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Sample records for ion cyclotron transmission

  1. Ion cyclotron transmission spectroscopy in the Tokamak Fusion Test Reactor

    SciTech Connect

    Greene, G.J.

    1993-09-01

    The propagation of waves in the ion cyclotron range of frequencies has been investigated experimentally in the Tokamak Fusion Test Reactor. A small, broadband, radiofrequency (rf) magnetic probe located outside the plasma limiter, at a major radius near that of the plasma center, was excited with a low power, frequency swept source (1--200 MHz). Waves propagating to a distant location were detected with a second, identical probe. The rf transmission spectrum revealed a region of attenuation over a band of frequencies for which the minority fundamental resonance was located between the outer plasma edge and the major radius of the probe location. Distinct, non-overlapping attenuation bands were observed from hydrogen and helium-3 minority species; a distinct tritium band should be observed in future DT experiments. Rapid spectrum acquisition during a helium-3 gas puff experiment showed that the wave attenuation involved the plasma core and was not a surface effect. A model in which the received power varied exponentially with the minority density, averaged over the resonance region, fit the time evolution of the probe signal relatively well. Estimation of a 1-d tunneling parameter from the experimental observations is discussed. Minority concentrations of less than 0.5 % can be resolved with this measurement.

  2. Transmission line component testing for the ITER Ion Cyclotron Heating and Current Drive System

    NASA Astrophysics Data System (ADS)

    Goulding, Richard; Bell, G. L.; Deibele, C. E.; McCarthy, M. P.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Barbier, C. N.; Cambell, I. H.; Moon, R. L.; Pesavento, P. V.; Fredd, E.; Greenough, N.; Kung, C.

    2014-10-01

    High power RF testing is underway to evaluate transmission line components for the ITER Ion Cyclotron Heating and Current Drive System. The transmission line has a characteristic impedance Z0 = 50 Ω and a nominal outer diameter of 305 mm. It is specified to carry up to 6 MW at VSWR = 1.5 for 3600 s pulses, with transient voltages up to 40 kV. The transmission line is actively cooled, with turbulent gas flow (N2) used to transfer heat from the inner to outer conductor, which is water cooled. High voltage and high current testing of components has been performed using resonant lines generating steady state voltages of 35 kV and transient voltages up to 60 kV. A resonant ring, which has operated with circulating power of 6 MW for 1 hr pulses, is being used to test high power, low VSWR operation. Components tested to date include gas barriers, straight sections of various lengths, and 90 degree elbows. Designs tested include gas barriers fabricated from quartz and aluminum nitride, and transmission lines with quartz and alumina inner conductor supports. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  3. Component tests for the ITER Ion Cyclotron Transmission Line and Matching System - Status and Plans

    NASA Astrophysics Data System (ADS)

    Goulding, R. H.; McCarthy, M. P.; Deibele, C. E.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Campbell, I. H.; Gray, S. L.; Moon, R. L.; Pesavento, P. V.; Sanabria, R. M.; Fredd, E.; Greenough, N.; Kung, C.

    2015-11-01

    New Z0 = 50 Ω gas-cooled component designs for the ITER Ion Cyclotron Heating and Current Drive System have been successfully tested at high RF power levels. They include two types featuring spoke-ring assembly (SRA) inner conductor supports: 20° elbows, and variable length assembly bellows, both achieving RF voltages > 35 kV peak, and currents ~ 760 A peak during quasi-steady state operation. The SRA utilizes mechanically preloaded fused quartz spokes, increasing lateral load handling capability. Components with SRA supports have been seismically tested, with no variation in low power electrical performance detected after testing. A 3 MW four-port switch has also been successfully tested at high RF power, and tests of a 6 MW hybrid power splitter are planned in the near future. Latest results will be presented. Plans for arc localization tests in a 60 m SRA transmission line run, and RF tests of Z0 = 50 Ω and Z0 = 20 Ω matching components with water-cooled inner conductors will also be discussed. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  4. Ion cyclotron resonance cell

    DOEpatents

    Weller, R.R.

    1995-02-14

    An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

  5. Ion cyclotron resonance cell

    DOEpatents

    Weller, Robert R.

    1995-01-01

    An ion cyclotron resonance cell having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions.

  6. ITER Ion Cyclotron Heating and Fueling Systems

    SciTech Connect

    Rasmussen, D.A.; Baylor, L.R.; Combs, S.K.; Fredd, E.; Goulding, R.H.; Hosea, J.; Swain, D.W.

    2005-04-15

    The ITER burning plasma and advanced operating regimes require robust and reliable heating and current drive and fueling systems. The ITER design documents describe the requirements and reference designs for the ion cyclotron and pellet fueling systems. Development and testing programs are required to optimize, validate and qualify these systems for installation on ITER.The ITER ion cyclotron system offers significant technology challenges. The antenna must operate in a nuclear environment and withstand heat loads and disruption forces beyond present-day designs. It must operate for long pulse lengths and be highly reliable, delivering power to a plasma load with properties that will change throughout the discharge. The ITER ion cyclotron system consists of one eight-strap antenna, eight rf sources (20 MW, 35-65 MHz), associated high-voltage DC power supplies, transmission lines and matching and decoupling components.The ITER fueling system consists of a gas injection system and multiple pellet injectors for edge fueling and deep core fueling. Pellet injection will be the primary ITER fuel delivery system. The fueling requirements will require significant extensions in pellet injector pulse length ({approx}3000 s), throughput (400 torr-L/s,) and reliability. The proposed design is based on a centrifuge accelerator fed by a continuous screw extruder. Inner wall pellet injection with the use of curved guide tubes will be utilized for deep fueling.

  7. Ion cyclotron waves at Titan

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Wei, H. Y.; Cowee, M. M.; Neubauer, F. M.; Dougherty, M. K.

    2016-03-01

    During the interaction of Titan's thick atmosphere with the ambient plasma, it was expected that ion cyclotron waves would be generated by the free energy of the highly anisotropic velocity distribution of the freshly ionized atmospheric particles created in the interaction. However, ion cyclotron waves are rarely observed near Titan, due to the long growth times of waves associated with the major ion species from Titan's ionosphere, such as CH4+ and N2+. In the over 100 Titan flybys obtained by Cassini to date, there are only two wave events, for just a few minutes during T63 flyby and for tens of minutes during T98 flyby. These waves occur near the gyrofrequencies of proton and singly ionized molecular hydrogen. They are left-handed, elliptically polarized, and propagate nearly parallel to the field lines. Hybrid simulations are performed to understand the wave growth under various conditions in the Titan environment. The simulations using the plasma and field conditions during T63 show that pickup protons with densities ranging from 0.01 cm-3 to 0.02 cm-3 and singly ionized molecular hydrogens with densities ranging from 0.015 cm-3 to 0.25 cm-3 can drive ion cyclotron waves with amplitudes of ~0.02 nT and of ~0.04 nT within appropriate growth times at Titan, respectively. Since the T98 waves were seen farther upstream than the T63 waves, it is possible that the instability was stronger and grew faster on T98 than T63.

  8. Method and apparatus for ion cyclotron spectrometry

    DOEpatents

    Dahl, David A [Idaho Falls, ID; Scott, Jill R [Idaho Falls, ID; McJunkin, Timothy R [Idaho Falls, ID

    2010-08-17

    An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber that includes at least a first section that induces a first magnetron effect that increases a cyclotron frequency of an ion and at least a second section that induces a second magnetron effect that decreases the cyclotron frequency of an ion. The cyclotron frequency changes induced by the first and second magnetron effects substantially cancel one another so that an ion traversing the at least first and second sections will experience no net change in cyclotron frequency.

  9. Ion Cyclotron Resonance Heating System on EAST

    NASA Astrophysics Data System (ADS)

    Wang, Lei

    2009-08-01

    Ion cyclotron resonance heating (ICRH) system which will provide at least than 10 MW heating power, with a frequency range from 25 MHz to 100 MHz, is being built up for the EAST. The system includes high-power and wide-frequency radio amplifier, transmission line as well as resonant double loop (RDL) antenna. As a part of this system a sub-ICRH system unit with a ultimate output power of 2.5 MW was set up and employed for heating experiment. The maximum of the launched power reached 200 kW in 2008.

  10. ECR (Electron Cyclotron Resonance) ion sources for cyclotrons

    SciTech Connect

    Lyneis, C.M.

    1986-10-01

    In the last decade ECR (Electron Cyclotron Resonance) ion sources have evolved from a single large, power consuming, complex prototype into a variety of compact, simple, reliable, efficient, high performance sources of high charge state ions for accelerators and atomic physics. The coupling of ECR sources to cyclotrons has resulted in significant performance gains in energy, intensity, reliability, and variety of ion species. Seven ECR sources are in regular operation with cyclotrons and numerous other projects are under development or in the planning stag. At least four laboratories have ECR sources dedicated for atomic physics research and other atomic physics programs share ECR sources with cyclotrons. An ECR source is now installed on the injector for the CERN SPS synchrotron to accelerate O/sup 8 +/ to relativistic energies. A project is underway at Argonne to couple an ECR source to a superconducting heavy-ion linac. Although tremendous progress has been made, the field of ECR sources is still a relatively young technology and there is still the potential for further advances both in source development and understanding of the plasma physics. The development of ECR sources is reviewed. The important physics mechanisms which come into play in the operation of ECR Sources are discussed, along with various models for charge state distributions (CSD). The design and performance of several ECR sources are compared. The 88-Inch Cyclotron and the LBL ECR is used as an example of cyclotron+ECR operation. The future of ECR sources is considered.

  11. Cyclotron axial ion-beam-buncher system

    SciTech Connect

    Hamm, R.W.; Swenson, D.A.; Wangler, T.P.

    1982-02-11

    Adiabatic ion bunching is achieved in a cyclotron axial ion injection system through the incorporation of a radio frequency quadrupole system, which receives ions from an external ion source via an accelerate-decelerate system and a focusing einzel lens system, and which adiabatically bunches and then injects the ions into the median plane of a cyclotron via an electrostatic quadrupole system and an inflection mirror.

  12. Method and apparatuses for ion cyclotron spectrometry

    DOEpatents

    Dahl, David A.; Scott, Jill R.; McJunkin, Timothy R.

    2012-03-06

    An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

  13. The electromagnetic ion cyclotron beam anisotropy instability

    NASA Technical Reports Server (NTRS)

    Peter Gary, S.; Schriver, David

    1987-01-01

    Electromagnetic instabilities driven by an anisotropic, relatively cool ion beam are studied for the case in which both the beam and the instabilities propagate parallel or antiparallel to a uniform magnetic field. At modest beam-core relative drift speeds, sufficiently large perpendicular-to-parallel beam temperature ratios and sufficiently large plasma beta, the mode of fastest growth rate is the ion cyclotron beam anisotropy instability. Because the right-hand polarized waves observed upstream of slow shocks in the earth's magnetotail can lead to the appropriate beam anisotropy, the ion cyclotron instability may be present and account for the left-hand polarized magnetic waves observed there. Also, because of its relatively low phase speed, the ion cyclotron beam anisotropy instability may provide the scattering necessary for ion Fermi acceleration at slow shocks of sufficiently high plasma beta.

  14. High intensity ion beam injection into the 88-inch cyclotron

    SciTech Connect

    Wutte, Daniela; Clark, Dave J.; Laune, Bernard; Leitner,Matthaeus A.; Lyneis, Claude M.

    2000-05-31

    Low cross section experiments to produce super-heavyelements have increased the demand for high intensity heavy ion beams atenergies of about 5 MeV/nucleon at the 88-Inch Cyclotron at the LawrenceBerkeley National Laboratory. Therefore, efforts are underway to increasethe overall ion beam transmission through the axial injection line andthe cyclotron. The ion beam emittance has been measured for various ionmasses and charge states. Beam transport simulations including spacecharge effects were performed for both of the injection line and the ionsource extraction. The relatively low nominal injection voltage of 10 kVwas found to be the main factor for ion beam losses, because of beam blowup due to space charge forces at higher intensities. Consequently,experiments and simulations have been performed at higherinjectionenergies, and it was demonstrated that the ion beams could still becentered in the cyclotron at these energies. Therefore, the new injectorion source VENUS and its ion beam transport system (currently underconstruction at the 88-Inch Cyclotron) are designed for extractionvoltages up to 30 kV.

  15. Xe/+/ -induced ion-cyclotron harmonic waves

    NASA Astrophysics Data System (ADS)

    Jones, D.

    Xenon ion sources on an ejectable package separated from the main payload during the flights of Porcupine rockets F3 and F4 which were launched from Kiruna, Sweden on March 19 and 31, 1979, respectively. The effects of the xenon ion beam, detected by the LF (f less than 16 kHz) wideband electric field experiment and analyzed by using a sonograph, are discussed. Particular attention is given to the stimulation of the ion-cyclotron harmonic waves which are usually linked to the local proton gyro-frequency, but are sometimes related to half that frequency. It was found that in a plasma dominated by O(+) ions, a small amount (1-10%) of protons could cause an effect such that the O(+) cyclotron harmonic waves are set up by the hydrogen ions, the net result being the observation of harmonic emissions separated by the hydrogen ion gyro frequency.

  16. Interpretive Experiments: An Interpretive Experiment in Ion Cyclotron Resonance Spectroscopy.

    ERIC Educational Resources Information Center

    Burnier, R. C.; Freiser, B. S.

    1979-01-01

    Provides a discussion which is intended for chemistry college students on the ion cyclotron resonance (ICR) spectroscopy, the physical basis for ion cyclotron resonance, and the experimental methodology employed by ICR spectroscopists. (HM)

  17. Influence of injection beam emittance on beam transmission efficiency in a cyclotron

    SciTech Connect

    Kurashima, Satoshi Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Yoshida, Ken-Ichi; Okumura, Susumu

    2014-02-15

    The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10{sup −9}–10{sup −6} ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a {sup 12}C{sup 5+} beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased.

  18. Ion-cyclotron instability in magnetic mirrors

    SciTech Connect

    Pearlstein, L.D.

    1987-02-02

    This report reviews the role of ion-cyclotron frequency instability in magnetic mirrors. The modes discussed here are loss-cone or anisotropy driven. The discussion includes quasilinear theory, explosive instabilities of 3-wave interaction and non-linear Landau damping, and saturation due to non-linear orbits. (JDH)

  19. Ion-beam-driven electrostatic ion cyclotron instabilities

    SciTech Connect

    Miura, A.; Okuda, H.; Ashour-Abdalla, M.

    1982-10-01

    We present results of numerical simulations on the electrostatic ion cyclotron instabilities driven by the ion beam parallel to the magnetic field. For the beam speed exceeding the thermal speed of background ions and the beam temperature much lower than the background ion temperature, it is found that the instability results in strong perpendicular heating and slowing down of parallel drift of the beam ions, leading to the saturation of the instability. Applications to plasma heating and space plasma physics are discussed.

  20. Ion cyclotron waves observed near the plasmapause

    NASA Technical Reports Server (NTRS)

    Fraser, B. J.; Samson, J. C.; Mcpherron, R. L.; Russell, C. T.

    1986-01-01

    Pc2 electromagnetic ion cyclotron waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE-1 and -2 between L = 7.6 - 5.8 on an inbound near equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width about 1 earth radius and penetrated about 1 earth radius into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He(+) and the warm (0.1-16 keV/e) O(+) and He(+) heavy ion populations. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by multicomponent cold plasma propagation theory are identified in the wave data. The results are considered as an example of wave-particle interactions occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase.

  1. Electrostatic ion cyclotron velocity shear instability

    NASA Technical Reports Server (NTRS)

    Lemons, D. S.; Winske, D.; Gary, S. P.

    1992-01-01

    A local electrostatic dispersion equation is derived for a shear flow perpendicular to an ambient magnetic field, which includes all kinetic effects and involves only one important parameter. The dispersion equation is cast in the form of Gordeyev integrals and is solved numerically. Numerical solutions indicate that an ion cyclotron instability is excited. The instability occurs roughly at multiples of the ion cyclotron frequency (modified by the shear), with the growth rate or the individual harmonics overlapping in the wavenumber. At large values of the shear parameter, the instability is confined to long wavelengths, but at smaller shear, a second distinct branch at shorter wavelengths also appears. The properties of the instability obtained are compared with those obtained in the nonlocal limit by Ganguli et al. (1985, 1988).

  2. Single-pass ion cyclotron resonance absorption

    SciTech Connect

    Breizman, Boris N.; Arefiev, Alexey V.

    2001-03-01

    The ion response to the rf-field during single-pass ion-cyclotron resonance heating (ICRH) can be essentially nonlinear. This paper presents a self-consistent theory of the rf-wave propagation and ion motion through the resonance. An important ingredient of the problem is the ion flow along the magnetic field. The flow velocity limits the time the ions spend at the resonance, which in turn limits the ion energy gain. A feature that makes the problem nonlinear is that the flow accelerates under the effect of the {nabla}B force and rf-pressure. This acceleration can produce a steep decrease in the plasma density at the resonance, resulting in partial reflection of the incident wave.

  3. Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Chen, Yu; Leach, Franklin E; Kaiser, Nathan K; Dang, Xibei; Ibrahim, Yehia M; Norheim, Randolph V; Anderson, Gordon A; Smith, Richard D; Marshall, Alan G

    2015-01-01

    Enhancements to the ion source and transfer optics of our 9.4 T Fourier transform ion cyclotron resonance (ICR) mass spectrometer have resulted in improved ion transmission efficiency for more sensitive mass measurement of complex mixtures at the MS and MS/MS levels. The tube lens/skimmer has been replaced by a dual ion funnel and the following octopole by a quadrupole for reduced ion cloud radial expansion before transmission into a mass-selective quadrupole. The number of ions that reach the ICR cell is increased by an order of magnitude for the funnel/quadrupole relative to the tube lens/skimmer/octopole. PMID:25601704

  4. Current driven electrostatic and electromagnetic ion cyclotron instabilities

    NASA Technical Reports Server (NTRS)

    Forslund, D. W.; Kennel, C. F.; Kindel, J. M.

    1971-01-01

    Growth rates and parameter dependences are calculated for the current driven instabilities of electrostatic (with finite-beta corrections) and electromagnetic ion cyclotron waves. For 0.25 (T sub e)/(T sub i) 2.5, ion cyclotron waves have large growth rates, while ion acoustic waves are still stable. In fusion devices, where electrostatic waves may be stable, electromagnetic ion cyclotron waves are unstable for beta sub i 0.001.

  5. Cyclotron resonance effects on stochastic acceleration of light ionospheric ions

    NASA Technical Reports Server (NTRS)

    Singh, N.; Schunk, R. W.; Sojka, J. J.

    1982-01-01

    The production of energetic ions with conical pitch angle distributions along the auroral field lines is a subject of considerable current interest. There are several theoretical treatments showing the acceleration (heating) of the ions by ion cyclotron waves. The quasi-linear theory predicts no acceleration when the ions are nonresonant. In the present investigation, it is demonstrated that the cyclotron resonances are not crucial for the transverse acceleration of ions by ion cyclotron waves. It is found that transverse energization of ionospheric ions, such as He(+), He(++), O(++), and O(+), is possible by an Electrostatic Hydrogen Cyclotron (EHC) wave even in the absence of cyclotron resonance. The mechanism of acceleration is the nonresonant stochastic heating. However, when there are resonant ions both the total energy gain and the number of accelerated ions increase with increasing parallel wave number.

  6. Cyclotron resonance effects on stochastic acceleration of light ionospheric ions

    NASA Astrophysics Data System (ADS)

    Singh, N.; Schunk, R. W.; Sojka, J. J.

