著者

中島 秀紀 立園 恵巳子 神田 幸則

出版者

九州大学大学院総合理工学研究科

雑誌

九州大学大学院総合理工学報告 (ISSN:03881717)

巻号頁・発行日

vol.14, no.3, pp.329-336, 1992-12-01

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A recent model by Kammash and Galbraith (Nuc1. Fusion 29 (1989) 1079) for the energy gain calculation of the Magnetically Insulated Inertial Confinement Fusion (MICF) pellet has employed an incorrect expression for the equation of motion. Use of the correct expression can substantially change the prediction by the model. The input energy may require, at least, an order of magnitude increment to obtain the energy gain factor Q values in the hundreds.

著者

桑野 寛久 國中 均 中島 秀紀

出版者

一般社団法人 日本航空宇宙学会

雑誌

日本航空宇宙学会論文集 (ISSN:13446460)

巻号頁・発行日

vol.55, no.639, pp.188-194, 2007 (Released:2007-05-10)

参考文献数

10

被引用文献数

2 2

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Microwave discharge Hall thruster can be operated by two operating modes. The first one is “no microwave launching” mode, thus having the thruster operating as single-stage type. The other mode is “microwave launching” mode, thus having the thruster operating as double-stage type. In order to examine the influence of microwave launching mode upon the plasma condition inside the acceleration channel, as well as the relationships between thruster perform­ance and acceleration channel length, single-probe measurements and ion beam energy diagnostics in the plume were carried out. Single-probe measurements revealed the existence of dense plasma and high electron temperature region in the acceleration channel upstream due to the heating of the electrons by microwave. The variation in the discharge current characteristic due to the difference in acceleration channel length was not significant. As for discharge current, double-stage operation always results in a lower value compared to the value at the single-stage operation. Ion beam current was always higher at double-stage operation compared to the value at single-stage operation. Voltage utilization efficiency has improved as the channel length became short with microwave launching.

著者

平野 賢治 豊田 裕司 木邊 厚視 山本 直嗣 中島 秀紀

出版者

九州大学大学院総合理工学府

雑誌

九州大学大学院総合理工学報告 (ISSN:13467883)

巻号頁・発行日

vol.35, no.1, pp.1-5, 2013-09

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The abundance ratio of the doubly charged ions in an ion thruster plume was measured in order to estimate the thrust and validate a numerical simulation code for lifetime validation of ion thruster. An E×B probe was used for the estimation of the ratio of doubly charged ions to singly charged ions. The ratio of doubly charged ions to singly charged ions is 0.04 at an incident microwave power of 8 W and a mass flow rate of 20 μg/s. The ratio is decreased with increase in mass flow rate. This is because the increase in mass flow rate leads to the decrease in mean free path, and electrons get less energy from the microwaves. The E×B probe can estimate the ion velocity and the average velocity of the accelerated ions is estimated as 3.7×10^4 m/s at a screen voltage of 1000 V, which is reasonable compared to the theoretical value.

著者

林 真照 渡辺 幸信 加来 大輔 中島 秀紀 相良 建至

出版者

九州大学大学院総合理工学府

雑誌

九州大学大学院総合理工学報告 (ISSN:13467883)

巻号頁・発行日

vol.27, no.3, pp.321-328, 2005-12

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We have investigated the response of a 6Li loaded neutron coincidence spectrometer to MeV neutrons. The spectrometer has a structure consisting of three 6Li-glass scintillators in a liquid organic scintillator BC-501A, which can detect selectively neutrons that deposit the full energy in the BC-501A using a coincidence signal generated from the capture event of thermalized neutrons in the 6Li-glass scintillators. The efficiency and response functions were measured using 4.7, 7.2 and 9.0 MeV mono-energetic neutrons, and were compared with those derived by combination with both neutron transport calculation in the spectrometer and scintillator response calculation. The calculation results showed fairly good agreement with the measured ones. Finally, the response function matrices were obtained for 1 to 10 MeV neutrons.