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Journal Articles

Non-destructive beam spatial profile measurement using a gas sheet monitor for a high-intensity ion beam

Yamada, Ippei; Wada, Motoi*; Kamiya, Junichiro; Kinsho, Michikazu

Journal of Physics; Conference Series, 2244, p.012077_1 - 012077_6, 2022/04

no abstracts in English

Journal Articles

General overview of the research project investigating the radionuclide solution behavior in mock mortar matrix modeled after conditions at the Fukushima-Daiichi Nuclear Power Station

Igarashi, Go*; Haga, Kazuko*; Yamada, Kazuo*; Aihara, Haruka; Shibata, Atsuhiro; Koma, Yoshikazu; Maruyama, Ippei*

Journal of Advanced Concrete Technology, 19(9), p.950 - 976, 2021/09

Journal Articles

High-intensity beam profile measurement using a gas sheet monitor by beam induced fluorescence detection

Yamada, Ippei; Wada, Motoi*; Moriya, Katsuhiro; Kamiya, Junichiro; Saha, P. K.; Kinsho, Michikazu

Physical Review Accelerators and Beams (Internet), 24(4), p.042801_1 - 042801_13, 2021/04

A transverse beam profile monitor that visualizes a two-dimensional beam-induced fluorescent image was developed. The monitor employs a sheet-shaped gas flow formed by a technique of rarefied gas dynamics. A simplified analysis method was developed to reconstruct the beam intensity profile from the obtained image. The developed profile monitor and the analysis method were applied to measure the J-PARC 3 MeV H$$^-$$ beam profile. The root mean square values of the profiles were consistent with the ones obtained by a wire-scanning-type beam profile monitor. The beam loss due to the gas sheet injection was measured as a beam-current reduction. The amount of the beam current decreased in proportion to the gas sheet flux and the reduction ranged from 0.004 to 2.5%. The assembled system was capable of reconstructing a beam profile from a single shot beam pulse (1.7$$times$$10$$^{13}$$ protons in 50 $$mu$$s).

Journal Articles

A Project focusing on the contamination mechanism of concrete after the accident at Fukushima Daiichi Nuclear Power Plant

Yamada, Kazuo*; Maruyama, Ippei*; Haga, Kazuko*; Igarashi, Go*; Aihara, Haruka; Tomita, Sayuri*; Kiran, R.*; Osawa, Norihisa*; Shibata, Atsuhiro; Shibuya, Kazutoshi*; et al.

Proceedings of International Waste Management Symposia 2021 (WM 2021) (CD-ROM), 10 Pages, 2021/03

Journal Articles

Development of a laser chipping technique combined with water jet for retrieval of fuel debris at Fukushima Daiichi Nuclear Power Station

Yamada, Tomonori; Takebe, Toshihiko*; Ishizuka, Ippei*; Daido, Hiroyuki*; Hanari, Toshihide; Shibata, Takuya; Omori, Shinya*; Kurosawa, Koichi*; Sasaki, Go*; Nakada, Masahiro*; et al.

Journal of Nuclear Science and Technology, 56(12), p.1171 - 1179, 2019/12

 Times Cited Count:1 Percentile:23.13(Nuclear Science & Technology)

We describe a new chipping technique combined with a water-jet technique as one of the candidate techniques for the retrieval of fuel debris and support structures as part of the decommissioning of the Fukushima Daiichi Nuclear Power Station. We performed proof-of-principle experiments to demonstrate the removal capability of metal parts, where we focused on the observation of removal processes from a metallic sample using a 5.5-kW continuous wave fiber laser combined with continuous and pulsed water jets.

