ESR Dosimetry and Dating toward 21st Century

다국어 초록 (Multilingual Abstract)

Dating and dosimetry using electron spin resonance (ESR) in 20th century developed at both Yamaguchi University and Osaka University have been reviewed with emphasis on new prospects and strategies in 21st century. Natural radiation have been generating radicals that accumulated in archaeological and geological materials. ESR detects these radicals and the ESR signal intensity is proportional to the radiation dose and therefore the age. The assessment of the total dose of natural radiation and the annual dose rate give their ESR ages. The ESR dating of stalactites and stalagmites at Akiyoshi cave in Yamaguchi prefecture in 1975 was extended to anthropological dating using bones and tooth enamel excavated in Greek Petralona cave. Fossils of shells and corals gave the ages of marine terraces and sea-level changes. Quartz grains gave the ages of geothermal alteration and fault movements. Future ESR dating of ices at outer planets anf their satellite are also investigated as basic studies for ices od H2O, CO2, SO2 as well as terrestrial hydrates in laboratory. Atomic bomb radiation dosimetry at Hiroshima and Nagasaki using ESR lead to the dosimetry of personnel, Chernobyl and JCO criticality accidents. Monitoring of radiation dose with sensitive materials with tissue equivalence are being developed. Finally a new scanning ESR imaging apparatus (a near field microwave microscope) developed in our laboratory gave ESR images of radicals from fossils to Si-CVD and diamond films as summarized in my book in 2002.

국문 초록 (Abstract)

영어논문