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AC/GEO mole measurements Based on outcome from meeting 24/11 2005 and Installation data

AC/GEO mole measurements Based on outcome from meeting 24/11 2005 and Installation data. Elena Wildner J. Beauquis, L. Bottura, M. Buzio, D. Missiaen, P. Winkes. Background.

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AC/GEO mole measurements Based on outcome from meeting 24/11 2005 and Installation data

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  1. AC/GEO mole measurementsBased on outcome from meeting 24/11 2005 and Installation data Elena Wildner J. Beauquis, L. Bottura, M. Buzio, D. Missiaen, P. Winkes Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  2. Background There was a systematic difference of the data for the two measurement moles (AC from AT/MTM and GEO from TS/SU) for the geometric axis of the SSS of ~ 0.25 mm in the vertical plane, integrated over all measurement points for magnets 177, 154, 249, 349, 49 SSS 14, 50, 74, 160, 162, 174 and 180 (0.2-0.3 mm) have a similar problem The observed systematic difference depends on the mole pair used For magnets 49, 249 and 349 the AC mole was used for the install pack For magnets 177 and 152 the GEO mole was used in the absence of the AC mole. This triggered an investigation of the calibrations Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  3. List of Actions made Calibrations of the moles used for the batch (AC4, GEO13) The GEO mole 13 was found to have an offset of -0.12 mm. The GEO mole has been repaired, not necessarily drift, uncontrollable mechanical effect The AC mole has been re-calibrated the calibration difference was 0.09 mm. Cross calibration is going on between the two mole: Results are not yet conclusive. Measurement conditions need to be better controlled. A better test bench will be set up The center of a calibrated tube will be measured in the metrology lab (3D measurements, 20m precision), the AC-mole and the GEO-mole will be used to measure the center Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  4. Calibrations checks, Future I The operator software will be changed. A warning will be given if the integrated (over the SSS) difference of the two mole is > 0.2 mm. In this case both moles will be changed and the magnet re-measured. The old moles will go for calibration and maintenance. May be iterated. Concerns 10% of the measurements. The AC mole will always be the reference for the GAif the AC mole data is correctly measured. To calculate GA with AC mole was originally decided due to the fact that only one measurement made for both magnetic and geometric axes. The geo-mole is there to cross check. The GEO mole is used to check that the AC mole is not completely out which happens from time to time. Extensive efforts have been made to certify the AC-mole: AC mole 6 is used in the reference: Magnetic and mechanical axis of Short Straight Sections in the arcs: a summary of the results of the first 111 warm and cold series tests. L.Bottura et al. Note 373 The magnet will always be measured using both moles.Both measurements will be given in the shift tool. In addition: weekly calibrations and checks of both moles will be made, and tracked in the data base. A common calibration bench will be set up. Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  5. Other checks, saw tooth For the SSS, there are no important saw tooth phenomena. This is only a problem for dipoles. The saw tooth will be checked. The distance to the Leica will be taken into account in the plots (only information, no recalculations). TS/SU will check the influence on the GA-calculation of weighing of the measurement points. From this a decision will be taken. If the saw tooth is constant over the measurement, re-calibration or re-measurement may be required. I don’t agree with this. It can also be a problem of relocation of the station 2 wrt to station 1 Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  6. Statistics, difference GEO-AC, point by point/integrated Statistics, difference GEO-AC, point by point 3 sigma tail: 37 points h, 39 points v Statistics, difference GEO-AC, integrated 3 sigma tail: no points Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  7. Statistics, histogram for individual points, interpolated Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  8. Statistics of difference GEO-AC Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  9. Statistics of difference GEO-AC, zoom and details AC #3 GEO #3 AC #6 GEO #3 AC #6 GEO #13 AC #4 GEO #13 Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  10. SSS 49 and 349 After correction by Patrick Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  11. Recent measurements, not corrected Difference of AC and GEO: mean for mole combination H V H V Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  12. Conclusions for the batch Estimated accuracy 0.2 mm.For the batch from MEB 102:For magnet 49, 349: use existing AC mole data with the calibration of offset of -0.09 mm.Magnet 152, 177 and 249 will be re-measured, no AC mole data available for 152 and 177, 249 will be re-checked and scanned atthe ends, to see which mole is closest to flange. Only one magnet has to be remeasured, conclusion drawned and decision taken if we have to remeasure the others Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  13. Suggestions for calibrations and checks The calibrations and maintenance of the moles have to be followed up for all moles used, for all magnets, also in industry To keep an overall track of this in the data base is offeredWe have to estimate how the offsets in calibration and saw tooth influence the statistics for correctors, due to shift in GA and also classification at WP08 (dipole). Development of a “derived data” package for SSS as for the dipole will be made to estimate important quality criteria.Magnetic mole calibrations to be revisited as wellCheck impact of flange positions for SSS Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  14. Installation info (I) There are no predefined install packs in the data base for the SSS. The slot showing the choice for GA calculation is used as install pack. No other install pack is possible unless a new reference measurement is chosen and a new GA is calculated for all valid measurements. This must remain an exception since the reference measurement is chosen by measurement specialists. If several measurements from the same measurement device are available in the database (re-measurements), only one is valid. The others are not accessible (only specialists can access). We will add a slot “install pack” for the SSS. When this slot is filled it will be checked that the install pack chosen by ABP is the same as the measurement used for GA calculation. If this is not the case the filling of shifts and install pack will not be possible. This is to check that no ambiguity exists for validating the shift. Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  15. Installation info (II) A list of installation data from the installation data base ( views asked from EDMS team) and the MAS data base will be produced to show slots and magnets with the shift data and fiducials will be produced (web based). For the Dipole, the default for install pack (last measurement) that was implemented according to demands by AB/ABP, will be obsolete. Only one set of fiducial data available for a valid measurement set (mag, mech, fid, SSW) Only once all calculations are made and all measurements are expressed in the same reference system, the certification can be made by looking at all measurements together (MAS). We can add both measurements, AC and GEO, in the shift tool if wanted. Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

  16. Installation info overview web page Measurements and DB meeting 1 December, 2005, Elena Wildner AT/MAS

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