![Page 1: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/1.jpg)
BROOKHAVEN SCIENCE ASSOCIATES
BIW’06
Lepton Beam Emittance Instrumentation
Igor PinayevNational Synchrotron Light Source
BNL, Upton, NY
![Page 2: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/2.jpg)
2 BROOKHAVEN SCIENCE ASSOCIATES
Outline
• Motivation and Definitions• Invasive methods
• Three screens• Wire scan• Quadrupole and solenoid scan
• Non-invasive methods• Visible light imaging• Pinhole camera• Imaging with zone plate• Interferometric method• Undulator radiation• Optical diffraction radiation
• Conclusions
![Page 3: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/3.jpg)
3 BROOKHAVEN SCIENCE ASSOCIATES
Emittance Definition
• Emittance is a measure of area occupied by a beam in phase space
• It affects major operational parameter: brightness, luminosity, gain length, coherency, etc.
222 '' xxxxx
x’
Area =
For uncoupled beam
maxx
x
max'x
slope
The invariant emittance ellipse is given by
)(
)(1)(
2
(s)'-(s)
where
')(')(2)(
2
22
s
ss
xsxxsxs
![Page 4: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/4.jpg)
4 BROOKHAVEN SCIENCE ASSOCIATES
Matrix Gymnastics
0
0
1
1
x
x
SC
SC
x
x
0
0
1
1
10
1
x
xL
x
x
0
0
11
1
1
01
x
x
x
x
f
0
22
22
12
2
SSCC
SSCSSCCC
SCSC
Particle propagating from point to another
can be described by the transport matrix
Twiss parameters transform as follows
For drift space with length L
For thin lens
![Page 5: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/5.jpg)
5 BROOKHAVEN SCIENCE ASSOCIATES
Three Screens Method
2
22
1
21
0
20
11
11
SC
SC
22
22
SC
SC
•Requires long drift space•Sensitive to optical magnification errors•Space charge effects can be significant•Shot-to-shot variations
S0 S1S2
2211
2221
222
2
2222,1
220
2222,1
20
1
1
2
2
0
1
0
2
2,1
2,1
2,1
2,1
0
2,1
2,1
2,1
2,1
2,1
0
2,1
where
4
4
1
SCSC
SS
S
S
SC
SC
SC
SC
SC
SC
![Page 6: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/6.jpg)
6 BROOKHAVEN SCIENCE ASSOCIATES
Wire Scan
![Page 7: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/7.jpg)
7 BROOKHAVEN SCIENCE ASSOCIATES
Factors Affecting Accuracy of Wire Scan
22
4
wire
beammeas
d• tilt angle of wire• dispersion in transfer line• beam jitter• scan non-uniformity
2
EE
xxxx
![Page 8: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/8.jpg)
8 BROOKHAVEN SCIENCE ASSOCIATES
Quadrupole Scan
• Beam parameters are extracted from the dependence of observed beam size vs. quadrupole strength
• Change in the upstream quadrupoles strength may be required because quadrupole focuses in one plane and defocuses in another
Quadrupole (0, 0, 0)
beam
Screen (S)
![Page 9: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/9.jpg)
9 BROOKHAVEN SCIENCE ASSOCIATES
Extracting Data from the Quadrupole Scan
For the thin quadrupole and drift with length L transport matrix is
0
0
1
1
11
1
x
x
f
LfL
x
x
L
aaaε
afLafLa
LLfLfL
LLfLfLS
4
is emittance the
)1()1(
fitparabolicthefrom
)1(2)1(
and
)1(2)1(
2120
012
22S
02
0022
S
02
002
![Page 10: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/10.jpg)
10 BROOKHAVEN SCIENCE ASSOCIATES
Solenoid Scan
• Similar to the quadrupole scan• Solenoid introduces beam rotation
(coupling)• Low energy• Radial symmetry can be usedGun Solenoid
Screen
2
01
cos0sin0
0cos0sin
sin0cos0
0sin0cos
T
where
done becan decoupling
mc
eBL
TRR
T
RR T
![Page 11: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/11.jpg)
11 BROOKHAVEN SCIENCE ASSOCIATES
Imaging with Visible Radiation
• Used mostly for storage rings with well known -functions• Versatile and easily realized• Can be used for real-time beam measurements
Synchrotron radiation
Iris Lens Bandpass
filter
Neutral
filter
CameraMirror
10025
540022.122.1
mm
mnm
D
LL phres
•Source length should be accounted for
•Mirror should provide minimal distortion under the heat load
![Page 12: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/12.jpg)
12 BROOKHAVEN SCIENCE ASSOCIATES
Pinhole Camera
2122222pinholendiffractiocamerascreenx
wD
ddDw
ndiffractio
pinhole
412
1221
21
At ESRF 10 μ pinhole provides resolution of 13 μ for beam size
![Page 13: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/13.jpg)
13 BROOKHAVEN SCIENCE ASSOCIATES
Imaging with Fresnel Zone Plate
source
