Transcript First Commissioning Experience

Initial Experience with Injector
Commissioning
P. Emma, et al.
Facilities Advisory Committee Meeting
April 16, 2007
LCLS
http://www-ssrl.slac.stanford.edu/lcls/internals/commissioning/index.html
April 16, 2006
LCLS FAC
1
Paul Emma
[email protected]
LCLS Injector Through BC1
RF Gun & Solenoid + YAG screens
6 MeV
L0a&L0b S-Band Linacs
Transverse RF Cavity
Bunch-Compressor-1
(BPM, OTR, collimator)
OTR & Wire Scanners
Gun
Spectrometer
Wire
Scanners
+ OTR
L1 S-Band Linac
135 MeV
250 MeV
X-Band RF
Straight Ahead Spectrometer
Bunch Length Diagnostics
~45 m (150 ft)
April 16, 2006
LCLS FAC
2
TD11
stopper
Paul Emma
[email protected]
Electron Beam Transported
to All Injector Areas
April 5: First photo-electrons from gun (6 MeV)
April 5: First e- to gun spectrometer (6 MeV)
April 8: First e- to inj-spectrometer (127 MeV)
April 9: First e- in linac to TD11 dump (127 MeV)
April 14: First 250-MeV beam through BC1
Up to ~330 pC of charge (370 µJ laser energy)
10 Hz beam & 30 Hz RF (30 Hz e- also tested)
Gun RF feedback running well (+ water)
April 16, 2006
LCLS FAC
3
Paul Emma
[email protected]
Pre-Beam Tunnel Check List Almost Complete
40 pages, ~2000 checks – all DONE (except a few missing screens)
Polarity conventions
Field type (quad, dipole)
Serial numbers
Installation orientation
etc.
April 16, 2006
LCLS FAC
4
Paul Emma
[email protected]
RF Processing of L0b (20-8)
March 25
March 10
Thanks to R. Akre & AMRF
April 16, 2006
LCLS FAC
5
Paul Emma
[email protected]
Gun Temperature Feedback Loop
Gun Temperature
Gun RF Probes
RF On
RF Off
RF On
Thanks Phil Cutino, Claudio Rivetta, Joe Frisch
April 16, 2006
LCLS FAC
6
Paul Emma
[email protected]
Gun RF Power (30 Hz)
18
16
14
RF Power (MW)
Time laser
here with
diode
Gun RF
coupler
(input
power)
12
Gun RF
probe (cavity
power)
11
Gun FWD Power
Gun RFL Power
MW
(~120
Gun RF
Probe MV/m)
10
8
Gun Reflected Power
6
1.2 µsec
4
2
0
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
Time (microseconds)
April 16, 2006
LCLS FAC
7
Thanks
Arnold Vlieks
Paul Emma
[email protected]
Virtual Cathode (optical image of laser spot on cathode)
April 16, 2006
LCLS FAC
8
Paul Emma
[email protected]
Beam on YAG02 (80 cm from gun)
20 mm
April 16, 2006
LCLS FAC
9
Paul Emma
[email protected]
Laser Phase (Shottky) Scan
50 µJ laser energy
30º
April 16, 2006
LCLS FAC
10
Paul Emma
[email protected]
Beam on Gun Spectrometer
5.7 MeV
April 16, 2006
LCLS FAC
11
Paul Emma
[email protected]
Beam to Injector Spectrometer
135 MeV
Steering was easy with few correctors on strong
energy
BPMs worked almost immediately!
GUN
April 16, 2006
LCLS FAC
SDMP
12
Paul Emma
[email protected]
Trajectory to TD11 (in main linac)
BC1 energy BPM
DL1 energy BPM
BPMs worked almost immediately!
April 16, 2006
LCLS FAC
13
BC1
BPM
Paul Emma
[email protected]
TD11
old
BPM
old
BPM
GUN
Spect. BPM X Reading after Bend (mm)
L0a RF Phase Scan on Dispersed BPM X
high energy
L0a RF phase (deg-S)
April 16, 2006
LCLS FAC
14
Paul Emma
[email protected]
Bunch Charge vs. Laser Energy
330 pC
370 µJ at
cathode
calibrations need confirmation
Iris cut clips laser energy
April 16, 2006
LCLS FAC
15
Paul Emma
[email protected]
EPICS Controls - Vacuum
Manual valve
April 16, 2006
LCLS FAC
16
Paul Emma
[email protected]
EPICS Controls - Magnets
April 16, 2006
LCLS FAC
17
Paul Emma
[email protected]
EPICS Controls – Profile Monitors
April 16, 2006
LCLS FAC
18
Paul Emma
[email protected]
Long Ion Chamber Along Full Accelerator
YAGS2 inserted
YAG03 inserted
April 16, 2006
LCLS FAC
19
Paul Emma
[email protected]
Charge and Position Jitter – Shot to Shot
X-position jitter is 10 µm rms
Charge jitter is 2.6% rms
2%
20 µm
100 shots at 10 Hz using BPM immediately after gun
April 16, 2006
LCLS FAC
20
Paul Emma
[email protected]
BC1 Chicane Control and Compression
BC1 BPM X (mm)
Ceramic Gap Bunch Length Monitor
RF phase: +40º
Slope = 1
250 MeV
when X = 0
BC1 X-Mover (mm)
BPM offset checked using BC1
collimator jaws to locate beam in X
RF phase: 0º
RF phase: -40º
April 16, 2006
LCLS FAC
OTR screen still needs camera
21
Paul Emma
[email protected]
Problems/Issues
Gun Faraday cup broken (pneumatic error)
Gun toroid shorted during installation
Gun z-position not right yet (7.5-mm interference)
YAG screens not setup before installation (hard-stops)
Still need to install cameras and air lines for 7 screens
No toroids working yet (1 shorted, 3 left to install)
BC1 motion control limited (300 mm  260 mm)
QE about 4-times lower than design (to be verified)
Some controls tools late (orbit displays & fitting)
MCOR power supply ADC readback noise (~1%)
April 16, 2006
LCLS FAC
22
Paul Emma
[email protected]
LCLS FAC
http://wwwssrl.slac.stanford.edu/lcls/internals/commissioning/documents/l
clsinjector-commissioninggoals.doc
2007 Injector Commissioning Goals
April 16, 2006
23
Paul Emma
[email protected]
Summary
Beam transported to all areas (no trouble)
No obstructions or ‘backwards’ components, etc
(but no systematic checkout yet)
Controls still developing, but working well and
improving fast – great cooperation and effort
Communication with laser group excellent
Screens and toroids late, but installation continues
Some quality control issues with a few components
Thanks to all – First indications are very positive
April 16, 2006
LCLS FAC
24
Paul Emma
[email protected]