Undulator Tuning Status Z. Wolf, S. Anderson, R. Colon, S. Jansson, D. Jensen, S. Kaplunenko, Y. Levashov, Ed. Reese, A. Weidemann

Undulator Tuning Status Overview Status/Schedule Reference Undulator Undulator Repairs Radiation Damage

Re-Tuning We are re-tuning all the undulators because of damage from temperature excursions beam pipe interferences

Re-Tuning Schedule 25 undulators are in the tunnel 8 undulators are still required 2 undulators need repair 6 spares need to be tuned K vs Temperature studies still need to be done

Reference Undulator X-Trajectory, Y-Trajectory, Phase vs Z, measured many times X-Trajectory, Y-Trajectory, Phase vs Z, Phase In Cell, all stable

Field integrals stable, Reference Undulator I1XvsX I1YvsX Field Integral Measurements, Long Coil Reference Undulator never tuned for ±6 mm good field region I2XvsX I2YvsX Field integrals stable, but some systematic changes

Reference Undulator Started straightening coil routinely, improved I1X vs Time I1Y vs Time Field integral changes possibly due to coil straightness Field integrals at X=0 at different times I2X vs Time I2Y vs Time Started straightening coil routinely, improved repeatability

Reference Undulator Beam Axis Position The beam axis position relative to the tooling balls is affected by many errors. The repeatability of the reference undulator beam axis position is a measure of the rms error on K for the undulators in the tunnel.

Undulator Tooling Balls Relative To Beam Axis Reference Undulator Undulator Tooling Balls Relative To Beam Axis

Change In Beam X Position Relative To X Tooling Balls Reference Undulator Change In Beam X Position Relative To X Tooling Balls Average change doesn’t affect performance. RMS change is important.

Change In Beam Y Position Relative To Y Tooling Balls Reference Undulator Change In Beam Y Position Relative To Y Tooling Balls

MMF Temperature History Reference Undulator MMF Temperature History Aside: The 9 degree temperature excursion in December 2008 caused a one month delay while we recalibrated, straightened the bench, and checked all the undulators in the MMF. The smaller temperature excursions caused a one week delay each while we checked our calibrations.

MMF Temperature Excursions T > 22 C Reference Undulator MMF Temperature Excursions T > 22 C The large temperature excursions are not responsible for the slope in the beam axis x-position plot. deg C

Hall Probe Calibrations Reference Undulator Hall Probe Calibrations The hall probe was calibrated several times during the tuning. The changes in x-position remained. Hall probe calibration errors do not appear to be responsible for the change in beam axis x-position.

MMF Temperature Accuracy Reference Undulator MMF Temperature Accuracy T# Read Refere Differ 1 19.96 19.958 0.002 2 19.97 19.966 0.004 3 19.96 19.956 0.004 4 19.94 19.943 -0.003 5 19.93 19.931 -0.001 6 19.88 19.875 0.005 Yurii compared our temperature measurement system output to a reference thermometer on 4/16/09. The temperature difference is shown. We have done similar tests in the past, with similar results. There does not appear to be any significant error in our temperature measurements. deg C

Kugler Bench Reference Dipole Reference Undulator Kugler Bench Reference Dipole Reference Dipole, uniform field, NMR measurements (Bhall – Bnmr) / Bnmr is stable to better than 10-4 over the past year.

Hall Probe Calibration History Reference Undulator Hall Probe Calibration History a) c) Bcalib – Bnom vs Vhall Bnom is linear in V. (Take out linear part of calibration.) See some changes in probe. At V = 5 V (1 T), change in calibration over time. See an ageing of probe. Calibration takes this out. Residuals Bmeas – Bfit Residuals less than 0.2 G. b)

SN16 Radiation Damage Test Heinz-Dieter will comment on the dose and the number of equivalent years of usage.

Straightness Repairs Are Complete Undulator Repairs Straightness Repairs Are Complete 6 Undulators Before After

Undulator Repairs SN6 needs the end pole assemblies re-installed. SN4 needs a pole repaired. We are setting up a lab to do this work. In addition, we will install a block magnetizer and a helmholtz coil in this lab to repair undulators and allow prototype development.

Conclusion 25 undulators are in the tunnel 33 undulators will be installed in June Reference undulator trajectories and phases are stable Reference undulator axis position indicates rms ∆K/K errors of 3×10-5 for production 2 MMF temperature measurements appear accurate by comparing to a reference thermometer Reference dipole measurements are stable to 10-4 determined by comparing the hall probe to an NMR. Hall probe calibration fits have residuals less than 0.2 G. The hall probe shows some ageing with time. (The calibrations correct this.) A radiation damage test was done and no damage was detected. The final undulator repairs are in progress. Studies of K vs temperature will start as soon as the production work is done. We need to tune 6 spare undulators and then we are ready for routine radiation damage checks. We will be able to fix undulators and build small prototypes with our fixturing and block magnetizer.