Keyword: electron
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PO04 The Darmstadt Multi-Frequency Digital Low Level RF System in Pulsed Application controls, linac, cavity, low-level-rf 58
  • R. Eichhorn, U. Bonnes, C. Burandt, M. Konrad, P.N. Nonn
    TU Darmstadt, Darmstadt, Germany
  • G. Schreiber, W. Vinzenz
    GSI, Darmstadt, Germany
  Funding: Work supported by DFG through CRC 634 and by the BMBF under 06 DA 9024 I
Triggered by the need to control the superconducting cavities of the S-DALINAC, the development of a digital low level RF control system was started several years ago. The chosen design proved to be very flexible since other frequencies than the original 3 GHz may be adapted easily: The system converts the RF signal coming from the cavity (e. g. 3 GHz) down to the base band using a hardware I/Q demodulator. The base band signals are digitized by ADCs and fed into a FPGA where the control algorithm is implemented. The resulting signals are I/Q modulated before they are sent back to the cavity. Meanwhile, this system has been successfully operated on 3 GHz, 6 GHz and 325 MHz cavities, on normal and superconducting cavities as well as in cw or pulsed mode. This contribution will focus on the 325 MHz version built to control a pulsed prototype test stand for the p-LINAC at FAIR and possible extensions to even lower frequencies. We will present the architecture of the RF control system as well as results obtained during operation.
PO17 Simulation of Electron and Ion Dynamics in an EBIS ion, simulation, background, space-charge 97
  • L. Zhao, E.G. Evstati, J.S. Kim
    Far-Tech, Inc., San Diego, California, USA
  • E.N. Beebe, A.I. Pikin
    BNL, Upton, Long Island, New York, USA
  Funding: Grant supported by DOE office of Nuclear Physics
To model the dynamics of the ions in an Electron Beam Ion Source (EBIS), a time-dependent, self-consist particle-in-cell Monte Carlo code (EBIS-PIC) has been developed by FAR-TECH, Inc. The energetic background electron beam is modeled by PBGUNS ( by dividing the long beam path into several segments to resolve the big length-to-radius spatial scaling problem. The injected primary ions and ionized neutral gas ions are tracked using Monte Carlo method which includes the ionization, charge-exchange and Coulomb collisions with the electron beam and the neutral gas in the potential well, which is calculated by solving the Poisson equation each time step. EBIS-PIC has been able to predict the spatial and velocity space distributions and the evolution of the charge state distribution (CSD) of trapped ions in EBIS devices operating in fast or slow trapping mode. The physical model of EBIS-PIC code and the simulations of the trapping and charge-breeding of injected Cs+1 ions on the Test EBIS* at BNL will be presented. The simulation results have shown good consistency with the experiments.
* S. Kondrashev, J.G. Alessi, E.N.Beebe, C. Dickerson, P.N.Ostroumov, A. Pikin, G. Savard, NIMPR. A, 642 (2011), 18-24.
PO18 Tandem EBIS ion, injection, solenoid, extraction 101
  • A.I. Pikin, J.G. Alessi, E.N. Beebe, M. Okamura, D. Raparia, J. Ritter, L. Snydstrup
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported under the auspices of the US Department of Energy and the National Aeronautics and Space Administration.
A method to increase the ion beam intensity of RHIC EBIS by extending its ion trap into magnetic field of an additional superconducting solenoid is described. The strong axial support of the cold masses in these solenoids is required to place them on a common axis close to each other. Such configuration of solenoids allows to produce a long EBIS with a single electron gun, electron collector and injection system. Preliminary calculations of magnetic forces, magnetic field and potential distributions are presented along with proposed structure of the ion traps.
TUB01 Development of NRA System for a 1.7MV Tandem Accelerator-Human Resource Development Program for Nuclear Engineering, The University of Tokyo ion, resonance, target, proton 115
  • S. Ito, H. Matsuzaki, A. Morita
    The University of Tokyo, Tokyo, Japan
  The 1.7MV tandem accelerator (RAPID) at the University of Tokyo has been used for various research projects and educational studies since its installation in 1994. Recently RAPID has contributed to educational program for study by utilizing high sensitive ion beam analysis methods of the accelerator. In the fall of 2011, we newly developed a NRA (Nuclear Reaction Analysis) system with BGO scintillator. Detecting the resonant reaction 19F (p, αγ) 16O, a special student experimental class was successfully performed as a “Human resource development program for nuclear engineering”. The feature of this experiment is very few in advanced case study, which has performed with combine multiple ion beam correspond to a purpose for experiment. In this program students make their own samples for NRA analysis by ion implantation. Later in the year, RAPID will be relocated to the University of Tokyo (HIT facility) in Ibaraki prefecture to replace the 1MV tandem accelerator which was damaged by the Great East Japan Earthquake on March of 2011.  
