• A.S. Aryshev, N. Terunuma, J. Urakawa
  KEK, Ibaraki
• S.T. Boogert, V. Karataev
  JAI, Egham, Surrey
• D.F. Howell
  OXFORDphysics, Oxford, Oxon

Optical Transition Radiation (OTR) appearing when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in various facilities worldwide. The resolution of the conventional monitors is defined by so-called Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. In our experiment we managed to create a system which can practically measure the PSF distribution. We demonstrated that is it is non-uniform. In this paper we represent the development of a novel sub-micrometer electron beam profile monitor based on the measurements of the PSF structure. The visibility of the structure is sensitive to micrometer electron beam dimensions. In this report we shall represent the recent experimental results. The future plans on the optimization of the monitor will also be presented.

• T. Aumeyr, G.A. Blair, S.T. Boogert, G.E. Boorman, A. Bosco
  JAI, Egham, Surrey
• K. Balewski, E. Elsen, V. Gharibyan, G. Kube, S. Schreiber, K. Wittenburg
  DESY, Hamburg

The PETRA-III Laser-wire, a Compton scattering beam size measurement system at DESY, uses an automated mirror to scan a Q-switched laser across the electron beam and is developed from the system previously operated at PETRA-II. This paper reports on recent upgrades of the optics, vacuum vessel and data acquisition. First beam profile measurements are also presented.

• S.T. Boogert, G.E. Boorman, C. Swinson
  JAI, Oxford
• R. Ainsworth, S. Molloy
  Royal Holloway, University of London, Surrey
• A.S. Aryshev, Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
  KEK, Ibaraki
• J.C. Frisch, J. May, D.J. McCormick, J. Nelson, T.J. Smith, G.R. White, M. Woodley
  SLAC, Menlo Park, California
• A. Heo, E.-S. Kim, H.-S. Kim, Y.I. Kim
  Kyungpook National University, Daegu
• A. Lyapin
  UCL, London
• H.K. Park
  KNU, Deagu
• M.C. Ross
  Fermilab, Batavia
• S. Shin
  PLS, Pohang

The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a lepton linear collider. The ATF2 beam-line is instrumented with a total of 38 C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitizers. The current status of the BPM system is described, with a focus on operational techniques and performance.

• M.D. Hildreth
  University of Notre Dame, Notre Dame
• A.S. Aryshev
  Royal Holloway, University of London, Surrey
• S.T. Boogert
  JAI, Egham, Surrey
• Y. Honda, T. Tauchi, N. Terunuma
  KEK, Ibaraki
• G.R. White
  SLAC, Menlo Park, California

The demonstration of the stability of the position of the focused beam is a primary goal of the ATF2 project. We have installed a laser interferometer system that will eventually correct the measurement of high-precision Beam Position Monitors used in the ATF2 Final Focus Steering Feedback for mechanical motion or vibrations. Here, we describe the installed system and present preliminary data on the short- and long-term mechanical stability of the BPM system.

• Y.I. Kim, A. Heo, E.-S. Kim
  Kyungpook National University, Daegu
• S.T. Boogert
  Royal Holloway, University of London, Surrey
• Y. Honda, T. Tauchi, N. Terunuma
  KEK, Ibaraki
• J. May, D.J. McCormick, T.J. Smith
  SLAC, Menlo Park, California

Nanometer resolution Beam Position Monitors have been developed to measure and control beam position stability at the interaction point region of ATF2. The position of the beam focused has to be measured within a few nanometer resolution at the interaction point. In order to achieve this performance, electronics for this BPM was developed. Every component of the electronics have been simulated and checked by local test and using beam signal. We will explain each component and define their working range. Then, we will show the performance of the electronics measured with beam signal.

• S. Molloy, S.T. Boogert
  Royal Holloway, University of London, Surrey

Serpentine is a Python library, written for the purpose of simulating charged particle accelerators. It has been written to allow for the simulation of both rings and single-shot machines in a light-weight way (i.e. without requiring significant computational resources for typical calculations, such as the determination of transfer matrices, or matching of Twiss parameters), and has been structured to be highly modular (i.e. allowing extension of the simulations to include effects not already included in the base installation). Through the use of the Universal Accelerator Parser (UAP), Serpentine has no need for a new lattice representation, and allows access to any lattice format understood by UAP. The operation of this code on several complex accelerator designs is demonstrated.