Nakamura, Tetsuya*; Imaizumi, Mitsuru*; Sato, Shinichiro; Sugaya, Takeyoshi*; Mochizuki, Toru*; Okano, Yoshinobu*; Oshima, Takeshi
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.73 - 76, 2015/11
The radiation effect on GaAs p-i-n solar cells with quantum dot (QD) in the i-layer was investigated. In a previous work, we particularly noted the degradation of fill-factor (FF) for the QD cells. In this work, to clarify the reason of the FF degradation in QD cells, generation current due to low-energy proton irradiation, which we call ion beam induced current (IBIC), was observed to characterize behavior of the generated minority carrier by the protons in the depletion region where QDs are located. The energy of protons was adjusted to damage the depletion region, and decrease of generation current was measured during the proton irradiation. The results suggest that the serious degradation of FF is caused by a decrease of the carrier collection efficiency in the depletion region due to proton damage.
Abderrahmane, A.*; Ko, P. J.*; Okada, Hiroshi*; Sato, Shinichiro; Oshima, Takeshi; Sandhu, A.*
IEEE Electron Device Letters, 35(11), p.1130 - 1132, 2014/11
The longitudinal and transverse magnetoresistances of AlGaN/GaN heterostructure-based micro-Hall sensors were compared with samples irradiated with protons with an energy of 380 keV and fluence of 10 (protons/cm). Increases in the elastic and inelastic scattering were deduced from weak localization behavior in both samples. The AlGaN/GaN micro-Hall sensors showed stable magnetic sensitivity in non and irradiated samples and increased resistivity after proton irradiation yielded an enhanced magnetoresistance sensitivity in nonirradiated sensors from 160 to 417 V/(A T). The minimum detectable magnetic field of irradiated micro-Hall sensors determined from magneto-voltage measurements at 4 K was similar to the minimum detectable magnetic field in the nonirradiated sensors.
Hubbard, S.*; Sato, Shinichiro; Schmieder, K.*; Strong, W.*; Forbes, D.*; Bailey, C. G.*; Hoheisel, R.*; Walters, R. J.*
Proceedings of 40th IEEE Photovoltaic Specialists Conference (PVSC-40) (CD-ROM), p.1045 - 1050, 2014/06
Baseline and quantum dot (QD) GaAs pn-junction diodes were characterized by deep level transient spectroscopy before and after both 1MeV electron irradiation and 140 keV proton irradiation. Prior to irradiation, the addition of quantum dots appeared to have introduced a higher density of defects at EC-0.75 eV. After 1 MeV electron irradiation the well-known electron defects E3, E4 and E5 were observed in the baseline sample. In the quantum dot sample after 1 MeV electron irradiation, defects near E3, E4 and EC-0.75 eV were also observed. Compared to the irradiated baseline, the QD sample shows a higher density of more complex E4 defect and a lower density of the simple E3 defect, while the EC-0.75 eV defect seemed to be unaffected by electron irradiation. As well, after proton irradiation, well known proton defects PR1, PR2, PR4' are observed. The QD sample shows a lower density PR4' defects and a similar density of PR2 defects, when compared to the proton irradiated baseline sample.
Maximenko, S.*; Lumb, M.*; Hoheisel, R.*; Gonzlez, M.*; Scheiman, D.*; Messenger, S.*; Tibbits, T. N. D.*; Imaizumi, Mitsuru*; Oshima, Takeshi; Sato, Shinichiro; et al.
Proceedings of 40th IEEE Photovoltaic Specialists Conference (PVSC-40) (CD-ROM), p.2144 - 2148, 2014/06
In this paper, a complex analysis of the radiation response of GaAs solar cells with multi quantum wells (MQW) incorporated in the i-region of the device is presented. Electronic transport properties of the MQW i-region were assessed experimentally by the electron beam induced current (EBIC) technique. A 2-D EBIC diffusion model was applied to simulate EBIC line scans across device structure for different radiation doses. The results are interpreted using numerical modeling of the electrical field distribution at different radiation levels. Type conversion from n- to p-type was found in MQW i-region at displacement damage dose as low as low as 1 MeV MeV/g. This is supported by experimental and simulated EBIC and electric field distribution results.
