Next Linear Collider Design Status

The layout of the Next Linear Collider (NLC) has been revised to provide greater physics capabilities and to make the design more cost effective. The basic rf unit for the main linacs uses a solid-state modulator to drive eight 70 MW klystrons with a 3 ms pulse length. The rf power is distributed with a multi-mode Delay Line Distribution System (DLDS) to 8 girders of accelerating structures. This configuration improves the AC to rf efficiency while reducing the number of modulators and klystrons required by a factor of two. Using a new compact design for the final focus, the NLC now has two different Interaction Regions (IR), one for high energy (250 GeV-1 TeV cms) and one for low energy (90-500 GeV cms). The high energy IR has minimum bending to support an eventual upgrade to 3-5 TeV cms. The low energy IR is optimized for precision studies at the Z-pole, W-pair, Top and possibly Higgs threshold. The design allows for beam to be shared between the two IRs and the possibility of 180 hz operation is under study. The present design provides flexibility for a variety of upgrade and staging scenarios from initial operation at low energy to amore » future extension to multi-TeV.« less