Van de Graaff Generator Simulator (2D)

This 2D simulator models a real Van de Graaff generator: a rubber belt picks up triboelectric charge at its base roller, carries it up to a grounded comb that transfers it onto the hollow metal dome, and the dome's voltage climbs toward a corona-limited saturation point set by its radius. Bring the adjustable grounded sphere close enough and the air gap breaks down before that saturation point is reached, firing a visible spark that discharges the dome — all driven by a real charge-conservation and electrostatic-breakdown model, with a live charge, voltage and field readout.