Document Type : Research

Abstract

In this paper, electron acceleration by a circularly polarized laser pulse in vacuum under the influence of constant magnetic field, combined constant axial and azimuthal magnetic fields and taper axial magnetic field has been studied. The effective parameters on energy gained by electron such as laser intensity, laser spot size, the value of azimuthal magnetic field and the tapered parameter of axial magnetic field are optimized. It was observed that by adding azimuthal magnetic field (about ) to constant axial magnetic field (about ) the maximum energy of electron can increase one and a half times (than the case of constant magnetic field) and reach to about . This is while tapered axial magnetic field with optimum tapered parameter    can keep the electron in acceleration phase for longer distance and reaches the electron to maximum energy about  with scattering angle about  degree.

Keywords

[1] Esarey E, Sprangle P, Krall J, Ting A. Overview of plasma-based accelerator concepts. IEEE Trans.Plasma Sci. 1996; 24: 252.
[2] Geddes C. G. R, Toth Cs, Tilborg J. van, Esarey E, Schroeder C. B, Bruhwiler D, Nieter C, Cary J, Leemans W. P. High-quality electron beams from a laser wakefield accelerator using plasma-channel guiding. Nature. 2004; 431: 538.
[3] Faure J, Glinec Y, Pukhov A, Kiselev S, Gordienko S, Lefebvre E, Rousseau J-P, Burgy F, Malka V. A laser-plasma accelerator producing monoenergetic electron beams. Nature. 2004; 431: 541.
[4] Leemans W. P, Nagler B, Gonsalves A. J, Toth Cs, Nakamura K, Geddes C. G. R, Esarey E, Schroeder C. B, Hooker S. M. GeV electron beams from a centimeter-scale channel guided laser wakefield accelerator. Nat. Phys. 2006; 2: 696.
[5] Tajima T, Dawson J. M. Laser Electron Accelerator. Phys. Rev. Lett. 1979; 43: 267.
[6] Chen P, Tajima T, Takahashi Y. Plasma Wakefield Acceleration for Ultrahigh-Energy Cosmic Rays. Phys. Rev. Lett. 2002; 89: 161101.
[7] Mora P, Quesnel B. Comment on Experimental Observation of Electrons Accelerated in Vacuum to Relativistic Energies by a High-Intensity Laser. Phys. Rev. Lett. 1998; 80: 1351.
[8] Wang P. X,  Ho Y. K, Yuan X. Q,  Kong Q,  Cao N, Shao L. Characteristics of   laser-driven electron acceleration in vacuum. J. Appl. Phys. 2002; 91: 856.
[9] Pang J, Ho Y K, Yuan X Q, Cao N, Kong Q, Wang P X, Shao L, Esarey E, Sessler A. M. Subluminous phase velocity of a focused laser beam and vacuum laser acceleration. Phys. Rev. E. 2002; 66: 06650.
[10] Sohbatzadeh F, Aku H. Polarization effect of a chirped Gaussian laser pulse on the electron bunch acceleration. J. Plasma Phys. 2011; 77: 39.
[11] Salamin Y.I, Mocken G.R, Keitel C.H. Electron scattering and acceleration by a tightly focused laser beam. Phys. Rev. STAccel.Beams. 2002; 5: 101301.
[12] Gupta D.N, Ryu C.M. Electron acceleration by a circularly polarized laser pulse in the presence of an obliquely incident magnetic field in vacuum. Phys. Plasmas. 2005; 12: 053103.
[13] Singh K.P. Acceleration of electrons by a circularly polarized laser pulse in the presence of an intense axial magnetic field in vacuum. J. Appl. Phys. 2006; 100: 044907.
[14] Ghotra H.S, Kant N. Electron acceleration to GeV energy by a chirped laser pulse in vacuum in the presence of azimuthal magnetic field. App. Phys. B. 2015; 120: 141.
[15] Sajal V, Tripathi V. K. Large amplitude lower hybrid wave driven by laser and its effect on electron acceleration in a magnetic plasma channel. Opt. Commun. 2008; 281: 3542.
[16] Gopal A, Minardi S, Burza M, Genoud G, Tzianaki I, Karmakar A, Gibbon P, Tatarakis M, Persson A, Wahlstrom C. G. MegaGauss magnetic field generation by ultra-short pulses at relativistic intensities. Plasma Phys. Control. Fusion. 2013; 55: 035002.
[17] Verdeyen Joseph T. Laser Electronics, Prentice-Hall, 1995; 3.
[18] Singh K. P, Malik H. K. Resonant enhancement of electron energy by frequency chirp during laser acceleration in an azimuthal magnetic field in a plasma. Laser Part. Beams. 2008; 26: 363.
[19] Batani D, Joachain C.J , Martellucci S, Chester A.N. Atoms, Solids and Plasmas in Super-Intense Laser Fields, Kluwer Academic/Plenum Publishers, New York. 2001.