slides icon Slides TUB01 [1.426 MB]  
TUB03 Terminal Voltage Stabilization of Pelletron Tandem Accelerator controls, feedback, ion, acceleration 124
  • N.R. Lobanov, M.C. Blacksell, P. Linardakis, D. Tsifakis
    Research School of Physics and Engineering, Australian National University, Canberra, Australia
  Funding: Heavy Ion Accelerators Education Investment Fund (EIF)
A conventional corona control terminal voltage stabiliser has been investigated on the ANU 14UD tandem accelerator. The fluctuations in the charge transport of electrostatic pelletron generator and their correlation with mechanical oscillations of the chains and terminal voltage ripple have been analysed. Emphasis is placed on the performance of the two-loop feedback system and on the tuning of this system to production of high energy-resolution beams. The transfer function for the corona regulation loop has been determined and examined. The system produces the beam position at the image slit of the 90 energy-analysing magnet with long-term stability equivalent to a few hundred volts rms fluctuation of the terminal voltage. The concept of novel fast control loop utilizing the high-frequency component from the image slits to control the voltage of the last gap of high-energy acceleration tube is discussed.
slides icon Slides TUB03 [4.693 MB]  
WEA02 Focusing of Intense Heavy Ion Beams with Plasma Lenses focusing, plasma, ion, heavy-ion 163
  • O. Meusel, M. Droba, U. Ratzinger, K. Schulte
    IAP, Frankfurt am Main, Germany
  Gabor lenses are a special type of plasma lens using a stable confined electron cloud for beam focusing. The electrons provide space charge neutralization of the beam traveling through the lens volume. At the same time a radial symmetric electrostatic self field focuses the beam mass independently. It is possible to control the density and distribution of the confined electrons providing variable focusing strength and moderate emittance growth of the beam. The knowledge of the behavior of the electron column inside this lens type is essential to understand the impact on beam transport. Therefore several diagnostic tools were developed to measure the electron cloud properties with and without ion beam propagation through Gabor lenses. Based on experimental results a new Gabor plasma lens has been designed for focusing heavy ion beams. A comparison of this lens type and a superconducting solenoid is planned at the low energy transport section of the GSI - High Current Test Injector (HOSTI).  
slides icon Slides WEA02 [1.572 MB]  
WEB01 Electron Beam Ion Sources, Traps, and Strings: Versatile Devices to Meet the High Charge State Ion Needs of Modern Facilities ion, ion-source, heavy-ion, collider 164
  • E.N. Beebe, J.G. Alessi, A.I. Pikin
    BNL, Upton, Long Island, New York, USA
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy, and by the National Aeronautics and Space Administration
Electron beam ion sources (EBIS) and its variants such as the electron beam ion trap (EBIT) and electron string ion source (ESIS) have been selected to provide highly charged ions for several atomic and nuclear physics facilities. Since the capture and breeding can be short and highly efficient, EBIST devices are increasingly being chosen for trapping and/or reacceleration of radioactive beams. The sources can range from petite to grand, using electron beams from ~1mA to 10A or more. They often serve accelerators and beam lines in large laboratories but they can be self contained laboratories where experiments are made in situ. We will discuss the basic principles as well as applications of these sources at various facilities around the world. Some emphasis will be placed on the recently commissioned RHIC EBIS source which is now providing beams for both high energy physics at the relativistic heavy ion collider as well as the NASA space radiation laboratory at BNL.
slides icon Slides WEB01 [2.850 MB]  
WEB02 Commissioning of CARIBU EBIS Charge Breeder Sub-systems gun, ion, cathode, solenoid 165
  • S.A. Kondrashev, C. Dickerson, A. Levand, P.N. Ostroumov, R.C. Vondrasek
    ANL, Argonne, USA
  • M.A. Batazova, G.I. Kuznetsov
    BINP SB RAS, Novosibirsk, Russia
  • A.I. Pikin
    BNL, Upton, Long Island, New York, USA
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
A high-efficiency charge breeder based on an Electron Beam Ion Source (EBIS) to increase the intensity and improve the purity of accelerated neutron-rich radioactive ion beams is being developed by the ANL Physics Division. The design of the EBIS charge breeder is complete and manufacturing of the components and sub-systems is in progress. A 6-Tesla superconducting solenoid and a high-perveance electron gun were recently delivered and successfully commissioned. The current status of the ANL EBIS development and commissioning results of different EBIS sub-systems will be presented.
slides icon Slides WEB02 [1.219 MB]  
WEB03 DREEBIT EBIS/T for Applications in Accelerator Physics ion, ion-source, target, injection 170
  • M. Schmidt, A. Thorn
    DREEBIT GmbH, Dresden, Germany
  • G. Zschornack
    Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany
  Funding: Supported by the European Regional Development Fund (ERDF) and the German Federal Ministry of Economics and Technology
Electron Beam Ion Sources and Traps provide light up to heavy ions of low up to high charge states for various applications in accelerator physics such as medical particle therapy and charge breeding. Beside the well-known but quiet costly superconducting EBIS/T type systems compact and permanent magnet-operated EBIS/T from the DREEBIT Company are available, favorable for low-budget projects. Moreover, the "flagship" of the DREEBIT ion source family, the superconducting EBIS-SC features operating parameters comparable to the complex and expensive systems in the EBIS/T community.
