MULTI-BAND DIPOLE AND MULTIPOLE WAKEFIELDS IN NLC TRAVELING WAVE ACCELERATORS USING A WIRE MEASUREMENT TECHNIQUE

Dipole wakefields in NLC (Next Linear Collider) structures have been measured with ASSET [1] and well predicted by a circuit model [2]. However, the experimental technique is both time-consuming and expensive. Here, we report on kick factor and synchronous frequency determination for 1st and higher order dipole bands for TW (Traveling Wave) accelerators via a wire measurement technique. This stand-alone technique is relatively inexpensive and may lead to an efficient determination of wakefield parameters. The perturbative effect of the wire on the dipole band is pointed out and a two-wire scheme with a limited perturbative effect is also discussed. [1] C. Adolphsen, 1997, SLAC-PUB-7519 [2] R.M. Jones et al, LINAC96, SLAC-PUB-7287