The present invention provides a crystal of a europium compound containing europium. The present invention enables the preparation of a crystal of a europium compound having a powder X-ray diffraction pattern having a first diffraction peak in diffraction angle (2θ) range of 34.3° to 36.1° in which a half width of the first diffraction peak is 1.8° or less, and/or having a second diffraction peak in diffraction angle (2θ) range of 28.6° to 29.6° and a third diffraction peak in diffraction angle (2θ) range of 36.8° to 38.4° in which a half width of the second diffraction peak is 1.0° or less and a half width of the third diffraction peak is 1.6° or less, and being at least one compound selected from compounds represented by formulae (1) to (4):

EuCl.sub.x  (1)

Eu(OH).sub.2  (2)

Eu(OH).sub.2Cl  (3)

EuOCl  (4) x is 0.05 or more and 5 or less.

A scintillator, a preparation method therefor, and an application thereof are disclosed wherein the scintillator has a chemical formula of Tl.sub.aA.sub.bB.sub.c:yCe, wherein: A is at least one rare earth element selected from trivalent rare earth elements; B is at least one halogen element selected from halogen elements; a=1, b=2 and c=7, a=2, b=1 and c=5, or a=3, b=1 and c=6; and y is greater than or equal to 0 and less than or equal to 0.5. According to another embodiment, the scintillator has a chemical formula of Tl.sub.aA.sub.bB.sub.c:yEu, wherein: A is an alkaline earth metal element; B is a halogen element; a=1, b=2 and c=5, or a=1, b=1 and c=3; and y is greater than or equal to 0 mol % and less than or equal to 50 mol %.

A scintillator, a preparation method therefor, and an application thereof are disclosed wherein the scintillator has a chemical formula of Tl.sub.aA.sub.bB.sub.c:yCe, wherein: A is at least one rare earth element selected from trivalent rare earth elements; B is at least one halogen element selected from halogen elements; a=1, b=2 and c=7, a=2, b=1 and c=5, or a=3, b=1 and c=6; and y is greater than or equal to 0 and less than or equal to 0.5. According to another embodiment, the scintillator has a chemical formula of Tl.sub.aA.sub.bB.sub.c:yEu, wherein: A is an alkaline earth metal element; B is a halogen element; a=1, b=2 and c=5, or a=1, b=1 and c=3; and y is greater than or equal to 0 mol % and less than or equal to 50 mol %.

The present invention relates to scintillator compositions and related devices and methods. The scintillator compositions may include, for example, a scintillation compound and a dopant, the scintillation compound having the formula x.sub.1-x.sub.2-x.sub.3-x.sub.4 and x.sub.1 is Cs; x.sub.2 is Na; x.sub.3 is La, Gd, or Lu; and x.sub.4 is Br or I. In certain embodiments, the scintillator composition can include a single dopant or mixture of dopants.

A device comprising a nonlinear optical (NLO) material according to the formula XLi.sub.2Al.sub.4B.sub.6O.sub.20F. A device comprising a nonlinear optical material (NLO) according to the formula KSrCO.sub.3F, wherein the NLO comprises at least one single crystal. A nonlinear optical material selected from the group consisting of KSrCO.sub.3F Rb.sub.3Ba.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F and K.sub.3Sr.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F.

A device comprising a nonlinear optical (NLO) material according to the formula XLi.sub.2Al.sub.4B.sub.6O.sub.20F. A device comprising a nonlinear optical material (NLO) according to the formula KSrCO.sub.3F, wherein the NLO comprises at least one single crystal. A nonlinear optical material selected from the group consisting of KSrCO.sub.3F Rb.sub.3Ba.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F and K.sub.3Sr.sub.3Li.sub.2Al.sub.4B.sub.6O.sub.20F.

A laser apparatus including an optical element made of a CaF.sub.2 crystal and configured to transmit an ultraviolet laser beam obliquely incident on one surface of the optical element, the electric field axis of the P-polarized component of the laser beam propagating through the optical element coinciding with one axis contained in <111> of the CaF.sub.2 crystal, with the P-polarized component defined with respect to the one surface. A method for manufacturing an optical element, the method including causing a seed CaF.sub.2 crystal to undergo crystal growth along one axis contained in <111> to form an ingot, setting a cutting axis to be an axis inclining by an angle within 14.18±5° with respect to the crystal growth direction toward the direction of another axis contained in <111>, which differs from the crystal growth direction, and cutting the ingot along a plane perpendicular to the cutting axis.

A laser apparatus including an optical element made of a CaF.sub.2 crystal and configured to transmit an ultraviolet laser beam obliquely incident on one surface of the optical element, the electric field axis of the P-polarized component of the laser beam propagating through the optical element coinciding with one axis contained in <111> of the CaF.sub.2 crystal, with the P-polarized component defined with respect to the one surface. A method for manufacturing an optical element, the method including causing a seed CaF.sub.2 crystal to undergo crystal growth along one axis contained in <111> to form an ingot, setting a cutting axis to be an axis inclining by an angle within 14.18±5° with respect to the crystal growth direction toward the direction of another axis contained in <111>, which differs from the crystal growth direction, and cutting the ingot along a plane perpendicular to the cutting axis.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.

A scintillation crystal can include Ln.sub.(1-y)RE.sub.yX.sub.3, wherein Ln represents a rare earth element, RE represents a different rare earth element, y has a value in a range of 0 to 1, and X represents a halogen. In an embodiment, RE is Ce, and the scintillation crystal is doped with Sr, Ba, or a mixture thereof at a concentration of at least approximately 0.0002 wt. %. In another embodiment, the scintillation crystal can have unexpectedly improved linearity and unexpectedly improved energy resolution properties. In a further embodiment, a radiation detection system can include the scintillation crystal, a photosensor, and an electronics device. Such a radiation detection system can be useful in a variety of radiation imaging applications.