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Pozimski, J. K.

Paper Title Page
MOPC144 Installation of the Front End Test Stand High Performance H- Ion Source at RAL 412
 
  • D. C. Faircloth, M. H. Bates, S. R. Lawrie, A. P. Letchford, M. Perkins, M. E. Westall, M. Whitehead, P. Wise, T. Wood
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  
  The RAL Front End Test Stand (FETS) is being constructed to demonstrate a chopped H- beam of up to 60 mA at 3 MeV with 50 pps and sufficiently high beam quality for future high-power proton accelerators (HPPA). This paper details the first stage of construction- the installation of the ion source.  
TUPC058 Laser-based Ion Beam Diagnostics for the Front End Test Stand at RAL 1188
 
  • D. A. Lee, J. K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  
  The RAL Front End Test Stand is being constructed to demonstrate that a chopped H- beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality as required for future high-power proton accelerators can be produced. Because of the high beam power and a preference for online beam monitoring non-intrusive, non-destructive beam diagnostics are desirable. Two novel instruments, based on the photo-detachment of the outer electron of the H- ions with a laser, are being developed to precisely determine the transverse beam density distribution and the beam emittance at full beam power. This paper discusses the proposed experimental layout of the devices and the progress that has been made towards realizing them. The design of the optical system is presented along with measurements of the laser beam propagation for the beam density distribution experiment. Investigations of the influence of laser beam misalignment along with measurements of the positioning accuracy of movable stages that will be used are given in light of the total expected errors.  
MOPC142 Study of the Post Extraction Acceleration Gap in the ISIS H- Penning Ion Source 406
 
  • D. C. Faircloth, M. Whitehead, T. Wood
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon
  
  The RAL Front End Test Stand (FETS) is being constructed to demonstrate a chopped H- beam of up to 60 mA at 3 MeV with 50 pps and sufficiently high beam quality for future high-power proton accelerators (HPPA). The injection energy into the RFQ will be in the range of 50 to 70 keV whereas the standard ISIS H- Penning ion source operates at 35 keV, therefore the post extraction acceleration voltage must be increased. In order to finalise the design of the FETS post extraction system, a study is conducted on the Ion Source Development Rig (ISDR) at ISIS. This study shows how beam transport is affected by different post extraction acceleration voltages and gap lengths. Beam, current, profile and emittance measurements are presented along with theoretical calculations.  
MOPC150 Modifications to the Analysing Magnet in the ISIS Penning Ion Source 427
 
  • S. R. Lawrie, D. C. Faircloth, A. P. Letchford, M. E. Westall, M. Whitehead, T. Wood
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • J. K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon
  
  A full 3D electromagnetic finite element analysis and particle tracking study is undertaken of the ISIS Penning surface plasma ion source using CST Particle Studio 2008. The existing 90° analysing magnet is found to have a magnetic field index of 1.3, causing beam divergence and contributing to beam loss. Different magnet pole piece geometries are modelled and the effect of space charge investigated. Based on this modelling, three new sets of poles are manufactured and tested on the Ion Source Development Rig. The results are presented herein.  
THPP012 Beam Injection Issues of FFAG for Particle Therapy 3401
 
  • T. Yokoi, J. H. Cobb, G. Morgan
    OXFORDphysics, Oxford, Oxon
  • M. J. Easton, J. K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London
  • K. J. Peach
    JAI, Oxford
  
  Spot scanning irradiation is a next generation treatment scheme of particle therapy. The pulsed beam of FFAG accelerator is well fitted to the treatment. In order to form a uniform dose distribution in the target volume, intensity modulation is a requirement in spot scanning and it requires special consideration in injection in order to realize short time treatment using the pulsed beam of the FFAG. In this paper, injection related issues of NS-FFAG are discussed from the point of particle therapy, especially for spot scanning.  
THPP024 Detailed Study of the RF Properties of the FETS RFQ Cold Model 3422
 
  • S. Jolly, A. Kurup, D. A. Lee, J. K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  • Y. Cheng
    IHEP Beijing, Beijing
  • A. P. Letchford
    STFC/RAL, Chilton, Didcot, Oxon
  
  A 324MHz four vane RFQ cold model has been built, as part of the development of a proton driver Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) in the UK. Previous measurements to determine the electric field profile were made using the bead-pull perturbation method: these measurements have been refined and expanded. New measurements of the electric field profile, Q-value and resonant modes are presented. Measurements of the fundamental frequency and Q-value of the RFQ as a result of modifications to the profile of the end flange inserts are also given. Finally, an experiment is outlined to determine the beam transmission properties of the cold model based on beam transport simulations with the General Particle Tracer package (GPT).  
THPP029 Status of the RAL Front End Test Stand 3437
 
  • A. P. Letchford, M. A. Clarke-Gayther, D. C. Faircloth, D. J.S. Findlay, S. R. Lawrie, P. Romano, P. Wise
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  • S. M.H. Al Sari, S. Jolly, A. Kurup, D. A. Lee, P. Savage
    Imperial College of Science and Technology, Department of Physics, London
  • J. Alonso, R. Enparantza
    Fundación Tekniker, Elbr (Guipuzkoa)
  • J. J. Back
    University of Warwick, Coventry
  • F. J. Bermejo
    Bilbao, Faculty of Science and Technology, Bilbao
  • C. Gabor, D. C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon
  • J. Lucas
    Elytt Energy, Madrid
  • J. Pasternak, J. K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon
  
  High power proton accelerators (HPPAs) with beam powers in the several megawatt range have many applications including drivers for spallation neutron sources, neutrino factories, waste transmuters and tritium production facilities. The UK's commitment to the development of the next generation of HPPAs is demonstrated by a test stand being constructed in collaboration between RAL, Imperial College London, the University of Warwick and the Universidad del Pais Vasco, Bilbao. The aim of the RAL Front End Test Stand is to demonstrate that chopped low energy beams of high quality can be produced and is intended to allow generic experiments exploring a variety of operational conditions. This paper describes the current status of the RAL Front End Test Stand.