24th International Workshop on ECR Ion Sources (ECRIS'20)

America/Detroit
Guillaume Machicoane (FRIB)
    • 08:30 09:00
      Opening Session 30m
    • 09:00 09:05
      Status Report and New Development 5m
    • 09:05 09:30
      FECR Ion Source Development and Challenges 25m

      FECR or the First 4th generation ECR ion source is
      under development at Institute of Modern Physics
      (IMP) since 2015. This ion source is aiming to extract
      intense highly charged heavy ion beams in the order
      of emA from the dense plasma heated with 45 GHz
      microwave power. To provide effective magnetic
      confinement to the 45 GHz ECR plasma, a state of
      the art Nb3Sn magnet with min-B configuration is a
      straightforward technical path. As there is no much
      precedent references, it has to be designed,
      prototyped at IMP through in-house development.
      Meanwhile, other physics and technical challenges to
      a 4th generation ECR ion source are also tackled at
      IMP to find feasible solutions. This paper will give a
      brief review of the critical issues in the development
      of FECR ion source. A detailed report on the status of
      FECR prototype magnet development will be
      presented.

      Speaker: Dr Liangting Sun (Institute of Modern Physics, CAS)
    • 09:30 09:55
      LECR5 Development and Status Report 25m

      LECR5 (Lanzhou Electron Cyclotron Resonance ion
      source No. 5) is an 18 GHz room temperature ECR
      ion source featuring Ø80 mm ID (Internal Diameter)
      plasma chamber and high magnetic fields. It has
      been successfully constructed at IMP recently and has
      been fully commissioned to meet the requirements of
      SESRI (Space Environment Simulation and Research
      Infrastructure) project. According to the test results,
      LECR5 can meet the requirements of SESRI with
      sufficient beam intensities within the required the
      transverse emittances. As LECR5 is designed to be
      optimal for the operation at 18 GHz, we have
      managed to explore the source performance at 18
      GHz with a maximum microwave power around 2 kW.
      Recent source test indicates, LECR5 can produce not
      only high intensity ion beams such as 2.12 emA O6+,
      121 e¿A of Ar14+, 73 e¿A of Kr23+, 145 e¿A of
      Xe27+, but also very high charge state ion beams
      such as 22 e¿A of Bi41+. This paper will present the
      recent progress with LECR5, especially the intense
      ion beam production and the beam quality
      investigation.

      Speaker: Cheng Qian (IMP/CAS, Lanzhou; University of Chinese Academy of Sciences, Beijing))
    • 09:55 10:20
      Status of the AISHa Ion Source at INFN-LNS 25m

      The AISHa ion source is an Electron Cyclotron
      Resonance Ion Source designed to generate high
      brightness multiply charged ion beams with high
      reliability, easy operations and maintenance for
      hadrontheraphy applications. The R&D performed by
      the INFN-LNS team during the 2019/2020 has
      allowed the improvement of the AISHa performances
      up to 20% for some of the extracted beams: both
      injection and extraction flanges has been improved
      and a movable electrode has been installed. The low
      energy beam transport has been equipped of an
      Emittance Measurement Unit (EMU), working through
      the beam wire scanners principle, for the
      measurement of the vertical and horizontal emittance
      of the beams of interest for hadrontherapy
      applications. Beam emittance has been characterized
      as a function of q/m and of the beam intensity to
      highlight space charge effects. If necessary, the
      beam wire scanners can be used for the
      characterization of the beam shape. The perspectives
      for further developments and plasma diagnostics will
      be also highlighted.

      Speaker: Luigi Celona (INFN-LNS)
    • 10:20 10:45
      Gismo Gasdynamic ECR Ion Source Status: Towards High-Intensity Ion Beams of Superior Quality 25m

      GISMO, a CW high-current quasi-gasdynamic ECR ion
      source, is under development at the IAP RAS. The
      quasi-gasdynamic confinement regime, featuring high
      plasma density (up to 10^14 cm^-3) and moderate
      electron temperature (~100 eV), allowed to extract
      pulsed beams of H+ and D+ ions with current of 450
      mA and RMS emittance <0.07 pi mm mrad*. It has
      been already demonstrated that major benefits of
      quasi-gasdynamic confinement, previously tested in
      pulsed mode, are scalable to the CW operational
      mode. In first experiments at GISMO facility, the ion
      beams were extracted in pulsed mode from the CW
      plasma of ECR discharge due to technical limitations
      of cooling circuits. Proton beams with current up to
      70 mA were achieved at extraction voltage of 40 kV.
      A new unique extraction system especially effective
      for the formation of high current density ion beams
      was developed and tested. Latest results of beam
      current, emittance and charge state distribution
      measurements are presented. Another possible
      application of a quasi-gasdynamic plasma might be
      the intense source of vacuum ultraviolet radiation
      (VUV). Results of VUV measurements performed at
      GISMO facility are also presented.

      Speaker: Ivan Izotov (IAP/RAS, Nizhny Novgorod)
    • 10:45 11:10
      Break 25m
    • 11:10 11:15
      Status Report and New Development II 5m
    • 11:15 11:40
      Status of the 45 GHz MARS-D Ion Source 25m

      Development of the MARS-D ECR ion source, a 45
      GHz next generation ECRIS using a NbTi MARSmagnet,
      has been continuously moving forward at
      LBNL. Recent stress analyses and other key
      components of the MARS-D ion source have been
      essentially finalized. This article presents and
      discusses the status of this new 45 GHz ECR ion
      source, such as the latest design features and the
      fabrication plan with funding available in the very
      near future.

      Speaker: Daniel Xie (LBNL, Berkeley, California)
    • 11:40 12:05
      Conceptual Design of Heavy Ion ToF-ERDA Facility Based on Permanent Magnet ECRIS and Variable Frequency RFQ Accelerator 25m

      Ion beam analysis is typically based on tandem
      accelerators and negative ions. The required 5-20
      MeV energies for heavy ion time-of-flight elastic
      recoil detection analysis (ToF-ERDA) can be
      achieved with a high charge state ion source and RFQ
      accelerator. We present a conceptual design of a ToFERDA
      facility based on a permanent magnet ECRIS
      and variable frequency RFQ accelerating 1-10 pnA of
      40Ar8+, 84Kr17+ and 129Xe24+ ions to 4-7, 10-15
      and 13-20 MeV. We present the PM ECRIS
      requirements focusing on the CUBE-ECRIS
      * with a
      quadrupole min-B field topology. Beam dynamics
      studies demonstrating good transmission of the
      heavy ion beams from the ion source to the RFQ
      entrance through the electrostatic low energy beam
      transport (LEBT) and a permanent magnet dipole are
      presented. The predicted LEBT transmissions of the
      CUBE-ECRIS (rectangular extraction slit) and a
      conventional ECRIS (circular extraction aperture) are
      compared. The conceptual design of the RFQ is
      described and the implications of the energy spread
      on the high energy beam transport are discussed. It
      is demonstrated that an energy spread below 0.2 %
      is necessary for appropriate resolution of the heavy
      ion ToF-ERDA.

