Author: Uriot, D.
Paper Title Page
WEA1WB02
 Characterization of High Intensity Beams in Linacs  
 
  • P.A.P. Nghiem, N. Chauvin
    CEA/IRFU, Gif-sur-Yvette, France
  • L. Ducrot
    CEA/DSM/IRFU, France
  • W. Simeoni
    IF-UFRGS, Porto Alegre, Brazil
  • D. Uriot
    IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France
  • M. Valette
    CERN, Geneva, Switzerland
  
  For high intensity linacs, beam particle distributions are in most cases far from Gaussian ones. Furthermore, the distribution shapes drastically differ from a linac to another and significantly change along a given linac. For those reasons, classical RMS parameters like beam envelope or emittance are no longer enough for characterizing the beam as soon as comparison or evolution of beam quality is in view. This paper presents three alternative ways to characterize more suitably a high intensity beam: 6D coordinates of the actual number of particles, projections of the distribution onto a few axes, RMS parameters of the core and of the halo separately. The advantages and drawbacks of each method are then discussed in terms of beam representativeness, data weight and physics insight.  
slides icon Slides WEA1WB02 [17.204 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THP1WB02
 Beam Dynamics in Low Energy Beam Lines with Space Charge Compensation  
 
  • N. Chauvin, N. Pichoff, D. Uriot
    IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France
  • A. Chancé
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • F. Gérardin
    CEA/IRFU, Gif-sur-Yvette, France
  
  The study of the dynamics of low energy beam transport (LEBT) line is one of the major challenges in the high intensity hadron accelerators field. At low energy, the beam transport is dominated by the charge space field which in many cases can induce a halo formation, emittance growth and eventually beam losses. Moreover, beam dynamics in LEBT features a unique specificity: space charge compensation induced by ionisation of the residual gas by the propagating beam. In order to attempt to reach a better understanding of space charge compensation and particles dynamics in LEBTs, extensive numerical simulations using the PIC code Warp have been performed. Simulation results for light ions beams propagating in the LEBT of the IFMIF-LIPAc and MYRRHA accelerator will be presented and compared to experimental results.  
slides icon Slides THP1WB02 [6.063 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THA1WE04 ESS nBLM: Beam Loss Monitors based on Fast Neutron Detection 404
 
  • T. Papaevangelou
    CEA/IRFU, Gif-sur-Yvette, France
  • H. Alves, S. Aune, J. Beltramelli, Q. Bertrand, T. Bey, B. Bolzon, N. Chauvin, M. Combet, D. Desforge, M. Desmons, Y. Gauthier, E. Giner-Demange, A. Gomes, F. Gougnaud, F. Harrault, F. J. Iguaz Gutierrez, T.J. Joannem, M. Kebbiri, C. Lahonde-Hamdoun, P. Le Bourlout, Ph. Legou, O. Maillard, A. Marcel, C. Marchand, Y. Mariette, J. Marroncle, V. Nadot, M. Oublaid, G. Perreu, O. Piquet, B. Pottin, Y. Sauce, J. Schwindling, L. Segui, F. Senée, R. Touzery, G. Tsiledakis, O. Tuske, D. Uriot
    IRFU, CEA, University Paris-Saclay, Gif-sur-Yvette, France
  • I. Dolenc Kittelmann, R.J. Hall-Wilton, C. Höglund, L. Robinson, T.J. Shea, P. Svensson
    ESS, Lund, Sweden
  • V. Gressier
    IRSN, Saint-Paul-Lez-Durance, France
  • K. Nikolopoulos
    Birmingham University, Birmingham, United Kingdom
  • M. Pomorski
    CEA/DRT/LIST, Gif-sur-Yvette Cedex, France
  
  A new type of Beam Loss Monitor (BLM) system is being developed for use in the European Spallation Source (ESS) linac, primarily aiming to cover the low energy part (proton energies between 3-100 MeV). In this region of the linac, typical BLM detectors based on charged particle detection (i.e. Ionization Cham-bers) are not appropriate because the expected particle fields will be dominated by neutrons and photons. Another issue is the photon background due to the RF cavities, which is mainly due to field emission from the electrons from the cavity walls, resulting in brems-strahlung photons. The idea for the ESS neutron sensi-tive BLM system (ESS nBLM) is to use Micromegas detectors specially designed to be sensitive to fast neutrons and insensitive to low energy photons (X and gammas). In addition, the detectors must be insensitive to thermal neutrons, because those neutrons may not be directly correlated to beam losses. The appropriate configuration of the Micromegas operating conditions will allow excellent timing, intrinsic photon back-ground suppression and individual neutron counting, extending thus the dynamic range to very low particle fluxes.  
slides icon Slides THA1WE04 [3.267 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THA1WE04  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)