International Linear Collider at Stanford Linear Accelerator Center

International Linear Collider at Stanford Linear Accelerator Center Electron Source Configuration Axel Brachmann - SLAC Jan. 19 2006, KEK GDE meeting

International Linear Collider at Stanford Linear Accelerator Center Layout as defined in the Baseline Configuration Document E=70 -100 Me. V laser Positron-style roomtemperature accelerating section sub-harmonic bunchers + solenoids standard ILC SCRF modules diagnostics section Additional Responsibilities: Ø Injector Damping ring transfer Ø SPIN control (LINAC longitudonal DR vertical)

International Linear Collider at Stanford Linear Accelerator Center Overview Ø Laser System and (laser) optical transfer see Snowmass ’ 05 Ø Polarized Gun Ø Bunching Section Ø NC pre-accelerator Ø SC e- Injector LINAC Ø Basic component count Ø Length estimates References: - TESLA TDR - A. Curtoni, M. Jablonka; Study of the TESLA preaccelerator for the polarized beam, TESLA-2001 -20

International Linear Collider at Stanford Linear Accelerator Center 120 k. V DC Gun – Baseline Design is SLC Gun Ion Pump RGA Load-lock and cesiator on other side BPM High voltage insulator laser beam e- beam Load-lock chamber connects here Magnetic lens Approximate location of cathode Leak valve

International Linear Collider at Stanford Linear Accelerator Center Loadlock System for Cathode Preparation and Installation

International Linear Collider at Stanford Linear Accelerator Center ILC DC Gun Design Ø SLC gun is baseline • 120 k. V, 1. 7 MV/m at Cathode • Possible higher gradient, eg. at Cornell, Jefferson Lab, Nagoya • New electrode materials, cesiation schemes Ø Polarized RF gun R&D

International Linear Collider at Stanford Linear Accelerator Center Bunching Section Ø SHB • • • Normal conducting sub-harmonic bunching section Focusing by solenoidal field Scaling from TTF results in following parameters : Cavity # F [MHz] Voltage [k. V] Rs [M ] Q 0 P [W] 1 108 (1/12) 40 8. 8 3. 4*104 220 2 433 (1/3) 44 4. 4 1. 7*104 360 Distance between sub-harmonic buncher cavities: 200 cm Bunch compression: 97 o rms at entrance to second SHB cavity, and 30 o rms at buncher entrance Distance to buncher: 38 cm Ø Buncher • • • 2 cavities (5 cell) separated by λ/2 (115. 3 mm); =1 Structure 14. 8 MV/m (simulations with 12 MV/m) 12 Me. V beam energy after bunching

International Linear Collider at Stanford Linear Accelerator Center NC Pre-Accelerator • Energy from 12 Me. V ~ 70 - 100 Me. V • Positron style room temperature accelerating section • 17 cell cavities, one pair 31 Me. V energy gain using 10 MW klystron • Number of pairs must be selected – 2 pairs ~ 76 Me. V, 0. 28 mm. mrad (un. Emitt. ) – 3 pairs ~ 100 Me. V, 0. 2 mm. mrad (un. Emitt. ) • 1 triplet between pairs • 2 triplets to match to SC LINAC module • Spectrometer arm for independent tuning

International Linear Collider at Stanford Linear Accelerator Center 500 Me. V SC LINAC and 5 Ge. V e- Injector LINAC Ø STEP 1 • • Add ~ 424 Me. V Two standard SC LINAC modules of 12 cavities each Gradient: Eacc = 17. 8 MV/m Lower energy requires doublets instead of triplets Ø STEP 2 • Energy gain to 5 Ge. V by 18 standard cryomodules • Gradient: Eacc = 20 MV/m

International Linear Collider at Stanford Linear Accelerator Center Instrumentation Ø Special diagnostics: • Gun diagnostics • Vacuum • Dark current • QE diagnostics Integrated into gun design • Faraday cup • Mott polarimeter Ø BPM’s, Toroids, Wirescanners/Laserwires, Profile Monitors Ø Bunch length measurements (Marc Ross proposals): • Band pass mirco wave detectors • Beam phasing • Energy / time correclations Ø Common instrumentation requirements with e+

International Linear Collider at Stanford Linear Accelerator Center Layout and Length Estimates Component Distance [m] Pre-Gun Systems (Laser, OTR, Local Injector Controls) ~ 50 Guns and Load-Lock Installation ~5 Y extension lines (with diagnostics and solenoidal field) ~3 SHB 1 (solenoidal field) ~3 SHB 2 (solenoidal field) ~3 Buncher ~ 2. 5 Pre-accelerator (to 500 Me. V, 17. 8 MV/m) ~ 30 RT – SC beamline ~ 12 Injector Linac (to 5 Ge. V; 18 17 m SC modules 20 MV/m) ~ 306 e- injector to DR transfer line with SPIN rotator ~25 Total Length of Injector Area 439

International Linear Collider at Stanford Linear Accelerator Center Components (e- and e+ source) Components Count Laser systems 2 Guns 2 ‘Y’ bend magnet 1 Solenoidal focusing magnets Dipols 9 m Diagnostic arm 1 DR transfer 1 Doublets Injection LINAC 2 Triplets Between NC pre-accelerator sections 1 Between NC and SC 2 Total 3 Buncher 1 Pre-accelerator 1 Injection LINAC 6 Total 8 Pre-accelerator 2 Injection LINAC 17 Total 19 DR In/out 2 Klystrons (10 MW) Cryomodules SPIN Rotator