X-ray Source Characteristics And Application Research Under High Power Laser Loading

X-ray probe is a very important diagnostic technology in the HEDP experiment.It was used for observeing evoluton of complex systems in extreme conditions for verifying HEDP theory and numerical simulation model.Character of X-ray sources is important to diagnostic system in HEDP experiments.It's the important basis about feasibility evaluation of diagnostic proposal.X-ray sources produced by high power laser are the most fit of requirements under HEDP laboratory environment(picosecond time-resolved,dozens of micron spatial resolution).In this paper,we satisfy the requirements of HEDP experiments to develop 1-60 keV band X-ray probe.We study characteristic of X-ray sources driven by nanosecond laser or ultra-short pulse laser.The main content of my research work is divided into two parts:First part,we studied characteristics and optimation of 1-5keV X-ray backlighting sources driven by nanosecond laser for meeting requierment of ICF experiments in shenguang-? and shenguang upgrade facility.Content as follows:(1)A variety of optimization schemes about titanium backlighter driven by nanosecond laser sources were studied.We made a scrutiny into characters of X-ray radiation above 4keV,such as spatial distribution,X-ray pulse shape,spectrum distribution and relative intensity of line spectrum.Optimization schemes of titanium backlighter sources in shenguang-? facility were analyzed by XRL-2D radiation fluid dynamics code.(2)To develop high temporal and spatial resolution of X-ray imaging diagnostic techniques,we studied titanium,chlorine,molybdenum X-ray backlighting(k-shell or L-shell line-spectrum)driven by nanosecond laser.And we design highly effective,monochromatic area backlighting probe for KB imaging system in shenguang-? laser facility.(3)We carried out a series of experiments about Cu backlighter souces driven by nanosecond laser pulse in shenguang-? laser facility.For the first time,we used pure copper aerogel to optimize copper backlighter.We obtained characteristic parameters,such as Cu K-shell and L-shell spectrum,X-ray pulse duration.Combined with mumerical simulation,we analyed the optimization experiment about pure copper aerogel target in shenguang-? laser device.Sencond part,In order to satisfy the needs of ICF experiments in shenguang-?upgrade and shenguang-? laser facility.We decided to develop the stable output technology of Ka sources driven by ultrashort pulse laser,to expand the X-ray diagnostic ability.Concrete content as follows:(1)We carried out experiment about Ka radiation driven by picosecond laser pulse in shenguang-? upgrade device.We studied copper K-shell line spectrum in different laser intensity and different thickness of target;Ka photon conversion efficiency was measured by single photon CCD in different driving conditions.And we also analysised the electron spectrum in laser propagation directon and target normal direction by electron spectrometer.We carried out backlighting application experiment by flag target.(2).We carried out numerical simulation work about Ka radiaiton by using PIC particle code and Monte Carlo code.We set up the physical model about hot electron bound by the sheath field,analyzed relation between the K? conversion efficiency and laser intensity in the conditions of different initial density.The main electron acceleration mechanism was studied by analysis the picture of elctron momentum distribution.