Related papers: Manifold Damping Of Wakefields In High Phase Advan…

Operating the SLAC/KEK DDS (Damped Detuned Structure) X-band linacs at high gradients (in excess of 70MV/m) has recently been found to be limited by the accelerator structures breaking down and as a consequence severe damage occurs to the…

Recent experiments at SLAC [1,2] and CERN [3] have revealed evidence of significant deformation in the form of "pitting" of the cells of the 1.8m series of structures DDS/RDDS (Damped Detuned Structure/Rounded Damped Detuned Structure).…

In the NLC (Next Linear Collider) small misalignments in each of the individual accelerator structures (or the accelerator cells) will give rise to wakefields which kick the beam from its electrical axis. This wakefield can cause BBU (Beam…

In damping the wakefield generated by an electron beam traversing several thousand X-band linacs in the NLC we utilise a Gaussian frequency distribution of dipole modes to force the modes to deconstructively interfere, supplemented with…

In the NLC project multiple bunches of electrons and positrons will be accelerated initially to a centre of mass of 500 GeV and later to 1 TeV or more. In the process of accelerating 192 bunches within a pulse train, wakefields are excited…

We report on suppression of long-range wakefields in CLIC accelerating structures. Strong detuning and moderate damping is employed. In these initial design studies we focus on the CLIC_G structure and enforce a moderate Q of 300 and 500.…

A Damped Detuned Structure (DDS) for CLIC main linac has been proposed as an alternative to the present baseline design which is based on heavy damping. A first prototype, CLIC_DDS_A, for high power tests has been already designed and is…

The main linacs of the Next Linear Collider (NLC) will contain several thousand X-band RDDS (Rounded Damped Detuned Structures). The transverse wakefield in the structures is reduced by detuning the modal frequencies such that they…

The present design of the main accelerating structure for CLIC is based on heavy damping (WDS) with a Q of ~10. The wakefield suppression in this case entails locating the damping materials in relatively close proximity to the accelerating…

The progress of a multiple bunches of electrons through several thousand accelerator structures results in a wakefield which if left unchecked will kick successive bunches off the axis of the accelerator and can at the very least dilute the…

In the JLC/NLC X-band linear collider, it is essential to reduce the long-range dipole wakefields in the accelerator structure to prevent beam break up (BBU) and emittance degradation. The two methods of reducing the long-range wakefields…

The complexity of the Round Damped Detuned Structue (RDDS) for the JLC/NLC main linac is driven by the considerations of rf efficiency and dipole wakefield suppression. As a time and cost saving measure for the JLC/NLC, the dimensions of…

In fabricating the first X-Band RDDS (Rounded Damped Detuned Structure) accelerator structure, microwave measurements are made on short groups of discs prior to bonding the discs of the entire structure. The design dispersion curves are…

A damped detuned structure for the main X-band linacs of CLIC is being investigated as an alternative design to the present baseline heavily damped structure. In our earlier designs we studied detuned structures, operating at 11.994 GHz,…

The key feature of the improved coupling design in the Damped Detuned Structure (DDS) is focused on the four manifolds. Rectangular geometry slots and rectangular manifolds are used. This results in a significantly stronger coupling to the…

The main accelerating structures for the CLIC are designed to operate at an average accelerating gradient of 100 MV/m. The accelerating frequency has been optimised to 11.994 GHz with a phase advance of 2{\pi}/3 of the main accelerating…

A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab…

The number of cells in a $\pi$-mode standing wave (SW) accelerating structure for the Compact linear Collider (CLIC) project is limited by mode overlap with nearby modes. The distributed coupling scheme avoids mode overlap by treating each…

During the course of the last decade, traveling wave accelerating structures for a future Linear Collider have been the object of intense R&D efforts. An important problem is the efficient computation of the long range wakefield with the…

We show that scattering matrix calculations for dipole modes between 23-43 GHz for the 206 cell detuned structure (DS) are consistent with finite element calculations and results of the uncoupled model. In particular, the rms sum wake for…