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Journal Articles

Development of event-type neutron imaging detectors at the energy-resolved neutron imaging system RADEN at J-PARC

Parker, J. D.*; Harada, Masahide; Hayashida, Hirotoshi*; Hiroi, Kosuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Nakatani, Takeshi; Oikawa, Kenichi; Segawa, Mariko; Shinohara, Takenao; et al.

Materials Research Proceedings, Vol.15, p.102 - 107, 2020/05

Journal Articles

Electron-tracking Compton camera imaging of technetium-95m

Hatsukawa, Yuichi*; Hayakawa, Takehito*; Tsukada, Kazuaki; Hashimoto, Kazuyuki*; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.

PLOS ONE (Internet), 13(12), p.e0208909_1 - e0208909_12, 2018/12

AA2018-0639.pdf:2.39MB

 Times Cited Count:2 Percentile:30.45(Multidisciplinary Sciences)

Imaging of $$^{95m}$$Tc radioisotope was conducted using an electron tracking-Compton camera (ETCC). $$^{95m}$$Tc emits 204, 582, and 835 keV $$gamma$$ rays, and was produced in the $$^{95}$$Mo(p,n)$$^{95m}$$Tc reaction with a $$^{95}$$Mo-enriched target. The recycling of the $$^{95}$$Mo-enriched molybdenum trioxide was investigated, and the recycled yield of $$^{95}$$Mo was achieved to be 70% - 90%. The images were obtained with each of the three $$gamma$$ rays. Results showed that the spatial resolution increases with increasing $$gamma$$-ray energy, and suggested that the ETCC with high-energy $$gamma$$-ray emitters such as $$^{95m}$$Tc is useful for the medical imaging of deep tissue and organs in the human body.

Journal Articles

Production of $$^{rm 95m}$$Tc for Compton camera imaging

Hatsukawa, Yuichi; Hashimoto, Kazuyuki; Tsukada, Kazuaki; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Nagai, Yasuki; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1283 - 1285, 2015/02

 Times Cited Count:2 Percentile:17.75(Chemistry, Analytical)

Technetium-99m ($$^{rm 99m}$$Tc) is used in radioactive medical diagonostic tests, for example as a radioactive tracer that medical equipment can detect in the human body. It is well suited to the role because it emits readily detectable 141 keV $$gamma$$ rays, and its half-life is 6.01 hours (meaning that about 94% of it decays to technetium-99 in 24 hours). There are at least 31 commonly used radiopharmaceuticals based on technetium-99m for imaging and functional studies of the brain, myocardium, thyroid, lungs, liver, gallbladder, kidneys, skeleton, blood, and tumors. Recent years, with the develop-ment of the Compton camera which can realize high position resolution, technetium isotopes emitting high energy $$gamma$$-rays are required. In this study, technetium-95m which emits some $$gamma$$ rays around 800 keV was produced by the $$^{95}$$Mo(p,n)$$^{rm 95m}$$Tc reaction.

Journal Articles

Quantitative measurements of element distributions using the neutron-transmission resonance-absorption method

Harada, Masahide; Parker, J. D.*; Sawano, Tatsuya*; Kubo, Hidetoshi*; Tanimori, Toru*; Shinohara, Takenao; Maekawa, Fujio; Sakai, Kenji

Physics Procedia, 43, p.314 - 322, 2013/00

 Times Cited Count:1 Percentile:53.37

The purposes of this study are to perform Neutron Resonance Absorption NRA test experiments using the Micro Pixel Chamber, and to confirm its quantitativity. The detector was located at 14.5 m from the moderator in the experimental room of NOBORU. The samples, consisting of thin Tantalum (Ta) foils, with thicknesses of 5, 10, 20 and 100 $$mu$$m, were placed individually at 15 cm upstream from the detector. In the experiment, the transmission spectra with the Ta samples and no sample were obtained. Background components were not so small in these measurements. From the neutron transport simulation, it was surmised that the origin of this background was due to scattering of neutrons in the experimental room. Therefore, the assumed background components were subtracted from the measurement data. Finally, it was found that the difference between the measurement data and the nuclear data was within about 7%.