      Speaker: Olli Tarvainen (UKRI-STFC-RAL-ISIS)
    • 12:05 12:30
      FRIB 28 GHz ECR Ion Source Development and Status 25m

      To satisfy ultimate performance requirements for
      heavy ions, a 28 GHz superconducting ECR ion source
      is under development at the Facility for Rare Isotope
      Beams (FRIB) in collaboration with Berkeley National
      Laboratory. The construction and testing of the
      superconducting magnet was completed at Berkeley
      and delivered to FRIB in January 2018. The magnet
      and cryostat have been assembled on the high
      voltage platform. Magnet cooldown and field mapping
      are planned by the end of 2020. The source
      commissioning shall start in early 2021. Details of the
      ion source design, current status of assembly, and
      commissioning plan will be presented in this paper.

      Speaker: Haitao Ren (FRIB, East Lansing, Michigan)
    • 12:30 13:30
      Break 1h
    • 13:30 13:35
      Plasma Investigations 5m
    • 13:35 14:00
      Imaging in X-ray Ranges to Locally Investigate the Effect of the Two- Close-Frequency Heating in ECRIS Plasmas 25m

      Plasma instabilities limit the ECR Ion Sources
      performances in terms of flux of the extracted highly
      charged ions by causing beam ripple and unstable
      operation conditions. In a 14 GHz ECRIS (Atomki,
      Debrecen), the effect on the plasma instabilities in an
      Argon plasma at Two Close Frequencies heating
      scheme (the frequency gap is smaller than 1 GHz)
      has been explored. A special multi-diagnostic setup
      [1, 2] has been designed and implemented consisting
      of detectors for the simultaneous collection of plasma
      radio-self-emission and of high spatial resolution
      X-ray images in the 500 eV - 20 keV energy domain
      (using an X-ray pin-hole camera setup). We present
      the comparison of plasma structural changes as
      observed from X-ray images in single and doublefrequency
      operations. The latter has been particularly
      correlated to the confinement and velocity
      anisotropy, also by considering results coming from
      numerical simulations.

      Speaker: Richard Racz (Atomki, Debrecen)
    • 14:00 14:25
      High Resolution X-ray Imaging as a Powerful Diagnostics Tool to Investigate ECRIS Plasma Structure and Confinement Dynamics 25m

      High resolution spatially-resolved X-ray spectroscopy, by means of a X-ray pin-hole camera setup * operating in the 0.5-20 keV energy domain, is a very powerful method for ECRIS plasma structure evaluation. We present the setup installed at a 14 GHz ECRIS (ATOMKI, Debrecen), including a multi-layered collimator enabling measurements up to several hundreds of watts of RF pumping power and the achieved spatial and energy resolution (0.5 mm and 300 eV). Results coming by a new algorithm for analyzing Integrated (multi-events detection) and Photon-Counted images (single-event detection) to perform energy-resolved investigation will be described. The analysis permits to investigate High-Dynamic-Range (HDR) and spectrally resolved images, to study the effect of the axial and radial confinement (even separately), the plasma radius, the fluxes of deconfined electrons distinguishing fluorescence lines of the materials of the plasma chamber (Ti, Ta) from plasma (Ar) fluorescence lines. This method allows a detailed characterization of warm electrons, important for ionization, and to quantitatively estimate local plasma density and spectral temperature pixel-by-pixel.

      Speaker: Eugenia Naselli (INFN/LNS, Catania University)
    • 14:25 14:50
      The Relationship Between the Diffusion of Hot Electrons, Plasma Stability, and ECR Ion Source Performance 25m

      Plasma instabilities complicate the operation of electron cyclotron resonance ion sources. In particular, quasi-periodic losses of electrons from confinement due to kinetic cyclotron instabilities hinder ion source performance. Empirical scaling laws help guide the development of sources away from the most unstable operating points but are poorly understood. Further advancement of ECR ion source technologies requires a deeper understanding of instabilities, scaling laws, and internal processes of the ion source plasma itself. We present here results of an experimental study into these instabilities and scaling laws, and measurements of hot electron diffusion (E > 10 keV) from the 18 GHz SUSI ECRIS at the NSCL. Measurements of the average argon current and the standard deviation of their variations across multiple unstable operating points are shown. These measurements are compared to measurements of electrons that diffuse axially from the plasma chamber. In doing so it will be shown how controlling the diffusion of electrons control the stability of the plasma and optimize the ion source's performance.

      Speaker: Bryan Christopher Isherwood (MSU)
    • 14:50 15:15
      Break 25m
    • 15:15 15:20
      Poster/ Short Presentation 5m
    • 15:20 15:30
      Production of 48Ca and 48Ti Ion Beams at the DC-280 Cyclotron 10m

      The heaviest known elements (up to 118Og) were
      synthesized at the U-400 cyclotron (FLNR JINR,
      Dubna) by using a beam of 48Ca ions. During the
      tests of the DC-280 cyclotron, intense beams of 48Ca
      ions were produced. For the synthesis of the
      elements 119 and heavier, intense and stable beams
      of medium-mass elements are required, such as 50Ti
      and 54Cr. Before starting the main experiments, we
      test the production of 48Ti ion beam, which is less
      expensive than 50Ti. The article describes the
      method, technique, and experimental results on the
      production of 48Ca and 48Ti ion beam at the DC-280
      cyclotron from the DECRIS-PM ion source.

      Speaker: Dmitry Pugachev
    • 15:30 15:40
      ECR Discharge in Solenoidal Magnetic Field as a Source of Dense Wide- Aperture Plasma Fluxes 10m

      Sources of dense plasma fluxes with wide aperture
      are extensively used in applied science, i.e. surface
      treatment, and as a part of neutral beam injectors.
      ECR discharge in a solenoidal magnetic field (i.e. with
      no magnetic mirrors for plasma confinement),
      sustained by a powerful radiation of modern
      gyrotrons is under consideration at IAP RAS as a
      possible alternative to widely used vacuum arc, RF
      and helicon discharges. The use of a high frequency
      radiation (37.5 GHz) allows to obtain a discharge at
      lower pressure, sustain almost fully ionized plasma
      with density more than 10^13 cm^-3, whereas the
      power on the level of several hundreds of kW allows
      one to create such a plasma in considerably large
      volume. In the present work fluxes of hydrogen
      plasma with the equivalent current density of 750
      mA/cm2 and the total current of 5 A were obtained. A
      multi-aperture multi-electrode extraction system
      design capable of forming the non-divergent ion
      beam was developed with the use of IBSimu code.

      Speaker: Ivan Izotov (IAP/RAS, Nizhny Novgorod)
    • 15:40 15:50
      Stable and Intense 48Ca Ion Beam Production With a Microwave Shielded Oven and an Optical Spectrometer as Diagnostic Tool 10m

      The CAPRICE ECRIS installed at the High Charge
      Injector (HLI) of GSI produces highly charged ion
      beams from gaseous and metallic elements. A high
      demand of metal ions comes from the nuclear
      physics, material re-search, and Super Heavy
      Element group (SHE), and the most requested
      element, besides 50Ti, is 48Ca. When this chemical
      reactive material is deposited inside the plasma
      chamber at internal components the stability can be
      com-promised. Furthermore, it is difficult to find a
      working point to guarantee a long-term stability as
      the oven re-sponse time and the reaction of the
      ECRIS are relatively slow. The monitoring by using an
      Optical Emission Spectrometer (OES) facilitates
      immediate reactions when-ever plasma instabilities
      occur. For this reason, a real-time diagnostic system
      based on an OES has been in-stalled at the ECRIS at
      HLI for routine operation during the beam-time 2020.
      The measured spectra revealed a parasitic oven
      heating by coupled microwaves often com-promising
      the ion source performance. Therefore, a tung-sten
      grid has been installed to shield the oven orifice from
      the coupled microwaves. The results in terms of 48Ca
      beam intensity and stability are reported here.

