Development of large volume double ring penning plasma discharge source for efficient light emissions

Abstract

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd(2)Fe(14)B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ~0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ~2 × 10(11) cm(-3), which is around one order of magnitude larger than that of single ring arrangement.

Effect of magnetic field on the hysteresis phenomena and floating potential oscillations in a reflex plasma source

“…Hence, the discharge is dominated by negative space charge. The simulation study for this type of electrode geometry shows electron space charge in the anode ring 19 . This negative space charge acts as a potential barrier to low energy electrons while free fall for ions.…”

Observation of multiply charged states ions in a high-power pulsed reflex discharge

“…The optical plasma emission of the stationary coldcathode reflex discharge was investigated by the optical emission spectroscopy (OES) method, e.g. see [6][7][8][9][10][11][12][13]. The line spectrum of the plasma gaseous component in different spectral ranges was investigated in both pure gases H 2 [6][7][8], N 2 and O 2 [8], He [8][9][10][11][12], Ne [8], Ar [8], and gas mixtures, e.g.…”

“…see [6][7][8][9][10][11][12][13]. The line spectrum of the plasma gaseous component in different spectral ranges was investigated in both pure gases H 2 [6][7][8], N 2 and O 2 [8], He [8][9][10][11][12], Ne [8], Ar [8], and gas mixtures, e.g. He+Ne+Ar [12].…”

“…This is achieved by optimizing the design of the ion source and choosing a discharge mode. Therefore, the experimental results obtained in ion sources are rather difficult to compare with the results of other studies where the goal was not to obtain multiply charged ions, for example, [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][28][29][30][31][32].…”