The present invention aims to provide a thermoluminescent
phosphor for obtaining a two-dimensional or three-dimensional
dosimeter for measuring
dose absorbed by biological tissues, the thermoluminescent
phosphor exerting superior handleability, exhibiting superior
biological tissue equivalence, and having superior precision.The aforementioned object is achieved by means of a method for producing a thermoluminescent
phosphor, the method comprising a step A1 for mixing
lithium tetraborate,
boron oxide and
manganese dioxide, a step A2 for firing the aforementioned mixture at 770 to 840° C., and a step A3 for obtaining the thermoluminescent phosphor comprising
lithium triborate as a base material and
manganese as a luminescent center present in the base material by further adding and mixing
lithium tetraborate into the aforementioned fired product and then firing the mixture at 770 to 840° C., wherein the
molar ratio between the lithium tetraborate and the
boron oxide in the step A1 is 1:X (1<x≦4), the amount of the
manganese dioxide is 0.02 to 1.0
mass % relative to the total
mass of the
boron oxide and the total amount of the lithium tetraborate added in the steps A1 and A3, and the amount of the lithium tetraborate in the step A3 is (X−1) mol relative to 1 mol of the
boron oxide.