Transcript Introduction, Charge to the Committee

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
November 3, 2004
Injector RF Design Review
1
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
November 3, 2004
Injector RF Design Review
2
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
L0-1 & L0-2
3-m SLAC Sections
LO
A SS NG
EM B EL
BL LO
Y WS
SP
SE O OL
AL S
Load Lock
FR
OM
VA
OD
E
UH
G ATV A
E VALLME
LV TA
ES L
PO
H OL RC
DE U PIN
R E
CA
TH
LV
E
Laser Heater & Chicane
Gun Diagnostics
Transverse RF Cavity
Electro-Optic Diagnostic
OTR Emittance Diagnostics
Radiation Shield Walls
35o Bend
SLAC Main Linac Beamline
Straight Ahead Spectrometer
November 3, 2004
Injector RF Design Review
3
David H. Dowell
[email protected]
Sector 20
Sector 20 Alcove
Laser Bay
Drive Laser
Drive Laser
System
Transport
Tubes
Laser
Heater
Transport
Tube
RF Gun
Electron
Diagnostic
Laser Heater
November 3, 2004
Injector RF Design Review
UV Launch and
Condition.
Photocathode Gun &
Launch System
4
David H. Dowell
[email protected]
S20 Alcove Floor Plan
Laser Penetration
•Title I Completed
•Title II Specifications Released
•Room & Utilities Sized for 2 Drive Lasers
November 3, 2004
Injector RF Design Review
5
David H. Dowell
[email protected]
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
November 3, 2004
Injector RF Design Review
6
David H. Dowell
[email protected]
Gun to Linac Region
Cathode Load Lock
VA
CU
UM
PU
MP
S
TR
EA
TM
EN
T
CH
AM
BE
R
RF Gun
Gun Solenoid
LO
AS NG
SE BE
MB LL
LY OW
S
S
P
SE OO
AL LS
FR
OM
CA
TH
OD
E
UH
GA V A
TE LL
VA ME
LV TA
ES L
PO
HO RC
LD UP
ER INE
VA
LV
E
Porcupine
Cathode
Clamp
Linac Solenoid
L0-1
Gun Spectrometer
November 3, 2004
Injector RF Design Review
7
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
November 3, 2004
Injector RF Design Review
8
David H. Dowell
[email protected]
Measurements of Gun Solenoid Multipole Fields
Magnetic Field Strength (G)
Multipole Amplitude
3
Dipole 100
2.5
2
1.5
1
0.5
0
-0.2
Quadrupole 100
Sextupole 100
Gun Solenoid will have Dipole and Quadrupole
Correction Coils
Dipole 150
Quadrupole 150
Sextupole 150
Dipole 200
-0.1
0
0.1
0.2
Quadrupole 200
Sextupole 200
Longitudinal Position (m)
Magnetic Field Phase (?)
Multipole Phase
180
135
90
45
0
-45
-90
-135
-180
-0.2
Dipole 100
Quadrupole 100
Sextupole 100
Dipole 150
Quadrupole 150
•Solenoid being designed with both
dipole and quadrupole correcting coils
Sextupole 150
Dipole 200
-0.1
0
0.1
0.2
Quadruipole 200
Sextupole 200
Longitudinal Position (m)
November 3, 2004
Injector RF Design Review
9
David H. Dowell
[email protected]
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
November 3, 2004
Injector RF Design Review
10
David H. Dowell
[email protected]
LCLS Project Schedule
November 3, 2004
Injector RF Design Review
11
David H. Dowell
[email protected]
LCLS Injector and Linac Schedule
Gun and L0-1 needed for installation:
October 2006
November 3, 2004
Injector RF Design Review
12
David H. Dowell
[email protected]
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.
November 3, 2004
Injector RF Design Review
13
David H. Dowell
[email protected]