Journal Articles

Evaluation of 2-D transverse beam profile monitor using gas sheet at J-PARC LINAC

Kamiya, Junichiro; Okabe, Kota; Kinsho, Michikazu; Moriya, Katsuhiro; Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Wada, K.*

Journal of Physics; Conference Series, 1350, p.012149_1 - 012149_6, 2019/12

 Times Cited Count:2 Percentile:84.98

To obtain a getter effect to titanium vacuum duct surface, the method to remove the oxide on the surface by sputtering with ionized molecules has been developed. In the method, a sheet-shaped gas distribution with a uniform and high density is generated through a narrow slit by a small amount of gas. In this report, the gas density distribution was calculated by the Monte Carlo simulation code. As a result, it was found that a gas injection from both directions was effective to generate uniform density distribution. Furthermore, the gas injection method was applied to a non-destructive beam profile monitor, that detects ions generated by the interaction between gas molecules and beam. In this monitor, dependence of the beam profile on the injected gas amount was measured. A small amount of injected gas was found to be ideal for the beam profile measurements in the unsaturated and a high S/N ratio region.

Journal Articles

Development of a gas distribution measuring system for 2-D beam profile monitor

Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu

Vacuum and Surface Science, 62(7), p.400 - 405, 2019/07

no abstracts in English

Journal Articles

Development of a gas distribution measuring system for gas sheet beam profile monitor

Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu

Proceedings of 10th International Particle Accelerator Conference (IPAC '19) (Internet), p.2567 - 2570, 2019/06

no abstracts in English

Journal Articles

New project on the analysis of contamination mechanisms of concrete at the Fukushima Daiichi Nuclear Power Station

Yamada, Kazuo*; Maruyama, Ippei*; Koma, Yoshikazu; Haga, Kazuko*; Igarashi, Go*; Shibuya, Kazutoshi*; Aihara, Haruka

Proceedings of International Waste Management Symposia 2019 (WM 2019) (CD-ROM), 6 Pages, 2019/03

Journal Articles

Development of gas distribution measurement system for a two-dimensional beam profile monitor with a sheet-shaped gas

Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu

Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.88 - 92, 2018/08

no abstracts in English

Journal Articles

Demonstration of laser processing technique combined with water jet technique for retrieval of fuel debris at Fukushima Daiichi Nuclear Power Station

Hanari, Toshihide; Takebe, Toshihiko*; Yamada, Tomonori; Daido, Hiroyuki; Ishizuka, Ippei*; Omori, Shinya*; Kurosawa, Koichi*; Sasaki, Go*; Nakada, Masahiro*; Sakai, Hideaki*

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 3 Pages, 2017/04

In decommissioning of Fukushima Daiichi Nuclear Power Station, a retrieval process of fuel debris in the Primary Containment Vessel by a remote operation is one of the key issues. In this process, prevention of spreading radioactive materials is one of the important considerations. Furthermore, an applicable technique to the process requires keeping of reasonable processing-efficiency. We propose to use the combined technique including a laser light and a water jet as a retrieval technique of the fuel debris. The laser processing technique combined with a repetitive pulsed water jet could perform an efficient retrieval processing. Our experimental result encourages us to promote further development of the technique towards a real application at Fukushima Daiichi Nuclear Power Station.

Journal Articles

Surface preparation and characterization of single crystalline $$beta$$-FeSi$$_{2}$$

Yamada, Yoichi; Wakaya, Ippei*; Ouchi, Shinji*; Yamamoto, Hiroyuki; Asaoka, Hidehito; Shamoto, Shinichi; Udono, Haruhiko*

Surface Science, 602(18), p.3006 - 3009, 2008/09

 Times Cited Count:6 Percentile:31.88(Chemistry, Physical)

Well-defined clean surfaces of single crystalline $$beta$$-FeSi$$_{2}$$ have for the first time been prepared and characterized at the atomic scale. Surface oxide was removed by heating the crystal at 850 $$^{circ}$$C in ultra-high vacuum (UHV), resulted in an atomically-flat, clean surface. Scanning tunneling microscope (STM) and low-energy electron diffraction (LEED) measurements reveal the absence of long-range surface reconstruction in the low-index (100), (101) and (110) surfaces, which is unique among compound semiconductors. However a significant number of surface defects could still be found within the clean surface. Characterizing and controlling of those surface defects will be necessary in order to use this material in applications.

Oral presentation

RHEED observation of surface on $$beta$$-FeSi$$_{2}$$ single crystals

Wakaya, Ippei*; Muroga, Masataka*; Ouchi, Shinji*; Udono, Haruhiko*; Yamada, Yoichi; Yamamoto, Hiroyuki; Kikuma, Isao*

no journal, , 

RHEED observation of surface has been performed on $$beta$$-FeSi$$_{2}$$ single crystals.

