Technical Design Report Super Fragment Separator

DRAFT
2.4.2.3.1 Radiation resistant hexapole magnets
It is planned to be built the radiation resistant hexapole magnets as normal conducting magnets
using MIC cables, like for the radiation resistant dipole and quadrupole magnets. Two of such
hexapole magnets are required, one before the first dipole unit and one behind the third dipole,
close to the first focal plane PF1. The hexapole magnets have a pole tip radius of 200 mm (useful
aperture is 190 mm) achieving a hexapole component of 34 T/m 2 .
Design of the sextupole magnet
Figure 2.4.55 shows a 3D view of the radiation resistant hexapole. The iron yoke is divided into six
parts, fixed together with bolts and dowels. Each part of the iron yoke consists of separate lamellae
with radiation-resistant insulation on their surfaces. The lamellae are welded together over the
external surface of the hexapole magnet and special studs and hooks additionally tighten them
together in the pole area. Thus the magnetic field in the hexapole magnet does not pass through
close circuits in the iron yoke.
The diameter of the circle inscribed between the magnet poles should be observed with accuracy
better than ±100µ. The distances between neighboring poles should be observed with accuracy
better than ±50µ.
It is planned to equip the hexapole magnet with two water feeding and collectors, allowing separate
supply of water to each current coil cooling pipe (see Figure 2.4.56). The coils are electrically
connected in series so that assembling or dismantling two halves of the hexapole magnet it will be
sufficient dismantle only one connection of the copper bus-bar (see Figure 2.4.55).
Figure 2.4.55: 3D view of the radiation resistant hexapole magnet. Electric circuit (right side) and water
cooling circuit (left side) are separated from each other.
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