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Oda, Yasuhisa; Yamaguchi, Toshikazu*; Shiraishi, Yuya*; Komurasaki, Kimiya*; Kajiwara, Ken; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Infrared, Millimeter, and Terahertz Waves, 32(6), p.877 - 882, 2011/06
Times Cited Count：8 Percentile：43.66(Engineering, Electrical & Electronic)Oda, Yasuhisa; Yamaguchi, Toshikazu*; Komurasaki, Kimiya*; Kajiwara, Ken; Takahashi, Koji; Sakamoto, Keishi
Proceedings of IEEE MTT-S International Microwave Workshop Series (IMWS) on Innovative Wireless Power Transmission (IMWS-IWPT 2011), p.181 - 184, 2011/05
Oda, Yasuhisa; Sakamoto, Keishi; Komurasaki, Kimiya*
Purazuma Oyo Kagaku, 18(2), p.177 - 181, 2010/12
Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi; Komurasaki, Kimiya*
Japanese Journal of Applied Physics, 48(11), p.116001_1 - 116001_4, 2009/11
Times Cited Count：19 Percentile：58.36(Physics, Applied)Oda, Yasuhisa; Shibata, Teppei*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Propulsion and Power, 25(1), p.118 - 122, 2009/01
Times Cited Count：26 Percentile：82.34(Engineering, Aerospace)Oda, Yasuhisa; Kajiwara, Ken; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi; Komurasaki, Kimiya*
Proceedings of Global Congress on Microwave Energy Applications (GCMEA 2008/MAJIC 1st), p.567 - 570, 2008/08
Oda, Yasuhisa; Komurasaki, Kimiya*; Sakamoto, Keishi
Purazuma, Kaku Yugo Gakkai-Shi, 84(6), p.343 - 347, 2008/06
no abstracts in English
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Imai, Tsuyoshi*; Sakamoto, Keishi
Electrical Engineering in Japan, 161(2), p.1 - 7, 2007/11
Times Cited Count：1 Percentile：11.74(Engineering, Electrical & Electronic)Experiments on microwave plasma generation and its application to microwave beamed energy propulsion were conducted using a 1 MW-class, 170 GHz gyrotron. The microwave beam was focused using a parabola reflector and plasma was initiated near the focal point in the ambient air. Plasma propagated upstream in the microwave beam channel while absorbing microwaves. Its propagation velocity was supersonic when the microwave power density was greater than 75 kW/cm
. The propulsive impulse was measured using a cone-cylinder shaped thruster model. As a result, the maximum momentum coupling coefficient was obtained at a certain plasma propagation distance. In addition, a larger momentum coupling coefficient was obtained when plasma was propagated at a supersonic velocity. This is because supersonic plasma propagation forms a strong shock wave, resulting in an efficient pressure increase.
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Purazuma, Kaku Yugo Gakkai-Shi, 83(3), p.296 - 299, 2007/03
no abstracts in English
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Applied Physics, 100(11), p.113307_1 - 113307_4, 2006/12
Times Cited Count：72 Percentile：88.35(Physics, Applied)no abstracts in English
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Imai, Tsuyoshi*; Sakamoto, Keishi
Denki Gakkai Rombunshi, A, 126(8), p.807 - 812, 2006/08
Experiments on microwave plasma generation and its application to microwave beamed energy propulsion were conducted using a 1MW-class, 170GHz gyrotron. The microwave beam was focused using a parabola reflector and plasma was initiated near the focal point in the ambient air. Plasma propagated upstream in the microwave beam channel while absorbing microwave. Its propagation velocity was supersonic when the microwave power density was larger than 75kW/cm. The propulsive impulse was measured using a cone-cylinder shaped thruster model. As a result, maximum momentum coupling coefficient was obtained at a certain plasma propagation distance. In addition, large momentum coupling coefficient was obtained when plasma was propagated at a supersonic velocity. It would be because supersonic plasma propagation forms a strong shock wave, resulting in an efficient pressure increase.
