Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera
Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera
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DOI：
10.1016/j.jenvrad.2015.04.009
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发表时间：
2016-01-01
影响因子：
2.3
通讯作者：
Fujimaki, Shu
中科院分区：
文献类型：
--
作者：
Kawachi, Naoki;Yin, Yong-Gen;Fujimaki, Shu
我们开发了一种专门用于植物营养研究的新型伽马相机，并成功地对完整植物中Cs-137的摄取和分配进行了实时成像。伽马相机是专门为Cs-137(662键)的高能伽马光子设计的。为了获得可靠的图像，使用了由钨重合金制成的针孔准直器来减少伽马光子的穿透和散射。采用掺Ce的Gd3Al2Ga3O12单晶闪烁体，灵敏度高，无天然放射性，无吸湿性。闪烁体的阵列块与高量子效率的位置灵敏光电倍增管耦合，以获得精确的图像。完成的伽马相机对Cs-137的灵敏度为0.83count S(-1)mBq(-1)，能量窗为600~730keV，空间分辨率为23.5 mm。我们利用这台伽马相机研究了水培大豆植株，并用2.0MBq的Cs-137饲喂了6天，以可视化和研究植物地上部分的运输动态。取食几小时后，CS-137逐渐在枝条中出现，并在生长的豆荚和种子中优先和密集地积累，在成熟的叶片中几乎没有积累。我们的结果还表明，这种伽马相机方法可以作为一种实用的分析工具，用于育种作物和改进栽培技术，从而降低放射性铯在植物可消耗部分中的积累量。(C)2015年提交人。爱思唯尔有限公司出版。
We developed a new gamma camera specifically for plant nutritional research and successfully performed live imaging of the uptake and partitioning of Cs-137 in intact plants. The gamma camera was specially designed for high-energy gamma photons from Cs-137 (662 key). To obtain reliable images, a pinhole collimator made of tungsten heavy alloy was used to reduce penetration and scattering of gamma photons. A single-crystal scintillator, Ce-doped Gd3Al2Ga3O12, with high sensitivity, no natural radioactivity, and no hygroscopicity was used. The array block of the scintillator was coupled to a high-quantum efficiency position sensitive photomultiplier tube to obtain accurate images. The completed gamma camera had a sensitivity of 0.83 count s(-1) MBq(-1) for Cs-137 with an energy window from 600 keV to 730 keV, and a spatial resolution of 23.5 mm. We used this gamma camera to study soybean plants that were hydroponically grown and fed with 2.0 MBq of Cs-137 for 6 days to visualize and investigate the transport dynamics in aerial plant parts. Cs-137 gradually appeared in the shoot several hours after feeding, and then accumulated preferentially and intensively in growing pods and seeds; very little accumulation was observed in mature leaves. Our results also suggested that this gamma-camera method may serve as a practical analyzing tool for breeding crops and improving cultivation techniques resulting in low accumulation of radiocesium into the consumable parts of plants. (C) 2015 The Authors. Published by Elsevier Ltd.