| 摘要 |
<p>Magnetic field generating apparatus comprises a pair of axially spaced coils (10, 11) which are so arranged that when energised, they produce a magnetic field which has a zero axial field or substantially zero axial field at an axial position midway between the coils. The annular space between the coils is filled with a material (14) such as steel or steel with a layer of material magnetised in the radial direction, which enhances the radial field strength generated by the coils. The apparatus has application in the growth of single crystals of semiconductor material. <IMAGE></p> |
