LAUSR

The helicon wave heating and current drive in the HL-2M tokamak for the steady-state scenario is studied numerically. Based on the theory of fast wave current drive proposed by Chiu, we analyze the characteristics of helicon waves damping for the HL-2M tokamak. For wave frequencies larger than 420 MHz, strong wave damping occurs, and electron Landau damping is dominant. Moreover, a strong wave absorption region associated with the dimensionless parameters $$\beta _{e}$$ and $$\xi _{e}$$ that depend on the wave frequency is obtained. The helicon wave propagation and current drive are simulated using the GENRAY/CQL3D code. The results show that an off-axis current drive with profiles peak at $$\rho \sim 0.4$$ can be generally received at a wave frequency $$f\sim 500$$ MHz and the launched parallel refractive index $$n_{//}=3.8$$ and that the current drive efficiency reaches up to $$\sim$$ 140 kA/MW. A scan of $$n_{//}$$ showed that both the current drive profile peak and the generated current could be adjusted by changing the launched $$n_{//}$$ . Finally, a feasible scheme for the helicon wave off-axis current drive in the HL-2M tokamak is proposed.