    1982-09-01

    The production of energetic ions with conical pitch angle distributions along the auroral field lines is a subject of considerable current interest. There are several theoretical treatments showing the acceleration (heating) of the ions by ion cyclotron waves. The quasi-linear theory predicts no acceleration when the ions are nonresonant. In the present investigation, it is demonstrated that the cyclotron resonances are not crucial for the transverse acceleration of ions by ion cyclotron waves. It is found that transverse energization of ionospheric ions, such as He(+), He(++), O(++), and O(+), is possible by an Electrostatic Hydrogen Cyclotron (EHC) wave even in the absence of cyclotron resonance. The mechanism of acceleration is the nonresonant stochastic heating. However, when there are resonant ions both the total energy gain and the number of accelerated ions increase with increasing parallel wave number.

  7. The mirror and ion cyclotron anisotropy instabilities

    NASA Technical Reports Server (NTRS)

    Gary, S. P.

    1992-01-01

    The linear dispersion equation for fully electromagnetic waves and instabilities at arbitrary directions of propagation relative to a background magnetic field B(0) in a homogeneous Vlasov plasma is solved numerically for bi-Maxwellian particle distributions. For isotropic plasmas the dispersion and damping of the three modes below the proton cyclotron frequency are studied as functions of Beta(i) and T(e)/T(i). The transport ratios of helicity, cross-helicity, Alfven ratio, compressibility, and parallel compressibility are defined. Under the condition that the proton temperature perpendicular to B(0) is greater than the parallel temperature, the growth rates and transport ratios of the mirror instability and the ion cyclotron anisotropy instability are examined and compared. Both the proton parallel compressibility and the proton Alfven ratio are significantly different for the two growing modes.

  8. Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer

    SciTech Connect

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2015-01-19

    Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides unparalleled mass accuracy and resolving power.[1],[2] With electrospray ionization (ESI), ions are typically transferred into the mass spectrometer through a skimmer, which serves as a conductance-limiting orifice. However, the skimmer allows only a small fraction of incoming ions to enter the mass spectrometer. An ion funnel, originally developed by Smith and coworkers at Pacific Northwest National Laboratory (PNNL)[3-5] provides much more efficient ion focusing and transfer. The large entrance aperture of the ion funnel allows almost all ions emanating from a heated capillary to be efficiently captured and transferred, resulting in nearly lossless transmission.

  9. Electronuclear ion fusion in an ion cyclotron resonance reactor

    SciTech Connect

    Cowgill, Donald F.

    1996-12-01

    A method and apparatus for generating nuclear fusion by ion cyclotron resonance in an ion trap reactor. The reactor includes a cylindrical housing having an axial axis, an internal surface, and first and second ends. First and second end plates that are charged are respectively located at the first and second ends of the cylindrical housing. A gas layer is adsorbed on the internal surface of the cylindrical housing. Ions are desorbed from the gas layer, forming a plasma layer adjacent to the cylindrical housing that includes first ions that have a same charge sign as the first and second end plates. A uniform magnetic field is oriented along the axial axis of the cylindrical housing. Second ions, that are unlike the first ions, but have the same charge sign, are injected into the cylindrical housing along the axial axis of the cylindrical housing. A radio frequency field resonantly accelerates the injected second ions at the cyclotron resonance frequency of the second ions. The second ions circulate in increasing helical orbits and react with the first ions, at the optimum energy for nuclear fusion. The amplitude of the radio frequency field is adjusted to accelerate the second ions at a rate equal to the rate of tangential energy loss of the second ions by nuclear scattering in the first ions, causing the ions to continually interact until fusion occurs.

  10. Ion Behavior in an Electrically Compensated Ion Cyclotron Resonance Trap

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We recently described a new electrically compensated trap in FT ion cyclotron resonance mass spectrometry and developed a means of tuning traps of this general design. Here, we describe a continuation of that research by comparing the ion transient lifetimes and the resulting mass resolving powers and signal-to-noise (S/N) ratios that are achievable in the compensated vs. uncompensated modes of this trap. Transient lifetimes are ten times longer under the same conditions of pressure, providing improved mass resolving power and S/N ratios. The mass resolving power as a function of m/z is linear (log-log plot) and nearly equal to the theoretical maximum. Importantly, the ion cyclotron frequency as a function of ion number decreases linearly in accord with theory, unlike its behavior in the uncompensated mode. This linearity should lead to better control in mass calibration and increased mass accuracy than achievable in the uncompensated mode. PMID:21499521

  11. Ion cyclotron bands in VLF saucers

    NASA Technical Reports Server (NTRS)

    Maeda, Kaichi; Fung, Shing F.; Calvert, Wynne

    1990-01-01

    In the wideband VLF data obtained by the polar orbiting DE-1 satellite over the polar night ion trough region of the upper ionosphere, conspicuous frequency-band structures are found to occur both in absorption and emission, particularly associating with VLF saucers. The attenuation bands indicate that the ions of atomic hydrogen from the polar ionosphere are accelerated by the ac electric fields of VLF waves oscillating normal to the static magnetic field, analogous to a cyclotron accelerator. The observed frequencies of the cyclotron harmonics suggest that the acceleration is taking place in the layer below the satellite at a geocentric distance of less than about 1.5 earth radii. This example indicates the existence of upward propagating hiss at those altitudes inside the auroral zone. On the other hand, the frequency shifts of the emission bands are attributed to a combination of two different types of Doppler shift, one due to the orbital motion of the satellite and the other due to the upward motion of the medium at the emission source. This indicates the existence of an upward plasma flow at the source, with a velocity of the order of 20 km/s inside the saucer. The amount of this frequency shift decreases with increasing harmonic order, indicating a higher phase velocity for the electrostatic waves of higher harmonic order.

  12. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K.; Gallagher, D. L.; Kozyra, J. U.

    2007-01-01

    It is well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. [2002 - 2007]. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis

  13. Global Simulation of Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.; Gallagher, D. L.; Kozyra, J. U.

    2007-01-01

    It is very well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis of modern

  14. A room temperature electron cyclotron resonance ion source for the DC-110 cyclotron

    SciTech Connect

    Efremov, A. Bogomolov, S.; Lebedev, A.; Loginov, V.; Yazvitsky, N.

    2014-02-15

    The project of the DC-110 cyclotron facility to provide applied research in the nanotechnologies (track pore membranes, surface modification of materials, etc.) has been designed by the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (Dubna). The facility includes the isochronous cyclotron DC-110 for accelerating the intensive Ar, Kr, Xe ion beams with 2.5 MeV/nucleon fixed energy. The cyclotron is equipped with system of axial injection and ECR ion source DECRIS-5, operating at the frequency of 18 GHz. This article reviews the design and construction of DECRIS-5 ion source along with some initial commissioning results.

  15. Ion cyclotron emission studies: Retrospects and prospects

    NASA Astrophysics Data System (ADS)

    Gorelenkov, N. N.

    2016-05-01

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfvénic cyclotron instabilities with the linear growth rate √ {n_α /n_e } driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. More recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusion devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. We discuss further prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.

  16. Ion cyclotron emission studies: Retrospects and prospects

    DOE PAGESBeta

    Gorelenkov, N. N.

    2016-06-05

    Ion cyclotron emission (ICE) studies emerged in part from the papers by A.B. Mikhailovskii published in the 1970s. Among the discussed subjects were electromagnetic compressional Alfv,nic cyclotron instabilities with the linear growth rate similar ~ √(nα/ne) driven by fusion products, -particles which draw a lot of attention to energetic particle physics. The theory of ICE excited by energetic particles was significantly advanced at the end of the 20th century motivated by first DT experiments on TFTR and subsequent JET experimental studies which we highlight. Recently ICE theory was advanced by detailed theoretical and experimental studies on spherical torus (ST) fusionmore » devices where the instability signals previously indistinguishable in high aspect ratio tokamaks due to high toroidal magnetic field became the subjects of experiments. Finally, we discuss prospects of ICE theory applications for future burning plasma (BP) experiments such as those to be conducted in ITER device in France, where neutron and gamma rays escaping the plasma create extremely challenging conditions fusion alpha particle diagnostics.« less

  17. Fourth generation electron cyclotron resonance ion sources.

    PubMed

    Lyneis, Claude M; Leitner, D; Todd, D S; Sabbi, G; Prestemon, S; Caspi, S; Ferracin, P

    2008-02-01

    The concepts and technical challenges related to developing a fourth generation electron cyclotron resonance (ECR) ion source with a rf frequency greater than 40 GHz and magnetic confinement fields greater than twice B(ECR) will be explored in this article. Based on the semiempirical frequency scaling of ECR plasma density with the square of operating frequency, there should be significant gains in performance over current third generation ECR ion sources, which operate at rf frequencies between 20 and 30 GHz. While the third generation ECR ion sources use NbTi superconducting solenoid and sextupole coils, the new sources will need to use different superconducting materials, such as Nb(3)Sn, to reach the required magnetic confinement, which scales linearly with rf frequency. Additional technical challenges include increased bremsstrahlung production, which may increase faster than the plasma density, bremsstrahlung heating of the cold mass, and the availability of high power continuous wave microwave sources at these frequencies. With each generation of ECR ion sources, there are new challenges to be mastered, but the potential for higher performance and reduced cost of the associated accelerator continues to make this a promising avenue for development. PMID:18315111

  18. Ion trajectories in an electrostatic ion guide for external ion source fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Marto, J A; Marshall, A G; May, M A; Limbach, P A

    1995-10-01

    An electrostatic ion guide (EIG) that consists of concentric cylinder and central wire electrodes can transport ions efficiently from an external ion source to an ion cyclotron resonance (ICR) ion trap for mass analysis, with several advantages over current injection methods. Because the electrostatic force of the EIG captures ions in a stable orbit about the wire electrode, ions with initially divergent trajectories may be redirected toward the ICR ion trap for improved ion transmission efficiency. SIMION trajectory calculations (ion kinetic energy, 1-200 eV; elevation angle, 0.30 °; azimuthal angle, 0.360°) predict that ions of m/z 1000 may be transmitted through a strong (0.01 → 3.0-T) magnetic field gradient. Judicious choice of ion source position and EIG potential minimizes the spread in ion axial kinetic energy at the ICR ion trap. Advantages of the EIG include large acceptance angle, even for ions that have large initial kinetic energy and large radial displacement with respect to the central z-axis, low ion extraction voltage (5-20 V), and efficient trapping because ions need not be accelerated to high velocity to pass through the magnetic field gradient. PMID:24214038

  19. Response of thermal ions to electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.

    1994-01-01

    Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

  20. Electromagnetic ion/ion cyclotron instability - Theory and simulations

    NASA Technical Reports Server (NTRS)

    Winske, D.; Omidi, N.

    1992-01-01

    Linear theory and 1D and 2D hybrid simulations are employed to study electromagnetic ion/ion cyclotron (EMIIC) instability driven by the relative streaming of two field-aligned ion beams. The characteristics of the instability are studied as a function of beam density, propagation angle, electron-ion temperature ratios, and ion beta. When the propagation angle is near 90 deg the EMIIC instability has the characteristics of an electrostatic instability, while at smaller angles electromagnetic effects play a significant role as does strong beam coupling. The 2D simulations point to a narrowing of the wave spectrum and accompanying coherent effects during the linear growth stage of development. The EMIIC instability is an important effect where ion beta is low such as in the plasma-sheet boundary layer and upstream of slow shocks in the magnetotail.

  1. Ion Cyclotron Waves in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Wei, H. Y.; Jian, L. K.; Russell, C. T.; Omidi, N.

    2016-02-01

    The ion cyclotron waves (ICWs) refer to electromagnetic transverse waves with nearly field-aligned propagation, circular polarization, and frequencies near the proton gyro-frequency. This chapter presents the ICW studies observed in the solar wind over a wide range of heliocentric distances, at all solar longitudes, and at locations far from planets or comets. To better understand the wave source region, case studies have been performed on a special group of ICW storm events, in which the left-handed (LH) and right-handed (RH) waves were observed simultaneously in the spacecraft frame. The study in the chapter assumes the waves are generated through one possible mechanism (i.e., the temperature anisotropy instability). The variations of the wave properties with heliocentric distances may also provide information on the possible wave generation sources and the effects of the wave to the solar wind plasma.

  2. Folded waveguide coupler for ion cyclotron heating

    SciTech Connect

    Owens, T.L.; Chen, G.L.

    1986-01-01

    A new type of waveguide coupler for plasma heating in the ion cyclotron range of frequencies is described. The coupler consists of a series of interleaved metallic vanes within a rectangular enclosure analogous to a wide rectangular waveguide that has been ''folded'' several times. At the mouth of the coupler, a plate is attached which contains coupling apertures in each fold or every other fold of the waveguide, depending upon the wavenumber spectrum desired. This plate serves primarily as a wave field polarizer that converts coupler fields to the polarization of the fast magnetosonic wave within the plasma. Theoretical estimates indicate that the folded waveguide is capable of high-efficiency, multimegawatt operation into a plasma. Bench tests have verified the predicted field structure within the waveguide in preparation for high-power tests on the Radio Frequency Test Facility at the Oak Ridge National Laboratory.

  3. Mirror and ion cyclotron anisotropy instabilities in the magnetosheath

    NASA Technical Reports Server (NTRS)

    Mckean, M. E.; Winske, D.; Gary, S. P.

    1992-01-01

    The kinetic properties of the ion cyclotron anisotropy and the mirror instabilities are investigated using one-dimensional hybrid simulations. It is found that, for moderate values of the ion beta and the proton temperature anisotropy, the two instabilities produce similar levels of turbulence. For high values of beta or temperature anisotropy, the ion cyclotron instability produces higher fluctuation levels of turbulence than does the mirror instability.

  4. Simulations of ion cyclotron anisotropy instabilities in the terrestrial magnetosheath

    NASA Technical Reports Server (NTRS)

    Gary, S. P.; Winske, Dan

    1993-01-01

    Enhanced transverse magnetic fluctuations observed below the proton cyclotron frequency in the terrestrial magnetosheath have been identified as due to the proton cyclotron and helium cyclotron instabilities driven by the T-perpendicular greater than T-parallel condition of the sheath ions. One-dimensional hybrid computer simulations are used here to examine the nonlinear properties of these two growing modes at relatively weak fluctuation energies and for wave vectors parallel to the background magnetic field. Second-order theory predicts fluctuating magnetic field energies at saturation of the proton cyclotron anisotropy instability in semiquantitative agreement with the simulation results. Introduction of the helium component enhances the wave-particle exchange rate for proton anisotropy reduction by that instability, thereby reducing the saturation energy of that mode. The simulations demonstrate that wave-particle interactions by the proton cyclotron and helium cyclotron instabilities lead to the anticorrelation observed by Anderson and Fuselier (1993).

  5. Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

    SciTech Connect

    Skalyga, V.; Izotov, I.; Mansfeld, D.; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O.

    2015-08-15

    Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities.

  6. Nonresonant interaction of heavy ions with electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Berchem, J.; Gendrin, R.

    1985-01-01

    The motion of a heavy ion in the presence of an intense ultralow-frequency electromagnetic wave propagating along the dc magnetic field is analyzed. Starting from the basic equations of motion and from their associated two invariants, the heavy ion velocity-space trajectories are drawn. It is shown that after a certain time, particles whose initial phase angles are randomly distributed tend to bunch together, provided that the wave intensity b-sub-1 is sufficiently large. The importance of these results for the interpretation of the recently observed acceleration of singly charged He ions in conjunction with the occurrence of large-amplitude ion cyclotron waves in the equatorial magnetosphere is discussed.

  7. Convection of ion cyclotron waves to ion-heating regions

    SciTech Connect

    Roennmark, K.; Andre, M. )

    1991-10-01

    Low-frequency waves associated with ion conics have been observed in the central plasma sheet, in a region where there are no obvious sources of free energy that could destabilize these waves locally. The authors consider ion cyclotron waves generated in the equatorial plane by a proton temperature anisotropy and use computed growth rates to create a model wave distribution. Using ray tracing and conservation of the wave distribution function along phase space rays, they then map the wave intensities form the equatorial plane to the top of the ion-heating region. They find that the spectral density at a geocentric distance of 2.8 R{sub E} will be about 10 times higher than that in the equatorial region. Thus, convection from the equatorial plane could explain the observed spectral density of 10{sup {minus}6} V{sup 2} m{sup {minus}2} Hz{sup {minus}1} and the associated oxygen ion heating.

  8. An electron cyclotron resonance ion source based low energy ion beam platform.

    PubMed

    Sun, L T; Shang, Y; Ma, B H; Zhang, X Z; Feng, Y C; Li, X X; Wang, H; Guo, X H; Song, M T; Zhao, H Y; Zhang, Z M; Zhao, H W; Xie, D Z

    2008-02-01

    To satisfy the requirements of surface and atomic physics study in the field of low energy multiple charge state ion incident experiments, a low energy (10 eV/q-20 keV/q) ion beam platform is under design at IMP. A simple test bench has been set up to test the ion beam deceleration systems. Considering virtues such as structure simplicity, easy handling, compactness, cost saving, etc., an all-permanent magnet ECRIS LAPECR1 [Lanzhou all-permanent magnet electron cyclotron resonance (ECR) ion source No. 1] working at 14.5 GHz has been adopted to produce intense medium and low charge state ion beams. LAPECR1 source has already been ignited. Some intense low charge state ion beams have been produced on it, but the first test also reveals that many problems are existing on the ion beam transmission line. The ion beam transmission mismatches result in the depressed performance of LAPECR1, which will be discussed in this paper. To obtain ultralow energy ion beam, after being analyzed by a double-focusing analyzer magnet, the selected ion beam will be further decelerated by two afocal deceleration lens systems, which is still under design. This design has taken into consideration both ions slowing down and also ion beam focusing. In this paper, the conceptual design of deceleration system will be discussed. PMID:18315202

  9. Ion source and injection line for high intensity medical cyclotron

    SciTech Connect

    Jia, XianLu Guan, Fengping; Yao, Hongjuan; Zhang, TianJue; Yang, Jianjun; Song, Guofang; Ge, Tao; Qin, Jiuchang

    2014-02-15

    A 14 MeV high intensity compact cyclotron, CYCIAE-14, was built at China Institute of Atomic Energy (CIAE). An injection system based on the external H− ion source was used on CYCIAE-14 so as to provide high intensity beam, while most positron emission tomography cyclotrons adopt internal ion source. A beam intensity of 100 μA/14 MeV was extracted from the cyclotron with a small multi-cusp H− ion source (CIAE-CH-I type) and a short injection line, which the H− ion source of 3 mA/25 keV H− beam with emittance of 0.3π mm mrad and the injection line of with only 1.2 m from the extraction of ion source to the medial plane of the cyclotron. To increase the extracted beam intensity of the cyclotron, a new ion source (CIAE-CH-II type) of 9.1 mA was used, with maximum of 500 μA was achieved from the cyclotron. The design and test results of the ion source and injection line optimized for high intensity acceleration will be given in this paper.

  10. Cyclotron Mode Frequency Shifts in Multi-Species Ion Plasmas

    NASA Astrophysics Data System (ADS)

    Affolter, Matthew

    2014-10-01

    Plasmas exhibit a variety of cyclotron modes, which are used in a broad range of devices to manipulate and diagnose charged particles. Here we discuss cyclotron modes in trapped plasmas with a single sign of charge. Collective effects and electric fields shift these cyclotron mode frequencies away from the ``bare'' cyclotron frequencies Ωs ≡ qB /ms c for each species s. These electric fields may arise from applied trap potentials, from space charge including collective effects, and from image charge in the trap walls. We will describe a new laser-thermal cyclotron spectroscopy technique, applied to well-diagnosed pure ion plasmas. This technique enables detailed observations of cos (mθ) surface cyclotron modes with m = 0 , 1, and 2 in near rigid-rotor multi-species ion plasmas. For each species s, we observe cyclotron mode frequency shifts which are dependent on the plasma density through the E × B rotation frequency, and on the charge concentration of species s, in close agreement with recent theory. This includes the novel m = 0 radial ``breathing'' mode, which generates no external electric field except at the plasma ends. These cyclotron frequencies can be used to determine the plasma E × B rotation frequency and the species charge concentrations, in close agreement with our laser diagnostics. Here, this plasma characterization permits a determination of the ``bare'' cyclotron frequencies to an accuracy of 2 parts in 104. These new results give a physical basis for the ``space charge'' and ``amplitude'' calibration equations of cyclotron mass spectroscopy, widely used in molecular chemistry and biology. Also, at high temperatures there is preliminary evidence that radially-standing electrostatic Bernstein waves couple to the surface cyclotron modes, producing new resonant frequencies. Supported by NSF/DOE Partnership grants PHY-0903877 and DE-SC0002451.

