Synthesis, luminescent and dosimetric properties of ultrafine oxide ceramics for high-dose dosimetry of ionizing radiation

Thermoluminescent and dosimetric properties of ultrafine alumina and zirconia ceramics exposed to high- dose pulsed electron beam (130 keV, 1.5 kGy per one pulse) were studied. To synthesize ceramics with dif- ferent sizes of crystallites, the authors sintered nanopowder compacts in air in an electric furnace at T=700- 1700 оС, and exposed them to high-energy electrons (1.4 MeV) with high power density. It was found that ce- ramics annealing at Т>1000 оС greatly increases crystallite sizes, which correlates with a significant growth of intensity of thermoluminescent peaks. Maximum thermoluminescent response is present in the ceramics that were obtained with an electron-beam method. This is due to formation of radiation-induced trapping and luminescence centers during synthesis. Analysis of dose dependences of thermoluminescence of the irradiated a-Al2O3 и ZrO2 ceramics showed that these dependences are predominantly sublinear. Unlike their single- crystalline modifications, alumina-based ceramics have anomalous fading, which value increases as crystal- lites grow in size. The presence of the intensive isolated peak of thermoluminescence and sublinear character of the majority of dose dependences prove usability of the oxide ceramics synthesized in this work for meas- uring high doses of pulsed electron beams (unities-tens of kGy). Alumina-based ceramics require correction of thermoluminescent response by a fading value.