380 Ë 10 HTS Maglev launch technology
Fig. 10.5:Profile of the magnetic field generated by the superconducting coil magnet whenIDC=40 A
measured atz=10 mm along thez-direction (a) and thex-direction [24] (b).
measured while the transport current varied at a constant rate. The ramping speeds
were−1.0,−2.0, 1.0, and 2.0 A/s. The inductance value obtained for each speed was
averaged. The center field along thez-axis of the coil was measured with a Hall probe
at various current values. The field constant was determined by taking the slope of the
center field versus the input current.
The coils were connected in series with subsequent opposite polarities making it
a four pole excitation system with a pole pitch of 126 mm (Fig. 10.7). The excitation
system was submerged in liquid nitrogen inside a homemade ‘cryostat’ made of
Styrofoam reinforced with a silicon based low-temperature adhesive.
The three-phase stator was made of conventional copper coils with a coil pitch
ofw=42 mm with iron teeth as its cores for the enhancement of the magnetic field
density along thez-axis,Bz. At 10 mm above the surface of the stator, alternating
current withIAC=8 A generatedBz=368 Gauss. All experiments discussed in this