Simulation study on dose and LET of neutron irradiation for biological experiments using spallation, reactor, and compact neutron sources

Sweet, M.*; Mishima, Kenji*; Harada, Masahide; Kurita, Keisuke; Iikura, Hiroshi; Tasaki, Seiji*; Kikuchi, Norio*

Quantum Beam Science (Internet), 9(2), p.11_1 - 11_17, 2025/04

https://doi.org/10.3390/qubs9020011

Neutron beam, being electrically neutral and highly penetrating, offers unique advantages for irradiation of biological species such as plants, seeds, and microorganisms. We comprehensively investigated the potential of neutron irradiation for inducing genetic mutations using simulations of J-PARC BL10, JRR-3 TNRF, and KUANS for spallation, reactor, and compact neutron sources.

Coulomb spike model of radiation damage in wide band-gap insulators

Costantini, J.-M.*; Ogawa, Tatsuhiko

Quantum Beam Science (Internet), 8(3), p.20_1 - 20_16, 2024/08

https://doi.org/10.3390/qubs8030020

A novel Coulomb spike concept is applied to the radiation damage induced in LiF and SiO with about the same mass density (2.65 g cm) by Ni and Kr ions of 1.0-MeV/u energy for about the same electronic energy loss (10 MeV/um). The distribution of ionizations and electrostatic energy gained in the electric field by the ionized atoms is computed with the PHITS code for both targets. Further, the atomic collision cascades induced by these low energy hot ions of about 500 eV are simulated with the SRIM2013 code. It is found that melting is reached in a small volume for SiO due to the energy deposition in the subthreshold events of nuclear collisions induced by the Si and O ions. For LiF, the phonon contribution to the stopping power of the lighter Li and F ions is not sufficient to induce melting, even though the melting temperature is lower than for SiO. The formation of amorphous domains in SiO is likely after fast quenching of the small molten pockets, whereas only point defects may be formed in LiF.

Stress measurement of stainless steel piping welds by complementary use of high-energy synchrotron X-rays and neutrons

Miura, Yasufumi*; Suzuki, Kenji*; Morooka, Satoshi; Shobu, Takahisa

Quantum Beam Science (Internet), 8(1), p.1_1 - 1_14, 2024/03

https://doi.org/10.3390/qubs8010001

Stress evaluation method by neutron diffraction for HCP-structured magnesium alloy

Harjo, S.; Gong, W.; Kawasaki, Takuro

Quantum Beam Science (Internet), 7(4), p.32_1 - 32_13, 2023/12

https://doi.org/10.3390/qubs7040032

Accuracy of measuring rebar strain in concrete using a diffractometer for residual stress analysis

Yasue, Ayumu*; Kawakami, Mayu*; Kobayashi, Kensuke*; Kim, J.*; Miyazu, Yuji*; Nishio, Yuhei*; Mukai, Tomohisa*; Morooka, Satoshi; Kanematsu, Manabu*

Quantum Beam Science (Internet), 7(2), p.15_1 - 15_14, 2023/05

https://doi.org/10.3390/qubs7020015

Coulomb spike modelling of ion sputtering of amorphous water ice

Constantini, J.-M.*; Ogawa, Tatsuhiko

Quantum Beam Science (Internet), 7(1), p.7_1 - 7_16, 2023/03

https://doi.org/10.3390/qubs7010007

Sputtering, emission of constituent atoms or molecules of materials induced by irradiation, is regarded as one of standard engineering techniques. According to some experimental data, emission of atoms whose direction is anti-parallel to incident radiation momentum was found among the sputtered atoms. Based on the standard approach, the thermal-spike model, atoms are evaporated by equillibrated thermal canonical ensemble resulted in by heat propagation therefore emission must be isotropic. Inspired by the fact that ionizations induced by ion irradiation are arranged linearly along the ion path, and the electric repulsion force between the ionizations tend to be parallel to irradiation axis, we developed an alternative approach in this study to explain the anisotropic emission. Using the spatial configuration of the irradiation-induced positive ions calculated by track-structure calculation code RITRACKS, the momentum of ions driven by the electric force was calculated. The calculated result explains the inverse jet of ions in case of 1 MeV proton and 1 MeV/u carbon ion irradiation to water. Moreover, the calculated sputtering yield also agrees with earlier experimental data.

