EMMA commissioning
Bruno Muratori (for the EMMA team)
STFC, Daresbury Laboratory
02/09/08
Overview
• What is commissioning ?
– Preparing machine for beam
• set-up DAQ & controls & hardware
• set-up diagnostic devices required
– Getting beam into the machine & where you want it
– Making sure all desired properties are achieved
• for the bunch (full characterisation etc.)
• for the machine (e.g. dispersion-free sections)
– Set-up machine for particular experiments
– Need as many simulations of the machine as possible !
ALICE commissioning (1)
I. Gun commissioning
- complete (December 2007)
II. First energy recovery
- will start now (September 2008) !
- all procedures are ready (in Wiki)
- online modelling (Mathematica based), being
currently developed
- get the energy recovery without FEL first
III. Machine tuning
- fine beam tuning
- phase space manipulation to achieve minimal bunch
length
- full beam characterisation
- EO bunch length measurements
ALICE commissioning (2)
IV. Energy recovery with FEL
- first light from FEL
- energy recovery of FEL disrupted beam
- commissioning complete
V. ALICE exploitation
- CBS experiments
- tomography with space charge (in EMMA injection line)
- other experiments (e.g. linac transfer matrices
measurement)
- preparations for EMMA commissioning
ALICE schematic
ERLP SCHEMATIC DIAGRAM
v.0.2 (15/06/2006)
extracted from AO-180/10078/E
FCUP-01
YAG-??
INJ
EC
TO
R
Q-07
Q-09
Q-08
DIP-3
Q-06
DIP-02
Q-10
DIP-01
Q-05
YAG-03
Q-04
H&V-03
YAG-02
ST4
YAG-04
ARC 2
OTR-01
Q-01 Q-02 Q-03 Q-04 Q-05
BPM-06
DIP-03
Q-03
BPM-03
Q-02
BPM-05
SEXT-02
OTR-02
Q-04
BO
OS
TE
R
Q-01
H&V-06
H&V-01
BPM-02
SOL-02
YAG-01
BUNCHER
BPM-01
GU
N
BPM-01
H&V-01
Q-12
BPM-01
OTR-01 H&V-01
OTR-02 DIP-01
DIP-03
DIP-02
Q-01
BPM-02
H&V-02
Q-02
Q-03
LINAC
OTR-02
BPM-02 DIP-01 DIP-02 DIP-03
H&V-02
OTR-03
DUMP-01
DMP
BPM-01
Q-01
Q-02
ARC1
1m
Q-04
BPM-01
DIP-01
BPM-02
OTR-04
SEXT-01
OTR-01
Q-01
Q-03
V-01
Q-02
OTR-01
BPM-03
Note: scale is for guidance only
DIP-02
DIP-02
BPM-03
BPM-04
Q-02
V-01
Q-03
V-02
OTR-01
SEXT-01
BPM-02
DIP-01
BPM-01
BPM-02
H&V-02
OTR-01
BPM-03
DIP-03 V-03
DIP-02
BPM-01
H&V-01
Q-02 Q-01
Q-07 Q-06 BPM-04
H&V-04 Q-05
ST 3
Q-03
DIP-04
Q-04
DIP-01
BPM-02
H&V-02
OTR-02
BPM-01
H&V-01
OTR-01
OTR-03
WIGGLER
Q-04
ARC 2
SOL-01
ST1
V-02
Q-03
BPM-03
Q-01
H&V-02
ST1
Q-11 BPM-05
H&V-05
BPM-04
H&V-04
BPM-05 TCM-01
PLM-01
H&V-05
ST 3 ST 2
Q-04 Q-03
Q-02 Q-01
ST 2
OTR-02
SEXT-02
BPM-05
DIP-03
BPM-06
ARC1
• Need similar schematic for EMMA injection line, ring and
extraction line (shall be enormously more detailed … !)
Injection Line Commissioning (1)
• I Prepare ALICE as Injector for EMMA
– Set required beam energy (e.g. 10 MeV)
– Beam characterisation
• Bunch length / Charge / Emittance / Energy spread /
other ?
– Hardware commissioning
– Controls & online model commissioning
• These should be as comprehensive as possible
(within reason)
– DAS commissioning
Injection Line Commissioning (2)
Set initial charge at 1 pC
• II Thread beam through injector line
– Cancel dispersion in diagnostic straight
– Steering: use steerers & kickers to get beam to given
point & with right angle depending on energy and
required septum settings
– Beam characterisation (as much as possible – as
always !)
– Comparison with models wherever possible
Injection Line Commissioning (3)
• III EMMA ½ turn → extraction
– Threading beam without acceleration
– Threading beam with acceleration
– Characterisation of beam in both cases (extraction /
diagnostic line)
• IV EMMA 1 ½ turn → extraction
– Threading beam without acceleration
– Threading beam with acceleration
– Characterisation of beam in both cases (extraction /
diagnostic line)
Injection Line Commissioning (4)
• V EMMA 10 turn → extraction
– Same as before but
• In one go ?
• Step by step ? (i.e. one turn at a time)
– Characterisation of beam in all cases
Set nominal charge (q = 16 or 32 pC)
• VI Repeat all of the above
• VII EMMA exploitation
– Establish Orbit
– Tune measurements
– Aperture survey
Diagnostics:
injection line
ALICE
ALICE quadrupoles
last dispersive
section
SRS quadrupoles
New quadrupoles
Faraday Cup
Screen
EMMA
Diagnostics – injection line (1)
• OTR Screen in ALICE before extraction dipole
• BPMs @ entrance of every dipole in injection line
• Straight ahead Faraday cup to measure charge &
energy spread
• OTR screen in dogleg for bunch length & energy
measurement
• Tomography section: 60 degrees phase advance per
screen with three screens for projected transverse
emittance measurements
Diagnostics – injection line (2)
• Last dispersive section:
– OTR screen & vertical slit in middle of first section
together with
– OTR screen in final section for energy and energy
spread measurements
– Vertical steerers for position & angle before ring (to
be used with kickers for steering)
– BPM at entrance of EMMA ring for position before
entering
Online Modelling (1)
• Build on ALICE experience
– Gun commissioning
• Script to run ASTRA for comparisons / predictions
– Injection line
• Run GPT for space charge calculations in ALICE
• Script to run ELEGANT / other for remainder of
ALICE
– ALICE ring
• Script to run ELEGANT / GENESIS / other codes
for lasing etc.
Online Modelling (2)
• Create model of ALICE to EMMA injector line in GPT
– Run this model both on & off line for comparisons /
predictions
• Create S2E model for all of EMMA in GPT
– Run with field maps & misalignments for comparisons
/ predictions
– Run all the way to spectrometer & dump in the EMMA
extraction line
• Compare this with ZGOUBI models & FFEMMAG
models wherever possible
Online Modelling (3)
• Ring optics – what things may look like
courtesy S. Machida
Online Modelling (4)
• Injection orbit and optics - what things may look like
See orbit and optics
of incoming beam
Set septum and
kicker strength
courtesy S. Machida
EMMA Ring
Waveguide distribution
IOT
Racks (3)
Injection
Septum 65°
Kicker
Kicker
Wire Scanner
Extraction
Septum 70°
Screen
Kicker
Wall
Current
Monitor
Septum
Power
Supply
Kicker
Power
Supplies
Cavities
x 19
Screen
Kicker
Septum
Power
Supply
Kicker
Power
Supplies
D Quadrupole x 42
F Quadrupole x 42
Wire Scanner
BPM x 82
16 Vertical
Correctors
Establishing the orbit (1)
• Look at Beam Position Monitor (BPM) one by one from the
injection point (not symmetric → not straightforward)
• Adjust initial beam position (x,x’,y,y’) as well as Quad
current and position
BPM
Establishing the orbit (2)
• Double focusing lattice (QF and QD)
• Bend fields are created by shifting quadrupoles
• 4 knobs
– QF and QD strength
– QF and QD position
(horizontally)
QD
QF
• 4 parameters to fit
– Qx and Qy
– TOF shape and offset
Linear slide
Diagnostics:
extraction line
spectrometer dipole
ERLP
SRS quadrupoles
New quadrupoles
TD Cavity
EMMA
Diagnostic line
deflecting cavity
tomography
EO
spectrometer
NEW DIAGNOSTICS BEAMLINE LAYOUT
SRS Quadrupoles x 6
New Quadrupoles x 4
Screen
& Vert. Slit
BPM &
Valve
Screen x 3
Tomography
Section
Emittance measurement
Spectrometer Extracted momentum
BPM @ dipole entrance
Screen
Faraday Cup
Wall Current Monitor
E-O Monitor
Current measurement
Longitudinal profile
Location for Transverse
Deflecting Cavity
(NOT IN BUDGET)
Screen
ALICE
New Dipoles (43°)
& BPMs at dipole entrance
Position measurement
New Quadrupoles x 4
Measurements in diagnostic line
• Energy
– First dipole & spectrometer at end with OTRs
• Emittance
– Quadrupole scans & tomography 60° phase advance
/ screen
– Equivalent set-up in injection line for comparisons
• Bunch length
– EO monitor downstream of tomography
– No profile information
Measurements with TDC
• Slice emittance & transverse profiles given by
– knowledge of R12 from TDC to screen
R12   d  s sin 
 x1   R11
 ' 
 x1   R21
R12   x0 
 