      Speaker: Fabio Maimone (GSI, Darmstadt)
    • 15:50 16:00
      New Metallic Stable Ion Beams for GANIL 10m

      GANIL has been producing many stable beams for
      nearly 40 years. Constant progress has been made in
      terms of intensity, stability and reliability. The
      intensity for some stable metallic beams now exceeds
      or approaches the pμA level at an energy up to 95
      MeV/u: 1.14 pμA for 36S (65% enriched) at 77
      MeV/u, 0.35 pμA for 58Ni (63%) at 74 MeV/u. The
      presentation highlights recent results obtained for
      28Si, 184W and 130Te using the GANIL s LCO (Large Capacity Oven) on the ECR4 ion source. To produce the tungsten beam, two injection methods were compared. For the first one, we evaporated some tungsten trioxide (WO3) with GANILs LCO.
      For the second one, the injection in the plasma
      chamber was made by using MIVOC (Metallic Ions
      from VOlatile compounds) with a tungsten
      hexacarbonyl (W(CO)6) compound. It was the first
      time that we used metal carbonyl compounds and the
      result is promising. All the tests have been qualified
      to obtain the level of intensity and beam stability.
      Theses good results led us to propose them for
      Physics experiments.

      Speaker: Frederic Lemagnen (GANIL, Caen)
    • 16:00 16:10
      A New Resistive High Temperature Oven for Metallic Beams Production 10m

      For the Super Separator Spectrometer (S3) [1]
      currently under construction on Spiral 2 facility,
      metallic beams of high intensities must be delivered
      to impinge a target aiming to produce rare
      radioactive isotopes for fundamental nuclear studies.
      First requested beams are 58Ni, 48Ca, 50Cr, 50Ti or
      50V with an intensity about 1,2.1013 pps. The
      metallic ion beams will be produced by the Phoenix
      V3 ECR ion source combined with a resistive oven
      newly designed to cope with the beam specifications.
      The evaporation of low vapor pressure metallic
      elements (Ti, V...) requires temperature within a
      range of 1900°C to 2000°C. A new design of a
      resistive oven has been developed for this purpose.
      The oven reached 2000°C in a test vacuum chamber
      during 8 days. It has worked out in the Electron
      Cyclotron Resonance Ion Source ECR4 at GANIL for
      Titanium beam production. Further tests using this
      ion source are under preparation for Ti and V beam
      production. Flux and angular distribution of atoms
      released by the oven are going to be measured offline
      for optimizing crucibles geometries. Finally, the
      oven will be integrated into the Phoenix V3 ECRIS for
      Ti and V production.

      Speaker: Olivier Bajeat (GANIL, Caen)
    • 16:10 16:20
      Microcontrollers as Gate and Delay Generators for Time Resolved Measurements 10m

      The diffusion of electrons from ECRIS plasmas results
      in the emission of bremsstrahlung distributions from
      the plasma chamber. ECRIS bremsstrahlung
      measurements that are both time- and energyresolved
      are often challenging to perform due to the
      10's; 100's ms timescale that the plasma evolves
      over. However, the advancement of low-cost
      microcontrollers over the last decade makes timing
      and gating photon spectrometers easier. We present
      a proof of principle measurement which uses an
      Arduino microcontroller as a gate-and-delay
      generator for a High Purity Germanium (HPGe)
      detector. An example plot of the time-resolved
      bremsstrahlung spectrum, triggered by beam current
      variation induced by kinetic instabilities, is shown.

      Speaker: Bryan Christopher Isherwood (MSU)
    • 16:20 17:00
      Open Discussion 40m
    • 17:00 17:01
      Adjourn 1m
    • 08:50 09:00
      Announcements 10m
    • 09:00 09:05
      Plasma Physics and Techniques 5m
    • 09:05 09:30
      Plasma Parameters at Upper/down Stream Region Near Ecr Zone and Optimizing Microwave-Launching on ECRIS 25m

      We have investigated how to produce multicharged
      ions efficiently. Recently, we have focused on waves
      propagations in plasma and conducted the Upperhybrid
      Resonance (UHR) experiments. [1] We have
      also conducted experiments heating by the coaxial
      semi-dipole antenna to enhance the right-hand
      polarization wave, which contributes to ECR. [2]
      Multicharged ion beams have been improved using
      various means, e.g., the increase of the magnetic
      field and the microwave frequency, the DC biased
      plate-tuner, mixing low z gases, and the multiplex
      frequencies heating. However, the microwave
      launching position has been empirically determined
      on conventional ECRIS's. There is still some room for
      improvement with the respect to more efficient
      excitation of the wave propagation. In this research,
      we estimate the wave propagation near the ECR
      zone, and in the opposite peripheral region beyond it.
      We measure plasma parameters in those regions by
      two Langmuir probes inserted into each location at
      the same time. In near future, we optimize the
      microwave-launching in the case of the fundamental
      frequency for ECR and the second frequency for UHR
      in order to enhance their incidence to the vacuum
      chamber.

      Speaker: Wataru Kubo (Osaka University, Osaka)
    • 09:30 09:55
      Tentative Solution to Plasma Chamber Cooling for High Power ECR Ion Source Operation 25m

      High charge state electron cyclotron resonance ion
      source (ECRIS) is characterized by a so-called min-B
      magnetic field configuration, which provokes the
      localized plasma over-heating to plasma chamber
      especially for the 3rd generation ECRISs at high
      power operation condition. With the increase of rf
      power, more plasma energy will be dumped to tiny
      areas and result in a very high localized power
      density, which is estimated to be up to 1 kW/cm2.
      Few existing ECR plasma chamber cooling designs
      can withstand such high heat fluxes. In this paper,
      we report a new plasma chamber cooling design with
      so-called Micro-channel cooling technology, which can
      not only realize efficient heat transfer, but also
      retains a small radial thickness that is beneficial for
      the radial magnetic field. In order to evaluate the
      performance of the cooling structure with microchannel
      design, experimental cooling loop for high
      heat flux has been designed and built at IMP. Initial
      experiments demonstrate that optimized
      configuration can achieve high heat flux cooling in the
      range of 1 kW/cm2 and beyond. Based on these
      results, a plasma chamber with micro-channel design
      for SECRAL has been designed and tested.

      Speaker: Junwei Guo (IMP/CAS, Lanzhou)
    • 09:55 10:20
      Development of HTO with Inductive Technology for Uranium Beam Production 25m

      A High-Temperature Oven (HTO) with inductive
      heating technology has been developed successfully
      in 2019 at Institute of Modern Physics. This oven
      features durable operation temperature of >2000℃
      inside the tantalum susceptor. By careful design the
      oven structure, material compatibility and thermal
      stress issues at high temperature has been
      successfully handled, which enables the production of

      400 eμA U33+ with SECRAL-II*. With necessary
      refinement, this type of oven could also be available
      with room temperature ECR ion sources, like LECR4
      and LECR5. Some improvements in structure have
      been proposed in this year. The design and testing
      results will be presented in this contribution.

