Japan Aerospace Exploration Agency

Nec Corporation

Kasuga Denki, Inc.

Hitoshi Kuninaka

Hiroshi Iida

Nobuo Nomura

Satoshi Hosoda

Takato Morishita

Yasuo Horiuchi

Kyoichi Kuriki

Kazuki Minemura

Tomofumi Mogami

Daiki Koda

Yoshiki Yamagiwa

In a microwave plasma source, a tubular magnet portion has a first opening end and a second opening end. The first opening end has a first polarity, and the second opening end has a second polarity. The tubular body is surrounded by the tubular magnet portion. A first magnetic circuit portion closes the first opening end. A second magnetic circuit portion is disposed opposite to the first magnetic circuit portion. The second magnetic circuit portion has a first opening part. An antenna penetrates the first magnetic circuit portion, is introduced to a space, and supplies microwave power to the space. The nozzle portion has a second opening part that has a smaller opening area than the first opening part and communicates with the first opening part. When an inner diameter of the tubular body is represented by a (mm), and a microwave cutoff wavelength of the microwave power being supplied to the space is represented by &#x3bb; (mm), the microwave plasma source is configured to satisfy a relational expression &#x3bb;&#x3e;3.41&#xd7;(a/2).

Microwave plasma source

A charge neutralizer that includes a vacuum chamber which is capable of having a charged object installed therein and includes a high vacuum processing unit that performs vapor deposition, and a plasma generator configured to supply plasma caused by an electron cyclotron resonance to an inside of the vacuum chamber. The plasma generator includes a plasma source configured to generate the plasma, and a flange configured to install the plasma source inside the vacuum chamber.

Charge neutralizer and plasma generator

Disclosed is a space propulsion device capable of continuous operation using a solid propellant having high density and excellent handleability. The solid propellant-based space propulsion device comprises solid-propellant support means for supporting a solid propellant, a solid-propellant attachment surface for permitting the solid propellant to be attached thereon, solid-propellant feed means for feeding the solid propellant to an attachment position on the solid-propellant attachment surface, adhesion-energy supply means for heatingly melting or sublimating the solid propellant in the attachment position to adherently attach the solid propellant onto the solid-propellant attachment surface, solid-propellant transfer means for transferring the solid propellant to a release position for releasing the solid propellant, and propulsive-energy supply means for energizing the transferred solid propellant to release the solid propellant from the solid-propellant attachment surface at the release position, as a propulsive jet, while accelerating the solid propellant in a direction approximately perpendicular to the solid-propellant attachment surface. The solid-propellant transfer means is designed to move the solid-propellant attachment surface in such a manner that a area of the solid-propellant attachment surface for adherently holding the solid propellant is returned to a position adjacent to an end of the solid propellant in a repetitive manner.

Solid propellant-based space propulsion device

Disclosed is a high-frequency discharge plasma generation-based two-stage Hall-effect plasma accelerator, which comprises an annular acceleration channel having a gas inlet port, a high-frequency wave supply section, an anode, a cathode, a neutralizing electron generation portion and a magnetic-field generation element, wherein: gas introduced from the gas inlet port into the annular acceleration channel is ionized by a high-frequency wave supplied from the high-frequency wave supply section, to generate plasma; a positive ion includes in the generated plasma is accelerated by an acceleration voltage applied between the anode and cathode, and ejected outside; and an electron included in the generated plasma is restricted in its movement in the axial direction of the annular acceleration channel by an interaction with a magnetic field. The two-stage Hall-effect plasma accelerator is designed to control a degree of ion acceleration in accordance with the acceleration voltage serving as an acceleration control parameter, and control an amount of plasma generation in accordance with the high-frequency wave output serving as a plasma-generation control parameter. The two-stage Hall-effect plasma accelerator of the present invention can control the ion acceleration and the plasma generation in a highly independent manner.

Two-stage hall effect plasma accelerator including plasma source driven by high-frequency discharge

Ion particles are discharged so as to be influenced by a magnetic field originated from the earth, and collided with high-altitude neutral air to generate high velocity neutral particles through charge exchange. The high velocity neutral particles are analyzed. The distance to the high-altitude neutral air from at least one of the discharging positions of the ion particles and the measured positions of the high velocity neutral particles is determined based upon the period of time between the discharging time of the ion particles and the time the high velocity neutral particles are analyzed. Moreover, the direction of the high-altitude neutral air is determined by measuring the direction of the high velocity neutral particles. In addition, the spatial position of the high-altitude neutral air is determined based upon the measured direction of the high velocity neutral particles.

Method for observing high-altitude neutral air and device for observing high-altitude neutral air

In a solar photovoltaic power generation device comprising a plurality of power generation units (31-34) each of which comprises first through n-th generation elements, the first through the n-th generation elements are connected in parallel and have their polarity directed in the same direction. The plurality of power generation units are arranged so that adjacent power generation units have polarities which are opposite to each other. Each of the plurality of power generation units further comprises a plurality of switch elements, each of which has active and inactive states, for connecting the first through the n-th generation elements in series in the active state. The solar photovoltaic power generation device further comprises a power control unit (37) for controlling the plurality of switch elements for placing it into the active state in each of the plurality of power generation units.

Solar photovoltaic power generation device capable of adjusting voltage

An ion thruster is operable in an interplanetary space with plasma generated by microwaves in a propellant atmosphere. A vessel defines first, second and third hollow spaces and a window between the first hollow space and the second and third hollow spaces, the second hollow space having an opening. A microwave generating unit generates the microwave in the first hollow space as a standing wave penetrating into the second and thid spacers hollow. A propellant supplying unit supplies the propellant into the second and third hollow spaces, the propellant serving as a main and neutralizing propellant and absorbing the standing wave to produce main plasma comprising main ions and main elecrons. An accelerating unit accelerates only the main ions into an ion beam to inject the ion beam through the opening into the interplanetary space. A neutralizing unit defines a third space which is in communication to the first space and into which the standing wave penetrates. The propellant comes into the third space to produce neutralizing ions and electrons. The ions are pulled by the ion beam to leave the neutralizing electrons, which neutralize the vessel.

Growing community of inventors

Tokyo, Japan

Hitoshi Kuninaka