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Decomposition of SF 6 by a low energy plasma focus (PF) device has been investigated. The PF device performance in SF 6 atmosphere was weaker than other gases such as argon, methane and nitrogen. Tungsten and vanadium anode tips were employed to generate thin layers of deposited products on substrates with different number of focused shots in SF 6 atmosphere. The proper choice of the anode tip and substrate material has a direct effect on SF 6 decomposition and generation of desire products. Free fluorine atoms and ions are produced during discharges that react with housing chamber and corrode the device materials such as Pyrex insulator, 304 stainless steel chamber and many more. Field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), grazing incidence X-ray diffraction (GIXRD) and X-ray photoelectron spectroscopy (XPS) were utilized to identify the deposited solid film products. • Reduction of SF 6 to solid fluorine and sulfur products. • Reduction of Al 2 O 3 to aluminum metal during SF 6 decomposition. • Stability of H x V 2 O 5 and reduction of V 2 O 3 during plasma processing in SF 6 atmosphere. • Effect of anode tip and substrate material on the synthesis of solid products during SF 6 decomposition. • Corrosion of components of plasma focus device by free fluorine atoms and ions. [ABSTRACT FROM AUTHOR]

Abstract: The motion of electrons moving along a helical undulator and interacting with each other through Lienard–Wiechert fields is considered. The numerical solution for initially mono-energetic electrons shows the emergence and growth of micro-bunching. For the case of initially non-mono-energetic electrons, calculations show that the presence of energy spread results in partial suppression of the micro-bunching. The calculations also show that the initial energy spread would shift the micro-bunching maximum to deeper positions within the undulator. Analytical treatment of equations of motion demonstrates that the micro-bunching fall and shift is mainly due to the random motion of the interacting electrons. [Copyright &y& Elsevier]

[Display omitted] • Synthesis of hydrocarbon-vanadium thin films by a low energy plasma focus device. • Formation of vanadium trioxide (V 2 O 3) and hydrogen vanadium bronze (H x V 2 O 5) structures. • Creation of C 26 H 22 O 3 V 2 molecular structure in nano-grain scale through interaction of H x V 2 O 5 with methane gas molecules. • Production of C 26 H 22 O 3 V 2 molecules as a "not Raman active" structure. Synthesis of hydrocarbon-vanadium thin films by a low energy plasma focus device is reported. The thin films have organometallic structure and organometallic trovacenyl carboxylic acid anhydride (C 26 H 22 O 3 V 2) is formed. The vanadium deposition process was achieved in methane atmosphere using different number (10, 20, and 30) of focused shots. Prior to deposition process, surface of pure vanadium substrate and the anode tip were exposed to atmosphere to allow the formation of vanadium trioxide (V 2 O 3) and hydrogen vanadium bronze (H x V 2 O 5) structures. During deposition process, H x V 2 O 5 reacts with methane molecules and C 26 H 22 O 3 V 2 molecular structure in nano-grain scale is created. The findings of present study indicates that C 26 H 22 O 3 V 2 can be categorized as a semiconductor with band gap energy in the range of 1.20–1.35 eV. Furthermore, it is demonstrated that C 26 H 22 O 3 V 2 molecular structure is not Raman active. Characteristics of the V 2 O 3 , H x V 2 O 5 and C 26 H 22 O 3 V 2 structures are investigated by crystalline, spectroscopy and microscopy methods. The average crystallite size of C 26 H 22 O 3 V 2 was roughly 6 nm with almost 16% carbon deposited in the thin films. The Raman results are independent of the number of focused shots. [ABSTRACT FROM AUTHOR]

Abstract: Plasma focus devices were studied in order to identify the design parameters and logical relationships that exist among device components. A quantitative parameter has been defined as the ratio of insulator sleeve length to the radial distance between the electrodes, “”. It is demonstrated that the Mather-type plasma focus device, operated in the optimum regimes, has a remarkably low sensitivity to this parameter which relates the insulator length to the electrodes geometry. A modification factor for the axial velocity in different PF devices has been introduced to maintain the value of the “q” parameter within the range of zero to one. [Copyright &y& Elsevier]