Refine your search:     
Report No.
Search Results: Records 1-20 displayed on this page of 105

Presentation/Publication Type

Initialising ...


Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...


Initialising ...


Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Fundamental aspects of neutron moderators and neutron beam optics for designing high intensity laser-driven neutron source

Ikeda, Yujiro; Shimizu, Hirohiko*

Reza Kenkyu, 46(11), p.641 - 646, 2018/11

In viewing significant progresses in technical achievement toward a high-intensity neutron source driven by a high-power laser came up with the high power laser development, we have reviewed the currently most advanced moderator system and neutron optics, which are the key elements for the neutron beam applications. Regarding the moderators, concepts adopted in J-PARC pulsed neutron source, which is one of most advanced system, were described to give a baseline design. Also a new direction of moderator concept is shown, which could be a high brightness candidate for the high-intensity laser driven system. On the neutron optics, the most fundamental consideration is primarily reviewed along with recent progress in new devises for enrichment of neutron-beam characteristics.

Journal Articles

Recent development of neutron detectors for pulsed compact neutron sources

Arikawa, Yasunobu*; Ikeda, Yujiro; Shimizu, Hirohiko*; Hanayama, Ryohei*; Kondo, Yasuharu*; Kurosawa, Shunsuke*

Reza Kenkyu, 46(11), p.634 - 640, 2018/11

Compact neutron sources have been used as various diagnostics such as a neutron diffraction, neutron resonant analysis, and neutron radiography. The developments of the neutron detectors are essential for all of these applications, while the techniques are strongly dependent on the neutron energy and the aim of the measurement. This paper reviews neutron detection techniques pertinent to promote compact neutron source uses. Along with general neutron detection systems with conventional counters for slow neutrons, we have highlighted detectors for high energy neutrons with high time resolution and high sensitivity which could be applied in a laser-driven compact neutron source.

Journal Articles

Report on OPIC Laser Solutions for Space and the Earth (LSSE 2017)

Ebisuzaki, Toshikazu*; Wada, Satoshi*; Saito, Norihito*; Fujii, Takashi*; Nishimura, Akihiko

Reza Kenkyu, 45(10), p.664 - 665, 2017/10

no abstracts in English

Journal Articles

Introduction to the special issue on "Application of laser techniques to maintenance and repair of the social infrastructure"

Daido, Hiroyuki

Reza Kenkyu, 45(7), p.397 - 398, 2017/07

In this special issue, we present laser techniques applied to maintenance and repair of the social infrastructure such as tunnels, electric power generation and transportation, nuclear facilities. Remote sensing, LIBS, LIDAR, remote technologies coupled with lasers and surface cleaning are reviewed in this issue.

Journal Articles

Contribution by incorporation of laser technology and robotics technology for Fukushima Daiichi Nuclear Power Plants decommissioning

Kawatsuma, Shinji

Reza Kenkyu, 45(7), p.413 - 417, 2017/07

Inside and surrounding area of reactor buildings of Fukushima Daiichi Nuclear Power Plants became high radiation condition because of radioactive materials release by the accidents caused by earthquake of Pacific coast on eastern and northern Japan. In the stage of emergency response to the accidents, more than 20 robots had been deployed, and some of them had equipped with laser technologies like as laser range finder. In the following decommissioning stage of the plans, operations under higher radiation condition will be required, so that varied laser technologies will be needed to fuse with robot technologies. Laser checker laser analysis would be expected besides laser range finder. However those technologies will be deployed under higher radiation condition, so radiation hardening and control stabilizing should be solved.

Journal Articles

Challenge towards the decommissioning of the Fukushima-Daiichi Nuclear Power Plant coupled with recovery of Fukushima

Daido, Hiroyuki

Reza Kenkyu, 45(3), p.135 - 136, 2017/03

I describe how important the challenge to Fukushima Daiichi and recovery of this area. From this point of view, scientific and technological trials originated from the disaster and accident should be based on the mission of Fukushima recovery.

