Studies of moment aberrations in magneto-electrostatic plasma lenses

In this work it is shown that in magneto-electrostatic plasma lenses moment aberrations obey the law of conservation of generalized angular moment of the charged particle to be focused. They disappear when the particle source is placed in a zero magnetic field; geometrical aberrations can be removed by choice of the optimal electric field intensity distribution. In the case considered, the proton current density can achieve in the focus a value up to 10/sup 3/ A/cm/sup 2/.