  11. Ring Current Ion Coupling with Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2002-01-01

    A new ring current global model has been developed for the first time that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes wave evolution of electromagnetic ion cyclotron waves (EMIC). The coupled model is able to simulate, for the first time self-consistently calculated RC ion kinetic and evolution of EMIC waves that propagate along geomagnetic field lines and reflect from the ionosphere. Ionospheric properties affect the reflection index through the integral Pedersen and Hall coductivities. The structure and dynamics of the ring current proton precipitating flux regions, intensities of EMIC, global RC energy balance, and some other parameters will be studied in detail for the selected geomagnetic storms. The space whether aspects of RC modelling and comparison with the data will also be discussed.

  12. Ring Current Ion Coupling with Electromagnetic Ion Cyclotron Waves

    NASA Technical Reports Server (NTRS)

    Khazanov. G. V.; Gamayunov, K. V.; Jordanova, V. K.; Six, N. Frank (Technical Monitor)

    2002-01-01

    A new ring current global model has been developed that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes wave evolution of electromagnetic ion cyclotron waves (EMIC). The coupled model is able to simulate, for the first time self-consistently calculated RC ion kinetic and evolution of EMIC waves that propagate along geomagnetic field lines and reflect from the ionosphere. Ionospheric properties affect the reflection index through the integral Pedersen and Hall conductivities. The structure and dynamics of the ring current proton precipitating flux regions, intensities of EMIC global RC energy balance, and some other parameters will be studied in detail for the selected geomagnetic storms.

  13. A laboratory study of collisional electrostatic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Suszcynsky, D. M.; Cartier, S. L.; Merlino, R. L.; Dangelo, N.

    1986-01-01

    The effects of neutral-particle collisions on electrostatic ion cyclotron instability are analyzed. Experiments were conducted in the Q machine of Motley (1975) with a cesium plasma in which the neutral gas pressure in the main chamber varied from about 5 microtorr-10 mtorr. The relation between electrostatic ion cyclotron wave amplitude and frequency and neutral argon pressure is examined. It is observed that over the full range of neutral pressure the frequency changes by less than 10 percent and the ion cyclotron waves continue to be excited and reach amplitudes of at least several percent at values of the neutral pressure where the ion-neutral collision frequency/ion gyrofrequency is about 0.3.

  14. Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer

    DOE PAGESBeta

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2015-01-19

    Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides unparalleled mass accuracy and resolving power.[1],[2] With electrospray ionization (ESI), ions are typically transferred into the mass spectrometer through a skimmer, which serves as a conductance-limiting orifice. However, the skimmer allows only a small fraction of incoming ions to enter the mass spectrometer. An ion funnel, originally developed by Smith and coworkers at Pacific Northwest National Laboratory (PNNL)[3-5] provides much more efficient ion focusing and transfer. The large entrance aperture of the ion funnel allows almost all ions emanating from a heated capillary to be efficiently captured and transferred, resulting inmore » nearly lossless transmission.« less

  15. Gas breakdown in electron cyclotron resonance ion sources

    NASA Astrophysics Data System (ADS)

    Skalyga, V. A.; Zorin, V. G.; Izotov, I. V.; Sidorov, A. V.; Lamy, T.; Sortais, P.; Thuillier, T.

    2006-03-01

    The realization of the beta-beam project (http://beta-beam.web.cern.ch/beta-beam/) assumes the formation of a pulsed ion beam of helium and neon radioactive isotopes. A pulsed electron cyclotron resonance (ECR) source of multicharged ions has been proposed to produce such a beam [P. Sortais et al., Rev. Sci. Instrum. 75, 1610 (2004)]. The rising of plasma density up to a stationary level must be fast enough to actualize this approach. This condition is mandatory to avoid particle losses in the transmission line. In the presented work, the rising time of the plasma density in an ECR ion source from a background level up to 98% of a stationary level is calculated. A zero-dimensional model of plasma formation in a mirror trap [V. Semenov et al., Rev. Sci. Instrum. 73, 635 (2002)] is used, able to make calculation for a wide range of microwave frequencies. Plasma confinement regime can either be classic (Pastoukhov [Rev. Plasma Phys. 13, 203 (1987)]) or gas dynamic, depending on the plasma parameters. The calculations are in good agreement with the experimental results obtained at the SMIS'37 setup. Numerical calculations also show that particle losses can be significantly reduced by pumping effect; thanks to microwave frequency increase above 40GHz.

  16. Nonlinear particle simulation of ion cyclotron waves in toroidal geometry

    SciTech Connect

    Kuley, A. Lin, Z.; Bao, J.; Wei, X. S.; Xiao, Y.

    2015-12-10

    Global particle simulation model has been developed in this work to provide a first-principles tool for studying the nonlinear interactions of radio frequency (RF) waves with plasmas in tokamak. In this model, ions are considered as fully kinetic particles using the Vlasov equation and electrons are treated as guiding centers using the drift kinetic equation with realistic electron-to-ion mass ratio. Boris push scheme for the ion motion has been developed in the toroidal geometry using magnetic coordinates and successfully verified for the ion cyclotron and ion Bernstein waves in global gyrokinetic toroidal code (GTC). The nonlinear simulation capability is applied to study the parametric decay instability of a pump wave into an ion Bernstein wave side band and a low frequency ion cyclotron quasi mode.

  17. Electron cyclotron resonance ion source DECRIS-4 for the U400 cyclotron

    SciTech Connect

    Leporis, M.; Bekhterev, V.; Bogomolov, S.; Efremov, A.; Gulbekian, G.; Kostyukhov, Yu.; Lebedev, A.; Loginov, V.; Yazvitsky, N.

    2006-03-15

    The electron cyclotron resonance ion source DECRIS-4 has been designed and constructed at the FLNR to be used as a second injector of heavy multiply charged ions for the U-400 cyclotron. After the modification of the injection side this source can be also used as a 'charge breeder' (the ''1{sup +}{yields}n{sup +}'' method) for the second phase of the Dubna radioactive ion beams project. The main feature of the ion source design is the creation of the extended resonance zone in a comparatively compact electron cyclotron resonance ion source. For this purpose the axial magnetic field is formed with a flat minimum. In this case the superposition of the axial magnetic field and the radial field of the permanent-magnet hexapole, made from NdFeB, allows one to create a larger resonance volume. For the plasma heating a microwave frequency of 14 GHz is used. In this paper we will present the basic design features of the ion source, including the results of the magnetic-field measurements. Some preliminary results of ion source tests are also reported.

  18. Heavy-ion injection from tandems into an isochronous cyclotron

    SciTech Connect

    LeVine, M.J.; Chasman, C.

    1981-01-01

    A design has been realized for the injection of heavy ion beams generated by the BNL 3-stage tandem facility into a proposed isochronous cyclotron. The tandem beams are bunched into +- 1/sup 0/ R.F. phase (less than or equal to 0.5 nsec) in two stages. The beam is then injected into the cyclotron through a valley, past a hill, and into the next valley on to a stripper foil. Only a single steerer is required to make trajectory corrections for the different beams. Two achromats are used to regulate the tandem potential and to provide phase control. A final section of the injection optics provides matching of transverse phase space to the acceptance of the cyclotron. The calculations use realistic tandem emittances and magnetic fields for the cyclotron based on measurements with a model magnet.

  19. Development of a high current H(-) ion source for cyclotrons.

    PubMed

    Etoh, H; Aoki, Y; Mitsubori, H; Arakawa, Y; Mitsumoto, T; Yajima, S; Sakuraba, J; Kato, T; Okumura, Y

    2014-02-01

    A multi-cusp DC H(-) ion source has been designed and fabricated for medical applications of cyclotrons. Optimization of the ion source is in progress, such as the improvement of the filament configuration, magnetic filter strength, extraction electrode's shape, configuration of electron suppression magnets, and plasma electrode material. A small quantity of Cs has been introduced into the ion source to enhance the negative ion beam current. The ion source produced 16 mA of DC H(-) ion beam with the Cs-seeded operation at a low arc discharge power of 2.8 kW. PMID:24593547

  20. Shear-flow-driven ion cyclotron and ion sound-drift instabilities of cylindrical inhomogeneous plasma

    SciTech Connect

    Mikhailenko, V. S.; Chibisov, D. V.

    2007-08-15

    The effects of the shear flow along the magnetic field on the development of the ion cyclotron, ion sound, and drift instabilities in the radially inhomogeneous cylindrical plasma are studied on the ground of a kinetic approach. It is shown that flow shear not only modifies the frequencies and growth rates of known current driven electrostatic ion cyclotron, ion sound, and drift instabilities, but is the source of the development of specific shear-flow-driven ion cyclotron, ion sound, and drift instabilities. These instabilities are excited at the levels of current along the ambient magnetic field which is below the critical value for the development of the modified by flow shear current driven ion cyclotron, ion sound, and drift instabilities.

  1. Linear analysis of ion cyclotron interaction in a multicomponent plasma

    NASA Technical Reports Server (NTRS)

    Gendrin, R.; Ashour-Abdalla, M.; Omura, Y.; Quest, K.

    1984-01-01

    The mechanism by which hot anisotropic protons generate electromagnetic ion cyclotron waves in a plasma containing cold H(+) and He(+) ions is quantitatively studied. Linear growth rates (both temporal and spatial) are computed for different plasma parameters: concentration, temperature,and anisotropy of cold He(+) ions and of hot protons. It is shown that: (1) for parameters typical of the geostationary altitude the maximum growth rates are not drastically changed when a small proportion (about 1 to 20 percent) of cold He(+) ions is present; (2) because of the important cyclotron absorption by thermal He(+) ions in the vicinity of the He(+) gyrofrequency, waves which could resonate with the bulk of the He(+) distribution cannot be generated. Therefore quasi-linear effects, in a homogeneous medium at least, cannot be responsible for the heating of He(+) ions which is often observed in conjunction with ion cyclotron waves. The variation of growth rate versus wave number is also studied for its importance in selecting suitable parameters in numerical simulation experiments.

  2. Ion cyclotron heating experiments in magnetosphere plasma device RT-1

    SciTech Connect

    Nishiura, M. Yoshida, Z.; Yano, Y.; Kawazura, Y.; Saitoh, H.; Yamasaki, M.; Mushiake, T.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-12-10

    The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ∼10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ∼50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

  3. Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2

    NASA Technical Reports Server (NTRS)

    Fraser, B. J.; Samson, J. C.; Hu, Y. D.; Mcpherron, R. L.; Russell, C. T.

    1992-01-01

    The first results of observations of ion cyclotron waves by the elliptically orbiting ISEE 1 and 2 pair of spacecraft are reported. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to the local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event is attributed to the modulation of this energy source by the Pc 5 waves seen at the same time.

  4. Miniature cyclotron resonance ion source using small permanent magnet

    NASA Technical Reports Server (NTRS)

    Anicich, V. G.; Huntress, W. T., Jr. (Inventor)

    1980-01-01

    An ion source using the cyclotron resonance principle is described. A miniaturized ion source device is used in an air gap of a small permanent magnet with a substantially uniform field in the air gap of about 0.5 inch. The device and permanent magnet are placed in an enclosure which is maintained at a high vacuum (typically 10 to the minus 7th power) into which a sample gas can be introduced. The ion beam end of the device is placed very close to an aperture through which an ion beam can exit into the apparatus for an experiment.

  5. LH wave absorption by mode conversion near ion cyclotron harmonics

    SciTech Connect

    Ko, K.; Bers, A.; Fuchs, V.

    1981-02-01

    Numerical studies of the dispersion relation near the lower-hybrid frequency in an inhomogeneous plasma (..delta.. n, ..delta.. T, ..delta.. B) show that portions of an incident lower-hybrid wave spectrum undergo successive but partial mode conversions to warm-plasma waves in the presence of ion cyclotron harmonics. Wave absorption beyond the first mode conversion occurs near an ion cyclotron harmonic where ion Landau damping is enhanced. A second-order dispersion relation numerically in good agreement with the full dispersion relation in the mode conversion region is derived using the condition par. delta D/par. delta k = 0. The mode conversion efficiency at each confluence is evaluated by solving the corresponding differential equation.

  6. RF Heating in Electron Cyclotron Resonance Ion Sources

    NASA Astrophysics Data System (ADS)

    Mascali, D.; Gammino, S.; Celona, L.; Ciavola, G.

    2011-12-01

    ECRIS—Electron Cyclotron Resonance Ion Sources are able to feed accelerators with intense currents of highly charged ions. In ECRIS a high density—high temperature plasma is generated by means of the Electron Cyclotron Resonance Heating inside a B-min, MHD stable trap. The state of the art about the principal heating mechanisms will be given. The paper will specially discuss the most critical and still open issues concerning the influence of the magnetic field and of the RF frequency on the plasma heating, as well as the impact of possible non-linear pumping wave—to—plasma interactions. The contribution of INFN-LNS will be specifically underlined. A short review on the future perspectives for the design of new generation ion sources will be given in conclusion.

  7. Evidence that the electrostatic ion cyclotron instability is saturated by ion heating. [in auroral arc

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.; Bering, E. A.; Mozer, F. S.

    1975-01-01

    Observations have been made of electric field oscillations near the local ion gyro frequency and of an intense beam of plasma ions at the edge of an auroral arc. The observations are in good agreement with ion heating as the saturation mechanism for electrostatic ion cyclotron waves.

  8. The multi-ion, multi-event test of ion cyclotron resonance heating

    NASA Technical Reports Server (NTRS)

    Persoon, Ann M.

    1993-01-01

    The multi-ion, multi-event study of ion cyclotron resonance heating was funded to study ion energization through ion cyclotron resonance with low frequency broadband electromagnetic turbulence. The initial work on the ion cyclotron resonance heating (ICRH) of oxygen ions was presented in Crew et al. Crew and his co-authors developed a two-parameter representation of selected oxygen conic distributions and modeled the conic formation in terms of resonance heating. The first year seeks to extend the work of Crew and his co-authors by testing the applicability of the ICRH mechanism to helium ion conic distributions, using data obtained from the Energetic Ion Composition Spectrometer and the Plasma Wave Instrument on Dynamics Explorer 1.

  9. Multi-ion, multi-event test of ion cyclotron resonance heating

    NASA Technical Reports Server (NTRS)

    Persoon, Ann M.

    1993-01-01

    The multi-ion, multi-event study of ion cyclotron resonance heating has been funded to study ion energization through ion cyclotron resonance with low frequency broadband electromagnetic turbulence. The modeling algorithm for the ion cyclotron resonance heating (ICRH) of oxygen ions was presented in Crew et al. (1990). Crew and his co-authors developed a two-parameter representation of selected oxygen conic distributions and modelled the conic formation in terms of resonance heating. The first year of this study seeks to extend the work of Crew and his co-authors by testing the applicability of the ICRH mechanism to helium ion conic distributions, using data obtained from the Energetic Ion Composition Spectrometer and the Plasma Wave Instrument on Dynamics Explorer 1.

  10. Theory for broadband detection of ion cyclotron resonance signals

    NASA Astrophysics Data System (ADS)

    McIver, Robert T.; Ledford, Edward B.; Hunter, Richard L.

    1980-02-01

    A complete line shape theory is developed for the transient response of a new type of ion cyclotron resonance (ICR) detector circuit. The detector is basically a balanced capacitance bridge which is sensitive to the abundance of gaseous ions stored in a static magnetic ion trap. For the first time, the equations of motion of ions in the ICR analyzer cell are shown to be coupled to the circuit equations of the detector. Also, the effect of nonreactive ion-molecule collisions on line shapes and on the transient response of the detector are analyzed and shown to allow measurement of ion-molecule collisions frequencies as a function of ion translational energy. One of the most important features of the capacitance bridge detector is its broadband sensitivity to a wide range of ion cyclotron resonance frequencies. This allows a mass spectrum of ions stored in the ICR analyzer cell to be obtained by scanning the frequency ω1 of the irradiating rf electric field at a fixed magnetic field strength. The capacitance bridge circuit can serve not only as a direct replacement for marginal oscillator circuits traditionally used in ICR experiments, but also as the detector for recently developed Fourier Transform and Rapid Scan ICR experiments.

  11. Loss-cone-driven ion cyclotron waves in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Denton, Richard E.; Hudson, Mary K.; Roth, Ilan

    1992-01-01

    The study examines the theoretical properties of linear ion cyclotron waves propagating in the magnetosphere at arbitrary angles to the background magnetic field. It is found that in some cases the linear wave growth of modes with oblique propagation can dominate that of the parallel propagating electromagnetic ion cyclotron (EMIC) wave. The growth rate of the loss-cone-driven mode depends strongly on the depth of the loss cone. A simple analytical theory which explains the scaling of the growth rate of the oblique mode with respect to various parameters is presented. The loss-cone-driven mode is an electromagnetic mode which is preferentially nearly linearly polarized. The wave field which results from the oblique mode in its perferentially nearly linearly polarized form are nearly perpendicular to B0 and are such that they may be difficult to distinguish from those of a linearly polarized parallel propgating EMIC wave.

  12. Heating by waves in the ion cyclotron frequency range

    SciTech Connect

    Koch, R.

    1996-03-01

    The main aspects of heating with the fast wave in the ion cyclotron range of frequencies (ICRF) are reviewed. First, the ion cyclotron resonance mechanism, fundamental and harmonics, is examined. Then the properties of fast wave dispersion are reviewed, and the principles of minority and higher cylcotron harmonic heating are discussed. An elementary coupling model is worked out in order to outline the computation of the electrical properties of ICRF antennas. Using the simple model, the antenna radiation pattern inside the plasma is computed and the effect of phasing on the k spectrum and on the antenna radiation properties is illustrated. The quasi linear-Fokker-Planck computation of the deformation of distribution functions due to Radio-Frequency (RF) and tail formation are briefly discussed. 11 refs., 5 figs.

  13. Electrostatic ion-cyclotron waves in magnetospheric plasmas Nonlocal aspects

    NASA Technical Reports Server (NTRS)

    Ganguli, G.; Bakshi, P.; Palmadesso, P.

    1984-01-01

    The importance of the effect of the magnetic shear and the finite size of current channel on the electrostatic ion-cyclotron instability for the space plasmas is illustrated. A non-local treatment is used. When the channel width Lc, is larger than the shear length Ls, there is a large reduction in the growth rate along with a noteworthy reduction of the band of the unstable perpendicular wavelengths. For Lc less than or = Ls/10 the growth rate is not much altered from its local value, however for Lc/pi i less than or = 10 to the second power the growth rate starts falling below the local value and vanishes for Lc pi i. The non-local effects lead to enhanced coherence in the ion cyclotron waves. Previously announced in STAR as N84-14917

  14. Linear and nonlinear physics of the magnetoacoustic cyclotron instability of fusion-born ions in relation to ion cyclotron emission

    SciTech Connect

    Carbajal, L. Cook, J. W. S.; Dendy, R. O.; Chapman, S. C.

