1. J. Corlett. June 16, 2006 A Future Light Source for LBNL Facility Vision and R&D plan John Corlett ALS Scientific Advisory Committee Meeting June 16, 2006

2. J. Corlett. June 16, 2006 Storage rings Energy recovery linac (ERL) Free electron laser (FEL) Laser wakefield accelerator Optical manipulation of electron beams Performance metrics Wavelength range Average and peak flux Average and peak brightness Pulse repetition rate Temporal coherence Spatial coherence Pulse duration Synchronization Tunability # beamlines Beam stability … A variety of synchrotron radiation source concepts to pursue Future generations of light sources will likely utilize novel techniques for producing photons tailored to application needs Different operating modes Work with users to define performance parameters

3. J. Corlett. June 16, 2006 Evolution of light sources - coherence offers next orders magnitude improvement Dominates if  z < Free Electron Laser (FEL) –Enhance coherence at shorter wavelengths by modulation of the charge within a bunch –PLUS optical manipulations Control of pulse duration Temporal coherence Harmonic generation of shorter wavelengths Precise synchronization Shorter gain length

4. J. Corlett. June 16, 2006 Vision for future light source at LBNL - a high rep-rate, flexible FEL facility Multiple independent beamlines up to ~100 kHz rep rate Low-emittance, high rep-rate gun 2-3 GeV CW superconducting linac Beam conditioning Beam distribution Complementary to ALS & LCLS Wavelength: ~200 nm to 1 nm Peak flux:10 10 -10 12 ph/pulse Short pulse:10-100 fs or 100 as Narrow bandwidth: ∆ / ~10 -5 Independent tuned FELs: Wavelength Pulse duration Polarization FEL configuration: SASE Seeded long pulse short pulse

5. J. Corlett. June 16, 2006 50 m Bevatron site ALS N

6. J. Corlett. June 16, 2006 50 m Injector Beam switchyard FEL farm Beamlines & experimental hall ALS N

7. J. Corlett. June 16, 2006 Comparison of seeded and SASE characteristics Electron beam is 1.5 GeV, energy spread 100 keV, 250 A current, 0.25 micron emittance; laser seed is 100 kW at 32 nm; undulator period 1 cm SASE, 20 m undulator 25 fs seed, 30 m undulator 500 fs seed, 30 m undulator Spectrum Pulse profile

8. J. Corlett. June 16, 2006 Dispersive section introduces bunching Bunched beam radiates strongly at harmonic in a downstream undulator resonant at 0 /n, nn -n  phase energy --  Input Output e - beam phase space: Laser modulates e-beam energy High-gain harmonic generation (HGHG) L.-H. Yu et al, Science 289 932-934 (2000) L.-H. Yu et al, Phys. Rev. Let. Vol 91, No. 7, (2003) modulator radiator dispersive chicane laser pulse e - bunch

9. J. Corlett. June 16, 2006 Optical manipulation 1 - ESASE Bunching Acceleration SASE Modulation A. A. Zholents, Phys. Rev. ST Accel. Beams 8, 040701 (2005) Precise synchronization of the x-ray output with the modulating laser Variable output pulse train duration by adjusting the modulating laser pulse Capability to produce a solitary ~100-attosecond duration x-ray pulse Increased peak output power Shorter x-ray undulator length to achieve saturation Peak current, I/I 0 z / L 20-25 kA

10. J. Corlett. June 16, 2006 Optical manipulation 2 - attosecond pulses Attosecond x-ray pulse using energy modulation with two lasers Energy modulation with two lasers (1.2, 1.6 µm) 1.5Å output pulse A.Zholents, W.M. Fawley, Phys. Rev. Lett. 92, 224801 (2004) A.Zholents, G. Penn, Phys. Rev. ST Accel. Beams 8, 050704 (2005) ~ 100 as

11. J. Corlett. June 16, 2006 Performance goals

12. J. Corlett. June 16, 2006 Performance comparisons Short pulse mode High resolution mode 0.0001 Attosecond mode LBNL FEL facility ALS Top-off

13. J. Corlett. June 16, 2006 Electron beam energy  High gradient accelerator Electron beam emittance  High brightness gun, minimize emittance growth in accelerator High gradient accelerator Manipulate and condition beam for FEL process Peak current  peak Bunch compression, minimize distortion from acceleration and longitudinal wakefield Energy spread   High brightness gun, minimize distortion from longitudinal wakefield Power/ undulator length R&D to address FEL performance (& cost) drivers

14. J. Corlett. June 16, 2006 Emittance sensitivity - cost effective to use low emittance beams x =1 nm, I peak =250 A,  E =100 keV

15. J. Corlett. June 16, 2006 Critical systems Low emittance, high rep rate source High gradient CW superconducting accelerator Advanced undulators and FEL radiators Bunch manipulation and conditioning Beam switching and transport

16. J. Corlett. June 16, 2006 R&D plan outline - (1) low emittance, high rep rate electron gun Low emittance, high quantum efficiency cathodes Photocathode laser systems Laser Cathode RF field Low emittance, high rep rate gun Electron beam

17. J. Corlett. June 16, 2006 R&D plan outline - (2) CW SCRF cryomodules from Stanford FEL & bunch manipulations High gradient CW accelerator Develop robust high gradient SCRF Collaborate with Cornell, J-Lab, etc Re-locate Stanford FEL? 40 MeV TESLA cavities 10 MV/m CW mode Electron beam emittance control and manipulations

18. J. Corlett. June 16, 2006 R&D plan outline - (3) accelerator physics and modeling Detailed computer modeling of the electron beam in all stages of the accelerator Highly parallelized code development Emittance compensation Design of transport optics Design of beam switchyard Design experimental program to demonstrate high rep rate low emittance beams SASE / Seeded / Cascade / Attosecond … FEL configurations LBNL expertise exists in the AFRD division

19. J. Corlett. June 16, 2006 Timeline July/August 2006 Present vision and R&D plan to DOE FY’07 Begin R&D studies LDRD support and some DOE funding FY’08-FY’12 Vigorous R&D program Cathodes, gun, lasers, emittance control, beam switchyard, superconducting RF, FELs FY’09 - CD0 FY’11-12 opportunity for construction project Following successful operations of LCLS and peak of NSLSII spend

20. J. Corlett. June 16, 2006