Journal Articles

A Gas-based neutron imaging detector with individual read-outs

Nakamura, Tatsuya; Tanaka, Hiroki; Yamagishi, Hideshi; Soyama, Kazuhiko; Aizawa, Kazuya; Ochi, Atsuhiko*; Tanimori, Toru*

Nuclear Instruments and Methods in Physics Research A, 573(1-2), p.187 - 190, 2007/04

 Times Cited Count:8 Percentile:56.54(Instruments & Instrumentation)

We have been developing a neutron imaging gas detector with a high spatial resolution and with a high temporal response for the neutron scattering instruments at the pulsed neutron source in the Japan proton accelerator research complex. The gas detector system with individual read-outs was developed to meet the requirements for the instruments for neutron reflectometry or for small angle neutron scattering. The performances of the prototype detector using a multi-wire (MW) or micro-strip (MS) detector head were evaluated using a collimated neutron beam, and we confirmed the MS detector exhibiting a spatial resolution of 1.5 mm and a pulse-pair resolution of about 100 ns with a gas pressure of 6 atm helium with a mixture of 30% CF$$_{4}$$. The performances for the MS detector were also evaluated up to the total gas pressure of 8 atm.

Oral presentation

Development of two-dimensional neutron gas detector with a high spatial resolution, 2

Tanaka, Hiroki; Nakamura, Tatsuya; Yamagishi, Hideshi; Soyama, Kazuhiko; Aizawa, Kazuya; Ochi, Atsuhiko*; Tanimori, Toru*

no journal, , 

no abstracts in English

Oral presentation

Development of 2D position sensitive neutron detector with a high spatial resolution, 3

Yamagishi, Hideshi; Nakamura, Tatsuya; Tanaka, Hiroki; Soyama, Kazuhiko; Aizawa, Kazuya; Ochi, Atsuhiko*; Tanimori, Toru*

no journal, , 

no abstracts in English

Oral presentation

Development of 2D position sensitive neutron detector with a micro-pixel device

Yamagishi, Hideshi; Nakamura, Tatsuya; Soyama, Kazuhiko; Aizawa, Kazuya; Tanaka, Hiroki*; Tanimori, Toru*

no journal, , 

no abstracts in English

Oral presentation

Irradiation tests for 2-dimensional micro-pixel gas chamber using Cf-252 neutrons

To, Kentaro; Yamagishi, Hideshi; Soyama, Kazuhiko; Ochi, Atsuhiko*; Tanimori, Toru*

no journal, , 

Neutron scattering experiment using high intensity pulsed neutrons will be carried out in Materials and Life Science Facility at J-PARC. Several features are desired for neutron detectors in the experiments. The detectors require features such as a good spatial resolution, high detection efficiency, and fast response. In view of these requirements, we have developed a 2D position sensitive neutron detector system consist of micro-pattern detector array as detection device. In this presentation, characteristics of the 2D micro-pixel gas chamber (MPGC) under Cf-252 neutron irradiation are reported. The irradiation experiments were carried out using a mixture gas of helium and carbon tetrafluoride with total pressures of 4 and 5 atm. Signal pulse peak of neutrons can be identified and be discriminated easily from background noise generated in lower channels. Here, degradation of gas gain arisen from a charge up effect was not observed in our MPGC system.

