geometry, 40 meters Attenuated energy option, Super-Gaussian beam ionizing plasma, 100mJ pulse Ionization ratio in plasma dE = -30mJ