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Journal Articles

Estimated isotopic compositions of Yb in enriched $$^{176}$$Yb for producing $$^{177}$$Lu with high radionuclide purity by $$^{176}$$Yb($$d,x$$)$$^{177}$$Lu

Nagai, Yasuki*; Kawabata, Masako*; Hashimoto, Shintaro; Tsukada, Kazuaki; Hashimoto, Kazuyuki*; Motoishi, Shoji*; Saeki, Hideya*; Motomura, Arata*; Minato, Futoshi; Ito, Masatoshi*

Journal of the Physical Society of Japan, 91(4), p.044201_1 - 044201_10, 2022/04

 Times Cited Count:0 Percentile:48.58(Physics, Multidisciplinary)

Recently, $$^{177}$$Lu is considered as one of the most important medical RIs for treating neuroendocrine tumors. A plan to produce $$^{177}$$Lu with high purity by using enriched $$^{176}$$Yb samples with irradiation of deuteron beams in accelerators has been discussed. However, since the other Yb isotopes contained in the Yb sample interacts with deuterons, Lu isotopes other than $$^{177}$$Lu are produced as impurities. Since the purity of $$^{177}$$Lu is important for medical use, a method to evaluate the impurity of Lu has been required. In this study, we proposed a new method to estimate production yields of each Lu isotopes in Yb samples with arbitrary isotopic compositions by using excitation functions of Yb($$d,x$$)Lu reactions and the particle transport calculation code PHITS. The method plays an important role in discussing the isotopic composition of enriched samples to produce high-purity $$^{177}$$Lu using accelerators.

Journal Articles

Large scale production of $$^{64}$$Cu and $$^{67}$$Cu via the $$^{64}$$Zn(n, p)$$^{64}$$Cu and $$^{68}$$Zn(n, np/d)$$^{67}$$Cu reactions using accelerator neutrons

Kawabata, Masako*; Motoishi, Shoji*; Ota, Akio*; Motomura, Arata*; Saeki, Hideya*; Tsukada, Kazuaki; Hashimoto, Shintaro; Iwamoto, Nobuyuki; Nagai, Yasuki*; Hashimoto, Kazuyuki*

Journal of Radioanalytical and Nuclear Chemistry, 330(3), p.913 - 922, 2021/12

 Times Cited Count:4 Percentile:73.26(Chemistry, Analytical)

Both $$^{64}$$Cu and $$^{67}$$Cu are promising radionuclides in nuclear medicine. Production yields of these radionuclides were quantified by irradiating 55.4 g of natural zinc with accelerator neutrons. Clinically suitable $$^{64}$$Cu and $$^{67}$$Cu yields were estimated by experimental based numerical simulations using 100 g of enriched $$^{64}$$Zn and $$^{68}$$Zn, respectively, and elevated neutron fluxes from 40 MeV, 2 mA deuterons. A combined thermal- and resin-separation method was developed to isolate $$^{64}$$Cu and $$^{67}$$Cu from zinc, resulting in 73% separation efficiency and 97% zinc recovery. Such methods can provide large scale production of $$^{64}$$Cu and $$^{67}$$Cu for clinical applications.

Journal Articles

Anomalous radioisotope production for $$^{68}$$ZnO using polyethylene by accelerator neutrons

Tsukada, Kazuaki; Nagai, Yasuki*; Hashimoto, Shintaro; Minato, Futoshi; Kawabata, Masako*; Hatsukawa, Yuichi*; Hashimoto, Kazuyuki*; Watanabe, Satoshi*; Saeki, Hideya*; Motoishi, Shoji*

Journal of the Physical Society of Japan, 89(3), p.034201_1 - 034201_7, 2020/03

 Times Cited Count:2 Percentile:22.58(Physics, Multidisciplinary)

