Princeton Plasma Physics Laboratory (PPPL) is a national laboratory that conducts research into plasma physics and fusion energy science. It is operated by Princeton University under contract with the U.S. Department of Energy's Office of Science. PPPL houses the National Spherical Torus Experiment-Upgrade (NSTX-U), a major fusion research device that studies magnetically confined high-temperature plasmas. Researchers at PPPL develop technologies and theoretical models to advance magnetic confinement fusion as a potential energy source. The laboratory collaborates with other national labs, universities, and international partners on fusion experiments and plasma applications. PPPL also works on plasma technologies for spacecraft propulsion and laboratory astrophysics. Its primary sponsor is the DOE, with additional funding from other government agencies. The lab employs over 600 staff and hosts visiting scientists from around the world.