Technical Design Report Super Fragment Separator

DRAFT
mole (see also Figure 2.4.158 and Figure 2.4.160). The latter types are of cylindrical aperture and
thus the advantages of a rotating coil based method are evident. Considering the overall length of a
magnet mounted in its cryostat on a test bench, which will be in the order of about 6 m, the mole
based approach is favoured over the pure rotating coil approach here [108].
The mole will be placed sequentially at different lateral positions to cover the whole area, and the
field quality can be derived from these measurements [111].
Although search coils seem to be more appropriate for the rectangular apertures of SIS100 dipoles,
the use of the modular mole ready for testing the other superconducting magnets is preferred as it
can also measure the field direction of the main field and the higher order multipoles of the dipole.
Different lateral measurement will then need to be combined to a single set of harmonics [112,113].
A dedicated search coil will be used to cross-check the integral dipole strength measured by the
mole.
Figure 2.4.158: Sketch of the modular magnetic measurement system. This system is based on a "mole".
On top a measurement device as used for a standard measurement is shown. It consists of a driving unit, a
field probe, and a probe for searching the axis. The driving unit contains the motor, the angular encoder, and
the inclinometer. The field and axis probes contain the field and axis coils, respectively. On the right side the
glass window completes the device. In the mid of the coil a retro-reflector is mounted. The dynamic effects of
the field are measured ramp by ramp.
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