For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

For evaluating a polycrystalline silicon rod to be used as a raw material for production of FZ Si single crystals, novel evaluation values (values of characteristics×amount of crystals) including the amount of crystals grown in the growth direction (radial direction) are defined and the homogeneity in crystal characteristics in the growth direction (radial direction) is evaluated. Specifically, the homogeneity of the polycrystalline rod is evaluated by sampling a plurality of specimen plates each having, as a principal plane thereof, a cross-section perpendicular to a radial direction of the polycrystalline rod grown by a Siemens method at equal intervals in the radial direction, determining values of characteristics of the crystals of the specimen plates by measurements, and by using evaluation values obtained by multiplying amounts of the crystals (relative amounts of the crystals) at sites where the specimen plates have been sampled by the values of the crystal characteristics.

Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.

Provided is a method for producing a crystal fiber which can suppress the occurrence of stress birefringence even while distributing a light emission center so as to concentrate on a cross-sectional middle portion. The method for producing a crystal fiber comprises the steps of: using, as a preform, the crystal fiber comprising a light emission center that volatilizes from a melted portion upon the melting of a crystal, and heating a portion or a plurality of portions of the side of the preform, whereby the portion or the plurality of portions of the preform are melted such that only a given amount of the inside of the portion or the plurality of portions of the preform is not melted, to form the melted portion; and sequentially transferring the melted portion in the longitudinal direction of the preform, and cooling the melted portion, whereby the melted portion is continuously recrystallized to form a recrystallized region.

Provided is a method for producing a crystal fiber which can suppress the occurrence of stress birefringence even while distributing a light emission center so as to concentrate on a cross-sectional middle portion. The method for producing a crystal fiber comprises the steps of: using, as a preform, the crystal fiber comprising a light emission center that volatilizes from a melted portion upon the melting of a crystal, and heating a portion or a plurality of portions of the side of the preform, whereby the portion or the plurality of portions of the preform are melted such that only a given amount of the inside of the portion or the plurality of portions of the preform is not melted, to form the melted portion; and sequentially transferring the melted portion in the longitudinal direction of the preform, and cooling the melted portion, whereby the melted portion is continuously recrystallized to form a recrystallized region.

Provided is a method for producing a crystal fiber which can suppress the occurrence of stress birefringence even while distributing a light emission center so as to concentrate on a cross-sectional middle portion. The method for producing a crystal fiber comprises the steps of: using, as a preform, the crystal fiber comprising a light emission center that volatilizes from a melted portion upon the melting of a crystal, and heating a portion or a plurality of portions of the side of the preform, whereby the portion or the plurality of portions of the preform are melted such that only a given amount of the inside of the portion or the plurality of portions of the preform is not melted, to form the melted portion; and sequentially transferring the melted portion in the longitudinal direction of the preform, and cooling the melted portion, whereby the melted portion is continuously recrystallized to form a recrystallized region.

Provided is a method for producing a crystal fiber which can suppress the occurrence of stress birefringence even while distributing a light emission center so as to concentrate on a cross-sectional middle portion. The method for producing a crystal fiber comprises the steps of: using, as a preform, the crystal fiber comprising a light emission center that volatilizes from a melted portion upon the melting of a crystal, and heating a portion or a plurality of portions of the side of the preform, whereby the portion or the plurality of portions of the preform are melted such that only a given amount of the inside of the portion or the plurality of portions of the preform is not melted, to form the melted portion; and sequentially transferring the melted portion in the longitudinal direction of the preform, and cooling the melted portion, whereby the melted portion is continuously recrystallized to form a recrystallized region.

A method of method of forming or repairing a superalloy article having a columnar or equiaxed or directionally solidified or amorphous or single crystal microstructure includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array corresponding to a pattern of a layer of the article onto a powder bed of the superalloy to form a melt pool; and controlling a temperature gradient and a solidification velocity of the melt pool to form the columnar or single crystal microstructure.

A method of method of forming or repairing a superalloy article having a columnar or equiaxed or directionally solidified or amorphous or single crystal microstructure includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array corresponding to a pattern of a layer of the article onto a powder bed of the superalloy to form a melt pool; and controlling a temperature gradient and a solidification velocity of the melt pool to form the columnar or single crystal microstructure.

A single crystal production apparatus that is designed to produce a single crystal by cooling a melting zone formed by a heating part including an infrared generation part and a reflection part, wherein: the reflection part includes a spheroidal mirror and a concave spherical mirror; the infrared generation part is disposed at one focal point of the spheroidal mirror; an opening is formed in the spheroidal mirror on the side of the other focal point of the spheroidal mirror; and the one focal point and the spherical center of the concave spherical mirror fall on the same location.