Philip Burrows

Abstract:

The CLIC drive beam provides RF power for acceleration of the main beam, and hence thedrive beam's longitudinal phase tolerances are very tight. A feedforward chicane consistingof four electromagnetic kickers is proposed as a correction system for the phase errors,which should allow loosening of the tolerances. A prototype of such a chicane systemdeveloped by CERN, INFN and the University of Oxford, is planned to be installed at CTF3 in2012. The present paper summarizes the parameters of the planned phase correction systemand presents simulations, which are used to make predictions of the performance of such afeedforward system at CTF3. Copyright © 2012 by IEEE.

Abstract:

For future linear colliders the precise control and mitigation of pulse-to-pulse orbit jitter will be very important to achieve the required luminosity. Diagnostic techniques for the orbit jitter measurement and correction for multibunch operation are being addressed at the KEK Accelerator Test Facility 2 (ATF2). In this paper we present recent studies on the vertical jitter propagation through the ATF2 extraction line and final focus system. For these studies the vertical pulse-to-pulse position and angle jitter have been measured using the available stripline beam position monitors in the beamline. The cases with and without intra-train orbit feedback correction in the ATF2 extraction line are compared. Copyright © 2012 by IEEE.

Abstract:

Future lepton colliders such as the International Linear Collider (ILC), and the Compact Linear Collider (CLIC) require nanometer-sized beams at the interaction point (IP). We report on the design, protoyping and testing of beam-based feedback systems for steering the beams into collision at the IP so as to maximise the luminosity performance of the colliders. Both all-analogue and digital feedback prototypes have been built and tested for CLIC and ILC, respectively. The latency of such systems needs to be very low so as to match the bunch spacing and bunch-train length. We report on the achievement of systems with 130ns and 23ns latency that meet the beam position resolution and beam kick requirements of both ILC and CLIC, respectively; the prototypes were tested with ILC- and CLIC-like beams at the Accelerator Test Facility at KEK. We have simulated the measured performance and demonstrated the potential of the feedbacks to compensate for ground-motion disruption and recover almost all of the design luminosity.