1. LCLS Injector: Introduction D. H
LCLS Injector: Introduction D. H. Dowell, SLAC Injector RF Review: November 3, 2004
Injector Performance Requirements
Injector Description
The LCLS Injector Facility at Sector 20
Detail of Gun to Linac Region
Gun and Solenoid Description
Injector RF Design Status & Schedule
Charge to this Committee

2. LCLS Injector Performance Requirements:

3. LCLS Injector Configuration
SLAC Main Linac Beamline
Transverse RF Cavity
Laser Heater & Chicane
35o Bend
Straight Ahead Spectrometer
L0-1 & L0-2
3-m SLAC Sections
Electro-Optic Diagnostic
OTR Emittance Diagnostics
Radiation Shield Walls
RF Gun & Solenoid
Load Lock
Gun Diagnostics

4. UV Launch and Condition.
Sector 20
Sector 20 Alcove
Laser Bay
Drive Laser
Drive Laser System
Transport Tubes
Transport Tube
Laser Heater
RF Gun
Laser Heater
UV Launch and Condition.
Photocathode Gun & Launch System
Electron
Diagnostic

5. S20 Alcove Floor Plan Title I Completed
Laser Penetration
Title I Completed
Title II Specifications Released
Room & Utilities Sized for 2 Drive Lasers

6. High Power RF for LCLS Injector
Walls of re-built S20 Alcove
No procurement of high power RF, except waveguide
Waveguide runs established and in design
LLRF System in design

7. Gun to Linac Region Cathode Load Lock RF Gun Gun Solenoid
Gun Spectrometer
Linac Solenoid
L0-1
Porcupine Cathode Clamp

8. Dual Feed RF Gun and Solenoid
Dual Feed/Racetrack Design Corrects RF Fields to Second Order
Solenoid Design Includes Both Dipole and Quadrupole Field Correctors

9. Gun Solenoid will have Dipole and Quadrupole Correction Coils
Measurements of Gun Solenoid Multipole Fields
Gun Solenoid will have Dipole and Quadrupole Correction Coils
Solenoid being designed with both
dipole and quadrupole correcting coils

10. Injector RF Design Status
L0-1 Accelerator section
Dual feed RF design complete
Engineering design nearly complete
Subject of this review
120 Hz Gun
Solenoid design complete, Drawings released
RF design nearly complete
Redesigned coupler holes solved pulsed heating problem
Adopted racetrack geometry for full cell
Issued RFI and held technical meetings with prospective vendors
Unresolved issues & Topics of this review:
Decide on 0-pi mode separation
Final design for bulk cooling system
Load lock deferred, SBIR proposal for funding

11. LCLS Project Schedule

12. LCLS Injector and Linac Schedule
Gun and L0-1 needed for installation:
October 2006

13. Charge to the Committee
Critically assess the RF, thermal and mechanical designs for the gun and first accelerator section (L0-1) which are proposed to meet the LCLS injector requirements
The Committee is asked to provide comments and recommendations on:
Beam dynamics and the dual feed and racetrack designs for the gun and L0-1 accelerator section.
The elimination of dipole and quadrupole field distortions with dual feed couplers and racetrack shaped coupler cells.
Thermal management and RF mode issues for the gun.
Thermal distortion of the gun when operated at 120 Hz & 120 MV/m.
Excitation of the 0-mode and its effect in the gun during the RF transient.
Whether or not the 0-pi mode separation should be increased.
Manufacturing, RF testing and tuning procedures.
The Committee is requested to respond to the following general issues:
1. Identify and quantify technical issues related to the Injector RF design
2. Determine if the design will meet LCLS requirements
3. Identify any technical issues not already included in design
4. Determine if design, RF tuning and construction plans are reasonable
5. Make comments and suggestions for improving the RF design
A written report of the committee’s comments and recommendations is requested.