Optical emission spectroscopy for plasma diagnosis of 2.45 GHz ECR ion source at Peking University

A quartz-chamber 2.45 GHz ECR ion source is designed at Peking University (PKU) for the application of plasma diagnosis [Patent Number: ZL 201110026605.4]. In this work, spectra of this ion source, which operate under different gas pressure and different RF power, are acquired with a high resolution spectrometer. The collision radiative (CR) model and line intensity ratio method are chosen for the plasma parameters diagnosis inside the discharge chamber during the plasma generation processes. The electron temperature and electron density are obtained based on the line ratio of noble gas. The dissociation degree of hydrogen is measured with the line ratio of hydrogen. At last, the plasma processes are discussed based on the diagnostic results and the performance of the cluster ion source at PKU.