Neutron stress measurement of W/Ti composite in cryogenic temperatures using time-of-flight method

Nishida, Masayuki*; Harjo, S.; Kawasaki, Takuro; Yamashita, Takayuki*; Gong, W.

Quantum Beam Science (Internet), 7(1), p.8_1 - 8_15, 2023/03

https://doi.org/10.3390/qubs7010008

Effect of irradiation on corrosion behavior of 316L steel in lead-bismuth eutectic with different oxygen concentrations

Okubo, Nariaki; Fujimura, Yuki; Tomobe, Masakatsu*

Quantum Beam Science (Internet), 5(3), p.27_1 - 27_9, 2021/09

https://doi.org/10.3390/qubs5030027

In an accelerator driven system (ADS), the beam window material of the spallation neutron target is heavily irradiated under severe conditions. Displacement damage and corrosion occur simultaneously because of high-energy neutron and/or proton irradiation in the lead-bismuth flow. The materials used in ADSs need to be compatible with the liquid metal, which is lead-bismuth eutectic (LBE), to prevent issues such as liquid metal embrittlement (LME) and liquid metal corrosion (LMC). In this study, the LMC behavior after ion irradiation of 316L austenitic steel is considered for self-ion irradiations followed by the corrosion tests. The 316L specimens were irradiated by 10.5 MeV-Fe ions at temperature of 450C up to 50 displacement per atom (dpa). After the corrosion test at 450C in LBE with low oxygen concentration, the surface of the non-irradiated area was not oxidized but corrosive morphology with pits, whereas the irradiated area was covered by an iron/chromium oxide layer. The surface of the irradiated area was covered by the duplex layers of iron and iron/chromium oxides in the case of higher oxygen concentration in LBE. It is suggested that irradiation can advance oxide layer formation because of enhanced Fe diffusion caused by the residual vacancies in 316L steel.

Internal strain distribution of laser lap joints in steel under loading studied by high-energy synchrotron radiation X-rays

Shobu, Takahisa; Shiro, Ayumi*; Kono, Fumiaki*; Muramatsu, Toshiharu; Yamada, Tomonori; Naganuma, Masayuki; Ozawa, Takayuki

Quantum Beam Science (Internet), 5(2), p.17_1 - 17_9, 2021/06

AA2021-0187.pdf:1.36MB

https://doi.org/10.3390/qubs5020017

The automotive industries employ laser beam welding because it realizes a high energy density without generating irradiation marks on the opposite side of the irradiated surface. Typical measurement techniques such as strain gauges and tube X-rays cannot assess the localized strain at a joint weld. Herein high-energy synchrotron radiation X-ray diffraction was used to study the internal strain distribution of laser lap joint PNC-FMS steels (2- and 5-mm thick) under loading at a high temperature. As the tensile load increased, the local tensile and compressive strains increased near the interface. These changes agreed well with the finite element analysis results. However, it is essential to complementarily utilize internal defect observations by X-ray transmission imaging because the results depend on the defects generated by laser processing.

Irradiation effects of swift heavy ions detected by refractive index depth profiling

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

Quantum Beam Science (Internet), 4(4), p.39_1 - 39_11, 2020/12

https://doi.org/10.3390/qubs4040039

Evolution of depth profiles of the refractive index in YAlO (YAG) crystals were studied under 200 MeV Xe ion irradiation. The index changes were observed at three different depth regions; (i) a plateau near the surface between 0 and 3 m in depth, which can be ascribed to the electronic stopping Se, (ii) a broad peak at 6 m in depth, and (iii) a sharp dip at 13 m in depth, which is attributed to the nuclear stopping Sn peak.