Analysis Of Plasma Channel With Self-Generated Magnetic Field In Laser Plasma

Development of modern laser technology greatly pushed the work for lasernuclear fusion, it has been observed that hollow cylindrical plasma channel can beinduced near critical surface in laser-produced plasma, and the initial uniformhigh-frequency fields would exhibit the phenomenon of self-focusing and filamentin channel, at the same time, MG magnitude low-frequency magnetic field isexcited within channel. Stable plasma channel with adequate length is the key forrealizing quick ignition, and low-frequency magnetic field plays important role inpulse propagation and electronic acceleration. So plasma channel withlow-frequency magnetic field is an essential problem in laser nuclear fusion.In this paper, the results of observation are introduced in detail by theexperiment of plasma channel with low-frequency magnetic field near the criticalsurface in laser-produced plasma. The study of generated mechanism of channelwith low-frequency magnetic field is also commented. The concurrence of plasmachannel and self-generated magnetic field infers their absolute relation, our purposeis to find such relation. The theory for self-generated magnetic field derived byX.Q.Li describes the consistent relation of transverse wave, density perturbationand self-generated magnetic field: the incident laser collapses and breaks byinteraction of wave-wave and wave-particle, collapse fields expel particles byponderomotive force and density channel forms, at the same time, low-frequencynonlinear current induces low-frequency magnetic field. We do the numericalcalculation for the equations of self-generated magnetic field in two cases, i.e. staticlimit case and non-static limit case, and get the evolution of density channel andself-generated magnetic field, which agree with the recent observation results.