ELENA Electron Cooler Magnetic Measurements Measure field and

ELENA Electron Cooler Magnetic Measurements Measure field and adjust fine correctors to achieve B┴/Bǁ <5 x 10 -4 for central 65 cm

Method based on Magnetic Field Measurements in the Electron Cooling Device for LEAR 1 Allows for correction of probe-magnet misalignment and probe-hall plate misalignment 1. A. Wolf, L. Hütten and H Poth, Magnetic Field Measurements in the Electron Cooling Device for Lear

Mathematical correction to measurements for misalignment given by: β 1 and β 3 can be found through method a α 2 and α 3 can be found through method b

Other sources of error Transverse hall effect – sign does not change when magnetic field direction changed Probe arm sag – adjust probe arm angle and offset CMM position Probe dampening timescale – find through experimentation

Method -Align Solenoid axis to CMM arm -Align autocollimator to solenoid axis -Magnet conditioning -Power until thermal equilibrium is reached -Measure probe angles at start of line -Magnetic measurements along line -Measure probe angles at end of line

Initial coarse sweep of individual solenoids Choose best solenoid for the drift solenoid Coarse sweep of full assembly with nominal currents in corrector coils Adjust currents where necessary Detailed sweep of full assembly to confirm magnetic field homogeneity