Application of rare earth doped apatite to radioluminography

将类似磷灰石化合物的氯磷酸锶晶体和氯磷酸钡晶体应用于放射发光荧光粉中，以研制一种辐射能量传感器。经x射线照射后，掺有铕离子或钆离子的氯磷酸锶晶体和氯磷酸钡晶体表现出明亮的光激发光（PSL）。掺Eu或gd的氯磷酸锶的PSL强度高于掺Eu或gd的氯磷酸钡。铕或钆掺杂的氯磷酸钡在紫外线照射后呈现出暗PSL。而铕或钆掺杂的氯磷酸锶在紫外线或可见光照射后表现出PSL。此外，在紫外线或可见光照射下，可以观察到Eu-或gd -掺杂的氯磷酸锶与Eu-或gd -掺杂的氯磷酸锶在x射线照射后，由于电子捕获而产生的热释光和ESR信号。这些结果表明，铕或钆掺杂的氯磷酸锶在比氯磷酸锶（主晶体）带隙能量更低的射线照射下形成了电子陷阱中心，即铕或钆掺杂的氯磷酸锶可以用作辐射能量传感器。

Strontium chlorophosphate crystal and barium chlorophosphate crystal which are analogous apatite compounds, were attempted to apply to a luminescence phosphor for radioluminography, in order to develop an energy sensor of radiation. Strontium chlorophosphate crystal and barium chlorophosphate crystal doped with europium ion or gadolinium ion exhibited a bright photostimulated luminescence (PSL) after X-ray irradiation. The PSL intensity was higher in Eu- or Gd-doped strontium chlorophosphate than in Eu- or Gd-doped barium chlorophosphate.Eu- or Gd-doped barium chlorophosphate exhibited dark PSL after ultraviolet irradiation. However, Eu- or Gd-doped strontium chlorophosphate exhibited PSL after ultraviolet irradiation or visible ray irradiation. Furthermore, thermoluminescence and ESR signal due to electron captured with electron trap was observed in Eu- or Gd-doped strontium chlorophosphate after ultraviolet or visible ray irradiation in analogy with Eu- or Gd-doped strontium chlorophosphate after X-ray irradiation. These results suggest that electron trap center is formed in Eu- or Gd-doped strontium chlorophosphate irradiated with lower energy ray than band gap energy of strontium chlorophosphate (host crystal), that is, Eu- or Gd-doped strontium chlorophosphate is available for an energy sensor of radiation.