Extended utilization of a Ge/Ga reference source as a mock F source in the ionization chamber calibration.

Possible extended utilization of a Ge/Ga source as a surrogate F reference source was studied. Some effects and uncertainties might arise from the difference of constructions between chambers that were used in the source calibration and those practically in use. To extend utilization of the surrogate source, response ratio of real F to Ge/Ga sources were determined for three models of chambers.

Screening test for radioactivity of self-consumption products in Fukushima after the Fukushima Dai-ichi NPP accident in Japan.

A food inspection service system for home grown products or wild plants collected by individual consumers for self-consumption was implemented in Fukushima in Nov. 2012. About 500 NaI(Tl) scintillation spectrometers were distributed to 300 or more temporary testing laboratories which were set up in public halls or meeting places of the municipalities.

Uniformity measurement of wide area reference sources for beta emitters.

When conducting uniformity measurements of a wide area reference source with a detector having a window of a size similar to that of a gridded individual portion area on the source, it is important to carefully consider neighbor effects on measuring emission rates of the individual target portion resulting from the gap between the source and detector window. Optimization of the uniformity measurement conditions was studied for beta-emitting wide area reference sources in this study. A measurement system consisting of a PR-gas (Ar: 90%+CH4: 10%) flow type windowed proportional counter and a motorized XY stage was installed.

Induction of DNA damage, including abasic sites, in plasmid DNA by carbon ion and X-ray irradiation.

DNA from plasmid pUC18 was irradiated with low-LET (13 keV/μm) or high-LET (60 keV/μm) carbon ions or X-rays (4 keV/μm) in solutions containing several concentrations of Tris (0.66-200 mM) to determine the yield of abasic (AP) sites and the effect of scavenging capacity. The yield of AP sites, detected as single-strand breaks (SSB) after digestion with E.