CUSP ELECTROMAGNETIC FIELD DEVICE OF LARGE-DIAMETER SINGLE-CRYSTAL FURNACE

摘要

Disclosed is a cusp electromagnetic field device of a large-diameter single-crystal furnace. The device comprises direct current coils (2, 6) for generating a cusp electromagnetic field and at least two annular closed vessels filled with cooling oil. The two annular closed vessels are superposed up and down to form a hollow cylindrical shape. Each closed vessel is formed by welding half-enclosed shields (1, 7) located outside the vessel and an inner cylinder (12) and two baffle plates (11) located inside the vessel to each other. A pipeline, an oil pump, and an oil cooler (13) together form a forcible oil cooling system. A group of direct current coils (2, 6) formed through winding of solid copper pipes are disposed in each closed vessel. Since an upper coil and a lower coil are arranged in parallel, generated magnetic force lines are distributed in an axial symmetry manner, the magnetic field strength is continuously adjustable, axial and radial evenness of a crystal bar is ensured, and the effect of controlling the oxygen content of a single crystal is desirable. In usage, the dichotomous structure is linked through bolts, so that the transport, disassembly, assembly, and debugging are simpler and more convenient.