Comparative study of ultrashort single-pulse and multi-pulse driven laser wakefield acceleration

Abstract

Laser wakefield acceleration (LWFA) is a promising technique to build compact and powerful particle accelerators. In such accelerators, the electric fields required to accelerate charged particles are sustained by electron density modulations in the plasma. The plasma wave modulating the electron density may be excited by an intense laser pulse. However, propagation of intense laser pulse in plasma is subject to various instabilities which result in significant losses of laser energy, reducing the efficiency of wakefield generation. Using a train of lower intensity pulses instead of a single higher intensity pulse appears to be a more efficient scheme for LWFA. Here we have studied this alternative scheme by applying an ultra-short femtosecond Gaussian laser beam consisting pulse train of a various number of pulses in different cases to underdense plasma. The plasma density modulation and strength of the resulting wakefield have been compared in various cases of multi-pulse and single-pulse lasers, for the same amount of input energies. Here we demonstrate that applying multi-laser pulses of optimally selected lower intensities and proper spacing leads to stronger wakefield generation and more efficient electron acceleration compared to the case of a single pulse of higher energy.

Self-focusing and defocusing phenomena of super-Gaussian laser beams in plasmas carrying density gradient

“…The super-Gaussian beams have been found to be a better candidate for the third harmonic generation [50]. Not only this, studies have shown significant impact of the laser intensity profile and laser parameters on the amplitude of the wakefield [51] generated during the propagation of laser pulses and trapping of high-quality electron bunch in the bubble [52]. These laser beams, when skewed or launched as such, have also been found to be superior in other areas of optics also [53][54][55].…”

Effect of trapezoidal plasma density region in bubble wakefield acceleration

“…These electrons are then trapped in the first wake at the tail of the bubble and can be self-injected into the bubble [11][12][13][14][15][16][17][18][19][20]. Selfinjection of plasma electrons in bubble wakefield is the development for generation of high quality electrons beam [21][22][23][24][25][26][27][28][29][30]. These high quality electron beams are being used for many applications such as material characterization [31], generation of synchrotron radiations such as betatron radiations, and these radiations have been used in medical treatments [32][33][34][35][36][37] and many more [38][39][40][41][42].…”