Scaling laws for e(+)/e(-) linear colliders

Design studies of a future TeV e(+)e(-) Linear Collider (TLC) are presently being made by five major laboratories within the framework of a world-wide collaboration. A figure of merit is defined which enables an objective com parison of these different designs. This figure of merit is shown to depend only on a small number of parameters. General scaling laws for the main be am parameters and linac parameters are derived and prove to be very effecti ve when used as guidelines to optimize the linear collider design. By adopt ing appropriate parameters for beam stability, the figure of merit becomes nearly independent of accelerating gradient and RF frequency of the acceler ating structures. In spite of the strong dependence of the wake fields with frequency, the single-bunch emittance blow-up during acceleration along th e linac is also shown to be independent of the RF frequency when using equi valent trajectory correction schemes. In this situation, beam acceleration using high-frequency structures becomes very advantageous because it enable s high accelerating fields to be obtained, which reduces the overall length and consequently the total cost of the linac. (C) 1999 Elsevier Science B. V. All rights reserved.