slides icon Slides WEB03 [3.655 MB]  
poster icon Poster WEB03 [7.892 MB]  
WEB04 Electron and Ion Beam Dynamics in the CARIBU EBIS Charge Breeder ion, simulation, ion-source, acceleration 172
  • C. Dickerson, S.A. Kondrashev, B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  • A.I. Pikin
    BNL, Upton, Long Island, New York, USA
  Funding: This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
An Electron Beam Ion Source (EBIS) is being built to charge breed ion beams from the Californium Rare Isotope Breeder Upgrade (CARIBU) for acceleration in the Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Laboratory (ANL). The overall efficiency of the source and charge breeder system is important since CARIBU will produce many low intensity radioactive ion species. Simulations of the electron and ion beam dynamics have been used to determine the system’s expected performance. The details of these simulations and results will be presented.
slides icon Slides WEB04 [1.362 MB]  
WEB05 ECRIS Latest Developments ion, ECRIS, ion-source, plasma 173
  • L. Celona, G. Castro, S. Gammino, D. Mascali
    INFN/LNS, Catania, Italy
  • G. Ciavola
    CNAO Foundation, Milan, Italy
  The production of intense beams of highly charged ions (HCI) is one of the most relevant challenge for the future accelerator facilities. Electron Cyclotron Resonance Ion Sources (ECRIS) are nowadays the most powerful devices able to feed accelerators with HCI in a reliable and efficient way. The reliability of frontier solutions for magnets and the increased costs for microwave generators make scaling to larger frequency not viable. Any further improvement of ECRIS output currents and average charge state requires a deep understanding of electron and ion dynamics in the plasma. In the past 20 years different teams have been working in the forefront of ion source developments with both experimental and theoretical activities, proposing different solutions to improve the production rate. The paper will discuss the most recent technological developments in the field, worldwide, together with the modeling issues of non-classical evidences like sensitivity of Electron Energy Distribution Function to the magnetic field detuning, influence of plasma turbulences on electron heating and ion confinement, coupling between electron and ion dynamics and relative impact on the formed ion beam.  
THB01 New Developments in Low-Z Gas Stripper Sstem at RIKEN Radioactive Isotope Beam Factory (RIBF) ion, acceleration, target, cyclotron 199
  • H. Okuno, N. Fukunishi, H. Hasebe, H. Imao, O. Kamigaito, M. Kase, H. Kuboki
    RIKEN Nishina Center, Wako, Japan
  Electron stripping process from heavy ion in material is a useful tool in accelerator complex to give higher charge state of the ion, allowing its effective acceleration. This process is competed with electron capture process and reach to the equilibrium charge state. Carbon foils is convenient for charge stripper but have short lifetime due to thermal stress and sputtering in the case of high power beam of heavy ion such as uranium. Gas is basically free from lifetime but gives lower charge state due to absent of density effect. Therefore, charge stripper especially for uranium beams at 10-20 MeV/u could be a bottle-neck problem in high power heavy ion facility such as RIBF, FRIB and FAIR. A charge stripper using low-Z gas (He or H2) is an important candidate to solve the problem because the high equilibrium mean charge states for the low-Z gas stripper are expected due to the suppression of the electron capture process. This presenation will describe the results for the develeopments and tests of He gas stripper for uranium beams at 11 MeV/u.  
slides icon Slides THB01 [7.108 MB]  
THB05 The HITRAP Decelerator and Beam Instrumentation ion, rfq, diagnostics, instrumentation 217
  • F. Herfurth, Z. Andjelkovic, W.A. Barth, K. Brantjes, G. Clemente, L.A. Dahl, S. Fedotova, P. Gerhard, M. Kaiser, O.K. Kester, H.J. Kluge, C. Kozhuharov, M.T. Maier, D. Neidherr, W. Quint, A. Reiter, T. Stöhlker, G. Vorobjev, S.G. Yaramyshev
    GSI, Darmstadt, Germany
  • U. Ratzinger, A. Schempp
    IAP, Frankfurt am Main, Germany
  A linear decelerator is being commissioned for heavy, highly-charged ions (HCI) at GSI in Darmstadt/Germany. HCI with only one or few electrons are interesting systems for many different experiments as for instance precision tests of the theory of quantum electrodynamics (QED). In order to transform heavy HCI produced at 400 MeV/u to stored and cooled HCI at low energy the linear decelerator facility HITRAP has been setup behind the experimental storage ring (ESR). The ions are decelerated in the ESR from 400 to 4 MeV/u, cooled and extracted. The ions are then matched to an IH-structure using a double drift buncher, decelerated from 4 to 0.5 MeV/u in the IH, and then down to 6 keV/u in a 4-rod RFQ. To detect and analyze the weak and sparse ion bunches a new type of energy analyzing detector has been developed along with improvements to other “standard” beam instrumentation. One million highly charged ions have been decelerated with the IH from 400 MeV/u to about 0.5 MeV/u per cycle. The RFQ has shown in off-line tests to decelerate ions, however, the measured acceptance does not fit the ion beam from the IH. This requires a refined design, which is underway.  
slides icon Slides THB05 [2.925 MB]