1. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 0 mode studies in LCLS injector gun C.Limborg-Deprey Frequency analysis of 0-Pi mode Determination of amplitude of 0 mode voltage from Frequency domain method PARMELA simulations

2. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Ratio of 0mode amplitude to pi mode

3. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Ratio of 0mode amplitude to pi mode WRONG RESONANCE

4. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Ratio of 0mode amplitude to pi mode

5. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Low Power pulse -

6. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Ratio of 0mode amplitude to pi mode WRONG RESONANCE

7. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Ratio of 0mode amplitude to pi mode

8. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 PARMELA Simulations Emittance Variation vs Amplitude in the 0 mode For a 10MV/m amplitude in 0 mode, can there any beneficial effect of the 0 mode?

9. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 SuperFish Map for PARMELA simulations 0 mode

10. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 PARMELA Simulations with 0 and Pi modes Crude simulations With 5.5 k particles PARMELA Simulations even with 3 MV/m (magenta curve) in the 0 mode, there is some increase in emittance for half of the phases

11. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 PARMELA Simulations with 0 and Pi modes PARMELA Simulations with 20k particles Half of the phases degrade the emittance, the other half improve it at 2.852 GHz, a period is 0.5 degrees longer than at 2.856 GHz

12. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 PARMELA Simulations with 0 and Pi modes PARMELA Simulations with 20k Half of the phases degrade the emittance, the other half improve it at 2.852 GHz, a period is 0.5 degrees longer than at 2.856 GHz

13. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Looking for better tuning when 0-mode is at  = 150  Injection phase does not help Varying pi mode field amplitude helps BUT Nearly enough + Sensitivity to field variation is increased + Difficulty to find  0-mode = 150 

14. Cecile Limborg-Deprey 0 mode in LCLS injector gunlimborg@slac.stanford.edu August 28th 2004 Time domain model 3  s Klystron exciting the 0 mode Rs_0 = 4.94E+06 ; Q0_0 = 12578; Qext_0 = 10000; f_0 = 2.8526e9; 3  s Klystron exciting the PI mode Rs_0 = 4.71E+07 ; Q0_0 = 13957; Qext_0 = 6988; f_0 = 2.856e9;