Magnet Measurement Plan APS MBA M1 R&D Magnet Joe DiMarco, et al. 26 November 2013

Measurement Goals Validate the magnetic model Characterize the magnet for use in lattice modeling Guide magnet design modifications to improve the magnet model and lattice performance

Measurement plan Initial Thoughts Thermal behavior of the magnet at full excitation. ∫B × dl through the entire magnet as a function of x and at various currents. B(x=0,s) through the entire magnet (including end fields). B(x,z) through the entire magnet (including end fields). B(I). Fringe field outside the core in any locations agreed upon. Possibly harmonic coefficients of the integrated over a short distance in z at multiple z positions.

Thermal measurements Measure vs. time until stable, perhaps at multiple currents Thermocouples attached to magnet core and coil at strategic points Inlet and outlet water temperatures Voltage and current → resistance → average coil temperature Air temperature Water flow

Single-wire Stretched Wire ∫B × dl straight through the entire magnet Not exactly numbers desired for lattice, but can be compared to magnetic model Absolute integrated strength at multiple currents Integrated strength vs. x and y Move wire in circle to get integrated harmonics

Hall Probe on Beam Orbit Pull Hall probe down length of magnet in channel tailored to beam orbit

Hall Probe Array Array (in x ) of Hall probes inserted from side Move down length of magnet mapping field in rectilinear x and z grid Interpolate to get field on orbit and perpendicular to orbit

Hall Probe Excitation curve Detailed B(I) at a few appropriate points

Fringe Fields Hall probe scans will include end fields out to arbitrary distances Can measure leakage fields in any other directions desired with hand-held Hall probes

Rotating Coil Short rotating radial printed circuit board coil (“ferret”) Insert from side at multiple z locations Detailed harmonic decomposition of field Would be possible, but requires more development than other measurements