Calculation and measurement of electron emission current on plasma generator tube for pulse electron irradiator

¹ Research Center for Accelerator Technology, Nuclear Energy Research Organization (ORTN), National Research and Innovation Agency (BRIN), Yogyakarta, Indonesia
² Department of Nuclear Engineering and Engineering Physics, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Calculation and measurement of electron emission current in Plasma Generator Tube (PGT) specifically for electron pulse irradiation have been performed. At an electron density of ne = 10¹⁷ m⁻³, a plasma temperature of Te = 7 eV, and an arc discharge current Id = 80 A (pulse width τ = 100 µs), the measurement and calculation show that the electron emission current is 29.4 A and 29.8 A, respectively, in the form of pulses. Because the current is alternating and pulsed, it can directly enter the first cavity in a linear accelerator (Linac) experiment. As a result, the current has passed through the grid and may replace the electron collector. On the surface of the PGT coated with a square SS grid/mesh, the emission window area measures (600×15) mm² with a grid radius of 0.3 mm and a grid spacing of 0.25 mm. In addition to contributing to plasma characteristics, the grid hole size also affects the electron emission current Ie. The PGT grid holes are best square in shape and size with a side length of p ≈ 0.5 mm. The electron emission current is influenced by the plasma properties as well as the grid hole size. The optimal grid hole size and shape for PGT is one with a grid radius of re = 0.3 mm.