Abstract
The isotope selectivity of computed tomography (CT) imaging based on nuclear resonance fluorescence (NRF) transmission method using a quasi-monochromatic laser Compton scattering (LCS) gamma-ray beam in the MeV region was demonstrated at the Ultra Violet Synchrotron Orbital Radiation-III (UVSOR-III) Synchrotron Radiation Facility (Institute of Molecular Science, National Institute of Natural Science) for two enriched lead isotope rods ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">206</sup> Pb and <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">208</sup> Pb) implanted in an aluminum cylinder. Since these two rods show the same gamma-ray attenuation in atomic processes, it is impossible to differentiate between them using a standard Gamma-CT technique based on atomic attenuation of gamma rays. The LCS gamma-ray beam had a maximum energy of 5.528 MeV and an intensity of approximately 5.5 photons/s/eV at the resonance energy (J <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">π</sup> = 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</sup> at 5.512 MeV in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">208</sup> Pb). A lead collimator with a hole diameter of 1 mm was used to define the size of the LCS gamma-ray beam at the CT target. The CT image of the <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">208</sup> Pb rod was selectively obtained with a 2-mm pixel size resolution, which was determined by the horizontal step size of the CT stage.
Highlights
Science) for two enriched lead isotope rods (206 Pb and 208 Pb) implanted in an aluminum cylinder
Takehito Hayakawa and Toshiyuki Shizuma are with the Tokai Quantum Beam Science Center, National Institutes for Quantum and Radiological Science and Technology (QST), Naka 319-1106, Japan (e-mail: hayakawa.takehito@qst.go.jp; shizuma.toshiyuki@qst.go.jp)
Masaki Fujimoto is with the National Institute of Natural Science, Institute of Molecular Science, Ultra Violet Synchrotron Orbital Radiation (UVSOR) Synchrotron Radiation Facility, Okazaki 444-8585, Japan (e-mail: fmoto@ims.ac.jp)
Summary
ONDESTRUCTIVE assay (NDA) technology, which is used to identify specific isotopes in a substance, Manuscript received March 13, 2020; revised May 29, 2020; accepted. Bertozzi et al [1] proposed the nuclear resonance fluorescence (NRF) process [6] with Bremsstrahlung gamma-ray beams for the measurement of the isotopes of interest. The aim of this study was to demonstrate the isotope selectivity of NRF-CT imaging using two different isotope-enriched lead rods (206 Pb and 208 Pb) Because these two rods exhibit the same gamma-ray attenuation in atomic processes, it is impossible to distinguish the two rods using a standard CT technique based on the atomic attenuation of gamma rays. The energy of the gamma-ray beam was increased to enable excitation at 5.512 MeV, as the NRF cross section was two times larger than that at 5.292 MeV in previous work [16]. An increased number of data points were measured using an LCS beam with a smaller diameter of 1 mm and a scanning step of 2 mm to obtain a CT image with a higher spatial resolution than the previous work [16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
