Modeling of electron cyclotron resonance acceleration in a stationary inhomogeneous magnetic field

Abstract

In this paper, the cyclotron autoresonance acceleration of electrons in a stationary inhomogeneous magnetic field is studied. The trajectory and energy of electrons are found through a numerical solution of the relativistic Newton-Lorentz equation by a finite difference method. The electrons move along a TE 112 cylinder cavity in a steady-state magnetic field whose axis coincides with the cavity axis. The magnetic field profile is such that it keeps the phase difference between the electric microwave field and the electron velocity vector within the acceleration phase band. The microwaves amplitude of 6 kV=cm is used for numerical calculations. It is shown that an electron with an initial longitudinal energy of 8 keV can be accelerated up to 260 keV by 2.45 GHz microwaves at a distance of 17 cm.

Cyclotron spatial autoresonance acceleration model

“…Now we proceed from the case B z ðzÞ ¼ B z ð0; zÞ which was studied in our previous work [13]. Using the values obtained in [13], the function bðz i Þ ¼ Bð0; z i Þ=B 0 À 1 was determined on the z axis in 81 points where the derivative dbðz i Þ=dz was found numerically.…”

“…Using the values obtained in [13], the function bðz i Þ ¼ Bð0; z i Þ=B 0 À 1 was determined on the z axis in 81 points where the derivative dbðz i Þ=dz was found numerically. The values bðzÞ and dbðzÞ=dz in the particle position points were calculated by using a linear interpolation method.…”

“…For the SARA concept, the diamagnetic force is one of the important factors limiting the energy which can be achieved. The analytical results were verified through numerical experiments under the conditions which were used in our previous SARA simulations [13].…”

“…Plasma heating by pulse microwaves in an adiabatic mirror magnetic trap observed in the experiments [12] was attributed to a cyclotron autoresonance interaction of electrons with microwaves. We have recently reported on the possibility of self-sustenance of the ECR conditions in the stationary inhomogeneous magnetic fields at a fixed microwave field frequency through a numerical solution of the relativistic Newton-Lorentz equation in the one-particle approximation [13]. This type of cyclotron resonance speeding up of electrons can be named as spatial autoresonance acceleration (or SARA).…”

Enhancement of electron energy during vacuum laser acceleration in an inhomogeneous magnetic field

“…One may enhance the cyclotron resonance acceleration by applying a time-varying magnetic field 24,25 or a stationary inhomogeneous magnetic field. [26][27][28][29] In Ref. 26, the electron cyclotron resonance acceleration by an intense plane-wave laser pulse has been investigated.…”