CERN AWAKE Project Status
Edda Gschwendtner
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Outline
• Introduction• Project organization• AWAKE at CNGS• AWAKE at West Area• Bunch Compression• Other issues• Summary
E. Gschwendtner, ENTM, 20/11/2012
Introduction
AWAKE: A Proton Driven Plasma Wakefield Acceleration Experiment
Proof-of principle demonstration experiment proposed at SPS:– first beam-driven wakefield acceleration experiment in Europe– the first Proton-Driven PWA experiment worldwide.
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Introduction
June 2012: Official CERN AWAKE project : project-budgetmandate sent by S. Myers to CERN departments
produce parts of CDR under CERN responsibilityCDR includes detailed budget, CERN manpower and schedule plans for
design, construction, installation and commissioning.
Deliverables: End 2012: preliminary report summarizing the ongoing study to the A&T sector Management
Q1 2013: Conceptual Design Report to the A&T sector Management and the SPSC.
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Proton Driven Plasma Wakefield Acceleration
E. Gschwendtner, ENTM, 20/11/2012
Proton beam: drive beam (12cm)modulated in micro-bunches (1mm) after ~several metersdrives the axial electric field
Laser pulse: ionization of plasma and seeding of bunch-modulation
Electron beam: accelerated beaminjected off-axis some meters downstream along the plasma-cell, merges with the proton bunch once the modulation is developed.
Particle-in-cell simulations predict acceleration of injected electrons to beyond 1 GeV.
laser pulseproton bunch
gasPlasmaElectron bunchPlasma cell (10m)
Produce an accelerator with mm (or less) scale ‘cavities’
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AWAKE Physics and R&D Program• Measure bunch-modulation of the proton beam.• Learn in detail about the modulation process through comparisons of data/simulations. • Use a wide variety of diagnostics (transition radiation, direct measurement of fields, spectrometer,
…) to understand the process in detail.• Vary a number of parameters (density, electron injection point, …) to learn dependence on
parameters.• Try out compressed proton bunch to understand scaling with proton bunch length higher
gradients expected.• Measure parameters of accelerated electron bunch (energy spread , transverse emittance, …) and
find dependence on parameters compare to simulations
• Use the knowledge we gain to design a new set of experiments leading to real collider application.
• In parallel: continue studying producing short, high-energy proton bunches.
Time-scale proposed by collaboration: • End 2014: Demonstrate 1% uniformity and complete operational 10m plasma cell(s) ready for beam in 2015
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AWAKE Collaboration25 institutes: Germany, UK, Portugal, USA, France, India, China, Norway, USA
• Spokesperson: Allen Caldwell, MPI• Deputy spokesperson: Matthew Wing, UCL
• Experimental coordinator: Patric Muggli, MPI– Plasma cell, electron diagnostics, optical diagnostics,– Electron source
• Simulations coordinator: Konstantin Lotov, Budker INP– Proton/electron beam in plasma cell
• Accelerator coordinator: Edda Gschwendtner, CERN– CERN AWAKE Project Leader See next slide
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CERN AWAKE Project Structure
Radiation Protection: Helmut VinckeCivil Engineering: John OsborneGeneral Safety and Environment: Andre Jorge HenriquesGeneral Services: CV, EL, access, storage, handling
WP3: Primary beam-linesChiara Bracco
CERN AWAKE ProjectProject leader: Edda Gschwendtner
Deputy: Chiara Bracco
WP4: Experimental AreaEdda Gschwendtner
WP2: SPS beamElena Chapochnikova
WP1: Project ManagementEdda Gschwendtner
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A& T sector management:Engineering, Beams, Technology Departments
Injectors and Experimental Facilities Committee (IEFC)
Mandate of CERN AWAKE Project• Identify the best site (West Area or CNGS) for installation of the facility on the SPS by carrying out a
study covering:– The design of the proton beam-line from the SPS to the entry point of the plasma cell, to meet the required
parameters.– The design of the downstream beam-line from the plasma cell to the beam dump. – The design the common beam-line for the proton, electron and laser light beam at the entry into the plasma
cell. Specification of the parameters for these incoming beams. – The design of the experimental area (envelope) considering layout optimization of all components in the area. – The study of access possibilities and assess radiation and safety aspects. – The study of the general infrastructures (Civil Engineering, Access, CV, EL, transport, handling, control).– The physics program that could be carried out on each site. – The comparison of the cost and of the schedule of the alternative sites.
