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Journal Articles

The New 300 kV multi-element AMS system at the TONO Geoscience Center, Japan Atomic Energy Agency

Fujita, Natsuko; Miyake, Masayasu*; Matsubara, Akihiro; Kokubu, Yoko; Klein, M.*; Scognamiglio, G.*; Mous, D. J. W.*; Columna, E. L.*; Shimada, Akiomi; Ishimaru, Tsuneari

Nuclear Instruments and Methods in Physics Research B, 533, p.91 - 95, 2022/12

In the Tono Geoscience Center, Japan Atomic Energy Agency, investigation of deep underground environments for R&D program related to the geological disposal of High-Level Radioactive Waste has been performed by using various dating systems including an AMS system. In response to the increasing demand for our AMS measurements especially from a newly established R&D program supporting development of technology for geological disposal of HLW, a state-of-the-art multi-nuclide AMS system was installed. This system is equipped with a 300 kV AMS. The system has capability to measure four nuclides: carbon-14, beryllium-10, aluminium-26 and iodine-129. The system structure and features, as well as the results of performance test will be presented.

Journal Articles

A Safer preprocessing system for analyzing dissolved organic radiocarbon in seawater

Otosaka, Shigeyoshi*; Jeon, H.*; Hou, Y.*; Watanabe, Takahiro; Aze, Takahiro*; Miyairi, Yosuke*; Yokoyama, Yusuke*; Ogawa, Hiroshi*

Nuclear Instruments and Methods in Physics Research B, 527, p.1 - 6, 2022/09

 Times Cited Count:0 Percentile:0.03(Instruments & Instrumentation)

The measurement the radiocarbon of dissolved organic matter (DO$$^{14}$$C) in seawater can provide information about a timescale of the dynamics of dissolved organic matter as well as about its sources in the ocean. Due to the low DOC concentration in seawater, in spite of the development of accelerator mass spectrometry, a relatively large volume of seawater ($$sim$$1 L) is required for that analysis. In addition, complicated processing such as UV irradiation that emits high heat is required. In this study, we have developed a safer and easier method to analyze DO$$^{14}$$C in seawater than the conventional method. A particularly significant change was the adoption of a low-pressure mercury lamp in the decomposition system, which enabled direct decomposition of organic matter at lower temperatures. We also propose a method to quantitatively evaluate the accuracy of this system by analyzing simulated seawater consists of a soluble reference material of organic matter and sodium chloride. This method is expected to be applied not only to carbon isotope ratio analysis but also to analysis of trace elements and isotopes of various dissolved organic substances.

Journal Articles

Measurement of nuclide production cross sections for proton-induced reactions on $$^{rm nat}$$Ni and $$^{rm nat}$$Zr at 0.4, 1.3, 2.2, and 3.0 GeV

Takeshita, Hayato*; Meigo, Shinichiro; Matsuda, Hiroki*; Iwamoto, Hiroki; Nakano, Keita; Watanabe, Yukinobu*; Maekawa, Fujio

Nuclear Instruments and Methods in Physics Research B, 527, p.17 - 27, 2022/09

 Times Cited Count:0

To improve accuracy of nuclear design of accelerator driven nuclear transmutation systems and so on, nuclide production cross sections on Ni and Zr were measured for GeV energy protons. The measured results were compared with PHITS calculations, JENDL/HE-2007 and so on.

Journal Articles

EXAFS studies for atomic structural change induced by ion irradiation of a reactor pressure vessel steel

Iwata, Keiko; Takamizawa, Hisashi; Ha, Yoosung; Shimodaira, Masaki; Okamoto, Yoshihiro; Honda, Mitsunori; Katsuyama, Jinya; Nishiyama, Yutaka

Nuclear Instruments and Methods in Physics Research B, 511, p.143 - 152, 2022/01

 Times Cited Count:0 Percentile:0.03(Instruments & Instrumentation)

Journal Articles

Measurement of nuclide production cross sections for proton-induced reactions on Mn and Co at 1.3, 2.2, and 3.0 GeV

Takeshita, Hayato*; Meigo, Shinichiro; Matsuda, Hiroki*; Iwamoto, Hiroki; Nakano, Keita; Watanabe, Yukinobu*; Maekawa, Fujio

