1. BC System – Review Options ● BC2 working point (energy-charge-compr.) ● 2BC (rf-rf-bc-rf-bc-rf) ● table: 2BC (rf-rf-bc-rf-bc-rf) dogleg + 2BC (rf-dog-rf-rf-bc-rf-bc-rf) n3BC (rf-bc-rf-rf-bc-rf-bc-rf) 3BC (rf-rf-bc-rf-rf-bc-rf-bc-rf) rollover compression ● laser heater ● cases in detail peak current projected emittance slice emittance uncorrelated energy spread remaining chirp µ-bunch stability parameter-sensitivity arrival time stability

2. energy charge compression 1nC 511 MeV 1 GeV 1.5 GeV 2 GeV 2.5 GeV 5 10 15 20 30 40 full -40 -20 0.5nC 0.25nC 0.125nC BC2 working point details; see: http://www.desy.de/~dohlus/2005/2005.01.xfel/xfel_jan2005.pdf

3. 2BC (rf-rf-bc-rf-bc-rf) rf knobs r56 knobs compression factors absolute tolerances (amplitude & phase_deg) µ-bunching gain chirp minimal relative tolerances shot noise due to µ-bunching gain

4. inverse tolerance noise: I rms /A const.: E1, E2, E2’’, E2’’’, r56 coll, C1, C1*C2 tuned: E1’, E2’, r56 BC2, parameter: r56 BC1,  L2 inverse tolerance noise I rms /A

5. const.: (E1), E2, E2’’, E2’’’, r56 coll, (C1), C1*C2 tuned: E1’, E2’, r56 BC2, parameter: r56 BC1,  L2 20,500 10,500 10,400 20,400 5,400 C1, E1/MeV inverse tolerance nois e I rms /A E1 = 400 MeV r56BC1 = 90mm, C1=5 r56BC2 = 75mm, C2=20  L2 = 10 deg min(ampl_tol) = 0.1% min(phas_tol) = 0.023 deg noise: I rms = 147 A min(phas_tol) = 0.016 deg noise: I rms = 260 A

6. 2BC rf (1+3) -bc-rf-bc-rf-c rollover compr. rf (1+3) -bc-rf-bc-rf-c dogleg+2BC rf-d- rf (1+3) -bc-rf-bc-rf-c n3BC rf-bc- rf (1+3) -bc-rf-bc-rf-c 3BC rf (1+3) -bc- rf (1+3) -bc-rf-bc-rf-c E=400MeV 2GeV 17.5GeV C=5 20 0.98 r56=-90mm -75mm 0.84mm ampl_tol=0.1% ph_tol=0.023deg noise= 147 A  L2 = 10 deg E=500MeV 2GeV 17.5GeV C=10 10 0.98 r56=-100mm -200mm 0.84mm ampl_tol=0.2% ph_tol=0.055deg small  L2 = 40.5 deg E=130MeV 400MeV 2GeV 17.5GeV C=1.2 4.17 20 0.98 r56=40mm -90mm -87.2mm 0.84mm ampl_tol=0.11% ph_tol=0.040deg noise= 270 A e’=1%@ 130MeV  L2 = 10 deg t566_dog=1m E=130MeV 500MeV 2GeV 17.5GeV C=1.45 6.90 10 0.98 r56=-30mm -90mm -45.0mm 0.84mm ampl_tol=0.09% ph_tol=0.048deg noise= 95 A e’=2.5%@ 130MeV  L2 = 10 deg E=130MeV 400MeV 2GeV 17.5GeV C=1.25 4 20 0.98 r56=30mm -80mm -83.7mm 0.84mm ampl_tol=0.11% ph_tol=0.045deg noise= 93 A e’=1.6%@ 130MeV  L2 = 10 deg t566_dog=1m

7. laser heater 1% energy offset  transv. rms beam size overlap of electron and laser beam !!!

8. cases in detail ● 2BC (rf-rf-bc-rf-bc-rf) ● dogleg + 2BC (rf-dog-rf-rf-bc-rf-bc-rf) ● n3BC (rf-bc-rf-rf-bc-rf-bc-rf) ● 3BC (rf-rf-bc-rf-rf-bc-rf-bc-rf) ● rollover compression

9. 2BC (rf-rf-bc-rf-bc-rf)

10. dogleg + 2BC (rf-dog-rf-rf-bc-rf-bc-rf)

11. n3BC (rf-bc-rf-rf-bc-rf-bc-rf)

12. 3BC (rf-rf-bc-rf-rf-bc-rf-bc-rf) const.: E0=130MeV, E0’’, E0’’’,(E1), E2, E2’’, E2’’’, r56 coll, C0=1.5,(C1), C1*C2 tuned: E1’, E2’, r56 BC2, parameter: r56 BC1,  L2 E1 = 400 MeV r56BC0 = 30mm, C0=1.45 r56BC1 = 90mm, C1=6.9 r56BC2 = 45mm, C2=10  L2 = 10 deg min(ampl_tol) = 0.088% min(phas_tol) = 0.048 deg noise: I rms = 97 A inverse tolerance nois e I rms /A 20,500,5 15,500,5 15,400,5 20,400,5 10,400,5 C1*C0, E1/MeV,r56 BC0 /cm 1.45*6.9,400,3

14. rollover compression 1nC 50 A 500 A5 kA7 MeV130 MeV500 MeV2 GeV17.5 GeV 4 modules12 modules100 modules 3 rd (heater) (500 MeV) (2 GeV) details; see: http://www.desy.de/xfel-beam/data/talks/talks/dohlus_-_rf_param_sensitivity_lcls_xfel_20060821.pdf min(phas_tol) = 0.055 deg