Comparison of manganese uptake and transport of maize seedlings by mini-PET camera.

Manganese is one of the most important essential micronutrients for the plants. To monitor its uptake and transport by radioactive tracking is a powerful method due to the no carrier added 52Mn in 10-12 moldm-3 concentration range. The generally used method is to measure the radioactivity of cut parts of plants by gamma-spectrometry. Only few studies reported about noninvasive measurement, using pairs of detectors connected in coincidence. We use a full ring MiniPET machine for this purpose to dynamically visualize the uptake and distribution of the radionuclide in 4D. The results are controlled with the conventional gamma spectroscopy after chopping the plants into six parts. The study of stress tolerance initiated by PEG 6000 in different hybrids of maize is also presented as possible application for the phenotyping of plants by PET camera.

Thermoluminescence properties of 30Y2O3·30P2O5·40SiO2 vitroceramics in mixed neutron-gamma fields.

Powders of the 30Y2O3·30P2O5·40SiO2 vitroceramic were irradiated with broad spectrum d+Be (Eneutron = 0-14.5 MeV) and quasi-monoenergetic d+D neutrons (Eneutron = 12.4 ± 0.22 MeV). The absorbed dose of d+Be neutrons was Dn = 2.52 ± 8% Gy with Dγ = 0.22 ± 14% Gy accompanied gamma absorbed dose. The absorbed dose of d+D neutrons was Dn = 1.43 ± 8% Gy with Dγ = 0.21 ± 14% Gy gamma absorbed dose. The thermoluminescence (TL) induced in the vitroceramics was studied. Both the gamma and neutron component contributed to the TL signals. The relative neutron sensitivities were [(TLn/TLγ)/(Dn/Dγ)]d+Be = 0.04 ± 60% and [(TLn/TLγ)/(Dn/Dγ)]d+D = 0.11 ± 43%.

Coordinated underground measurements of gamma-ray emitting radionuclides for plasma physics research.

Forty-eight samples made of CaF2, LiF and YVO4 were placed inside the KSTAR Tokamak and irradiated by neutrons and charged particles from eight plasma pulses. The aim was to provide information for plasma diagnostics. Due to the short pulse durations, the activities induced in the samples were low and therefore measurements were performed in five low-background underground laboratories. Details of the underground measurements, together with data on the quality control amongst the radiometric laboratories, are presented.