A retractable lead system is provided that includes a cup, a spherical contact, and a plunger. The cup is disposed proximate a vacuum end of the retractable lead system, and defines a cavity and a contact reception seat. The contact reception seat defines a spherical portion having a contact reception spherical radius. The spherical contact is disposed within the contact reception seat, and defines a contact spherical radius that corresponds to the contact reception spherical radius. The spherical contact is configured to be electrically coupled to an interior lead disposed within a vacuum environment. The plunger includes an ambient contact and a retractable contact disposed on opposite ends of the plunger. The plunger is configured to be actuated between an open position at which the retractable contact is retracted from the spherical contact and a closed position at which the retractable contact is coupled with the spherical contact.
