Magnetic Measurements and Alignment Issues

1. Magnetic Measurements and Alignment Issues Robert Ruland, SLAC

2. Undulator Alignment Process • Optical Alignment requires direct line of sight between instrument and target  fiducials need to be either on aisle side or on top of component Robert Ruland, SLAC

3. Alignment Operation and Tolerances (PM Quads) • Quadrupole alignment • Quadrupoles too small to carry fiducials • is accomplished by relative alignment to adjacent undulator • Carried out in MMF using CMM, no optical alignment involved • undulator wrt to BBA-aligned quadrupoles relative alignment requirements: 70 µm in Y, 300 µm in X • Using the undulator fiducials to align quadrupoles: fiducialization quadrupole axis to quadrupole fiducials to undulator fiducials X, Y 30 µm • Undulator • Cradle, quadrupole, BPM are aligned wrt undulator fiducials • Carried out by optical alignment, supported by HLS and portable stretched wire measurements • Quadrupole ab-initio position tolerance driven by BBA requirements; BBA quality is correlated to quality of initial alignment – mover motion range is about 3-times StD of alignment  BBA residual offsets are among others a function of quality of initial alignment • Alignment StD of 150 µm sufficient for BBA to converge, goal is alignment StD of < < 100 µm Robert Ruland, SLAC

4. Alignment Fiducials and Abbe’s Law • Abbe’s Law postulates that in order to avoid 1st order errors, the measurement needs to take place in the principle plane of the dimension • Hence: Horizontal measurement wrt fiducial in horizontal plane Vertical measurement wrt fiducial in vertical Robert Ruland, SLAC

5. Effect of violating Abbe’s Law (1) • Already placing the top fiducial not exactly in vertical plane of rotation creates too much of a roll correlation, assuming 1 mrad roll • Need to change fiducial position into plane of rotation, or need to control roll about 0.1 mrad Robert Ruland, SLAC

6. Roll Tolerance presently defined = 1mrad To reduce roll correlation to become insignificant, tolerance needs to be 0.1 mrad This requires to set elevation of both fiducials to better than 10 µm  cannot be done with optical measurements Effect of violating Abbe’s Law (2) Robert Ruland, SLAC

7. “Gap open to Aisle” Fiducial Design • Gap open to aisle requires two fiducials per cross-section on top of undulator • Additionally, two reference surfaces to set roll using machinist level, one near either end • Do we need roll reference in any case, e.g. is present roll tolerance consistent with vacuum chamber stay clear? Robert Ruland, SLAC

8. MMF Lay-out Robert Ruland, SLAC

9. New MMF lay-out Modified Lay-out Highlights • Separation of magnetic measurements operation from fiducialization and assembly • Allows different temperature zones: mag.meas +/-0.1degC CMM / assembly +/- 1 degC Loading / Storage +/- 2.5degC • Assembly line type lay-out • Storage capacity for most (all) undulator segments Robert Ruland, SLAC

10. Installation Schedule Robert Ruland, SLAC

11. Installation and Alignment Schedule: Assumptions • Goal: Get ready for commissioning in July / August 2007 • SPEAR3 approach, complete as much work as possible before installation during pre-assembly • Aggressive concurrent scheduling • Optimize time not man-power • Only one shift work Robert Ruland, SLAC

12. Pre-assembly of installation units • Pre-assembled granite tables and cradles • Pre-assembly of granite tables • Mount support feet • Mount support table and mechanical adjustment system • Mount cam movers • Install temperature acquisition system • Install temperature insulation • Complete cabling, plug-in ready • Pre-align table supports and undulator supports • Pre-assembly of cradles • Attach cam mover kinematics • Install roll-away rails (& mover system) • Install undulator, quadrupole and BPM • Install vacuum system • Complete cabling, plug-in ready • Fiducialize and align Robert Ruland, SLAC

13. Alignment Scheme • All components use registration keys to preserve pre-alignment • Install and measure alignment network • Install floor anchors and foot plates • Align foot plates to better than 0.5 mm • Install granite tables onto foot plates • Re-measure alignment network • Align undulator mechanical supports • Install cradles • Install HLS and WPM • Re-measure alignment network • Align undulators Robert Ruland, SLAC

14. Installation and Alignment Schedule (Version 0.1) Robert Ruland, SLAC

15. Integration Robert Ruland, SLAC

16. Integrating Monitoring Systems into Cradle / Support System Since the cradle needs to be easily removable, we cannot attach the monitoring systems to it. Hence, both WPM and HLS need to be mounted to support table. However, the mounting has to be accomplish in a way which will force the sensors to follow the cradle motion Robert Ruland, SLAC

17. Integrating Monitoring Systems into Cradle / Support System Robert Ruland, SLAC

18. HLS Stability and Resolution Robert Ruland, SLAC

19. Integrating Monitoring Systems into Cradle / Support System Robert Ruland, SLAC

20. WPM Stability and Resolution Robert Ruland, SLAC