SUMMARY OF THE RF TECHNOLOGY WORKING GROUP (T3)

The next-generation linear collider will require high-power microwave sources and accelerating systems vastly more challenging than its predecessor, the Stanford Linear Collider (SLC). Cost efficiency will demand high accelerating gradient to achieve beam energies five to ten times greater than in the SLC. Luminosity goals 10,000 times greater than the SLC demand efficient creation of the highest possible beam power without degradation of beam emittance. The past decade of R and D has demonstrated the feasibility of two technical approaches for building a 500-GeV center-of-mass system (cms) collider with attractive options for future upgrade. The TESLA R and D program offers the prospect of 1.3-GHz superconducting rf (srf) linacs with 23.4 MV/m gradient that can be upgraded later to 35 MV/m gradient by doubling the number of klystrons and the cryo-plant, to reach 800 GeV cms [1]. The Next Linear Collider (NLC) and Japanese Linear Collider (JLC) R and D programs offer the prospect of 11.4-GHz room-temperature linacs that can later be extended to 1 TeV by doubling the number of structures and klystrons, and to 1.5 TeV by additionally increasing gradient or length [2-4]. Both programs offer a 500-GeV linear collider project start within the next few years (2-3 years for TESLA, 3-4 years for NLC) based on available technology validated by experiments at several complementary test facilities. Both offer their upgrades as a result of further progress in R and D that is already underway