1. Status of the Simulations on Photo Injector Optimization for Low Charges Yauhen Kot BD Meeting, 01.02.2010

2. Preliminary results work is not accomplished yet…

3. Optimization Code for the Photo Injector by M. Krasilnikov

4. BoosterACC13,9GHz Gun FLASH Photo Injector Booster phase is fixed Same gradient at booster and ACC1

5. + Bucking coil peak field E z1 (z=0)=45MV/m Optimization Code for FLASH Photo Injector

6. efld.dat FLASHgun_p12.dat Tuning parameters for efld Beam sizeXYrms0.170105 SolenoidMaxB(1)0.172724 Bucking Coil MaxB(2)0.019489 GunMaxE(1)45.00 Phi(1)-1.34264 BoosterMaxE(2)40.12 Phi(2)-14.85 Tuning parameters for FLASHgun_p12 Beam sizeXYrms0.15929 SolenoidMaxB(1)0.171247 Bucking Coil MaxB(2)0.015844 GunMaxE(1)45.00 Phi(1)-1.27222 BoosterMaxE(2)40.12 Phi(2)-14.85 horvert  0.32780.3273  reduced 0.29880.2982  37.5238.48  -2.204-1.792 horvert  0.31310.3128  reduced 0.2949  44.9745.87  -2.873-2.350 Field Files for the Gun Slightly different files but big consequencies

7. efld FLASHgun_p12 xx 37.52 yy 38.48 xx -2.204 yy -1.792 xx 20.61 yy 21.56 xx -0.509 yy -0.273  0.6356  reduced 0.4374  0.3266  reduced 0.2988 Calculated with best parameters for efld.dat. Comparison

8. Tuning Parameters ChargeXYrmsGun Phase, Phi(1) 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.0200.1050.0700.071-0.945-0.231-0.289 0.0400.1110.1010.103-0.491-0.565-0.523 0.1000.1830.17410.170-1.435-1.519-1.348 ChargeBooster gradient, MaxE(2)Booster phase, Phi(2) 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.02034.63839.8339.600.8870.3391.422 0.04022.27139.8336.880.867-0.7180.115 0.10034.58334.4039.600.1800.362-0.078 ChargeSolenoid MaxB(1)Bucking Coil, MaxB(2) 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.0200.17020.17230.17200.06720.00690.0157 0.0400.17290.17200.17240.02020.02310.0148 0.1000.1740 0.1741-0.0381-0.034-0.0221 Field File efld.dat - Booster gradient and phase were considered as parameters to be optimized - Best value for booster gradient was found in the near of the desired 40.12MeV almost in all cases - Booster Phase seems not to affect the emittance significantly - Results after ~50 Iterations with Optimization Code with 2000 particles

9. Results after Booster at s=9.0m ChargeEmittanceBunch length 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.0200.1800.1330.1260.6421.1121.254 0.0400.2540.1940.1890.9381.2221.342 0.1000.5330.3580.3171.0871.3361.478 ChargeBetaAlpha 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.0209.8731.2222.93-1.435-4.393-3.292 0.04088.7619.9515.46-10.80-3.073-2.332 0.10017.5711.579.13-3.234-2.182-1.630 ChargeEnergy rmsmomentum 1.1ps3.3ps4.4ps1.1ps3.3ps4.4ps 0.02044.8566.41115.679.9291.1990.65 0.04060.6556.8878.2452.9791.2184.76 0.10088.0898.39100.879.7779.3590.65 Field File efld.dat - Run with 200000 particles with the best values from the optimization code

10. Bunch Shape for 4.4ps and 3.3ps 20pC, pulse length = 4,4ps 100pC, pulse length = 4,4ps 40pC, pulse length = 4,4 ps 40pC, pulse length = 3,3 ps100pC, pulse length = 3,3ps 20pC, pulse length = 3,3ps Optimization procedure was cut after 40-50 iterations  possibly not enough to find really best values

11. Slice Energy Emittance and Slice Energy Spread for 4.4ps and 3.3ps

12. Convergency: Slice Energy Spread and Slice Emittance Q=100pC Pulse Shape: Gaussian  =4.4ps N, x10 3 Mesh  m  mm  rms,mm E rms, keV  m  20015x250.3410.1321.47858.439.13-1.63 39221x350.3260.1291.48259.129.05-1.66 80030x500.3240.1291.48259.369.11-1.66 150041x680.3230.1291.48159.289.20-1.71 Main parameters after booster at s=9.00m

13. Sensitivity Test: Solenoid 100pC, 4.4ps I soll MaxB(1)  294.70.168220.445651.1691.3-40.86 296.50.169220.393933.6419.7-24.83 298.70.170470.328911.5148.3-9.294 299.60.170970.29891.3668.81-4.495 300.00.171220.29490.0044.97-2.873 300.40.171470.30473.3232.67-1.867 300.90.171720.324910.228.65-1.348 301.70.172220.387331.327.04-0.8815 303.50.173220.551887.112.25-0.4150 304.30.173720.752415511.31-1.099 Assume I soll (optimum)=300.0A - The accuracy of 0.1A of the set point of the solenoid current Should be sufficient to control the emittance - But big difference in the optics functions…

14. I soll MaxB(2)    5.60.005840.33997.90100.3-6.486 10.50.010840.32382.7975.99-5.010 16.00.016580.31500.0053.71-3.583 17.60.018340.31560.1348.21-3.211 20.10.020840.31991.5641.59-2.745 24.90.025840.34192.1932.25-2.025 29.80.030840.381821.227.12-1.557 34.60.035840.437038.724.51-1.269 Assume I soll (optimum)=16.0A Sensitivity Test: Bucking Coil 100pC, 4.4ps

15. Solenoid Test: Bunch Shape Still to clear up: if the emittance increase at higher solenoid field occurs only due to the tails of the bunch…

16. Bucking Coil Test: Bunch Shape

17. Summary Many open questions yet…