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209 results on '"Iwamoto, Naoya"'

58. Microbeam Irradiation Effects on Transmission Diamond Detector

Author

Kada, Wataru, Sato, Takahiro, Iwamoto, Naoya, Shinobu, Onoda, Grilj, Veljko, Skukan, Natko, Makino, Takahiro, Koka, Masashi, Jaksic, Milko, Oshima, Takeshi, and Kamiya, Tomihiro

Subjects
Particle Detector, Polarization, Microbeam, equipment and supplies, Single Ion Hit, Radiation Hardness
Abstract

Response of thin film CVD diamond to the ionized particle irradiation was investigated for the utilization as a transmission detector in the end-station of the microbeam line connecting to the AVF cyclotron at JAEA/Takasaki. A spectroscopy-grade 50 micrometers-thick film Single Crystalline CVD diamond was characterized using Ion Beam Induced Charge (IBIC) and Transient Ion Beam Induced Current (TIBIC) systems. Significant decrease in IBIC signals was observed temporally during a microbeam irradiation period. Peak degradation was easily recovered in a short time by release of biases thus it seems to be caused by the polarization effect due to charge-capture by defects in the surface layer of diamond., 形態: カラー図版あり, 著者人数: 11名, Physical characteristics: Original contains color illustrations, Number of authors: 11, 資料番号: AA0061889015, レポート番号: JAXA-SP-12-008E

Published
2013

59. AMS-14C and tephra ages of sediments accumulated in the depression between double ridges northwest of Mt.Kanmuriyama on the boundary between Gifu and Fukui prefectures

Author

Niwa, Ryota, Kojima, Satoru, Iwamoto, Naoya, Kaneda, Heitaro, and Ohtani, Tomoyuki

Subjects
二重山稜, 凹地埋積堆積物
Abstract

The AMS-14C ages of wood fragments and age of tephra in the sediments accumulated in the depression between the double ridges were determined in order to clarify the development history of the ridges northwest of Mt. Kanmuriyama, Gifu and Fukui prefectures. Nine boreholes arranged along the line perpendicular to the ridge were drilled by the hand auger boring. The westernmost K2 core with thickest sediments includes wood fragments suitable for the AMS-14C age determination at the depths of 82, 138 and 195 cm; they yield 1234-1060, 6161-5996 and 7931-7731 cal BP, respectively. The tephra layer recovered from the depth of 148 cm of the same core is correlated with the Kikai Akahoya tephra (K-Ah) about 7300 cal BP. The AMS-14C ages of wood fragments embedded at the depths of 90 and 112 cm in the K8 core located eastern part of the basin are 4091-3925 and 6179-5938 cal BP, respectively. However, the peak of content of volcanic glass originated from the K-Ah tephra appears between the two wood fragment horizons., 岐阜福井県境冠山北西に位置する二重山稜地形の発達過程を明らかにするため，凹地埋積堆積物中に含まれる木片のAMS-14C年代測定とテフラの年代決定を行った.おおよそ南北方向の稜線に直交する方向に9箇所ハンドオーガーボーリングを行いコアを採取した.堆積物の層厚が一番厚かった凹地西端のK2コアにおいては,深度82,138,195cmから木片を採取し,深度148cmからテフラを採取した.得られた木片のAMS-14C年代は上位から1234-1060,6191-5996,7931-7731cal BPであった.テフラについては,火山ガラスの屈折率を測定した結果,鬼界アカホヤ火山灰(K-Ah)に対比され,その降灰年代は7300cal BPであることが分かった.また,凹地東端に近いK8コアの深度90,112cmの層準から得られた木片の年代は,4138-3925cal BP,6179-5938cal BPで,その聞には,K-Ah起源の火山ガラスの含有率ピークがみられた., 名古屋大学年代測定総合研究センターシンポジウム報告

Published
2013

75. Displacement damege and single event effects on SiC devices

Author

Onoda, Shinobu, Iwamoto, Naoya, Kojima, Kazutoshi, Kawano, Katsuyasu, and Oshima, Takeshi

Abstract

第19回高温エレクトロニクス研究会(2009年3月12日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The 19th ISAS research meeting on High Temperature Electronics (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA), March 12, 2009), 原子力機構では､パワーデバイス･耐放射線性デバイスとしての利用が期待される炭化ケイ素(SiC; Silicon Carbide)半導体に対して､トータルドーズ効果､はじき出し損傷効果､およびシングルイベント効果といった放射線影響に関する研究を行っている｡今回は､はじき出し損傷効果に関する研究の一例として､SiCダイオ-ド(粒子検出器)にガンマ線､電子線､陽子線を照射し､照射前後のキャリア濃度や粒子検出器の性能を示す指標である電荷収集効率(CCE; Charge Collection Efficiency)を評価した結果について報告する｡また､シングルイベント効果に関する研究の一例として､SiCダイオードに重イオン1個を照射し､その際に発生する過渡電流を計測するシステムや測定結果について紹介する｡, Silicon Carbide (SiC) is one of the most candidate semiconductor materials for high-power and rad-hard electronics. We have studied the total ionizing dose, displacement damage, and single event effects on SiC devices. One of the experimental results of displacement damage effects on SiC diodes is introduced here. The carrier density of epitaxial layer and Charge Collection Efficiency (CCE) reduce with increase in fluence of gamma-ray, 1 MeV electrons, and 65 MeV protons. In addition to this, the experimental setup and results for transient current induced by an ion strike are expressed in this presentation., 資料番号: AA0064294007

Published
2009

91. A Study of Predicting Ability in State-Action Pair Prediction: Adaptability to an Almost-Periodic Disturbance

Author

Kurashige, Kentarou, Sugimoto, Masashi, Iwamoto, Naoya, Johnston, Robert, Kanazawa, Keizo, and Misaki, Yukinori

Abstract

When a robot considers an action-decision based on a future prediction, it is necessary to know the property of disturbance signals from the outside environment. On the other hand, the properties of disturbance signals cannot be described simply, such as non-periodic function, nonlinear time-varying function nor almost-periodic function. In case of a robot control, sampling rate for control will be affected description of disturbance signals such as frequency or amplitude. If the sampling rate for acquiring a disturbance signal is not correct, the action will be taken far from its actual property. In general, future prediction using machine learning is based on the tendency obtained through past training or learning. In this case, an optimal action will be determined uniquely based on a property of disturbance. However, in this type of situation, the learning time increases in proportional to the amount of training data, either, the tendency may not be found using prediction, in the worst case. In this paper, we focus on prediction for almost-periodic disturbance. In particular, we consider the situation where almost-periodic disturbance signals occur. From this perspective, we propose a method that identifies the frequency of an almost- periodic function based on the frequency of the disturbance using Fourier transform, nearest-neighbor one-step-ahead forecasts and Nyquist-Shannon sampling theorem.

Published
2017
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