    2014-01-15

    The magnetoacoustic cyclotron instability (MCI) probably underlies observations of ion cyclotron emission (ICE) from energetic ion populations in tokamak plasmas, including fusion-born alpha-particles in JET and TFTR [Dendy et al., Nucl. Fusion 35, 1733 (1995)]. ICE is a potential diagnostic for lost alpha-particles in ITER; furthermore, the MCI is representative of a class of collective instabilities, which may result in the partial channelling of the free energy of energetic ions into radiation, and away from collisional heating of the plasma. Deep understanding of the MCI is thus of substantial practical interest for fusion, and the hybrid approximation for the plasma, where ions are treated as particles and electrons as a neutralising massless fluid, offers an attractive way forward. The hybrid simulations presented here access MCI physics that arises on timescales longer than can be addressed by fully kinetic particle-in-cell simulations and by analytical linear theory, which the present simulations largely corroborate. Our results go further than previous studies by entering into the nonlinear stage of the MCI, which shows novel features. These include stronger drive at low cyclotron harmonics, the re-energisation of the alpha-particle population, self-modulation of the phase shift between the electrostatic and electromagnetic components, and coupling between low and high frequency modes of the excited electromagnetic field.

  15. Linear and nonlinear physics of the magnetoacoustic cyclotron instability of fusion-born ions in relation to ion cyclotron emission

    NASA Astrophysics Data System (ADS)

    Carbajal, L.; Dendy, R. O.; Chapman, S. C.; Cook, J. W. S.

    2014-01-01

    The magnetoacoustic cyclotron instability (MCI) probably underlies observations of ion cyclotron emission (ICE) from energetic ion populations in tokamak plasmas, including fusion-born alpha-particles in JET and TFTR [Dendy et al., Nucl. Fusion 35, 1733 (1995)]. ICE is a potential diagnostic for lost alpha-particles in ITER; furthermore, the MCI is representative of a class of collective instabilities, which may result in the partial channelling of the free energy of energetic ions into radiation, and away from collisional heating of the plasma. Deep understanding of the MCI is thus of substantial practical interest for fusion, and the hybrid approximation for the plasma, where ions are treated as particles and electrons as a neutralising massless fluid, offers an attractive way forward. The hybrid simulations presented here access MCI physics that arises on timescales longer than can be addressed by fully kinetic particle-in-cell simulations and by analytical linear theory, which the present simulations largely corroborate. Our results go further than previous studies by entering into the nonlinear stage of the MCI, which shows novel features. These include stronger drive at low cyclotron harmonics, the re-energisation of the alpha-particle population, self-modulation of the phase shift between the electrostatic and electromagnetic components, and coupling between low and high frequency modes of the excited electromagnetic field.

  16. Electrostatic ion-cyclotron waves in a nonuniform magnetic field

    NASA Technical Reports Server (NTRS)

    Cartier, S. L.; Dangelo, N.; Merlino, R. L.

    1985-01-01

    The properties of electrostatic ion-cyclotron waves excited in a single-ended cesium Q machine with a nonuniform magnetic field are described. The electrostatic ion-cyclotron waves are generated in the usual manner by drawing an electron current to a small exciter disk immersed in the plasma column. The parallel and perpendicular (to B) wavelengths and phase velocities are determined by mapping out two-dimensional wave phase contours. The wave frequency f depends on the location of the exciter disk in the nonuniform magnetic field, and propagating waves are only observed in the region where f is approximately greater than fci, where fci is the local ion-cyclotron frequency. The parallel phase velocity is in the direction of the electron drift. From measurements of the plasma properties along the axis, it is inferred that the electron drift velocity is not uniform along the entire current channel. The evidence suggests that the waves begin being excited at that axial position where the critical drift velocity is first exceeded, consistent with a current-driven excitation mechanism.

  17. Electromagnetic ion beam instabilities - Growth at cyclotron harmonic wave numbers

    NASA Technical Reports Server (NTRS)

    Smith, Charles W.; Gary, S. Peter

    1987-01-01

    The linear theory of electromagnetic ion beam instabilities for arbitrary angles of propagation is studied, with an emphasis on the conditions necessary to generate unstable modes at low harmonics of the ion cyclotron resonance condition. The present results extend the analysis of Smith et al. (1985). That paper considered only the plasma parameters at a time during which harmonic wave modes were observed in the earth's foreshock. The parameters of that paper are used as the basis of parametric variations here to establish the range of beam properties which may give rise to observable harmonic spectra. It is shown that the growth rates of both left-hand and right-hand cyclotron harmonic instabilities are enhanced by an increase in the beam temperature anisotropy and/or the beam speed. Decreases in the beam density and/or the core-ion beta reduce the overall growth of the cyclotron harmonic instabilities but favor the growth of these modes over the growth of the nonresonant instability and thereby enhance the observability of the harmonics.

  18. Analytic model of electromagnetic ion-cyclotron anisotropy instability

    SciTech Connect

    Yoon, P. H.; Seough, J. J.; Khim, K. K.; Kim, Hyunnam; Kwon, Hyuck-Jin; Park, Jongsun; Parkh, Sarah; Park, Kyung Sun

    2010-08-15

    In the present paper, the real frequency and growth rate associated with the electromagnetic ion cyclotron instability driven by temperature anisotropy are analytically modeled on the basis of conjecture and upon comparison with numerical roots of the dispersion relation. The ions are assumed to have an anisotropic distribution function with Maxwellian parallel distribution. Under such an assumption complex roots of the dispersion relation depend only on two dimensionless parameters, namely, the temperature anisotropy factor A=T{sub perpendiculari}/T{sub ||}i-1, where T{sub perpendiculari} and T{sub ||i} are the perpendicular and parallel ion temperatures, respectively, and the parallel ion beta, {beta}=(8{pi}nT{sub i}/B{sup 2}){sup 1/2}, where n and B are the plasma density and magnetic field intensity, respectively. The ion-cyclotron instability is thus heuristically modeled by complex frequency which is parametrically dependent on A and {beta}. The present result constitutes a useful shortcut research tool that may be employed in a wide variety of applications.

  19. Coupling of electrostatic ion cyclotron and ion acoustic waves in the solar wind

    NASA Astrophysics Data System (ADS)

    Sreeraj, T.; Singh, S. V.; Lakhina, G. S.

    2016-08-01

    The coupling of electrostatic ion cyclotron and ion acoustic waves is examined in three component magnetized plasma consisting of electrons, protons, and alpha particles. In the theoretical model relevant to solar wind plasma, electrons are assumed to be superthermal with kappa distribution and protons as well as alpha particles follow the fluid dynamical equations. A general linear dispersion relation is derived for such a plasma system which is analyzed both analytically and numerically. For parallel propagation, electrostatic ion cyclotron (proton and helium cyclotron) and ion acoustic (slow and fast) modes are decoupled. For oblique propagation, coupling between the cyclotron and acoustic modes occurs. Furthermore, when the angle of propagation is increased, the separation between acoustic and cyclotron modes increases which is an indication of weaker coupling at large angle of propagation. For perpendicular propagation, only cyclotron modes are observed. The effect of various parameters such as number density and temperature of alpha particles and superthermality on dispersion characteristics is examined in details. The coupling between various modes occurs for small values of wavenumber.

  20. Backward mode of the ion-cyclotron wave in a semi-bounded magnetized Lorentzian plasma

    SciTech Connect

    Ki, Dae-Han; Jung, Young-Dae

    2012-08-15

    The backward modes of the surface ion-cyclotron wave are investigated in a semi-bounded magnetized Lorentzian plasma. The dispersion relation of the backward mode of the surface ion-cyclotron wave is obtained using the specular reflection boundary condition with the plasma dielectric function. The result shows that the nonthermal effect suppresses the wave frequency as well as the group velocity of the surface ion-cyclotron wave. It is also found that the nonthermal effect on the surface ion-cyclotron wave increases with an increase of the wave number. In addition, it is found that the propagation domain of the surface ion-cyclotron wave increases with an increase of the ratio of the electron plasma frequency to the electron gyrofrequency. It is also found that the nonthermal effect increases the propagation domain of the surface ion-cyclotron wave in a semi-bounded magnetized Lorentzian plasma.

  1. Sawtooth control in ITER using ion cyclotron resonance heating

    SciTech Connect

    Chapman, I. T.; Graves, J P; Johnson, T.; Asunta, O.; Bonoli, P.; Choi, M.; Jaeger, E. F.; Jucker, M.; Sauter, O.

    2011-01-01

    Numerical modeling of the effects of ion cyclotron resonance heating (ICRH) on the stability of the internal kink mode suggests that ICRH should be considered as an essential sawtooth control tool in ITER. Sawtooth control using ICRH is achieved by directly affecting the energy of the internal kink mode rather than through modification of the magnetic shear by driving localized currents. Consequently, ICRH can be seen as complementary to the planned electron cyclotron current drive actuator, and indeed will improve the efficacy of current drive schemes. Simulations of the ICRH distribution using independent RF codes give confidence in numerical predictions that the stabilizing influence of the fusion-born alphas can be negated by appropriately tailored minority (3)He ICRH heating in ITER. Finally, the effectiveness of all sawtooth actuators is shown to increase as the q = 1 surface moves towards the manetic axis, whilst the passive stabilization arising from the alpha and NBI particles decreases.

  2. Observation of a high-confinement regime in a tokamak plasma with ion cyclotron resonance heating

    NASA Astrophysics Data System (ADS)

    Steinmetz, K.; Noterdaeme, J.-M.; Wagner, F.; Wesner, F.; Bäumler, J.; Becker, G.; Bosch, H. S.; Brambilla, M.; Braun, F.; Brocken, H.; Eberhagen, A.; Fritsch, R.; Fussmann, G.; Gehre, O.; Gernhardt, J.; v. Gierke, G.; Glock, E.; Gruber, O.; Haas, G.; Hofmann, J.; Hofmeister, F.; Izvozchikov, A.; Janeschitz, G.; Karger, F.; Keilhacker, M.; Klüber, O.; Kornherr, M.; Lackner, K.; Lisitano, G.; van Mark, E.; Mast, F.; Mayer, H. M.; McCormick, K.; Meisel, D.; Mertens, V.; Müller, E. R.; Murmann, H.; Niedermeyer, H.; Poschenrieder, W.; Puri, S.; Rapp, H.; Röhr, H.; Ryter, F.; Schmitter, K.-H.; Schneider, F.; Setzensack, C.; Siller, G.; Smeulders, P.; Söldner, F.; Speth, E.; Steuer, K.-H.; Vollmer, O.; Wedler, H.; Zasche, D.

    1987-01-01

    The H mode in ion cyclotron-resonance-heated plasmas has been investigated with and without additional neutral beam injection. Ion cyclotron-resonance heating can cause the transition into a high-confinement regime (H mode) in combination with beam heating. The H mode, however, has also been realized-for the first time-with ion cyclotron-resonance heating alone in the D (H)-hydrogen minority scheme at an absorbed rf power of 1.1 MW.

  3. Frequency-swept detector for ion cyclotron resonance mass spectrometers

    NASA Astrophysics Data System (ADS)

    Wronka, J.; Ridge, D. P.

    1982-04-01

    Design, construction, performance, and use of a frequency-swept bridge detector for ion cyclotron resonance mass spectrometry are described. Special features include characterization and simple automatic correction of phase shift to allow broadband detection. The result is a detection system that may be used either at constant field or constant frequency. Drift-mode operation is simplified in that it may be satisfactorily used without the various signal modulation schemes used in previous detectors. In the trapped mode the detector may be pulsed to control the timing of ion detection. This detector makes it possible to do frequency-swept double resonance experiments which provide spectra of all the product ions of a given reactant ion. Circuit schematics and typical frequency- and field-swept spectra are shown.

  4. Ion cyclotron resonance bridge detector for frequency sweep

    NASA Astrophysics Data System (ADS)

    Pitsakis, Michael N.; Wobschall, Darold C.

    1983-11-01

    An electronic ion cyclotron resonance detection system was designed and constructed. The ions are excited by sweeping the frequency of the electric field (3-300 kHz) using a sweep frequency generator with a nonlinear sweep voltage in order to maintain an approximately constant mass resolution. Ion detection is accomplished by a bridge with a phase-sensitive detector as a demodulator. The required reference signal for the phase-sensitive detector is generated by a circuit with a transfer function which approximates that of the ICR signal in order to obtain an accurate phase match between the signal source and the detector. The device is capable of detecting a minimum concentration of 50 ions/cm3 over a mass range of 15 to 1500 amu.

  5. Application of compact electron cyclotron resonance ion source

    SciTech Connect

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Ogawa, H.; Hojo, S.; Kubo, T.; Kato, Y.; Biri, S.; Fekete, E.; Yoshida, Y.; Drentje, A. G.

    2008-02-15

    The compact electron cyclotron resonance (ECR) ion source with a permanent magnet configuration (Kei2 source) has been developed at National Institute of Radiological Sciences for a new carbon therapy facility. The Kei2 source was designed for production of C{sup 4+} ions; its performance such as beam intensity and stability has already reached the medical requirements. Therefore, the prototype development of the source for medical use is essentially finished. Recently, we have started a few studies on other applications of the source. One is the production of fullerenes in the ECR plasma and modified fullerenes with various atoms for new materials. A second application is the production of multiply charged ions (not only carbon) for ion implantation. In this paper, some basic experiments for these applications are reported.

  6. Grating monochromator for electron cyclotron resonance ion source operation.

    PubMed

    Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shouichi; Watanabe, Shin-ichi; Oyaizu, Michihiro; Kubono, Shigeru; Yamaguchi, Hidetoshi; Kase, Masayuki; Hattori, Toshiyuki; Shimoura, Susumu

    2013-07-01

    Recently, we started to observe optical line spectra from an ECR plasma using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for beam tuning because it allows the extraction of the desired ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research gives new insights into its simplification. In this paper, the grating monochromator method for beam tuning of a Hyper-ECR ion source as an injector for RIKEN azimuthal varying field (AVF) cyclotron is described. PMID:23902055

  7. Glow plasma trigger for electron cyclotron resonance ion sources.

    PubMed

    Vodopianov, A V; Golubev, S V; Izotov, I V; Nikolaev, A G; Oks, E M; Savkin, K P; Yushkov, G Yu

    2010-02-01

    Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 micros and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10(12) cm(-3), required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T(e) approximately = 20 eV. PMID:20192326

  8. Glow plasma trigger for electron cyclotron resonance ion sources

    SciTech Connect

    Vodopianov, A. V.; Golubev, S. V.; Izotov, I. V.; Nikolaev, A. G.; Oks, E. M.; Savkin, K. P.; Yushkov, G. Yu.

    2010-02-15

    Electron cyclotron resonance ion sources (ECRISs) are particularly useful for nuclear, atomic, and high energy physics, as unique high current generators of multicharged ion beams. Plasmas of gas discharges in an open magnetic trap heated by pulsed (100 {mu}s and longer) high power (100 kW and higher) high-frequency (greater than 37.5 GHz) microwaves of gyrotrons is promising in the field of research in the development of electron cyclotron resonance sources for high charge state ion beams. Reaching high ion charge states requires a decrease in gas pressure in the magnetic trap, but this method leads to increases in time, in which the microwave discharge develops. The gas breakdown and microwave discharge duration becomes greater than or equal to the microwave pulse duration when the pressure is decreased. This makes reaching the critical plasma density initiate an electron cyclotron resonance (ECR) discharge during pulse of microwave gyrotron radiation with gas pressure lower than a certain threshold. In order to reduce losses of microwave power, it is necessary to shorten the time of development of the ECR discharge. For fast triggering of ECR discharge under low pressure in an ECRIS, we initially propose to fill the magnetic trap with the plasmas of auxiliary pulsed discharges in crossed ExB fields. The glow plasma trigger of ECR based on a Penning or magnetron discharge has made it possible not only to fill the trap with plasma with density of 10{sup 12} cm{sup -3}, required for a rapid increase in plasma density and finally for ECR discharge ignition, but also to initially heat the plasma electrons to T{sub e}{approx_equal}20 eV.

  9. Effects of energetic heavy ions on electromagnetic ion cyclotron wave generation in the plasmapause region

    NASA Technical Reports Server (NTRS)

    Kozyra, J. U.; Cravens, T. E.; Nagy, A. F.; Fontheim, E. G.; Ong, R. S. B.

    1984-01-01

    An expression for electromagnetic ion cyclotron convective growth rates is derived. The derivation of the dispersion relation and convective growth rates in the presence of a multicomponent energetic and cold plasma is presented. The effects that multiple heavy ions in the ring current and cold plasma produce in the growth and propagation characteristics of ion cyclotron waves are explored. Results of growth rate calculations using parameters consistent with conditions in the plasmapause region during the early recovery phase of geomagnetic storms are presented and compared with ground-based and satellite observations of waves in this region. The geophysical implications of the results are discussed.

  10. A new ion and electron detector for ion cyclotron resonance spectroscopy.

    NASA Technical Reports Server (NTRS)

    Huntress, W. T., Jr.; Simms, W. T.

    1973-01-01

    A new detector using an extremelly driven tuned circuit has been developed for use in ion cyclotron resonance spectroscopy experiments. Based on the Q-meter circuit, this detector will operate at frequencies greater than 1 MHz at rf levels less than 1 mV. Operation in the frequency range 1-15 MHz allows the use of higher magnetic fields for more efficient storage of low mass ions in the trapping mode of operation. In the frequency range 2-6 MHz electrons can be detected in the ion cyclotron resonance cell by their resonant motion in the trapping plane.

  11. Ion beam driven resonant ion-cyclotron instability in a magnetized dusty plasma

    SciTech Connect

    Prakash, Ved; Vijayshri; Sharma, Suresh C.; Gupta, Ruby

    2014-03-15

    Electrostatic ion cyclotron waves are excited by axial ion beam in a dusty plasma via Cerenkov and slow cyclotron interaction. The dispersion relation of the instability is derived in the presence of positively/negatively charged dust grains. The minimum beam velocity needed for the excitation is estimated for different values of relative density of negatively charged dust grains. It is shown that the minimum beam velocity needed for excitation increases as the charge density carried by dust increases. Temperature of electrons and ions, charge and mass of dust grains, external static magnetic field and finite boundary of dusty plasma significantly modify the dispersion properties of these waves and play a crucial role in the growth of resonant ion cyclotron instability. The ion cyclotron modes with phase velocity comparable to the beam velocity possess a large growth rate. The maximum value of growth rate increases with the beam density and scales as the one-third power of the beam density in Cerenkov interaction and is proportional to the square root of beam density in slow cyclotron interaction.

  12. Ion cyclotron range of frequency heating of a deuterium-tritium plasma via the second-harmonic tritium cyclotron resonance

    SciTech Connect

    Wilson, J.R.; Bush, C.E.; Darrow, D.; Hosea, J.C.; Jaeger, E.F.; Majeski, R.; Murakami, M.; Phillips, C.K.; Rogers, J.H.; Schilling, G.; Stevens, J.E.; Synakowski, E.; Taylor, G.

    1995-07-31

    Experiments have been performed on the TFTR to study rf wave heating of a D-T plasma by way of the second-harmonic tritium cyclotron resonance. The addition of tritium ions to a deuterium plasma allows for absorption of the rf waves at the tritium cyclotron harmonics and by electron damping of a mode converted ion Bernstein wave. Competing mechanisms include direct electron damping and damping at the fundamental cyclotron resonance of deuterium, {alpha} particles, and {sup 3}He ions. The contribution of each is estimated from a series of plasma discharges where various plasma parameters are varied. The majority of the rf power is found to damp on the tritium ions.

