BC System – ReviewOptions

● 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

uncorrelatedenergy spread

remaining chirp

µ-bunch stability

parameter-sensitivity

arrival time stability

energy

charge

compression

1nC

511 MeV1 GeV

1.5 GeV2 GeV

2.5 GeV

510

1520

3040

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

2BC (rf-rf-bc-rf-bc-rf)

rf knobsr56 knobscompression

factors

absolute tolerances(amplitude & phase_deg)

µ-bunching gain

chirp

minimal relative tolerances

0

2

rmsnoise,

dGeI

I

shot noise dueto µ-bunching gain

mmBC156r

deg

L2

inverse tolerance noise: Irms/A

const.: E1, E2, E2’’, E2’’’, r56coll, C1, C1*C2tuned: E1’, E2’, r56BC2, parameter: r56BC1, L2

inverse tolerance

noiseIrms/A

const.: (E1), E2, E2’’, E2’’’, r56coll, (C1), C1*C2tuned: E1’, E2’, r56BC2, parameter: r56BC1, L2

20,500

10,500

10,400

20,400

5,400

C1, E1/MeV

inverse tolerance

noise

Irms/A

E1 = 400 MeVr56BC1 = 90mm, C1=5r56BC2 = 75mm, C2=20L2 = 10 degmin(ampl_tol) = 0.1%min(phas_tol) = 0.023 degnoise: Irms = 147 A

min(phas_tol) = 0.016 degnoise: Irms = 260 A

2BC

rf(1+3)-bc-rf-bc-rf-c

rollover compr.

rf(1+3)-bc-rf-bc-rf-c

dogleg+2BCrf-d-

rf(1+3)-bc-rf-bc-rf-c

n3BCrf-bc-

rf(1+3)-bc-rf-bc-rf-c

3BCrf(1+3)-bc-

rf(1+3)-bc-rf-bc-rf-c

E=400MeV2GeV

17.5GeV

C=520

0.98

r56=-90mm-75mm

0.84mm

ampl_tol=0.1%ph_tol=0.023deg

noise= 147 A

L2 = 10 deg

E=500MeV2GeV

17.5GeV

C=1010

0.98

r56=-100mm-200mm0.84mm

ampl_tol=0.2%ph_tol=0.055deg

small

L2 = 40.5 deg

E=130MeV400MeV

2GeV17.5GeV

C=1.24.17

200.98

r56=40mm-90mm

-87.2mm0.84mm

ampl_tol=0.11%ph_tol=0.040deg

noise= 270 A

e’=1%@ 130MeVL2 = 10 deg

t566_dog=1m

E=130MeV500MeV

2GeV17.5GeV

C=1.456.90

100.98

r56=-30mm-90mm

-45.0mm0.84mm

ampl_tol=0.09%ph_tol=0.048deg

noise= 95 A

e’=2.5%@ 130MeVL2 = 10 deg

E=130MeV400MeV

2GeV17.5GeV

C=1.254

200.98

r56=30mm-80mm

-83.7mm0.84mm

ampl_tol=0.11%ph_tol=0.045deg

noise= 93 A

e’=1.6%@ 130MeVL2 = 10 deg

t566_dog=1m

laser heater

1% energy offset transv. rms beam size

overlap of electron and laser beam !!!

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

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)

const.: E0=130MeV, E0’’, E0’’’,(E1), E2, E2’’, E2’’’, r56coll, C0=1.5,(C1), C1*C2tuned: E1’, E2’, r56BC2, parameter: r56BC1, L2

E1 = 400 MeVr56BC0 = 30mm, C0=1.45r56BC1 = 90mm, C1=6.9r56BC2 = 45mm, C2=10L2 = 10 degmin(ampl_tol) = 0.088%min(phas_tol) = 0.048 degnoise: Irms = 97 A

inverse tolerance

noise

Irms/A 20,500,5

15,500,5

15,400,5

20,400,5

10,400,5

C1*C0, E1/MeV,r56BC0/cm

1.45*6.9,400,3

rollover compression

1nC50 A

500 A 5 kA7 MeV 130 MeV 500 MeV 2 GeV 17.5 GeV

4 modules 12 modules 100 modules

3rd

keV 101 E 101 C keV 1002 E full2 C μm 1022

56 Er (heater)

m 2.0

256

r

m 1.0

156

r

m

91

e

m

90e

256

2 r

1

m

5.22

Lee

(500 MeV)

(2 GeV)

L22 tanGeV 2

GeV 5.1

m

5.17 keL

deg 5.40L2 GV 973.1L2 Udetails; see:

http://www.desy.de/xfel-beam/data/talks/talks/dohlus_-_rf_param_sensitivity_lcls_xfel_20060821.pdf

min(phas_tol) = 0.055 deg