• Based on the study, recommend a site for the facility and deliver the chapters, covering the beam line, the experimental area and all interfaces and services at CERN, in the conceptual design report (CDR) of the AWAKE CERN facility. The CDR should include the points mentioned in the section above plus the following information:– Specification of the baseline beam parameters to be used for the design.– Predictions of measurable quantities in the diagnostic instrumentation.– Specification of diagnostic instrumentation in the experimental area.– Design and interface with the electron beam up to the plasma cell. – Study all interfaces between the different systems (plasma cell, electron beam, proton beam, laser…) – Evaluation of time scale and costs of all items at a level needed for the CDR.– Evaluate dismantling feasibility and cost.
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Proton Beam Specifications
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Parameter Nominal
Beam Energy 450 GeV
Bunch intensity 3×1011 p
Number of bunches 1
Repetition rate 0.03 Hz
Transverse norm. emittance 3.3-3.5 mm
Transverse beam size (at b*=5m)
0.2 mm
Angle accuracy <0.05 mrad
Pointing accuracy <0.5 mm
Energy spread 0.34% (rms)
Bunch length 12 cm
Energy in bunch 21 kJ
Parameter Nominal
Number of run-periods/year 4
Length of run-period 2 weeks
Total number of beam shots/year (100% efficiency)
162000
Total number of protons/year 4.86×1016 p
Relaxed proton beam requirements for the first years of run However, long-term goal is to get shorter longitudinal beams
Bunch-compression Continue MDs!
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Beam Specifications
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Parameter Value
Beam Energy 5 or 10 or 20 MeV
Bunch intensity 108 electrons
Bunch length 0.165mm<l<1mm
Repetition rate 0.03 Hz
Transverse norm. emittance
< 25 mm mrad
Transverse beam size (at beta*=?m)
??
Angle(mrad) ~5-20 mrad
Electron beam specifications
Laser:30fs, 800nm, ~TW.
R & D facility: frequent access to plasma cell, laser, etc… needed.
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Experimental Layout
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Plasma-cellProton beam dump
RF gun
Laser
Laser dump
OTRStreak camera
CTREO diagnostic
e- spectrometer
e-
SPSprotons
~3m
10m 15m20m >10m
10m
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West Area
CNGS
SPS
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Facility Site I: CNGS
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CNGS
CNGS is a running facility since 2006 at the desired beam parameters.+ Underground facility!
Proton beam and secondary beam-line fully equipped and running All services (CV, EL, access, …) in place and used
CNGS Parameters
Proton beam energy from SPS 400 GeV/c
Cycle repetition rate 0.17 Hz
Number of extractions/cycle 2
Protons per cycle 2x2.4E13
Proton pulse length 10.5 ms
Beam power (max.) 510 kW
Beam size at target ( )s 0.5mm
Protons/year 4.5E19
To compare with AWAKE:
0.03 Hz cycle repetition rate3E11 protons per cycle4.9E16 protons/year
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CNGS – AWAKE Facility
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Target Horn
TSG41
Storage gallery
(120 m)
Proton beam line TT41 Junction chamber Target chamber
Access Gallery
Service gallery
AWAKE experimental facility at CNGS upstream the CNGS target: Separate CNGS target area from upstream area:
Add shielding wall Allows to cool-down target/horn Keep flexibility in case CNGS would restart
Use hadron stop as beam dump
CNGS – Proton Beam Line• Existing SPS extraction, no changes needed.• Magnets exist• Beam instrumentation exists (some modifications/cabling)
• Minor changes at the end of the proton-line for:– New final focusing– Interface between Laser and proton beam
Present Layout
New Layout
1 QTG removed
2 QTLD
X
1 QTLD + 1 QTS
3 QTLF
X1 QTS removed
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Chiara Bracco
CNGS - Laser Integration with p-Beam
Last QTL
Last MBG
Laser
Proton Beam
• Laser mirror: o 20 m upstream entrance plasma cello 12.5 m upstream of last MBG 30.7 mm offset between proton and laser beam at mirror needed clearance: 23mm OK!
