Future Upgrades for the PHENIX Experiment at RHIC: From PHENIX to sPHENIX and Beyond

A series of major upgrades are being planned for the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) to enable a comprehensive measurement of jets and quarkonia in relativistic heavy ion collisions in order to study the phase transition of normal nuclear matter to the Quark Gluon Plasma near its critical temperature. These upgrades will include a number of major new detector systems. The former BaBar solenoid magnet will be incorporated in the first stage, sPHENIX. Further upgrades will include two new large calorimeters. In the following these upgrades and their requirements are being presented.