Hundreds-petawatt laser pulses shaping and heavy ion acceleration based on conical plasma channels

Abstract

<sec>In this work, the effects of conical plasma channels on the laser pulses shaping and the heavy ion acceleration under the extreme light field conditions of hundreds-petawatt are investigated by using a particle simulation method. The law of influence of the conical plasma channel on the spatio-temporal waveform and intensity of the incident laser is analyzed, when the quantum electrodynamics (QED) effect is taken into account. The reason for the shaping laser-enhanced heavy ion acceleration is given, and the role of the QED effect in the acceleration process is explained.</sec><sec>It is found that due to the non-linear interference and focusing effects, the conical plasma channel can shape the spatio-temporal waveform of the laser pulse and enhance the laser intensity. A tightly focused (beam waist radius < 1 μm) and ultra-high intensity (enhanced 6 times) shaping laser is obtained for a linearly polarized laser with an intensity of 5.46×10²² W/cm² and a waist radius of 10 μm at an incident angle of <i>θ</i> = 10°. In the simulation, the conical plasma channel is filled by fully ionized high-<i>Z</i> gold plasma with an electron density up to <i>n</i>_e = 2626.5<i>n</i>_c. Therefore most of the laser energy in the channel is reflected by the channel wall, and the QED effect has less influence on laser focusing and shaping. This laser is used to accelerate an ultra-thin flat target placed at the end of the channel. It is found that the radiation reaction force can effectively suppress the transverse expansion of the ultra-thin flat target, caused by the electron heating and the transverse non-uniform of the laser intensity. The transparency time of the ultra-thin flat target is prolonged, which will allow the gold ions to be fully accelerated. Ultimately, the gold ions can reach up to about 240 GeV in cutoff energy. These results are expected to provide theoretical reference and technical support for designing the future experiments on hundreds-petawatt laser heavy ion acceleration and their applications in high-quality ion source, such as nucleus-nucleus collisions.</sec>