Disclosed are a yttrium-doped barium fluoride crystal and a preparation method and the use thereof, wherein the yttrium-doped barium fluoride crystal has a chemical composition of Ba.sub.(1−x)Y.sub.xF.sub.2+x, in which 0.01≤x≤0.50. The yttrium-doped BaF.sub.2 crystal of the present invention has improved scintillation performance. The yttrium doping may greatly suppress the slow luminescence component of the BaF.sub.2 crystal and has an excellent fast/slow scintillation component ratio. The doped crystal is coupled to an optical detector to obtain a scintillation probe which is applicable to the fields of high time resolved measurement radiation such as high-energy physics, nuclear physics, ultrafast imaging and nuclear medicine imaging.

An ingot includes a first surface, a second surface opposite to the first surface, and a third surface positioned along a first direction and connecting the first surface and the second surface. The ingot includes: a first pseudo single crystal region; an intermediate region containing one or more pseudo single crystal regions; and a second pseudo single crystal region. The first pseudo single crystal region, the intermediate region, and the second pseudo single crystal region are positioned adjacent sequentially in a second direction perpendicular to the first direction. In the second direction, a width of each of the first and second pseudo single crystal regions is larger than a width of the first intermediate region. Each of a boundary between the first pseudo single crystal region and the intermediate region and a boundary between the second pseudo single crystal region and the intermediate region includes a coincidence boundary.

A polycrystalline silicon wafer is provided. The polycrystalline silicon wafer, includes a plurality of silicon grains, wherein the carbon content of the polycrystalline silicon wafer is greater than 4 ppma, and the resistivity of the polycrystalline silicon wafer is greater than or equal to 1.55 -cm.

A polycrystalline silicon wafer is provided. The polycrystalline silicon wafer, includes a plurality of silicon grains, wherein the carbon content of the polycrystalline silicon wafer is greater than 4 ppma, and the resistivity of the polycrystalline silicon wafer is greater than or equal to 1.55 -cm.

A method of making a component includes: depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.

A method of making a component includes: depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.

Disclosed are a yttrium-doped barium fluoride crystal and a preparation method and the use thereof, wherein the yttrium-doped barium fluoride crystal has a chemical composition of Ba.sub.(1x)Y.sub.xF.sub.2+x, in which 0.01x0.50. The yttrium-doped BaF.sub.2 crystal of the present invention has improved scintillation performance. The yttrium doping may greatly suppress the slow luminescence component of the BaF.sub.2 crystal and has an excellent fast/slow scintillation component ratio. The doped crystal is coupled to an optical detector to obtain a scintillation probe which is applicable to the fields of high time resolved measurement radiation such as high-energy physics, nuclear physics, ultrafast imaging and nuclear medicine imaging.

Disclosed are a yttrium-doped barium fluoride crystal and a preparation method and the use thereof, wherein the yttrium-doped barium fluoride crystal has a chemical composition of Ba.sub.(1x)Y.sub.xF.sub.2+x, in which 0.01x0.50. The yttrium-doped BaF.sub.2 crystal of the present invention has improved scintillation performance. The yttrium doping may greatly suppress the slow luminescence component of the BaF.sub.2 crystal and has an excellent fast/slow scintillation component ratio. The doped crystal is coupled to an optical detector to obtain a scintillation probe which is applicable to the fields of high time resolved measurement radiation such as high-energy physics, nuclear physics, ultrafast imaging and nuclear medicine imaging.

A method of making a component includes depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.

A method of making a component includes depositing a metallic powder on a workplane; directing a beam from a directed energy source to fuse the powder in a pattern corresponding to a cross-sectional layer of the component; repeating in a cycle the steps of depositing and fusing to build up the component in a layer-by layer fashion; and during the cycle of depositing and melting, using an external heat control apparatus separate from the directed energy source to maintain a predetermined temperature profile of the component, such that the resulting component has a directionally-solidified or single-crystal microstructure.