October 27, 2020 - Wien magnetic field mapping and characterization meeting

Media:Magnetic field mapping meeting Oct 27 2020.pptx

Hardware:

 *   Use new SCE 20A/75V PS for measurements. This is the same type of PS that will be used for oparations
 *   DC power will install new SCE PS in magnet test ~10/29/20
 *   Software will provide EPICS controls and hysteresis ramp loops
 *   Label and wire coil leads to ensure positive current produces positive B field per convention
 *   Hysteresis limits: +/- 19.9A

Field mapping:

 *   Hall probe step size 2 mm
 *   On axis values z=[-25,25] cm
 *   Background: measure z=[-30,30] cm. First run the probe in this range w/o the magnet. Then place the magnet for measurements and do a full map at 0 A after hysteresis at 0A . Finally subtract from each value.
 *   Off axis values: limited by 15 mm diameter nickel endplates hole and 6 mm square hall probe. Measure z=[-25,25] cm once at 18A and as far as these limitations allow in +X,-X,+Y,-Y and record X,Y positions for comparing with models.
 *   Measure at +/-19.9A, +/- 15A, +/- 10A, +/-5A and 0A.

CED field map

 *   Measure B vs. I  at center of magnet using the EPICS hysteresis cycle at the beginning then top down through currents.  

Other measurements:

 *   V vs I resistance and inductance.