Laser news AWAKE performance meeting

Overview There was a meeting on with the supplier of the laser system (AMPLITUDE) No new information on the laser system yet The placement of the optical compressor and the focusing telescope has to be defined before drilling the connection tunnel Availability of vacuum components for the compressor and telescope is under study Torr “easily” achievable. Pellicle or differential pumping as an option to go better Provocative: is Torr overestimated?

Some measurements of laser room with respect to merging point

SystemTo define / To do Laser room, equipped with a big SAS Air circulation, conditioning, humidity, filters, circuits (electrical, demineralized water, tap water, compressed air, control cables), safety (fire/smoke alarm), shutters, access etc. Connection tunnel  40cm Drilling, coordinates of laser beam to be defined Access to laser room and tunnelAWAKE access concept including Laser Access Modes to p-tunnel and e-gun room, safety shutters Ti:Sa laserArrangement in a squeezed room, max laser table width is 1m Chillers and electronics are below the tables or in the separate ventilated rack/cabinet or in the big SAS Vacuum pulse compressor and focusing telescope. HV (10 -6 Torr) or UHV (10 -8 Torr): pellicle or differential pumping Placement is not defined yet (->AMPLITUDE)! Placement in the laser room is a base-line In case of p-tunnel everything must fit between p-beam and wall, “dirty” environment in p-tunnel is not good for compressor/telescope installation and maintenance Transfer line to p-tunnel Merging point chamber HV UHV (only 2 mirrors, possibly without in-vacuum motors) Transfer line to e-gun Separate small compressor 3 rd harmonic generation In fore-vacuum Next to the gun Laser dedicated list of “Things to Do”: Laser Installation

Preliminary AWAKE access will be discussed preliminary on the dedicated meeting Courtesy of C.Hessler

SystemIssues Ti:Sa laserControls and diagnostics are provided by the supplier of the laser system (AMPLITUDE) Vacuum pulse compressor and focusing telescope Diagnostics are provided by the supplier Laser beam in the p-tunnelSteady diagnostics: Focused beam spot monitor (virtual plasma, the same long distance run); near field before merging mirror; screens before and after plasma tube sensitive to “both” beams (laser, electrons, protons) also equipped with fiber-coupling for rough timimg measurements On demand or maintenance diagnostics: Auto-correlator, angular spectrometer, phase-front detector, … Laser beam in the e-gun room (small compressor and 3 rd harmonic generation are next to the gun) Steady diagnostics: Virtual cathode CCD, UV energy meter, some IR signal coupled to a fiber for rough timimg measurement On demand or maintenance diagnostics: Auto-correlator, angular spectrometer, … Delay control between pulses: ionization and e-gun Delay line either on one of 2 beams, proper delay simulation required. Split after RegAmp was proposed by AMPLITUDE with 2.5mJ IR output for e-gun Laser dedicated list of “Things to Do”: Laser Operation

OTR or laser light -Imaging (lens system and CCD) -Capture and measure with PhD or streak-camera (coupling to a fiber or lens system) -Other techniques Alignment of 3 beams plasma p-beam laser-beam e-beam BPM

Alignment of 3 beams 3 beams (protons, electrons and laser) have to be align in space and time Transverse accuracy ~ 0.2mm Angular accuracy ~ 0.2mm / 10 m = 20  rad Timing electrons-laser ~ 100fs – alignment by response? Rough alignment is needed anyway Timing protons-laser ~ 10ps – alignment with fast PhD and scope possible, 1pJ of light is required. Streak-camera. For robust alignment of 3 beams we need an optical signal which comes from the same screen sensitive to 3 beams (the power of laser beam can be reduced for the measurements not to damage the screen)

Thank you