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EMMA -the Electron Model of Many Applicationsis to be built at the STFC Daresbury Laboratory in the UK and will be the first non-scaling FFAG ever constructed. EMMA will be used to demonstrate the principle of this type of accelerator and study its features in detail. The design of the machine and its hardware components are now far advanced and construction is due for completion in Autumn 2009.

This report describes the conceptual design of a proposed free electron laser test facility called CLARA that will be a major upgrade to the existing VELA accelerator test facility at Daresbury Laboratory in the UK. CLARA will be able to test a number of new free electron laser schemes that have been proposed but require a proof of principle experiment to confirm that they perform as predicted. The primary focus of CLARA will be on ultra short photon pulse generation which will take free electron lasers into a whole new regime, enabling a new area of photon science to emerge.

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The beam delivery system for the linear collider focuses beams to nanometer sizes at its interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the art beam instrumentation in order to reach the ILCs physics goals. This paper describes the design details and status of the baseline configuration considered for the reference design and also lists alternatives. SYSTEM DESCRIPTIONThe ILC Beam Delivery System (BDS) is responsible for transporting the e + /e − beams from the exit of the high energy linacs, focusing them to the sizes required to meet the ILC luminosity goals (σ * x = 639 nm, σ * y = 5.7 nm in the nominal parameters), bringing them into collision, and transporting the spent beams to the main beam dumps. In addition, the BDS must measure the linac beam and match it into the final focus (FF); protect the beamline and detector against mis-steered beams from the main linacs; remove any large amplitude particles (beam-halo) from the linac to minimize background in the detectors; measure and monitor the key physics parameters such as energy and polarization before and after the collisions. The BDS must provide sufficient instrumentation, diagnostics and feedback systems to achieve these goals.The main subsystems of the beam delivery starting from the exit of the main linacs are the diagnostics region, fast extraction and tuneup beamline, betatron and energy collimation, final focus, interaction region (IR) and extraction line. The layout of the beam delivery system is shown in Figs. 1 can be upgraded to 1 TeV with additional magnets. There is a single collision point with a 14 mrad crossing angle. The beam delivery systems are in line with the linacs and the linacs are also oriented at a 14 mrad angle. Two detectors in a common IR hall alternately occupy the single collision point, in a so-called "push-pull" configuration. The detectors are pre-assembled on the surface and then lowered into the IR hall in large subsections once the hall is ready for occupancy.The initial part of the BDS is responsible for measuring and correcting the properties of the beam before it enters the collimation and FF. In addition, errant beams must be detected here and safely extracted in order to protect the downstream systems. Starting at the exit of the main linac, the system includes the machine protection system (MPS) collimation, skew correction section, emittance diagnostic section, polarimeter with energy diagnostics, fast extraction/tuning system and beta matching section.At the exit of the main linac is a short 90• FODO lattice, composed of large bore quadrupoles, which contains a set of sacrificial collimators of decreasing aperture. This section also contains kickers and BPMs for inter-and intratrain trajectory feedback.

In certain high power RF systems multipactor cannot be avoided for all operating points, but its existence places limits on performance, efficiency, lifetime, and reliability. As an example multipactor in the input couplers of superconducting RF cavities can be a major limitation to the maximum RF power. Several studies have concentrated on rectangular waveguide input couplers which are used in many light sources. Most of these studies neglect space charge assuming that the effect of space charge is simply to defocus the electron bunches. Modelling multipactor to saturation is of interest in determining the performance of waveguide under a range of conditions. Particle-in-cell modelling including space charge has been performed for 500 MHz half-height rectangular waveguide. Phase plots of electron trajectories can aid understanding the processes taking place in the multipactor. Results strongly suggest that the multipacting trajectories are strongly perturbed by space charge causing the electrons to transition from two-surface to single-surface trajectories as the multipactor approaches saturation.