Laird, J. S.; Hirao, Toshio; Onoda, Shinobu; Ito, Hisayoshi
Journal of Applied Physics, 98(1), p.013530_1 - 013530_14, 2005/07
no abstracts in English
Lan, K. N.*; Lam, N. D.*; Nagasawa, Naotsugu; Yoshii, Fumio; Kume, Tamikazu
Chitin and Chitosan; Chitin and Chitosan in Life Science, p.289 - 290, 2001/00
no abstracts in English
Lan, K. N.*; Lam, N. D.*; Yoshii, Fumio; Kume, Tamikazu
Shokuhin Shosha, 35(1-2), p.40 - 43, 2000/09
no abstracts in English
Mizuta, Shunji; ;
JNC-TN9400 2000-048, 28 Pages, 2000/04
ODS (Oxide Dispersion Strengthened) ferritic-martainsitic steels are one of the most prospective cladding materials for advanced fast breeder reactors, since they are expected to have excellent swelling resistance and superior high temperature strength due to the finely distributed stable oxide particles(YO). Properties and the tentative strength equations for ODS ferritic-martainsitic were proposed on the basis of the latest data to apply to the feasibility study of the sodium coolant MOX fuel plant. The items of equations are follows. (1)creep rupture strength (2)correction factor of creep rupture strength (in Na and in reactor) (3)outer surface eorrosion (Na) (4)inner surface corrosion (in MOX fuel pin) (5)thermal conductivity
*; *; *; *; Hasegawa, Makoto;
JNC-TY9400 2000-007, 50 Pages, 2000/03
no abstracts in English
JNC-TN9420 2000-005, 28 Pages, 2000/03
In the first phase of the feasibility study, their basic objectives are presentating the feasible image and scenario of development of the FBR cycle system, which is composed of the fast reactor, spent fuel reprocessing and fuel manufacturing facility. In the development of the FBR system in this phase, various ideas of plants are to be studied, which include coolant types such as sodium, heavy metals, gases(CO, He), wator, and middle or small size of the reactor, and fuel types (MOX, metal and nitride). In this report, as a part of this study, materials used for the core of the helium gas cooled reactor and their integrity (corrosion, mechanical and irradiation property) under high temperature helium atmosphere were investigated from open literatures.
; Toyama, Shinichi; ; ; Yamazaki, Yoshio; ; Omura, Akiko
JNC-TN9410 2000-007, 376 Pages, 2000/03
According to the Long-Term Program for Partitioning and Transmutation which was published by the Atomic Energy Commission in 1988, study on the transmutation using an electron accelerator, which was a part of the program, has been carried out in the O-arai Engineering Center. It is the study on converting radioactive fission products for example Strontium and Cesium to stable nuclides by photonuclear reaction caused by high energy gamma-ray made by an electron accelerator. It was thought that a 100mA-100MeV (10MW output power) accelerator would be needed in order to carry out the transmutation study in engineering phase. Therefore, development of the High-Current Electron Accelerator whose target had been 20mA-10MeV (200 kW output power) accelerator was carried out as development of elemental technologies on beam stabilization. The conceptual design of the accelerator was started in 1989. In March 1997, the main facility of this accelerator was completed. The test operation was carried out to confiim the performance of the accelerator from January, 1999 to December. As the result, an output of about 14 kW was achieved. In addition, the electron beam of 40 kW could be to accelerate in short time. In this report, the design, fabrication and evalution of performance of the facilities are presented.
; ; Toyama, Shinichi; Hasegawa, Makoto
JNC-TN9410 2000-005, 182 Pages, 2000/03
According to the Long-term Program for Partitioning and Transmutation which was published by the Atomic Energy Commission in 1988, study on the transmutation using an electron accelerator, which was a part of the program, has been carried out in the O-arai Engineering Center. It is the study on converting radioactive fission products for example Strontium and Cesium to stable nuclides by photonuclear reaction caused by high energy gamma-ray made by an electron accelerator. It was thought that a 100mA-100Mev (10MW output power) accelerator would be needed in order to carry out the transmutation study in engineering phase. Therefore, development of the High-Current Electron Accelerator whose target had been 20mA-10Mev (200kW output power) accelerator was carried out as development of elemental technologies on beam stabilization. Construction of the accelerator was completed in March, 1997, afler development of the elemental devices. After the facility assessment, the full-scale experiment of the accelerator was started in January, 1999. However, the reform of the Power Reactor and Nuclear Fuel Development Corporation caused by the fire and explosion accident in the Asphalt Bitumenizing Facility was hardly discussed between the completion and the starting the experiment. It was decided that development of the accelerator would be terminated until the fiscal year 1999, results of the development would be summarized, and the developed accelerator would be planed to utilize as a beam utilization facility, in the Medium-Long-term Project Program of the Japan Nuclear Fuel Cycle Development Institute which was in March, 1999. It showed the direction that research and development for transmutation would be terminated. According to the Medium-Long-Term Project Program, the utilization of the accelerator was discussed, and research themes of the utilization of the accelerator in the various fields as well as nuclear field were investigated.
