Bunch Compressor 3 Torsten Limberg for Frank Stulle et al.

Basic Bunch Compression Mechanism with Magnetic Chicane  s = -R56* 

TTF-II Compression System Two stage compression to avoid space charge emittance dilution on one hand and reduce non-linear effects from the RF system on the other. BC2BC3 BC2BC3

BC-3 Lay Out R56: mm

Incoming optics matching section

First half of S-bend

2 nd part of S-bend

Outgoing matching section

Horizontal Dispersion in BC-3

Optics of BC-3

Longitudinal Phase Space Evolution

TraFiC4 results: slice emittance and projected emittance development through BC-3 for different designs

Transverse emittance, peak current, mean energy of longitudinal slices and energy spread along the bunch at the undulator entrance (ca. 60% of the bunch =6nm ) (s > 0 corresponds to the bunch tail)

TTF-II Starting Scenario ( TTF-II Starting Scenario ( =30nm) BC2 BC3

Transverse emittance, current, energy spread along the bunch and longitudinal phase space at entry of BC-2 (E. Schneidmiller et al.)

Transverse emittance, current, energy spread along the bunch and longitudinal phase space at exit of BC-2

Transverse emittance, current, energy spread along the bunch and longitudinal phase space at exit of BC-3 (including CSR effects in 1-d model)

Transverse emittance, current, energy spread along the bunch and longitudinal phase space at entry of undulator (including space charge effects in upstream drift)

Peak current vs. transverse emittance for given slice energy spread and saturation at the end of the undulator ( =30nm, 30% safety)

Status of Instrumentation (D. Nölle) Strip lines (4): April 03 Strip lines (4): April 03 Pickup Array (2): feed throughs ready for assembly Pickup Array (2): feed throughs ready for assembly Toroids (2): March 03 Toroids (2): March 03 OTR Stations Standard (2): Feb 03 OTR Stations Standard (2): Feb 03 OTR 75 m: OTR System OK, chamber not ordered OTR 75 m: OTR System OK, chamber not 78 m:design done, window flanges, screen and optical system need to be 78 m:design done, window flanges, screen and optical system need to be procured Resistance Monitor: April 03 Resistance Monitor: April 03 Phase monitor: March 03 Phase monitor: March 03

Vacuum Chamber Support Status

Summary BC3 design complete and fabrication of components mostly on schedule BC3 design complete and fabrication of components mostly on schedule Two operating scenarios for the bunch compression system: Two operating scenarios for the bunch compression system: With 3rd harmonic RF With 3rd harmonic RF Full start to endsimulation done, lases at 6 nm Full start to endsimulation done, lases at 6 nm For start up: No 3rd harmonic RF, lower energy For start up: No 3rd harmonic RF, lower energy Start to end simulation begun, lases at 30 nm Start to end simulation begun, lases at 30 nm