Radiation storage phosphor and applications

A process for making a photoexcitable storage phosphor which comprises at least one rare earth element in the trivalent +3 oxidation state and wherein upon irradiation by X-ray, γ-ray or UV radiation the trivalent +3 oxidation state is reduced to divalent +2 oxidation state, and the photoexcitable storage phosphor comprises submicron size particles,

• wherein the photoexcitable storage phosphor is represented by a formula (A):
• MeX1X2:RE3+, wherein Me represents a metal ion,
• X1 and X1 is independently a halogen atom selected from the group consisting of chlorine, fluorine, bromine, and iodine;
• and RE is a rare earth element, and comprising the at least one rare earth element in a concentration of about 0.01% to about 5% relative to the metal halide concentration, the process comprising combining a first solution and a second solution to form a reaction mixture, wherein the first solution comprises a metal halide and a rare earth halide, wherein the halides are independently selected from the group consisting of chloride, bromide and iodide, and the second solution comprises a fluoride species.

A process for recording and reproducing an image comprising the steps of:

• (i) exposing a radiation image storage panel comprising a photoexcitable storage phosphor according to which comprises at least one rare earth element in the trivalent +3 oxidation state and wherein upon irradiation by X-ray, γ-ray or UV radiation the trivalent +3 oxidation state is reduced to divalent +2 oxidation state, and the photoexcitable storage phosphor comprises submicron size particles to radiation which has passed through or radiated from an object;
• (ii) exposing the radiation image storage panel to an electromagnetic wave having a wavelength within a range of exciting light wavelength of the photoexcitable storage phosphor, and
• (iii) detecting the emitted light,
• wherein step (ii) comprises gating the exciting light and the emitted light to allow the detector to be closed when the phosphor is exposed to excitation light and to open for at least a portion of time while the phosphor is not exposed to excitation light and wherein the detecting step (iii further comprises employing a lock-in amplifier and a modulation technique to modulate a signal generated from the detected emitted light.

A process for recording and reproducing an image comprising the steps of:

• (i) exposing a radiation image storage panel comprising a photoexcitable storage phosphor according to which comprises at least one rare earth element in the trivalent +3 oxidation state and wherein upon irradiation by X-ray, γ-ray or UV radiation the trivalent +3 oxidation state is reduced to divalent +2 oxidation state, and the photoexcitable storage phosphor comprises submicron size particles, to radiation which has passed through or radiated from an object:
• (ii) exposing the radiation image storage panel to an electromagnetic wave having a wavelength within a range of exciting light wavelength of the photoexcitable storage phosphor, and
• (iii) detecting the emitted light,
• wherein step (ii) comprises gating the exciting light and the emitted light to allow the detector to be closed when the phosphor is exposed to excitation light and to open for at least a portion of time while the phosphor is not exposed to excitation light and wherein the gating step provides a gated excitation/emission with a 180 degree phase difference.