Collimated gamma photon emission driven by PW laser pulse in a plasma density channel

Abstract

We use three-dimensional particle-in-cell simulations to demonstrate that a plasma density channel can stably guide the petawatt laser pulse in near critical plasmas. In this regime, a directed, collimated, and micro-sized gamma photon beam is emitted by the direct-laser accelerated electrons along the channel axis. While in the case without the plasma density channel, the laser tilting behavior leads to the generation of randomly deflected gamma photon beams with a large divergence angle and transverse source size. In addition, in the plasma density channels, the divergence angle of the gamma photon beams can be much reduced by using a smaller value of n0/a0nc. The energy conversion efficiency can also be improved by increasing the laser power or the plasma density. This regime provides an efficient and compact approach for the production of high quality gamma photon beams.

Injection dynamics of direct-laser-accelerated electrons in a relativistically transparent plasma

“…In addition, it is pointed out that the self-generated azimuthal magnetic fields tend to suppress the injection process of electrons by deflecting them away from the laser field region. Understanding these physical processes paves the way for further optimizing the properties of direct-laser accelerated electron beams and the associated X/gamma-ray sources.High-energy electron beams are attractive for many applications ranging from fast ignition of inertial confinement fusion [1], radiography [2], and novel light sources [3][4][5], to neutron sources [6]. With the ability of supporting huge accelerating electric fields (above 100 GV/m), the laser-based plasma accelerators, which are promising to revolutionize the conventional accelerator technologies, recently have attracted much research attention.…”

“…High-energy electron beams are attractive for many applications ranging from fast ignition of inertial confinement fusion [1], radiography [2], and novel light sources [3][4][5], to neutron sources [6]. With the ability of supporting huge accelerating electric fields (above 100 GV/m), the laser-based plasma accelerators, which are promising to revolutionize the conventional accelerator technologies, recently have attracted much research attention.…”

“…It is shown from Eqs. (5) and (7) that the azimuthal magnetic field has a great influence on the electron injection dynamics. The azimuthal magnetic field B Sz is generated by the forward-moving electrons on the axis and increases from 0 to 2 × 10 5 T during the electron acceleration process.…”

Highly efficient laser-driven Compton gamma-ray source

“…Recently synchrotron photon emission in a relativistic transparency regime [27][28][29][30][31][32], where an ultra-intense laser pulse is incident onto a relativistically underdense target, was proposed as a relatively efficient scheme for the production of brilliant γ-rays. The strong coupling of an intense laser pulse with a relativistically underdense plasma can easily generate high-current high-energy electron beams and thus radiate high-flux γ-rays [33].…”

High density γ-ray emission and dense positron production via multi-laser driven circular target

“…Another way is to change the plasma target configuration, such as one or multiple laser interaction with near-critical-density plasma [28][29][30][31], solid Al target [32][33][34] or gas plasma [35,36]. Among them, laser wakefield acceleration [37] and laser ponderomotive acceleration [38,39] are generally used to enhance electron acceleration and constraint.…”