Effects of Axial Magnetic Field and Faraday Shield on Characteristics of RF Produced Plasma Using Spiral Antenna

AEROSPACE TECHNOLOGY JAPAN

Shinohara

Ishii

et al. 2016

Self Cite

We have been studying long-lifetime helicon plasma thrusters as the Helicon Electrodeless Advanced Thruster (HEAT) project. Two important elements of the proposed helicon plasma thruster are a generation of a dense source plasma using a helicon wave, and an acceleration of the plasma by the Lorentz force using the product of the induced azimuthal current and static radial magnetic field. Here, in order to eliminate damage of electrodes, both generation and acceleration schemes are operated in non-contact condition between the plasma and electrodes. Acceleration schemes use two type of coils: rotating magnetic field coils and azimuthal mode number m = 0 ones. These studies have been carried out on the Large Mirror Device (LMD), which has two types the magnetic field source, permanent magnets and electromagnets, and the Small Helicon Device (SHD), which has small diameter discharge tubes. In this paper, current performances of acceleration schemes are reported.

Section: Introductionmentioning

confidence: 99%

High-Density Helicon Plasma Thrusters Using Electrodeless Acceleration Schemes

AEROSPACE TECHNOLOGY JAPAN

Shinohara

Ishii

et al. 2016

Self Cite

“…Additionally, relative density can be obtained from the area of IVDF. Figure 2 shows the LIF measurement system on Large Mirror Device (LMD), 22) and Table 1 shows specifications and operating conditions of this device. The LMD has a tapered quartz tube connected to a main chamber.…”

Section: Lif Schemementioning

confidence: 99%

Spatial Profile of Ion Velocity Distribution Function in Helicon High-Density Plasma by Laser Induced Fluorescence Method

Tanida

AEROSPACE TECHNOLOGY JAPAN

Shinohara

2016

Self Cite

Helicon plasma sources have been studied in many fields across science and technology because they can supply high-density plasmas with a broad range of external operating parameters. In our laboratory, we aim to develop a completely electrodeless electric thruster, which is expected to have a high efficiency and a long lifetime, leading to be useful on a deep space exploration. In order to demonstrate and optimize this thruster system, it is important to have detailed distributions of plasma flow. Laser induced fluorescence (LIF) diagnostics, which can measure velocity distribution functions of particles, has advantages from a view point of, e.g., high resolution in time and space, and it can determine an absolute particle velocity and its temperature in addition to its relative density. Here, we have been developing a LIF measurement system using a Multi-Pixel Photon Counter (MPPC) for a multi-channel system. Argon ion velocity depending on the magnetic field gradient in a downstream region is measured by this LIF system.

“…mum of its Doppler spectrum, m the particle mass, and k B the Boltzmann constant. Figure 2 shows a schematic diagram of Large Mirror Device (LMD) [9]. A quartz discharge tube [1,000 mm in length and 100 ∼ 170 mm in inner diameter (i.d.)]…”

Section: Principle Of Lif Measurementmentioning

confidence: 99%

Development of Ar I and Ar II Measuring System using Laser-Induced Fluorescence Methods in High-Density Helicon Plasma

Plasma and Fusion Research

Tanida

Watanabe

et al. 2015

Self Cite

A particle flow velocity measurement is important to realize a behavior of exhausted plasma in an electric thruster. Laser-induced fluorescence (LIF) method provides flow velocities of ions and neutral particles through measuring velocity distribution functions of them. In addition, LIF method has some advantages, shown as follows; 1) high-spatial resolution, 2) absolute measurement of flow velocity, 3) direction-selectivity of velocity distribution functions. We have developed Ar I and Ar II LIF measuring system to observe spatial profiles of velocity distribution functions of both neutral particles and ions in an experimental device of the helicon plasma thruster, having permanent magnets as the applied magnetic field. Flow velocity of the neutral particle in the axial direction was subsonic, and ion velocity was related with a gradient of the magnetic field.