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Eunsan Kim - One of the best experts on this subject based on the ideXlab platform.

  • Beam dynamics and error study of the medium Energy Beam transport line in the Korea Heavy-Ion Medical Accelerator
    Journal of the Korean Physical Society, 2016
    Co-Authors: Chanmi Kim, Eunsan Kim, Garam Hahn
    Abstract:

    The Korea Heavy Ion Medical Accelerator consists of an injector and a synchrotron for an ion medical accelerator that is the first carbon-ion therapy system in Korea. The medium Energy Beam transport(MEBT) line connects the interdigital H-mode drift tube linac and the synchrotron. We investigated the Beam conditions after the charge stripper by using the LISE++ and the SRIM codes. The Beam was stripped from C^4+ into C^6+ by using the charge stripper. We investigated the performance of a de-buncher in optimizing the Energy spread and the Beam distribution in z-dW/W (direction of Beam progress-Beam and Energy) phase. We obtained the results of the tracking simulation and the error analysis by using the TRACK code. Possible misalignments and rotations of the magnets were considered in the simulations. States of the Beam were examined when errors occurred in the magnets by the applying analytic fringe field model in TRACK code. The condition for the Beam orbit was optimized by using correctors and profile monitors to correct the orbit. In this paper, we focus on the Beam dynamics and the error studies dedicated to the MEBT Beam line and show the optimized Beam parameters for the MEBT.

  • development of a low Energy Beam transport system at kbsi heavy ion accelerator
    Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2015
    Co-Authors: Jung Bae Bahng, Seyong Choi, Byoungseob Lee, Jung Woo Ok, Janghee Yoon, Misook Won, Jin Yong Park, Y. Sato, Eunsan Kim
    Abstract:

    Abstract The Korea Basic Science Institute has developed a heavy ion accelerator for fast neutron radiography [1] . To meet the requirements for fast neutron generation, we have developed an accelerator system that consists of an electron cyclotron resonance ion source (ECR-IS), low-Energy Beam transport (LEBT) system, radio-frequency quadrupole (RFQ), medium-Energy Beam transport system, and drift tube linac. In this paper, we present the development of the LEBT system as a part of the heavy ion accelerator system, which operates from the ECR-IS to the RFQ entrance.

  • Design study of low-Energy Beam transport for multi-charge Beams at RAON
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2015
    Co-Authors: Jung Bae Bahng, Ji Qiang, Eunsan Kim
    Abstract:

    Abstract The Rare isotope Accelerator Of Newness (RAON) at the Rare Isotope Science Project (RISP) is being designed to simultaneously accelerate Beams with multiple charge states. It includes a driver superconducting (SC) linac for producing 200 MeV/u and 400 kW continuous wave (CW) heavy ion Beams from protons to uranium. The RAON consists of a few electron cyclotron resonance ion sources, a low-Energy Beam transport (LEBT) system, a CW 81.25 MHz, 500 keV/u radio frequency quadrupole (RFQ) accelerator, a medium-Energy Beam transport system, the SC linac, and a charge-stripper system. The LEBT system for the RISP accelerator facility consists of a high-voltage platform, two 90° dipoles, a multi-harmonic buncher (MHB), solenoids, electrostatic quadrupoles, a velocity equalizer, and a diagnostic system. The ECR ion sources are located on a high-voltage platform to reach an initial Beam Energy of 10 keV/u. After extraction, the ion Beam is transported through the LEBT system to the RFQ accelerator. The generated charge states are selected by an achromatic bending system and then bunched by the MHB in the LEBT system. The MHB is used to achieve a small longitudinal emittance in the RFQ by generating a sawtooth wave with three harmonics. In this paper, we present the results and issues of the Beam dynamics of the LEBT system.

  • Design of medium Energy Beam transport for the rare isotope science project
    Journal of the Korean Physical Society, 2013
    Co-Authors: Hye-jin Kim, Eunsan Kim, B. H. Choi, Ji-gwang Hwang
    Abstract:

