awake experiment
DESCRIPTION
Laser Beam Transport and Integration. AWAKE Collaboration meeting. Mikhail Martyanov Christoph Hessler CERN, EN-STI-LP Valentin Fedosseev CERN09-11.04.2014. AWAKE Experiment. Control room 1km. AWAKE gallery. e-gun room. Laser room. SAS. CV. e - beam. p + / e - - PowerPoint PPT PresentationTRANSCRIPT
Laser Beam Transport and Integration.
AWAKE Collaboration meeting.
Mikhail MartyanovChristoph Hessler CERN, EN-STI-LPValentin Fedosseev
CERN 09-11.04.2014
M.Martyanov, CERN 210.04.2014
AWAKE Experiment
Laser room
e-gun room
p+ beam
e- beam
laser beam
Laser safety shutters
Laser shutters
Fast valves
plasma
e- spectrometer
Laser dump
p+ / e-
diagnostics
CV
SAS
AWAKE gallery
Control room 1km
Laser / p+ merging point
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
10.04.2014
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 opticson the way
Rule of thumb (B<1):I[GW/cm2]L[cm]<36
10.04.2014
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 to merging 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.• 10-6 Torr “easily” achievable. Pellicle or differential pumping as an option to go better
10.04.2014
M.Martyanov, CERN 610.04.2014
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
1mcompressor
2 x 1 m
optical table
SAS
CVunits
4m 3m
0.9m
2 x 1 m
optical table
2.5 x 1 m
optical table
2.5 x 1 m
optical table
Arrangement in the Laser Room
Fore-vacuum laser transfer line for e-gun(on the ceiling)
10.04.2014
PP+ power supply600x600x(H)850
CCM rack700x800x(H)1400
~1m
M.Martyanov, CERN 8
1
6
53
4
2
8
7
Three optical tables: 2x1, 2.5x1, 2.5x1 m
1 – MENLO oscillator, 500x5002 – Stretcher, 1000x5003 – Regen / preamp, 1000x800 4 – Green pump for (3)5 – 600mJ amplifier, 1500x8006 – Green pump for (5), 500x2007 – Focusing telescope, 1000x2008 – Delay line for e-gun
Laser Arrangement on the Tables
10.04.2014
M.Martyanov, CERN 9
4.000 m3/h
F 30 Pa 15 Pa 0 Pa
Technical Room Laser Room SAS
4 m 14 m 2 m
• 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?
Laser room air-conditioning principal(by Michele Battistin)
10.04.2014
M.Martyanov, CERN 10
Fresh air supply from surface
Air supply duct to the clean
room
Air extraction to TCV4
CV first integration(by Michele Battistin)
10.04.2014
M.Martyanov, CERN 1110.04.2014
Laser Room – Integration 3D Model(by Frederic Galleazzi)
M.Martyanov, CERN 1210.04.2014
Laser Room – Integration 3D Model(by Frederic Galleazzi)
M.Martyanov, CERN 13
TT41 – Laser Beam – Civil Engineering(by Frederic Galleazzi)
10.04.2014
Safety laser shutter
Vacuum pump
Vacuum shutter
Laser shutter
M.Martyanov, CERN 14
Mirror Chambers Preliminary Design(by Nicolas Chritin)
10.04.2014
M.Martyanov, CERN 15
Laser beam is not centered on the mirrorin horizontal plane, but centered in vertical.
The gap between beams is 21-6-13=2mmThe gap between proton beam and a mirror is 1mm
50
2637
Footprintof the laser beam
on the mirror37=26sqrt(2)
Laser beam 26
Mirror 50, S=12Fused silica
Proton beam 12
Beams separation
21mm
Tow
ards
the
plas
ma
p+ from SPS
10.04.2014
Laser and p+ merging
M.Martyanov, CERN 1610.04.2014
Laser Beam Size Downstream Merging(not to scale)
Laser beam 26 @ merging
Mirror 50, S=12Fused silica
Proton beam 12
Beams separation
21mm
p+ from SPS
Plasma cell
20m 10m 20m
26
Additional laser shutters
Fast valves Laser dump
Be-window for p+Experimental area
Laser Safety Shutter
M.Martyanov, CERN 17
System To define / To doLaser room, SAS, CV 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, position has been definedAccess to laser room and p-tunnel
AWAKE access concept including Laser Access Modes to p-tunnel and e-gun room, safety shutters
Ti:Sa laser Laser arrangement on three tables to be defined by AMPLITUDE. Arrangement of chillers and electronics – to be definedControls and diagnostics are provided by AMPLITUDEDetailed specification is required
Vacuum pulse compressor and focusing telescope.