      Speaker: Wang Lu (IMP/CAS, Lanzhou)
    • 10:20 10:45
      Influences of Magnetic Field Parameters to ECRIS Plasma Characteristics 25m

      To investigate the hot electron population and the appearance of kinetic instabilities in ECRIS plasma, the axially emitted bremsstrahlung spectra and microwave bursts emitted from ECRIS plasma were synchronously measured on SECRAL-II ion source with various magnetic field configurations. The experimental results show that when Bmin/Becr is less than ~0.8, the spectral temperature Ts increases linearly with the Bmin/Becr-ratio when the injection, extraction and radial mirror fields are kept constant. Above this threshold Ts saturates and the electron cyclotron instability appears simultaneously. This study has also demonstrated that Ts decreases linearly with the increase of the average gradient over the ECR surface when the on-axis gradient and hexapole field strengths are constant. In addition, it is found that Ts decreases with the increase of the gradient at the resonance zone at relatively low mirror ratio and is insensitive to the gradient at high mirror ratio when Bmin is constant. Compared to a recent study taken on a fully superconducting ECRIS, this study shows different results discussing the mechanisms behind the correlation of magnetic field parameters to Ts.

      Speaker: Jibo Li (IMP/CAS)
    • 10:45 11:10
      Break 25m
    • 11:10 11:15
      Plasma Physics and Techniques II 5m
    • 11:15 11:40
      A Theoretical Model of High-Bmin Instabilities and Experimental Tests of Its Predictions 25m

      It is well known that ECR ion sources exhibit
      instabilities when the source's minimum magnetic
      field is approximately 80% of the resonant field or
      greater, but the reasons for this instability have yet
      to be satisfactorily explained. In this paper we
      present a simple theoretical model that has the highminimum-
      B instability as a consequence. We show
      that this model predicts modes of operation with
      high-minimum B that avoid that instability (including
      multiple-frequency heating), and present results from
      experimental tests of some of these predicted stable
      modes.

      Speaker: Damon Todd (LBNL, Berkeley, California)
    • 11:40 12:05
      Experimental Evidence of Trapped Waves in a Simple Mirror Magnetic-Trap 25m

      This work presents the first experimental
      characterization of cavity modes trapped within a
      plasma column in an axis-symmetric magnetic trap.
      Trapped wave has been characterized by means of a
      movable antenna as a function of the B_{min}/B_
      {ECR} ratio and plasma parameters. The study
      demonstrates that E.M waves can be trapped
      between two R-cutoff layers, in proximity of the B
      minimum position. Results suggest that the trapped
      waves consist of Whistler waves, propagating
      perpendicularly to the magnetic field and storing
      large part of the E.M power introduced in the plasma
      chamber. If R-cut-off is removed by increasing the
      density, trapped waves are not detected anymore. A
      typical Electron Energy Distribution Function
      composed by two different electron populations is
      measured in the layer where trapped waves are
      revealed, suggesting that additional heating is
      occurring. The existence of trapped waves in a
      plasma column was already foreseen by several
      studies concerning the development of kinetic
      instability in plasmas and this experimental
      characterization allows to shed more light on nonlinear
      plasma coupling and to the generation of
      supra-thermal electrons in ECRIS plasmas.

      Speaker: Giuseppe Castro (INFN/LNS, Catania)
    • 12:05 12:30
      Simulation and Experimental Investigation of an Ion Source Metallic Oven 25m

      Oven are widely used to produce metallic ion beams
      in ECRIS. A calcium oven dedicated to metal
      evaporation up to 650°C has been investigated by
      simulation and experience. The differential atom
      emittance has been measured and is well reproduced
      by the results of a Monte-Carlo simulation code. The
      absolute atom flux was measured as a function of the
      oven temperature and compared with theoretical
      predictions. A quite good agreement is obtained with
      theory and new values of Antoine's coefficient for
      calcium are proposed. The simulation is used to
      investigate the probability of on flight atom ionization
      by the plasma as a function of the oven distance to
      the ECR zone. With the PHOENIX V3 geometry, when
      the oven is placed in the injection biased disk plane,
      the ionization efficiency is 14%. This value in quite
      good agreement with experiment. Theoretical
      efficiency up to 57% is reachable when the oven
      distance is reduced to 1 cm to the ECR zone.

      Speaker: Thomas Thuillier (LPSC, Grenoble Cedex)
    • 12:30 13:30
      Break 1h
    • 13:30 13:35
      Modelisation, Simulation 5m
    • 13:35 14:00
      Progress in Self-Consistent Modeling of Time- and Space-Dependent Phenomena in Ecris Plasma 25m

      Resonant interaction with the microwave radiation in
      ECRIS plasma leads to a strongly anisotropic electron
      energy distribution function (EEDF), given as a
      combination of two to three electron populations,
      with the possibility to trigger kinetic instabilities. At
      the INFN, further efforts have been paid to improve
      and update self-consistent 3D numerical codes for
      plasma electrons kinetics. Progresses have opened
      several perspectives. It is now possible to derive
      space-resolved EEDF, and compute space-dependent
      energy and density maps. Also, the code has been
      updated to provide reaction rates of electromagnetic
      emissions, including X-ray fluorescence. An estimate
      of the local ion charge state distribution is potentially
      possible, and first evaluations are ongoing. Dealing
      with fast-transient mechanisms, such as
      electromagnetic emission via the electron-cyclotron
      MASER instability, the code is now updated for locally
      evaluating the EEDF anisotropy. We will present the
      collected results, which we believe to have a relevant
      impact both on the ECRIS plasma physics and on the
      INFN's PANDORA project that plans to use ECR
      plasmas for fundamental studies in Nuclear and
      AstroNuclear Physics.

      Speaker: Angelo Pidatella (INFN/LNS, Catania)
    • 14:00 14:25
      A Guiding Centre Approximation Approach for the Simulation of Electron Trajectories in ECR and Microwave Ion Sources 25m

      The Boris algorithm has become the standard for
      particle trajectory integration in a magnetic field. The
      high frequency electron cyclotron motion (GHz)
      constrains the time-step below 10 ps. A guiding
      centre approach neglects the detailed particle
      cyclotron motion, describing its trajectory through
      free motion of the orbit's centre along the field lines
      and corresponding drifts. It works on the assumption
      that the magnetic field strength varies in a much
      larger length scale than the cyclotron orbit. This
      approach is more computationally expensive per step
      than direct orbit integration, but a shorter overall
      computation time may be expected by using a larger
      time-step (~100 ps). This work presents a study on
      implementing the guiding centre approach in ECR ion
      sources. It is shown to reproduce accurately the
      trajectory drifts and confinement of electrons in a
      minimum-B field, but the use of long time-steps
      exacerbates a non-physical kinetic energy loss.
      Following, non-confined electron trajectories in a
      flatter field are analysed, as in a microwave discharge
      ion source, where this method's drawbacks are
      avoided due to a smaller magnetic field gradient and
      a shorter electron lifetime.