JNC-TN9400 2000-047, 114 Pages, 2000/03
Prediction of weld residual stresses by a general finite element code is beneficial to the improvement of the accuracy of integrity assessment and residual life assessment of FBR plants. This reports develops an evaluation method of weld residual stresses using FINAS. Firstly, we suggested a basic procedure derived from parametric analyses with a simple weld joint model. The procedure can be summarized as follows: (1)For heat conduction analysis, prepare different models corresponding to the number of layers to be modeled. Hand over the analytical results to the following model. (2)Use multi-linear stress-strain curves for modeling the stress-strain response of base metal and weld metal. Use the isotropic hardening rule. (3)When metals are melt, use a user-subroutine to keep stresses from arising. (4)Put the thermal expansion coefficient as zero when heat is being input. Then, using the above procedure and TIG welding, we predicted the weld residual stresses of plate and tube. The results agreed well with the other reports, showing the suggested procedure was reasonable.
JNC-TN9400 2000-045, 64 Pages, 2000/03
During the irradiation, the Pu redistribution phenomena would occur in the FBR MOX fuel pellets. The phenomena would considerably affect on the thermal properties of the fuels, therefore, it is need to establish the evaluation method for Pu redistribution phenomena. ln JNC, the efforts for development of the evaluation model for the phenomena had been continued and the simple evaluation model was constructed in 1992. In this work, the modification of the simple model developed in JNC has been done and the following results were obtained. (1)Based on the recent data of the MOX fuel irradiation tests, the evaluation model for Pu redistribution phenomena constructed in l992 is modified. And the model is included into the fuel performance analysis code "CEDAR". (2)To calibrate the modified CEDAR code, it is confirmed that the uncertainty in the Pu concentration evaluation for the center of the fuel pellet at EOL is about 3wt.%. (3)Based on the results of the evaluations using the modified CEDAR code, it is found that, in the early stage of the irradiation, the Pu redistribution is controlled by the vapor transportation mechanism via pores, and after that, the Pu redistribution is kept in progress due to the thermal diffusion mechanism with the change of the Pu concentration due to the degradation of U and Pu by fissions. And it is also found that the O/M ratio dependence of the U-Pu inter diffusion coefficients would affect on the Pu redistribution mechanisms, in especial, in the early stage of the irradiation.
; Yamagata, Ichiro; ; Akasaka, Naoaki
JNC-TN9400 2000-046, 24 Pages, 2000/02
lt is well known that solute atoms are segregated on surface, grain boundary, etc. and composition changed partially in irradiated austenitic stainless steel. For understanding radiation induced segregation (RIS), we adopt a Fe-15Cr-20Ni-x (x: Si, Mo) which is basically alloy system in PNC1520, and size of Si, Mo are different from matrix atoms to investigate RIS behaviors. The specimens were irradiated by "Joyo" fast reactor that irradiation condition is 3.5 10 n/m (E>0.1Mev) at 476C. After irradiation, the specimen were observed and analyzed with EDS (Energy Dispersive X-ray Spectroscope) of 400kV TEM (Transmission Electron Microscope). The behavior of RIS depends on size of solute atoms of alloy. For example, oversized atoms are decreased and undersized atoms are increased in sink. RIS of voids are as same as or more than grain boundaries and smaller than precipitates. The void denuded zone was existed nearby G.B. in case of combinations between the grains from G.B.0ne of the reasons in this, the voids swepted by moving G.B. in radiation induced G.B. migration.
JNC-TN9450 2000-002, 335 Pages, 1999/10
This report summarizes the material test dala of SUS304 welded joints. Numbers of the data are as follows: [Tensile tests 71 (Post-irradiation: 39, others: 32) [Creep tests 77 (Post-irradiation: 20, others: 57) [Fatigue tests 50 (Post-irradiation: 0) [Creep-fatigue tests 14 (Post-irradiation: 0) This report consists of the printouts from "the structural material data processing system".
JNC-TN9450 2000-001, 1370 Pages, 1999/10
This report summarizes the material test data of SUS304. Numbers of the data are as follows. (1)Tensile tests 738 (Post-irradiation: 250, others: 488) (2)Creep tests 434 (Post-irradiation: 89, others: 345) (3)Fatigue tests 612 (Post-irradiation: 60, others: 552) (4)Creep-fatigue tests 200 (Post-irradiation: 40, others: 160) This report consists of the printouts from "the structural material data processing system".
Hoshasen To Sangyo, (77), p.32 - 36, 1998/00
no abstracts in English
M.A.Malek*; Matsuhashi, Shimpei; Kume, Tamikazu
Int. J.Mushroom Sci., 2(2), p.27 - 32, 1998/00
no abstracts in English