  13. Electrostatic ion cyclotron and ion plasma waves in a symmetric pair-ion plasma cylinder.

    PubMed

    Kono, M; Vranjes, J; Batool, N

    2014-03-14

    Complicated wave behavior observed in the cylindrical pair-ion (fullerene) experiments by Oohara and co-workers are now identified to be low harmonic ion cyclotron waves combined with ion plasma oscillations inherent to kinetic theory. The electrostatic dispersion equation derived is based on an approximation for the current from the exact solutions of the characteristic cylindrical geometry form of the Vlasov plasma equation in a uniform magnetized plasma cylinder surrounded by a larger metal boundary outside a vacuum gap, which thus differs from that in unbounded plasmas. Positive and negative ions, differing only in the sign of their charge, respond to a potential in the same time scale and cooperate to reflect the enhanced kinetic orbital behaviors to the macroscopic propagation characteristics. In addition, the experimental value of the Larmor radius (comparable to the discharge radius but small enough to make the analytic approximation useful) makes higher harmonic ion cyclotron effects both observable and calculable with the appropriate approximation for the kinetic theory. PMID:24679299

  14. Pulsed magnetic field-electron cyclotron resonance ion source operation

    SciTech Connect

    Muehle, C.; Ratzinger, U.; Joest, G.; Leible, K.; Schennach, S.; Wolf, B.H.

    1996-03-01

    The pulsed magnetic field (PuMa)-electron cyclotron resonance (ECR) ion source uses a pulsed coil to improve the peak current by opening the magnetic bottle along the beam axis. After demonstration of the principle of the pulsed magnetic extraction, the ion source was tested with different gases. We received promising results from helium to krypton. The influence of the current in the pulsed coil on the analyzed ion current was measured. With increased current levels within the pulsed coil not only the pulse height of the PuMa pulse, but the pulse length can also be controlled. By using the pulsed coil the maximum of the charge state distribution can be shifted to higher charge states. {copyright} {ital 1996 American Institute of Physics.}

  15. Electromagnetic ion cyclotron waves in the plasma depletion layer

    NASA Technical Reports Server (NTRS)

    Denton, Richard E.; Hudson, Mary K.; Fuselier, Stephen A.; Anderson, Brian J.

    1993-01-01

    Results of a study of the theoretical properties of electromagnetic ion cyclotron (EMIC) waves which occur in the plasma depletion layer are presented. The analysis assumes a homogeneous plasma with the characteristics which were measured by the AMPTE/CCE satellite at 1450-1501 UT on October 5, 1984. Waves were observed in the Pc 1 frequency range below the hydrogen gyrofrequency, and these waves are identified as EMIC waves. The higher-frequency instability is driven by the temperature anisotropy of the H(+) ions, while the lower-frequency instability is driven by the temperature anisotropy of the He(2+) ions. It is argued that the higher-frequency waves will have k roughly parallel to B(0) and will be left-hand polarized, while the lower frequency wave band will have k oblique to B(0) and will be linearly polarized, in agreement with observations.

  16. Frequency-scanning marginal oscillator for ion cyclotron resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Kemper, Paul R.; Bowers, Michael T.

    1982-07-01

    A number of ion cyclotron resonance applications have arisen in the past few years which require a frequency-scanned detection system. Since the traditional marginal oscillator detector has always been a fixed-frequency detector, alternative detection techniques such as bridge circuit detectors have become widely used. In this paper we present an alternative to the bridge detector, namely, a frequency-scanning marginal oscillator. Requirements and modifications necessary to convert a marginal oscillator to frequency scanning operation are discussed in detail and the necessary circuit diagrams presented. Finally, a theoretical comparison is made between bridge circuit and marginal oscillator sensitivities.

  17. Electron cyclotron resonance microwave ion sources for thin film processing

    SciTech Connect

    Berry, L.A.; Gorbatkin, S.M.

    1990-01-01

    Plasmas created by microwave absorption at the electron cyclotron resonance (ECR) are increasingly used for a variety of plasma processes, including both etching and deposition. ECR sources efficiently couple energy to electrons and use magnetic confinement to maximize the probability of an electron creating an ion or free radical in pressure regimes where the mean free path for ionization is comparable to the ECR source dimensions. The general operating principles of ECR sources are discussed with special emphasis on their use for thin film etching. Data on source performance during Cl base etching of Si using an ECR system are presented. 32 refs., 5 figs.

  18. Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

    NASA Technical Reports Server (NTRS)

    Persoon, A. M.; Peterson, W. K.; Andre, M.; Chang, T.; Gurnett, D. A.; Retterer, J. M.; Crew, G. B.

    1997-01-01

    Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low- frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies.

  19. Multi-Species Test of Ion Cyclotron Resonance Heating at High Altitudes

    NASA Technical Reports Server (NTRS)

    Persoon, A. M.; Peterson, W. K.; Andre, M.; Chang, T.; Gurnett, D. A.; Retterer, J. M.; Crew, G. B.

    1997-01-01

    Observations of ion distributions and plasma waves obtained by the Dynamics Explorer 1 satellite in the high-altitude, nightside auroral zone are used to study ion energization for three ion species. A number of theoretical models have been proposed to account for the transverse heating of these ion populations. One of these, the ion cyclotron resonance heating (ICRH) mechanism, explains ion conic formation through ion cyclotron resonance with broadband electromagnetic wave turbulence in the vicinity of the characteristic ion cyclotron frequency. The cyclotron resonant heating of the ions by low-frequency electromagnetic waves is an important energy source for the transport of ions from the ionosphere to the magnetosphere. In this paper we test the applicability of the ICRH mechanism to three simultaneously heated and accelerated ion species by modelling the ion conic formation in terms of a resonant wave-particle interaction in which the ions extract energy from the portion of the broadband electromagnetic wave spectrum which includes the ion cyclotron frequency. Using a Monte Carlo technique we evaluate the ion heating produced by the electromagnetic turbulence at low frequencies and find that the wave amplitudes near the ion cyclotron frequencies are sufficient to explain the observed ion energies.

  20. Collisional electrostatic ion cyclotron waves as a possible source of energetic heavy ions in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Providakes, Jason; Seyler, Charles E.

    1990-01-01

    A new mechanism is proposed for the source of energetic heavy ions (NO/+/, O2/+/, and O/+/) found in the magnetosphere. Simulations using a multispecies particle simulation code for resistive current-driven electrostatic ion cyclotron waves show transverse and parallel bulk heating of bottomside ionospheric heavy ion populations. The dominant mechanism for the transverse bulk heating is resonant ion heating by wave-particle ion trapping. Using a linear kinetic dispersion relation for a magnetized, collisional, homogenous, and multiion plasma, it is found that collisional electrostatic ion cyclotron waves near the NO(+), O2(+), and O(+) gyrofrequencies are unstable to field-aligned currents of 50 microA/sq m for a typical bottomside ionosphere.

  1. The negative hydrogen Penning ion gauge ion source for KIRAMS-13 cyclotron

    SciTech Connect

    An, D. H.; Jung, I. S.; Kang, J.; Chang, H. S.; Hong, B. H.; Hong, S.; Lee, M. Y.; Kim, Y.; Yang, T. K.; Chai, J. S.

    2008-02-15

    The cold-cathode-type Penning ion gauge (PIG) ion source for the internal ion source of KIRAMS-13 cyclotron has been used for generation of negative hydrogen ions. The dc H-beam current of 650 {mu}A from the PIG ion source with the Dee voltage of 40 kV and arc current of 1.0 A is extrapolated from the measured dc extraction beam currents at the low extraction dc voltages. The output optimization of PIG ion source in the cyclotron has been carried out by using various chimneys with different sizes of the expansion gap between the plasma boundary and the chimney wall. This paper presents the results of the dc H-extraction measurement and the expansion gap experiment.

  2. An ion cyclotron resonance study of reactions of some atomic and simple polyatomic ions with water

    NASA Technical Reports Server (NTRS)

    Karpas, Z.; Anicich, V. G.; Huntress, W. T., Jr.

    1978-01-01

    Reactions of various positive ions with water vapor were studied by ion cyclotron resonance mass spectrometric techniques. Rate constants and product distributions were determined for reactions of the ions: Ar(+), Co(+), N2(+), and CO2(+), CH2(+), and CH4(+), CH2Cl(+), HCO(+), H2CO(+), H2COH(+), H2S(+) and HS(+). The results obtained in this work are compared with earlier reported data where available.

  3. Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

    SciTech Connect

    Jeong, S. C.; Oyaizu, M.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Niki, K.; Okada, M.; Watanabe, Y. X.; Otokawa, Y.; Osa, A.; Ichikawa, S.

    2012-02-15

    We investigated the ion-loss distribution on the sidewall of an electron cyclotron resonance (ECR) plasma chamber using the 18-GHz ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex (TRIAC). Similarities and differences between the ion-loss distributions (longitudinal and azimuthal) of different ion species (i.e., radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions that are typical volatile and nonvolatile elements) was qualitatively discussed to understand the element dependence of the charge breeding efficiency. Especially, the similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.

  4. Sawtooth-Control Mechanism using Toroidally Propagating Ion-Cyclotron-Resonance Waves in Tokamaks

    SciTech Connect

    Graves, J. P.; Coda, S.; Chapman, I.

    2009-02-13

    The sawtooth control mechanism in plasmas employing off-axis toroidally propagating ion cyclotron resonance waves in tokamaks is reinvestigated. The radial drift excursion of energetic passing ions distributed asymmetrically in the velocity parallel to the magnetic field determines stability when the rational q=1 surface resides within a narrow region centered about the shifted fundamental cyclotron resonance.

  5. Ion-cyclotron turbulence and diagonal double layers in a magnetospheric plasma

    NASA Technical Reports Server (NTRS)

    Liperovskiy, V. A.; Pudovkin, M. I.; Skuridin, G. A.; Shalimov, S. L.

    1981-01-01

    A survey of current concepts regarding electrostatic ion-cyclotron turbulence (theory and experiment), and regarding inclined double potential layers in the magnetospheric plasma is presented. Anomalous resistance governed by electrostatic ion-cyclotron turbulence, and one-dimensional and two-dimensional models of double electrostatic layers in the magnetospheric plasma are examined.

  6. Excitation of low frequency waves by streaming ions via anomalous cyclotron resonance

    NASA Technical Reports Server (NTRS)

    Wu, C. S.; Dillenburg, D.; Gaffey, J. D., Jr.; Ziebell, L. F.; Goedert, J.; Freund, H. P.

    1978-01-01

    The effect of a small population of streaming ions on low-frequency waves with frequencies below the ion cyclotron frequency is analyzed for three modes of interest: Alfven waves, magnetosonic waves, and ion-cyclotron waves. The instability mechanism is the anomalous cyclotron resonance of the waves with the streaming ions. Conditions for excitation of the three types of waves are derived and expressions for the growth rates are obtained. Excitation of Alfven waves is possible even if the ratio of the densities of the streaming ions to the thermal ions is very small. For magnetosonic waves, excitation can easily occur if waves are propagating parallel or nearly parallel to the ambient magnetic field. As for ion-cyclotron waves, it is found that for the ion-whistler branch the excitation is suppressed over a broader range of wave frequencies than for the fast magnetosonic branch.

  7. Dynamic regimes of cyclotron instability in the afterglow mode of minimum-B electron cyclotron resonance ion source plasma

    NASA Astrophysics Data System (ADS)

    Mansfeld, D.; Izotov, I.; Skalyga, V.; Tarvainen, O.; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.

    2016-04-01

    The paper is concerned with the dynamic regimes of cyclotron instabilities in non-equilibrium plasma of a minimum-B electron cyclotron resonance ion source operated in pulsed mode. The instability appears in decaying ion source plasma shortly (1-10 ms) after switching off the microwave radiation of the klystron, and manifests itself in the form of powerful pulses of electromagnetic emission associated with precipitation of high-energy electrons along the magnetic field lines. Recently it was shown that this plasma instability causes perturbations of the extracted ion current, which limits the performance of the ion source and generates strong bursts of bremsstrahlung emission. In this article we present time-resolved diagnostics of electromagnetic emission bursts related to cyclotron instability in the decaying plasma. The temporal resolution is sufficient to study the fine structure of the dynamic spectra of the electromagnetic emission at different operating regimes of the ion source. It was found that at different values of magnetic field and heating power the dynamic spectra demonstrate common features: Decreasing frequency from burst to burst and an always falling tone during a single burst of instability. The analysis has shown that the instability is driven by the resonant interaction of hot electrons, distributed between the electron cyclotron resonance (ECR) zone and the trap center, with slow extraordinary wave propagation quasi-parallel with respect to the external magnetic field.

  8. Research and development of ion surfing RF carpets for the cyclotron gas stopper at the NSCL

    NASA Astrophysics Data System (ADS)

    Gehring, A. E.; Brodeur, M.; Bollen, G.; Morrissey, D. J.; Schwarz, S.

    2016-06-01

    A model device to transport thermal ions in the cyclotron gas stopper, a next-generation beam thermalization device under construction at the National Superconducting Cyclotron Laboratory, is presented. Radioactive ions produced by projectile fragmentation will come to rest at distances as large as 45 cm from the extraction orifice of the cyclotron gas stopper. The thermalized ions will be transported to the exit by RF carpets employing the recently developed "ion surfing" method. A quarter-circle prototype RF carpet was tested with potassium ions, and ion transport velocities as high as 60 m/s were observed over distances greater than 10 cm at a helium buffer gas pressure of 80 mbar. The transport of rubidium ions from an RF carpet to an electrode below was also demonstrated. The results of this study formed the basis of the design of the RF carpets for use in the cyclotron gas stopper.

  9. Parallel Spectral Acquisition with an Ion Cyclotron Resonance Cell Array.

    PubMed

    Park, Sung-Gun; Anderson, Gordon A; Navare, Arti T; Bruce, James E

    2016-01-19

    Mass measurement accuracy is a critical analytical figure-of-merit in most areas of mass spectrometry application. However, the time required for acquisition of high-resolution, high mass accuracy data limits many applications and is an aspect under continual pressure for development. Current efforts target implementation of higher electrostatic and magnetic fields because ion oscillatory frequencies increase linearly with field strength. As such, the time required for spectral acquisition of a given resolving power and mass accuracy decreases linearly with increasing fields. Mass spectrometer developments to include multiple high-resolution detectors that can be operated in parallel could further decrease the acquisition time by a factor of n, the number of detectors. Efforts described here resulted in development of an instrument with a set of Fourier transform ion cyclotron resonance (ICR) cells as detectors that constitute the first MS array capable of parallel high-resolution spectral acquisition. ICR cell array systems consisting of three or five cells were constructed with printed circuit boards and installed within a single superconducting magnet and vacuum system. Independent ion populations were injected and trapped within each cell in the array. Upon filling the array, all ions in all cells were simultaneously excited and ICR signals from each cell were independently amplified and recorded in parallel. Presented here are the initial results of successful parallel spectral acquisition, parallel mass spectrometry (MS) and MS/MS measurements, and parallel high-resolution acquisition with the MS array system. PMID:26669509

  10. A new mechanism for excitation of electrostatic ion cyclotron waves and associated perpendicular ion heating

    NASA Technical Reports Server (NTRS)

    Ganguli, G.; Lee, Y. C.; Palmadesso, P.

    1985-01-01

    A new mechanism for exciting the kinetic ion cyclotron waves in the presence of a nonuniform electric field perpendicular to the external magnetic field is given. Application of this instability to various space plasmas is discussed. The new instability mechanism may provide a more efficient agent for perpendicular ion heating than other EIC generation processes, since the linear growth rate is insensitive to the temperature ratio.

  11. Transport induced by ion cyclotron range of frequencies waves

    SciTech Connect

    Zhang, Debing Xu, Yingfeng; Wang, Shaojie

    2014-11-15

    The Vlasov equation, which includes the effect of the ion cyclotron range of frequencies (ICRF) waves, can be written as the Fokker-Planck equation which describes the quasilinear transport in phase space by using the Lie-transform method. The radial transport fluxes of particle, energy and parallel momentum driven by ICRF waves in the slab geometry have been derived. The results show that the ICRF-induced radial redistributions of particle, energy and parallel momentum are driven by the inhomogeneity in energy of the equilibrium distribution function, and related to the correlation between the excursion in the real space and the excursion in energy. For the case with strong asymmetry of k{sub y} spectrum, the ICRF-induced radial transport driven by the energy inhomogeneity dominates the ICRF-induced radial transport driven by the spatial inhomogeneity.

  12. The technology of the ion cyclotron range of frequencies

    SciTech Connect

    Hoffman, D.J.; Barber, G.C.

    1988-01-01

    Plasma heating in the ion cyclotron range of frequencies (ICRF) is the least expensive means of accomplishing auxiliary heating in fusion experiments. RF systems comprise two major elements: the transmitter and the antenna. The state of the art for the transmitter is already at the megawatt level. The technology of the antenna is strongly coupled to the plasma character. Typically, these antennas are designed to operate at a high power density (1.2 kW/cm/sup 2/) with an efficiency of 96%. ICRF technology and options have improved over the past few years, owing to development and experiments; however, the optimal combination of options can be defined only when results from confinement experiments and test facilities are in hand. 19 refs., 5 figs., 1 tab.

  13. Resonance of relativistic electrons with electromagnetic ion cyclotron waves

    DOE PAGESBeta

    Denton, R. E.; Jordanova, V. K.; Bortnik, J.

    2015-06-29

    Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron EMIC waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motionmore » of the hot ring current protons that drive the instability. High density due to a plasmasphere or plasmaspheric plume could possibly lead to lower minimum resonance energy by causing the He band EMIC mode to be dominant. We demonstrate these points using parameters from a ring current simulation.« less

  14. Electromagnetic ion cyclotron waves stimulated by modest magnetospheric compressions

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Hamilton, D. C.

    1993-01-01

    AMPTE/CCE magnetic field and particle data are used to test the suggestion that increased hot proton temperature anisotropy resulting from convection during magnetospheric compression is responsible for the enhancement in Pc 1 emission via generation of electromagnetic ion cyclotron (EMIC) waves in the dayside outer equatorial magnetosphere. The relative increase in magnetic field is used to gauge the strength of the compression, and an image dipole model is used to estimate the motion of the plasma during compression. Proton data are used to analyze the evolution of the proton distribution and the corresponding changes in EMIC wave activity expected during the compression. It is suggested that enhancements in dynamic pressure pump the energetic proton distributions in the outer magnetosphere, driving EMIC waves. Waves are expected to be generated most readily close to the magnetopause, and transient pressure pulses may be associated with bursts of EMIC waves, which would be observed on the ground in association with ionospheric transient signatures.

  15. Electromagnetic ion cyclotron waves observed in the plasma depletion layer

    NASA Technical Reports Server (NTRS)

    Anderson, B. J.; Fuselier, S. A.; Murr, D.

    1991-01-01

    Observations from AMPTE/CCE in the earth's magnetosheath on October 5, 1984 are presented to illustrate 0.1 - 4.0 Hz magnetic field pulsations in the subsolar plasma depletion layer (PDL) for northward sheath field during a magnetospheric compression. The PDL is unambiguously identified by comparing CCE data with data from IRM in the upstream solar wind. Pulsations in the PDL are dominated by transverse waves with F/F(H+) 1.0 or less and a slot in spectral power at F/F(H+) = 0.5. The upper branch is left hand polarized while the lower branch is linearly polarized. In the sheath the proton temperature anisotropy is about 0.6 but it is about 1.7 in the PDL during wave occurrence. The properties and correlation of waves with increased anisotropy indicate that they are electromagnetic ion cyclotron waves.

  16. Resonance of relativistic electrons with electromagnetic ion cyclotron waves

    SciTech Connect

    Denton, R. E.; Jordanova, V. K.; Bortnik, J.

