Plasmas generated by electron beam passing through diamond window

Abstract

In this paper, we report the generation of Ar plasmas by using an electron beam passing through a diamond window. It is observed that plasma brightness varies with the electron beam energy and the duty cycle. The transmission properties of the electrons in a 5-μm-thick diamond film are investigated by both experiments and Monte Carlo simulation. The measured transmittance of the electron beam increases from 20% to 80% by increasing the incident energy of the electron beam on the diamond window from 32.5 keV to 50 keV. The diamond window was checked using a CCD camera and SEM after plasma generation experiments. It is found that the focused electron beam passes through the central region of the diamond window, from the incident plane to the exit plane, and the cross section of the diamond window gradually changes from textured morphology to a featureless structure, indicating that the main energy loss of electrons in the diamond window occurs in the later stage of the transmitting journey. The interaction between the electron and the diamond causes the structure change of the diamond. The simulated transmittances of the electron beam with respect to its incident energy are in agreement with the experimental results.