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

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

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

4. 120 kV DC Gun – Baseline Design is SLC Gun
International Linear Collider
at Stanford Linear Accelerator Center
120 kV 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

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

6. SLC gun is baseline Polarized RF gun R&D ILC DC Gun Design
International Linear Collider
at Stanford Linear Accelerator Center
ILC DC Gun Design
SLC gun is baseline
120 kV, 1.7 MV/m at Cathode
Possible higher gradient, eg. at Cornell, Jefferson Lab, Nagoya
New electrode materials, cesiation schemes
Polarized RF gun R&D

7. Bunching Section SHB Buncher
International Linear Collider
at Stanford Linear Accelerator Center
Bunching Section
SHB
Normal conducting sub-harmonic bunching section
Focusing by solenoidal field
Scaling from TTF results in following parameters :
Distance between sub-harmonic buncher cavities: 200 cm
Bunch compression: 97o rms at entrance to second SHB cavity, and 30o rms at buncher entrance
Distance to buncher: 38 cm
Buncher
2 cavities (5 cell) separated by λ/2 (115.3 mm); =1 Structure
14.8 MV/m (simulations with 12 MV/m)
12 MeV beam energy after bunching
Cavity #
F [MHz]
Voltage [kV]
Rs [M] Q0
P [W] 1
108 (1/12) 40
8.8
3.4*104
220 2
433 (1/3) 44
4.4
1.7*104
360

8. Positron style room temperature accelerating section
International Linear Collider
at Stanford Linear Accelerator Center
NC Pre-Accelerator
Energy from 12 MeV  ~ MeV
Positron style room temperature accelerating section
17 cell cavities, one pair  31 MeV energy gain using 10 MW klystron
Number of pairs must be selected
2 pairs  ~ 76 MeV, 0.28 mm.mrad (un. Emitt.)
3 pairs  ~ 100 MeV, 0.2 mm.mrad (un. Emitt.)
1 triplet between pairs
2 triplets to match to SC LINAC module
Spectrometer arm for independent tuning

9. 500 MeV SC LINAC and 5 GeV e- Injector LINAC
International Linear Collider
at Stanford Linear Accelerator Center
500 MeV SC LINAC and 5 GeV e- Injector LINAC
STEP 1
Add ~ 424 MeV
Two standard SC LINAC modules of 12 cavities each
Gradient: Eacc = 17.8 MV/m
Lower energy requires doublets instead of triplets
STEP 2
Energy gain to 5 GeV by 18 standard cryomodules
Gradient: Eacc = 20 MV/m

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

11. Layout and Length Estimates
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)
SHB 2 (solenoidal field)
Buncher
~ 2.5
Pre-accelerator (to 500 MeV, 17.8 MV/m)
~ 30
RT – SC beamline
~ 12
Injector Linac (to 5 GeV; m SC modules 20 MV/m)
~ 306
e- injector to DR transfer line with SPIN rotator
~25
Total Length of Injector Area
439

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

13. Post - meeting comments and conclusions
International Linear Collider
at Stanford Linear Accelerator Center
Post - meeting comments and conclusions
Additional klystrons for redundancy
Re-evaluate acc. gradients
Re-evaluate SHB frequency
Update cryomodule lengths
Include chicane for energy collimation
Update length estimate