1. Emittance Diagnostics
Coupling Correction and Emittance Diagnostics for the ATF2 Extraction Line
Coupling Correction /
Emittance Diagnostics
FONT
nBPM (KEK)
nBPM (SLAC)
ATF Extraction Line
ODR
Compton / laserwire
April 5, 2005
ILC BDS Meeting

2. Coupling Correction ideally
correction section with 4 independent skew quadrupoles, followed by
2D (4 wire scanner) emittance measurement section
optics for orthogonal control of the 4 coupling phases
minimize εy once with each skew quadrupole
in present ATF extraction line
non-optimal optics in EXT straight section
wire scanners and skew quads interspersed
each wire scanner has x, y, and “u/v” (small angle, ~10°) wires
one attempt at full 4D beam matrix measurement and correction was inconclusive4
4 See
April 5, 2005
ILC BDS Meeting

3. “Ideal” skew correction / ε diagnostic sectionSQ SQ SQ SQ WS WS WS WS
– x
– y
90°
180°
90°
90°
45°
45°
45°
See
April 5, 2005
ILC BDS Meeting

4. – x – y L = 11.43 m April 5, 2005 ILC BDS Meeting 5° 8° 13° 20° 30°WS WS WS WS WS SQ SQ SQ SQ
– x
– y
L = m 5° 8°
13°
20°
30°
36°
April 5, 2005
ILC BDS Meeting

5. – x – y L = 20.58 m ΔL ≈ 10 m σWS > 5 μ April 5, 2005SQ SQ SQ SQ
1.2
1.2
1.7
1.7
1.1
1.3
1.1
0.9
0.9
0.9
0.7
1.3
1.1 WS WS WS WS WS
– x
– y
L = m
ΔL ≈ 10 m
32°
48°
51°
21°
32°
58°
58°
32°
σWS > 5 μ
April 5, 2005
ILC BDS Meeting

6. – x – y L = 15.80 m ΔL ≈ 5 m April 5, 2005 ILC BDS Meeting 31° 40° 41°SQ SQ SQ SQ
0.8
0.7
1.7
1.7
0.6
0.8
0.6
0.5
0.5
0.5
0.3
0.8
0.6 WS WS WS WS WS
– x
– y
31°
40°
41°
13°
32°
58°
58°
32°
L = m
ΔL ≈ 5 m
April 5, 2005
ILC BDS Meeting

7. A ‘Drift’ e-Diagnostic Section
from Paul Emma … b s L w1 w2 w3
3 wire scanners (or profile monitors)
April 5, 2005
ILC BDS Meeting

8. – x
– y
σmin = 3 μ
April 5, 2005
ILC BDS Meeting

9. Emittance Growth in ILC Upstream Polarimeter/Spectrometer Chicanes
April 5, 2005
ILC BDS Meeting

10. γε/γε0 = 9.610-6 η5
April 5, 2005
ILC BDS Meeting

11. April 5, 2005
ILC BDS Meeting