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Space-Charge Field Assisted Electron Acceleration by Plasma Wave in Magnetic Plasma Channel
Gupta, Devki Nandan,Kaur, Maninder,Gopal, Krishna,Suk, Hyyong IEEE 2016 IEEE transactions on plasma science Vol.44 No.11
<P>When the duration of a laser pulse is comparable to the plasma wave period, a large-amplitude plasma wave can be driven by the laser. In the presence of a guiding magnetic field, the large-amplitude plasma wave of finite transverse extent and large phase velocity resonantly accelerates the electrons to a higher energy level. For a small laser spot size, the laser exerts an axial as well as the radial ponderomotive force on the electrons that creates a density depression on the laser axis. This electron-depleted channel also creates a radial electric field ( ion space-charge field). The acceleration of electrons in this channel is investigated, where the effect of ion space-charge field is considered, by solving the single particle dynamical equations. This paper shows that the space charge field plays an important role in electron energy gain during acceleration by a plasma wave in a magnetic plasma channel. This paper may be crucial in understanding the dynamics of particle motion and improving the quality of accelerated electron beam in the laser wakefield accelerators.</P>
Mode-coupling assisted electron accelerations by a plasma wave
Devki Nandan Gupta,Krishna Gopal,Victor V. Kulagin,석희용 한국물리학회 2015 Current Applied Physics Vol.15 No.3
The acceleration of electrons by a plasma wave in the presence of density ripple in plasma has been investigated. Plasma density ripple can excite higher harmonics of different phase velocities of the fundamental plasma wave. The combined role of the different harmonics of the plasma wave contributes significantly in electrons energy gain during acceleration by the fundamental plasma wave. Our calculation shows that the plasma electrons gain considerable energy during the acceleration by the plasma waves in the presence of a density ripple in plasma. The initial electron energy and the ripple density play an important role for the acceleration of an electron.
Devki Nandan Gupta,Min Sup Hur,석희용 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.1
The combined role of an additional long-wavelength electromagnetic wave and a magnetic field on laser electron acceleration is examined. The electron dynamics and the energy gain in the presence of two electromagnetic waves of significantly different wavelengths are studied by using numerical calculations. The additional effect of an imposed magnetic field is also observed. According to this study, a short electromagnetic wave can accelerate the trapped electron to a high energy, and the external magnetic field bends the electron out of the laser path. Hence, the electron leaves the interaction region, so it does not lose energy anymore. As a result, in the proposed mechanism, the electron can gain a considerably high energy due to the effect of a magnetic field.