LCLS Project Overview What is the LCLS Transition

LCLS Project Overview • What is the LCLS ? • Transition from 3 rd generation light sources to xray free-electron lasers • The SASE principle and linac-driven free-electron lasers • Performance • Accomplishments • R&D and construction plan Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview What is the LCLS ? • • Single pass Free-Electron Lasers Uses SLAC Linac 1. 5 - 15 Å (0. 5 -5 Å in 3 rd harmonic) Peak brightness 10 orders of magnitude above Advanced Photon Source (APS) Time averaged brightness 2 -4 orders of magnitude above APS Sub-picosecond pulses Fully transversely coherent radiation Design and R&D studies, a ANL-BNL-LANL-LLNL-SLACUCLA collaboration The X-ray FEL is a powerful tool to explore matter and fundamental physics. Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

The transition from 3 rd generation light sources to x-ray free-electron lasers LCLS Project Overview FELs Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview The SASE principle and linac-driven free-electron lasers • Main components of a SASE FEL – A bright electron source (photo-injector) – A bunch compression system – A linear accelerator – An undulator – The photon beamlines – The experimental areas Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview LCLS layout Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview SASE FELs SASE FEL theory well developed and verified by simulations and experiments • FEL radiation starts from noise in spontaneous radiation Saturation Exponential Gain Regime • Transverse radiation electric field modulates the energy and bunches the electrons within an optical wavelength Undulator Regime • Exponential build-up of radiation along undulator length 1 % of X-Ray Pulse 0. 9 fs 0. 2 fs Electron Bunch Micro-Bunching Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview Main parameters • Wavelength 1. 5 Å (range 1. 5 -15 Å, 1 st harm) • Saturation peak power 9 GW 14. 35 Ge. V • Peak brightness 1. 2 1033 230 fsec (full) • Average brightness 4. 2 1022 • Electron energy (range 14. 35 -4. 54) • Bunch length • 1012 coherent photons/pulse • Undulator length 120 m • Undulator gap 6 mm Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview Light source performance chart Average Peak and time averaged brightness of the LCLS and other facilities, operating or planned Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview Other FEL based light sources are being tested, built or planned • The TESLA Test Facility (TTF) at DESY – Lasing with gain ~3000 observed at 80 -180 nm • X-ray FEL TESLA at DESY (associated with the linear collider project) – CDR being written • Source Development Laboratory (SDL) at BNL-NSLS – Electron beam testing • Harmonic Generation (HGHG) experiment successful at BNL-ATF • VISA experiment at BNL-ATF – Study the FEL radiation with beam characteristics and tolerances close to those of the LCLS • FELs under study in Japan, Italy, England Germany (BESSY II) • LEUTL at ANL-APS – First observation of saturation Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview FEL experiment • A crucial milestone in FEL physics was reached when the LEUTL experiment measured large amplification and evidence of saturation last summer at 530 and 385 nm Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

Energy deviation along electron bunch Transverse cross section of electron beam 6 D particle tracking through LCLS accelerator Max Cornacchia, SLAC LCLS Project Overview 150 Me. V 250 Me. V 4. 54 Ge. V 14. 3 Ge. V BESAC, Feb. 26 -27, 2001

LCLS Project Overview How to achieve a short bunch • The simulation tool was used to optimize the electron beam in 6 -dimensional phase space –Preservation of transverse electron brightness leads to shorter undulator and more relaxed tolerances –Mechanism for achieving short electron bunches (230 fs) confirmed by the simulations –Even shorter bunches can compromise transverse electron brightness 230 fs bunch length is the result of optimization in all 6 dimensions Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview X-ray optics transport simulations Viewer GINGER output: Tables of electric field values at undulator exit at different times viewer 0 150 R, mm Transformation to Frequency Domain Power Density Time Domain Frequency Power Density. Domain watts x 1015 c m 2 1. 94 0 x 1017 Temporal 1. 73 Transform 0 w 0 -400/fs 2 4 0 6 Time, femtoseconds Power Density watts x 1015 c m 2 1. 94 x 1017 w 0+400/fs frequency watts c m 2 Propagation to arbitrary z Spatial 1. 73 Transform 0 -150 0 150 Transverse position, microns Max Cornacchia, SLAC watts c m 2 0 -325 -10 304 Wavenumber, mm-1 BESAC, Feb. 26 -27, 2001

LCLS Project Overview LCLS Undulator Hall and Experimental Area Layout FFTB hall for undulator and diagnostics Hall A: Atomic Physics Warm Dense Matter X-Ray Physics Max Cornacchia, SLAC Hall B: Nanoscale Dynamics Femtochemistry Biological Imaging BESAC, Feb. 26 -27, 2001

LCLS Project Overview Conceptual Design Report • Conceptual Design Report is on schedule • First draft contributions are being reviewed • Goal is to have it ready, in draft form, by early summer 2001 Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001

LCLS Project Overview Summary • Substantial progress made in most areas • Experimental confirmation of the photo-injector brightness is the most important short term goal – Program is receiving strong support from SLAC • Integration photo-injector/FEL physics/x-ray optics to continue – Realistic x-ray FEL characteristics, tolerances, match to the experiments • X-ray optics to address detailed requirements of the “first experiments” • Focus on CDR for the next 6 -8 months • Preparation for Lehman Review Max Cornacchia, SLAC BESAC, Feb. 26 -27, 2001