Papers by Keyword: Ion Source

Abstract: In constructing the low energy accelerator for plant modification the most important part is the ion source. In the conventional cold cathodes and hot filament ion source methods the filament continuously burns out over time, has a shorter lifespan and requires venting of the ion source to atmosphere. Henceforth the Radio frequency (RF) antenna ion source or “non-thermionic ion source” with 13.6 MHz was used in the accelerator as well as it being easy to generate varie the plasma souce and stability. This ion source can produce a particle beam of about ~30 to 40 mA current. The ion particle was extracted by the first zero voltage extraction rod electrode method focusing the ion beam of 0-30 kV with the second rod electrode after which the third rod electrode has zero voltage. In calculating and designing this system via the Simion8.0 Program, the result showed that the Ar⁺ ion beam with 30 keV can be focused with 1 cm diameter beam at the distance of 10 cm of the drift space.

Abstract: N-doped TiO2 films were prepared by using N ion beams to bombard TiO2 films surface. By controlling the metal ultrahigh vacuum gat valve, only the N ion beams working pressure was adjusted from 0.1 to 0.9 Pa, with the step size of 0.2 Pa. The composition, chemical bond structure, and optical properties of N-doped TiO2 films were investigated. The result indicated that with increasing the ion source working pressure, more N ions were generated and bombarded with the surface TiO2 films, which could result in more N ions were doped into the films. So with increasing the ion source working pressure from 0.1 to 0.9 Pa, the N/Ti and O/Ti atom ratio increased and decreased monotonously from 0.37 to 0.49 and 1.49 to 0.61, respectively. Meanwhile, because of more N doped into films, the mean absorbency of N doped TiO2 films in the visible range also increased monotonously from 4.8% to 45.8%.

Abstract: A new discharge system which can generate stable atmospheric pressure DC glow discharge is reported in this paper. The system is made up of an inner line electrode and an outer cylinder-like electrode. The radii of the inner and outer electrodes are only 0.08 and 2 mm, respectively. The transition from corona discharge to glow discharge is observed. The experiments show that the discharge has typical features of normal glow discharge and can produce nonthermal plasma. It has been used as an ambient ion source, and chemicals such as formic acid, acetic acid, phenol, and benzoic acid can be ionized well.

Abstract: Vacuum arc plasma can be formed using particularly uncomplicated hardware, providing a means for laboratory scale formation of dense and highly-ionized metal plasma. The simplicity and versatility of the approach has led to its widespread use in recent times for both fundamental and technological applications. When embodied in a plasma gun configuration, the source can provide a valuable tool for plasma deposition of metal and metal-containing thin films, including in plasma immersion configurations. When embodied in an ion source configuration, high current beams of metal ions can be formed, and such beams have found good use for ion implantation and particle accelerator injection. Here we briefly review vacuum arc plasma guns and ion sources, outlining some of the hardware embodiments that have been developed at Berkeley and used for various materials modification applications.