Nuclear Instruments and Methods in Physics Research B, 511, p.30 - 41, 2022/01

 Times Cited Count:1 Percentile:0.02(Instruments & Instrumentation)

Nuclide production cross sections for proton-induced reactions on Mn and Co at incident energies of 1.3, 2.2, and 3.0 GeV were measured by the activation method at the J-PARC. In total, 143 production cross sections of reaction products were obtained. Among them, the cross sections of $$^{55}$$Mn(p,X)$$^{38}$$S and $$^{55}$$Mn(p,X)$$^{41}$$Ar were measured for the first time. The stable proton beam and well established beam monitoring system contributed to the reduction of the systematic uncertainties to typically less than 5%, which was better than those of the previous data. To examine the prediction capabilities of spallation reaction models and evaluated data library, the measured data were compared with the spallation reaction models in PHITS (INCL4.6/GEM, etc.), INCL++/ABLA07, and the JENDL/HE-2007 library. The comparison of the mean square deviation factors indicated that both INCL4.6/GEM and JENDL/HE-2007 showed better agreement with the measured data than the others.

Journal Articles

Modernization of the DCHAIN-PHITS activation code with new features and updated data libraries

Ratliff, H.; Matsuda, Norihiro; Abe, Shinichiro; Miura, Takamitsu*; Furuta, Takuya; Iwamoto, Yosuke; Sato, Tatsuhiko

Nuclear Instruments and Methods in Physics Research B, 484, p.29 - 41, 2020/12

 Times Cited Count:4 Percentile:62.16(Instruments & Instrumentation)

Journal Articles

Optimization of a 9 MeV electron accelerator bremsstrahlung flux for photofission-based assay techniques using PHITS and MCNP6 Monte Carlo codes

Meleshenkovskii, I.*; Ogawa, Tatsuhiko; Sari, A.*; Carrel, F.*; Boudergui, K.*

Nuclear Instruments and Methods in Physics Research B, 483, p.5 - 14, 2020/11

 Times Cited Count:1 Percentile:19.62(Instruments & Instrumentation)

For the purpose of fissile material detection, the technique to observe neutrons ejected from photo-fission induced by bremsstrahlung X-rays is being developed. This technique is advantageous in the sense that the machine can be compact compared to conventional neutron generators. However, photo-fission reaction cross sections are generally smaller than those of neutron-induced fission cross sections therefore optimization of the beam line is of high importance. In this study, we investigated the factors necessary to be optimized by using Monte-Carlo transport codes MCNP and PHITS. It was found that high-Z materials are advantageous to effectively produce bremsstrahlung X-rays but photons produce neutrons by secondary ($$gamma$$,n) reactions resulting in mixing of prompt and delayed fission reactions. Moreover, secondary neutrons are produced not only inside the target but also in the materials surrounding the target. Therefore it is necessary to select elements whose neutron separation energy is high to suppress parasitic secondary neutrons.

Journal Articles

Measurement of thick target neutron yield at 180$$^{circ}$$ for a mercury target induced by 3-GeV protons

Matsuda, Hiroki; Iwamoto, Hiroki; Meigo, Shinichiro; Takeshita, Hayato*; Maekawa, Fujio

Nuclear Instruments and Methods in Physics Research B, 483, p.33 - 40, 2020/11

 Times Cited Count:1 Percentile:19.62(Instruments & Instrumentation)

A thick target neutron yield for a mercury target at an angle of 180$$^{circ}$$ from the incident beam direction is measured with the time-of-flight method using a 3-GeV proton beam at the Japan Proton Accelerator Research Complex (J-PARC). Comparing the experimental result with a Monte Carlo particle transport simulation by the Particle and Heavy Ion Transport code System (PHITS) shows that there are apparent discrepancies. We find that this trend is consistent with an experimental result of neutron-induced re- action rates obtained using indium and niobium activation foils. Comparing proton-induced neutron-production double-differential cross-sections for a lead target at backward directions between the PHITS calculation and experimental data suggests that the dis- crepancies for our experiments would be linked to the neutron production calculation around 3 GeV by the PHITS spallation model and/or the calculation of nonelastic cross-sections around 3 GeV in the particle transport simulation.

