The simple surface current model is extended to study the generation of high-order harmonics for a relativistic circularly polarized laser pulse interacting with a plasma grating surface. Both exact relativistic elect...The simple surface current model is extended to study the generation of high-order harmonics for a relativistic circularly polarized laser pulse interacting with a plasma grating surface. Both exact relativistic electron dynamics and optical interference of surface periodic structure are considered. It is found that high order harmonics in the specular direction are obviously suppressed whereas the harmonics of the grating periodicity are strongly enhanced and folded into small solid angles with respect to the surface direction. The conversion efficiency of certain harmonics is five orders of magnitude higher than that of the planar target cases. It provides an effective approach to generate a coherent radiation within the so-called ＇water window＇ while maintaining high conversion efficiency and narrow angle spread.展开更多
Heating of over-dense plasma represents a long-standing quest in laser-plasma physics.When the strength of the magnetic field is above the critical value,a right-handed circularly polarized laser could propagate into ...Heating of over-dense plasma represents a long-standing quest in laser-plasma physics.When the strength of the magnetic field is above the critical value,a right-handed circularly polarized laser could propagate into and heat up the highly magnetized over-dense collisional plasma directly;the processes are dependent on the parameters of the laser,plasma and magnetic field.The parametric dependence is fully studied both qualitatively and quantitatively,resulting in scaling laws of the plasma temperature,heating depth and energy conversion efficiency.Such heating is also studied with the most powerful CO_(2) and strongest magnetic field in the world,where plasma with density of 10^(23)cm^(-3) and initial temperature of 1 keV is heated to around 10 keV within a depth of several micrometres.Several novel phenomena are also discovered and discussed,that is,local heating in the region of high density,low temperature or weak magnetic field.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11375265,11475259 and 11675264the National Basic Research Program of China under Grant No 2013CBA01504the Science Challenge Project under Grant No JCKY2016212A505
文摘The simple surface current model is extended to study the generation of high-order harmonics for a relativistic circularly polarized laser pulse interacting with a plasma grating surface. Both exact relativistic electron dynamics and optical interference of surface periodic structure are considered. It is found that high order harmonics in the specular direction are obviously suppressed whereas the harmonics of the grating periodicity are strongly enhanced and folded into small solid angles with respect to the surface direction. The conversion efficiency of certain harmonics is five orders of magnitude higher than that of the planar target cases. It provides an effective approach to generate a coherent radiation within the so-called ＇water window＇ while maintaining high conversion efficiency and narrow angle spread.
基金the Start-up fund from Shantou University(No.NTF21003)the Science and Technology Fund of Guangdong Province(No.STKJ2021018)the National Natural Science Foundation of China(NSFC)(No.12075317).
文摘Heating of over-dense plasma represents a long-standing quest in laser-plasma physics.When the strength of the magnetic field is above the critical value,a right-handed circularly polarized laser could propagate into and heat up the highly magnetized over-dense collisional plasma directly;the processes are dependent on the parameters of the laser,plasma and magnetic field.The parametric dependence is fully studied both qualitatively and quantitatively,resulting in scaling laws of the plasma temperature,heating depth and energy conversion efficiency.Such heating is also studied with the most powerful CO_(2) and strongest magnetic field in the world,where plasma with density of 10^(23)cm^(-3) and initial temperature of 1 keV is heated to around 10 keV within a depth of several micrometres.Several novel phenomena are also discovered and discussed,that is,local heating in the region of high density,low temperature or weak magnetic field.
