1. PS2 Orbit Correction - Update Wolfgang Bartmann PS2 Meeting, 26 th March 09 26-Mar-091PS2 Orbit Correction - Update

2. Error Assignment Misalignments Dipoles:0.3 mm shift and 0.3 mrad angle for all axes Quadrupoles:0.2 mm shift and 0.3 mrad angle for all axes Field Errors Dipoles ΔBL/Bρ :0.5  10 -3 All errors are gaussian distributed with a cut-off at 3σ 26-Mar-092PS2 Orbit Correction - Update

3. Positions of Correctors and BPMs Horizontal corr. (black) Vertical corr. (red) BPMs for both planes at each corrector one vert. corrector removed in the centre 56 hor. and 54 vert. correctors; 110 BPMs 26-Mar-093PS2 Orbit Correction - Update

4. Sensitivity to different errors ErrorAver. maximum displacement in [mm] Hor.Vert. Relative dipole field error Δ BL/Bρ0.5  10 -3  TGAUSS(3)8.8- Transverse quadrupole shift DX, DY0.2 mm  TGAUSS(3)8.88.6 Longitudinal dipole shift DS0.3 mm  TGAUSS(3)0.3- Tilt of dipoles about s-axis DPSI0.3 mrad  TGAUSS(3)-5.4 Calculated with a sample of 50 machines; Q x = 13.25 Q y = 8.21 26-Mar-094PS2 Orbit Correction - Update

5. Results before/after correction Before correctionAfter correction HorizontalVerticalHorizontalVertical Average of max. displacement [mm] 13.5611.630.540.43 Average of r.m.s displacement [mm] 5.16 4.970.150.11 Calculated with a sample of 500 machines Q x = 13.25, Q y = 8.21 100 correctors (instead of 110) in use; failure of 5 % of the monitors Corrector kicks are below 1 mrad (maxima ~ 0.2 mrad) ρ = length/θ = 0.3/2e-4 = 1500 m B = (Bρ) extr /ρ = 170/1500 ≈ 0.12 T 26-Mar-095PS2 Orbit Correction - Update

6. Orbit before/after correction, hor. 500 machines 26-Mar-09PS2 Orbit Correction - Update6

7. Orbit before/after correction, vert. 500 machines 26-Mar-09PS2 Orbit Correction - Update7

8. Conclusion Orbit corrected by a factor of ≈ 25OK Failure of correctors and monitors no issue Maximum corrector strength ≈ 0.2 mrad gives B = 0.12 T for 0.3 m length 26-Mar-09PS2 Orbit Correction - Update8