Journal Articles

Computational science simulations of laser coating processes using a metal powder direct injection system

Muramatsu, Toshiharu

Reza Kenkyu, 44(12), p.799 - 803, 2016/12

no abstracts in English

Journal Articles

Observation of surface modification of multi-layered mirror induced by soft X-ray laser pulse

Nishikino, Masaharu; Ishino, Masahiko; Ichimaru, Satoshi*; Hatayama, Masatoshi*; Hasegawa, Noboru; Kawachi, Tetsuya

Reza Gakkai Dai-483-Kai Kenkyukai Hokoku; Tanhacho Ryoshi Bimu Hassei To Sono Oyo, p.25 - 28, 2015/12

X-ray ablation has been recently achieved using plasma soft X-ray lasers (SXRLs), laser plasma soft X-rays, and X-ray free electron lasers. In order to study the interactions between picosecond SXRL beams and material and multi-layered structure surfaces were irradiated with SXRL pulse. Following irradiation, the substrate surface was observed using a scanning electron microscope and an atomic force microscope. The surface modifications caused by the SXRL beam were clearly seen. The multi-layered mirror is the important component for the EUV lithography. Then, we have started the damage test of multi-layered structure, and the surface modifications caused by the SXRL pulse irradiations were confirmed.

Journal Articles

Preface to topical papers on frontier of pulsed electron beam for research on photoexcited dynamics

Itakura, Ryuji

Reza Kenkyu, 43(3), p.136 - 137, 2015/03

Recently, technique of pulsed electron beam generation combined with ultrafast laser technology has been developed for realization of time-resolved measurements. A variety of methods such as an electron gun with a photo-cathode and an optical gating of a CW electron beam are proposed and demonstrated. We will compiles topical papers on frontier of pulsed electron beam for research on photoexcited dynamics in one volume of "The Review of Laser Engineering". This paper is a preface for describing the aim and contents of this special volume.

Journal Articles

Observation of femtosecond laser ablation on Tungsten by using soft X-ray reflection and interference imaging

Nishikino, Masaharu; Hasegawa, Noboru; Tomita, Takuro*; Eyama, Tsuyoshi*; Kakimoto, Naoya*; Onishi, Naofumi*; Ito, Atsushi*; Baba, Motoyoshi*; Minami, Yasuo*; Kawachi, Tetsuya; et al.

Reza Gakkai Dai-471-Kai Kenkyukai Hokoku; Tanhacho Ryoshi Bimu Hassei To Sono Oyo, p.9 - 12, 2014/12

no abstracts in English

Journal Articles

Laser-induced breakdown spectroscopy for nuclear fuel material

Akaoka, Katsuaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

Reza Kenkyu, 42(12), p.918 - 922, 2014/12

For the remote analysis of the next generation nuclear fuel material containing minor actinide (MA), Laser Induced Breakdown Spectroscopy (LIBS) was applied to uranium oxide (U$$_{3}$$O$$_{8}$$) including a small amount of neodymium oxide (Nd$$_{2}$$O$$_{3}$$) as a simulated sample of MA. By using deconvolution technique for the spectra of Nd in U, the complex, overlapped and confused spectra were separated and their actual intensities were determined. As a result, the calibration curve with good linearity and the detection limit of less than 700 ppm were demonstrated.

Journal Articles

Application of Laser-Induced Breakdown Spectroscopy (LIBS) analysis to molten alloy production process

Ozu, Akira; Tachi, Yoshiaki; Arita, Yuji*

Reza Kenkyu, 42(12), p.913 - 917, 2014/12

Laser-induced breakdown spectroscopy (LIBS) analysis has been applied to the molten alloy production process, in which simulated metals (Zr, Cu, Sm, Ce) are used instead of nuclear metallic fuels contained minor actinide (MA), with the aim of in-situ monitoring the elementary composition of the surface of the molten alloy in a chamber and vapor particles generated from the surface of the molten alloy. The variation in the ratio of elementary composition of the surface of the molten alloy in the crucible was successfully observed depending on temperature of the crucible. The elementary composition of the vapor particles appeared in the molten alloy chamber was also measured. The practical experimental results show that LIBS technique is very useful for investigating the elementary composition in the process and understanding the behavior of molten alloy in the crucible.

Journal Articles

Application of laser-induced breakdown spectroscopy method for elements analysis of metal ions in an aqueous solution in nuclear reprocessing process control

Oba, Hironori; Saeki, Morihisa; Wakaida, Ikuo

Reza Kenkyu, 42(12), p.892 - 896, 2014/12

Laser-induced breakdown spectroscopy (LIBS) is an attractive technique for determining elemental composition in real time, in-situ and remotely without any sample preparation. The LIBS analysis of metal ions in an aqueous solution is available in process control and environmental monitoring. In the present paper, we have reviewed the LIBS methods for a liquid phase that tried to improve the detection sensitivity. We have performed the LIBS measurement with the sheet flow for the simultaneous determination of elements in the simulated high-level radioactive waste liquid and have discussed on the application possibility as a tool for online process monitoring.

