| Since the concept was first suggested by M.Tabak in 1994,fast ignition is now an increasing research field for its merits that traditional inertial confine fusion(ICF) did not possess.But for its short time research,there are lots of physics need to be studied,among which the transportation of relativistic electrons in dense plasmas is an interesting and important subject.First of all,the basic contents of this thesis were outlined and recent researches on these topics were reviewed.Then the laser system and target chambers developed for experiments were introduced.In this part,the diagnostic equipments,such as CCD pinhole camera, electron spectrometer,single-photon counting CCD et al.In this paper,such five points are studied as:a) Hot electron spectrum in the interaction of relativistic laser with solid target was measured in the experiment,b) The single-photon counting CCD was carried out the energy calibration experiment using several standard X-ray sources,c) The study of Kαyield and the Kαconversion efficiency was carried out at the SILEX-1 laser facility in the China Academy of Engineering Physics(CAEP).d) Based on Monte Carlo ITS3.0 procedure and experiment,the laser-electron conversion is studied correspond to measuring the Kαyield of layered laser-irradiated disk targets,e)The total cross sections of electron impact single K-shell ionization of atomic targets Al,Ti,Cu and Mo,are evaluated in the energy range up to about 1Mev employing the relativistic correction method.Hot electron spectrum in the interaction of relativistic laser with solid target was measured in this experiment,and hot energy spectrum in front normal direction and rear laser propagation direction were obtained,in front normal direction,the sprctrum is a Maxwellian like distribution,which is produced by resonant absorption mechanism;Along the laser propagation,the spectrum is a Maxwellian like distribution,which is produced by the laser ponderomotive force.The single-photon counting CCD was used to detect Kαemission.We carried out the energy calibration experiment using several standard X-ray sources in National Institute of Metrology of China.The calibration shows photon with 6.453 eV can produce one count. Based on this result,the detection efficiency of the CCD is calculated.The detection efficiency changes with different photon energies in the range of 5.3 keV～30 keV.The efficiency decreased with the increase of photon energy. During the interaction of ultra-short and ultra-intense laser pulse with plasmas,high energy electrons will be produced near to critical-density surface.When the hot electrons knocked out inner-shell electrons of the cold material,Kαcharacteristic lines emission will be created.Kαemission is closely correlated with the hot electrons'action.From Kαlines emission,we can find some useful information of hot electron,such as its production and transport in overdense plasmas.On the other hand,such Kαemission has widely potential applications,especially for chatacteristic pulse light source,owing to its compactness and high fluence.For the motivation referred above,we carried out the experimental studies on the Kαcharacteristic lines emssion with the copper targets and multi-layers targets irradiated by US-UI laser.The Kαmeasurement was carried out at the UI-US laser facility in the China Academy of Engineering Physics(CAEP).Experement of Kαx-ray emission from ultra-short and ultra-intense laser pulse with copper planar target interaction:Using single-photon counting x-ray CCD,the yield of Kαx-ray was measured,which was emitted by interaction of 2×1018～1.96～1019W/cm2 P-polarized ultra-short and ultra-intense laser pulse with 10μm,30μm thick Cu planar film target,High intensity Kαx-ray was measured.The results show that the varying tendency of Kαx-ray yield and conversion efficiency as a function of laser intensity is accordant with the academic tendency.There is optimal intensity for both Kαx-ray yield and conversion efficiency.For 10μm Cu film target,Kαx-ray Yield is near-saturation at the intensity of 1.51×1019W/cm2 and the optimal intensity for the KαX-ray yield(2.1×1010) is 1.96×1019W/cm2,the conversion efficiency has a maximal value 1.2×10-5 as the intensity is 6.5×1018W/cm2.For 30μm Cu film target,the largest KαX-ray Yield is 2.2×1010 and the optimal intensity 8.9×1018W/cm2,the conversion efficiency has a maximal value 1.98×10-5as the intensity is 3.2×1018W /cm2.When the laser intensity is 3.3×1018W/cm2,as the same thick,the conversion efficiency of nanoparticle Cu is 3.3times larger than that of the ordinary copper planar target.In the experiment of the Kαfluorescence measurement with the multi-layers targets, keeping the laser intensity variable from 1017W/cm2 to 1019W/cm2.The targets are rectangular foils of various materials.The tracer layer(Al or Cu) has different thickness from 0.1μm to 7μm,and the fluorescent layer has the invariable thickness 50μm.Finally,a layer of 2μm thick CH covered the back of the target.It is demonstrated that Kαyield is related to many factors.With the laser intensity increase,Kαx-ray yield increase appoximately linear.The Kαyield is sensitive to the laser intensity.When the intensity increase from nonrelativistic to relativistic,the yield rise in magnitude.By varying the material or the depth of the tracer layer,the Kαyield changed accordingly,the higher atom number Z,the higher Kαyield obtained;the thicker layer,the fewer Kαyield obtained.Based on Monte Carlo(ITS3.0) procedure,studied the photon share which the hot electron produces,according to the experiment result,to the different material and the different thickness of tracer layer,the hot electron conversion efficiency of the interaction of ultrashort laser -irradiated compound target has carried on the computation,The result discovered that, the efficiency seems to be a function of intensity but not target material.At non-relativistic intensity,as the intensity increases,the laser-electron conversion efficiency increases with the max efficiency 10%because of resonance absorption.Within the relativistic intensity,the conversion efficiency is in the range of(14～20)%with ponderomotive acceleration dominatingly.
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