EXT: Summary of activities,
software development,
and tuning performance
11th ATF2 Project Meeting, January 13 2011
M. Woodley
1/29
ATF / ATF2 Schematic Layout
Final
Doublet
Final Focus
β-match
Emittance
Measurement
5 × WS, 4 × OTR
10 μ W wires
(x/y/+10°/-10°)
Coupling
Correction
Dump
Inflector
Laserwire
EXT
INJ
Laserwire
PIP WS
IPBSM
10 μ W wires 10 μ W wires
(x/y/45°)
(x/y)
5 μ C wires
5 μ C wires
(y/+1.3°/-1.3°)
(x/y)
screen
Damping
Ring
FOBO
Beam
Transport
XSR
eS-band
RF Gun
1.3 GeV S-band Linac
120 m
11th ATF2 Project Meeting, January 13 2011
M. Woodley
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Outline
• EXT tuning
– dispersion correction
– emittance measurement
– coupling correction
• vertical emittance issues
– extraction kicker voltage
– DR orbit & extraction trajectory
• EXT / FF BBA results
• EXT Laserwire / ATF2 compatibility mode optics
• magnet TRIM function issue
• Summary and Continuing Work
11th ATF2 Project Meeting, January 13 2011
M. Woodley
3/29
EXT Tuning
OTR0X before
corrections
11th ATF2 Project Meeting, January 13 2011
OTR0X after
dispersion correction
M. Woodley
OTR0X after
coupling correction
4/29
Dispersion Correction
11th ATF2 Project Meeting, January 13 2011
M. Woodley
5/29
Flight Simulator Dispersion Package GUI
11th ATF2 Project Meeting, January 13 2011
M. Woodley
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Dispersion Correction (December 7, 2010)
Before Correction
After Correction
beam must be centered in QF1X/QF6X/QS1X/QS2X
11th ATF2 Project Meeting, January 13 2011
M. Woodley
7/29
KEX2
QD8X
QF7X
BH3X
QF6X
BH2X
QD5X
QF4X
QF3X
QD2X
BH1X
QF1X
BS3X
BS2X
QM7R
BS1X
QM6R
KEX1
QS1X
Vertical Dispersion Correction
(FD-phase)
QS2X

1/2
20
10
X
Y
0.75
0.5
0.25
0
-0.25
-0.5
-0.75
1


0
0
-1
0
5
10
15
20
S (m)
“Sum-Knob”: IQS1X = IQS2X
Δ Sum-Knob = -0.15 A
IP-phase
FD-phase
Simulated ηy* (right) and η'y* (right),
back-propagated from IP
11th ATF2 Project Meeting, January 13 2011
M. Woodley
8/29
Emittance & Coupling
Measurement & Correction
11th ATF2 Project Meeting, January 13 2011
M. Woodley
9/29
EXT Emittance Measurement (OTR)
OTR
0
15
OTR
1
OTR
2
20°
8.5
WS
3
 34 

   33
 ,  34   43


44 
 43
OTR
3
28°
7.2
WS
4
QM16FF
WS
2
QF21X
WS
1
QD20X
WS
0
QF19X
QD18X
EXTEXT
Diagnostic
Section Section
(version 4.2b)
Diagnostic
Δψ
σ (μm)
46°
11.4
7.3
 n   R0n  0  R0n 
T
Vertical Beam Size (um)
Ax  b
0
x   330  43
 440 
10
T
T
5
1
b   330  33
 332  333 
0
0 
 1
 01 2

