  Thrust measurements were performed on a coil made of YBa2Cu3O7-d coated
conductor acting as the excitation system of a single-sided linear synchronous
motor. The superconducting coil was a single pancake in the shape of a
racetrack with 100 turns, the width and effective lengths were 42 mm and 84 mm,
respectively. The stator was made of conventional copper wire. At 77 K and a
gap of 10 mm, with an operating direct current of I_DC=30 A for the
superconducting coil and alternating current of I_AC=9 A for the stator coils,
thrust of 24 N was achieved. With addition of an iron core, thrust was
increased by 49%. With addition of an iron back plate, thrust was increased by
70%.
