Adjustable heat shield assembly

摘要

A novel apparatus is disclosed for use in controlling in a known and predictable manner the temperature of the top surface of a capillary die and the adjacent meniscus during the growth of a crystalline body. The novel apparatus comprises an adjustable heat shield assembly with relatively movable members which can be positioned in such a manner as to provide improved temperature control at the top end of the die which assists in ensuring that a crystalline body grown by means of the capillary die will have a substantially constant cross-sectional size.