    The front-end system of rare isotope accelerator of newness (RAON) heavy-ion accelerator, which consists of an electron cyclotron resonance (ECR) ion source, a low Energy Beam transport (LEBT), a radio frequency quadrupole (RFQ) and a medium Energy Beam transport(MEBT), is now in the technical design phase to optimize and improve the optics. Especially, MEBT system is installed between the RFQ linac and the superconducting linac (SCL). It requires careful matching of the optical parameters in transverse plane and removes the unaccelerated ion Beams from the RFQ linac. It also includes the Beam diagnostic devices to measure the Beam quality at the exit of the RFQ linac. Quadrupole magnets and normal-conducting re-bunchers are used to minimize the growths of the transverse and the longitudinal emittances. To remove the unaccelerated ion Beams, we choose a normal-conducting quarter wave resonator (QWR) and designed it by using the Micro Wave Studio (MWS) code. The re-buncher has a maximum electric field of 2.95 MV/m on the cavity surface with an electric field of 1 MV/m on the Beam axis, a geometrical beta factor of 0.025 and an effective length of 22 cm. Beam simulations shows that the Beams from upstream of the LEBT and the RFQ can be transported by the MEBT without any increases in the Beam emittances.

Hyunchang Jin - One of the best experts on this subject based on the ideXlab platform.

  • Designing of the low Energy Beam lines with achromatic condition in the RAON accelerator
    Journal of the Korean Physical Society, 2017
    Co-Authors: Hyunchang Jin, Jiho Jang, Dong-o Jeon
    Abstract:

    The RAON accelerator has been built to create and accelerate stable heavy-ion Beams and rare isotope Beams. The stable heavy-ion Beams are generated by the superconducting electron cyclotron resonance ion source and accelerated by the low Energy superconducting linac SCL1. The Beams accelerated by the SCL1 are re-accelerated by the high Energy superconducting linac SCL2 for the generation of rare isotope Beams by using the in-flight fragmentation system or are put to use in the low Energy experimental halls, which include the neutron science facility and the KOrea Broad acceptance Recoil spectrometer and Apparatus after having passed through the low Energy Beam lines which have long deflecting sections. At the end of each Beam line in the low Energy experimental halls, the Beams should meet the targets of the two facilities with the specific requirements satisfied. Namely, if the Beam is to be sent safely and accurately to the targets and simultaneously, satisfy the requirements, an achromatic lattice design needs to be applied in each Beam line. In this paper, we will present the lattice design of the low Energy Beam lines and describe the results of the Beam dynamics simulations. In addition, the correction of the Beam orbit, which is distorted by machine imperfections, will be discussed.

  • Beam dynamics simulations of post low Energy Beam transport section in raon heavy ion accelerator
    Review of Scientific Instruments, 2016
    Co-Authors: Hyunchang Jin, Hyojae Jang, Jiho Jang, Inseok Hong
    Abstract:

    RAON (Rare isotope Accelerator Of Newness) heavy ion accelerator of the rare isotope science project in Daejeon, Korea, has been designed to accelerate multiple-charge-state Beams to be used for various science programs. In the RAON accelerator, the rare isotope Beams which are generated by an isotope separation on-line system with a wide range of nuclei and charges will be transported through the post Low Energy Beam Transport (LEBT) section to the Radio Frequency Quadrupole (RFQ). In order to transport many kinds of rare isotope Beams stably to the RFQ, the post LEBT should be devised to satisfy the requirement of the RFQ at the end of post LEBT, simultaneously with the twiss parameters small. We will present the recent lattice design of the post LEBT in the RAON accelerator and the results of the Beam dynamics simulations from it. In addition, the error analysis and correction in the post LEBT will be also described.

  • Prototyping of Beam position monitor for medium Energy Beam transport section of RAON heavy ion accelerator
    The Review of scientific instruments, 2016
    Co-Authors: Hyojae Jang, Hyunchang Jin, Jiho Jang, Inseok Hong
    Abstract:

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The Beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for Beam acceleration. For such treatment, low Energy Beam transport, radio frequency quadrupole, and medium Energy Beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline Beam position monitor (BPM) to measure the position of ion Beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  • Lattice design and Beam dynamics studies of the high Energy Beam transport line in the RAON heavy ion accelerator
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 2015
    Co-Authors: Hyunchang Jin, Hyojae Jang, Jiho Jang, Dong-o Jeon
    Abstract:

    In RAON heavy ion accelerator, Beams generated by superconducting electron cyclotron resonance ion source (ECR-IS) or Isotope Separation On-Line (ISOL) system are accelerated by lower Energy superconducting linac and high Energy superconducting linac. The accelerated Beams are used in the high Energy experimental hall which includes bio-medical and muon-SR facilities, after passing through the high Energy Beam transport lines. At the targets of those two facilities, the stable and small Beams meeting the requirements rigorously are required in the transverse plane. Therefore the Beams must be safely sent to the targets and simultaneously satisfy the two requirements, the achromatic condition and the mid-plane symmetric condition, of the targets. For this reason, the lattice design of the high Energy Beam transport lines in which the long deflecting sections are included is considered as a significant issue in the RAON accelerator. In this paper, we will describe the calculated Beam optics satisfying the conditions and present the result of particle tracking simulations with the designed lattice of the high Energy Beam transport lines in the RAON accelerator. Also, the orbit distortion caused by the machine imperfections and the orbit correction with correctors will be discussed.

