Particle-in-cell Simulation of Processes in the Electron Gas

Authors I.I. Nikishkin, R.I. Kholodov

The Institute of Applied Physics, N.A.S. of Ukraine, 58, Petropavlivska St., 40000 Sumy, Ukraine

Issue Volume 13, Year 2021, Number 5
Dates Received 29 July 2021; revised manuscript received 20 October 2021; published online 25 October 2021
Citation I.I. Nikishkin, R.I. Kholodov, J. Nano- Electron. Phys. 13 No 5, 05022 (2021)
PACS Number(s) 41.20.Cv, 52.35.Fp, 52.65.Rr
Keywords Particle-in-cell, Kinetics, Plasma (13) , Natural oscillations, Simulation (34) .

Elementary interaction processes of charged particles in an electron beam with a current of about 1 A are studied numerically concerning the electron cooling problem. A one-dimensional particle-in-cell code is used to consider the following processes: expansion of the free electron gas, temperature equalization in the electron gas, natural oscillations in quasi electron-positron and electron-proton gases. In this method, the free electron gas expands due to electrostatic repulsion between electrons at a constant total energy. The model of a free electron gas represented by computational particles in the form of endless plates is also solved analytically. In this case, the velocity deviation as a function of time and the distance between the charge centers of the two halves of the electron gas are found analytically. And this is compared with the result of the numerical calculation. If the electron gas is represented as two subsystems with different temperatures, this leads to temperature equalization in the simulation. The paper considers several cases with different initial temperature conditions and finds the relaxation time. The simulation result of electron-positron and electron-proton gases shows that their oscillations are accompanied by Landau damping. The spectral frequency distribution of these oscillations shows the maxima that correspond to theoretical estimates.

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