Study on the influence of the magnetic field geometry on the power deposition in a helicon plasma source

2019 ◽  
Vol 85 (4) ◽  
Author(s):  
M. Magarotto ◽  
D. Melazzi ◽  
D. Pavarin
Keyword(s):  
Magnetic Field ◽  
Power Spectrum ◽  
Three Dimensional ◽  
Plasma Source ◽  
Magnetostatic Field ◽  
Helicon Plasma ◽  
Power Deposition ◽  
Full Wave ◽  
Field Geometry ◽  
Helicon Source

We have numerically studied how an actual confinement magnetostatic field affects power deposition in a helicon source. We have solved the wave propagation by means of two electromagnetic solvers, namely: (i) plaSma Padova Inhomogeneous Radial Electromagnetic solver (SPIREs), a mono-dimensional finite-difference frequency-domain code, and (ii) Advanced coDe for Anisotropic Media and ANTennas (ADAMANT), a full-wave three-dimensional tool based on the method of moments. We have computed the deposited power spectrum with SPIREs, power deposition profile with ADAMANT and the antenna impedance with both codes. First we have verified the numerical accuracy of both SPIREs and ADAMNT. Then, we have analysed two configurations of magnetostatic field, namely produced by Maxwell coils, and Helmholtz coils. For each configuration we have studied three cases: (i) low density $n=10^{17}~\text{m}^{-3}$ and low magnetic field $B_{0}=250$  G; (ii) medium density $n=10^{18}~\text{m}^{-3}$ and medium magnetic field $B_{0}=500$  G; (iii) high density $n=10^{19}~\text{m}^{-3}$ and high magnetic field $B_{0}=1000$  G. We have found that the Maxwell coil configuration does not produces significant changes in the deposited power phenomenon with respect to a perfectly uniform and axial magnetostatic field. While the Helmholtz coil configuration can lead to a power spectrum peaked near the axis of the discharge.

scholarly journals Studies of the helicon plasma source with inhomogeneous magnetic field

2016 ◽  
Author(s):  
I. V. Shikhvotsev ◽  
V. I. Davydenko ◽  
A. A. Ivanov ◽  
I. A. Kotelnikov ◽  
E. I. Kuzmin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Plasma Source ◽  
Inhomogeneous Magnetic Field ◽  
Helicon Plasma

On the existence of transverse MHD oscillations in an inhomogeneous magnetoplasma

1990 ◽  
Vol 43 (1) ◽  
pp. 83-99 ◽  
Author(s):  
Andrew N. Wright
Keyword(s):  
Magnetic Field ◽  
Three Dimensional ◽  
Background Field ◽  
Alfven Wave ◽  
Field Perturbation ◽  
Independent Field ◽  
Background Magnetic Field ◽  
Field Geometry ◽  
Divergence Free ◽  
Field Lines

In a cold plasma with no compressional field perturbation the equations governing the two perpendicular components of magnetic-field perturbation decouple. These two equations depend only upon spatial derivatives along the background magnetic field, and give the impression of independent field-line motion in the two transverse directions. However, the perturbation magnetic field b must be divergence-free. It is not meaningful to ask if the field perturbation on an individual background line of force satisfies ∇. b = 0. To decide whether b is divergence-free, we need to know about its spatial variation, i.e. what the state of the neighbouring field lines is. In this paper we investigate two classes of solutions: first we allow the perturbation magnetic flux to satisfy ∇. b = 0 by threading across the background lines of force; the second solution closes b by allowing the perturbation flux to encircle the background field lines (torsional Alfvén waves). For both of these solutions we study the relationship between neighbouring field lines, and are able to derive a set of criteria that the background medium must satisfy. For both classes we find restrictions upon the background magnetic-field geometry - the first class also has a constraint upon the plasma density. The introduction of perfectly conducting massive boundaries is also considered, and a relation given that they must satisfy if the field perturbation is to remain transverse. The criteria are presented in such a manner that it is easy to test if a given medium will be able to support the solutions described above. For example, a three-dimensional dipolo geometry is able to carry oscillatory toroidal fields; but not purely poloidal ones or a torsional Alfvén wave.

scholarly journals Development and Verification of Material Plasma Exposure Concepts

2020 ◽  
Vol 9 (03) ◽  
pp. 11-14
Author(s):  
Dr. Avinash Pawar
Keyword(s):  
Plasma Generator ◽  
Plasma Source ◽  
Plasma Exposure ◽  
Helicon Plasma ◽  
Nuclear Science ◽  
Helicon Source ◽  
Surface Examination

The accessibility of future combination gadgets, for example, a Fusion Nuclear Science Facility incredibly relies upon long working lifetimes of plasma confronting segments in their diverters. Material-Plasma Exposure will use another high-force plasma source idea dependent RF innovation. This spring idea permit test to swathe the whole ordinary plasma surroundings in the diverter of a hope combination reactor. The option to examine disintegration and re-affidavit for pertinent calculations with applicable thrilling and attractive fields before the objective. Material-Plasma Exposure is being intended to take into consideration the presentation of from the earlier neutron-lighted examples. The objective exchange container has been intended to straight plasma generator with the end goal that it very well may be moved to posting for more itemized surface examination. Material-Plasma Exposure is being created in an arranged methodology with progressively expanded abilities. After the underlying improvement stride of the helicon source and the source idea is being tried in the Proto-Material-Plasma Exposure gadget. First warming with microwaves brought about a superior ionization spoke to by privileged electron solidity on pivot, when contrasted with the helicon plasma just without warming.  

Multiple characteristics of three‐dimensional radiative Cross fluid with velocity slip and inclined magnetic field over a stretching sheet

Heat Transfer ◽  
2021 ◽  
Author(s):  
Hafiz Abdul Wahab ◽  
Syed Zahir Hussain Shah ◽  
Assad Ayub ◽  
Zulqurnain Sabir ◽  
Muhammad Bilal ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Stretching Sheet ◽  
Three Dimensional ◽  
Velocity Slip ◽  
Inclined Magnetic Field ◽  
Multiple Characteristics

scholarly journals The first observation of 4D tomography measurement of plasma structures and fluctuations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chanho Moon ◽  
Kotaro Yamasaki ◽  
Yoshihiko Nagashima ◽  
Shigeru Inagaki ◽  
Takeshi Ido ◽  
...  
Keyword(s):  
Steady State ◽  
Three Dimensional ◽  
Axial Direction ◽  
Axial Position ◽  
Entire Cross Section ◽  
Helicon Plasma ◽  
Emission Profile ◽  
Dimensional Measurement ◽  
Tomography System ◽  
Three Dimensional Measurement

AbstractA tomography system is installed as one of the diagnostics of new age to examine the three-dimensional characteristics of structure and dynamics including fluctuations of a linear magnetized helicon plasma. The system is composed of three sets of tomography components located at different axial positions. Each tomography component can measure the two-dimensional emission profile over the entire cross-section of plasma at different axial positions in a sufficient temporal scale to detect the fluctuations. The four-dimensional measurement including time and space successfully obtains the following three results that have never been found without three-dimensional measurement: (1) in the production phase, the plasma front propagates from the antenna toward the end plate with an ion acoustic velocity. (2) In the steady state, the plasma emission profile is inhomogeneous, and decreases along the axial direction in the presence of the azimuthal asymmetry. Furthermore, (3) in the steady state, the fluctuations should originate from a particular axial position located downward from the helicon antenna.

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