Keyword: emittance
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MOCOBK01 ECR Ion Sources for the Facility for Rare Isotope Beams (FRIB) Project at Michigan State University ion, ion-source, ECR, linac 14
 
  • G. Machicoane, M. Doleans, O.K. Kester, T. Ropponen, L.T. Sun, X. Wu
    NSCL, East Lansing, Michigan, USA
  • D. Leitner
    LBNL, Berkeley, California, USA
  • E. Pozdeyev, E. Tanke
    FRIB, East Lansing, Michigan, USA
 
  Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661
Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain key understanding in nuclear science and in particular regarding the properties of nuclei far from the valley of stability or the nuclear processes in the universe. In addition it will also allow experimenters to test fundamental symmetries. The production of rare isotopes with FRIB will be achieved, using a heavy ion driver linac that will accelerate a stable isotope beam to 200 MeV/u and deliver it on a fragmentation target. FRIB aims to reach a primary beam power of 400 kW for light to heavy elements up to Uranium. To meet the intensity requirement two high performance ECR ion sources operating at 28 GHz will be used to produce high intensity of medium to high charge state ion beams. Plans regarding initial beam production with the ECR ion sources and beam transport through the front end will be discussed.
 
slides icon Slides MOCOBK01 [3.259 MB]  
 
MOPOT012 Tests of the Versatile Ion Source (VIS) for High Power Proton Beam Production extraction, plasma, permanent-magnet, proton 61
 
  • S. Gammino, G. Castro, L. Celona, G. Ciavola, D. Mascali, R. Miracoli
    INFN/LNS, Catania, Italy
  • G. Adroit, O. Delferrière, R. Gobin, F. Senée
    CEA/DSM/IRFU, France
  • F. Maimone
    GSI, Darmstadt, Germany
 
  The sources adapted to beam production for high power proton accelerators must obey to the request of high brightness, stability and reliability. The Versatile Ion Source (VIS) is based on permanent magnets (maximum value around 0.1 T on the chamber axis) producing an off-resonance microwave discharge. It operates up to 75 kV without a bulky high voltage platform, producing several tens of mA of proton beams and monocharged ions. The microwave injection system and the extraction electrodes geometry have been designed in order to optimize the beam brightness. Moreover, the VIS source ensures long time operations without maintenance and high reliability in order to fulfil the requirements of the future accelerators. A description of the main components and of the source performances will be given. A brief summary of the possible options for next developments of the project will be also presented, particularly for pulsed mode operations, that are relevant for some future projects (e.g. the European Spallation Source of Lund).  
 
TUCOAK02 Trace Space Reconstruction From Pepperpot Data ion, simulation, beam-transport, ECRIS 78
 
  • H.R. Kremers, J.P.M. Beijers, S. Brandenburg, V. Mironov, J. Mulder, S. Saminathan
    KVI, Groningen, The Netherlands
 
  We use a pepperpot emittance meter to determine the full transverse trace-space distribution of low-energy ion beams. One of the problems encountered with our emittance meter is that the correlation between the measured ion images and the holes in the pepperplate is somewhat ambiguous caused by the convoluted character of the trace-space distribution. In this paper we describe a method to solve this problem and illustrate it with measurements of the 4d transverse trace-space distribution behind the analyzing magnet of a 21 keV He1+ beam extracted from the KVI-AECR ion source. From these measurements together with ion-transport simulations we conclude that second-order aberrations in the analyzing magnet cause a significant increase in the effective beam emittance.  
slides icon Slides TUCOAK02 [3.474 MB]  
 
TUCOAK03 Plasma-to-Target WARP Simulations of Uranium Beams Extracted from VENUS Compared to Emittance Measurements and Beam Images ion, simulation, extraction, ion-source 81
 
  • D. Winklehner, J.Y. Benitez, D. Leitner, M.M. Strohmeier, D.S. Todd
    LBNL, Berkeley, California, USA
  • D.P. Grote
    LLNL, Livermore, California, USA
 
