Abstract
Herein, the extraction of high ion / electron current from an audio frequency (AF) nitrogen gas discharge (10 – 100 kHz) is studied and investigated. This system is featured by its small size (L= 20 cm and inner diameter = 3.4 cm) and its capacitive discharge electrodes inside the tube and its high discharge pressure ∼ 0.3 Torr, without the need of high vacuum system or magnetic fields. The extraction system of ion/electron current from the plasma is a very simple electrode that allows self-beam focusing by adjusting its position from the source exit. The working discharge conditions were applied at a frequency from 10 to 100 kHz, power from 50 – 500 W and the gap distance between the plasma meniscus surface and the extractor electrode extending from 3 to 13 mm. The extracted ion/ electron current is found mainly dependent on the discharge power, the extraction gap width and the frequency of the audio supply. SIMION 3D program version 7.0 package is used to generate a simulation of ion trajectories as a reference to compare and to optimize the experimental extraction beam from the present audio frequency plasma source using identical operational conditions. The focal point as well the beam diameter at the collector area is deduced. The simulations showed a respectable agreement with the experimental results all together provide the optimizing basis of the extraction electrode construction and its parameters for beam production.
Highlights
Plasma particles sources are characterized by its relief capability, which is limited by the amount of the particles released from the plasma boundary surface, and the extractor potential removal rate
The extraction characteristics study of the nitrogen gas discharge reveals that the type of the present plasma plays a substantial role to improve the extraction of both the ion and the electron beam
A high output beam current was measured on the collector at a distance of 10 cm from the plasma source
Summary
Plasma particles sources are characterized by its relief capability, which is limited by the amount of the particles released from the plasma boundary surface, and the extractor potential removal rate. Beams extraction depends on upon many limitations[1,2,3,4] such as geometry, extraction voltage applied, space charge of the extracted beam and the form of the plasma boundary exit side. Audio-Ultrasonic frequency (AF from 10 to 100 kHz) plasma source, generating adequate plasma in a simple design system and easy in operation characterizes the present plasma. Such system succeeded to reveal different amazing properties[5,6,7] exposing simple parameters spreading over particles extraction. It is important to study such AF plasma driven system to reveal maximum beam quality and minimum beam emittance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
