Local structure analysis of light elements included in simulated radioactive waste glasses by soft X-ray absorption fine structure

Okamoto, Yoshihiro; Nagai, Takayuki; Kaneko, Koji; Motokawa, Ryuhei; Haga, Yoshinori; Yamanaka, Keisuke*; Ota, Toshiaki*

2017-Nendo Seika Kokaigata Riyo Seika Hokokusho (Ritsumeikan Daigaku SR Senta), p.33 - 36, 2018/00

The high-level radioactive waste solution which generated from a spent nuclear fuel reprocessing process are mixed with a borosilicate glass frit in a vitrification process, and a chemical stable glass solidified body is produced. To understand local structure of light elements included in a glass solidified body, we carried out a B K-edge XANES measurement of raw glass frits and simulated radioactive waste glasses. As a result of this estimation of boron local structure in glass samples, it was found that the sp type boron (BO) percentage increases and the sp type (BO) percentage by increasing the sodium content in glass frits.

Quantitative evaluation of charge state for internuclear distance of constituent ions dissociated from C ion moving in a solid

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Yamada, Keisuke; Kaneko, Toshiaki*

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 161, 2013/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2012-046.pdf

An average charge of the constituent ions resulting from the foil-induced dissociation of cluster ions is smaller than that of monatomic ions at the same speed. It is considered that such a charge reduction effect in cluster ion bombardments depend strongly on the internuclear distance between constituent ions moving in a solid. However, there are few reports in which average charges of the constituent ions had been quantitatively evaluated in terms of their internuclear distance increasing by the screened Coulomb repulsion. Therefore, we developed a method which evaluate quantitatively the average charge for internuclear distance of constituent ions in solid through the measurements of the divergence angle of the constituent ions after foil penetration. The achieved results are approximately equal to the theoretical value derived from model considering the cluster effect in average charge.

Charge state for internuclear distance of cluster constituent ions penetrating through a foil

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Yamada, Keisuke; Kaneko, Toshiaki*

Dai-25-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.98 - 101, 2012/07

Availability of the swift cluster ion is expected as new irradiation source, because the cluster ion bombardment to the solid brings irradiation effects different from the monatomic ion bombardment at the same speed. This unique effect, cluster effect, is caused via the physical processes that a number of high energy ions within a narrow spatiotemporal region make the high density excited states and that the constituent ion influences with respect to one another. For understanding of the expression mechanism of cluster effect, detailed investigation of these two physical processes are needed. In this study, with a focus on the interaction between constituent ions, we developed an analyzing method that shows quantitatively the relationship between the internuclear distance of constituent ions and their charge states, using the Coulomb explosion imaging technique, to investigate the contribution of the screened Coulomb potential to the cluster effect.

Measurement of charge states corresponding to relative position of constituent ions resulting from foil-induced dissociation of aligned C ions

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Yamada, Keisuke; Kaneko, Toshiaki*

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 151, 2012/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2011-043.pdf

In order to understand the mechanism of charge reduction in cluster ions observed in the foil-transmission experiments, we investigate contributions to charge states of the cluster constituent ions from ion-induced potential. For the C ions passing through a this foil, we found out that the charge states of tracing ions are larger than that of leading ions.

Measurement of divergence angles classified by charge-state combination of C constituents passing through a thin carbon foil

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Takahashi, Yasuyuki; Yamada, Keisuke; Kaneko, Toshiaki*

Nuclear Instruments and Methods in Physics Research B, 269(9), p.824 - 828, 2011/05

https://doi.org/10.1016/j.nimb.2010.12.002

It is necessary to clarify the relationship between the internuclear distance of the cluster constituent ions and these charge states for the elucidation of mechanism of the vicinage effects which are expressed due to the interaction with matter. Therefore the coincidence measurement between divergence angles and final charge states of the constituent ions resulting from dissociation of 6-MeV C ions in a thin carbon foil were performed. The strong dependence of the final charge state of constituent ions on the initial internuclear distance of projectile ion was quantitatively indicated by the fitting analysis of the angular distributions for various final charge-state combinations using the Monte Carlo particle trajectory simulation.

Average charge and its projectile orientation dependence of fragment ions passing through a thin foil with a swift carbon cluster

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Adachi, Masahiro; Yamada, Keisuke; Takahashi, Yasuyuki; Kaneko, Toshiaki*

JAEA-Conf 2008-012, p.84 - 86, 2009/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Conf-2008-012-1.pdf

no abstracts in English

Average charge and its structure dependence of fragment ions under irradiation of a thin carbon foil with a 1-MeV/atom C cluster ion

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Adachi, Masahiro; Kaneko, Toshiaki*

Physical Review A, 76(6), p.063201_1 - 063201_6, 2007/12

https://doi.org/10.1103/PhysRevA.76.063201

The charge states of fragment ions were measured for 1-MeV/atom C cluster ions penetrating a carbon foil of 2.4-g/cm thickness. Those ions were detected with a luminance plate detector monitored by a CCD camera. The detected ion signals were traced by coulomb explosion imaging technique, which enabled us to classify charge states of each fragment ion and spatial structure of a cluster ion on emerging from the foil. Using this technique, for the first time, we found that (1) the measured average charges of the fragment ions in a triangular structure are smaller than those in a linear-chain structure, and (2) the edge-position ions in a linear structure have the average charges greater than the middle-position ion. These experimental results are well supported by a recent theory on the cluster average charge.

Energy spectra of electrons induced by MeV atom clusters

Kudo, Hiroshi*; Iwasaki, Wataru*; Uchiyama, Rumi*; Tomita, Shigeo*; Shima, Kunihiro*; Sasa, Kimikazu*; Ishii, Satoshi*; Narumi, Kazumasa; Naramoto, Hiroshi; Saito, Yuichi; et al.

Japanese Journal of Applied Physics, Part 2, 45(22), p.L565 - L568, 2006/06

https://doi.org/10.1143/JJAP.45.L565

The first observation of the energy distribution of electrons emitted from solids bombarded by MeV atom clusters is reported. In the backward direction, using graphite and Si bombarded by C and Al (n 8), an appreciable suppression of electron emission has been observed at electron energies lower than 10 eV. Electron yield per atom decreases with increasing n, and becomes less than 50% at n 3, relative to the case of n = 1. The experimental results cannot be explained in terms of projectile stopping cross sections nor by the clearing-the-way effect. It is probable that the suppressed electron emission is a result of the suppression of the transport or surface transmission of the produced low-energy electrons, rather than of the suppression of ionization.

Irradiation tests of critical components for remote handling system in gamma radiation environment

Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Furuya, Kazuyuki; *; Tada, Eisuke; Shibanuma, Kiyoshi; Koizumi, Koichi; Okawa, Yoshinao; Morita, Yosuke; et al.

JAERI-Tech 96-011, 111 Pages, 1996/03

JAERI-Tech-96-011.pdf:5.9MB

no abstracts in English

Evaluation of charge-changing cross sections of fast carbon cluster ions through carbon foil

Adachi, Masahiro; Saito, Yuichi; Chiba, Atsuya; Narumi, Kazumasa; Kaneko, Toshiaki*

no journal, , 

no abstracts in English