01 01
01 2
  R33  2 R33 R34  R34  

A   02 2
2
 R33  2 R3302 R3402  R3402  


2
2
03
03
03
03
 R  2 R R
 R34  
33 34
 33
R01
R02
R03
0
38
40
42
44
46
48
50
52
S (m)
11th ATF2 Project Meeting, January 13 2011
M. Woodley
10/29
Fast Automatic Emittance Measurement with OTRs
• horizontal beam size too big for OTR … Gaussian fits to projection not so good
– new camera lens with less magnification? (loss of resolution)
– variable magnification lens?
• ellipse fit parameters sensitive to background subtraction, windowing, etc.
– use standard image analysis techniques from light optics (laser folks are familiar with this)
– ellipse fit parameters can be used to compute projected sizes … compare to direct Gaussian fits
11th ATF2 Project Meeting, January 13 2011
M. Woodley
11/29
QK Optimization (Dec 13, 2010)
11th ATF2 Project Meeting, January 13 2011
M. Woodley
12/29
QK Optimization (Dec 13, 2010)
DR XSR:
εy = 14.1 pm
before:
QK1X = -5.9
QK2X = 0
QK3X = 0
QK4X = -5.0
εy = 40.4 pm
after:
QK1X = -15.7
QK2X = -1.8
QK3X = 1.3
QK4X = 1.3
εy = 33.9 pm
11th ATF2 Project Meeting, January 13 2011
M. Woodley
13/29
Horizontal EXT Emittance Measurements
Vertical EXT Emittance Measurements
Date
Date
Nwire
Emit (nm)
BMAG
Dec 14 2010
4
1.784 ± 0.130
1.10 ± 0.04
Dec 14 2010
5
27.6 ± 1.8
1.09 ± 0.04
Dec 9 2010
4
1.686 ± 0.102
1.08 ± 0.05
Dec 9 2010
4
29.3 ± 3.1
1.05 ± 0.02
Nov 2010 (?)
EXT kicker controller replaced
Nov 2010 (?)
EXT kicker controller replaced
Nwire
Emit (pm)
BMAG
May 18 2010
4
1.905 ± 0.078
1.08 ± 0.03
May 18 2010
5
11.7 ± 2.3
1.43 ± 0.25
Apr 21 2010
4
1.212 ± 0.065
1.26 ± 0.03
Apr 21 2010
5
15.4 ± 2.0
1.78 ± 0.17
Mar 17 2010
Feb 25 2010
BS3X rolled ~4 mrad (CCW)
4
1.868 ± 0.336
Feb 17 2010
4
negative
Feb 3 2010
4
1.626 ± 0.095
Mar 17 2010
1.15 ± 0.12
1.10 ± 0.06
Jan 28 2010
11th ATF2 Project Meeting, January 13 2011
M. Woodley
BS3X rolled ~4 mrad (CCW)
Feb 25 2010
5
22.08 ±0.9
1.19 ± 0.03
Feb 25 2010
5
38.33 ± 1.1
1.10 ± 0.02
Feb 17 2010
5
22.6 ± 1.4
1.15 ± 0.04
Feb 3 2010
5
16.1 ± 0.7
1.06 ± 0.03
Jan 28 2010
5
31.6 ± 1.2
1.03 ± 0.01
14/29
Emittance & Coupling
DR Orbit & Extraction Trajectory
11th ATF2 Project Meeting, January 13 2011
M. Woodley
15/29
SET-file History (Apr-Dec, 2010)
Dec 14
εy = 27.6 pm
4
DKICKER
5
x 10
Apr 21
εy = 15.4 pm
May 18
εy = 11.7 pm
KEX controller
replaced
4
Dec 9
εy = 29.3 pm
BS1X
3
1600
1500
BS3X
2650
2600
2550
ZH9R
2500
0
-1
BKX
-2
10
fast
kicker
5
0
Apr
May
11th ATF2 Project Meeting, January 13 2011
Jun
fast
kicker
Jul
Oct
M. Woodley
Nov
Dec
Jan
16/29
QM19R1
QM18R1
QM17R1
QM16R1
QM15R1
QM14R1
QM13R1
QM12R1
QM11R1
QM10R1
QM9R1
QM8R1
QM7R1
QM6R1
KEX1
QM5R1
ATF DR: North Straight Section
septum
4
X (mm)
2
0
-2
-4
25
Preliminary Result
30
35
40
45
3
Apr 21
May 18
Dec 9
Dec 14
Y (mm)
2
1
0
-1
25
11th ATF2 Project Meeting, January 13 2011
30
35
S (m)
M. Woodley
40
45
17/29
BBA
11th ATF2 Project Meeting, January 13 2011
M. Woodley
18/29
EXT BBA
ATF2 BBA (10nov11)
MQF1X
MQD2X
MQF3X
MQF4X
MQD5X
MQF6X
MQF7X
MQD8X
MQF9X
FONTP1
MQD10X
MQF11X
FONTP2
MQD12X
MQF13X
MQD14X
FONTP3
MQF15X
MQD16X
MQF17X
MQD18X
MQF19X
MQD20X
MQF21X
-1500
x
y
-1000
11th ATF2 Project Meeting, January 13 2011
-500
0
BBA Offset (um)
M. Woodley
500