Oral presentation

Preparation and characterization of clean surface of $$beta$$-FeSi$$_{2}$$ single crystal

Yamada, Yoichi; Wakaya, Ippei*; Ouchi, Shinji*; Yamamoto, Hiroyuki; Udono, Haruhiko*

no journal, , 

Preparation method of well defined $$beta$$-FeSi$$_{2}$$(110) single crystal surface has been investigated.

Oral presentation

Homoepitaxy of $$beta$$-FeSi$$_{2}$$ thin films on various oriented substrates by MBE

Ouchi, Shinji*; Wakaya, Ippei*; Udono, Haruhiko*; Yamada, Yoichi; Yamamoto, Hiroyuki; Esaka, Fumitaka

no journal, , 

Homoepitaxial formation of $$beta$$-FeSi$$_{2}$$ thin films on various oriented substrates has been discussed.

Oral presentation

Surface analysis on single-crystalline $$beta$$-FeSi$$_{2}$$

Mao, W.; Wakaya, Ippei*; Yamada, Yoichi; Esaka, Fumitaka; Yamamoto, Hiroyuki; Shamoto, Shinichi; Yamaguchi, Kenji; Udono, Haruhiko*

no journal, , 

Thin films of semiconducting $$beta$$-FeSi$$_{2}$$ keep attracting considerable attentions for their promising applicability to the Si-based optoelectronics devices. Recently, large single-crystalline $$beta$$-FeSi$$_{2}$$ has successfully been synthesized, providing a substrate for a well-defined homoepitaxy film. As a first step toward good homoepitaxy of $$beta$$-FeSi$$_{2}$$, we prepare and characterize low-index surfaces of $$beta$$-FeSi$$_{2}$$ single crystal. Both LEED and STM reveal the absence of the long-ranged surface reconstruction for each face, which is favorable for the homoepitaxy on this substrate. On the other hand, STM suggests a presence of a significant amount of surface defects for each face, which should be improved in the next step. In addition to structural analysis, the stoichiometry of clean surfaces will be discussed on the basis of XPS and SIMS measurements.

Oral presentation

Investigation of deposit condition in the first stage of $$beta$$-FeSi$$_{2}$$ homoepitaxial growth

Wakaya, Ippei*; Ochiai, Kunihito*; Udono, Haruhiko*; Nagano, Takatoshi*; Yamada, Yoichi; Yamamoto, Hiroyuki; Esaka, Fumitaka

no journal, , 

Deposit condition in the first stage of $$beta$$-FeSi$$_{2}$$ homoepitaxial growth has been investigated.

Oral presentation

Surface observation of single crystalline $$beta$$-$${rm FeSi_2}$$

Yamada, Yoichi*; Wakaya, Ippei*; Ouchi, Shinji*; Udono, Haruhiko*; Tsuru, Tomohito; Esaka, Fumitaka; Yamamoto, Hiroyuki

no journal, , 

no abstracts in English

Oral presentation

Development on processing technology with combination of laser and water jet for decommissioning of Fukushima Daiichi Nuclear Power Station, 1; Capability of the processing technique

Takebe, Toshihiko*; Hanari, Toshihide; Yamada, Tomonori; Daido, Hiroyuki; Ishizuka, Ippei*; Omori, Shinya*; Kurosawa, Koichi*; Sasaki, Go*; Nakada, Masahiro*; Sakai, Hideaki*

no journal, , 

no abstracts in English

Oral presentation

Development on processing technology with combination of laser and water jet for decommissioning of Fukushima Daiichi Nuclear Power Station, 2; Observation of gouging processes using a high speed camera

Hanari, Toshihide; Takebe, Toshihiko*; Yamada, Tomonori; Daido, Hiroyuki; Ishizuka, Ippei*; Omori, Shinya*; Kurosawa, Koichi*; Sasaki, Go*; Nakada, Masahiro*; Sakai, Hideaki*

no journal, , 

no abstracts in English

32 (Records 1-20 displayed on this page)