Discharge and Emission Characteristics of Compact Corona-Plasma Cathode X-Ray Source

Abstract

Compared with the conventional cold cathodes, such as graphite, hacksaw blades, carbon felt or knife edges, the corona-plasma cathode has been found to be advantageous in vacuum discharge with regard to their lifetime and X-ray emission uniformity. In this paper, we present an experimental result on the characteristics of the flash X-ray source employing a corona-plasma cathode in the relatively low operating voltage range, 20-50kV. A simple, longlifetime and inexpensive corona-plasma cathode X-ray preionization source are achievable operating in low voltage range. We will study about both the discharge characteristics of the tube: (1) the characteristics of the discharge initiation and development, (2) the cross-sectional shape of electron beam, and (3) the velocities of the expanding plasma, and the operational characteristics of the X-ray source: (1) the dependence of X-ray output on both electrode separation and applied voltage, (2) X-ray spatial distribution, and (3) X-ray spectral distribution. These experimental results are also contrasted with a field-emission mode operated with same cathode.