Excitation of ion wakefields by electromagnetic pulses in dense plasmas

Abstract

Abstract. The excitation of electrostatic ion wakefields by electromagnetic pulses in a very dense plasma is considered. For this purpose, a wave equation for the ion wakefield in the presence of the ponderomotive force of the electromagnetic waves is obtained. Choosing a typical profile for the electromagnetic pulse, the form of the ion wakefields is deduced. The electromagnetic wave-generated ion wakefields can trap protons and accelerate them to high energies in dense plasmas.There are many proposals [1][2][3][4][5] for exciting high-phase speed intense electrostatic wakefields by electron bunches and laser beams in an unmagnetized electron-ion plasma [2,4,5]. Large-amplitude electron plasma waves are capable of accelerating electrons to extremely high energies, as demonstrated experimentally [6][7][8][9][10][11][12][13][14]. Possible applications of collective plasma accelerators lie in producing beams of energetic electrons, protons, and gamma rays, as well as femtosecond pulses and compact radiation sources for medicine. Plasma-based charged particle acceleration schemes are also holding promises for extremely high-energy charged particles and radiation sources from astrophysical plasmas as well.However, in very dense plasmas, such as those in astrophysical environments [15][16][17][18] and in the next-generation intense laser-solid density plasma experiments [19][20][21][22][23], there might appear novel effects at the nanoscale owing to the presence of the new electron pressure law and the quantum force involving the Bohm potential [24][25][26][27][28]. This happens because in dense quantum plasmas the electrons degenerate and they follow the Fermi-Thomas distribution.In this letter, we consider the excitation of electrostatic ion wakefields by electromagnetic (EM) waves [29][30][31][32] in a very dense plasma. For this purpose, we use the quantum fluid model for the degenerate electrons and derive the ion wakefield equation in the presence of the ponderomotive force of the EM waves. The profile of the ion wakefield is deduced by assuming a given EM pulse shape. The relevance of our investigation is also mentioned.

Wakefield Excitation in Magnetized Quantum Plasma

“…It has been demonstrated that quantum effects can be important even in the classical regime [61,62]. The excitation of electrostatic wakefields in a quantum plasma by the ponderomotive force has been studied [63][64][65][66] and it has been found that the plasma number density plays an important role in the transition from wakefield generation to soliton formation [67].…”

Polarization effect of a chirped Gaussian laser pulse on the electron bunch acceleration

“…For most practical applications, high-quality particle beams with high spatial quality and monoenergetic energy distribution are required. In order to produce high-quality beams from laser-based accelerators, numerous investigations have treated the subject experimentally and theoretically [1][2][3][4][5]. Among the wellknown laser-driven acceleration schemes, much work has been carried out studying the vacuum laser acceleration by an ultra-intense short laser pulse [6][7][8][9][10][11].…”