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NLCTA Facility Capabilities. E. R. Colby 5/18/09. Ti:Sapphire Laser System. E163 Optical Microbuncher. Cl. 10,000 Clean Room. NLCTA Overview. ESB. Counting Room (b. 225). L-1 (SNS). X-3 (2-pack). E-163. RF PhotoInjector. Gun Spectrometer. 30 feet. Space available for experiments. - PowerPoint PPT Presentation
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NLCTA Facility Capabilities
E. R. Colby 5/18/09
NLCTA Overview
RF PhotoInjector
Ti:Sapphire LaserSystem
Next Linear Collider Test Accelerator
Cl. 10,000 Clean Room
Counting Room(b. 225)
E163 Optical Microbuncher
Gun Spectrometer
ESB
Next Linear Collider Test Accelerator
E-163
NLCTA capabilities:
* S-band Injector producing high-brightness 60 MeV beams (to ~100 pC); ultrashort, ultracold
* (4) x-band rf stations and >300 MeV of installed structures
* (2) L-band rf stations
* Skilled operations group with significant in-house controls capability
S X-0 X-1 X-2
X-3
(2-pack)
L-1
(SNS)
Space available for experiments
20 feet
30 feet
Capabilities• Electron Beam (from injector)
– 60 MeV, 5 pC, p/p≤10-4, ~1.5x1.5 mm-mradtpsec– Beamline & laser pulse optimized for very low energy spread, short pulse
operation• Laser Beams
– 10 GW-class Ti:Sapphire system (800nm, 2 mJ)• KDP/BBO Tripler for photocathode (266nm, 0.16 mJ)
– Active and passive stabilization techniques– 5 GW-class Ti:Sapphire system (800nm, 1 mJ)
• 100 MW-class OPA (1000-3000 nm, 80-20 J)• 5 MW-class DFG-OPA (3000-10,000 nm, 1-3 J)
• Precision Diagnostics– Picosecond-class direct timing diagnostics
• Micron-resolution beam diagnostics– Femtosecond-class indirect timing diagnostics– Picocoulomb-class beam diagnostics
• BPMS, Profile screens, Cerenkov Radiator, Spectrometer– A range of laser diagnostics, including autocorrelators, crosscorrelators, profilometers,
etc.
NLCTA Laser & LSS
Modest changes required to support EEHG Experiment:
• Install evacuated transport line (vacuum components in-hand; pumping is in place)
• Install second laser safety shutter (no new logic; add second driver + shutter)
• Seek LSC approval for 1-3 micron operation in NLCTA vault and modify SOP
EEHG Experiment and Diagnostics are similar to the E-163 Attosecond Bunching Experiment
Experimental Parameters:• Electron beam
• γ = 127• Q ~ 5-10 pC• Δγ/= 0.05%• Energy Collimated• εN = 1.5 mm-mrad
• IFEL:• ¼+3+¼ period• 0.3 mJ/pulse laser• 100 micron focus• Z0 = 10 cm (after center of und.)• 2 ps FWHM • Gap 8mm
• Chicane 20 cm after undulator• Pellicle (Al on mylar) COTR foil
Attosecond Bunch Train Generation
First- and Second-Harmonic COTR Output as a function of Energy Modulation Depth (“bunching voltage”)
Left: First- and Second-Harmonic COTR output as a
function of temporal dispersion (R56)
Inferred Electron Pulse Train Structure
Bunching parameters: b1=0.52, b2=0.39
C. M. Sears, et al, “Production and Characterization of Attosecond Electron Bunch Trains“, Phys. Rev. ST-AB, 11, 061301, (2008).
800 nm 400 nm
400 nm 800 nm
=800 nm
Inferred Electron Beam Satellite Pulse
E
400 nm
800 nm
Q(t)
I(t)
Electron Beam Satellite!
Machine stability supports sub-picosecond class e/ experiments
e.g. This cross-correlation measurement of the electron bunch profile took 5 minutes.
Much of the visible spread is due to COTR intensity jitter (~Q2) rather than timing jitter
Preliminary Beam Quality Measurement at EEHG Experiment Location 20 pC, 60 MeV, Measured 4/13/09
• Dispersion measurement was not yet working in downstream linac! Horizontal emittance had significant residual dispersion contribution
• Beam at 60 MeV (drifting through all linac x-band structures)
EEHG Location
Measurement Locations
Summary• Existing NLCTA laser systems meet EEHG experimental
requirements– Modest extension of the LSS functionality required (shutter+driver)– Laser transport installation required (components in-hand)
• Existing NLCTA electron beam quality meets EEHG experimental requirements at 120 MeV, likely also at 60 MeV, with further machine studies.– Some additional beam diagnostics ahead of the EEHG experiment
would speed commissioning
• Sub-picosecond-class timing stability has been demonstrated• E-163 experience with near-IR e/ experiments is directly
relevant and provides significant leverage– Experience designing experiments and hardware in this low-charge sub-
psec regime– Wealth of advanced automated measurement software in LabVIEW and
Matlab