1000
1500
19/29
FF BBA
ATF2 BBA (10dec10)
x
y
QM15FF
QM14FF
QM13FF
QM12FF
QM11FF
QD10BFF
QD10AFF
QF9BFF
SF6FF
QF9AFF
QD8FF
QF7FF
QD6FF
QF5BFF
QF5AFF
QD4BFF
QD4AFF
QF3FF
QD2BFF
QD2AFF
SD0FF
-1500
-1000
11th ATF2 Project Meeting, January 13 2011
-500
0
BBA Offset (um)
M. Woodley
500
1000
1500
20/29
EXT Laserwire / ATF2
Compatibility Optics
11th ATF2 Project Meeting, January 13 2011
M. Woodley
21/29
Beta (m)
0
160 25
140
80
0
25
30
(L. Deacon)
0.1 m βLW
30
sqrt(Beta)
40
x
y
BetaX=2.930, BetaY=0.100 (m)
35
35
40
40
11th ATF2 Project Meeting, January 13 2011
QF21X
QD20X
QF19X
QD18X
QK4X
QF17X
QK3X
QD16X
QF15X
QD14X
QF13X
QK2X
QD12X
45
45
60
10
20
50
120
30
100
25
60
15
40
10
20
5
S (m)
50
M. Woodley
0
EXT Laserwire Optics
15
EXT Laserwire + BX10BY10 Optics
S (m)
0
40 0
10
35
x
y
0
10
20
20
30
30
40
40
QM16FF
QM15FF
QM14FF
QM13FF
QM12FF
QM11FF
QD10BFF
QD10AFF
QF9BFF
SF6FF
QF9AFF
QD8FF
QF21X
QD20X
QK1X
QD10X
QF11X
QK2X
QD12X
QF13X
QD14X
QF15X
QK3X
QD16X
QF17X
QK4X
QD18X
QF19X
QD8X
KEX2
QF9X
S (m)
20
50
60
70
80
50
60
70
80
SF1FF
QF1FF
SD0FF
QD0FF
SF1FF
QF1FF
SD0FF
QD0FF
B2FF
QF3FF
B1FF
QD2BFF
QD2AFF
20
B2FF
QF3FF
B1FF
QD2BFF
QD2AFF
x
y
QF7FF
B5FF
QD6FF
QF5BFF
SF5FF
QF5AFF
QD4BFF
SD4FF
QD4AFF
40
QF7FF
B5FF
QD6FF
QF5BFF
SF5FF
QF5AFF
QD4BFF
SD4FF
QD4AFF
25
QM16FF
QM15FF
QM14FF
QM13FF
QM12FF
QM11FF
QD10BFF
QD10AFF
QF9BFF
SF6FF
QF9AFF
QD8FF
100
QF21X
30
QD20X
120
QF4X
QD5X
BH2X
QF6X
QS2X
BH3X
QF7X
KEX1
QM6R
QM7R
BS1X
BS2X
BS3X
QS1X
QF1X
BH1X
QD2X
QF3X
QF21X
QD20X
QF19X
QD18X
QK4X
QF17X
QK3X
QD16X
QF15X
QD14X
QF13X
QK2X
QD12X
QF11X
QK1X
QD10X
QF9X
EXT Laserwire Optics
QK1X
QD10X
QF11X
QK2X
QD12X
QF13X
QD14X
QF15X
QK3X
QD16X
QF17X
QK4X
QD18X
QF19X
35
QD8X
KEX2
QF9X
x
y
BetaX=0.461, BetaY=0.300 (m)
QF4X
QD5X
BH2X
QF6X
QS2X
BH3X
QF7X
0.3 m βLW
sqrt(Beta)
160
KEX1
QM6R
QM7R
BS1X
BS2X
BS3X
QS1X
QF1X
BH1X
QD2X
QF3X
80
QF11X
140
QK1X
QD10X
QF9X
Beta (m)
EXT LW / ATF2 Compatibility Optics
EXT Laserwire + BX10BY10 Optics
5
S (m)
22/29
EXT LW / ATF2 Compatibility Optics
QF21X
QD20X
QF19X
QD18X
QK4X
QF17X
QK3X
QD16X
QF15X
QD14X
QF13X
QK2X
QD12X
QF11X
QF9X
QF21X
600
QK1X
QD10X
EXT Laserwire Optics
QD20X
QF19X
QD18X
QK4X
QF17X
QK3X
QD16X
QF15X
QD14X
QF13X
QK2X
QD12X
QF11X
QK1X
QD10X
QF9X
EXT Laserwire Optics
80
SigX1 = 30.4 um
SigX2 = 76.6 um
500
SigY1 = 2.4 um
SigY2 = 1.4 um
70
εx = 2 nm
εy = 20 pm
60
400
SigY (um)
SigX (um)
50
300
40
30
200
20
100
10
0
25
30
35
40
45
50
0
S (m)
11th ATF2 Project Meeting, January 13 2011
25
30
35
40
45
50
S (m)
M. Woodley
23/29
EXT LW / ATF2 Compatibility Optics: some notes
• optics requires polarity flip for QM16FF and QM11FF
• backgrounds for both LW and BSM could be made acceptable
– relaxed FF optics (“BX10BY10”)
– FF sextupoles OFF
• laser / e- beam collisions found (βyLW = 0.3 m optics)
• beta-match to LW waist after emittance measurement … failed … cockpit error
• βyLW = 0.1 m optics not tested yet
• matching to other FF optics (i.e. “BX2.5BY1”) is OK, too
• see Laura Corner’s talk …
11th ATF2 Project Meeting, January 13 2011
M. Woodley
24/29
Magnet Trim Function Issue
• most magnets have “standard” SET/trim functionality
– enter a new SET value
– magnet trims from present value to new value
