An ion processing device includes electrically conductive vacuum manifold segments serially positioned and enclosing a volume along an axis. The segments are electrically isolated from each other and independently addressable by a voltage source. An ion optics device is positioned in the volume. A voltage differential between each manifold segment and the ion optics device is maintained below a maximum value by applying different voltages to respective manifold segments. The voltage differential may be controlled to avoid voltage breakdown in a low-pressure, high-voltage gas environment. The ion optics device may in some cases be an ion mobility drift cell.