1. UCLA/ATF chicane compression experiments
Coherent radiation
exit port
Extend UCLA chicane experiments to regime with significant acceleration-field
Chicane designed, fabricated and characterized at UCLA
Extensive simulation work
Coherent radiative effects central to mission
Add to ATF core capabilities…
SASE FEL
Wakefield studies

2. Implementation TV & Streak-camera ~100 us ~1-2 us 10 W 0.1 W t
Phosphor + OTR
Ti Foil
Magnetic Kicker
E-beam
Vacuum chamber

3. Bunch length diagnostic comparison
Device Type
Invasive
measurement
Single shot
Abs. or rel.
Timing
Detect
m bunching
RF Transverse
Deflecting
Cavity
Yes: Steal 3 pulses
No: 3 pulses
Absolute No
Coherent
Radiation
Spectral power
No for CSR
Yes for CTR
Yes
Relative
Autocorrelation
(2nd moment only)
Electro Optic
Sampling
Energy
Wake-loss

6. Transverse Emittance measurements
all for Q = 1 nC
F = Fm – 5°
Imain = 326 A
F = Fm
Ibuck = Imain * 0.075
VUV-FEL (30 nm)
VUV-FEL (6 nm)
min. emittance improved
geom. average improved
still a long way to go for XFEL requirements !
XFEL

7. Longitudinal Emittance Measurement
Technique analagous to quadrupole scan of transverse emittance
3 m linac
(vary flinac)
Quad
Doublet
Gun
Spectrometer
Energy Screen
Determine Longitudinal
f-Space at Linac Entrance
Measure Energy Spectra vs linac phase
Linear analysis allows only linear time energy correlations
Fit t11, t12, t22, Vlinac, and qlinac
Courtesy, J. Schmerge