Abstract: Provided are a crucible which prevents polycrystal formation to easily allow growth of optical part material single crystals, and a single crystal growth method employing the crucible. The crucible has a smooth surface of about Rmax 3.2 s as the surface roughness of the wall surface 1H, concave curved plane 1J, cone surface 1F and convex curved plane 1L of the starting material carrying section 1D and the wall surface 1K of the seed carrying section 1E, which constitute the inner surface of the crucible of a crucible body 1A.

Abstract: Provided are a crucible which prevents polycrystal formation to easily allow growth of optical part material single crystals, and a single crystal growth method employing the crucible. The crucible has a smooth surface of about Rmax 3.2 s as the surface roughness of the wall surface 1H, concave curved plane 1J, cone surface 1F and convex curved plane 1L of the starting material carrying section 1D and the wall surface 1K of the seed carrying section 1E, which constitute the inner surface of the crucible of a crucible body 1A.

Abstract: Provided are a crucible which prevents polycrystal formation to easily allow growth of optical part material single crystals, and a single crystal growth method employing the crucible. The crucible has a smooth surface of about Rmax 3.2s as the surface roughness of the wall surface 1H, concave curved plane 1J, cone surface 1F and convex curved plane 1L of the starting material carrying section 1D and the wall surface 1K of the seed carrying section 1E, which constitute the inner surface of the crucible of a crucible body 1A.

Abstract: The present invention provides an inorganic scintillator including a matrix material comprising a metal oxide, and a luminescence center made of Ce contained in the matrix material, the inorganic scintillator being adapted to scintillate in response to a radiation; wherein the matrix material further comprises a dopant having a tetravalent ionization energy I [kJ·mol?1] satisfying the condition represented by the following expression (1): 3000?I?3500.

Abstract: Provided are a crucible which prevents polycrystal formation to easily allow growth of optical part material single crystals, and a single crystal growth method employing the crucible. The crucible has a smooth surface of about Rmax 3.2s as the surface roughness of the wall surface 1H, concave curved plane 1J, cone surface 1F and convex curved plane 1L of the starting material carrying section 1D and the wall surface 1K of the seed carrying section 1E, which constitute the inner surface of the crucible of a crucible body 1A.

Abstract: The present invention provides an inorganic scintillator including a matrix material comprising a metal oxide, and a luminescence center made of Ce contained in the matrix material, the inorganic scintillator being adapted to scintillate in response to a radiation; wherein the matrix material further comprises a dopant having a tetravalent ionization energy I [kJ·mol?1] satisfying the condition represented by the following expression (1): 3000?I?3500 ??(1)

Abstract: A single crystal of a silicate of a rare earth element herein provided is characterized in that it has a Ce concentration of not less than 0.6 mole % and not more than 5 mole % and that it has a light transmittance, as determined at a wavelength of 450 nm, of not less than 75%. The single crystal permits the solution of the problems associated with the conventional techniques or the problems concerning the coloration of the resulting single crystal and the reduction of the light transmittance thereof, which are disadvantages observed when the Ce concentration of the single crystal is increased to reduce the fluorescence-attenuation time. The single crystal thus permits the high-speed diagnosis of PET devices.

Abstract: A single crystal of a silicate of a rare earth element herein provided is characterized in that it has a Ce concentration of not less than 0.6 mole % and not more than 5 mole % and that it has a light transmittance, as determined at a wavelength of 450 nm, of not less than 75%. The single crystal permits the solution of the problems associated with the conventional techniques or the problems concerning the coloration of the resulting single crystal and the reduction of the light transmittance thereof, which are disadvantages observed when the Ce concentration of the single crystal is increased to reduce the fluorescence-attenuation time. The single crystal thus permits the high-speed diagnosis of PET devices.

Abstract: To provide a neutron scintillator, which does not contain a heavy element, which is absolutely necessary in realizing a scintillation detector having low sensitivity to gamma ray and fully capable of counting high intensity neutron, Cu is doped in oxide comprised of Li and B. The oxide comprised of Li and B is a transparent single crystal having composition ratio of Li2B4O7. The neutron scintillator contains Cu by 0.001 to 0.1 wt %. Furthermore, a (001) plane cut off perpendicularly to a growth axis and polished from the single crystal whose orientation has been grown in a <001> axis is made to be a scintillator plate crystal.