Development and characterization of a helicon plasma source

Abstract

The Helicon Plasma Source (HeliPS) designed and developed at the Centre of Plasma Physics-Institute for Plasma Research is a versatile helicon plasma device, which operates in a wide range of magnetic field configurations from 50 G to 500 G. This device is dedicated to perform a broad range of research activities. The main objective for development of the HeliPS is to carry out studies on ion-ion plasmas in electronegative gases. In the near future, ion-ion plasmas will be formed in electronegative gases in the downstream of the plasma production region. Although the system is primarily designed to carry out ion-ion plasma experiments, the same system can also be used for experimental studies on some basic helicon plasma properties such as wave propagation, wave coupling, and plasma instability. At present, argon plasma is produced with a RF power supply of 13.56 MHz frequency. External circuit parameters, such as antenna current, plasma resistance (R), and internal parameters, such as electron density and temperature, are measured. The details of the experimental setup development, device characteristic, as well as preliminary plasma production and characterization to confirm occurrence of the helicon plasma in the system are presented in this article.

Effect of neutral pressure on the blue core in Ar helicon plasma under an inhomogeneous magnetic field

“…Pictures were taken above 200 W RF power, the threshold to achieve a helicon plasma regime. The magnet was installed in the upper part of the discharge tube following the biggest value of the magnetic field (∼400 G) located upstream, which made the upper position produce a higher plasma density [3,19]. The brightest emissions are observed in the antenna region at the lowest pressure of 0.08 Pa.…”

“…Among them, the magnetic field is one of the most important factors. Under certain conditions, the plasma density is proportional to the magnetic field [15][16][17][18][19], except for the low field peak phenomenon [3,20,21]. Based on the results of experiments and simulations, Guo et al [22] deduced that the helicon wave absorption is enhanced when the density gradient in the axial direction is comparable to the axial magnetic field gradient.…”

Comparison of heating mechanisms of argon helicon plasma in different wave modes with and without blue core

“…Helicon plasmas have attracted great attention in applications of material processing, surface treatment and electric thrusters due to their high ionization rate and high plasma density [1][2][3][4]. Most researches in helicon plasma sources have been carried out in a wide range of electron density from 10 10 to 10 14 cm −3 under relatively low external magnetic fields (0.1 mT-0.1 T) and radio-frequency (RF) power (1-5 kW) [5][6][7][8]. For ion heating in large linear devices, helicon plasma sources were also studied under higher magnetic fields (0.1-5 T) and higher RF powers (10-100 kW) [9][10][11][12].…”

“…the total electron collision frequency with ions ν e-i and neutrals ν m ). Using equations(5) and (8) to eliminate j  and E ,  one can obtain…”

Study on negative ion production by electronegative gases in a helicon source

“…11) After design and development of the system, characterization of the system is done and the transition to the helicon mode is established by various experiments. 12) With electronegative gases, HeliPS can produce electronegative plasma where positive ions and negative ions co-exist along with the electrons and background neutral gas molecules. We have used usual electropositive argon gas as the working gas together with the electronegative gases hydrogen and oxygen in the experiment.…”