Didier Uriot - One of the best experts on this subject based on the ideXlab platform.

  • Space Charge Compensation in Low Energy Beam Lines
    2016
    Co-Authors: Frédéric Gérardin, Maud Baylac, Dominique Bondoux, Frédéric Bouly, Antoine Chancé, Nicolas Chauvin, Olivier Napoly, Nicolas Pichoff, Didier Uriot
    Abstract:

    The dynamics of a high intensity Beam with low Energy is governed by its space-charge forces which may be responsible of emittance growth and halo formation due to their non-linearity. In a low Energy Beam transport (LEBT) line of a linear accelerator, the propagation of a charged Beam with low Energy causes the production of secondary particles created by the interaction between the Beam and the background gas present in the accelerator tube. This phenomenon called space-charge compensation is difficult to characterize analitically. In order to obtain some quantitative to characterize the space-charge compensation (or neutralization), numerical simulations using a 3D PIC code have been implemented.

  • Space Charge Compensation in Low Energy Beam Lines
    2016
    Co-Authors: Frédéric Gérardin, Maud Baylac, Dominique Bondoux, Frédéric Bouly, Antoine Chancé, Nicolas Chauvin, Olivier Napoly, Nicolas Pichoff, Didier Uriot
    Abstract:

    The dynamics of a high intensity Beam with low Energy is governed by its space-charge forces which may be responsible of emittance growth and halo formation due to their non-linearity. In a low Energy Beam transport (LEBT) line of a linear accelerator, the propagation of a charged Beam with low Energy causes the production of secondary particles created by the interaction between the Beam and the background gas present in the accelerator tube. This phenomenon called space-charge compensation is difficult to characterize analitically. In order to obtain some quantitative values to characterize the space-charge compensation (or neutralization), numerical simulations using a 3D PIC code have been implemented.

  • transport of intense ion Beams and space charge compensation issues in low Energy Beam lines invited
    Review of Scientific Instruments, 2012
    Co-Authors: Nicolas Chauvin, O Delferriere, Romuald Duperrier, R Gobin, P A P Nghiem, Didier Uriot
    Abstract:

    Over the last few years, the interest of the international scientific community for high power accelerators in the megawatt range has been increasing. For such machines, the ion source has to deliver a Beam intensity that ranges from several tens up to a hundred of mA. One of the major challenges is to extract and transport the Beam while minimizing the emittance growth and optimizing its injection into the radio frequency quadrupole. Consequently, it is crucial to perform precise simulations and cautious design of the low Energy Beam transport (LEBT) line. In particular, the Beam dynamics calculations have to take into account not only the space charge effects but also the space charge compensation of the Beam induced by ionization of the residual gas. The physical phenomena occurring in a high intensity LEBT and their possible effects on the Beam are presented, with a particular emphasis on space charge compensation. Then, Beam transport issues in different kind of LEBTs are briefly reviewed. The SOLMAX...

C. Wiesner - One of the best experts on this subject based on the ideXlab platform.

  • pip ii injector test s low Energy Beam transport commissioning and selected measurements
    arXiv: Accelerator Physics, 2017
    Co-Authors: A Shemyakin, M. Alvarez, Richard Andrews, B. Hanna, V. Scarpine, A. Chen, J P Carneiro, R Darcy, L Prost, C. Wiesner
    Abstract:

    The PI-Test test accelerator is under construction at Fermilab. Its ion source and Low Energy Beam Transport (LEBT) in its initial (straight) configuration have been commissioned to full specification parameters. This paper introduces the LEBT design and summarizes the outcome of the commissioning activities.