  The superconducting ECR ion source VENUS was built as injector for the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL) and as prototype injector for the Facility for Rare Isotope Beams (FRIB) in Michigan. This work presents the latest results of an ongoing effort to simulate both, the extraction from ECR ion sources, and the Low Energy Beam Transport (LEBT). Its aim is to help understand the influence of parameters like initial ion distributions at the extraction aperture, ion temperatures and beam neutralization on the quality of the beam and to provide a design-tool for increasing the efficiency of the extraction- and transport-system. The initial conditions (i.e. spatial- and velocity-distribution of the ions prior to extraction from the ion source) are obtained semi-empirically by tracking the ions of different species from sputter marks on the biased disk on the far end of the source to the extraction region by following the magnetic field lines and scaling the Larmor radii of the ions appropriately. Extraction from the plasma and consequently the source is then simulated with the versatile WARP simulation code. The same code is also used for the actual simulation of ion transport through the beam line. Simulations of multi-species Uranium beams with different drain currents, initial ion temperatures and levels of neutralization in the beam line are compared to each other and to emittance measurements and beam profiles of VENUS beams.  
slides icon Slides TUCOAK03 [2.382 MB]  
 
TUCOAK04 Production of Highly Charged U Ion Beam from RIKEN SC-ECRIS ion, ECRIS, extraction, target 84
 
  • Y. Higurashi, M. Fujimaki, A. Goto, H. Haba, E. Ikezawa, O. Kamigaito, M. Kase, M. Komiyama, T. Nakagawa, J. Ohnishi, Y. Watanabe
    RIKEN Nishina Center, Wako, Japan
  • T. Aihara, M. Tamura, A. Uchiyama
    SHI Accelerator Service Ltd., Tokyo, Japan
 
  In 2008, we successfully produced 345 MeV/u U beam (~0.4 pnA on target) for RIKEN RIBF project. However, to meet the requirement of the RIBF (primary beam intensity of 1pμA on target), we still need to increase the beam intensity. To increase the beam intensity of U ion, we started to make a test experiments for production of U ion beam from the new SC-ECRIS. In this experiment, we produced 2~1.5 pμA of medium charge state U ion (ex., 55 eμA of U31+, 57 eμA of U27+) at the RF power of 1.2 kW with sputtering method. For testing the effect of the ionized gas on the U ion beam, we chose Ar, Ar + O2 and O2 gas for producing U ion beam. In this experiment, we observed that the beam intensity of lower charge state of U ion beam (<33+) was increased and the emittance of the U ion beam was decreased from ~0.1 π.mm mrad (1rms) to 0.05 π.mm mrad with adding Ar gas to O2 gas. Using this method, we supplied U35+ beam for ~1 month without break for the RIBF experiment. In this contribution, we present the experimental results for production of U ion beam from SC-ECRIS in detail and future plan to increase the U ion beam intensity.  
slides icon Slides TUCOAK04 [1.709 MB]  
 
TUPOT010 Effects of Microwave Frequency Fine Tuning on the Performance of JYFL 14 GHz ECRIS plasma, ion, ion-source, ECRIS 137
 
  • V.A. Toivanen, V.P. Aho, J. Ärje, P. Jones, J.A. Kauppinen, H. A. Koivisto, P. Peura, O.A. Tarvainen
    JYFL, Jyväskylä, Finland
  • L. Celona, G. Ciavola, S. Gammino
    INFN/LNS, Catania, Italy
  • A. Galatà
    INFN/LNL, Legnaro (PD), Italy
  • D. Mascali
    CSFNSM, Catania, Italy
  • T. Ropponen
    NSCL, East Lansing, Michigan, USA
 
