Abstract: While monitoring the phase state of a material in processes including crystallization from a melt, a photo-optical system is operated to receive the radiation coming from the material being treated, and the amplitude-frequency spectrum of the output electric signal of the photoreceiver of this system is followed. The presence in this signal of a low-frequency components within a range of from 0.5 to 30 Hz indicates that the optical system is located above the molten portion of the material being treated. To utilize this method for monitoring the position of the interface between the solid and molten zones or phases, there is employed a carriage supporting thereon the photo-optical system and mounted for reciprocation transversely of the interface between the liquid and solid phases. The output of the photoreceiver of the photo-optical system is provided with a frequency-amplitude analyzer including a circuit for inhibiting the permanent component.

Abstract: A device, comprising a chamber, a container and two coolers that are arranged on the boundaries of a melted zone of a metal or semiconductor being processed. Each cooler is sectionalized, with its heat-removing elements, adjoining the container, being insulated electrically with respect to the chamber and to each other and with each section being an electrically broken element. Arranged intermediate of the coolers is a high-frequency induction heater. Said container and the high-frequency heater are mounted movably relative to each other in a longitudinal direction.