1. Laser Arm for Photo-injector Mikhail Martyanov, Valentin Fedosseev, Christoph Hessler AWAKE PEB meeting 07.11.2014, CERN

2. “2.5 mJ” “25 mJ” splitter mechanical pulse selector 25 mJ 650 mJ Amplifier atten Vacuum compressor Compressor THG atten UV to e-gun to plasma splitter mechanical pulse selector 2.5 mJ 650 mJ Amplifier atten Vacuum compressor Compressor THG atten UV to e-gun to plasma Budgetary options for e-gun arm

3. 650 mJ Amplifier atten Vacuum compressor Compressor THG splitter mechanical pulse selector 2.5 mJ 25 mJ Amplifier atten Option “Independency” for e-gun arm “+25 mJ” OptionWhat to buy “2.5 mJ”mechanical pulse selector, attenuator “25 mJ”mechanical pulse selector, attenuator, splitter “+25 mJ”mechanical pulse selector, attenuator, 25mJ amplifier

4. “300 fs” SHG BBO 0.6 mm 780(o)+780(o)=390(e) Zero-order dual WP, @780nm, /2@390nm 780nm horizontal 390nm vertical SHG BBO 0.4 mm 780(o)+390(o)=260(e) 260nm vertical 780nm horizontal 390nm vertical Harmonic separator 780nm horizontal 390nm horizontal “10 ps chirped” SHG BBO 0.2 mm 780(o)+780(o)=390(e) GVM compensator ~1mm Silica / Calcite Zero-order dual WP, @780nm, /2@390nm 780nm horizontal 390nm vertical 780nm horizontal 390nm vertical SHG BBO 0.1 mm 780(o)+390(o)=260(e) 260nm vertical 780nm horizontal 390nm vertical Harmonic separator 780nm horizontal 390nm horizontal 60  80 fs delay 780 w.r.t 390 Third Harmonic Generation (THG) Options EKSMA Optics AMPLITUDE Technologies

5. EKSMA OpticsEUR /2 zero-order WP, 780 nm 310 SHG BBO 20 x 20 x 0.2 mm2900780(o)+780(o)=390(e) SHG BBO 10 x 10 x 0.6 mm660For “10ps chirped” GVM compensator (Silica / Calcite / BBO …)~500 Zero-order dual WP,  17mm 410 THG BBO 20 x 20 x 0.1 mm2900780(o)+390(o)=260(e) THG BBO 10 x 10 x 0.4 mm660For “10ps chirped” Harmonic separation mirror, HR 260nm, HT 780+390nm,  25 x 3 mm 175 Mounts~1000 /2 zero-order WP, 260 nm 345 Total9860 Spare optics8685 Third Harmonic Generation (THG) Options

7. “300 fs” Chirped THG scheme 3D-simulation Output, I k (x, y=0, t) 780 nm390 nm260 nm

9. “10 ps” Chirped THG scheme 3D-simulation Output, I k (x, y=0, t) 780 nm390 nm260 nm

10. UV Stretcher (if needed) Transmission UV diffraction gratings 50 x 50 mm 1200 grooves / mm, 26.7  blaze angle 100 fs -> 10 ps L = 350 cm !!! 7+ meters delay L, gratings base UV stretcher layout Gratings available from EDMUND / OPTOMETRICS / SHIMADZU … Estimated stretcher price ~ 5000 EUR

11. Summary For a short bunch operation (“0.3 ps” option) -THG easy and straight-forward -Any bunch charge can be produced -No need for a “25 mJ Amplifier”, 2.5 mJ available now is enough For a long bunch operation (“10 ps” option) -For the ultimate 1nC case with Cu-cathode a good THG efficiency is required -Robust THG scheme simulation shows promising results: 2.2mJ UV from 25 mJ IR -“25 mJ Amplifer” is needed -For lower charges (or with Cs 2 Te cathode) existing 2.5 mJ output might be enough -UV stretcher is technically feasible and relatively cheap -No need for UV stretcher if chirped THG works well (can be easily tested at MPI)

12. Laser Requirements Table OptionCu-cathodeCs2Te-cathode 0.3 ps, 0.1 nC2.5 mJX 10 ps, 0.2 nC25 mJ Amplifier or 2.5 mJ 2.5 mJ 10 ps, 1nC25 mJ Amplifier2.5 mJ -Robust THG scheme proposed, to be tested for chirped 10ps -UV stretcher probably is not needed