R22  x0' 
– horizontal dimension on screen gives slice emittance
– vertical dimension gives bunch length
• Slice energy spread given by
– streaked beam and spectrometer
Experiments on EMMA
• Cross different large resonances
• Measurement of time of flight
– Change frequency until no synchrotron oscillations
– Frequency then translates into TOF
– Hence find minimum of TOF
• Relationship of TOF to lattice parameters / tune
– Tune vs. energy
• Study variation of all parameters to lattice properties
• Interpretation of BPM readings
– Not all identical & only symmetry every other cell
– Important to model all BPM readings → GPT / other
Aperture survey
• Phase space at injection
• Scan aperture in phase
space with a pencil beam
• See S. Tzenov’s talk for
more details

•
•
•
•
x’
pencil beam

 /
x


 /
When is normalized acceptance is 3 mm rad ?
Explore acceptance at all energies
Should also be modelled with FFEMMAG, GPT & others
To be done at all energies
from 10 to 20 MeV
Conclusions / Discussion
• Commissioning for EMMA will be a lengthy procedure !
• As many models as possible are required for all aspects
of the machine
– At all energies
– For all lattices
• These may be far from
perfect but should give
insight into the trend or
pattern of beam behaviour e.g. ALICE solenoid scan
• Online models should also be done where possible &
necessary
SOL-01 scan
Beam size (FWHM) on YAG "A"
Q = 54pC (#712)
20
SQRT (XY)
FWHM (Astra)
SQRT (XY), mm
15
10
5
0
300
320
340
360
B1, G
380
400