Who supply compressor chamber ?Vacuum agreed to be 1e-06mbar in the compressor
Transfer line to p-tunnelMerging point chamber
To be designed, work has been started
Transfer line to e-gunSeparate small compressor3rd harmonic generation
In fore-vacuum, to be designed
Laser installation in laser room
10.04.2014
M.Martyanov, CERN 18
System IssuesLaser beam in the p-tunnel Steady 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 timing measurementsOn demand or maintenance diagnostics:Auto-correlator, angular spectrometer, phase-front detector, etc.
Laser beam in the e-gun room(small compressor and 3rd harmonic generation are next to the gun)
Steady diagnostics:Virtual cathode CCD, UV energy meter, some IR signal coupled to a fiber for rough timing measurementOn 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 installation in p-tunneland in e-gun room
10.04.2014
M.Martyanov, CERN 19
Thank you!
10.04.2014
M.Martyanov, CERN 2010.04.2014
M.Martyanov, CERN 21
4.000 m3/h
F
30 Pa 15 Pa 0 Pa
Technical Room Laser Room SAS
2 m ! 15 m 3 m
• CV technical room already quite small. Other solutions?– Make it even smaller !
• Access to CV technicians in the clean room for M&O– Assume it is a rare event !
• Very dry air from surface -> comfort and electronics?– Poor comfort (manageable), for electronics – to be considered
Laser room air-conditioning principal(our proposal)
10.04.2014
Attenuated energy optionMax 280 mJ
Full energy focusing optionMax 450 mJ
z, m
r, m
m
Flux W [J/cm2], Ith = 1.7 TW/cm2, Wth = 0.2 J/cm2E0 = 100 mJ, Wmax = 1.54 J/cm2, Imax = 12.1 TW/cm2
0 10 20 30 40 50 60 70 80
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5 0
0.5
1
1.5
z, m
r, m
mFlux W [J/cm2], Ith = 1.7 TW/cm2, Wth = 0.2 J/cm2
E0 = 100 mJ, Wmax = 5.24 J/cm2, Imax = 41.0 TW/cm2
0 10 20 30 40 50 60 70 80
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
z, m
r, m
m
Flux W [J/cm2], Ith = 1.7 TW/cm2, W th = 0.2 J/cm2E0 = 100 mJ, Wmax = 10.07 J/cm2, Imax = 78.8 TW/cm2
0 10 20 30 40 50 60 70 80
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
1
2
3
4
5
6
7
8
9
10
Plasma hereLast turning mirror
Very smooth focusingMax 100 mJ
Focusing geometry, 40 meters
Simple propagation of a super-Gaussian beam, no plasma
z, m
r, m
m
Flux W [J/cm2], Ith = 1.7 TW/cm2, W th = 0.2 J/cm2E0 = 100 mJ, Wmax = 5.46 J/cm2, Imax = 50.1 TW/cm2
0 10 20 30 40 50 60 70 80
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
z, m
r, m
m
Flux W [J/cm2], Ith = 1.7 TW/cm2, Wth = 0.2 J/cm2E0 = 100 mJ, Wmax = 5.46 J/cm2, Imax = 50.1 TW/cm2
0 2 4 6 8 10
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
z, m
r, m
m
Ionization ratio P, Ith = 1.7 TW/cm2, W th = 0.2 J/cm2E0 = 100 mJ, Wmax = 5.46 J/cm2, Imax = 50.1 TW/cm2
0 2 4 6 8 10
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Focusing geometry, 40 metersAttenuated energy option, Super-Gaussian beam ionizing plasma, 100mJ pulse
Ionization ratio in plasmadE = -30mJ