IN5 with 10T

256CRHV41 (10T)

Stray Magnetic Field and Siting Issues on D3

We present below the magnetic forces measured on IN5 with the 10T symmetric split-pair coil magnet 256CRHV41. At the location of the last chopper, i.e. at 1.23 m from the sample axis, the magnitude of the stray field is about 185 Gauss. This leads to some magnetic forces and substantial eddy currents warming up the chooper discs. A magnetic shielding has therefore been installed inside the chopper casing to reduce the chopper discs warming issue.

With the magnetic shield, the chopper discs temperature raises by 5°C at nominal field while magnetic forces remain acceptable. In these conditions, the operation of this 10T magnet on IN5 is safe.