We found anomalously large yields of $$^{67}$$Ga, $$^{66}$$Ga, $$^{rm 69m}$$Zn and $$^{64}$$Cu by neutron irradiation on a $$^{68}$$ZnO sample in a polyethylene shield. Neutron beams are generated from the $$^{9}$$Be($$d,n$$) reaction for 50 MeV deuterons. The yields obtained were more than 20 times larger than those in the unshielded sample. On the other hand, the yields of $$^{67}$$Ga, $$^{66}$$Ga, $$^{rm 69m}$$Zn and $$^{64}$$Cu from a metallic $$^{68}$$Zn sample and the yields of $$^{67}$$Cu, $$^{65}$$Ni and $$^{65}$$Zn from the $$^{68}$$ZnO and $$^{68}$$Zn samples were almost insensitive to the shield conditions. This finding would provide us a unique capability of accelerator neutrons to simultaneously produce a large amount of several radioisotopes, including proton induced reaction products, by using a single sample. The experimental data were compared with the yields estimated by using the Particle and Heavy Ion Transport code System and the result was discussed.

Journal Articles

$$^{99}$$Mo yield using large sample mass of MoO$$_{3}$$ for sustainable production of $$^{99}$$Mo

Tsukada, Kazuaki; Nagai, Yasuki*; Hashimoto, Kazuyuki*; Kawabata, Masako*; Minato, Futoshi; Saeki, Hideya*; Motoishi, Shoji*; Ito, Masatoshi*

Journal of the Physical Society of Japan, 87(4), p.043201_1 - 043201_5, 2018/04

 Times Cited Count:9 Percentile:60.59(Physics, Multidisciplinary)

Journal Articles

Measurement and estimation of the $$^{99}$$Mo production yield by $$^{100}$$Mo($$n,2n$$)$$^{99}$$Mo

Minato, Futoshi; Tsukada, Kazuaki; Sato, Nozomi*; Watanabe, Satoshi*; Saeki, Hideya*; Kawabata, Masako*; Hashimoto, Shintaro; Nagai, Yasuki*

Journal of the Physical Society of Japan, 86(11), p.114803_1 - 114803_6, 2017/11

 Times Cited Count:8 Percentile:57.21(Physics, Multidisciplinary)

We have measured the yield of $$^{99}$$Mo, the mother nuclide of $$^{99m}$$Tc used in nuclear diagnostic procedure. $$^{99}$$Mo was produced by $$^{100}$$Mo($$n$$,$$2n$$)$$^{99}$$Mo using neutrons with thermal energy up to about 40 MeV, provided by C($$d$$,$$n$$). The $$^{99}$$Mo yield agrees with an estimated yield with the use of the latest data of C($$d$$,$$n$$) and the evaluated cross section given in the JENDL. Based on this, a new calculation was carried out to produce $$^{99}$$Mo to seek for a good economical condition. Various conditions such as the $$^{100}$$MoO$$_{3}$$ sample mass, the distance between the carbon target and the sample, the radius of the deuteron beam, and the neutron irradiation time were considered. The calculated $$^{99}$$Mo yield indicates that about 30% of the $$^{99}$$Mo demand in Japan can be fulfilled with a single accelerator. The elusion of $$^{99m}$$Tc from the $$^{99}$$Mo twice per day would meet about 50% of the $$^{99}$$Mo demand.

Journal Articles

Application of $$^{67}$$Cu produced by $$^{68}$$Zn($$n,n'p+d$$)$$^{67}$$Cu to biodistribution study in tumor-bearing mice

Sugo, Yumi*; Hashimoto, Kazuyuki*; Kawabata, Masako*; Saeki, Hideya*; Sato, Shunichi*; Tsukada, Kazuaki; Nagai, Yasuki*