      Speaker: Jose Antonio Mendez (LPSC, Grenoble Cedex)
    • 14:25 14:50
      Electromagnetic Simulation of 'plasma-shaped' Plasma Chamber for Innovative ECRIS 25m

      The plasma chamber and injection system design
      play a fundamental role in ECRISs with the aim to
      obtain an optimized electromagnetic field
      configuration able to generate and sustain a plasma
      with a high energy content. In this work we present
      the numerical study and the design of an
      unconventionally-shaped cavity resonator* that
      possesses some key advantages with respect to the
      standard cylindrical cavities, usually adopted in ion
      sources setups. The cavity geometry, whose design
      has been completed on January 2020, has been
      inspired by the typical star-shaped ECR plasma,
      determined by the magnetic field structure. The
      chamber has been designed by using the commercial
      softwares CST and COMSOL, with the aim to
      maximize the on-axis electric field. Moreover, a
      radically innovative microwaves injection system,
      consisting in side-coupled slotted waveguides, has
      been implemented, allowing a better power coupling
      and a more symmetric power distribution inside the
      cavity with respect to the standard rectangular
      waveguides. This new 'plasma-shaped oriented'
      design could relevantly improve the performances of
      the ECRISs while making more compact the overall
      setup.

      Speaker: Giorgio Sebastiano Mauro (INFI/LNS, Catania)
    • 14:50 15:15
      Break 25m
    • 15:15 15:20
      Poster/ Short Presentation 5m
    • 15:20 15:30
      Characterization of 2.45 GHz ECR Ion Source Bench for Accelerator-Based 14-MeV Neutron Generator 10m

      The 2.45 GHz Electron Cyclotron Resonance Ion
      Source (ECRIS) has been indigenously developed.
      This development of ECRIS aims to provide high
      brightness, stable, and reliable D+ ion beam of 20
      mA in continuous (CW) mode operation for
      accelerator-based D-T neutron generator. The ECR
      ion source setup consists of a microwave system, a
      magnet system, a double wall water-cooled plasma
      chamber, a high voltage platform, a three-electrode
      ion extraction system, and a vacuum system. The
      ECR ion source test setup is installed and deuterium
      plasma generated. Three-electrode extraction system
      is designed and fabricated for the ion beam
      extraction. A ~10 mA deuterium ion beam is
      extracted from the ECR ion source. The paper covers
      the detailed experimental setup of ion beam
      characterization and diagnostics used for
      measurement of beam profile, beam current, and
      beam emittance measurements. It also covers the
      latest results of beam profile, and beam current
      measurement as a function of extraction voltage, gas
      flow, and acceleration voltage.

      Speaker: Sudhirsinh J Vala (Institute for Plasma Research, Bhat, Gandhinagar)
    • 15:30 15:40
      Electron Cyclotron Resonance Ion Source Related Research and Development Work at the Department of Physics, University of Jyväskylä (JYFL) 10m

      Recent research work of the JYFL ion source team
      covers multi-diagnostic studies of plasma instabilities,
      high-resolution plasma optical emission spectroscopy,
      ion current transient measurements to define the
      total life-time of a particle in the highly charged
      plasma. The JYFL team also elaborates the magnetic
      and technical design of the unconventional ion source
      named CUBE. The R&D work includes, in addition, the
      commissioning and operation of the highperformance
      18 GHz ECRIS, HIISI. The instability
      measurements have revealed new information about
      the parameters affecting the onset of the plasma
      instabilities and shown that different instability modes
      exist. The ion-beam transient studies have given
      information about the cumulative life-time of highlycharged
      ions convergent with the ion temperatures
      deduced from the Doppler broadening of emission
      lines. The CUBE prototype has a minimum-B
      quadrupole magnetic field topology, similar to ARCECRIS,
      and its all-permanent magnet structure has
      been optimized for 10 GHz frequency. The CUBE
      design will be presented along with its commissioning
      status. The status and operational experience with
      HIISI will be reported as well.

      Speaker: Miha Marttinen (University of Jyväskylä, Department of Physics)
    • 15:40 15:50
      Study on the Correlation between Energy Distribution of Electrons Lost from the Confinement and Plasma Bremsstrahlung on a min-B ECR Plasmas 10m

      The study of plasma bremsstrahlung has been used as a diagnostic tool for understanding the behavior of confined plasma in Electron Cyclotron Resonance Ion Sources (ECRIS). In order to understand the relation connecting the confined plasma and the electrons escaping the confinement, a series of measurements have been made to measure the bremsstrahlung produced in the axial and radial direction along with the Lost Electron Energy Distribution (LEED) axially on JYFL 14 GHz ECR. We present here the effect of various source parameters on the axial and radial bremsstrahlung along with the LEED on a min-B confined ECR plasma. The measured LEED has been found to show a correlation with bremsstrahlung measurement and also have observed as a potential diagnostic method for instability. The explanation for observed LEED and bremsstrahlung trends is provided.

      Speaker: Bichu Subhash Bhasi Bhaskar (LPSC, JYFL)
    • 15:50 16:00
      Ultra-High Current Density Produced by a 60 Ghz Ecr Ion Source 10m

      SEISM is a compact ECR ion source operating at 60
      GHz developed up to 2014. The prototype uses a
      magnetic cusp to confine the plasma. This simple
      magnetic geometry was chosen to allow the use of
      polyhelix coils (developed at the LNCMI, Grenoble) to
      generate a strong magnetic confinement featuring a
      closed ECR surface at 2.1 T. The plasma is sustained
      by a 300 kW microwave pulse of 1 ms duration and
      with a 2 Hz repetition rate. Previous experiments at
      LNCMI have successfully demonstrated the
      establishment of the nominal magnetic field and the
      extraction of ion beams with a current density up to
      ~ 1A/cm2. The presence of "afterglow" peaks was
      also observed, proving the existence of ion
      confinement in a cusp ECR ion source. The last run
      was prematurely stopped but the project restarted in
      2018 and new experiments are planned in 2021. A
      new transport beam line has been designed to
      improve ion beam transport towards the beam
      detectors. Short- and long-term research plans are
      presented, including numerical simulations of the
      beam transport line and future upgrades of the ion
      source with the main goal to transform the high
      current density measured into a real high intensity
      ion beam.

      Speaker: Thomas ANDRE (LPSC-CNRS)
    • 16:00 16:10
      Multi-Species Child-Langmuir Law with Application to ECR Ion Sources 10m

      We generalize the classical single-species Child-
      Langmuir Law to analyze multi-species beams from
      ECR ion sources. The formulation assumes the
      relative weight of each species in the extracted beam
      is known. We applied the results to charge state
      distribution data from Artemis- and Venus-type
      sources at the NSCL and LBNL respectively. The total
      measured beam current is close to the maximum
      current predicted by the multi-species Child Langmuir
      Law in each case, which indicates that beam
      extraction occurs around the regime of space charge
      limited flow. Prospects for application of the results
      and further studies on the topic are outlined.

      Speaker: Chun Yan Jonathan Wong
    • 16:10 16:20
      Beams with Three-Fold Rotational Symmetry: A Theoretical Study 10m

      Beams from ECR ion sources have 3-fold transverse
      rotational symmetry induced by the ECR sextupole.
      The symmetry imposes equality constraints among
      transverse beam moments, which can be derived
      using a theoretical framework we developed. Since
      the constraints are solely a consequence of the
      rotational symmetry of external fields, they hold for
      arbitrary charge state distribution and space charge
      intensity. These constraints provide a new tool to
      analyze phase space properties of ECR beams and
      their impact on low-energy transport. We prove that,
      regardless of their triangulation, beams with 3-fold
      rotational symmetry have the same rms emittance
      and Twiss parameters along any transverse direction.
      These counter-intuitive results are applied to the
      FRIB Front End to demonstrate how symmetry
      arguments challenge long-standing assumptions and
      bring clarity to the beam dynamics.

