A crucible assembly for growing a crystal ingot using a Czochralski process includes an outer crucible and an inner crucible. The inner crucible is disposed within the outer crucible and has a channel configured for fluid communication between the outer crucible and the inner crucible. The inner crucible is an arc-fused crucible and the outer crucible is a cast crucible.

One aspect relates to a process for the preparation of a quartz glass grain, including providing a silicon dioxide granulate from a pyrogenically produced silicon dioxide powder, making a glass melt out of silicon dioxide granulate, making a quartz glass body out of at least part of the glass melt and reducing the size of the quartz glass body to obtain the quartz glass grain. One aspect further relates to a quartz glass grain which is obtainable by this process. One aspect further relates to opaque quartz glass bodies, which are obtainable by further processing of the quartz glass grain.

A quartz glass crucible includes a crucible base body having silica glass and a coating film containing a crystallization accelerator and formed on the inner surface of the crucible base body. The coating film has a peel strength of 0.3 kN/m or more.

An apparatus for manufacturing a silica glass crucible includes a rotating means for rotating a mold and a supply means for feeding a silica powder inside the mold, wherein the supply means has a feeding part for delivering the silica powder in a manner releasing it to fall to a position away from the inner wall surface of the mold inside the mold, and a dispersing part for changing, to one toward the inner wall surface side, at a fall position, the direction in which the silica powder fed from the feeding part moves, while also widening an angle at which the silica powder disperses toward the inner wall surface at the fall position. The apparatus is intended to allow a silica powder layer to be stably formed in the mold in a short period of time.

A quartz glass crucible 1 having a cylindrical side wall portion 10a, a bottom portion 10b, and a corner portion 10c connecting the side wall portion 10a and the bottom portion 10b to each other includes a transparent layer 11 made of quartz glass, and a bubble layer 12 made of quartz glass and formed outside the transparent layer 11. A ratio of an infrared transmittance of the corner portion 10c at a maximum thickness position of the corner portion 10c to an infrared transmittance of the side wall portion 10a is 0.3 or more and 0.99 or less, and an absolute value of a rate of change in infrared transmittance in a height direction along a wall surface of the crucible from a center of the bottom portion 10b toward an upper end of the side wall portion 10a is 3%/cm or less.

Common solar radiation receivers are equipped with a chamber for transmission of an operating gas which is directed along to an absorber for solar radiation for thermal absorption. The absorber has a dome-shaped entry window made of quartz glass, wherein the inner side facing the absorber assumes a nominal interior temperature Ti of at least 950 C. during proper use, preferably at least 1000 C., whereas the outer side facing away from the absorber is exposed to the environment and subject to risk of devitrification. The invention relates to modifying the known solar radiation receiver so that a high absorber temperature can be set and thus a high efficiency of the solar thermal heating is enabled, without increasing the risk of devitrification in the region of the outer side of the entry window.

A destructive inspection method of a vitreous silica crucible for pulling a silicon single crystal evaluates a crack state of an inner surface of the vitreous silica crucible supported by a graphite susceptor when a load is instantaneously applied to at least one point on the inner surface via an automatic center punch while pushing the tip portion of the automatic center punch against the inner surface. The destructive inspection method can inspect the vitreous silica crucible under conditions as close to the actual conditions of use as possible.

A vitreous silica crucible includes: a substantially cylindrical straight body portion having an opening on a top end and extending in a vertical direction; a curved bottom portion; and a corner portion connecting the straight body portion with the bottom portion and a curvature of which is greater than that of the bottom portion, wherein an inner surface of the crucible has a concavo-convex structure in which groove-shaped valleys are interposed between ridges, and an average interval of the ridges is 5-100 m.

In an embodiment, a vitreous silica crucible 1 includes a cylindrical straight body portion 10a, a corner portion 10c formed at lower end of the straight body portion 10a, and a bottom portion 10b connected with the straight body portion 10a via the corner portion 10c. Moreover, the vitreous silica crucible 1 includes a bubble-containing opaque layer 11 constituting an outer layer, and a bubble-free transparent layer 12 constituting an inner layer. A boundary surface, between the opaque layer 11 and the transparent layer 12 in at least the straight body portion 10a, forms a periodic wave surface in a vertical direction. The vitreous silica crucible can suppress deformation under high temperature.

An apparatus for supporting setting of a manufacturing condition of a vitreous silica crucible includes: an improved property parameter setting unit configured to, if the degree of matching between three-dimensional shapes of simulation data obtained based on an initial property parameter and measurement data falls below a predetermined level, set an improved property parameter such that the degree of matching becomes higher than or equal to the predetermined level, and an improved manufacturing condition data setting unit configured to set a manufacturing condition such that simulation data matching the design data to a degree higher than or equal to a predetermined level is obtained. By using the apparatus, it is possible to manufacture a vitreous silica crucible by rotational molding in such a manner that the three-dimensional shape thereof matches the design data to a high degree.