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Proceedings of 42nd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 6 Pages, 2006/07
An experiment on microwave beaming propulsion with repetitive pulse was conducted. A millimeter-wave high power gyrotron developed in Japan Atomic Energy Research Institute was used for microwave generator. The velocity of plasma and shock wave propagation was measured. The velocity in the repetitive pulse condition was faster than that in the single pulse condition, and higher velocity was obtained at higher repetition rate due to the hot air remaining in the thruster.
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Proceedings of 25th International Symposium on Space Technology and Science (ISTS-25) (CD-ROM), p.177 - 181, 2006/06
The thrust generation model of a pulse detonation engine (PDE) was applied to a microwave beaming thruster composed of a cylindrical tube, because an ionization front propagates in the tube absorbing microwave power following a shock wave. Total impulsive thrust was estimated by integrating the pressure history at the thrust wall. The thrust for a thruster with the tube length of 
= 0.18m was 0.16Ns. It was twice as large as that measured in the flight experiment. This discrepancy would be caused during the air-refilling process. Pressure histories under multi pulse operation were also measured at the frequency from 40Hz to 15Hz. The shock velocity and pressure in the thruster changed with the pulse repetition frequency. Although impulsive thrust was decreased with pulse repetition frequency, the decrease in thrust at the frequency lower than 20Hz was allowably small.
Oda, Yasuhisa*; Shibata, Teppei*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Journal of Space Technology and Science, 22(2), p.30 - 37, 2006/00
A thrust generation model for microwave rocket was studied. The model was based on shock wave propagation driven by atmospheric plasma as analogy of pulse detonation engine (PDE). Pressure histories in the thruster were measured using pressure gauges and compared to the model. The shock wave was measured from pressure history in the thruster model. The relationship between the shock-wave traveling time and propagation distance showed good linearity. At the same time, the propagation velocity of the ionization front in the tube was also measured. The velocity is also nearly constant during the propagation. The both velocities were increased with the power density. The both the ionization front and the shock wave propagated at the same velocity when they propagated at supersonic speed. Thrust impulse was estimated from pressure history. Estimated thrust showed good agreement to the result of the flight experiment.
Oda, Yasuhisa*; Ushio, Masato*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
AIP Conference Proceedings 766, p.297 - 302, 2005/04
no abstracts in English
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Denki Gakkai Kenkyukai Shiryo, Genshiryoku Kenkyukai (NE-04-11
15), p.19 - 22, 2004/09
no abstracts in English
Nakagawa, Tatsuo*; Mihara, Yorichika*; Komurasaki, Kimiya*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi
Journal of Spacecraft and Rockets, 41(1), p.151 - 153, 2004/02
Times Cited Count：41 Percentile：88.10(Engineering, Aerospace)A launching experiment of a microwave-boosted vehicle model was carried out using the 110GHz, 1MW gyrotoron and a propulsive inpulse to lift up the vehicle was measured. The rf power and pulse was 1MW and 0.175 0.8msec. The launching mechanism is as follows. Plasma is produced in the nozzle of the vehicle model when the rf beam is injected toward it. The plasma heated by the rf beam can produce a shock wave that gives a propulsive impulse to the vehicle. Maximum momentum coupling coefficient from the impulse to the vehicle is 395N/MW which is comparable to that of a laser boosted vehicle. The rf pulse was 0.175msec. The coupling coefficient is limitted by the gyrtron operation in pulse length and can increase if the pulse length is shorter than 0.175msec.
Oda, Yasuhisa*; Nakagawa, Tatsuo*; Matsui, Makoto*; Komurasaki, Kimiya*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi
Dai-47-Kai Uchu Kagaku Gijutsu Rengo Koenkai Koenshu (CD-ROM), p.1067 - 1069, 2003/00
no abstracts in English
Matsui, Makoto*; Mihara, Yorichika*; Nakagawa, Tatsuo*; Mori, Koichi*; Komurasaki, Kimiya*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi
Uchu Yuso Shimpojiumu (Heisei-14-Nendo) Koenshu, p.300 - 303, 2003/00
no abstracts in English
Shibata, Teppei*; Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
no journal, ,
no abstracts in English
