Laser irradiation of solid targets can drive short and high-charge relativistic electron bunches over micron-scale acceleration gradients.However,for a long time,this technique was not considered a viable means of ele...Laser irradiation of solid targets can drive short and high-charge relativistic electron bunches over micron-scale acceleration gradients.However,for a long time,this technique was not considered a viable means of electron acceleration due to the large intrinsic divergence(∼50°half-angle)of the electrons.Recently,a reduction in this divergence to 10°–20°half-angle has been obtained,using plasma-based magnetic fields or very high contrast laser pulses to extract the electrons into the vacuum.Here we show that we can further improve the electron beam collimation,down to∼1.5°half-angle,of a high-charge(6 nC)beam,and in a highly reproducible manner,while using standard stand-alone 100 TW-class laser pulses.This is obtained by embedding the laser-target interaction in an external,large-scale(cm),homogeneous,extremely stable,and high-strength(20 T)magnetic field that is independent of the laser.With upcoming multi-PW,high repetition-rate lasers,this technique opens the door to achieving even higher charges(>100 nC).展开更多
基金supported by Grant Nos.11-IDEX-0004-02 and ANR-17-CE30-0026-Pinnacle from Agence Nationale de la Recherchethe European Union’s Horizon 2020 research and innovation program under Grant Agreement No.654148 Laserlab-Europe+3 种基金the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(Grant Agreement No.787539)This work was supported by the Ministry of Education and Science of the Russian Federation under Contract No.14.Z50.31.0007The work of JIHT RAS team was done under financial support of the Russian Science Foundation(Grant No.17-72-20272)The research leading to these results is supported by Extreme Light Infrastructure Nuclear Physics(ELI-NP)Phase I,a project co-financed by the Romanian Government and European Union through the European Regional Development Fund.
文摘Laser irradiation of solid targets can drive short and high-charge relativistic electron bunches over micron-scale acceleration gradients.However,for a long time,this technique was not considered a viable means of electron acceleration due to the large intrinsic divergence(∼50°half-angle)of the electrons.Recently,a reduction in this divergence to 10°–20°half-angle has been obtained,using plasma-based magnetic fields or very high contrast laser pulses to extract the electrons into the vacuum.Here we show that we can further improve the electron beam collimation,down to∼1.5°half-angle,of a high-charge(6 nC)beam,and in a highly reproducible manner,while using standard stand-alone 100 TW-class laser pulses.This is obtained by embedding the laser-target interaction in an external,large-scale(cm),homogeneous,extremely stable,and high-strength(20 T)magnetic field that is independent of the laser.With upcoming multi-PW,high repetition-rate lasers,this technique opens the door to achieving even higher charges(>100 nC).