  • PIP-II Injector Test's Low Energy Beam Transport: Commissioning and Selected Measurements
    2017
    Co-Authors: Alexander Shemyakin, Lionel Prost, M. Alvarez, Richard Andrews, Jean-paul Carneiro, B. Hanna, V. Scarpine, R. D'arcy, A. Chen, C. Wiesner
    Abstract:

    The PIP2IT test accelerator is under construction at Fermilab. Its ion source and Low Energy Beam Transport (LEBT) in its initial (straight) configuration have been commissioned to full specification parameters. This paper introduces the LEBT design and summarizes the outcome of the commissioning activities.

  • Pxie low Energy Beam transport commissioning
    arXiv: Accelerator Physics, 2015
    Co-Authors: Lionel Prost, M. Alvarez, Richard Andrews, Jean-paul Carneiro, B. Hanna, V. Scarpine, Alexander Shemyakin, R. D'arcy, C. Wiesner
    Abstract:

    The Proton Improvement Plan II (PIP-II) at Fermilab is a program of upgrades to the injection complex. At its core is the design and construction of a CW-compatible, pulsed H- superconducting RF linac. To validate the concept of the front-end of such machine, a test accelerator (a.k.a. PXIE) is under construction. It includes a 10 mA DC, 30 KeV H- ion source, a 2 m-long Low Energy Beam Transport (LEBT), a 2.1 MeV CW RFQ, followed by a Medium Energy Beam Transport (MEBT) that feeds the first of 2 cryomodules increasing the Beam Energy to ~25 MeV, and a High Energy Beam Transport section (HEBT) that takes the Beam to a dump. The ion source and LEBT, which includes 3 solenoids, several clearing electrodes/collimators and a chopping system, have been built, installed, and commissioned to full specification parameters. This report presents the outcome of our commissioning activities, including phase-space measurements at the end of the Beam line under various neutralization schemes obtained by changing the electrodes' biases and chopper parameters.

R. Keller - One of the best experts on this subject based on the ideXlab platform.

  • simulation of the ion source extraction and low Energy Beam transport systems for the spallation neutron source
    Review of Scientific Instruments, 2002
    Co-Authors: R F Welton, M P Stockli, R. Keller, J E Boers, R Rauniyar, J Staples, R. Thomae
    Abstract:

    The ion source for the Spallation Neutron Source is a radio-frequency (rf) multi-cusp, volume-type H− source that is coupled to a rf quadrupole accelerator through a low Energy Beam transport (LEBT) system consisting of five electrostatic elements. To gain a deeper understanding of the operation of this system and to continue to refine the design, we have performed ion extraction and transport simulations using the computer code PBGUNS. A comparison is presented between simulation and the measured phase space of the Beam for various values of LEBT electrode potentials. Both the emittance magnitude and orientation in phase space were found to be in reasonable agreement with measurement. A design study is also presented where the angle of the source outlet electrode has been optimized with the aid of PBGUNS simulations, resulting in a substantial reduction of the emittance.

  • Ion-source and low-Energy Beam-transport issues with the front-end systems for the spallation neutron source
    Review of Scientific Instruments, 2002
    Co-Authors: R. Keller, D.w. Cheng, R. Digennaro, R. A. Gough, J. Greer, Ka-ngo Leung, A. Ratti, Jani Reijonen, R. Thomae, Thomas Schenkel
    Abstract:

    The front-end systems (FES) of the spallation neutron source project are being built by Berkeley Lab and will deliver a pulsed 40 mA H− ion Beam at 2.5 MeV Energy to the subsequent drift-tube linac. The FES accelerator components comprise a rf driven, volume-production, cesium-enhanced, multicusp ion source; an electrostatic low-Energy Beam transport (LEBT) that includes provisions for transverse focusing, steering, and Beam chopping; a radio-frequency quadrupole accelerator; and a medium-Energy Beam transport line. The challenges for ion source and LEBT design are the generation of a plasma suitable for creating the required high H− ion density, lifetime of the rf antenna at 6% duty factor, removal of the parasitic electron population from the extracted negative ions, and emittance conservation. The article discusses these issues in detail and highlights key experimental results obtained so far.

  • Ion-source and low-Energy Beam-transport issues for H/sup -/ accelerators
    Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366), 1
    Co-Authors: R. Keller
    Abstract:

    H/sup -/ ions are being used in high-Energy accelerators and spallation neutron-sources because of the efficiency with which they can be converted into protons at high Energy, a mechanism utilized in schemes that provide injection into a ring by means of charge. This paper discusses new trends and recent developments in the field of H/sup -/ plasma generators, extraction systems, and low-Energy Beam-transport (LEBT) systems, with emphasis on low-emittance systems delivering Beams in the 50-mA range.