    2015-06-29

    Relativistic electrons have been thought to more easily resonate with electromagnetic ion cyclotron EMIC waves if the total density is large. We show that, for a particular EMIC mode, this dependence is weak due to the dependence of the wave frequency and wave vector on the density. A significant increase in relativistic electron minimum resonant energy might occur for the H band EMIC mode only for small density, but no changes in parameters significantly decrease the minimum resonant energy from a nominal value. The minimum resonant energy depends most strongly on the thermal velocity associated with the field line motion of the hot ring current protons that drive the instability. High density due to a plasmasphere or plasmaspheric plume could possibly lead to lower minimum resonance energy by causing the He band EMIC mode to be dominant. We demonstrate these points using parameters from a ring current simulation.

  17. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron

    NASA Astrophysics Data System (ADS)

    Hojo, S.; Katagiri, K.; Nakao, M.; Sugiura, A.; Muramatsu, M.; Noda, A.; Okada, T.; Takahashi, Y.; Komiyama, A.; Honma, T.; Noda, K.

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C4+ ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C4+, for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

  18. Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron.

    PubMed

    Hojo, S; Katagiri, K; Nakao, M; Sugiura, A; Muramatsu, M; Noda, A; Okada, T; Takahashi, Y; Komiyama, A; Honma, T; Noda, K

    2014-02-01

    The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C(4+) ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 μA for proton and deuteron, 50 μA for C(4+), for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source. PMID:24593538

  19. Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source

    SciTech Connect

    Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O.; Tamura, M.; Aihara, T.; Uchiyama, A.

    2012-02-15

    A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U{sup 35+} for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.

  20. Development of an 18 GHz superconducting electron cyclotron resonance ion source at RCNP.

    PubMed

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2008-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has recently been developed and installed in order to extend the variety and the intensity of ions at the RCNP coupled cyclotron facility. Production of several ions such as O, N, Ar, Kr, etc., is now under development and some of them have already been used for user experiments. For example, highly charged heavy ion beams like (86)Kr(21+,23+) and intense (16)O(5+,6+) and (15)N(6+) ion beams have been provided for experiments. The metal ion from volatile compounds method for boron ions has been developed as well. PMID:18315101

  1. Incorporation of a Flared Inlet Capillary Tube on a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer.

    SciTech Connect

    Wu, Si; Zhang, Kai; Kaiser, Nathan K.; Bruce, James E.; Prior, David C.; Anderson, Gordon A.

    2006-04-17

    Atmospheric pressure ion sources such as electrospray ionization (ESI) and atmospheric pressure matrix assisted laser desorption ionization (AP-MALDI) are widely used with mass spectrometry for proteomics studies. Other newly developed atmospheric ion sources include desorption electrospray ionization (DESI). For these ionization methods, analyte ions created at atmospheric pressure are transferred to the high vacuum region for mass analysis after several stages of differential pumping. It has been reported that overall charge transmission between the ion source and the first vacuum stage is primarily dependent upon the proximity of the emitter and gas conductance of the interface inlet. We therefore developed an atmospheric pressure interface using flared inlet tubes. This report highlights our results obtained by coupling the customized flared inlet tubes with a Fourier transfer ion cyclotron resonance mass spectrometer (FT-ICRMS). We have also investigated the new interface with different types of atmospheric pressure ionization methods. For most of the ionization methods we investigated, such as ESI and DESI, increased ion current transmitted from the atmospheric pressure ion source to the first stage vacuum system was observed with the use of our enhanced ion inlet designs. The ion intensity that was detected with the flared inlet tube on a FT-ICRMS was also observed to increase {approx} 2-5 fold using ESI or DESI with the flared tube inlet. Moreover, increased spray tip positional tolerance was observed with implementation of the flared inlet tube. We also include our preliminary results obtained by coupling APMALDI with flared inlet tube in this paper. For AP-MALDI, the measured ion current transferred through the flared inlet tube was about 3 times larger than the ion current through the control non-flared inlet tube.

  2. Means for obtaining a metal ion beam from a heavy-ion cyclotron source

    DOEpatents

    Hudson, E.D.; Mallory, M.L.

    1975-08-01

    A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

  3. HIGH FREQUENCY POWER TRANSMISSION LINE FOR CYCLOTRONS AND THE LIKE

    DOEpatents

    Armstrong, W.J.

    1954-04-20

    High-frequency power transmission systems, particularly a stacked capacitance alternating power current transmission line wherein maximum utilization of the effective conductios skin of the line conductors is achieved while enabling a low impedance to be obtained are reported. The transmission line consists of a number of flat metal strips with interleaved dielectric strips. The metal dielectric strips are coiled spirally with the axis of the spiral extending along the length of the strips, and the alternating metal strips at the output end have outwardly extending aligned lugs which are directly strapped together and connected to the respective terminals on the load. At the input end of the transmission line, similarly, the alternate metal strips are directly strapped together and connected to an altereating current source. With the arrangement described each metal strip conducts on both sides, so that the metal strips are designed to have a thickness corresponding to twice the depth of the "skin effect" conducting lamina of each conductor at the source frequency.

  4. Emission of ion and electron cyclotron harmonic radiation from mode conversion layers

    SciTech Connect

    Swanson, D.G.; Cho, S. )

    1989-07-01

    The asymmetry of cyclotron radiation from a mode conversion layer is presented for harmonics of the ion cyclotron frequency and the second harmonic of the electron cyclotron frequency for weakly relativistic electrons. The same form of Kirchhoff's law is found for all cases, relating the emission along each branch to the absorption of an incident wave along the corresponding branch. Results show that the fast wave radiation is more strongly asymmetric at the third harmonic than at the second harmonic of the ion cyclotron frequency, while the slow wave radiation ratio is about same. At the second cyclotron harmonic of weakly relativistic electrons, the asymmetry of radiation is found to be small at high temperature. The effect of equilibrium Bernstein wave radiation is also discussed.

  5. Emission of ion and electron cyclotron harmonic radiation from mode conversion layers

    SciTech Connect

    Cho, S.; Swanson, D.G. )

    1990-02-01

    The asymmetry of cyclotron radiation from a mode conversion layer is presented for harmonics of the ion cyclotron frequency and the second harmonic of the electron cyclotron frequency for weakly relativistic electrons. The same form of Kirchhoff's law is found for all cases, relating the emission along each branch to the absorption of an incident wave along the corresponding branch. Results show that the fast wave radiation is more strongly asymmetric at the third harmonic than at the second harmonic of the ion cyclotron frequency, while the slow wave radiation ratio is about same. At the second cyclotron harmonic of weakly relativistic electrons, the asymmetry of radiation is found to be small at high temperature. The effect of equilibrium Bernstein wave radiation is also discussed.

  6. ECR (electron cyclotron resonance) ion sources and applications with heavy-ion linacs

    SciTech Connect

    Pardo, R.C.

    1990-01-01

    The electron cyclotron resonance (ECR) ion source has been developed in the last few years into a reliable source of high charge-state heavy ions. The availability of heavy ions with relatively large charge-to-mass ratios (0.1--0.5) has made it possible to contemplate essentially new classes of heavy-ion linear accelerators. In this talk, I shall review the state-of-the-art in ECR source performance and describe some of the implications this performance level has for heavy-ion linear accelerator design. The present linear accelerator projects using ECR ion sources will be noted and the performance requirements of the ECR source for these projects will be reviewed. 30 refs., 3 figs.

  7. Plasma spectroscopy of metal ions for hyper-electron cyclotron resonance ion source.

    PubMed

    Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shoichi; Watanabe, Shin-ichi; Oyaizu, Michihiro; Kubono, Shigeru; Yamaguchi, Hidetoshi; Kase, Masayuki; Hattori, Toshiyuki; Shimoura, Susumu

    2014-02-01

    In this research, the optical line spectra of metal ions from ECR plasma were observed using a grating monochromator with a photomultiplier. The light intensity of line spectrum from the ECR plasma had a strong correlation with ion beam intensity measured by a magnetic mass analyzer. This correlation is a significant information for the beam tuning process, because it allows to conduct the extraction of the desired metal ion species from the ECR plasma. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process, but this research provides a new approach for its simplification. In this paper the grating monochromator method for metal ion beam tuning such as (40)Ca(12+), (56)Fe(15+), and (85)Rb(20+) of hyper-ECR ion source as an injector for RIKEN Azimuthal Varying Field cyclotron is described. PMID:24593484

  8. Ring Current-Electromagnetic Ion Cyclotron Waves Coupling

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.

    2005-01-01

    The effect of Electromagnetic Ion Cyclotron (EMIC) waves, generated by ion temperature anisotropy in Earth s ring current (RC), is the best known example of wave- particle interaction in the magnetosphere. Also, there is much controversy over the importance of EMIC waves on RC depletion. Under certain conditions, relativistic electrons, with energies 21 MeV, can be removed from the outer radiation belt (RB) by EMIC wave scattering during a magnetic storm. That is why the calculation of EMIC waves must be a very critical part of the space weather studies. The new RC model that we have developed and present for the first time has several new features that we have combine together in a one single model: (a) several lower frequency cold plasma wave modes are taken into account; (b) wave tracing of these wave has been incorporated in the energy EMIC wave equation; (c) no assumptions regarding wave shape spectra have been made; (d) no assumptions regarding the shape of particle distribution have been made to calculate the growth rate; (e) pitch-angle, energy, and mix diffusions are taken into account together for the first time; (f) the exact loss-cone RC analytical solution has been found and coupled with bounce-averaged numerical solution of kinetic equation; (g) the EMIC waves saturation due to their modulation instability and LHW generation are included as an additional factor that contributes to this process; and (h) the hot ions were included in the real part of dielectric permittivity tensor. We compare our theoretical results with the different EMIC waves models as well as RC experimental data.

  9. Experiments on ion cyclotron damping at the deuterium fourth harmonic in DIII-D

    SciTech Connect

    Pinsker, R.I.; Petty, C.C.; Baity, F.W.; Bernabei, S.; Greenough, N.; Heidbrink, W.W.; Mau, T.K.; Porkolab, M.

    1999-05-01

    Absorption of fast Alfven waves by the energetic ions of an injected beam is evaluated in the DIII-D tokamak. Ion cyclotron resonance absorption at the fourth harmonic of the deuteron cyclotron frequency is observed with deuterium neutral beam injection (f = 60 MHz, B{sub T} = 1.9 T). Enhanced D-D neutron rates are evidence of absorption at the Doppler-shifted cyclotron resonance. Characteristics of global energy confinement provide further proof of substantial beam acceleration by the rf. In many cases, the accelerated deuterons cause temporary stabilization of the sawtooth (monster sawteeth), at relatively low rf power levels of {approximately}1 MW.

  10. Comments on finite Larmor radius models for ion cyclotron range of frequencies heating in tokamaks

    SciTech Connect

    Phillips, C.K.; Wilson, J.R.; Hosea, J.C.; Majeski, R. ); Smithe, D.N. )

    1994-12-01

    The accuracy of standard finite Larmor radius (FLR) models for wave propagation in the ion cyclotron range of frequencies (ICRF) is compared against full hot plasma models. For multiple ion species plasmas, the FLR model is shown to predict the presence of a spurious second harmonic ion--ion type resonance between the second harmonic cyclotron layers of two ion species. It is shown explicitly here that the spurious resonance is an artifact of the FLR models and that no absorption occurs in the plasma as a result of this resonance.''

  11. Comments on finite Larmor radius models for ion cyclotron range of frequencies heating in tokamaks

    SciTech Connect

    Phillips, C.K.; Wilson, J.R.; Hosea, J.C.; Majeski, R.; Smithe, D.N.

    1994-06-01

    The accuracy of standard finite Larmor radius (FLR) models for wave propagation in the ion cyclotron range of frequencies (ICRF) is compared against full hot plasma models. For multiple ion species plasmas, the FLR model is shown to predict the presence of a spurious second harmonic ion-ion type resonance between the second harmonic cyclotron layers of two ion species. It is shown explicitly here that the spurious resonance is an artifact of the FLR models and that no absorption occurs in the plasma as a result of this ``resonance.``

  12. ECR (Electron Cyclotron Resonance) source for the HHIRF (Holifield Heavy Ion Research Facility) tandem accelerator

    SciTech Connect

    Olsen, D.K.; Alton, G.D.; Dowling, D.T.; Haynes, D.L.; Jones, C.M.; Juras, R.C.; Lane, S.N.; Meigs, M.J.; Mills, G.D.; Mosko, S.W.; Tatum, B.A.

    1990-01-01

    Electron Cyclotron Resonance, ECR, ion source technology has developed rapidly since the original pioneering work of R. Geller and his group at Grenoble in the early 1970s. These ion sources are capable of producing intense beams of highly charged positive ions and are used extensively for cyclotron injection, linac injection, and atomic physics research. In this paper, the advantages of using an ECR heavy-ion source in the terminal of the Holifield Heavy Ion Research Facility (HHIRF) 25-MV tandem accelerator is discussed. A possible ECR system for installation in the HHIRF tandem terminal is described.

  13. Characterization of the fast ions distribution from ion cyclotron emission measurements

    NASA Astrophysics Data System (ADS)

    D'Inca, R.; Noterdaeme, J.-M.; ASDEX Upgrade Team

    2014-02-01

    The ion cyclotron emission (ICE) is triggered by the free energy from an anisotropic distribution of fast ions in cyclotron resonance with plasma waves. Several theories have been developed in the hope of using the spectrum featured by this emission to extract information on the fast ion population [3], but the strong coupling between the fast ions orbits, their energy profile and the plasma waves properties makes it difficult to disentangle the role of each actor in the emission. We present here the three main results which, once combined, have improved our understanding of ICE on ASDEX Upgrade: (1) the measurement of all the main types of ICE which enables a comparison of their properties and of their interactions, (2) the use of a fast acquisition system with an increased accuracy in the time and frequency processing of the signal where the fine structure of the emission is resolved and (3) the use of the Hamiltonian theoretical framework developed for ICRF heating. It unifies the analysis of large extension orbits and of their interactions with the plasma waves and reveals the respective roles of the fast ions (through their velocities) and of the waves (through their frequencies and wave numbers) in the resonance condition. If these results are confirmed on other machines, they could lead to the development of a non intrusive diagnostic for fast ions.

  14. Wall-loss distribution of charge breeding ions in an electron cyclotron resonance ion source

    SciTech Connect

    Jeong, S. C.; Oyaizu, M.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Miyatake, H.; Niki, K.; Okada, M.; Watanabe, Y. X.; Otokawa, Y.; Osa, A.; Ichikawa, S.

    2011-03-15

    The ion loss distribution in an electron cyclotron resonance ion source (ECRIS) was investigated to understand the element dependence of the charge breeding efficiency in an electron cyclotron resonance (ECR) charge breeder. The radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions (typical nonvolatile and volatile elements, respectively) were injected into the ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex to breed their charge states. Their respective residual activities on the sidewall of the cylindrical plasma chamber of the source were measured after charge breeding as functions of the azimuthal angle and longitudinal position and two-dimensional distributions of ions lost during charge breeding in the ECRIS were obtained. These distributions had different azimuthal symmetries. The origins of these different azimuthal symmetries are qualitatively discussed by analyzing the differences and similarities in the observed wall-loss patterns. The implications for improving the charge breeding efficiencies of nonvolatile elements in ECR charge breeders are described. The similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.

  15. Predictive ion source control using artificial neural network for RFT-30 cyclotron

    NASA Astrophysics Data System (ADS)

    Kong, Young Bae; Hur, Min Goo; Lee, Eun Je; Park, Jeong Hoon; Park, Yong Dae; Yang, Seung Dae

    2016-01-01

    An RFT-30 cyclotron is a 30 MeV proton accelerator for radioisotope production and fundamental research. The ion source of the RFT-30 cyclotron creates plasma from hydrogen gas and transports an ion beam into the center region of the cyclotron. Ion source control is used to search source parameters for best quality of the ion beam. Ion source control in a real system is a difficult and time consuming task, and the operator should search the source parameters by manipulating the cyclotron directly. In this paper, we propose an artificial neural network based predictive control approach for the RFT-30 ion source. The proposed approach constructs the ion source model by using an artificial neural network and finds the optimized parameters with the simulated annealing algorithm. To analyze the performance of the proposed approach, we evaluated the simulations with the experimental data of the ion source. The performance results show that the proposed approach can provide an efficient way to analyze and control the ion source of the RFT-30 cyclotron.

  16. Modeling electromagnetic ion cyclotron waves in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Gamayunov, Konstantin; Engebretson, Mark; Zhang, Ming; Rassoul, Hamid

    The evolution of He+-mode electromagnetic ion cyclotron (EMIC) waves is studied inside the geostationary orbit using our global model of ring current (RC) ions, electric field, plasmasphere, and EMIC waves. In contrast to the approach previously used by Gamayunov et al. [2009], however, we do not use the bounce-averaged wave kinetic equation but instead use a complete, non bounce-averaged, equation to model the evolution of EMIC wave power spectral density, including off-equatorial wave dynamics. The major results of our study can be summarized as follows. (1) The thermal background level for EMIC waves is too low to allow waves to grow up to the observable level during one pass between the “bi-ion latitudes” (the latitudes where the given wave frequency is equal to the O+-He+ bi-ion frequency) in conjugate hemispheres. As a consequence, quasi-field-aligned EMIC waves are not typically produced in the model if the thermal background level is used, but routinely observed in the Earth’s magnetosphere. To overcome this model-observation discrepancy we suggest a nonlinear energy cascade from the lower frequency range of ultra low frequency waves into the frequency range of EMIC wave generation as a possible mechanism supplying the needed level of seed fluctuations that guarantees growth of EMIC waves during one pass through the near equatorial region. The EMIC wave development from a suprathermal background level shows that EMIC waves are quasi-field-aligned near the equator, while they are oblique at high latitudes, and the Poynting flux is predominantly directed away from the near equatorial source region in agreement with observations. (2) An abundance of O+ strongly controls the energy of oblique He+-mode EMIC waves that propagate to the equator after their reflection at “bi-ion latitudes”, and so it controls a fraction of wave energy in the oblique normals. (3) The RC O+ not only causes damping of the He+-mode EMIC waves but also causes wave generation

  17. Model of electromagnetic ion cyclotron waves in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Gamayunov, K. V.; Engebretson, M. J.; Zhang, M.; Rassoul, H. K.

    2014-09-01

    The evolution of He+-mode electromagnetic ion cyclotron (EMIC) waves is studied inside the geostationary orbit using our global model of ring current (RC) ions, electric field, plasmasphere, and EMIC waves. In contrast to the approach previously used by Gamayunov et al. (2009), however, we do not use the bounce-averaged wave kinetic equation but instead use a complete, nonbounce-averaged, equation to model the evolution of EMIC wave power spectral density, including off-equatorial wave dynamics. The major results of our study can be summarized as follows. (1) The thermal background level for EMIC waves is too low to allow waves to grow up to the observable level during one pass between the "bi-ion latitudes" (the latitudes where the given wave frequency is equal to the O+-He+ bi-ion frequency) in conjugate hemispheres. As a consequence, quasi-field-aligned EMIC waves are not typically produced in the model if the thermal background level is used, but routinely observed in the Earth's magnetosphere. To overcome this model-observation discrepancy we suggest a nonlinear energy cascade from the lower frequency range of ultralow frequency waves into the frequency range of EMIC wave generation as a possible mechanism supplying the needed level of seed fluctuations that guarantees growth of EMIC waves during one pass through the near equatorial region. The EMIC wave development from a suprathermal background level shows that EMIC waves are quasi field aligned near the equator, while they are oblique at high latitudes, and the Poynting flux is predominantly directed away from the near equatorial source region in agreement with observations. (2) An abundance of O+ strongly controls the energy of oblique He+-mode EMIC waves that propagate to the equator after their reflection at bi-ion latitudes, and so it controls a fraction of wave energy in the oblique normals. (3) The RC O+ not only causes damping of the He+-mode EMIC waves but also causes wave generation in the region

  18. Model of Electromagnetic Ion Cyclotron Waves in the Inner Magnetosphere

    NASA Astrophysics Data System (ADS)

    Gamayunov, K. V.; Engebretson, M. J.; Zhang, M.; Rassoul, H.

