| 摘要 |
PURPOSE:To enable the long-term observation of the behavior of a melt by X-rays by using a material having a large coefft. of X-ray absorption as a core, adjusting and forming a layer which is insert to the melt and has a high m.p. to the thickness at which the entire sp. gr. is equal to the sp. gr. of the melt and forming the outermost layer in such a manner that said layer is easily wettable with the melt. CONSTITUTION:The core 1 consists of the material such as tungsten, molybdenum or platinum having the high coefft. of X-ray absorption. The inside shell 2 is adjusted and coated of quartz glass, boron nitride, etc., to the thickness at which the density over the entire part of the tracer is nearly the same as the sp. gr. of molten silicon. Furthermore, the outermost circumferential shell 3 is coated with carbon powder, silicon nitride, etc., which are easily wettable with the melt. The long-term observation of the tracer corresponding to the convection of the melt by an X-ray radiographic method is thereby enabled when the silicon polycrystal in a quartz crystal is held at 1,500 deg.C in gaseous argon. |
