An Electrostatic Quadrupole

A pure electrostatic quadrupole is defined by the command: 5 E(LECTROSTATIC) Q(UADRUPOLE) <effective length $\ell$ of quadrupole in meter> <V_Q in kV at electrode> <aperture radius G₀ in meter> ; [example: E   Q   0.1   1.0   0.03 ;]