Development Of Major Systems Of A Helicon Plasma Device And Experiments On Turbulent Transport Characteristics In Its Helicon Plasma

Edge plasma turbulent transport and plamsa material interaction(PMI)are two major challenges in the field of magnetic confined fusion.These two topics are correlated with each other and jointly affect the boundary plasma characteristics,which is closely related to core plasma parameters.Delicated researches on these two topics are necessrary.It is very expensive to build,operate and maitaina a large tokamak,which can provide limited time for experiments.Linear Plasma Devices(LPD)have the advantages of cheap cost,short construction duration and ease of operation,which can achieve the stable discharge and allow precise diagnoistics for the entire plasma.Therefore,as an important complement to the tokamaks,the LDPs effectively support the experiment researches on turbulent transport and PMI.In this thesis,key systems including the heicon plasma source,magnets are developed for the linear plasma deviec named Linear Experimental Advanced Device(LEAD)built in Southwestern Institute of Physics(SWIP).To satisfy the requirements of turbulence and PMI experiments,the vacuum chamber consists of 3 sections for the plasma source,diagnoistics and target.The diameter of the target section is enlarged and has the tilted windows for the high-energy ion beam,laser beam and diagnostics for the PMI experiment.To generate a uniform axial magnetic field under the constraints of the special geometry of the vacuum chamber,the space reserved for the ion beam,the capacity of the cooling and power supply and the fabricating cost,the size,location,number of turns and currents of the magnets system are optimized by computer simlulation.After the optimization,the axially-unifrom 0.2 T magnetic field with ripple less than 2.5%can be generated within the above mentioned constrains.A largediameter multi-ring planar helicon plasma source is developed to satisfy the demands of high-density,large-diameter plasma column for PMI and turbulence experiments.The diameter of the antenna is up to 32 cm.All parts of the helicon plasma source are in the atomosphere,thus the system is highly-reliable and easy to maintain.The high-density large-diameter plasam columns can be generated efficiently in a vast range of external parameters,including the magnetic field,neutral pressure and radio-frequency(RF)power.In LEAD,the high density helicon plasma with electron density over 1018 m-3 can be achieved with RF power as low as 150 W,while most other similiar linear devices need about 1 kW to achieve similiar plasma parameter.With 3 kW RF power,the plasma density can be increased to above 1019 m-3,and the average particles produced by 1 Watt of power is much more than most helicon plasma source.During the turbulence experiments,it is found that there is significant radiallyinward particle flux induced by turbulence in the helicon plasma.Meanwhile,the drastic shearing E × B flow is formed by the turbulence-induced momentum transport,which could suppress the particle transport.Turbulent transport of the momentum and particles shaped the peaking radial profile of the mean electron density of the helicon plasma in LEAD.