      Speaker: Chun Yan Jonathan Wong
    • 16:20 17:00
      Open Discussion 40m
    • 17:00 17:01
      Adjourn 1m
    • 08:10 08:20
      Announcements 10m
    • 08:20 08:25
      Poster/ Short Presentation 5m
    • 08:25 08:35
      Improvement of the Cryostat System Performance of 28-Ghz Electron Cyclotron Resonance Ion Source of the Biba by a Radiation Shielding 10m

      The BIBA (Busan Ion Beam Accelerator) is a compact
      linear accelerator facility using the 28 GHz ECRIS at
      the KBSI (Korea Basic Science Institute). Our goal is
      to generate high current fast neutrons using the
      heavy ion interaction with a proton target. For a
      stable operation of the superconducting magnets, the
      performance of cryostat system is very essential at
      the 28 GHz ECRIS. However, the emitted x-ray from
      inner plasma chamber contributes to increase an
      extra heat load to the cryostat system by absorbing
      the cold mass of the superconducting magnet.
      Therefore, we have measured X-ray spectra from the
      28 GHz ECR ion source and tried to improve the
      performance of the Cryostat System by a radiation
      shielding. In this paper, we will present the test
      results of X-ray emission on 28GHz KBSI ECRIS and
      improved cooling system performance.

      Speaker: Mi-Sook Won (Korea Basic Science Institute, Busan)
    • 08:35 08:45
      Precise Identification of Extracted Ion Beam Spectrum Initially Obtained in Synthesizing Iron-Endohedral Fullerenes on ECRIS 10m

      Electron cyclotron resonance ion source (ECRIS)
      plasma has been constructed for producing
      synthesized ion beams in Osaka Univ.[1,2] We hope
      that it can become a universal source capable of
      producing ions with wide range mass/charge ration
      (m/q). We have been trying to produce endohedral
      fullerenes in the ECRIS. We have conducted initial
      experiments on production of them only in the
      second stage of ECRIS. We have been using iron
      vapor source by induction heating (IH) from the
      mirror end along to the geometrical axis, and C60
      crucible from the side wall, respectively. We
      succeeded in realizing ECR plasma that fullerene and
      iron ions coexist on the single stage ECRIS, even by
      1kV extraction voltage.[3] By these experimental
      series, the typical CSD suggests that there is
      possibility of slight formation of iron fullerenes
      compounds and iron endohedral fullerenes. We are
      continuing to investigate the experimental conditions
      that maximize spectrum corresponding to iron
      endohedral fullerenes. In this paper we describe
      preliminary experimental results of synthesizing ironendohedral
      fullerene on the ECRIS.

      Speaker: Issei Owada
    • 08:45 08:55
      High Intensity Vanadium-Ion Beam Production to Search for New Super- Heavy Element with Z = 119 10m

      We have begun searching for the new super-heavy
      element (SHE) with Z=119 at RIKEN Heavy Ion
      LINAC (RILAC). To overcome the small production
      cross section of vanadium (V) beam on the curium
      target, the project requires a very powerful V beam.
      In order to optimize the beam intensity of V with the
      charge state of 13+, we have investigated the effects
      of the amount of V vapor, the power of 18- and 28-
      GHz microwaves, and the strength of the mirror field.
      While no significant effect was seen by changing the
      mirror field Bext from 1.4 T to 1.6 T, the amount of V
      vapor and the microwave power strongly affected.
      Based on the correlation between the V-vapor and
      the microwave power, we obtained a 600-euA V(13+)
      beam with the V consumption rate of 24 mg/h and
      the microwave power of 2.9 kW in order to execute
      about 1-month SHE experiment. Furthermore,
      because such strong mirror field enhances the
      transverse beam emittance, it is important to control
      the emittance with small reduction of the intensity.
      We have successfully controlled the beam emittance
      by using three pairs of slits (triplet slits) in LEBT by
      eliminating the peripheral beam components in both
      of the x-x' and y-y' phase spaces.

      Speaker: Takashi Nagatomo (RIKEN Nishina Center, Wako)
    • 08:55 09:05
      Enhancing Production of Multicharged Ions by Pulse Modulated Microwaves under Low Z Gas Mixing Operation on ECRIS 10m

      We are aiming at producing various ion beams in ECRIS. In the case of producing multicharged ion beams, we try to enhance loss channel of low Z ions by means of adding pulse modulated microwaves to conventional gas mixing method. Through these experiments, we explore the feasibility of selectively heating specific ions with pulse modulated microwaves and launching another low frequency RF waves. In gas mixing experiment, we use Helium as low Z gas for production of multicharged Ar and Xenon ion beams. These experiments are conducted by keeping the total pressure constant and changing the mixing ratio of Helium. The time scale of pulsed microwave is typically several to several hundreds of microseconds. We optimize the pulse period and duty ratio for producing multicharged ion beams. These effects are investigated to measure Charge State Distributions (CSDs). Also, we can measure the emittance using wire probe and multi slit attached to Ion Beam Irradiation System (IBIS). * We estimate the normalized emittance from this measurement to determine index of ion temperature in the ECRIS. In this paper, we mainly describe the results of these active and additive methods at the ECRIS.

      Speaker: Shuhei Harisaki (Osaka University)
    • 09:05 09:15
      Beam Profile Measurements of Decelerated Multicharged Xe Ions from ECRIS for Estimating Low Energy Damage on Satellites Components 10m

      Electron cyclotron resonance ion source (ECRIS) has
      been constructed for producing synthesized ion
      beams in Osaka Univ.,* Xe is used as fuel for ion
      propulsion engines on artificial satellites. There are
      problems of accumulated damages at irradiation and
      sputtering by low energy Xe ion from the engine. It is
      required to construct experimentally sputtering yield
      databases of ion beams in the low energy region from
      several hundred eV to 1keV, since there are not
      enough data of satellite component materials.
      Therefore, we are trying to investigate experimentally
      sputtering yield on materials by irradiating the low
      energy single species Xeq+ ion beams. However,
      there is a problem that if the low extraction voltage,
      the amount of beam currents is not enough to obtain
      ion beam flux for precise evaluation of sputtering
      yield data. Thus, we conduct to decelerate Xeq+ ion
      beams required low energy region after extracting at
      high voltage, e.g., 10kV. We measured the
      decelerated beam profile with x and y direction wire
      probes. As a result, we were able to estimate the
      dose of ion fluxes. We are going to conduct
      irradiation experiments on various materials.

      Speaker: Koichi Sato (Osaka University, Osaka)
    • 09:15 09:25
      Observation of Cyclotron Instabilities in SECRAL-II Ion Source 10m

      Cyclotron instabilities in Electron Cyclotron Resonance Ion Source (ECRIS) plasmas are related to non-linear interaction between plasma waves and energetic electrons, resulting in strong microwave emission, a burst of energetic electrons escaping the plasma, and the periodic oscillations of the extracted beam currents. Precedent investigation of cyclotron instabilities has proved that Bmin/BECR can be treated as a magnetic field threshold. Recently, experiments with SECRAL-II ion source demonstrate that Bmin/BECR is not the only knob, and other field parameters have also been found to be related to cyclotron instabilities, such as mirror ratio and radial field. Namely, the trigger of cyclotron instability is a combination of many magnetic field parameters. This paper will give the experimental setup at IMP for cyclotron instability investigations and experimental observations will be presented.

