Molloy, S.

Paper	Title	Page
MOPP039	Beam-Based Alignment, Tuning and Beam Dynamics Studies for the ATF2 Extraction Line and Final Focus System	634
	G. R. White, S. Molloy, M. Woodley SLAC, Menlo Park, California
	Using a new extraction line currently under construction, the ATF2 experiment plans to test the novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. With a 1.3 GeV design beam of 30nm normalised vertical emittance extracted from the ATF damping ring, the primary goal is to achieve a vertical spot-size at the IP waist of 37nm. We discuss our planned strategy for tuning the ATF2 beam to meet the primary goal. Simulation studies have been performed to asses the effectiveness of the strategy, including “static” (installation) errors and dynamical effects (ground-motion, mechanical vibration, ring extraction jitter etc.). We have simulated all steps in the tuning procedure, from initial orbit establishment to final IP spot-size tuning. Through a Monte Carlo study of 100's of simulation seeds we find we can achieve a spot-size within ~10% of the design optics value in at least 75% of cases. We also ran a simulation to study the long-term performance with the use of beam-based feedbacks.
TUOCM01	First Measurements of the Longitudinal Bunch Profile at SLAC Using Coherent Smith-Purcell Radiation at 28GeV	1026
	V. Blackmore, G. Doucas, B. Ottewell, C. Perry OXFORDphysics, Oxford, Oxon R. Arnold, S. Molloy, M. Woods SLAC, Menlo Park, California M. F. Kimmitt University of Essex, Physics Centre, Colchester
	Coherent Smith-Purcell radiation has been demonstrated as a technique for measuring the longitudinal profile of charged particles bunches in the low to intermediate energy range. However, with the advent of the International Linear Collider, the need has arisen for a non-invasive method of measuring the bunch profile at extremely high energies. Smith-Purcell radiation has been used for the first time in the multi-GeV regime to measure the longitudinal profile of the 28GeV SLAC beam. The experiment has both successfully determined the bunch length, and has also demonstrated its sensitivity to bunch profile changes. The challenges associated with this technique, and its prospects as a diagnostic tool are reported here.
	Slides
TUPP016	A Flight Simulator for ATF2 - A Mechanism for International Collaboration in the Writing and Deployment of Online Beam Dynamics Algorithms	1562
	G. R. White, S. Molloy, A. Seryi SLAC, Menlo Park, California P. Bambade, Y. Renier LAL, Orsay S. Kuroda KEK, Ibaraki D. Schulte, R. Tomas CERN, Geneva
	The goals of ATF2 are to test a novel compact final focus optics design with local chromaticity correction intended for use in future linear colliders. The newly designed extraction line and final focus system will be used to produce a 37nm vertical waist from an extracted beam from the ATF ring of ~30nm vertical normalised emittance, and to stabilise it at the IP-waist to the ~2nm level. Static and dynamic tolerances on all accelerator components are very tight; the achievement of the ATF2 goals is reliant on the application of multiple high-level beam dynamics algorithms to align and tune the electron beam in the extraction line and final focus system. Much algorithmic development work has been done in Japan and by colleagues in collaborating nations in North America and Europe. We describe here development work towards realising a 'flight simulator' environment for the shared development and implementation of beam dynamics code. This software exists as a 'middle-layer' between the lower-level control systems (EPICS and V-SYSTEM) and the multiple higher-level beam dynamics modeling tools in use by the three regions (SAD, Lucretia and PLACET).
WEPP163	Measurements of Collimator Wakefields at End Station A	2868
	J.-L. Fernandez-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire S. Molloy SLAC, Menlo Park, California J. D.A. Smith Cockcroft Institute, Warrington, Cheshire N. K. Watson Birmingham University, Birmingham
	The angular kicks imparted to an electron beam with energy of 28.5 GeV when it passes through a collimator jaw with a certain offset, generating a wakefield, were measured in End Station A (ESA) in SLAC for fifteen different collimator configurations of geometry and material. Some configurations were chosen in order to compare with previous measurements while others served to study the effect of geometry and taper angles (geometrical contribution to the wakefield) and the effect of the material resistivity (resistive contribution) to the kick. This paper summarises the final experimental results. The reconstructed kick factor is compared to analytical calculations and simulations.