Journal Articles

Microscopic analyses on Zr adsorbed IDA chelating resin by PIXE and EXAFS

Arai, Yoichi; Watanabe, So; Ono, Shimpei; Nomura, Kazunori; Nakamura, Fumiya*; Arai, Tsuyoshi*; Seko, Noriaki*; Hoshina, Hiroyuki*; Hagura, Naoto*; Kubota, Toshio*

Nuclear Instruments and Methods in Physics Research B, 477, p.54 - 59, 2020/08

 Times Cited Count:1 Percentile:19.62(Instruments & Instrumentation)

Journal Articles

Structural characterization of Eu-HONTA complexes by IBIL and EXAFS analyses

Watanabe, So; Sano, Yuichi; Okada, Makoto*; Matsuura, Haruaki*; Hagura, Naoto*; Kada, Wataru*

Nuclear Instruments and Methods in Physics Research B, 477, p.60 - 65, 2020/08

 Times Cited Count:1 Percentile:19.62(Instruments & Instrumentation)

IBIL and EXAFS analyses were applied on strucutral analysis of Eu complex formed in adsorbent developed for extraction chromatography. Those analyses revealed slight structural difference between adsorbent and solvent systems.

Journal Articles

Swift heavy ion irradiation to non-amorphizable CaF$$_{2}$$ and amorphizable Y$$_{3}$$Al$$_{5}$$O$$_{12}$$ (YAG) crystals

Amekura, Hiroshi*; Li, R.*; Okubo, Nariaki; Ishikawa, Norito; Chen, F.*

Nuclear Instruments and Methods in Physics Research B, 474, p.78 - 82, 2020/07

 Times Cited Count:4 Percentile:51.02(Instruments & Instrumentation)

Yttrium-aluminum-garnet (YAG) and calcium fluoride (CaF$$_{2}$$) were irradiated with 200 MeV Xe ions. YAG crystal was transformed to an amorphous phase, whereas CaF$$_{2}$$ shows the non-amorphizable nature. In spite of amorphization, YAG maintained its transparency, whereas CaF$$_{2}$$ markedly loses it transparency showing a broad absorption band centered at 550 nm.

Journal Articles

A Novel asymmetrical peak broadening feature for a CdZnTe detector response function modeling using PHITS particle and heavy ion transport simulation code

Meleshenkovskii, I.*; Ogawa, Tatsuhiko; Pauly, N.*; Labeau, P.-E.*

Nuclear Instruments and Methods in Physics Research B, 467, p.108 - 113, 2020/03

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

CdZnTe (CZT) semiconductor detectors are featured by the fact that it can be operated in room-temperature. In CZT, however, the hole collection efficiency is substantially less than 100% owing to its low hole-mobility. Therefore the detector signal is suppressed depending on the distance of ionization from the anode. In particular, gamma-rays interact with the detector at random, which result in asymmetric pulse-height distribution. Among the radiation transport codes available up to now, other than PHITS which can consider symmetric gaussian distribution, any codes did not have functions to consider arbitrary response functions. On the other hand, Melechankovski et al proposed a function form that can reproduce the pulse-height spectrum of CZT detectors. In this study, the pulse-height spectra of a 500 mm$$^3$$ CZT detector exposed to gamma rays from 59 keV ($$^{241}$$Am) to 1332 keV ($$^{60}$$Co) was measured and compared with the energy deposition spectrum calculated PHITS with incorporating the Melechankovski's CZT detector response formula. The comparison showed satisfactory agreement between the calculated and measured pulse-height distribution featured by the gaussian peak shape and exponential decline in the lower energy side. This new function enables experimental design considering realistic detector performance as well as detector system design considering detector response. The arbitrary detector response function was incorporated to PHITS Ver.3.10 and later.

Journal Articles

In-source laser spectroscopy of dysprosium isotopes at the ISOLDE-RILIS

Chrysalidis, K.*; Barzakh, A. E.*; Ahmed, R.*; Andreyev, A. N.; Ballof, J.*; Cubiss, J. G.*; Fedorov, D. V.*; Fedosseev, V. N.*; Fraile, L. M.*; Harding, R. D.*; et al.

