Development of a low-energy high resolution X-ray camera for high-energy gamma photon background environments. Issue 9 (2nd September 2017)

• Record Type: Journal Article
• Authors: Ando, Koki; Yamamoto, Seiichi; Kurita, Keisuke; Suzui, Nobuo; Yin, Yong-Gen; Ishii, Satomi; Kawachi, Naoki
• Is Part Of: Journal of nuclear science and technology. Volume 54:Issue 9(2017)
• Page Start: 933
• Page End: 939
• Publication Date: 2017-09-02
• Subjects: Cesium 137 -- X-ray -- experiment -- gamma ray -- high resolution -- background -- low energy; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2017.1323690
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: Although a high-energy gamma camera can obtain images of 137 Cs distribution by detecting the 662-keV gamma photons, its spatial resolution is reduced because high-energy gamma photons penetrate the edge of the pinhole collimator. To solve this problem, we developed a low-energy X-ray camera that detects the characteristic X-ray photons (32–37 keV) that are emitted from 137 Cs to obtain high resolution images. We used a 45 × 45 × 1-mm-thick NaI(Tl) scintillator that was encapsulated in 0.1-mm-thick aluminum and optically coupled to a 2-inch square, position sensitive photomultiplier tube (Hamamatsu Photonics, PSPMT:H12700 MOD) as an imaging detector. The imaging detector was encased in a 2-cm-thick tungsten alloy container and a pinhole collimator was attached to its camera head. The spatial resolution and sensitivity were ∼5 mm full-width at half-maximum and ∼0.6 cps/MBq for the 1.5-mm pinhole collimator 10 cm from the collimator surface, respectively. We administered 5 MBq of 137 Cs to a soybean seedling, imaged the distribution of radionuclides for six hours, and successfully obtained a high resolution image of it with our developed X-ray camera. We believe our camera will be a powerful tool for such 137 Cs imaging in plants.