• some magnets seem to have special SET/trim functionality (for trim rate control?)
– enter a new SET value
– SET value increments/decrements from present value to new value in some number of steps
– at each step, magnet trims from present value to new SET value for that step
• sometimes this process aborts before reaching the final desired SET value
– SET value is left at an intermediate value
– there’s no way to know that the magnet now has the wrong SET value
• QK1X (Dec 15 2010 04:00)
– original SET value was -15.7 amp (after coupling correction … εy = 34 pm)
– magnet strength was scanned from -10.7 amp to +10.3 amp (IP spot size tuning)
– magnet was reset to -15.7 amp … trimming aborted … SET value was left at +1.5 amp
– coupling correction was destroyed (a subsequent OTR emittance measurement gave εy = 54 pm)
– all subsequent IP spot size tuning was made with QK1X @ +1.5 amp!
11th ATF2 Project Meeting, January 13 2011
M. Woodley
25/29
Summary &
Continuing Work
11th ATF2 Project Meeting, January 13 2011
M. Woodley
26/29
Summary (1)
• Flight Simulator dispersion measurements
– fully automatic control of DR RF ramp
– propagated dispersion values at wire scanners, OTRs, etc. now available to other FS packages
– jitter-based (SVD) measurement still under investigation
• model-based horizontal dispersion correction (ηx and η'x) works
– good BBA offset measurements for QF1X/QF6X are critical
– beam must be centered in QF1X and QF6X for proper correction
– no empirical fudge factors required
• vertical dispersion correction is still done manually
– sum knob (QS1X=QS2X) is adjusted to minimize FD-phase ηy
• fast OTR emittance measurements are now available
– magnification changes to widen horizontal field of view (better horizontal projected fits)
– address sensitivity of ellipse fit to background, windowing, etc. (done, I think ... )
11th ATF2 Project Meeting, January 13 2011
M. Woodley
27/29
Summary (2)
• full QK-scan minimization of BMAGy*εy demonstrated
– ~ 2 hours for full correction
– minimum εy ~ 2x the DR XSR measured value
– can now envision repeating scans to verify orthogonality of skew correction system
• beam extracted from DR seems to have both εy growth and coupling
– KEX voltage? DR orbit? steering in septum region?
• BBA offsets have been measured for most BPMs
• optics has been developed and tested for simultaneous EXT LW and BSM operation
– compatibility mode operation with “BY1” optics and IP spot size tuning not yet tested
11th ATF2 Project Meeting, January 13 2011
M. Woodley
28/29
Continuing Work
• FS dispersion package
– automate ηy correction
– continue to study non-invasive jitter-based (SVD) dispersion measurement
• coupling measurement / 4D beam reconstruction
– use OTR ellipse fit to extract lengths of semi-major and semi-minor axes and tilt angles
– revisit 4D reconstruction … try Ilya Agapov’s “Cholesky decomposition” method?
• DR orbit / extraction trajectory / εy / coupling
– need EPICS access to DR BPMs (closed orbit & extraction buffer)
– check dependence of εy and coupling on DR orbit (i.e. vertical offset/angle at KEX1)
– save orbits more frequently!
• and ...
11th ATF2 Project Meeting, January 13 2011
M. Woodley
29/29