      Speaker: Lixuan Li (IMP/CAS)
    • 09:25 09:45
      Break 20m
    • 09:45 09:55
      High Intensity Ion Beam Extraction System for FECR 10m

      To meet the beam requirements of High Intensity
      heavy ion Accelerator Facility (HIAF), the Institute of
      Modern Physics is developing a Fourth generation
      ECR ion source (FECR). Targeting at the operation
      frequency of 45 GHz, FECR is expected to produce
      very high intensity highly charged heavy ion beams,
      such as 1.0 emA 238U35+, 2 emA 78Kr19+, 10 emA
      16O6+, etc. Based on the records with the 3rd
      generation ECR ion source operating at 24~28 GHz,
      the corresponding total drain current of FECR could
      reach 20 ~ 60 emA. To extract such high intensity
      multi-charged ion beams from the source with high
      beam quality and transmission efficiency,
      conventional diode or triode extraction system might
      not be suitable, and therefore a 4-electrode
      extraction system with a total extraction voltage of
      50 kV is designed to mitigate the space charge
      influences and minimize the beam emittance growth
      in the extraction region. In this paper, a 3D model of
      the FECR extraction system is built using the IBSimu
      code. The electrode angles, voltages and electrode
      spacings are optimized for different ion beam
      conditions respectively. Beam properties comparison
      of various simulation conditions are presented.

      Speaker: Zhen Shen (IMP/CAS, Lanzhou)
    • 09:55 10:05
      39Ar Enrichment System Based on a 2.45 GHz ECR Ion Source 10m

      Aimed at improving the ATTA's (Atom Trap Trace
      Analysis) dating efficiency with 39Ar radioactive
      isotope, an isotope enrichment system has been
      developed at IMP (Institute of Modern Physics) to
      increase the abundance of 39Ar in the incident
      sample gas. In this enrichment system, a 2.45 GHz
      ECR ion source was designed to ionize sample gas
      and produce isotopes beams with several mA, and
      the isotopes beam is transported and separated in
      the separation beam line, which is consisted of two
      quadrupoles and an analysis magnet. The separated
      isotopes are collected by a rotated aluminum foil
      target. According to the recent cross-checked results
      with ATTA, high enrichment factor of 39Ar isotope
      has been successfully reached. This paper will give a
      general introduction to the platform setup. The
      isotope enrichment efficiency is the critical issue for
      such a platform and will be specially discussed.

      Speaker: Zehua Jia (IMP/CAS, Lanzhou)
    • 10:05 10:15
      Conceptual Design of an Electrostatic Trap for High Intensity Pulsed Beam 10m

      Highly charged ion sources play an important role in
      the advancement of heavy ion accelerators
      worldwide. The beam requirements of highly charged
      heavy ions from new accelerators have driven the
      performance of ion sources to their limits and
      beyond. In parallel to developing new technologies to
      enhance the performance of ECR ion source, this
      paper presents a conceptual design of an ion trap
      aiming to convert a cw ion beam into a short beam
      pulse with high compression ratios. With an electron
      gun, a solenoid and a set of drift tubes, the injected
      ions will be trapped radially and axially. By
      manipulating the potential of drift tubes, ions can be
      accumulated with multiple injections and extracted at
      a fast or slow scheme. This paper presents the
      simulation and design results of this ion trap
      prototype.

      Speaker: Wei Huang (Institute of Modern Physics)
    • 10:15 10:25
      Numerical Simulations of Plasma Dynamics in ECRIS Afterglow 10m

      Plasma dynamics in the afterglow of ECRIS has been
      studied through the Particle-in-cell (PIC) simulations.
      A full 3D implicit electrostatic PIC code was
      developed to meet the needs of ECRIS simulations
      and to study the characteristics of the ECR plasma
      during the afterglow. The initial plasma parameters at
      the simulation start-up were assumed by referring to
      the experimental diagnostics of the ECRISs from IMP,
      Lanzhou. The dynamics of electrons and ions in the
      presence of the external magnetic field and at the
      absence of the microwave energy were simulated to
      study the mechanism of afterglow. Through the
      abundant diagnostics of the 3D PIC simulation, some
      ECR plasma features during afterglow including the
      plasma potential and electron energy distributions
      could be obtained and analyzed. The goal was to
      determine the important evolutions that contribute to
      the afterglow and thus to have a clearer
      understanding of ECRIS afterglow mode.

      Speaker: Li Lei (University of Electronic Science and Technology of China, Chengdu)
    • 10:25 10:35
      Production of Metal Ion Beams From ECR Ion Sources 10m

      The work describes the preparation of metal ion
      beams from ECR ion sources by the MIVOC (Metal
      Ions from Volatile Compounds) method. The method
      is based on the use of volatile metal compounds
      having high vapor pressure at room temperature: for
      example, Ni(C5H5)2, (CH3)5C5Ti(CH3)3 and several
      others. Using this method, intense beams of
      chromium, titanium, iron, and other ions were
      obtained at the U-400 FLNR JINR and DC-60
      cyclotrons (Astana branch of the INP, Alma-Ata,
      Kazakhstan Republic).

      Speaker: Andrey Bondarchenko (JINR)
    • 10:35 10:55
      Break 20m
    • 10:55 11:00
      Applications 5m
    • 11:00 11:25
      Present Status of HIMAC ECR Ion Sources 25m

      High-energy carbon-ion radiotherapy is being carried
      out at Heavy Ion Medical Accelerator in Chiba
      (HIMAC). Over 12000 cancer patients have been
      treated with carbon beams having energies of
      between 56-430 MeV/u since 1994. There are two
      injectors in the HIMAC for medical and experimental
      use. First injector consists of two ECR ion sources and
      one PIG ion source, the RFQ linac and the DTL.
      Usually, this injector suppling the carbon ion for
      cancer therapy and various ion such as H, He, Fe, Xe
      are accelerated for biological and physical
      experiment. The 10 GHz NIRS-ECR ion source
      produce the carbon ion for cancer therapy. The 18
      GHz NIRS-HEC ion source produce He to Xe ions for
      experimental use. Second injector consists of the
      compact ECR ion source with all permanent magnet,
      the RFQ linac and the APF IH-DTL. This injector
      supplies the carbon ion for experimental use.
      Additionally, we tried production of the Indium and
      the Tin ions by using the In(C5H5) and the Sn
      (i-C3H7)4 at the NIRS-HEC. Beam current of the
      115In20+ and 120Sn18+ were 90 and 15 micro A,
      respectively. Present status of ECR ion sources and
      some development will be described.