Nuclear Instruments and Methods in Physics Research B, 463, p.472 - 475, 2020/01

 Times Cited Count:2 Percentile:37.33(Instruments & Instrumentation)

A number of radiogenically produced dysprosium isotopes have been studied by in-source laser spectroscopy at ISOLDE using the Resonance Ionization Laser Ion Source (RILIS). Isotope shifts were measured relative to $$^{152}$$Dy in the $$4f^{10}6s^{2}~^{5}I_{8}$$ (gs) $$rightarrow$$ $$4f^{10}6s6p~(8,1)^{0}_{8}$$ (418.8 nm $$_{rm VAC}$$)resonance transition. The electronic factor, $$F$$, and mass shift factor, M, were extracted and used for determining the changes in mean-squared charge radii for $$^{rm 145m}$$Dy and $$^{rm 147m}$$Dy for the first time.

Journal Articles

Depth profiles of energy deposition near incident surface irradiated with swift heavy ions

Ogawa, Tatsuhiko; Ishikawa, Norito; Kai, Takeshi

Nuclear Instruments and Methods in Physics Research B, 461, p.272 - 275, 2019/12

 Times Cited Count:5 Percentile:61.87(Instruments & Instrumentation)

Heavy ion irradiation, which deposits energy locally in materials, is widely used to study new material modification and radiation-induced damage. So far, radial distribution of energy deposition by heavy ions were well studied. By contrast, depth profile of energy deposition was usually assumed to be uniform but the energy deposition near the incident surface is likely suppressed because the delta-rays are pushed by the incident heavy ions. In this study, spatial distribution of energy deposition in the materials exposed to heavy ions is calculated by using a track structure simulation code RITRACKS. The result showed that energy deposition is suppressed in the first 2 nm of water and that beyond 2 nm is uniform. This result can be applied to the materials other than water by scaling with electron density. It is indicated that reactor fuel pins damaged by fission products and the materials modified by heavy ions receive less energy deposition and less radiation effect in the first 2 nm.

Journal Articles

Control of the size of etchable ion tracks in PVDF; Irradiation in an oxygen atmosphere and with fullerene C$$_{60}$$

Kitamura, Akane; Yamaki, Tetsuya*; Yuri, Yosuke*; Koshikawa, Hiroshi*; Sawada, Shinichi*; Yuyama, Takahiro*; Usui, Aya; Chiba, Atsuya*

Nuclear Instruments and Methods in Physics Research B, 460, p.254 - 258, 2019/12

 Times Cited Count:2 Percentile:29.45(Instruments & Instrumentation)

Poly(vinylidene-fluoride) (PVDF) film is suitable for investigation of the size of etchable ion tracks because we can clearly judge the finish of the track etching and the surrounding bulk area remains due to the high chemical stability. Thereby we can measure the radius of ion tracks of each ion. In this study, we focused on two irradiation conditions for controlling the size of etchable ion tracks of PVDF films. One was irradiation in an oxygen atmosphere and the other was a fullerene (C$$_{60}$$$$^{+}$$) cluster beam irradiation. SEM observation showed that the size of pores became larger by irradiation in an oxygen atmosphere. It was found that the oxidation of ion tracks widened the size of etchable ion tracks. The C$$_{60}$$$$^{+}$$ irradiation caused larger etchable tracks on the PVDF surface. The result could represent the effect of local and simultaneous collisions by the swift aggregated ions.

Journal Articles

FE-SEM observation of chains of nanohillocks in SrTiO$$_{3}$$ and Nb-doped SrTiO$$_{3}$$ surfaces irradiated with swift heavy ions

Kitamura, Akane; Ishikawa, Norito; Kondo, Keietsu; Yamamoto, Shunya*; Yamaki, Tetsuya*

Nuclear Instruments and Methods in Physics Research B, 460, p.175 - 179, 2019/12

 Times Cited Count:3 Percentile:42.08(Instruments & Instrumentation)

Irradiation at grazing incidence formed chains of multiple hillocks on the surface of strontium titanate (SrTiO$$_{3}$$) and titanium oxide (TiO$$_{2}$$). They were observed with an atomic force microscope (AFM), however, the AFM measurement gives resolution errors in a nanometer order due to the curvature of the probe tip. To prevent these errors, a field emission scanning electron microscope (FE-SEM) would be a better option for observation. In this study, we performed SEM observations for the chains of the multiple hillocks. Single crystals of SrTiO$$_{3}$$ and TiO$$_{2}$$ were irradiated with 200 MeV $$^{136}$$Xe$$^{14+}$$ in the tandem accelerator at JAEA-Tokai. It was revealed that a lot of isolated hillocks were formed in a line on these surface. The diameter and the interval of those hillocks are discussed in comparison to AFM observation.

