Experiments with Supersonic Beams as a Source of Cold Atoms

Figure 4.20: An exploded view of the 64 stage coilgun coil. Each Permendur disc is
3 mm thick, and 10.2 mm in diameter. The wire is wound around the 3 mm O.D.
center Vespel cylinder. Figure Courtesy Christian Parthey.
4.5.1 64 Stage Coil Design
The design of the coils used in the 64 stage coilgun is slightly modified from
those used in the proof-of-principle experiment and described in section 4.4.2. The
main change is that rather than using a magnetic steel cup, with one Permendur end
cap slightly thinner than the other, the end caps are made with the same thickness,
and the magnetic steel shell is now a cylinder.
The full specifications for the new coil are as follows. The coil consists of
5 × 6 windings of 500 μm diameter kapton insulated copper wire wound around a
3 mm bore. The coil is wound around a Vespel cylinder, which has a wall thickness
of 50 μm and an outer diameter of 3 mm. Each solenoid is sandwiched between two
Permendur discs with 10.2 mm diameter and 3 mm thickness. 150 μm thick Kapton
washers are placed between the wire and the permendur discs to protect the coils
and to keep the insulation from scratching during the winding process. The coils are
surrounded by a magnetic steel cylinder which is 9.6 mm long, with a 10.2 mm inner
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