LCLS Linac Update E. Bong Facility Advisory Committee Meeting October 12, 2004 LCLS October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac Update Brief Overview L 1 & BC 1 Progress LTU & E-Dump Status Continuing Resolution Impact October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Nominal LCLS Linac Parameters for 1. 5 -Å FEL Single bunch, 1 -n. C charge, 1. 2 -mm slice emittance, 120 -Hz repetition rate… 250 Me. V z 0. 19 mm 1. 6 % Linac-X 4. 54 Ge. V z 0. 022 mm L =0. 6 m 0. 71 % rf= -160 Linac-1 Linac-2 Linac-3 L 9 m L 330 m L 550 m rf -25° rf -41° rf -10° 135 Me. V z 0. 83 mm 0. 10 % L LS LC LC J J N IIN SLAC linac 21 -1 b 21 -1 d DL-1 L 12 m R 56 0 X BC-1 L 6 m R 56 -39 mm 21 -3 b 24 -6 d SLAC linac tunnel BC-2 L 22 m R 56 -25 mm 25 -1 a 30 -8 c 14. 1 Ge. V z 0. 022 mm 0. 01 % E-Dump undulator L =130 m LTU L =275 m R 56 0 research yard (RF phase: frf = 0 is at accelerating crest) October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Baseline System Design 1. 5 -Å SASE FEL Linac: Requirements Acceleration to 14. 3 Ge. V (4. 5 Ge. V min. ) Bunch compression to 3. 4 k. A (gex, y 1. 2 mm) Emittance preservation (<20% ‘slice’, <100% ‘projected’) Final energy spread (<0. 02% ‘slice’, <0. 1% ‘projected’) Minimal sensitivity to system ‘jitter’ Diagnostics integrated into design Flexible operations (1. 5 to 15 Å, low-charge, chirp, etc. ) Compatibility with other SLAC programs use 2 compressors, 3 linacs Linac Physics Requirement Document PRD# 1. 3 -001 October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS/SLAC Program Compatibility Program Changeover Time 15 minutes from LCLS to damped SLAC beam 24 hours from LCLS to undamped ESA beam Moving Chicanes Articulates collinear with linac axis for straight-ahead X-Band Structure Aperture 7 mm, smaller than linac scrapers (16. 5 mm) Smaller than undamped beam Moves off-axis, temporary pipe installed BPM Module Design Charge Range. LCLS 0. 2 n. C to 1 n. C. Full ESA beam October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
L 1 & BC 1 Subsystem Linac 1 (L 1) Treaty Point LCLS Injector/LCLS Linac LCLS Injector Two short accelerator structures, refurbished Quads+BPMs, X&YCOR Bunch Compressor 1 (BC 1) X-Band Structure (NLC) Quad + BPM, YCOR, XCOR, QE, Toroid Bunch Compressor & Diagnostics Emittance Diagnostics. LCLS Linac Remove 5 S-Band Structures Electrons System background 3 -D complete X-Band structure and waveguide network design in progress BC 1 chicane articulation design in progress Dimensional checks between mechanical layout and physics deck performed Work remaining: short accelerators, emittance diagnostics section October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
X-Band System Design 60 cm structure from Fermi Integrated into beamline layout Translation to be designed XL 4 Klystron NLC waveguide components designed for 8 -Pack October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
BC 1 System Design Status Articulated bunch compressor layout Dynamic solid modeling Bend Magnets LLP Install FY ’ 06 shutdown BC 1 inter-bend diagnostics package BPM, collimator, OTR October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac L 2, BC 2, L 3 Except for BC 2 in Linac Sector 24, Linac Sectors 22 -30 largely unmodified System schematics complete 3 -D models of area backgrounds near complete File management structure for 3 -D models complete October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac LTU Subsystem Schematic Energy and emittance diagnostics, energy collimation, bunch length diagnostics and undulator launch feedback 3 -D solid automated layout generated from MAD done October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Multiple Undulator Expansion Capability LTU Multiple beamlines NOT in LCLS baseline scope Baseline design not to exclude possibility of expansion October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Main Dump and Safety Dump Main dump electromagnets allow energy and energy spread measurements Safety dump permanent magnets deflect e-beam on BYD failure Ray traces show no beam transported through wall in any failure condition Working with SLAC Radiation Safety for approval of design October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac Work Plan by Area Design, Long Lead Procurement, Construction, Installation, FEL Commissioning LLP X-Band L 1, BC 1, L 2, BC 2 and L 3 must be installed during SLAC Linac downtimes. October 12, 2004 FAC LCLS Linac Update LLP BC 1 BC 2 Bends SLAC Linac Downtimes Eric Bong BONG@slac. stanford. edu
