Ectoplasmic Energy Capacitor
The ectoplasmic energy capacitor was a device constructed by Peter Venkman as a ghost attractor. Peter believed he was successful, but the ghosts arriving at Ghostbusters Central were actually trying to hide within the Containment Unit to escape from Mee-Krah. When Mee-Krah arrived at Manhattan, Egon realized Peter had really invented an ectoplasmic energy capacitor, capable of absorbing minute amounts of ectoplasmic energy from nearby ghosts. The strongly charged capacitor was turned on Mee-Krah, destroying the gigantic entity, but unfortunately the Capacitor melted in the process- and Peter never kept any notes during its construction.