Xband FEL Injector Simulation Progress Avni AKSOY CLIC
X-band FEL: Injector Simulation Progress Avni AKSOY CLIC FEL Collaboration – Jan 9 2014
Layout ● ● ● → 200 Me. V injector (standard S bad linac) 0. 2 ->6 Ge. V main accelerator (X-band linac) Any undulator λU=2. 5 cm → λSASE FEL ~ 0. 1 nm Within last month i have foccused on injector
Injector Layout Laser 3 GHz Photo Cathode RF GUN 3 GHz Traveling wave structures Optimization parameters for gun Laser parameters ● Laser pulse length? ● Laser spot size? Gun parameters ● Gradient? ● Bunch charge? ● Solenoid fields and positions? Injector structure ● Gradient? ● Length of Structure? ● Position of structure? ● Phase of structure?
Gun structure design (preliminary) ● 1. 6 Cell SLAC gun has been chosen (@ MAX IV it can operate @100 Hz) Parameter Value Unit – Laser radius 0. 4 mm Laser Pulse length 9 ps Charge 250 p. C Gun gradient 110 MV/m Gun phase 50 degre Gun solenoid Field 0. 34 T Emittance @cathode 0. 4569 mm. mrad
Gun results
Injector Structure (preliminary) Parameter Value Unit Frequency 3 GHz Gradient 12 MV/m Total length (except coupler cells) 2. 1 m Cell number 60+2 # Number of structures 13
Injector Simulation
Injector Simulation
Conclusion & further work ● ● For optimum bunch compression at the final position the RF parameters of injector can be optimized. . The study is preparation for start to end 6 d simulation However instead of using the PSI distribution we can use this result for fast optimization (I didnt have time to run Andrea's script with this distribution. . ). The emittance is larger than required value. The emittance after the gun and structures will be minimized. ● Wakefiled has not be included. . ● What is the acceptable length of a S-band accelerator? ● Better to use solenoid instead of quadrupole in low energy section. . ● I am waiting for the dimensions of a structure and gun?
Swiss. FEL injector
Swis. FEL injector Swiss. FEL CDR 2010
- Slides: 11