Journal of the Physical Society of Japan, 86(2), p.023201_1 - 023201_3, 2017/02

 Times Cited Count:13 Percentile:68.41(Physics, Multidisciplinary)

$$^{67}$$Cu produced by the $$^{68}$$Zn($$n,n'p+d$$)$$^{67}$$Cu reaction was used for the first time to determine the biodistribution of $$^{67}$$CuCl$$_{2}$$ in colorectal tumor-bearing mice. High uptake of $$^{67}$$Cu was observed in the tumor as well as in the liver and kidney which are the major organs for copper metabolism. The result showing $$^{67}$$Cu accumulation in the tumor suggests that $$^{67}$$CuCl$$_{2}$$ can be a potential radionuclide agent for cancer radiotherapy. It would also encourage further studies on the therapeutic effect in small animals using an increased dose of $$^{67}$$Cu produced by the $$^{68}$$Zn($$n,n'p+d$$)$$^{67}$$Cu reaction using intense neutrons available at present.

Journal Articles

SPECT imaging of mice with $$^{99m}$$Tc-radiopharmaceuticals obtained from $$^{99}$$Mo produced by $$^{100}$$Mo(n,2n)$$^{99}$$Mo and fission of $$^{235}$$U

Hashimoto, Kazuyuki; Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi*; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji*; Ota, Masayuki; Konno, Chikara; Ochiai, Kentaro; et al.

Journal of the Physical Society of Japan, 84(4), p.043202_1 - 043202_4, 2015/04

 Times Cited Count:7 Percentile:53.16(Physics, Multidisciplinary)

Journal Articles

New phenomenon observed in thermal release of $$^{99m}$$Tc from molten $$^{100}$$MoO$$_{3}$$

Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji*; Sato, Nozomi*; Ota, Akio*; Shiina, Takayuki*; Kawauchi, Yukimasa*

Journal of the Physical Society of Japan, 84(2), p.023201_1 - 023201_4, 2015/02

 Times Cited Count:6 Percentile:45.45(Physics, Multidisciplinary)

$$^{99m}$$Tc for medical use can be separated by thermochromatography from a molten $$^{99}$$MoO$$_{3}$$ sample. Effect of moist oxygen gas on the $$^{99m}$$Tc release from molten $$^{99}$$MoO$$_{3}$$ samples was investigated using a $$^{99}$$Mo/$$^{99m}$$Tc generator. $$^{99}$$Mo was produced with $$^{100}$$Mo(n,2n)$$^{99}$$Mo. A new phenomenon has been observed: release rate, separation- and recovery-efficiencies of $$^{99m}$$Tc were higher in the moist oxygen gas than those in the dry oxygen gas. The present result is a significant progress towards the stable production of a high quality $$^{99m}$$Tc from a molten MoO$$_{3}$$ sample with high separation efficiency. The result would also give us a new insight into the interaction between the moist oxygen gas and the molten MoO$$_{3}$$.

Journal Articles

First measurement of the radionuclide purity of the therapeutic isotope $$^{67}$$Cu produced by $$^{68}$$Z($$n$$,$$x$$) reaction using $$^{rm nat}$$C($$d$$,$$n$$) neutrons

Sato, Nozomi; Tsukada, Kazuaki; Watanabe, Satoshi; Ishioka, Noriko; Kawabata, Masako; Saeki, Hideya; Nagai, Yasuki; Kin, Tadahiro*; Minato, Futoshi; Iwamoto, Nobuyuki; et al.

Journal of the Physical Society of Japan, 83(7), p.073201_1 - 073201_4, 2014/07

 Times Cited Count:13 Percentile:64.28(Physics, Multidisciplinary)

We have for the first time demonstrated that the therapeutic nuclide of $$^{67}$$Cu produced by $$^{68}$$Zn($$n$$,$$x$$)$$^{67}$$Cu has highest radionuclide purity compared to previous ones. We measured a $$gamma$$-ray spectrum of the reaction product produced by bombarding an enriched $$^{68}$$Zn sample with neutrons with a HPGe detector. The neutrons were obtained by $$^{rm nat}$$C($$d$$,$$n$$) using 41 MeV deuterons provided from Takasaki Ion Accelerators for Advanced Radiation Application of Japan Atomic Energy Agency. Relative production yields of impurity radionuclides such as $$^{65}$$Zn to $$^{67}$$Cu are extremely low, which allow us to chemically separate $$^{67}$$Cu from an irradiated $$^{68}$$Zn sample with a few steps and to reuse high cost an enriched $$^{68}$$Zn sample. The present result strongly suggest that the $$^{68}$$Zn($$n$$,$$x$$)$$^{67}$$Cu reaction is the most promising route to produce high quality $$^{67}$$Cu and could solve a longstanding problem of establishing an appropriate production method of $$^{67}$$Cu.

