| 1. |
- Miyoshi, Y., et al.
(author)
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The energization and radiation in geospace (ERG) project
- 2012
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In: Dynamics of The Earth's Radiation Belts and Inner Magnetosphere. - : American Geophysical Union (AGU). - 9780875904894 ; , s. 103-116
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Conference paper (peer-reviewed)abstract
- The Energization and Radiation in Geospace (ERG) project for solar cycle 24 will explore how relativistic electrons in the radiation belts are generated during space storms. This geospace exploration project consists of three research teams: the ERG satellite observation team, the ground-based network observation team, and the integrated data analysis/simulation team. Satellite observation will provide in situ measurements of features such as the plasma distribution function, electric and magnetic fields, and plasma waves, whereas remote sensing by ground-based observations using, for example, HF radars, magnetometers, optical instruments, and radio wave receivers will provide the global state of the geospace. Various kinds of data will be integrated and compared with numerical simulations for quantitative understanding. Such a synergetic approach is essential for comprehensive understanding of relativistic electron generation/loss processes through crossenergy and cross-regional coupling in which different plasma populations and regions are dynamically coupled with each other. In addition, the ERG satellite will utilize a new and innovative measurement technique for wave-particle interactions that can directly measure the energy exchange process between particles and plasma waves. In this paper, we briefly review some of the profound problems regarding relativistic electron accelerations and losses that will be solved by the ERG project, and we provide an overview of the project.
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| 2. |
- Kuroki, S. -I, et al.
(author)
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4H-SiC pseudo-CMOS logic inverters for harsh environment electronics
- 2017
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In: 11th European Conference on Silicon Carbide and Related Materials, ECSCRM 2016. - : Trans Tech Publications. - 9783035710434 ; , s. 669-672
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Conference paper (peer-reviewed)abstract
- For logic gate with higher voltage swing, 4H-SiC pseudo-CMOS logic inverter with four nMOS was suggested and demonstrated, and a high voltage swing of 4.4 V was achieved at VDD=5 V. Simple nMOS inverters were also investigated. Both of pseudo-CMOS and nMOS inverters were operated at a high temperature of 200ºC. For future SiC large integrated circuits, junction leakage current between n+ regions were also investigated with the comb-shaped test elements.
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| 3. |
- Kuroki, S. I., et al.
(author)
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Characterization of 4H-SiC nMOSFETs in harsh environments, high-temperature and high gamma-ray radiation
- 2016
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In: 16th International Conference on Silicon Carbide and Related Materials, ICSCRM 2015. - : Trans Tech Publications Ltd. - 9783035710427 ; , s. 864-867
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Conference paper (peer-reviewed)abstract
- Characteristics of 4H-SiC nMOSFETs with arsenic-doped S/D and NbNi silicide contacts in harsh environments of high-temperature up to 450°C, and high gamma-ray radiation up to over 100 Mrad, were investigated. At high temperature, field effect mobility increased as proportional to T3/2, and threshold voltage was shifted with temperature coefficients of -4.3 mV/K and -2.6 mV/K for oxide thicknesses of 10 nm and 20 nm, respectively. After Co60 gamma-ray exposure of 113 Mrad, the field effect mobility was varied within 8% for oxide thickness of 10 nm, however for 20 nm oxide thickness, this variation was 26%. The threshold voltage shifts were within 6%.
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| 4. |
- Nagatsuma, H., et al.
(author)
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4H-SiC nMOSFETs with As-Doped S/D and NbNi silicide ohmic contacts
- 2016
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In: 16th International Conference on Silicon Carbide and Related Materials, ICSCRM 2015. - : Trans Tech Publications Ltd. - 9783035710427 ; , s. 573-576
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Conference paper (peer-reviewed)abstract
- 4H-SiC nMOSFETs with As-doped S/D and NbNi silicide ohmic contacts were demonstrated for radiation-hard CMOS electronics. The threshold voltage Vth was designed to be 3.0 V by TCAD simulation, and was 3.6 – 3.8 V at the fabricated devices. On / off ratio was approximately 105.
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| 5. |
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| 6. |
- Nagatsuma, T., Nozawa, S., Buchert, S.C. and Fujii, R.
(author)
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High latitude Pi3 pulsations observed by the EISCAT VHF radar.
- 2001
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In: Advances in Space Research. ; 28:7, s. 1093-1096
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Journal article (peer-reviewed)abstract
- Long period irregular magnetic pulsations, Pi3, are found from EISCAT/VHF radar observations at the high latitude in the dawn sector on Sept. 29, 1996. From the comparison between the radar and ground magnetometer data, it is suggested that the meandering
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| 7. |
- Schrijver, Carolus J., et al.
(author)
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Understanding space weather to shield society : A global road map for 2015-2025 commissioned by COSPAR and ILWS
- 2015
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In: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 55:12, s. 2745-2807
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Journal article (peer-reviewed)abstract
- There is a growing appreciation that the environmental conditions that we call space weather impact the technological infrastructure that powers the coupled economies around the world. With that comes the need to better shield society against space weather by improving forecasts, environmental specifications, and infrastructure design. We recognize that much progress has been made and continues to be made with a powerful suite of research observatories on the ground and in space, forming the basis of a Sun Earth system observatory. But the domain of space weather is vast extending from deep within the Sun to far outside the planetary orbits and the physics complex including couplings between various types of physical processes that link scales and domains from the microscopic to large parts of the solar system. Consequently, advanced understanding of space weather requires a coordinated international approach to effectively provide awareness of the processes within the Sun Earth system through observation-driven models. This roadmap prioritizes the scientific focus areas and research infrastructure that are needed to significantly advance our understanding of space weather of all intensities and of its implications for society. Advancement of the existing system observatory through the addition of small to moderate state-of-the-art capabilities designed to fill observational gaps will enable significant advances. Such a strategy requires urgent action: key instrumentation needs to be sustained, and action needs to be taken before core capabilities are lost in the aging ensemble. We recommend advances through priority focus (1) on observation-based modeling throughout the Sun Earth system, (2) on forecasts more than 12 h ahead of the magnetic structure of incoming coronal mass ejections, (3) on understanding the geospace response to variable solar-wind stresses that lead to intense geomagnetically-induced currents and ionospheric and radiation storms, and (4) on developing a comprehensive specification of space climate, including the characterization of extreme space storms to guide resilient and robust engineering of technological infrastructures. The roadmap clusters its implementation recommendations by formulating three action pathways, and outlines needed instrumentation and research programs and infrastructure for each of these. An executive summary provides an overview of all recommendations.
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