LCLS Conceptual Design Report - Stanford Synchrotron Radiation ...

L C L S C O N C E P T U A L D E S I G N R E P O R T
5.6.3 Control of X-Ray Power Levels........................................................................... 5-26
5.7 The Temporal Structure of the X-Ray Pulse ................................................................... 5-27
5.8 LCLS FEL Commissioning ............................................................................................. 5-28
5.8.1 Procedural Aspects of the FEL Gain Commissioning.......................................... 5-28
5.9 Summary.......................................................................................................................... 5-29
5.10 References ....................................................................................................................... 5-29
6 Injector
Technical Synopsis ....................................................................................................................... 6-1
6.1 Introduction ....................................................................................................................... 6-2
6.1.1 Beam Requirements ............................................................................................... 6-2
6.1.2 Emittance Compensation........................................................................................ 6-4
6.1.3 Design Principles ................................................................................................... 6-5
6.2 Summary of Experimental Results .................................................................................... 6-8
6.2.1 Quantum Efficiency ............................................................................................... 6-9
6.2.2 Transverse Emittance Measurements................................................................... 6-10
6.2.2 Thermal Emittance ............................................................................................... 6-13
6.2.3 Longitudinal Emittance ........................................................................................ 6-14
6.3 RF Photocathode Gun...................................................................................................... 6-15
6.3.1 Gun Description ................................................................................................... 6-15
6.3.2 Field Strength and Cell Balance........................................................................... 6-17
6.3.3 Symmetrization .................................................................................................... 6-18
6.3.4 120 Hz Operation ................................................................................................. 6-19
6.3.5 Photocathode........................................................................................................ 6-19
6.3.6 Emittance Compensating Solenoid ...................................................................... 6-22
6.3.7 Vacuum System.................................................................................................... 6-23
6.4 Laser System.................................................................................................................... 6-24
6.4.1 System Description .............................................................................................. 6-25
6.4.2 Temporal Pulse Shaping....................................................................................... 6-30
6.4.3 Fourier Relay Optics ............................................................................................ 6-31
6.4.4 Spatial Pulse Shaping........................................................................................... 6-31
6.4.5 Frequency Conversion ......................................................................................... 6-31
6.4.6 Grazing Incidence ................................................................................................ 6-32
6.4.7 Stability of Laser Pulse ........................................................................................ 6-33
6.4.7.1 Pulse-to-Pulse Timing.......................................................................... 6-33
6.4.7.2 Pulse Duration ..................................................................................... 6-36
6.4.7.3 Optical Energy ..................................................................................... 6-36
6.4.7.4 Spot Size and Position ......................................................................... 6-37
6.4.8 Laser System Diagnostics .................................................................................... 6-37
T A B L E O F C O N T E N T S
6.4.8.1 Cross-correlation Pulse Shape ............................................................. 6-37
6.4.8.2 Energy.................................................................................................. 6-38
6.4.8.3 Spatial Shape ....................................................................................... 6-38
6.4.8.4 Stability of Spot Centroid .................................................................... 6-39