Transcript LCLS Injector Overview D. H. Dowell, SLAC FAC Review April

LCLS Injector Update
D. H. Dowell, SLAC
FAC Review, October 12-13, 2004
Injector Performance Requirements
Conventional Facilities Update
Shield Wall Installed
Sector 20 Alcove
Title I complete
Title II begun
RF Design Update
Drive Laser Update
Injector Physics Update
Summary
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
LCLS Injector Performance Requirements:
Parameter
Value
Peak current
Charge
Normalized transverse emittance
projected/slice
Rate
Energy
Energy spread @ 135 MeV
projected/slice
Gun laser timing stability
Booster mean rf phase stability
Charge stability
Bunch length stability
100 A
0.1 – 1 nC
 1.2 / 1.0 m rms
October 12-13, 2004
Injector Update
120 Hz
135 MeV
 0.1 / 0.01 % rms
 0.50 ps rms
0.1  rms
 2.0 % rms
 5 % rms
David H. Dowell
[email protected]
LCLS Injector Configuration
RF Gun &
Solenoid
VA
TR
EA
TM
CU
UM
EN
MP
S
HA
MB
ER
PU
TC
LO
A SS NG
EM B EL
BL LO
Y WS
SP
SE O OL
AL S
Load Lock
FR
O
M VA
H
LV
E
CA
TH
OD
E
UH
G ATV A
E LL
VA ME
LV TA
ES L
PO
RC
OL U
DE PIN
R E
Gun Diagnostics
L0-1 & L0-2
3-m SLAC Sections
Laser Heater & Chicane
Transverse RF Cavity
Electro-Optic Diagnostic
Radiation Shield Walls
OTR Emittance Diagnostics
35o Bend
SLAC Main Linac Beamline
Straight Ahead Spectrometer
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
S20 Floor Plan
Overhead
Crane
Roll Up Equipment Door
Injector Vault Controlled
Entry Area
120.000
1'-0"
23
24
25
26
28
29
30
31
32
19'-10"
20'-0"
Load Lock
Room
12'-8"
27
Loading &
Work Area
11'-6"
4'x6'
36'-9"
1'-0"
22'-11"
6'x15'
6'x15'
8'-0"
60.000
11'-2"
10'-0"
typ.
60'-1"
19'-10"
Laser Bay
Controlled Entry
Area
INCHES
60
40
100
•Cable Plant Specs Defined
•Title II Design Started
0
1
Meters
2
P20-14
See PRD: Conventional Facilities
Specifications For the Sector 20 Alcove
Injector Update
P20-16
P20-15
P20-17
3'-6•"
KLYSTRON
3
Power Supply and
Control Racks
October 12-13, 2004
20'-0"
6' 8"
80
CONTROLS RACK
LKG-01
LKG-03
LKG-05
(EXISTING)
LKG-02
LKG-04
LKG-06
FRONT
FRONT
LKG-10 LKG-08
LKG-16
LKG-12
LKG-14
LKG-11
LKG-13
LKG-15
LKG-09 LKG-07
5'-11"
20
Large Equipment Access,
Removable Panel, 8 ft wide,
floor to ceiling
2'-4"
0
Laser Bay
14'-0"
10'-0"
Storage & Local
Control Area
I&C CONTROL RACKS
(NEW )
LKG-17
LKG-19
LKG-18
LKG=20
LKG-21
LKG-23
LKG-22 LKG-24
FRONT
RF CONTROL RACKS
(NEW)
RF Hut
MODULATOR
STA 20-8
(EXISTING)
David H. Dowell
[email protected]
RF Design Progress
L0-1 Accelerator section
Dual feed RF design complete
L0-1 engineering design nearly complete
120 Hz Gun
Solenoid design complete
RF design nearly complete
Redesigned coupler holes solved pulsed heating problem
Adopted racetrack geometry for full cell
Held technical meetings with prospective vendors
Unresolved issues:
Final design for bulk cooling system
Load lock deferred
Decide how much SLAC vs. vendor engineering and fabrication
Technical review first week of November
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
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
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
Localized Pulsed Heating of RF Coupling Port
Gun body stress
in Pa
•The BNL/SLAC/UCLA gun design
has a DT of 137oC/pulse at the port.
•The redesigned port gives a DT of
41oC/pulse.
•NLC designs limit DT to 50oC/pulse
Pulse Heating Analysis:
Zenghai Li and Liling Xiao
October 12-13, 2004
Injector Update
•Localized heating of the RF coupling
port.
•The heat flux (watts/m2) is shown for
the gun operating at 140 MV/m and
120 Hz.
•Total dissipated power is 3676 watts.
ANSYS Analysis:
John Hodgson and Nancy Yu
David H. Dowell
[email protected]
L0-1 Structure RF Design
October 12-13, 2004
Injector Update
D()/m
Head-tail angle
D (rad/m)
SLAC Single feed
0.78
0.078
Symmetric dual
0.63
0.063
Race-track dual
0.04
0.004
Cross Dual
0.20
0.020
David H. Dowell
[email protected]
L0-1 Structure RF Dual Feed
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
Drive Laser Update
(Details in “Drive Laser Update” Presentation)
Technical Review Committee Assembled
C. Barty (LLNL) chairman, M. Babzien (BNL), R. Falcone
(Berkeley), Y. Li (ANL)
Review Held July 21, 2004 at SLAC
Committee involved in procurement process
Laser baseline design is diode-pumped Ti:Sapphire based
upon extensive discussions with vendors
Request for Proposal ready to submit to vendors
Laser pulse shaping studies underway at BNL/DUVFEL
Developing collaboration with LLNL on both near term and
long term laser needs
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
Injector Physics,
see breakout
8% modulation
Diagnostics and Commissioning
Gun measurements
Accurate thermal evaluation
Gun spectrometer
6D beam characterization at 135 MeV
Simulations
Low Charge tunings
Name
80
r
D (80  5%)
Nom.,1nC,10ps
1.2 mm
0.9 rad
2.5
1 nC, 17.5 ps
0.85
0.75
1.5
0.2nC,10ps
0.39
0.38
2.5
0.2nC,5ps
0.42
0.37
5
RF studies
L01 dual feed, racetrack shape necessary
RF gun dual feed, racetrack shape in full cell
mode 0 studies
8MHz mode separation better
klystron pulse shaped
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
Injector Schedule
•Schedule Coordinated with Shutdowns
•Over a Year for Injector Commissioning
•Injector Not on Project Critical Path
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]
Summary and Conclusions
Conventional facilities at S20 defined to support Title II
Facilities for two drive lasers
RF design of 120 Hz gun nearly complete
Solenoid design with dipole and quadrupole correctors finished
Pulsed heating solved
Dual RF feed + racetrack full cell
L0-1 accelerator section
RF design finished
Engineering design in progress
RF design review first week of November
Beamline components (magnets) being designed
Drive laser specifications defined in Request for Proposal
October 12-13, 2004
Injector Update
David H. Dowell
[email protected]