• Aperture along the line: OK No conflict with integration studies!
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Chiara Bracco
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Laser for seeding TI:sapphire
Plasma Cell
RF gun+
space for handling
Power supply laser
RF Gun cooling
Junction laser system and proton
OTR screen
Primary pump laser
Optic table
Klystron
Power supply
Laserdiagnostic
SAS
LaserRF Gun
Shielding wall
DIPOLE
SAS
El. Spect. magnet
Optic table
camera
CNGS – AWAKE Facility
Ans PardonsDamien BrethouxVincent Clerc
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CNGS – Infrastructure• Survey:
– 1-2 months, ~60kCHF
• Access, fire, safety system:– Exists, modifications needed– Existing access could be moved down the tunnel to create ‘control room area’
in access gallery.
• Electricity– Infrastructure exists, modification needed
• Cooling and Ventilation– Infrastructure exists, modifications needed:
• E.g.: overpressure and temperature controlled service gallery
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With today’s beam-line and experimental area design (+needs from equipment) start studies on services infrastructure estimates expected by end Dec 2012!
Dominique MissiaenRui Nunes, Silvia GrauDavide BozziniMichele Battistin
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CNGS – RP Considerations• Control room in CNGS access gallery possible, but needs
– Dose rate due to prompt radiation low enough– Fresh air, no radioactive air from experiment– Appropriate access system– Assess beam loss in upstream part of TT41.
• Beam is dumped on hadron stop No issue with prompt dose from muons
• Installation of shielding wall between AWAKE experimental area and CNGS target area reduces dose rate inside the AWAKE area.– Assume that dose rate in AWAKE experimental area comes from CNGS target station and to lower level
from surrounding activated wall.– First estimate for required wall thickness: 80cm of concrete
• Collimator upstream the target must be remotely removed.
• Civil engineering (drilling holes) – Activation level to be analyzed and precautions defined.
• Tritium issue:– Evaporator to be installed independently of AWAKE facility, so OK.
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Helmut Vincke
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Facility Site II: West Area
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TT61
TT4TT5
Beam from TCC6 - SPS
AWAKE
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Proposed in LOI, 2011
West Area today:Proton beam line TT61: ~emptyTT4 and TT5: storage area for (radioactive) magnets Needed during LS1
Until 2004: West Area used as experimental beam facility.
West Area – Proton Beam Line
• Magnets needed:– 8 MBS– 17 vertical bending magnets– 2 horizontal bending magnets– 25 Quads (18 in TT61 + 7 final focusing)
• Power Converters needed: – ~ 10 units
• Beam instrumentation needed:– ~15 BPMs– ~10 BTVs
TT60 from SPS
TI 2 to LHC
HiRadMat facility
TT61 tunnel to west hall
HiRadMat primary beam line (TT66)
Modification of TT66
8 new switching magnets
Time estimate:– New magnets and PC design: 3
years– Re-use existing equipment
(inventory needed) cabling anyhow needed start only after LS1
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Chiara Bracco
West Area - Radiation Constraints
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Consequences to meet RP constraints: 1. For a surface installation of dump: bend beam by about 10°or2. Dump impact at ~2 m underground: tilt beam by 2°.
• Build a beam-trench in TT4/TT5 civil engineering• 300 GeV beam to fit into TT61 and TT4/TT5
+3. To cope with beam losses: shielding at surface to forward and lateral direction.
beam on dump: particular problem from muonsMake sure that radiation levels from muons are below RP optimization criteria:
CERN fence
West hall
100 mSv/year
10 mSv/year
Muon dose rate expected for beam@dump impact at 2 m below surface at a bending angle of 2 degree (no losses at beam line considered).
CERN FENCE
• 1E-3 mSv/h (contours in picture) correlates to less than 10 mSv/year. Compliant with RP optimization limit for public for ultimate and nominal beam.