Journal Articles

Report on 14th International Conference on X-Ray Lasers (ICXRL2014)

Nishikino, Masaharu; Kawachi, Tetsuya; Daido, Hiroyuki

Reza Kenkyu, 42(8), p.678 - 679, 2014/08

no abstracts in English

Journal Articles

High power laser developments with femtosecond to nanosecond pulse durations for laser shock science and engineering

Kiriyama, Hiromitsu; Mori, Michiaki; Suzuki, Masayuki*; Daito, Izuru*; Okada, Hajime; Ochi, Yoshihiro; Tanaka, Momoko; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; et al.

Reza Kenkyu, 42(6), p.441 - 447, 2014/06

We describe three specific high power laser systems that are being developed in our laboratory for many applications in high field science, nonlinear optics and material processing. We report on a femtosecond petawatt-class Ti:sapphire chirped-pulse amplification laser system that can produce a pulse energy of 20 J of 40 fs pulse duration, a picosecond high intensity Yb:YAG chirped-pulse amplification laser system that can generate a pulse energy of 100 mJ of 0.5 ps pulse duration, and a nanosecond high repetition rate Nd:YAG laser system that can provide an average power of 360 W with a pulse duration of 30 ns delivered at a 1 kHz repetition rate. We discuss the basic design aspects and present the results from our experimental investigations of these laser systems.

Journal Articles

Possibility of radiation reaction observation under ultraintense laser

Seto, Keita*; Koga, J. K.; Zhang, S.*

Reza Kenkyu, 42(2), p.174 - 178, 2014/02

Journal Articles

Observation of preformed plasma generated from a thin-foil target for laser-driven proton acceleration

Sagisaka, Akito; Pirozhkov, A. S.; Nishiuchi, Mamiko; Ogura, Koichi; Sakaki, Hironao; Yogo, Akifumi; Mori, Michiaki; Kiriyama, Hiromitsu; Okada, Hajime; Kanazawa, Shuhei; et al.

Reza Kenkyu, 42(2), p.160 - 162, 2014/02

High-intensity laser and thin-foil interactions produce high-energy particles, hard X-ray, high-order harmonics, and terahertz radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical and other applications. We have measured the proton yield from thin-foil targets irradiated with a high-intensity Ti:sapphire laser (J-KAREN) at JAEA. The longitudinal extent of the preformed plasma protruding from the front surface of the target is reduced by decreasing the duration of the amplified spontaneous emission (ASE) before the main pulse. The maximum proton energy in the target normal direction increases when the size of the preformed plasma is controlled.

Journal Articles

Application of general-purpose radiation transport code into study for laser-produced plasma ions acceleration

Sakaki, Hironao; Sato, Tatsuhiko; Kai, Tetsuya

Reza Kenkyu, 42(2), p.163 - 167, 2014/02

A general-purpose Monte Carlo particle and heavy ion transport code system (PHITS), which consists of various quantum dynamics models, was used to study laser-driven ion acceleration. Our simulation reasonably predicted not only the laser-driven ion's trajectories detected by the monitors but also the radiation shielding of these particles.

Journal Articles

Discrimination method of etch pits created by laser-accelerated protons and recoiled protons by photo-neutrons using CR-39

Kanasaki, Masato; Fukuda, Yuji; Kondo, Kiminori; Oda, Keiji*; Yamauchi, Tomoya*

Reza Kenkyu, 42(2), p.168 - 173, 2014/02

In laser-driven ion acceleration experiments using the cluster-gas targets, a significant amount of fast electrons, which drives the ion acceleration, are produced along with high energy ions with several-tens of MeV. In our recent experiment using CO$$_2$$ clusters embedded in H$$_2$$ gas conducted with the J-KAREN laser facility (1 J, 40 fs) at JAEA-KPSI, the maximum energy of electrons reaches up to 200 MeV. Such fast electrons can produce photo-neutrons via bremsstrahlung processes followed by photo-nuclear reactions. When the CR-39 is exposed to photo-neutrons, it records etchable tracks of generated ions depending on their species and energy as background noises. In order to diagnose the laser-accelerated protons precisely using CR-39, we have developed the discrimination method for laser-accelerated protons and photo-neutrons on CR-39 based on the incident angle and incident energy.

Journal Articles

Physics explored by intense optical high filed and source development

Kondo, Kiminori

Reza Kenkyu, 42(2), p.106 - 110, 2014/02

An instantaneous peak power generated with the advanced laser technology reached over peta-watt now. The focused intensity is possibly in the ultra-relativistic region, which opens a new experimental research. Some attractive themes are introduced.

105 (Records 1-20 displayed on this page)