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Sakamoto, Masahiro; Okumura, Keisuke; Kanno, Ikuo; Matsumura, Taichi; Terashima, Kenichi; Riyana, E. S.; Kaneko, Junichi*; Mizokami, Masato*; Mizokami, Shinya*
Journal of Nuclear Science and Technology, 10 Pages, 2025/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)Harada, Hideo; Takayama, Naoki; Komeda, Masao
Journal of Physics Communications, 4(8), p.085004_1 - 085004_17, 2020/08
A new convention of epithermal neutron spectrum is formulated for improving accuracy of resonance integrals. The new type function is proposed as an approximating function of epithermal neutron spectrum based on calculations by the state-of-art Monte Carlo code MVP-3. Bias effects on determination of resonance integrals due to utilizing approximating functions of the traditional types and the new type are compared. The other bias effect is also investigated, which is caused by neglecting position dependence of a neutron spectrum inside an irradiation capsule. For demonstrating the bias effects due to these assumptions on neutron spectrum quantitatively in a practical case, the thermal neutron-capture cross section and resonance integral of 
Cs measured at a research reactor JRR-3 are re-evaluated. A superior property of the proposed new convention is discussed. The experimental method is proposed to determine the new shape factor 
introduced in the convention by a combinational use of triple flux monitors (
Au, 
Co and 
Zr), and its analytical methodology is formulated.
cross-section of long-lived fission products as part of the ImPACT ProjectHales, B. P.; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu
no journal, ,
Honda, Maki; Martschini, M.*; Lachner, J.*; Wieser, A.*; Marchhart, O.*; Steier, P.*; Golser, R.*; Sakaguchi, Aya*
no journal, ,
The effective isobar suppression system based on the interaction between accelerated ions and lasers (photons) has been introduced into conventional AMS systems, allowing an increasing number of nuclides to be measured by AMS. This presentation will give an overview of the analytical technique, the measurement results, and the remaining challenges as examples of world-leading successful AMS of 
Sr and Cs in environmental samples obtained from the IAEA and others. Moreover, the applicability of the AMS method in geoscience (e.g., studies of Sr distribution in the hydrosphere and the range of applicable environmental samples) will also be discussed.
Cs in Cs adsorbent by LA-ICP-MSAsai, Shiho*; Ohata, Masaki*; Hanzawa, Yukiko; Yomogida, Takumi; Horita, Takuma; Kitatsuji, Yoshihiro
no journal, ,
A large amount of Cs adsorbents left over after decontamination of waste water has continued to accumulate in the Fukushima Daiichi Nuclear Power Plant. For safe disposal of such Cs adsorbents, estimation of the radioactivity is crucial. A long-lived beta emitting nuclide Cs which is captured in the Cs adsorbents along with a major radiation contributor 
Cs. Different from Cs which can be measured in gamma spectrometry, the activity of Cs is generally measured in liquid form, requiring elution of Cs
. However, high radiation from the Cs adsorbents hampers the operations. In this study, we applied LA-ICP-MS which allows direct measurement of Cs adsorbent. With Cs /Cs given by LA-ICP-MS, Cs can be calculated by combining a measured Cs radioactivity. A radiocesium-containing sample was used to verify the proposed method. The results agreed well with those obtained through the measurement of Cs-separated solution.
Sr in environmental samples at the attogram-level by accelerator mass spectrometryMartschini, M.*; Honda, Maki; Merchel, S.*; Winkler, S.*; Golser, R.*
no journal, ,
The quantitative analysis of Sr is cumbersome and time-consuming because it is a pure -ray emitter. The detection limit of Sr by conventional accelerator mass spectrometry (AMS) methods is comparable to the typical detection limit of 3 mBq for -ray detection methods, mainly due to the interference of the isobaric Zr. The worldwide unique Ion Laser Interaction Mass Spectrometry (ILIAMS), performed at the University of Vienna, effectively removes Zr with a laser and reaction gases. Therefore, the detection limits of Sr is superior (
0.1 mBq) to conventional AMS systems not equipped with such an ion-laser interaction isobaric removal system. In this study, Sr analysis in coral samples etc., an environmental sample under extreme conditions (e.g. low concentrations of 
Bq/g and limited sample volumes of grams), was tried. To lower the detection limit 0.1 mBq, Sr was purified (Sr carrier) from old age coral with almost no Sr contamination from atmospheric nuclear tests, chemical separation of environmental samples were conducted, and Sr was measured by AMS. The results showed that the detection limit of Sr achieved in the analysis was 0.03 mBq (Sr/Sr 5
10
, 1/100 of the -ray detection methods). The detection limit achieved in this study corresponds to 2 ag of Sr in 1 mg of Sr target. The latest results of highly sensitive Sr analysis in small amounts of general environmental samples (coral, seawater, etc.) are mainly presented.
CsTajima, Taiyo*; Asai, Shiho*; Saito, Kyoichi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Horita, Takuma; Yamazaki, Shinya*; Takaku, Yuichi*; Sueki, Keisuke*; Sakaguchi, Aya*
no journal, ,
Cs is a radionuclide introduced into the environment by human nuclear activities. The use of Cs as an oceanic circulation tracer and the need for monitoring around nuclear facilities require the establishment of a measurement method for this nuclide. In this study, the appropriate adsorption and desorption conditions of Cs in seawater using the insoluble cobalt ferrocyanide-impregnated adsorbent synthesized by graft polymerisation were investigated. A chemical separation method of Cs for mass spectrometry was also investigated.
