Purity of nitrogen ion beams produced in a plasma focus

Abstract

To improve the purity of ion beams produced in a plasma focus (PF), the dependence of the characteristics of the nitrogen ion beams on the shape of the anode was investigated. Two types of anodes, i.e. rod type (type A) and hollow type (type B) were used with a PF pre-filled with nitrogen gas. Thomson parabola spectrometer measurements showed the existence of a large amount of impurity ions, O 1-2+ , C + , and Cu 1-2+ , with nitrogen ions (N 1-3+ ) and the percentage of nitrogen ions is only 25% in type A. In contrast, in type B the impurity is extremely reduced and the percentage of nitrogen ions is enhanced to 91%. The maximum energies and power brightnesses of the nitrogen beams were evaluated to be 0.5 MeV and 0.23 GW cm −2 sr in type A and 1 MeV and 1.6 GW cm −2 sr in type B; hence, energy and brightness are also enhanced in type B. From x-ray pinhole images we see that strong electron irradiation occurs on the top of the anode in type A, whereas in type B, electron irradiation is weak and irradiation area is far from the pinch plasma. Hence, the impurity ions observed in type A are considered to be produced in the following process. Due to the strong irradiation of electrons on the anode top, the electrode and the absorbed gas on the electrode are vaporized, mixed with pinch plasma and accelerated with nitrogen ions.

Synthesis of nano-crystalline zirconium aluminium oxynitride (ZrAlON) composite films by dense plasma Focus device

“…This means that total number of ions and their energy hitting the substrate surface play a significant role to form different microstructures since the microstructure for different ion exposure shots is different. The evaluation of the surface microhardness (MPa) as a function of different imposed loads (10,25,50,100,200 and 300 g) for the samples exposed to multiple Focus shots (5, 10, 20, 30 and 40) is shown in Fig. 7.…”

“…soft/hard X-rays, neutrons, relativistic electrons and high current, high energy ion beams over a broad energy spectrum [10][11][12][13].…”

Role of charge particles irradiation on the deposition of AlN films using plasma focus device

“…In plasma focus device, different plasma/ionic species are generated due to different mechanisms/ processes at different regions which make the thin film growth mechanism a complex process. Firstly, there is nitrogen plasma of the filling gas species due to electric discharge through the ambient nitrogen gas which reaches very high temperatures (several hundreds of eV-keV) due to efficient compression and thus exists in multiple charged states [33,45]. The sausage instabilities are reported to result in acceleration of energetic ions (nitrogen ions in our case) and electrons.…”

Investigation of Effective Parameters on Metal Nitride Deposition by Plasma Focus Device: Number of Shots and Substrate Axial and Angular Positions

“…Plasma focus (PF) [1,2] method is a simple process that generates a magnetic field to compress the plasma to a high density of *10 25 -10 26 m -3 and high temperature (*1-2 keV) for a short period of time (*10 -7 s) [2,3]. This device is a potential candidate for soft and hard X-rays, neutrons, relativistic electrons and energetic ions irradiation [4,5]. These energetic ions have been utilized for different applications such as thin film deposition [6][7][8], thermal surface treatment [9], phase change of thin films [10] and ion implantation [11][12][13] in some studies.…”