170 / 2023-04-15 08:33:48

Short pulse neutron sources driven by relativistic femtosecond lasers

Laser-driven neutron source, Pitcher-catcher targets, femtosecond laser pulses

极端光下的基础物理学 > 极端光下的基础物理学-海报

Relativistic laser-driven neutron source has the advantages of small focal spot, short pulse width and high peak flux, which is very useful in the fields of non-destructive and isotope-sensitive material analysis, and nuclear science and application. For the typical laser parameters of current hundreds-petawatt and multiple-petawatt laser facilities, we investigate the nonlinear dynamics of relativistic femtosecond lasers interacting with solid targets, and then propose several schemes to improve the quality of laser-driven neutron sources. By using multiple lasers and microstructure plasmas, the efficiencies of particle acceleration and neutron production rates are dramatically improved. Short pulsed photonuclear and beam-target neutron sources with the yield per Joule above 10⁸ n/J are predicted. Besides, we also propose a method to control the directionality of neutron source by changing the rotation direction of electric field vector and initial relative phase difference of two counter-propagating circularly polarized laser pulses. A femtosecond-class directional pulsed neutron source can be obtained. These results may provide some reference for the experimental generations of laser-driven neutron sources and their applications.