Journal Articles

Ion-induced irradiation hardening of the weld heat-affected zone in low alloy steel

Ha, Yoosung; Takamizawa, Hisashi; Katsuyama, Jinya; Hanawa, Satoshi; Nishiyama, Yutaka

Nuclear Instruments and Methods in Physics Research B, 461, p.276 - 282, 2019/12

 Times Cited Count:1 Percentile:16.18(Instruments & Instrumentation)

Journal Articles

Current status of JAEA-AMS-TONO in the 20th year

Kokubu, Yoko; Fujita, Natsuko; Miyake, Masayasu; Watanabe, Takahiro; Ishizaka, Chika; Okabe, Nobuaki; Ishimaru, Tsuneari; Matsubara, Akihiro*; Nishizawa, Akimitsu*; Nishio, Tomohiro*; et al.

Nuclear Instruments and Methods in Physics Research B, 456, p.271 - 275, 2019/10

 Times Cited Count:1 Percentile:16.18(Instruments & Instrumentation)

JAEA-AMS-TONO has been in operation at the Tono Geoscience Center, Japan Atomic Energy Agency since 1998 and 20 years have passed from the beginning of its utilization. The AMS system is a versatile system based on a 5 MV tandem Pelletron type accelerator. The system has been used to measure carbon-14 ($$^{14}$$C), beryllium-10 ($$^{10}$$Be) and aluminium-26 ($$^{26}$$Al). In addition, the development of measurement of iodine-129 ($$^{129}$$I) has been started. The main use is measurement of $$^{14}$$C in geological samples for dating studies in neotectonics and hydrogeology. In order to increase the speed of sample preparation, we introduced the automated graphitization equipment and made a gas-strip line to collect dissolved inorganic carbon in groundwater samples. Measurement of $$^{10}$$Be and $$^{26}$$Al has been used for geoscience studies and the detection limit in the measurement of $$^{10}$$Be was improved by $$^{7}$$Be-counting suppression. Recently tuning of measurement condition of $$^{129}$$I has been progressed.

Journal Articles

Ion beam induced luminescence of complexes formed in adsorbent for MA recovery process

Watanabe, So; Katai, Yuya*; Matsuura, Haruaki*; Kada, Wataru*; Koka, Masashi*; Sato, Takahiro*; Arai, Tsuyoshi*

Nuclear Instruments and Methods in Physics Research B, 450, p.61 - 65, 2019/07

 Times Cited Count:1 Percentile:16.18(Instruments & Instrumentation)

Journal Articles

Thick target neutron yields from 100- and 230-MeV/nucleon helium ions bombarding water, PMMA, and iron

Tsai, P.-E.; Heilbronn, L. H.*; Lai, B.-L.*; Iwata, Yoshiyuki*; Murakami, Takeshi*; Sheu, R.-J.*

Nuclear Instruments and Methods in Physics Research B, 449, p.62 - 70, 2019/06

 Times Cited Count:3 Percentile:42.08(Instruments & Instrumentation)

The secondary neutrons produced from 100- and 230-MeV/nucleon He ions, respectively, stopping in the thick iron, PMMA and water targets are measured by the time of flight method combined with the pulse shape discrimination of liquid scintillators. The experimental data show that the secondary neutrons were contributed from breakup of projectiles, emission from overlap regions of projectile nuclei and target nuclei, and evaporation of projectiles and target nuclei. The measured double-differential thick target neutron yields, angular distributions, and total neutron yields per ion, were benchmarked by the PHITS, FLUKA, and MCNP model calculations. The default models in these codes agree the experimental data well at intermediate-to-large angles in the low-to-intermediate energy range. However, the physics models implemented in PHITS need further improvement for some particular nuclear interaction mechanisms, and this work can be an importance reference for future model development.

449 (Records 1-20 displayed on this page)