constEMField:
Kind of EmField that defines a constant field.
elecField (float vector)The electric field.
magField (float vector)The magnetic field.
hasB (option, default=true)Flag to specify that the magnetic field (if present) will be used in the species update step.
<EmField constEM>
    kind = constEmField
    elecField = [0. 0. 0.]
    magField = [0. 0. 0.]
</EmField>