Abstract: The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Abstract: M-center luminescence is used to measure radiation. An LiF crystal is excited with a 442 nm He-Cd laser because absorption measurements in LiF indicate the peak of the M-center absorption occurs at 443 nm. Laser stimulation produces an excited state of the M-center, which undergoes a very strong Stokes' shift. The peak of the M-center emission spectrum occurs at 665 nm with a half-width of 0.36 ev. Since the excitation wavelength differs significantly from the emission wavelength, measurement of the deep red emission can be done simultaneously with the excitation. The population of M-centers grows with increasing radiation damage, and therefore M-center lunimescence provides a basis for radiation dosimetry.

Abstract: The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material to a cryogenic temperature. The thermoluminescent material is then optically stimulated by exposure to ultraviolet light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light.

Abstract: The present invention constitutes a system for determining the amounts of ionizing radiation to which dosimeters using thermoluminescent materials have been exposed. In accordance with this system, the thermoluminescent materials which comprise the dosimeters are first cooled by contact with a cryogenic substance such as liquified nitrogen. The thermoluminescent materials are then optically stimulated by exposure to ultraviolet light. Thereafter, the amounts of visible light emitted by the thermoluminescent materials are detected and counted as the materials are allowed to warm up to room temperature. The amounts of luminescence exhibited by the materials are related to radiation exposure and provide a sensitive measure of radiation dosage. It has been discovered that the above procedure is most effective when heavily doped thermoluminescent materials are used and that the procedure allows many useful plastic materials to now be employed in dosimeter constructions.