Oral presentation

Characteristics of 2-dimensional micro-pixel gas chamber under Cf-252 neutron irradiation

To, Kentaro; Yamagishi, Hideshi; Soyama, Kazuhiko; Ochi, Atsuhiko*; Tanimori, Toru*

no journal, , 

Neutron scattering experiments using high intensity pulsed neutrons will be carried out in Materials and Life Science Facility at J-PARC. Detectors using in the facility require features such as a good spatial resolution, high detection efficiency, fast response, etc. We have developed a 2D position sensitive neutron detector system consist of micro-pattern detector array such as microstrip and miltiwire detector array. In this presentation, characteristics of the 2D micro-pixel gas chamber system under Cf-252 neutron irradiation are reported. Detection area used in this experiment is 50$$times$$50 mm$$^{2}$$ and pitches of both axes, anodes and cathodes, are 0.4 mm. Irradiation were carried out with a mixture gas of helium-3 and carbon tetrafluoride. It can be seen that signal pulse peaks of neutrons can be identified and these pulse peaks is discriminated easily from background noises. Here, degradation of gas gain arisen from a charge up effect was not observed in our system.

Oral presentation

Two-dimensional neutron gas detector using micro-pixel detector head and individual readout method

To, Kentaro; Yamagishi, Hideshi*; Sakasai, Kaoru; Nakamura, Tatsuya; Soyama, Kazuhiko; Ochi, Atsuhiko*; Tanimori, Toru*

no journal, , 

Neutron scattering experiments involving high-intensity and wide-energy pulsed neutrons are expected to be conducted at the MLF in the J-PARC. These experiments require neutron detectors with features such as a two-dimensional detection area, good spatial resolution, high detection efficiency, and a fast response time. In this study, a gas-based neutron detection system with individual readout method and consisting of a micro-pixel detector head was developed, and preliminary experiments were conducted under neutrons irradiation. To examine the operation of the detector system, the total projection ranges of the secondary particles emitted by the nuclear reaction between neutrons and $$^{3}$$He nuclei are measured and compared with the values obtained from a Monte Carlo simulation. Since the measured projection ranges of the secondary particles agree with the ranges obtained from the Monte Carlo simulation, it is concluded that the operation of the developed system is satisfactory.

Oral presentation

Measurement of two-dimensional material distributions using the neutron-transmission resonance-absorption method

Harada, Masahide; Parker, J.*; Sawano, Tatsuya*; Kubo, Hidetoshi*; Tanimori, Toru*; Shinohara, Takenao; Maekawa, Fujio

no journal, , 

no abstracts in English

Oral presentation

Quantitative measurements of material distributions using the neutron-transmission resonance-absorption method

Harada, Masahide; Parker, J.*; Sawano, Tatsuya*; Kubo, Hidetoshi*; Tanimori, Toru*; Shinohara, Takenao; Maekawa, Fujio

no journal, , 

no abstracts in English

Oral presentation

Quantitative measurements of element distributions using neutron-transmission resonance-absorption method

Harada, Masahide; Parker, J.*; Sawano, Tatsuya*; Kubo, Hidetoshi*; Tanimori, Toru*; Shinohara, Takenao; Maekawa, Fujio

no journal, , 

Oral presentation

Neutron beam fundamentals development in Japan; Utilization of steady state and pulsed neutrons

Kakurai, Kazuhisa; Oku, Takayuki; Hayashida, Hirotoshi; Sakai, Kenji; Shinohara, Takenao; Nakamura, Mitsutaka; Wakimoto, Shuichi; Yamazaki, Dai; Sakasai, Kaoru; Soyama, Kazuhiko; et al.

no journal, , 

Oral presentation

Advances in neutron beam fundamentals development

Kakurai, Kazuhisa; Kiyanagi, Yoshiaki; Oyama, Kenji*; Ino, Takashi*; Takahashi, Hiroyuki*; Tanimori, Toru*

no journal, , 

no abstracts in English

Oral presentation

The Performance evaluation of electron tracking Compton camera for medical imaging

Sonoda, Shinya*; Nabetani, Akira*; Kimura, Hiroyuki*; Kabuki, Shigeto*; Takada, Atsushi*; Kubo, Hidetoshi*; Kimura, Shotaro*; Sawano, Tatsuya*; Tanimori, Toru*; Matsuoka, Yoshihiro*; et al.

no journal, , 

We have developed the ETCC for new medical imaging device and succeeded in imaging the some medical imaging reagents. Thus, this detector is thought promising for a new medical imaging. The F-18 point-like and rod-like phantoms are measured with new ETCC, and the imaging performance was estimated. In addition, measurement of Tc-95m which is produced by Japan Atomic Energy Agency was performed.

