Three-layer GSO depth-of-interaction detector for high-energy gamma camera

Yamamoto, Seiichi; Watabe, Hiroshi; Kawachi, Naoki; Fujimaki, Shu; Katô, Katsuhiko; Hatazawa, Jun

doi:10.1016/j.nima.2014.01.011

Cited by 10 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Spatial resolution in the area near the edge of FOV was worse because of a parallax error caused by oblique incidence of gamma photons into multiple scintillator sections at the edges. In general, a gamma photon with higher energy should cause a more serious parallax error and worse spatial resolution because it can reach deeper position of the scintillator (Yamamoto and Ishibashi, 1998;Yamamoto et al, 2014).…”

Section: Evaluation Of the Camera Systemmentioning

confidence: 99%

Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera

Kawachi

Yin

Suzui

et al. 2016

Journal of Environmental Radioactivity

View full text Add to dashboard Cite

We developed a new gamma camera specifically for plant nutritional research and successfully performed live imaging of the uptake and partitioning of (137)Cs in intact plants. The gamma camera was specially designed for high-energy gamma photons from (137)Cs (662 keV). 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 (137)Cs 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 (137)Cs for 6 days to visualize and investigate the transport dynamics in aerial plant parts. (137)Cs 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.

show abstract

Section: Evaluation Of the Camera Systemmentioning

confidence: 99%

Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera

Kawachi

Yin

Suzui

et al. 2016

Journal of Environmental Radioactivity

View full text Add to dashboard Cite

show abstract

“…The gamma cameras can be classified into three types: a pinhole type [2][3][4] and a coded aperture type [5][6][7][8][9], each of which has a collimator, and a Compton type camera [10][11][12][13][14] which does not need the collimator. Each type has different characteristics due to the different imaging principles.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic gamma camera for use in high dose environments

Ueno

Takahashi

Ishitsu

et al. 2016

Nuclear Instruments and Methods in Physics Research Section A:

View full text Add to dashboard Cite

We developed a pinhole gamma camera to measure distributions of radioactive material contaminants and to identify radionuclides in extraordinarily high dose regions (1,000 mSv/h). The developed gamma camera is characterized by: (1) tolerance for high dose rate environments; (2) high spatial and spectral resolution for identifying unknown contaminating sources; and (3) good usability for being carried on a robot and remotely controlled. These are achieved by using a compact pixelated detector module with CdTe semiconductors, efficient shielding, and a fine resolution pinhole collimator. The gamma camera weighs less than 100 kg, and its field of view is an 8 m square in the case of a distance of 10 m and its image is divided into 256 (16 x 16) pixels. From the laboratory test, we found the energy resolution at the 662 keV photopeak was 2.3% FWHM, which is enough to identify the radionuclides. We found that the count rate per background dose rate was 220 cps h/mSv and the maximum count rate was 300 kcps, so the maximum dose rate of the environment where the gamma camera can be operated was calculated as 1,400 mSv/h. We investigated the reactor building of Unit 1 at the Fukushima Dai-ichi Nuclear Power Plant using the gamma camera and could identify the unknown contaminating source in the dose rate environment that was as high as 659 mSv/h.

show abstract

“…An imaging system has a good advantage for this purpose because it can provide information of changing distribution of a radiotracer in a living plant. Up to the present time, such systems detecting gamma photons [5,6] and beta particles [7] have been employed in this field. However, high resolution imaging of gamma photons from 137 Cs (662 keV) and 134 Cs (605 keV and 795 keV) is difficult because the high energy gamma photons penetrate the pin-hole collimator.…”

Section: Introductionmentioning

confidence: 99%