Development of a Radio Frequency Coupled Broad Beam Ion Source for Material Processing

Hassan, Amin; Gamal, Mohamed; Zakhary, Safwat; Osman, Lama; Hanafy, Magda

doi:10.21608/ajnsa.2018.2616.1038

Development of a Radio Frequency Coupled Broad Beam Ion Source for Material Processing

Document Type : Original Article

Authors

¹ Egyptian Atomic Energy Authority, NRC, Accelerators and Ion Sources Department

² Egyptian Atomic Energy Authority, NRC Accelerators and Ion Sources Department

³ Aswan University, Faculty of Science, Physics Department

⁴ Zagazig University, Faculty of Science, Physics Department

10.21608/ajnsa.2018.2616.1038

Abstract

The development of a radio frequency (RF) broad beam ion sources for generating a high brightness ion beams for material processing is presented. The source was able to deliver ion beams from 100 eV up to 2000 eV and with beam currents 100 µA up to 25 mA. The beams divergence do not exceed 7 degrees when using nominally flat grids. The current of ions extracted from a plasma source depends on the plasma parameters particularly the electron number density and electron temperature of the plasma. The Optical Emission Spectroscopy (OES) is employed to determine the plasma electron density and temperature. The effects of argon filling pressures and RF power on electron temperature and density plasma parameters are investigated. The electron density of Ar plasma is between 4x1011 cm-3 and 7x1012 cm-3 whereas electron temperatures 0.6 - 5 eV at pressures from 5x10-4 - 8.5 x10-3 mbar over the RF powers deposited within the plasma from 25 W to 200 W. The ion source is installed on a homemade accelerating tube. The beam optics is extensively studied with space charge compensation by TRANSPORT code. A solenoid magnet located between the ion source and the accelerating tube is used to focus and get the beam divergence under control. The performance of the accelerating facility is reported and applications for material modification is examined.

Keywords