Global instability structure in a linear beam confinement system

We investigate instabilities of electron beam particles confined in a cylindrical chamber using a 3-dimensional full particle simulation. The global structure of electron beam plasma changes within 1 μs, and deforms to those formed by the instabilities such and the sausage and kink instabilities. The azimuthal mode of the electron density on the midplane of beam plasma is analyzed and the amplitude of mode number of 1 or more increases at 0.2 μs. It was also found that the temporal change of the electron density on the geometric axis is caused by the plasma oscillation. (author)