AWAKE Beam Lines AWAKE Review 28 November 2019

AWAKE Beam Lines AWAKE Review, 28 November 2019 F. Velotti, B. Goddard, R. Ramjiawan

Motivation of equipment studies for Run 2 • AWAKE Run 2 foresees a very different accelerating zone: • We will now go to a 2 plasma-cell structure with the requirements of 2 electron beams delivered in 2 different locations with 2 sources • The changes in the plasma cell layout require modifications of the TT 41 (p+) and TT 43 (e-) lines • • Reorganisation of final chicane and focusing of TT 41 New geometry for the existing electron line Optics re-matching and instrumentation modifications for both lines Additional electron line for witness bunch • The main goal of AWAKE Run 2 is to achieve acceleration of the witness electron bunch preserving beam quality • Very tight beam requirements, at injection, have been given from the experiment and hence a completely new electron highenergy beam line is needed Modified present e - line SPS – TT 40 – TT 41 AWAKE Review, 28 November 2019 2

Current studies – challenges • New 165 Me. V electron beam line needed to transport accelerationwitness bunch at the entrance of the second plasma cell • Very challenging transverse and longitudinal parameters at injection into plasma: • Beam size at injection: 4 -7 um (5 um taken as baseline) • Bunch length 200 fs (RMS) same as from source! • Very tight to integrate it injection needs to happen in between the 2 plasma cells (~1 m between the cells) • Also, new electron source and line parallel to first plasma cell AWAKE Review, 28 November 2019 3

R. Ramjiawan Dogleg Four-dipole design Double achromat Two-dipole design • Current studies – electron line Rebecca Ramjiawan AWAKE Review, 28 November 2019 4 4

Timeline for beam lines study phase • Beam Lines CP in TE/ABT 0. 15 FTE and 1 post-doc (PJAS) from Oxford 2019 AWAKE Review, 28 November 2019 2020 5

Milestones for study phase • Study phase started 1/07/19 and will last until technical review mid/end-2020 • Main milestones identified (with assumption that parameters from experiments and source frozen): • Propose geometry and optics changes needed for p+ line (September 19) • Done • Conclude studies on p+ line (end 2019) • On track • Define geometrical layout of new electron line (end 2019) • On track • Technical feasibility of new electron beam line (March 2020) • On track so far – this is fundamental for equipment design and procurement timeline • Define layout changes needed for present electron line (June 2020) • Not started • Freeze beam line layouts (AWAKE review, Q 3 -2020) AWAKE Review, 28 November 2019 6

Conclusions • The AWAKE Run 2 experimental layout demands for upgrades of the present proton and electron line to satisfy the experimental requests • The CP in TE/ABT includes 0. 15 FTE and one post-doc • Clear timeline for the study agreed on between project and CPL • Very clear milestones identified and inline with project schedule • Studies on the modification needed for the p+ line almost completed as foreseen • Studies on the electron line started and first results very encouraging AWAKE Review, 28 November 2019 7

Backup AWAKE Review, 28 November 2019 8

Current studies – proton line • 2 options have been investigated • In both cases, the optics re-matching is feasible, although, for option 1, reduction of apertures and reduction of beam delivery accuracy (need to remove some instrumentation) • Option 2 is now used as baseline Option 1: keep CNGS target Option 2: remove CNGS target AWAKE Review, 28 November 2019 9

Current studies – proton line • Changes in bending angle • Chicane dipole angle reduced to 80% of existing value, to increase offset at laser merge-mirror to 33 mm. • Changes in element positions • The two dipoles at the end of the chicane and all the instrumentation afterwards have been shifted by +8 m. • Still to study • Optimise the location of beam instrumentation and quantify the beam stability and pointing accuracy achievable. R. Ramjiawan Parameters at plasma merge-point �� _�� =4. 900, �� _�� =0. 000, �� _�� =− 0. 000, �� _�� =0. 041, �� _�� =200. 6 μm, �� _�� =201. 0 μm Laser mirror AWAKE Review, 28 November 2019 10

Outline • Motivation of equipment studies for Run 2 • Timeline for beam lines study phase • Current studies • Proton line • Electron line • Milestones of studies • Conclusions AWAKE Review, 28 November 2019 11