LCLS Linac Organizational Chart Resources obtained through both direct hire and matrixed from SLAC departments Resources within groups distributed based on project demands Communication between systems managed through Interface Control Documents October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac Challenges RF Stability Existing system phase and amplitude stable to requirements over several seconds Stability achievable over longer time scales using bunch length and energy feedback Bunch Length Measurement & Feedback Bunch length measurement in R&D at SPPS Feedback modeling and simulation by J. Wu Epics/SLAC Controls System Compatibility Require Epics system to access SLC control system in order to operate existing equipment required for LCLS SLC control system needs to access EPICS system to operate LCLS upgraded equipment required in high power beam operations Articulated Bunch Compressors Articulation required for R 56 tuning for full range of beam charge Move for Accelerator centerline for un-damped beam operation BPM Module Design Measurement of full range of beam charge required Two beam e+ e- beam operations place additional challenge on module design October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Work Plan Next 6 Months Matrix in Klystron Dept. engineering and design support for X-Band modulator and LLRF design Begin procurement of X-Band system Begin procurement of BC 1 & BC 2 dipoles Complete L 1 & BC 1 design & details Complete BC 1 diagnostics design & details Begin L 2 & L 3 system design Obtain Radiation Physics approval of safety dump design Continue jitter and feedback modeling Develop commissioning plans Develop detailed installation plan Integrate Injector and Linac engineering groups October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Linac System Progress Summary Linac baseline presented to EIR Linac area schematics complete Linac Li 21 -30 3 D backgrounds in process L 1, BC 1 and X-Band modeling underway Conducted L 1 & BC 1 preliminary design review E-Dump & Safety Dump design under radiation safety review Jitter model developed and feedback simulations conducted, presented at XFEL conference J. Wu October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
Continuing Resolution Impact Procurement of long lead items delayed Ramp-up of engineering effort delayed In most cases delays decrease schedule float X-Band Klystron will not be ready for FY’ 06 downtime October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
End October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
BC 1 X-Band Compressor October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac L 2 Subsystem Linac Sector 21 -3 b to 24 -6 d. Largely unmodified SLAC Linac. Energy chirps the bunch to allow compression in BC 2 RF stability critical Four wire scanners added for emittance measurement Requirements PRD# 1. 3 -004 October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac BC 2 Subsystem Linac Sector 24 -7 a to 24 -8 d, Remove eight S-Band structures compress a single 1 -n. C, 195 -mm long (rms) electron bunch, at a repetition rate of 120 Hz, at 4. 54 Ge. V to an rms length of 22 mm BC 2 Bends, Long Lead Procurement Item Requirements – PRD# 1. 3 -005 October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac L 3 Subsystem Linac Sector 25 to 30 largely unmodified. Two accelerator structures added, two structures moved, two wire scanners moved, transverse cavity moved, new OTR screen. Requirements PRD# 1. 3 -006 October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Linac LTU Subsystem New Beamline extending from FFTB muon plug wall in SLAC BSY, across research yard in new housing to FEL undulator Transports a 1 -n. C, 20 -mm long (rms) electron bunch, at a repetition rate of 120 Hz, at 14 Ge. V to the LCLS FEL undulator Includes energy and emittance diagnostics, energy collimation, bunch length diagnostics and undulator launch feedback Requirements PRD# 1. 3 -007 October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
LCLS Longitudinal Feedback Simulation feedback off feedback on (Integral gain: 0. 5) Juhao Wu (SLAC) October 12, 2004 FAC LCLS Linac Update Eric Bong BONG@slac. stanford. edu
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