CDX-U

The Current Drive Experiment-Upgrade (CDX-U) was an upgraded version of CDX located at PPPL. CDX-U was the first spherical tokamak in the United States and was originally made to continue the research from CDX but in a spherical tokamak configuration. In 2000, CDX-U began operations with a liquid lithium limiter in contact with the plasma. This addition made a major improvement in the energy confinement time since the lithium absorbs impurities which drive energy losses. These results led to the transformation of the device into LTX in 2005.