142 Beam-based Correction and Optimization for Accelerators
0
10
20
30
40
50
BPM index
-0.02
0
0.02
y
(rad)
ICA
HA w/ NAFF
Sine fit
-0.01
0
0.01
x
(rad)
Figure 5.10 Comparison of phase determination accuracy for three methods: ICA,
harmonic analysis with NAFF, and the sinusoidal fitting, using simulated data as
shown in Figures 5.4 and 5.7. Data consist of 256 turns of turn-by-turn orbits on 57
BPMs with BPM noise sigma of 10 µm. Oscillation amplitude is about 1 mm.
0
10
20
30
40
50
BPM index
4.8
5
5.2
y
10
-4
NAFF
Sine fit
5.8
5.9
6
x
10
-4
Figure 5.11 Betatron tune differences between the measurement and the model for
NAFF, the sinusoidal fitting method, and ICA (straight line).