    2014-12-01

    The He-band electromagnetic ion cyclotron (EMIC) waves are studied using our global model of ring current (RC) ions, electric field, plasmasphere, and EMIC waves. In contrast to the approach by Gamayunov et al. [2009], however, we do not use the bounce-averaged kinetic equation for waves but instead use a complete, non bounce-averaged, equation to model EMIC wave power spectral density. The major results of our study can be summarized as follows. (1) The thermal background level for EMIC waves is too low to allow waves to grow up to the observable level during one pass between the "bi-ion latitudes" (the latitudes where the given wave frequency is equal to the O+-He+ bi-ion frequency) in conjugate hemispheres. As a consequence, quasi-field-aligned EMIC waves are not typically produced in the model if the thermal background level is used, but routinely observed in the Earth's magnetosphere. To overcome this model-observation discrepancy we suggest a nonlinear energy cascade from the lower frequency range of ULF waves into the frequency range of EMIC wave generation as a possible mechanism supplying the needed level of seed fluctuations that guarantees growth of EMIC waves during one pass through the near equatorial region. The EMIC wave development from a suprathermal background level shows that EMIC waves are quasi-field-aligned near the equator, while they are oblique at high latitudes, and the Poynting flux is predominantly directed away from the near equatorial source region in agreement with observations. (2) An abundance of O+ strongly controls the energy of oblique He-band EMIC waves that propagate to the equator after their reflection at "bi-ion latitudes", and so it controls a fraction of wave energy in the oblique normals. (3) The RC O+ not only causes damping of the He-band EMIC waves but also causes wave generation in the region of highly oblique wave normal angles, typically for θ > 82o, where a growth rate γ > 10-2 rad/s is frequently observed. The

  19. Microwave emission related to cyclotron instabilities in a minimum-B electron cyclotron resonance ion source plasma

    NASA Astrophysics Data System (ADS)

    Izotov, I.; Tarvainen, O.; Mansfeld, D.; Skalyga, V.; Koivisto, H.; Kalvas, T.; Komppula, J.; Kronholm, R.; Laulainen, J.

    2015-08-01

    Electron cyclotron resonance ion sources (ECRIS) have been essential in the research and applications of nuclear physics over the past 40 years. They are extensively used in a wide range of large-scale accelerator facilities for the production of highly charged heavy ion beams of stable and radioactive elements. ECRISs are susceptible to kinetic instabilities due to resonance heating mechanism leading to anisotropic electron velocity distribution function. Instabilities of cyclotron type are a proven cause of frequently observed periodic bursts of ‘hot’ electrons and bremsstrahlung, accompanied with emission of microwave radiation and followed by considerable drop of multiply charged ions current. Detailed studies of the microwave radiation associated with the instabilities have been performed with a minimum-B 14 GHz ECRIS operating on helium, oxygen and argon plasmas. It is demonstrated that during the development of cyclotron instability ‘hot’ electrons emit microwaves in sub-microsecond scale bursts at temporally descending frequencies in the 8-15 GHz range with two dominant frequencies of 11.09 and 12.59 GHz regardless of ECRIS settings i.e. magnetic field strength, neutral gas pressure or species and microwave power. The experimental data suggest that the most probable excited plasma wave is a slow extraordinary Z-mode propagating quasi-longitudinally with respect to the external magnetic field.

  20. High current DC negative ion source for cyclotron

    NASA Astrophysics Data System (ADS)

    Etoh, H.; Onai, M.; Aoki, Y.; Mitsubori, H.; Arakawa, Y.; Sakuraba, J.; Kato, T.; Mitsumoto, T.; Hiasa, T.; Yajima, S.; Shibata, T.; Hatayama, A.; Okumura, Y.

    2016-02-01

    A filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In Cs-free operation, continuous H- beam of 10 mA and D- beam of 3.3 mA were obtained stably at an arc-discharge power of 3 kW and 2.4 kW, respectively. In Cs-seeded operation, H- beam current reached 22 mA at a lower arc power of 2.6 kW with less co-extracted electron current. The optimum gas flow rate, which gives the highest H- current, was 15 sccm in the Cs-free operation, while it decreased to 4 sccm in the Cs-seeded operation. The relationship between H- production and the design/operating parameters has been also investigated by a numerical study with KEIO-MARC code, which gives a reasonable explanation to the experimental results of the H- current dependence on the arc power.

  1. Isotope exchange by Ion Cyclotron Wall Conditioning on JET

    NASA Astrophysics Data System (ADS)

    Wauters, T.; Douai, D.; Kogut, D.; Lyssoivan, A.; Brezinsek, S.; Belonohy, E.; Blackman, T.; Bobkov, V.; Crombé, K.; Drenik, A.; Graham, M.; Joffrin, E.; Lerche, E.; Loarer, T.; Lomas, P. L.; Mayoral, M.-L.; Monakhov, I.; Oberkofler, M.; Philipps, V.; Plyusnin, V.; Sergienko, G.; Van Eester, D.

    2015-08-01

    The isotopic exchange efficiencies of JET Ion Cyclotron Wall Conditioning (ICWC) discharges produced at ITER half and full field conditions are compared for JET carbon (C) and ITER like wall (ILW). Besides an improved isotope exchange rate on the ILW providing cleaner plasma faster, the main advantage compared to C-wall is a reduction of the ratio of retained discharge gas to removed fuel. Complementing experimental data with discharge modeling shows that long pulses with high (∼240 kW coupled) ICRF power maximizes the wall isotope removal per ICWC pulse. In the pressure range 1-7.5 × 10-3 Pa, this removal reduces with increasing discharge pressure. As most of the wall-released isotopes are evacuated by vacuum pumps in the post discharge phase, duty cycle optimization studies for ICWC on JET-ILW need further consideration. The accessible reservoir by H2-ICWC at ITER half field conditions on the JET-ILW preloaded by D2 tokamak operation is estimated to be 7.3 × 1022 hydrogenic atoms, and may be exchanged within 400 s of cumulated ICWC discharge time.

  2. High current DC negative ion source for cyclotron.

    PubMed

    Etoh, H; Onai, M; Aoki, Y; Mitsubori, H; Arakawa, Y; Sakuraba, J; Kato, T; Mitsumoto, T; Hiasa, T; Yajima, S; Shibata, T; Hatayama, A; Okumura, Y

    2016-02-01

    A filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In Cs-free operation, continuous H(-) beam of 10 mA and D(-) beam of 3.3 mA were obtained stably at an arc-discharge power of 3 kW and 2.4 kW, respectively. In Cs-seeded operation, H(-) beam current reached 22 mA at a lower arc power of 2.6 kW with less co-extracted electron current. The optimum gas flow rate, which gives the highest H(-) current, was 15 sccm in the Cs-free operation, while it decreased to 4 sccm in the Cs-seeded operation. The relationship between H(-) production and the design/operating parameters has been also investigated by a numerical study with KEIO-MARC code, which gives a reasonable explanation to the experimental results of the H(-) current dependence on the arc power. PMID:26932017

  3. Ion cyclotron waves at Mars: Occurrence and wave properties

    NASA Astrophysics Data System (ADS)

    Wei, H. Y.; Cowee, M. M.; Russell, C. T.; Leinweber, H. K.

    2014-07-01

    Ion cyclotron waves (ICWs) are generated during the interaction between the solar wind and the Martian exosphere in a process called ion pickup. Mars Global Surveyor (MGS) detected waves near the proton gyrofrequency, indicating pickup of the exospheric hydrogen. To analyze these waves, we first improve the zero levels of the MGS magnetic field data taken during the first aerobreaking phase and then perform a statistical study of the ICWs observed from just outside the Martian bow shock to over 14 Mars radii away. These ICW events typically last for 5 to 30 min but can occasionally last for hours. The wave power decreases slowly with distance on both the upstream and downstream sides. From the variation of wave properties with the strength of the background field, we find that there are likely still remaining offsets in at least some the data sets even after applying our calibration technique. Thus, we use the events with a strong background field to examine the wave properties that depend on an accurate determination of the field direction and strength. We find the pickup angle associated with the largest occurrence rate of ICWs to be around 45°, but neither the wave amplitude, nor wave frequency, nor wave duration appear to vary with pickup angle. Finally, we find the waves with background field strength greater than 4 nT occur on both the positive and negative electric field sides of Mars but have a larger occurrence rate on the side of Mars in the positive electric field direction (which is defined as the direction of the cross product of the magnetic field vector and solar wind flow vector).

  4. A Tuning Method for Electrically Compensated Ion Cyclotron Resonance Mass Spectrometer Traps

    PubMed Central

    Brustkern, Adam M.; Rempel, Don L.; Gross, Michael L.

    2010-01-01

    We describe a method for tuning electrically compensated ion cyclotron resonance (ICR) traps by tracking the observed cyclotron frequency of an ion cloud at different oscillation mode amplitudes. Although we have used this method to tune the compensation voltages of a custom-built electrically compensated trap, the approach is applicable to other designs that incorporate electrical compensation. To evaluate the effectiveness of tuning, we examined the frequency shift as a function of cyclotron orbit size at different z-mode oscillation amplitudes. The cyclotron frequencies varied by ~ 12 ppm for ions with low z-mode oscillation amplitudes compared to those with high z-mode amplitudes. This frequency difference decreased to ~1 ppm by one iteration of trap tuning. PMID:20060743

  5. Electromagnetic Ion Cyclotron Waves in the Inner Magnetosphere

    NASA Astrophysics Data System (ADS)

    Gamayunov, K. V.; Engebretson, M. J.; Zhang, M.; Rassoul, H.

    2013-12-01

    The evolution of He+ mode electromagnetic ion cyclotron (EMIC) waves is studied in the Earth's magnetosphere using our global model of ring current (RC) ions, electric field, plasmasphere, and EMIC waves. In contrast to the approach previously used by Gamayunov et al. (2009), however, we do not use the bounce-averaged wave kinetic equation but instead use a complete, non bounce-averaged, equation to model the evolution of EMIC wave power spectral density, including off-equatorial wave dynamics. The results based on this new approach demonstrate overall agreement with statistical studies of EMIC waves in the inner magnetosphere. The major findings from our study can be summarized as follows. (1) The RC O+ not only causes damping of the He+ mode EMIC waves but also causes wave generation in the region of highly oblique wave normal angles, typically for θ > 82deg, where a growth rate γ > 0.01 rad/s is frequently observed. The wave instability is driven by the loss-cone feature in the RC O+ distribution function. (2) The O+ density strongly controls the He+ mode EMIC wave energetics. For the plasmaspheric O+ fraction less than 1.5%, the wave damping by RC O+ in the vicinity of the O+-He+ bi-ion frequency becomes strong enough leading to a strongly suppressed EMIC wave activity. This suggests that both the RC and thermal O+ should be carefully specified in the model, and RC O+ should be included not only in the imaginary part of wave dispersion relation but in the real part as well. (3) The thermal background level for the He+ mode EMIC waves is too low to allow waves to grow up to the observable level during one pass between the "bi-ion latitudes" in conjugate hemispheres. As a consequence, quasi-field-aligned EMIC waves are not typically produced in the model but routinely observed in the Earth's magnetosphere. Our estimates show that a nonlinear energy cascade from lower frequency pulsations (in the Pc 4 to lower Pc 2 frequency range) into the frequency range of Pc

  6. Electron cyclotron resonance ion source related development work for heavy-ion irradiation tests

    SciTech Connect

    Koivisto, H.; Suominen, P.; Tarvainen, O.; Virtanen, A.; Parkkinen, A.

    2006-03-15

    The European Space Agency (ESA) uses the facilities at the Accelerator Laboratory (Department of Physics, University of Jyvaeskylae: JYFL) for heavy-ion irradiation tests of electronic components. Electron cyclotron resonance ion source related development work has been carried out in order to meet the requirements set by the project. During the irradiation tests several beam changes are performed during the day. Therefore, the time needed for the beam changes has to be minimized. As a consequence, a beam cocktail having nearly the same m/q ratio is used. This makes it possible a quick tuning of the cyclotron to select the required ion for the irradiation. In addition to this requirement, very high charge states for the heavy elements are needed to reach a penetration depth of 100 {mu}m in silicon. In this article we present some procedures to optimize the ion source operation. We also present results of the first three-frequency heating tests. The main frequency of 14 GHz was fed from a klystron and both secondary frequencies were launched from a traveling-wave tube amplifier (TWTA). Two separate frequency generators were used simultaneously to provide different signals for the TWTA. During the test an improvement of about 20% was observed for {sup 84}Kr{sup 25+} and {sup 129}Xe{sup 30+} ion beams when the third frequency was applied.

  7. Dispersion relation of electrostatic ion cyclotron waves in multi-component magneto-plasma

    SciTech Connect

    Khaira, Vibhooti Ahirwar, G.

    2015-07-31

    Electrostatic ion cyclotron waves in multi component plasma composed of electrons (denoted by e{sup −}), hydrogen ions (denoted by H{sup +}), helium ions (denoted by He{sup +}) and positively charged oxygen ions (denoted by O{sup +})in magnetized cold plasma. The wave is assumed to propagate perpendicular to the static magnetic field. It is found that the addition of heavy ions in the plasma dispersion modified the lower hybrid mode and also allowed an ion-ion mode. The frequencies of the lower hybrid and ion- ion hybrid modes are derived using cold plasma theory. It is observed that the effect of multi-ionfor different plasma densities on electrostatic ion cyclotron waves is to enhance the wave frequencies. The results are interpreted for the magnetosphere has been applied parameters by auroral acceleration region.

  8. Unidirectional stripping extraction from a cyclotron which accelerates light as well as heavy ions

    NASA Astrophysics Data System (ADS)

    Ristić-Djurović, Jasna L.; Ćirković, Saša

    2003-03-01

    The VINCY Cyclotron (VINča CYclotron) is a multipurpose machine intended to accelerate light as well as heavy ions. To extract heavy ions with low energy and light ions an extraction system with stripping foil is used. Heavy ions with high energy will be extracted by means of an electrostatic deflector. The former extraction system will be manufactured and used first. The proposed unidirectional stripping extraction system is the optimal balance between the placement of the extraction line and the required diversity and quality of the extracted beam. The available range of extraction directions is set by geometry limitations.

  9. Simulation of electron behavior in PIG ion source for 9 MeV cyclotron

    NASA Astrophysics Data System (ADS)

    J. Mu, X.; Ghergherehchi, M.; H. Yeon, Y.; W. Kim, J.; S. Chai, J.

    2014-12-01

    In this paper, we focus on a PIG source for producing intense H-ions inside a 9 MeV cyclotron. The properties of the PIG ion source were simulated for a variety of electric field distributions and magnetic field strengths using a CST particle studio. After analyzing the secondary electron emission (SEE) as a function of both magnetic and electric field strengths, we found that for the modeled PIG geometry, a magnetic field strength of 0.2 T provided the best results in terms of the number of secondary electrons. Furthermore, at 0.2 T, the number of secondary electrons proved to be greatest regardless of the cathode potential. Also, the modified PIG ion source with quartz insulation tubes was tested in a KIRAMS-13 cyclotron by varying the gas flow rate and arc current, respectively. The capacity of the designed ion source was also demonstrated by producing plasma inside the constructed 9 MeV cyclotron. As a result, the ion source is verified as being capable of producing an intense H- beam and high ion beam current for the desired 9 MeV cyclotron. The simulation results provide experimental constraints for optimizing the strength of the plasma and final ion beam current at a target inside a cyclotron.

  10. Model for the description of ion beam extraction from electron cyclotron resonance ion sources

    SciTech Connect

    Spaedtke, P.

    2010-02-15

    The finite difference method trajectory code KOBRA3-INP has been developed now for 25 years to perform the simulation of ion beam extraction in three dimensions. Meanwhile, the code has been validated for different applications: high current ion beam extraction from plasma sources for ion implantation technology, neutral gas heating in fusion devices, or ion thrusters for space propulsion. One major issue of the development of this code was to improve the flexibility of the applied model for the simulation of different types of particle sources. Fixed emitter sources might be simulated with that code as well as laser ion sources, Penning ion sources, electron cyclotron resonance ion sources (ECRISs), or H{sup -} sources, which require the simulation of negative ions, negative electrons, and positive charges simultaneously. The model which has been developed for ECRIS has now been used to explore the conditions for the ion beam extraction from a still nonexisting ion source, a so called ARC-ECRIS [P. Suominen and F. Wenander, Rev. Sci. Instrum. 79, 02A305 (2008)]. It has to be shown whether the plasma generator has similar properties like regular ECRIS. However, the emittance of the extracted beam seems to be much better compared to an ECRIS equipped with a hexapole.

  11. C60 Secondary Ion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    SciTech Connect

    Smith, Donald F.; Robinson, Errol W.; Tolmachev, Aleksey V.; Heeren, Ronald M.; Pasa-Tolic, Ljiljana

    2011-12-15

    Secondary ion mass spectrometry (SIMS) has seen increased application for high spatial chemical imaging of complex biological surfaces. The advent and commercial availability of cluster and polyatomic primary ion sources (e.g. Au and Bi cluster and buckminsterfullerene (C60)) provide improved secondary ion yield and decreased fragmentation of surface species, thus accessibility to intact molecular ions. Despite developments in primary ion sources, development of mass spectrometers to fully exploit their advantages has been limited. Tandem mass spectrometry for identification of secondary ions is highly desirable, but implementation has proven to be difficult. Similarly, high mass resolution and high mass measurement accuracy would greatly improve the chemical specificity of SIMS. Here we combine, for the first time, the advantages of a C60 primary ion source with the ultra-high mass resolving power and high mass measurement accuracy of Fourier transform ion cyclotron resonance mass spectrometry. Mass resolving power in excess of 100,000 (m/Δm50%) is demonstrated, with mass measurement accuracies below 3 parts-per-million. Imaging of mouse brain tissue at 40 μm pixel size is shown. Tandem mass spectrometry of ions from biological tissue is demonstrated and molecular formulae can be assigned to fragment ions.

  12. Fast neutral beam ion source coupled to a Fourier transform ion cyclotron resonance mass spectrometer

    SciTech Connect

    Hill, N.C.; Limbach, P.A.; Shomo, R.E. II; Marshall, A.G. ); Appelhans, A.D.; Delmore, J.E. )

    1991-11-01

    The coupling of an autoneutralizing SF{sup {minus}}{sub 6} fast ion-beam gun to a Fourier transform ion cyclotron resonance (FT/ICR) mass spectrometer is described. The fast neutral beam provides for secondary-ion-type FT/ICR mass analysis (e.g., production of abundant pseudomolecular (M+H){sup +} ions) of involatile samples without the need for external ion injection, since ions are formed at the entrance to the ICR ion trap. The design, construction, and testing of the hybrid instrument are described. The feasibility of the experiment (for both broadband and high-resolution FT/ICR positive-ion mass spectra) is demonstrated with {ital tetra}-butylammonium bromide and a Tylenol{sup ( )} sample. The ability to analyze high molecular weight polymers with high mass resolution is demonstrated for Teflon{sup ( )}. All of the advantages of the fast neutral beam ion source previously demonstrated with quadrupole mass analysis are preserved, and the additional advantages of FT/ICR mass analysis (e.g., high mass resolving power, ion trapping) are retained.

  13. Fast neutral beam ion source coupled to a Fourier transform ion cyclotron resonance mass spectrometer

    NASA Astrophysics Data System (ADS)

    Hill, Nicholas C.; Limbach, Patrick A.; Shomo, Ronald E., II; Marshall, Alan G.; Appelhans, Anthony D.; Delmore, James E.