double crystal monochromator
zone plate screen
• Monochromator is required due to the strong chromatic aberrations of zone plate
• SPring-8 achieved 4 μ resolution for beam size with the help of X-ray zooming tube
• Observed transient in the beam size during top-off operation
![Page 14: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/14.jpg)
14 BROOKHAVEN SCIENCE ASSOCIATES
Laser “Wire”
• Replaces solid “wire” with laser beam• Can reach micron level resolution (waist 12 μ)
![Page 15: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/15.jpg)
15 BROOKHAVEN SCIENCE ASSOCIATES
Laser “Harp”
• Standing wave interference pattern is generated by two crossing laser beams
• Electron beam is moved across the pattern and modulation in the intensity of Compton scattered photons is observed
2
2expcos2sin2 dNN
NNd
![Page 16: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/16.jpg)
16 BROOKHAVEN SCIENCE ASSOCIATES
Interference Method
• Similar to Michelson stellar interferometer• Measures dependence of contrast of interference
fringes on slit separation
2
minmax
minmax 2expL
D
II
II x
For Gaussian beam
![Page 17: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/17.jpg)
17 BROOKHAVEN SCIENCE ASSOCIATES
Set-up KEK-ATF
![Page 18: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/18.jpg)
18 BROOKHAVEN SCIENCE ASSOCIATES
Undulator Radiation
222
2 212
KnU
n][][934.0 TBcmK U
222
222
unde
unde
ph
ph
screen
The nth harmonic wavelength
Uund
Uund L
L
24
2
2
2222
l
lundscrl
Emittance of 0.2 nm was measured with 30 keV X-ray photons
lUndulator (LU)
![Page 19: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/19.jpg)
19 BROOKHAVEN SCIENCE ASSOCIATES
Undulator Spectrum
RMS
E
Energy
FWHM
x
Emittance
FWHMUNat
EnergyEmittanceDetectorNat
E
K
nN
2
21
1
2
22
2222
![Page 20: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/20.jpg)
20 BROOKHAVEN SCIENCE ASSOCIATES
Calculated vs. Measured
200x109
150
100
50
Phot
/s/0.
1%bw
5800eV5600540052005000480046004400
Photon Energy
120x109
100
80
60
40
20
0Ph
ot/s/
0.1%
bw
7800eV760074007200700068006600
Photon Energy
100x109
80
60
40
20
Phot
/s/0.
1%bw
9500eV90008500
Photon Energy
SRW
Cal
cula
tions
Mea
sure
d
780 800 820 840 860 880
50
100
150
200
250
300
350
400
450
Flux from X25 through 30x50 um at 26.1 for diff. coupling
1
00.5
520 540 560 580 600 620 640 660 680
100
200
300
400
500
600
700
Flux from X25 through 30x50 um at 26.1 for diff. coupling
1
00.5
360 380 400 420 440 460 480 500
50
100
150
200
250
300
350
400
450
Flux from X25 through 30x50 um at 26.1 for diff. coupling
1
00.5
34 5
![Page 21: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/21.jpg)
21 BROOKHAVEN SCIENCE ASSOCIATES
Optical Diffraction Radiation
2
h
=2500 y=0, 30 μm
Dependence of contrast
vs. beam size at different
wavelengths
![Page 22: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/22.jpg)
22 BROOKHAVEN SCIENCE ASSOCIATES
Conclusions
• The emittance measurement technique became state-of-the-art capable to satisfy most requirements
• Wide variety of methods is used• Some methods require thorough theoretical
consideration• Some has experimental complexity• New methods will appear as improvements in beam
quality will require more precise instrumentation
![Page 23: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/23.jpg)
23 BROOKHAVEN SCIENCE ASSOCIATES
mrad = meter·radian
![Page 24: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/24.jpg)
24 BROOKHAVEN SCIENCE ASSOCIATES
Optical Klystron Spectrum
• Spectrum is interference of two wave packets
• Fringes visibility is defined by energy spread
• Only longer wavelength part of the spectrum is affected by non-zero emittance
• Horizontal emittance is obtained
Undulator 1 Undulator 2Buncher
![Page 25: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/25.jpg)
25 BROOKHAVEN SCIENCE ASSOCIATES
![Page 26: BROOKHAVEN SCIENCE ASSOCIATES BIW ’ 06 Lepton Beam Emittance Instrumentation Igor Pinayev National Synchrotron Light Source BNL, Upton, NY](https://reader035.vdocuments.site/reader035/viewer/2022070410/56649ebf5503460f94bca149/html5/thumbnails/26.jpg)
26 BROOKHAVEN SCIENCE ASSOCIATES
wire
beam scan
bend
beam
detector
WS
a) b)
S0 S1 S2
x’
Area =
maxx
x
max'x
slope
source
screenmask
L