Keyword: injection
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MOCOBK02 Present Status of FLNR (JINR) ECR Ion Sources ion, ion-source, cyclotron, ECR 17
 
  • S.L. Bogomolov, V.B. Bekhterev, V.M. Drobin, A. Efremov, B. Gikal, G.G. Gulbekyan, Yu.K. Kostyukhov, N. Lebedev, V.N. Loginov, V.V. Seleznev, Yu. Yazvitsky
    JINR, Dubna, Moscow Region, Russia
 
  Six ECR ion sources have been operated in the Flerov Laboratory of Nuclear Reactions (JINR). Two 14 GHz ECR ion sources (ECR4M and DECRIS-2) supply various ion species for the U400 and U400M cyclotrons correspondingly for experiments on the synthesis of heavy and exotic nuclei using ion beams of stable and radioactive isotopes. The 18 GHz DECRIS-SC ion source with superconducting magnet system produce ions from Ar up to W for solid state physics experiments and polymer membrane fabrication at the CI-100 cyclotron. The third 14 GHz ion source DECRIS-4 with “flat” minimum of the axial magnetic field is used as a stand alone machine for test experiments and also for experiments on ion modification of materials. The other two compact ECR ion sources with all permanent magnet configuration have been developed for the production of single charged ions and are used at the DRIBs installation and at the MASHA mass-spectrometer. In this paper, present status of the ion sources, recent developments and plans for modernization are reported. Also the results of the preliminary test of the DECRIS-SC2 ECR source will be presented.  
slides icon Slides MOCOBK02 [11.671 MB]  
 
MOCOCK04 Measurement of the Sixty GHz ECR Ion Source using Megawatt Magnets - SEISM Magnetic Field Map resonance, extraction, ECR, ion-source 33
 
  • M. Marie-Jeanne, J. Jacob, T. Lamy, L. Latrasse
    LPSC, Grenoble Cedex, France
  • F. Debray, J. Matera, R. Pfister, C. Trophime
    GHMFL, Grenoble, France
 
  LPSC has developed a prototype of 60GHz Electron Cyclotron Resonance (ECR) Ion Source called SEISM. The first 60GHz magnetic structure is based on a cusp geometry, using resistive polyhelix coils designed in collaboration with the Intense Magnetic Fields National Laboratory (LNCMI). A dedicated test bench helices coils in their tanks, electrical, and water cooling environment was built to study the mechanics, thermal behaviour and magnetic field characteristics obtained at various current levels. During the last months, measurements were performed for several magnetic configurations, with up to 7000A applied on the injection/extraction coils set. The magnetic field achieved at 13000A is expected to allow 28GHz ECR condition. However, cavitation issues that appeared around 7000A are to be solved before carrying on with the tests. This contribution will recall some of the crucial steps in the prototype fabrication, and show preliminary results from the measurements at 7000A. Possible explanations for the discrepancies observed between the results and the simulation will be given.  
slides icon Slides MOCOCK04 [3.243 MB]  
 
MOPOT006 Ionization Efficiency of a COMIC Ion Source Equipped With a Quartz Plasma Chamber ion, plasma, ion-source, target 51
 
  • P. Suominen, T. Stora
    CERN, Geneva, Switzerland
  • J. Médard, P. Sortais
    LPSC, Grenoble, France
 
