Methods for rapidly stimulating luminescent phosphors and recovering information therefrom
OwnerJean Gasiot, Peter F. Braunlich +1inventors
InventorsJean Gasiot, Peter F. Braunlich, Jean P. Fillard
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Abstract
Disclosed is a method for rapidly stimulating luminescent phosphors using laser beams. The laser beam must strike the luminous phosphor with an intensity sufficient to cause rapid release of luminescent energy stored within the phosphor as a result of previous exposure to ionizing radiation. Emission of the luminescent energy can occur within very brief peiods of time, for example, less than 100 nanoseconds. The invention also includes a method for determining the amount of ionizing radiation to which a luminescent phosphor was exposed. Also disclosed is an apparatus for carrying out these methods.
Claims17
A method for rapidly and optically stimulating luminescent phosphors to cause luminescent energy previously stored in the luminescent phosphors to be rapidly released, comprising:
- directing an intense beam of photons from a laser at the luminescent phosphor for a period of time less than one millisecond and with a photon flux density of at least 5.times.10.sup.19 photons per second and per square millimeter;
- said beam of photons having a wavelength approximately equal to the stimulation wavelength for the phosphor.
A method for determining the amount of ionizing radiation which has impinged upon a unit of luminescent phosphor, comprising:
- striking the unit of luminescent phosphor with a stimulating beam of photons from a laser;
- said stimulating beam of photons being emitted from the laser at a wavelength approximately equal to a stimulation wavelength of the phosphor for a period of time equal to less than 1 microsecond and at a photon flux density of at least 5.times.10.sup.19 photons per second and per square millimeter;
- measuring the peak intensity of the luminescent emission beam produced by the unit of luminescent phosphor as a result of the previous step;
- correlating the measured peak intensity of the luminescent emission with experimentally derived standard values associated with the phosphor being used which relate phosphor emission beam peak intensity to the amount of ionizing radiation to determine the amount of ionizing radiation which impinged upon the unit of luminescent phosphor.
A method for determining the amount of ionizing radiation which has impinged upon a unit of luminescent phosphor, comprising:
- striking the unit of luminescent phosphor with a stimulating beam of photons from a laser;
- said stimulating beam of photons being emitted from the laser at a wavelength approximately equal to a stimulation wavelength of the phosphor for a period of time equal to less than 1 microsecond and at a photon flux density of at least 5.times.10.sup.19 photons per second and per square millimeter;
- measuring the intensity of the luminescent emission beam produced by the unit of luminescent phosphor as a result of the previous step and integrating this value over time to produce a measurement of the total quantity of luminescent emission;
- comparing said measurement of the total quantity of luminescent emission with experimentally derived standard values associated with the phosphor being used which relate total quantity of luminescent emission to amount of ionizing radiation to determine the amount of ionizing radiation which impinged upon the unit of luminescent phosphor.
Dependencies are inferred from the claim text.