Study Of The Bootstrap Current In The EAST Tokamak

Bootstrap current is a very economic way for the operations of tokamak that it isproduced by plasma itself,it can improve the plasma confinement in the tokamak. With other noninductive current driven and bootstrap current,plasma current can reach the 100% noninductive current fraction without ohmic current.Large fraction of bootstrap current is necessary for the steady state nuclear fusion.Relationship between plasma parameters and bootstrap current is studied first in the paper,It is found that center temperature and center density have a great influence on the bootstrap current fraction.The profiles of temperature and the density also influence the profiles of bootstrap current.The temperature distribution parameters change the distribution of bootstrap current fraction more obviously than the density profile. Geometric parameter, longitudinal field, effective charge also have influence in different level. The influence of lower hybrid current driven on the bootstrap current are also studied in the paper when the total current is constant. With the off-axis lower hybrid current increasing, the bootstrap current fraction can be effectively changed. The results are useful and can give good reference for tokamak fusion experiment.