Oral presentation

Application of Electron Tracking Compton Camera (ETCC) in medical imaging

Sonoda, Shinya*; Nabeya, Akira*; Kimura, Hiroyuki*; Kabuki, Shigeto*; Takada, Atsushi*; Kubo, Hidetoshi*; Komura, Shotaro*; Tanimori, Toru*; Matsuoka, Yoshihiro*; Mizumura, Yoshitaka*; et al.

no journal, , 

SPECT and PET are widely used for medical imaging. However, radio isotopes available for SPECT and PET are limited. Under these circumstances, it is expected the appearance of the new $$gamma$$ imaging detector which can measure more various kinds of $$gamma$$-ray sources in order to develop new biomarkers using new radio isotopes. We set out to contribute to medical imaging technology by developing Electron-Tracking Compton Camera (ETCC) which can measure the various radioactive medicine.

Oral presentation

Application of Electron Tracking Compton Camera (ETCC) in medical imaging

Sonoda, Shinya*; Nabetani, Akira*; Kimura, Hiroyuki*; Kabuki, Shigeto*; Takada, Atsushi*; Kubo, Hidetoshi*; Komura, Shotaro*; Sawano, Tatsuya*; Tanimori, Toru*; Matsuoka, Yoshihiro*; et al.

no journal, , 

We present the performance results using this new ETCC such as the imaging test using F-18 in point-like and rod-like phantoms with varying the intense of radiation. In addition, the measurementof Tc-95m which is produced by Japan Atomic Energy Agency was performed. Tc-95m emitsthe $$gamma$$-rays with the energy, 204, 583, and 835 keV, and then an image with multi-energies is examined. The position resolution achieves less than about 8 degrees from 10 degrees at 511 keV by this improvement. Further improvement of the angular resolution (position resolution) will be presented until 2015 spring. Also, we are developing the next ETCC by increasing the thickness of the scintillator from 1 rad. to 2 rad. and the gas pressure from 1 atm to 3 atm which improvethe detection efficiency by a factor of $$>$$ 5 at 511 keV. By these improvements, the imaging time of mouse is expected to be reduced from several hours with to $$<$$20 minutes for lots of kinds of RIs with the energy band from 0.1-2 MeV.

Oral presentation

Production of $$^{95m}$$Tc for Compton camera imaging

Hatsukawa, Yuichi; Tsukada, Kazuaki; Hashimoto, Kazuyuki; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Nagai, Yasuki; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.

no journal, , 

In recent years, the Compton camera which is originally developed for the astrophysical studies was applied for medical diagnostic usage. For the Compton camera imaging require technetium isotopes emitting higher energy $$gamma$$-rays. Two Tc isotopes, $$^{95m}$$Tc (T$$_{1/2}$$ = 60 d; E$$gamma$$ = 204, 582 and 835 keV) and $$^{96}$$Tc(T$$_{1/2}$$ = 4.28 d, E$$gamma$$ = 778 and 812 keV) are candidates for Compton camera imaging. Compton camera imaging can realize high position resolution without collimator. Because of no collimator using, the Compton camera makes higher $$gamma$$-ray detection efficiency. Compared with SPECT with $$^{99m}$$Tc, the Compton camera imaging technique can be expected that radiation exposure deduce to 1/5-1/10. In this study, technetium-95m was produced by the $$^{95}$$Mo(p,n)$$^{95m}$$Tc reaction.

27 (Records 1-20 displayed on this page)