INJECTOR (WBS 1.2.1) Jym Clendenin, SLAC April 23, 2002 SYSTEM DESCRIPTION TECHNICAL CHALLENGES HAZARDS COST ESTIMATE CONSTRUCTION AND CRITICAL PATH ISSUES LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

INJECTOR PERFORMANCE REQUIREMENTS LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

PHOTOINJECTOR SCHEMATIC 1.6-cell S-band rf gun (G) Cu cathode with load-lock Ti:sapphire laser Emittance compensation solenoid (S1) Booster (L0) - two SLAC 3-m sections Beam matched to L0 using S1 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

DIAGNOSTICS Electrooptic device for temporal pulse shape Wire scanners for transverse emittance RF kicker for longitudinal emittance Standard linac devices Toroids, Faraday cups BPMs Spectrometers etc. •Details of layout and diagnostics: Dave Dowell, Breakout 1/2 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

TI:SAPPHIRE LASER SYSTEM Ultra-stable oscillator 100 fs pulses, 79.33 MHz Temporal shaping: grating pair with computer controlled mask CPA using multi-pass bow-tie amplifier Spatially flattened, frequency tripled to 260-266 nm 500 mJ at cathode Oscillator Stabilizer Temporal Pulse Shaper Stretcher Amplifier Pump Spatial Flattener Vacuum Spatial Filter Compressor e- Gun Evacuated Transport Tube Harmonic Generator •Details of layout and diagnostics: Paul Bolton, Breakout 1/2 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

PARMELA Simulation Results 1 Transverse normalized rms emittance (top curve) and beam size vs distance from cathode 1 nC, 10 ps flat top laser pulse, 0.7 ps rise time, eth=0.3 mm.mrad assumed eprojected ~ 0.92 mm.mrad at end of booster LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

PARMELA Simulation Results 2 Slice emittance at booster exit “Slice” minor fraction of total longitudinal dimension eslice (mm.mrad) for 100 slices Axial distance from center of bunch (ps) •Details of simulations: Cecile Limborg, Breakout 1/2 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

EXPERIMENTAL RESULTS Published emittance values ~2 mm for 1 nC bunches PARMELA predicts factor 2 improvement with uniform temporal Gun Test Facility (GTF) at SLAC dedicated to LCLS injector studies Emittance measurements consistent with PARMELA 1-2 mm for 100 A, 150-250 pC bunches More operating parameters to be optimized Plan slice emittance measurements in coming year •Discussion of experiments: John Schmerge, Breakout 1/2 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

TECHNICAL CHALLENGES Laser system temporal uniformity Computer controlled feedback on electron bunch shape Laser system stability Goal is  0.5 ps Non-destructive single-pulse monitoring of electron temporal bunch shape Electrooptic device To stabilize booster rf as well as flatten electron bunch Load lock for cathode Reliable rf seal required LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

HAZARDS Ionizing radiation Class IV laser Other PPS design philosophy: Access to injector vault allowed when linac in operation state No injector operation allowed when linac in access state Radiation design: New 4-ft concrete radiation wall between inj. vault and acc. housing Pb bricks various locations along linac opposite inj. vault Insertable Pb shield in injector line. Class IV laser Other HV, cryogens, heavy objects, dust, etc. LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

1.2.1 Injector Cost Estimate (FY02 Dollars, Thousands) Name PED Construction Contingency Total % contingency 1.2.1 Injector $ 4,926 $ 10,987 $ 4,498 $ 20,411 28% 1.2.1.1 $ 1,579 $ 6,505 32% 1.2.1.2 Mechanical $ 677 $ 185 $ 862 27% 1.2.1.3 Vacuum $ 876 $ 307 $ 1,183 35% 1.2.1.4 Diagnostics $ 1,323 $ 373 $ 1,696 1.2.1.5 Power Conversion $ 817 $ 204 $ 1,022 25% 1.2.1.6 Magnets $ 544 $ 159 $ 703 29% 1.2.1.7 Controls $ 1,405 $ 441 $ 1,846 31% 1.2.1.8 PPS $ 237 $ 59 $ 295 1.2.1.9 RF $ 2,100 $ 578 $ 2,678 1.2.1.10 Laser $ 3,008 $ 613 $ 3,620 20% LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

CRITICAL PATH ISSUES Goal: Commission injector spring 2006 Laser system prototyping must begin in FY04 to make spring 2006 goal Rf gun construction and pre-beam testing of will take 1 year E-O device State-of-the-art requiring significant prototyping 1 year to develop working model LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

PED MILESTONES FY03 December 2002 March 2003 June 2003 September 2003 Gun laser specifications and preliminary design Preliminary beamline layout March 2003 RF gun specifications and preliminary design Laser oscillator bid package June 2003 Load lock specifications and preliminary design September 2003 E-O diagnostic specifications and preliminary design Design of timing/rf distribution Specifications and preliminary design of controls software Power supply specifications LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

PED MILESTONES FY04 December 2003 Beamline detailed layout Load lock engineering design March 2004 RF gun engineering design Laser pump bid package June 2004 Detailed layout all controls hardware September 2004 E-O diagnostic engineering design Laser uv conversion and transport to cathode design Design low level rf system Engineering design of all components to be manufactured COMPLETED and all bid packages prepared by end September 2004 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

DELIVERABLES FOR CD-2 (Design Status) Existing components (design complete) Accelerator sections including rf deflector Some magnets, many power supplies Klystrons, modulators Components for which similar designs exist (existing designs modified) Gun solenoid All diagnostics except E-O device Remaining magnets, power supplies New components Gun laser system (specifications and preliminary design complete) 120-Hz rf gun (specifications and preliminary design complete) E-O device LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

CONSTRUCTION SCHEDULE FY05 October 2004 Send out bid packages, order parts Begin fabrication of gun, load-lock, magnets, supports June 2005 Laser room with components installed Begin installation beam line components Begin installation racks and components, cable trays, power supplies, system wiring LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

CONSTRUCTION SCHEDULE FY06 October 2005 Pump down vacuum system Checkout basic laser system Begin checkout beamline components, power supplies, diagnostics Install new protection systems February 2006 Begin commissioning injector First rf, first photoelectrons Accelerate beam through injector LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC

SUMMARY Using PARMELA, S-band rf photoinjector beamline designed to provide low-emittance beam meeting LCLS requirements A reliable, easily-replaceable, uniform emission photocathode system included Laser system design provides necessary energy, uniformity, stability Appropriate diagnostics identified PED milestones for FY03 and 04 presented Construction plan for FY05 and 06 presented to enable injector commissioning to begin by February 2006 LCLS DOE Review, April 23, 2002 Jym Clendenin, SLAC