  The ISOLDE facility at CERN produces a wide range of radioactive ion beams due to a long history on target and ion source development. Because the radioactive isotope production is very limited, the most important ion source parameters are high ionization efficiency, selectivity and reliable operation under intense radiation. Currently used ion sources (mainly laser (RILIS [1]) and arc discharge -type ion sources (VADIS [2]) do not efficiently ionize light noble gases, such as helium, and molecules, such as CO, N2 and NO. These beams were previously planned to be produced with 1+ ECR ion sources operating at 2.45 GHz (for example MINIMONO [3]) but due to new and more efficient RF coupling of COMIC-type ion sources [4], we expect to advance in 2.45 GHz ECRIS utilization for radioactive beam production. The new COMIC source designed by LPSC, Grenoble incorporates special features such as a plasma chamber fully made of quartz (Q-COMIC). This should provide chemically good conditions for molecular ion beam production, especially for carbon. This paper presents the first ionization efficiency measurements of the Q-COMIC.
[1] V.N. Fedosseev, et al, Nucl. Instrum. Methods Phys. Res. B 266/19-20 (2008) 4378.
[2] PhD thesis, univ. polyt. Bucarest, L. Penescu (2009).
[3] F. Wenander, W. Farabolini, G. Gaubert, P. Jardin, J. Lettry, Nucl. Phys. A, 746 (2004) 659.
[4] P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81 (2010) 02B314.
 
poster icon Poster MOPOT006 [0.697 MB]  
 
MOPOT011 DRAGON: a New 18 GHz RT ECR Ion Source with a Large Plasma Chamber ECRIS, plasma, sextupole, extraction 58
 
  • W. Lu, D. Xie, X.Z. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  • W. Lu
    Graduate School of the Chinese Academy of Sciences, Beijing, People's Republic of China
  • L. Ruan, F.C. Song, B. Xiong, S. Yu, J. Yuan
    IEE, Beijing, People's Republic of China
 
  Building a strong radial magnetic field with a permanent hexapole magnet for an ECRIS is extremely challenging so that the conventional wisdom requires a small but not optimal plasma chamber that is typically of ID less or equal to 80 mm. A new 18 GHz RT ECR ion source, DRAGON, has been designed with a large bore permanent hexapole and source construction has begun at IMP. Its plasma chamber is of ID of 126 mm, the same as that of the superconducting ion source SECRAL, with maximum radial field strength reaching 1.5 Tesla at the plasma chamber wall. The overall magnetic strengths of DRAGON, with maximum axial fields of 2.7 Tesla at the injection and 1.3 Tesla at the extraction, are very similar to those of SECRAL operating at 18 GHz and hopefully the SECRAL performance. The source solenoid magnet coils are cooled by an evaporative coolant at about 50 degree C. In addition, the source is thickly insulated for beam extraction at 50 kV and higher voltage up to 100 kV can be explored. This article will present the design details and discussions of this new ion source.  
poster icon Poster MOPOT011 [0.563 MB]  
 
MOPOT016 A Low Power Survey of Radial-Offset Axial Sputtering and High Intensity Uranium Production from Axial Sputtering in SuSI target, plasma, survey, ion 69
 
  • D.G. Cole, G. Machicoane, T. Ropponen, L.T. Sun, L. Tobos
    NSCL, East Lansing, Michigan, USA
 
  Prototype sputtering hardware has been tested in the SuSI ion source and early uranium ion production is discussed. Also, results of a low power survey of axial sputtering, to test sputtering efficiency at incremental radial offsets from on axis position, is reported.  
poster icon Poster MOPOT016 [2.672 MB]  
 
MOPOT017 Tests of a New Axial Sputtering Technique in an ECRIS plasma, ECRIS, ECR, ion 72
 
  • R.H. Scott, R.C. Pardo, R.C. Vondrasek
    ANL, Argonne, USA
 
  Funding: This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357.
Axial and radial sputtering techniques have been used over the years to create beams from an ECRIS at multiple accelerator facilities. Operational experience has shown greater beam production when using the radial sputtering method versus axial sputtering. At Argonne National Laboratory, previous work with radial sputtering has demonstrated that the position of the sputter sample relative to the plasma chamber wall influences sample drain current, beam production and charge state distribution. The possibility of the chamber wall acting as a ground plane which influences the sputtering of material has been considered, and an attempt has been made to mimic this possible ground plane effect with a coaxial sample introduced from the injection end. Results of these tests will be shown as well as comparisons of outputs using the two methods.
 
poster icon Poster MOPOT017 [1.506 MB]  
 