  Measurements have been carried out at Department of Physics, University of Jyväskylä (JYFL) to study the effects of microwave frequency fine tuning on the performance of JYFL 14 GHz electron cyclotron resonance ion source. The frequency was varied within an 85 MHz band around the normal operation frequency of 14.085 GHz. The radial bremsstrahlung emission was measured for plasma diagnostics purposes and mass separated ion beam currents extracted from the ion source were recorded at the same time. Also, beam quality studies were conducted by measuring the ion beam emittance and shape with and without enhanced space charge compensation. The obtained results are presented and possible origins of seen phenomena in measured quantities are discussed.  
poster icon Poster TUPOT010 [0.678 MB]  
 
TUPOT017 CEA/Saclay Light Ion Sources Status and Developments ion, plasma, ion-source, extraction 156
 
  • R. Gobin, C.M. Mateo, S. Nyckees
    CEA/IRFU, Gif-sur-Yvette, France
  • G. Adroit, G. Bourdelle, N. Chauvin, O. Delferrière, Y. Gauthier, P. Girardot, F. Harrault, C. Marolles, B. Pottin, Y. Sauce, F. Senée, O. Tuske, T.V. Vacher, C. Van Hille
    CEA/DSM/IRFU, France
 
  After several years of high intensity light ion beam production with the SILHI source, CEA Saclay is now involved in the construction of different injectors dedicated to large infrastructures like IFMIF or Spiral 2. Other installations are also interested by high intensity ion sources like ESS or FAIR. Such machines plan to produce and accelerate proton or deuteron beams in pulsed or continuous mode. The SILHI source, based on ECR plasma generation, already demonstrated its performance in both modes. As a consequence, at present time the construction of 2 new injectors for Spiral 2 and IFMIF (source and low energy beam lines) is in progress at CEA/Saclay. This article will report on the status of both installations. It will also point out on additional developments presently under progress for high intensity beam characterization or plasma production understanding. Such developments are mainly done with the new BETSI test bench operating for several months.  
poster icon Poster TUPOT017 [2.020 MB]  
 
THCOAK01 A Correction Scheme for the Hexapolar Error of an Ion Beam Extracted from an ECRIS ion, simulation, plasma, extraction 191
 
  • P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert
    GSI, Darmstadt, Germany
 
  The extraction of any ion beam from ECRIS is determined by the good confinement of such ion sources. It has been shown earlier, that the ions are coming from these places, where the confinement is weakest. The assumption that the low energy ions are strongly bound to the magnetic field lines require furthermore, that only these ions which start on a magnetic field line which go through the extraction aperture can be extracted. Depending on the setting of the magnetic field, these field lines may come from the loss lines at plasma chamber radius. Because the longitudinal position of these field lines depends on the azimuthal position at the extraction electrode, the ions are extracted from different magnetic flux densities. Whereas the solenoidal component is not curable, the hexapolar component can be compensated by an additional hexapole after the first beam line focusing solenoid. The hexapole has to be rotatable in azimuthal direction and moveable in longitudinal direction. For a good correction the beam needs to have such a radial phase space distribution, that the force given by this hexapole act on the aberrated beam exactly in such a way to create a linear distribution after that corrector.  
slides icon Slides THCOAK01 [1.115 MB]  
 
THCOAK03 Dipole Magnet Optimization for High Efficiency Low Energy Beam Transport simulation, ECRIS, extraction, ion 197
 
  • S. Saminathan, J.P.M. Beijers, S. Brandenburg, V. Mironov, J. Mulder
    KVI, Groningen, The Netherlands
 
  Losses in the low-energy beam transport line from KVI-AECRIS to AGOR cyclotron are estimated to be around 50%. Numerical simulations of the beam transport were performed using the tracing code LORENTZ-3D. It was found that most of the losses are due to second order optical aberrations in the 110-degree analyzing magnet. These aberrations result in an increase of the effective emittance in both horizontal and vertical directions. We will show that by suitably modifying the magnet pole surfaces the second-order aberrations can be compensated to a large extent resulting in a substantially lower effective emittance of the transported beam.  
slides icon Slides THCOAK03 [1.102 MB]