Radiation image storage panel and its preparation

1. A radiation image storage panel comprising a support, a phosphor matrix compound layer covering a surface of the support at a coverage percentage of 95% or more, and a stimulable phosphor layer formed on the phosphor matrix compound layer, the stimulable phosphor layer comprising multiple prismatic stimulable phosphor crystals standing on the phosphor matrix compound layer, wherein said phosphor matrix compound layer excludes an activator.

2. A process for preparing a radiation image storage panel of claim 1 comprising the steps of:

forming a phosphor matrix compound layer on a surface of a support by vapor deposition whereby the phosphor matrix compound layer covers the surface at a coverage percentage of 95% or more; and

placing a stimulable phosphor layer comprising multiple prismatic stimulable phosphor crystals on the phosphor matrix compound layer by vapor deposition.

3. The process of claim 2 , wherein the step of forming a phosphor matrix compound layer by vapor deposition and the step of placing a stimulable phosphor layer by vapor deposition are performed successively.

4. The process of claim 2 , wherein the stimulable phosphor layer comprises a stimulable phosphor comprising a phosphor matrix element and an activator element, and the step of placing a stimulable phosphor layer by vapor deposition is performed by vaporizing a vaporization source comprising a phosphor matrix compound and a vaporization source comprising an activator compound simultaneously and depositing the vaporized sources on the matrix compound layer.

5. The process of claim 2 , wherein the step of placing a stimulable phosphor layer by vapor deposition is performed at a pressure of 0.3 to 3 Pa in the presence of an inert gas.

6. The radiation image storage panel of claim 1 , wherein the stimulable phosphor layer is placed on the phosphor matrix compound layer by vapor deposition.

7. The radiation image storage panel of claim 1 , wherein the phosphor matrix compound layer is placed on the surface of the support by vapor deposition.

8. The radiation image storage panel of claim 1 , wherein the phosphor matrix compound layer comprises phosphor matrix compound particles which are placed on the surface of the support and combined with each other.

9. The radiation image storage panel of claim 1 , wherein the phosphor matrix compound layer has a thickness in the range of 50 nm to 100 μm.

10. The radiation image storage panel of claim 1 , wherein the stimulable phosphor is an alkali metal halide phosphor having the formula (I):

M I X· a M II X′ 2 ·b M III X″ 3 :z A  (I)

in which M I is at least one alkali metal element selected from the group consisting of Li, Na, K, Rb and Cs; M II is at least one alkaline earth metal element or divalent metal element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Ni, Cu, Zn d Cd; M III is at least one rare earth element or trivalent metal element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga and In; each of each of X, X′ and X″ independently is at least one halogen selected from the group consisting of F, Cl, Br and I; A is at least one rare earth element or metal element selected from the group consisting of Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mg, Cu, and Bi; and a, b and z are numbers satisfying the conditions of 0≦a<0.5, 0≦b<0.5 and 0<z≦1.0, respectively.

11. The radiation image storage panel of claim 1 , wherein the stimulable phosphor is an europium activated cesium bromide phosphor.