Journal Articles

High thermo-separation efficiency of $$^{99m}$$Tc from molten $$^{100}$$MoO$$_{3}$$ samples by repeated milking tests

Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji*

Journal of the Physical Society of Japan, 83(8), p.083201_1 - 083201_4, 2014/07

 Times Cited Count:10 Percentile:58.02(Physics, Multidisciplinary)

Journal Articles

Generation of radioisotopes with accelerator neutrons by deuterons

Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Sonoda, Nozomi; Kawabata, Masako; Harada, Hideo; Kin, Tadahiro*; Tsukada, Kazuaki; et al.

Journal of the Physical Society of Japan, 82(6), p.064201_1 - 064201_7, 2013/06

 Times Cited Count:41 Percentile:85.16(Physics, Multidisciplinary)

JAEA Reports

Measurement of tritium activity in the aluminum pipe of JRR-2 heavy water primary cooling system using imaging plate

Motoishi, Shoji; Kobayashi, Katsutoshi; Saeki, Hideya*

JAERI-Tech 2000-070, 34 Pages, 2000/12

JAERI-Tech-2000-070.pdf:5.19MB

no abstracts in English

Oral presentation

Concentration of $$^{188}$$Re solutions from alumina-based $$^{188}$$W/$$^{188}$$Re generator

Hashimoto, Kazuyuki; Motoishi, Shoji; Saeki, Hideya*; Sorita, Takami; Matsuoka, Hiromitsu

no journal, , 

no abstracts in English

Oral presentation

Development of an apparatus to concentrate $$^{188}$$Re solutions by a multi column system for cancer therapeutic experiments

Hashimoto, Kazuyuki; Motoishi, Shoji*; Saeki, Hideya*; Sorita, Takami; Matsuoka, Hiromitsu

no journal, , 

Rhenium-188 is a useful generator-produced radioisotope for therapeutic applications because of their energetic beta particles and $$gamma$$ rays suitable for imaging. Because the $$^{188}$$W parent is obtained in a relatively low specific activity from the irradiation of enriched $$^{186}$$W in a reactor, relatively large volumes of normal saline are required to elute the $$^{188}$$Re from alumina based $$^{188}$$W/$$^{188}$$Re generators. In this study, a simple apparatus for effective concentrations of 188Re solutions from alumina-based $$^{188}$$W/$$^{188}$$Re generators was developed by a tandem cation-anion column system. Concentration ratios greater than 50:1 can be achieved with this apparatus.

Oral presentation

Medical radioisotope production with accelerator neutrons by 40 MeV deuterons

Tsukada, Kazuaki; Sato, Nozomi; Watanabe, Satoshi; Ishioka, Noriko; Hatsukawa, Yuichi; Hashimoto, Kazuyuki; Kin, Tadahiro*; Kawabata, Masako; Saeki, Hideya; Nagai, Yasuki

no journal, , 

no abstracts in English

Oral presentation

Production of $$^{67}$$Cu and $$^{64}$$Cu using zinc target irradiated with accelerator neutrons

Kawabata, Masako; Hashimoto, Kazuyuki; Saeki, Hideya; Sato, Nozomi*; Motoishi, Shoji*; Nagai, Yasuki

no journal, , 

no abstracts in English

Oral presentation

High quality $$^{99m}$$Tc obtained from $$^{99}$$Mo produced by $$^{100}$$Mo(n,2n) using accelerator neutrons

Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi*; Hashimoto, Kazuyuki; Saeki, Hideya; Motoishi, Shoji*; Hatsukawa, Yuichi; Ota, Akio; Shiina, Takayuki; Kawauchi, Yukimasa

no journal, , 

$$^{99m}$$Tc, the daughter nuclide of $$^{99}$$Mo, is widely used for medical diagnosis. In Japan, about 0.9 million diagnostic procedures are carried out using $$^{99m}$$Tc. $$^{99}$$Mo has been mostly produced using $$^{235}$$U in research reactors. Because of recent shortages of $$^{99}$$Mo, a variety of alternative production methods of $$^{99}$$Mo or $$^{99m}$$Tc were proposed. We proposed to produce $$^{99}$$Mo by $$^{100}$$Mo(n,2n) using neutrons from an accelerator. The route is characterized to produce a large quantity of high-quality $$^{99}$$Mo with a minimum level of radioactive wastes, since the cross section of the $$^{100}$$Mo(n,2n)$$^{99}$$Mo reaction at 11 $$<$$ En $$<$$ 18 MeV is large, and the cross sections of the (n,He), (n,n'p), and (n,p) reactions on $$^{100}$$Mo are quite small. Intense neutrons are available because of recent progresses of accelerator and target technologies. In the talk, we show our recent experimental results to obtain $$^{99m}$$Tc with high-quality using $$^{99}$$Mo produced by $$^{100}$$Mo(n,2n).

Oral presentation

Production of $$^{67}$$Cu for cancer therapy using fast neutrons from $$^{nat}$$C(d,n) reaction

Hashimoto, Kazuyuki; Kawabata, Masako; Saeki, Hideya; Tsukada, Kazuaki; Sato, Nozomi*; Motoishi, Shoji*; Nagai, Yasuki; Watanabe, Satoshi; Ishioka, Noriko

no journal, , 

Copper-67 is an attractive radionuclide for cancer therapy, because of emissions of medium energy $$beta$$ particle (a mean energy of 141 keV) and $$gamma$$ rays (91, 93, 185 keV) suitable for imaging, and its appropriate half-life (62 hours). However, the use of $$^{67}$$Cu for clinical researches has been limited due to the difficulty in obtaining sufficient quantities. In this study, we have investigated the production of $$^{67}$$Cu by the $$^{68}$$Zn(n,x)$$^{67}$$Cu reaction (x = n'p, d) using fast neutrons from $$^{nat}$$C(d,n) reaction. The highly purified $$^{67}$$Cu was obtained by the two columns separation method (chelate resin chelex-100 and anion exchange resin AG1-X8). Furthermore, the labelling of DOTA and TETA which are useful bifunctional ligands for the labelling monoclonal antibodies was succeeded in more than 97% yield.

Oral presentation

Production of $$^{67}$$Cu for cancer therapy using accelerator neutrons

Kawabata, Masako; Hashimoto, Kazuyuki; Saeki, Hideya; Tsukada, Kazuaki; Watanabe, Satoshi; Nagai, Yasuki

no journal, , 

$$^{67}$$Cu has being attracting attention as a potential candidate for radiopharmaceutical. A high-purity $$^{67}$$Cu can be isolated from an irradiated $$^{68}$$ZnO using fast neutrons generated via $$^{nat}$$C(d,n) reaction with only a few RIs as side products. This study was aimed at achieving a higher purity for the final $$^{67}$$Cu by separating $$^{65}$$Ni amongst other side products. As a result $$^{67}$$Cu free from $$^{65}$$Ni was obtained with high radionuclide purity with minimum loss of time during the separation.

Oral presentation

Production of $$^{67}$$Cu for cancer therapy using accelerator neutrons

Hashimoto, Kazuyuki; Kawabata, Masako*; Saeki, Hideya*; Sato, Shunichi*; Tsukada, Kazuaki; Watanabe, Satoshi; Nagai, Yasuki

no journal, , 

no abstracts in English

31 (Records 1-20 displayed on this page)