Experimental study on the axial compression of a pure electron plasma simulating space-charge-dominated beam

An axial temperature and radial density distribution of a pure electron plasma have been measured before and after the compression in the longitudinal direction under a strong and weak magnetic fields. The time evolution of the temperature can be interpreted as that of beam emittance during the longitudinal pulse compression of charged-particle beam. Tune depression can be controlled by a density of the electrons and a magnetic field strength of the trap. The increase ratio of the axial temperature during the compression under the weak magnetic field is almost 1.7 times larger than that under the strong magnetic field. On the other hand, the radial density distribution remains unchanged as the initial condition in both cases. (author)