TUPOT006 Using Mass-Flow Controllers for Obtaining Extremely Stable ECR Ion Source Beams ion, ECR, controls, ion-source 127
 
  • X. Donzel, W. Bougy, B.N. Brionne, G. Gaubert, A. Sineau, O. Tasset, C. Vallerand, A.C.C. Villari
    PANTECHNIK, BAYEUX, France
  • R. Leroy
    GANIL, Caen, France
 
  Beam stability and reproducibility is of paramount importance in applications requiring precise control of implanted radiation dose, like in the case of Hadrontherapy. The beam intensity over several weeks or months should be kept constant. Moreover, the timing for changing the nature of the beam and, as a consequence, the tuning of the source should be minimized. Standard valves usually used in conjunction of ECR ion sources have the disadvantage of controlling the conductance, which can vary significantly with external conditions, like ambient temperature and inlet pressure of the gas. The use of flow controllers is the natural way for avoiding these external constraints. In this contribution we present the results obtained using a new model of Mass-flow controller in the source Supernanogan, for production of C4+ and H3+ beams. Extremely stable beams (± 2.5%) without retuning of the source over several weeks could be obtained. The reproducibility of the source tuning parameters could also be demonstrated.  
poster icon Poster TUPOT006 [4.386 MB]  
 
WECOBK02 Recent Performance of the ANL ECR Charge Breeder plasma, ion, ECR, extraction 181
 
  • R.C. Vondrasek, A. Kolomiets, R.C. Pardo, R.H. Scott
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
The construction of the Californium Rare Ion Breeder Upgrade (CARIBU), a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS), is nearing completion. The facility will use fission fragments, with charge 1+ or 2+, from a 1 Ci 252Cf source; thermalized and collected into a low-energy particle beam by a helium gas catcher. An existing ATLAS ECR ion source was modified to function as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. A surface ionization source or an RF discharge source provide beams for charge breeding studies. An achieved efficiency of 11.9% for 85Rb19+, with a breeding time of 200 msec, and 15.6% for 84Kr17+ has been realized. Both results are with the source operating with two RF frequencies (10.44 + 11.90 GHz). After modification to the injection side iron plug, the charge breeder has been operated at 50 kV, a necessary condition for the resolution of the isobar separator.
 
slides icon Slides WECOBK02 [3.351 MB]  
 
WECOBK03 Fine Frequency Tuning of the PHOENIX Charge Breeder Used as a Probe for ECRIS Plasmas ion, plasma, ECR, ion-source 184
 
  • T. Lamy, J. Angot, M. Marie-Jeanne, J. Médard, P. Sortais, T. Thuillier
    LPSC, Grenoble Cedex, France
  • A. Galatà
    INFN/LNL, Legnaro (PD), Italy
  • H. A. Koivisto, O.A. Tarvainen
    JYFL, Jyväskylä, Finland
 
  Fine frequency tuning of ECR ion sources is a main issue to optimize the production of multiply charged ion beams. The PHOENIX charge breeder operation has been tested in the range 13,75 - 14,5 GHz with an HF power of about 400 W. The effect of this tuning is analyzed by measuring the multi-ionization efficiency obtained for various characterized injected 1+ ion beams (produced by the 2.45 GHz COMIC source). The 1+/n+ method includes the capture and the multi ionization processes of the 1+ beam and may be considered as a plasma probe. The n+ spectra obtained could be considered, in first approach, as an image of the plasma of the charge breeder. However, in certain conditions it has been observed that the injection of a few hundreds of nA of 1+ ions (i.e.: Xe1+) in the plasma of the charge breeder, is able to destroy the charge state distribution of the support gas (i.e.: up to 40 % of O6+ and O7+ disappears). The study of this phenomenon will be presented along with plasma potential measurements for various charge states. This study may help to understand the ECRIS creation (or destruction) of highly charged ions.  
slides icon Slides WECOBK03 [7.745 MB]