      Speaker: Masayuki Muramatsu (QST-NIRS, Chiba)
    • 11:25 11:50
      Attempt to Develop a 2.45 GHz Microwave Driven Source for Plasma Flood Gun 25m

      Plasma flood guns (PFGs) are widely used to
      neutralize wafer charge during the doping process in
      modern ion implanters. Compared with traditional dc
      arc discharge with filament and RF discharge, the
      microwave driven source that has long lifetime and
      has no metallic contamination is regarded as a
      potential choice of PFG [1]. Attempt to develop a
      large scale PFG based on 2.45 GHz microwave driven
      sources was launched at Peking University (PKU). A
      prototype one is a miniaturized 2.45 GHz permanent
      magnet electron cyclotron resonance (ECR) source to
      produce point-like electron beam. In previous
      experiments, more than 8 mA electron beam has
      been extracted with a Φ6 mm extraction hole at an
      input microwave power of 22 W with argon gas [2].
      Recently, studies are focusing on the possibility of
      producing of ribbon electron beams as PFG with
      2.45GHz microwave driven surface wave plasma
      (SWP) source. A cylindrical chamber surface wave
      plasma generator with a using cylindrical dielectric
      waveguide and a 70 mm×3 mm extraction slit was
      fabricated. The primary test results were obtained.
      More details of this PFGs will be discussed in this
      work.

      Speaker: Prof. Shixiang PENG (PKU, Beijing)
    • 11:50 12:15
      Open Discussion 25m
    • 12:15 13:15
      Break 1h
    • 13:15 13:20
      Charge Breeding 5m
    • 13:20 13:45
      Role of the 1+ Beam Optics Upstream the SPIRAL1 Charge Breeder 25m

      The SPIRAL1 charge breeder (SP1CB) is under
      operation. Radioactive ion beam (RIB) has already
      been delivered [1] to Physicist for experiments.
      Although charge breeding efficiencies demonstrated
      high performances for stable ion beams, those
      efficiencies regarding RIB are lower. The beam optics,
      prior to the injection of the 1+ ions into the SP1CB, is
      of prime importance [2] for getting such high
      efficiencies. Moreover, the intensities of the
      radioactive ion beams are so low, it is really difficult
      to tune the SP1CB. A stable beam having a close B
      is required to find out the set of optic parameters
      preceding the tuning of the RIB. Hence, it has been
      decided to focus our effort on that issue as to get
      control of the 1+ beam optics leading to high charge
      breeding efficiencies whatever the 1+ mass, energy
      and Target Ion Source System used (TISS). Being
      aware that TISS's provide ion beams with a specific
      energy spread and knowing that the acceptance
      energy of the SP1CB is rather narrow; that parameter
      must play also a role in the charge breeding
      efficiency. This contribution will show the strategy
      undertaken to overcome that problem and the results
      already obtained.

      Speaker: Laurent Maunoury (GANIL)
    • 13:45 14:10
      LNL GANIL LPSC Collaboration On The Contaminants Reduction In ECR Charge Breeders 25m

      Contaminants reduction in Electron Cyclotron
      Resonance Charge Breeders (ECRCB) is a key point
      for the future experiments foreseen at LNL and
      GANIL Isotope Separation On Line (ISOL) facilities.
      According to the mass separator resolution set
      downstream the ECRCB, the radioactive ion beam
      study can be challenged in case of low production
      rate. An ongoing collaboration between LNL, LSPC
      and GANIL laboratories aims to improve the beam
      purity, acting on all the pollutant causes.
      Comparative experiments will be done at LPSC using
      different techniques, like covering the plasma
      chamber wall with liners in several material. Different
      configurations of the ECRCB will also be tested, with
      the enhancement of the efficiency and charge
      breeding time parameters as additional objectives. A
      presentation of this program is proposed together
      with the effective upgrade of the LPSC 1+N+ test
      bench which goal was to improve the vacuum quality
      and clean all the beam line devices.

      Speaker: Julien ANGOT (Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38000 Grenoble, France)
    • 14:10 14:15
      Poster/ Short Presentation 5m
    • 14:15 14:25
      ECR3 Commissioning and Planning for C-14 Ion Beams at the Argonne Tandem Linac Accelerator System 10m

      The Electron Cyclotron Resonance Ion Source ECR3*
      has recently been commissioned at the Argonne
      Tandem Linac Accelerator System (ATLAS) at
      Argonne National Laboratory. While ECR3 can provide
      many of the stable ATLAS beams, its other intended
      purpose is the production of C-14 ion beams which
      were previously produced by a now-retired negative
      ion source. This paper will discuss the final
      installation and commissioning of the ion source as
      well as the preparations for running C-14. A stable
      C-13 ethylene gas was used as a surrogate to
      determine the expected level of N-14 contamination
      when running C-14 since they are inseparable at
      ATLAS. We were also able to confirm consumption
      rates and charge state efficiencies under different
      C-13 running conditions in order to optimize the
      upcoming C-14 beam production.

      Speaker: Robert Scott (Argonne National Laboratory)
    • 14:25 14:35
      Improvement of the Efficiency of the Triumf Charge State Booster 10m

      The Electron Cyclotron Resonance Ion Source is a
      versatile and reliable source to charge-breed rare
      isotopes in TRIUMF's Isotopes Separation and
      Acceleration (ISAC) facility. Significant research work
      has been done by different groups worldwide to
      improve the efficiency and performance of the ECRIS
      as a charge state booster. The most recent of these
      research works is the implementation of the twofrequency
      heating on an ECRIS. At the ISAC facility
      of TRIUMF, a 14.5 GHz PHOENIX booster which has
      been in operation since 2010 was recently upgraded
      to accommodate the two-frequency heating system
      using a single waveguide. The efficiency for charge
      breeding into a single charge state, which depends on
      the rare isotope that is being charge-bred, has been
      determined to be between 1 - 6 %. The CSB is being
      upgraded to improve its charge breeding efficiency. A
      detailed investigation of the effect of the twofrequency
      heating technique on the intensity,
      emittance and the efficiency of the extracted beam is
      presently being conducted.

      Speaker: Joseph Adegun (TRIUMF)
    • 14:35 14:45
      Studies of ECR Plasma Chamber Contamination With Accelerated Beams and Diamond Detectors 10m

      While developing stable and re-accelerated rare
      isotope beams (RIB) for acceleration with the TAMU
      K500 cyclotron, a background of various stable
      beams has been observed. It has been determined
      that this background is arising from alloys and
      contamination in the components of our ECR ion
      sources, in particular, the aluminum alloy plasma
      chamber. We have developed a detector system
      based on diamond detector telescopes that allows us
      to measure the composition of the beam after
      acceleration with the K500 cyclotron at TAMU. Using
      this technique, we have been able to develop ion
      source and cyclotron tuning methods to minimize the
      stable beam background and maximize the stable
      beams of interest and/or the RIBs. We also endeavor
      to reduce the stable beam background from the ECR
      ion sources using techniques such as pure aluminum
      liners. In my presentation, I plan to show our
      accelerated beam detection setup with diamond
      detectors. I also plan to present about the
      background we have measured with this setup from
      the ECRIS components, in particular, the plasma
      chamber. Finally, I will comment on our efforts to
      reduce this background.

      Speaker: Brian Roeder (Texas A&M University)
    • 14:45 15:05
      Break 20m
    • 15:05 15:35
      Closing Statement 30m
    • 15:35 15:55
      FRIB Tour Presentation 20m
    • 15:55 16:55
      FRIB Virtual Tour 1h
    • 16:55 16:56
      Adjourn 1m
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