OK
• Radiological situation inside West Area to be further investigated (size of radiological classified areas, additional shielding on surface, air activation…)• New situation at 300 GeV with a beam impact at -1.4m to be studied.
West Area – RP IssuesHelmut Vincke
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West Area - Civil Engineering Aspects
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Trench work concentrate on TT4/TT5
3.5m x 3.5m trench, 100m long~1.1MCHF, ~10months
66 kV power line
18kV
– Technical gallery! • 18kV & 66kV power lines:
backbone of the CERN grid• Installation until end 2012
Dig trench only in TT5
TT4TT5
John Osborne, Antoine Kosmicki
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West Area – Proton Beam Line
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dump
~2° angleDump depth: 1.4 m
TT61TT4TT5
technical gallery
+ Old Line•New Line- Tunnel
m
m
To respect all geometric and RP constraints: reduce beam energy to 300 GeV OK for experiment b = 3.7 m = 200 s mm: feasible!
Chiara Bracco
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West Area – Experimental Area
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Ans PardonsDamien BrethouxVincent Clerc
TT4
TT5
West Area – Experimental Area
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Laser for seeding TI:sapphire
RF gun+
space for handling
Power supply laser
RF Gun cooling
Primary pump laser
Laser RF gun
Power supply
Laser diagnostic
SASclean area
Klystron
SASShielding
Hi Rad MAT
Rack
Ans PardonsDamien BrethouxVincent Clerc
West Area – Experimental Area
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Plasma Cell
El. Spect. DetectorEl. Spect. Magnet
Sec.Beam.Diag
Optic table
Optic table
Rack
OTR screen
OTR screen
Pump turbo plasma
Camera
Optic table
DumpGallery
Junction laser system and proton
Entry point 1.20m depth
Distance floor / beam 600 mm
Gallery
Tunn
el h
all E
3
Gallery
Ans PardonsDamien BrethouxVincent Clerc
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West Area – Beam Dump
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Various materials were studied in terms of temperature behavior: Light materials (e.g. Carbon): significantly lower temperature increase than heavy materials. But higher hadronic interaction length: higher muon production
Simulations of H. Vincke: for carbon used as core material significant increase in muon dose at a distance of 600m from beam dump at CERN fence (different for iron as core material). Results qualitatively confirmed by simulations from the FLUKA team. Further input from RP: carbon would be ideal for activation issues, however, high muon production might be show stopper for the current design.
Vasilis Vlachoudis, Thanasis Manousos
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West Area - Access System
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Rui Nunes
TT61 Access Point
Existing/new beam
line
nTOFAccess Point
Access gallery for nTOF/TT61
Shielding/Civil Eng. Must leave path for
access to nTOF
West Area:- Need new access system of ‘primary area type’ (higher level of risk exposure and radiation
classfication)- Turnstile and material access door needed, passive beam stopper, - Interlock system shared with HiRadMat and LHC (to be modified)- De-coupled from nTOF area
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West Area – Infrastructure• Survey :
– 5 months, ~140kCHF
• Electricity– Primary substation is close (200m)– Existing infrastructure old– A lot must be refurbished, renewed…
• Cooling and Ventilation- Pumping system, cooling towers, piping connections
- need refurbishment, redoing, some of them could maybe be used- Separate ventilation systems for proton beam-line, experimental area and dump
• Safety, Fire system – To be studied.
E. Gschwendtner, ENTM, 20/11/2012
With today’s beam-line and experimental area design (+needs from equipment) start studies on services infrastructure estimates expected by end Dec 2012!
Dominique MissiaenDavide BozziniMichele BattistinSilvia Grau
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CNGS vs West Area – Incomplete!
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CNGS West Area
Proton beam line magnets + Exist - To be done
Beam instrumentation + Exist - To be done
Prompt dose issues(muon dose)
+ OK - Consequences on shielding, West Area classification on beam energy, and/or limited number of extractions!
Other radiation issues - Target chamber must be shielded: Target, horns. Need long cool-down to remove.
