Beam Velocity and Density Influences on Ion-Beam Pulses Moving in Magnetized Plasmas

The wakefield and stopping power of an ion-beam pulse moving in magnetized plasmas are investigated using particle-in-cell simulations. The effects of beam velocity and density on the wakefield and stopping power are discussed. Besides the longitudinal inverted V-shaped wakes, strong whistler waves are observed when low-density and low-velocity pulses move in plasmas in the presence of a magnetic field. The corresponding stopping powers are enhanced because of drag from these whistler waves. As the beam velocities increase, the whistler waves disappear, and only inverted V-shaped wakes are observed. The corresponding stopping powers are reduced compared with those in isotropic plasmas. When high-density pulses are transported in the magnetized plasmas, the whistler waves are greatly inhibited for low-velocity pulses and disappear for high-velocity pulses. In addition, the magnetic field reduces the stopping powers for all high-density cases.