Overview of the X-band R and D Program

An electron/positron linear collider with a center-of-mass energy between 0.5 and 1 TeV is recognized as an important complement to the physics program of the LHC. The Next Linear Collider (NLC) is being designed by a US collaboration (FNAL, LBNL, LLNL, and SLAC) which is working closely with the Japanese collaboration that is designing the Japanese Linear Collider (JLC). The NLC/JLC main linacs are based on normal conducting 11 GHz rf. This paper will discuss the status of the NLC design. Results from the ongoing R and D programs, including the recently uncovered high gradient damage problem, will be discussed along with changes to the optical design and collider layout which were made to enhance the collider capabilities