- Beam losses: need forward and lateral shielding
Civil engineering -+ Drill holes only. - Dig trench in TT5- Technical gallery btw. TT4/TT5
Size of experimental area -+ OK, but tight + OK
Control room - Inside tunnel or ECA4 - New building needed
Access + Access system exists, - long distance to experimental area make ‘control room area’ in access gallery
- New access system
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CNGS vs West Area – Incomplete!
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CNGS West Area
Electricity + Exists - needs some modifications
- To be done, refurbished, renewed,…
Cooling, ventilation + Exists- needs some modifications
- To be done refurbished, renewed,…
Storage issues + use storage gallery - TT4/TT5 is radioactive material storage area: full with stored magnets, etc… area needed in LS1. build new storage building.
Beam dump + OK, exists - Must be newly built - lot of shielding needed- Optimization of dump design!
Vacuum system - Exist for proton beam line - To be done
Survey - New network points in experimental area. 1-2 months
- New network point along beam line and experimental area, fiducials, … 5 months
Additional Safety Measures
- Laser - Klystron- …
- Laser- Klystron- ….
Further Studies Needed!
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Bunch Compression Studies in SPS
2 MDs: Bunch-rotation tests: 11 July 2012, 30 October 2012
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T. Argyropoulos, H. Bartosik, T. Bohl, J. Esteban Muller, A. Petrenko, G. Rumolo, E. Shaposhnikova,H. Timko
Maximum axial electric field depends on bunch-length of drive beam! Strong interest to study bunch compression (Today SPS beam is 12cm long!)
Studies ongoing
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Possible Collaboration with CERNElectron source: • Eventually UK did not get the funding to build the electron source.• AWAKE Collaboration tries to find other ways
– EU synergy grant (deadline January 2013)– China
• Use PHIN injector as electron source?– To be clarified in next weeks.
Laser:• Idea is that the laser for the electron source together with the laser for the plasma-
source is provided by the experimental groups. – Will be tested with the plasma cell at institutes.– Must be well synchronized. – Collaboration with CERN useful though for installation, interface, safety,…
Diagnostics:• Experimental groups provide diagnostics instrumentation, but CERN BE-BI very
interested to collaborateVacuum system:• Valves, …
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SummaryProton Driven Plasma Wakefield Acceleration is a unique accelerator R&D experiment at CERN.
Studies for the CERN AWAKE facility are advancing well– SPS beam studies– proton beam-line design– experimental area Enough input to start infrastructure studies and design
From preliminary studies– CNGS: Beam possible in 2015, when:
• Only reusing proton beam-line an no major modifications are needed (e.g. dismantling of CNGS target, horns,…)
• Underground area, so less RP issues– West Area: Beam not available before 2017:
• New magnets, build new storage area, trench (civil engineering), new service installations,…• Surface area RP issues
Collaboration with CERN for specific issues
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Additional slides
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40E. Gschwendtner, ENTM, 20/11/2012
2.65m1.65m
TAG41
1.6m
2.6m
TSG40
5m
3.2mTSG41
1.75m
2.86m
TT41
TT41
1.55m
2.55m
TCV4
TCC4
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Introduction
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Driving force: Space charge of drive beam displaces plasma electrons.Restoring force: Plasma ions exert restoring force.
++++++++++++++ ++++++++++++++++
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------ -- -- ---- - - - - - --
---- - -- - - - --- -
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- -- - - - - -
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+ + + + + + + + + + ++ + + + + + + + + + + + + + ++ + + + + + + + + + + + + + ++ + + + + + + + + + + + + + +-
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Ez
Proton beam
plasma wavelength lp =1mm, (for typical plasma density of np = 1015cm-3 )
Maximal axial electric field: Ez,max = Nprotons/bunch
sz (rms bunch length) also drive beam sz of 1mm
But: SPS beam: rms length of sz~12cm Would need bunch-compression OR Modulate long SPS bunch to produce a series of ‘micro-bunches’ in a plasma with a
spacing of plasma wavelength lp. Strong self-modulation effect of proton beam due to transverse wakefield in plasma Starts from any perturbation and grows exponentially until fully modulated. Start of bunch-modulation in controlled way: strong laser pulse