    1991-11-01

    The coupling of an autoneutralizing SF-6 fast ion-beam gun to a Fourier transform ion cyclotron resonance (FT/ICR) mass spectrometer is described. The fast neutral beam provides for secondary-ion-type FT/ICR mass analysis [e.g., production of abundant pseudomolecular (M+H)+ ions] of involatile samples without the need for external ion injection, since ions are formed at the entrance to the ICR ion trap. The design, construction, and testing of the hybrid instrument are described. The feasibility of the experiment (for both broadband and high-resolution FT/ICR positive-ion mass spectra) is demonstrated with tetra-butylammonium bromide and a Tylenol■ sample. The ability to analyze high molecular weight polymers with high mass resolution is demonstrated for Teflon■. All of the advantages of the fast neutral beam ion source previously demonstrated with quadrupole mass analysis are preserved, and the additional advantages of FT/ICR mass analysis (e.g., high mass resolving power, ion trapping) are retained.

  14. Heating of ions to superthermal energies in the topside ionosphere by electrostatic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Ungstrup, E.; Klumpar, D. M.; Heikkila, W. J.

    1979-01-01

    The soft particle spectrometer on the Isis 2 spacecraft occasionally observes fluxes of ions moving upward out of the ionosphere in the vicinity of the auroral oval. These ion fluxes are characterized by a sharp pitch angle distribution usually peaked at an angle somewhat greater than 90 deg, indicative of particles heated to a large transverse temperature in a narrow range below the spacecraft. The observations are interpreted in terms of electrostatic ion cyclotron waves, which heat the ions to superthermal energies transverse to the earth's magnetic field. When the transverse energy increases, the repulsive force of the earth's magnetic field, proportional to the particle magnetic moment, repels the particles away from the earth.

  15. Kinetic structure of slow shocks - Effects of the electromagnetic ion/ion cyclotron instability

    NASA Technical Reports Server (NTRS)

    Omidi, N.; Winske, D.

    1992-01-01

    The structure of slow magnetosonic shocks in the low beta regime is analyzed with attention given to ion heating and the effects of waves upstream of the electromagnetic ion/ion cyclotron (EMIIC) instability. Shock formation is assessed by means of three methods - a relaxation method and two based on dynamic flow interactions - to determine the effects of initialization and boundary conditions on the formation. Good solutions are found with the piston method and the similar flow-flow method in which the plasma is injected from two boundaries to form two slow shocks. Plasma parameters and shock normal angle are found to be the key variables dictating the structure of the magnetosonic shocks. Four unique classes of resultant shock structures are described in which classical, steady, or nonsteady behavior is found. The analysis also yields insight into the relationship between EMIIC instability and ion dissipation.

  16. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics.

    PubMed

    Yorita, T; Hatanaka, K; Fukuda, M; Ueda, H; Yasuda, Y; Morinobu, S; Tamii, A; Kamakura, K

    2014-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP. PMID:24593475

  17. Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physics

    SciTech Connect

    Yorita, T. Hatanaka, K.; Fukuda, M.; Ueda, H.; Yasuda, Y.; Morinobu, S.; Tamii, A.; Kamakura, K.

    2014-02-15

    An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

  18. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source.

    PubMed

    Shin, Chang Seouk; Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Lee, Seung Wook; Won, Mi-Sook

    2016-02-01

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1-10 mm(2). The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research. PMID:26931931

  19. Nitrogen ion implantation into various materials using 28 GHz electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Shin, Chang Seouk; Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Lee, Seung Wook; Won, Mi-Sook

    2016-02-01

    The installation of the 28 GHz electron cyclotron resonance ion source (ECRIS) ion implantation beamline was recently completed at the Korea Basic Science Institute. The apparatus contains a beam monitoring system and a sample holder for the ion implantation process. The new implantation system can function as a multipurpose tool since it can implant a variety of ions, ranging hydrogen to uranium, into different materials with precise control and with implantation areas as large as 1-10 mm2. The implantation chamber was designed to measure the beam properties with a diagnostic system as well as to perform ion implantation with an in situ system including a mass spectrometer. This advanced implantation system can be employed in novel applications, including the production of a variety of new materials such as metals, polymers, and ceramics and the irradiation testing and fabrication of structural and functional materials to be used in future nuclear fusion reactors. In this investigation, the first nitrogen ion implantation experiments were conducted using the new system. The 28 GHz ECRIS implanted low-energy, multi-charged nitrogen ions into copper, zinc, and cobalt substrates, and the ion implantation depth profiles were obtained. SRIM 2013 code was used to calculate the profiles under identical conditions, and the experimental and simulation results are presented and compared in this report. The depths and ranges of the ion distributions in the experimental and simulation results agree closely and demonstrate that the new system will enable the treatment of various substrates for advanced materials research.

  20. An all permanent magnet electron cyclotron resonance ion source for heavy ion therapy

    SciTech Connect

    Cao, Yun Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia

    2014-02-15

    A high charge state all permanent Electron Cyclotron Resonance ion source, Lanzhou All Permanent ECR ion source no. 3-LAPECR3, has been successfully built at IMP in 2012, which will serve as the ion injector of the Heavy Ion Medical Machine (HIMM) project. As a commercial device, LAPECR3 features a compact structure, small size, and low cost. According to HIMM scenario more than 100 eμA of C{sup 5+} ion beam should be extracted from the ion source, and the beam emittance better than 75 π*mm*mrad. In recent commissioning, about 120 eμA of C{sup 5+} ion beam was got when work gas was CH{sub 4} while about 262 eμA of C{sup 5+} ion beam was obtained when work gas was C{sub 2}H{sub 2} gas. The design and construction of the ion source and its low-energy transportation beam line, and the preliminary commissioning results will be presented in detail in this paper.

  1. ECR heavy-ion source for the LBL 88-inch cyclotron

    SciTech Connect

    Clark, D.J.; Kalnins, J.G.; Lyneis, C.M.

    1983-03-01

    An Electron Cyclotron Resonance (ECR) heavy-ion source is under construction at the LBL 88-Inch Cyclotron. This source will produce very-high-charge-state heavy ions, such as 0/sup 8 +/ and Ar/sup 12 +/, which will increase cyclotron energies by a factor of 2-4, up to A = 80. It is a two-stage source using room-temperature coils, a permanent-magnet sextupole, and a 6-9 GHz microwave system. Design features include adjustable first-to-second-stage plasma coupling, a variable second-stage mirror ratio, high-conductance radial pumping of the second stage, and a beam-diagnostic system. A remotely movable extraction electrode will optimize extraction efficiency. The project includes construction of a transport line and improvements to the cyclotron axial-injection system. The construction period is expected to be two years.

  2. Impact of Ring Current Ions on Electromagnetic Ion Cyclotron Wave Dispersion Relation

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.

    2007-01-01

    Effect of the ring current ions in the real part of electromagnetic ion Cyclotron wave dispersion relation is studied on global scale. Recent Cluster observations by Engebretson et al. showed that although the temperature anisotropy of is energetic (> 10 keV) ring current protons was high during the entire 22 November 2003 perigee pass, electromagnetic ion cyclotron waves were observed only in conjunction with intensification of the ion fluxes below 1 keV by over an order of magnitude. To study the effect of the ring current ions on the wave dispersive properties and the corresponding global wave redistribution, we use a self-consistent model of interacting ring current and electromagnetic ion cyclotron waves, and simulate the May 1998 storm. The main findings of our simulation can be summarized as follows: First, the plasma density enhancement in the night MLT sector during the main and recovery storm phases is mostly caused by injection of suprathermal plasma sheet H + (approximately < 1 keV), which dominate the thermal plasma density. Second, during the recovery storm phases, the ring current modification of the wave dispersion relation leads to a qualitative change of the wave patterns in the postmidnight-dawn sector for L > 4.75. This "new" wave activity is well organized by outward edges of dense suprathermal ring current spots, and the waves are not observed if the ring current ions are not included in the real part of dispersion relation. Third, the most intense wave-induced ring current precipitation is located in the night MLT sector and caused by modification of the wave dispersion relation. The strongest precipitating fluxes of about 8 X 10(exp 6)/ (cm(exp 2) - s X st) are found near L=5.75, MLT=2 during the early recovery phase on 4 May. Finally, the nightside precipitation is more intense than the dayside fluxes, even if there are less intense waves, because the convection field moves ring current ions into the loss cone on the nightside, but drives

  3. An experimental test of the electromagnetic ion cyclotron instability within the earth's magnetosphere

    NASA Technical Reports Server (NTRS)

    Mauk, B. H.; Mcpherron, R. L.

    1980-01-01

    Examples of propagating electromagnetic Alfven/ion cyclotron waves in plasma particle and magnetic field data observed by the ATS-6 geostationary satellite are discussed. These waves were viewed mainly near the afternoon and dusk regions of the earth's magnetosphere with normalized frequencies in the 0.05 to 0.5 range. Two wave events were analyzed: both appeared coincidentally with the encounter of cool plasma populations which joined the hot populations already present. An electromagnetic ion cyclotron instability was proposed as the wave generation mechanism; this theory was tested by evaluating the linear growth integrals under the measured anisotropic hot ion distribution.

  4. Multiaperture ion beam extraction from gas-dynamic electron cyclotron resonance source of multicharged ions

    SciTech Connect

    Sidorov, A.; Dorf, M.; Zorin, V.; Bokhanov, A.; Izotov, I.; Razin, S.; Skalyga, V.; Rossbach, J.; Spaedtke, P.; Balabaev, A.

    2008-02-15

    Electron cyclotron resonance ion source with quasi-gas-dynamic regime of plasma confinement (ReGIS), constructed at the Institute of Applied Physics, Russia, provides opportunities for extracting intense and high-brightness multicharged ion beams. Despite the short plasma lifetime in a magnetic trap of a ReGIS, the degree of multiple ionization may be significantly enhanced by the increase in power and frequency of the applied microwave radiation. The present work is focused on studying the intense beam quality of this source by the pepper-pot method. A single beamlet emittance measured by the pepper-pot method was found to be {approx}70 {pi} mm mrad, and the total extracted beam current obtained at 14 kV extraction voltage was {approx}25 mA. The results of the numerical simulations of ion beam extraction are found to be in good agreement with experimental data.

  5. Investigations on the structure of the extracted ion beam from an electron cyclotron resonance ion source

    SciTech Connect

    Spaedtke, P.; Lang, R.; Maeder, J.; Rossbach, J.; Tinschert, K.; Maimone, F.

    2012-02-15

    Using improved beam diagnostic tools, the structure of an ion beam extracted from an electron cyclotron resonance ion source (ECRIS) becomes visible. Especially viewing targets to display the beam profile and pepper pot devices for emittance measurements turned out to be very useful. On the contrary, diagnostic tools integrating over one space coordinate like wire harps for profile measurements or slit-slit devices, respectively slit-grid devices to measure the emittance might be applicable for beam transport investigations in a quadrupole channel, but are not very meaningful for investigations regarding the given ECRIS symmetry. Here we try to reproduce the experimentally found structure on the ion beam by simulation. For the simulation, a certain model has to be used to reproduce the experimental results. The model is also described in this paper.

  6. A glow discharge ion source with fourier transform ion cyclotron resonance mass spectrometric detection.

    PubMed

    Barhick, C M; Eyler, J R

    1992-02-01

    A glow discharge (CD) ion source has been coupled to a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer using a four-element electrostatic lens to accelerate and focus ions generated external to the instrument's high magnetic field into its analyzer cell. Like other CD mass spectrometers, GD-FT-ICR can provide a quantitative measure of bulk analyte concentration with good precision and accuracy. Although detection limits currently attainable are several orders of magnitude higher than the commercially available magnetic sector-based instrument, CD-FT-ICR holds promise for ultrahigh resolving power elemental mass analysis. Several schemes are proposed to lower the detection limits of the technique while still providing high enough resolution to resolve isobaric interferences. PMID:24242880

  7. Anisotropic distribution function of minority tail ions generated by strong ion-cyclotron resonance heating

    SciTech Connect

    Chang, C.S.; Colestock, P.

    1989-05-01

    The highly anisotropic particle distribution function of minority tail ions driven by ion-cyclotron resonance heating at the fundamental harmonic is calculated in a two-dimensional velocity space. It is assumed that the heating is strong enough to drive most of the resonant ions above the in-electron critical slowing-down energy. Simple analytic expressions for the tail distribution are obtained fro the case when the Doppler effect is sufficiently large to flatten the sharp pitch angle dependence in the bounce averaged qualilinear heating coefficient, D/sub b/, and for the case when D/sub b/ is assumed to be constant in pitch angle and energy. It is found that a simple constant-D/sub b/ solution can be used instead of the more complicated sharp-D/sub b/ solution for many analytic purposes. 4 refs., 4 figs.

  8. Time evolution of bremsstrahlung and ion production of an electron cyclotron resonance ion source

    SciTech Connect

    Tarvainen, Ollie; Ropponen, Tommi; Jones, Peter; Peura, Pauli

    2008-01-01

    Bremsstrahlung radiation measurement is one of the most commonly used plasma diagnostics methods. Most of the bremsstrahlung measurements with electron cyclotron resonance (ECR) ion sources have been performed in continuous operation mode yielding information only on the steady state bremsstrahlung emission. This article describes the results of bremsstrahlung and ion current measurement with the JYFL 14 GHz ECRIS operated in pulsed mode. The experiments reveal information about the bremsstrahlung radiation in plasma conditions before reaching the equilibrium. The time scale of bremsstrahlung production is compared to ion production time scale for different charge states. The bremsstrahlung data is presented with 2 millisecond time intervals as a function of neutral gas pressure and microwave power. Data from hundreds of microwave pulses is combined in order to have a sufficient amount of events at each time step. The relevant plasma physics phenomena during both, the leading and the trailing edge of the RF pulse, are discussed.

  9. Comparison of solar wind driving mechanisms: ion cyclotron resonance versus kinetic suprathermal electron effects

    NASA Astrophysics Data System (ADS)

    Tam, Sunny W. Y.; Chang, Tom

    2003-09-01

    The combined kinetic effects of two possible solar wind driving mechanisms, ion cyclotron resonance and suprathermal electrons, have been studied in the literature [1]. However, the individual contribution by these two mechanisms was unclear. We compare the two effects in the fast solar wind. Our basic model follows the global kinetic evolution of the solar wind under the influence of ion cyclotron resonance, while taking into account Coulomb collisions, and the ambipolar electric field that is consistent with the particle distributions themselves. The kinetic effects associated with the suprathermal electrons can be included in the model as an option. By comparing our results with and without this option, we conclude that, without considering any wave-particle interactions involving the electrons, the kinetic effects of the suprathermal electrons are relative insignificant in the presence of ion cyclotron resonance in terms of driving the solar wind.

  10. Ion Trap with Narrow Aperture Detection Electrodes for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Nagornov, Konstantin O.; Kozhinov, Anton N.; Tsybin, Oleg Y.; Tsybin, Yury O.

    2015-05-01

    The current paradigm in ion trap (cell) design for Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is the ion detection with wide aperture detection electrodes. Specifically, excitation and detection electrodes are typically 90° wide and positioned radially at a similar distance from the ICR cell axis. Here, we demonstrate that ion detection with narrow aperture detection electrodes (NADEL) positioned radially inward of the cell's axis is feasible and advantageous for FT-ICR MS. We describe design details and performance characteristics of a 10 T FT-ICR MS equipped with a NADEL ICR cell having a pair of narrow aperture (flat) detection electrodes and a pair of standard 90° excitation electrodes. Despite a smaller surface area of the detection electrodes, the sensitivity of the NADEL ICR cell is not reduced attributable to improved excite field distribution, reduced capacitance of the detection electrodes, and their closer positioning to the orbits of excited ions. The performance characteristics of the NADEL ICR cell are comparable with the state-of-the-art FT-ICR MS implementations for small molecule, peptide, protein, and petroleomics analyses. In addition, the NADEL ICR cell's design improves the flexibility of ICR cells and facilitates implementation of advanced capabilities (e.g., quadrupolar ion detection for improved mainstream applications). It also creates an intriguing opportunity for addressing the major bottleneck in FTMS—increasing its throughput via simultaneous acquisition of multiple transients or via generation of periodic non-sinusoidal transient signals.

  11. Sensitive test for ion-cyclotron resonant heating in the solar wind.

    PubMed

    Kasper, Justin C; Maruca, Bennett A; Stevens, Michael L; Zaslavsky, Arnaud

    2013-03-01

    Plasma carrying a spectrum of counterpropagating field-aligned ion-cyclotron waves can strongly and preferentially heat ions through a stochastic Fermi mechanism. Such a process has been proposed to explain the extreme temperatures, temperature anisotropies, and speeds of ions in the solar corona and solar wind. We quantify how differential flow between ion species results in a Doppler shift in the wave spectrum that can prevent this strong heating. Two critical values of differential flow are derived for strong heating of the core and tail of a given ion distribution function. Our comparison of these predictions to observations from the Wind spacecraft reveals excellent agreement. Solar wind helium that meets the condition for strong core heating is nearly 7 times hotter than hydrogen on average. Ion-cyclotron resonance contributes to heating in the solar wind, and there is a close link between heating, differential flow, and temperature anisotropy. PMID:23496700

  12. Studies on a Q/A selector for the SECRAL electron cyclotron resonance ion source

    SciTech Connect

    Yang, Y.; Sun, L. T.; Feng, Y. C.; Fang, X.; Lu, W.; Zhang, W. H.; Cao, Y.; Zhang, X. Z.; Zhao, H. W.

    2014-08-15

    Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented.

  13. Studies on a Q/A selector for the SECRAL electron cyclotron resonance ion source.

    PubMed

    Yang, Y; Sun, L T; Feng, Y C; Fang, X; Lu, W; Zhang, W H; Cao, Y; Zhang, X Z; Zhao, H W

    2014-08-01

    Electron cyclotron resonance ion sources are widely used in heavy ion accelerators in the world because they are capable of producing high current beams of highly charged ions. However, the design of the Q/A selector system for these devices is challenging, because it must have a sufficient ion resolution while controlling the beam emittance growth. Moreover, this system has to be matched for a wide range of ion beam species with different intensities. In this paper, research on the Q/A selector system at the SECRAL (Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou) platform both in experiment and simulation is presented. Based on this study, a new Q/A selector system has been designed for SECRAL II. The features of the new design including beam simulations are also presented. PMID:25173256

  14. Observation of Inverse Ion-Cyclotron Damping Induced by Parallel-Velocity Shear

    NASA Astrophysics Data System (ADS)

    Teodorescu, C.; Reynolds, E. W.; Koepke, M. E.

    2002-08-01

    The generation of broadband multiharmonic spectra of electrostatic ion-cyclotron waves is demonstrated in a magnetized laboratory plasma in which shear in the magnetic-field-aligned (parallel) ion flow and a relative parallel electron drift are present. Shear correlates with an increased number of harmonics and a decreased electron drift speed. Wave and particle measurements indicate that cyclotron damping is reduced and even becomes negative. The fluctuations in the time domain are spiky, similar to electric-field fluctuations observed both in Earth's auroral zone and in numerical simulations.

  15. Electron cyclotron resonance ion source experience at the Heidelberg Ion Beam Therapy Center.

    PubMed

    Winkelmann, T; Cee, R; Haberer, T; Naas, B; Peters, A; Scheloske, S; Spädtke, P; Tinschert, K

    2008-02-01

    Radiotherapy with heavy ions is an upcoming cancer treatment method with to date unparalleled precision. It associates higher control rates particularly for radiation resistant tumor species with reduced adverse effects compared to conventional photon therapy. The accelerator beam lines and structures of the Heidelberg Ion Beam Therapy Center (HIT) have been designed under the leadership of GSI, Darmstadt with contributions of the IAP Frankfurt. Currently, the accelerator is under commissioning, while the injector linac has been completed. When the patient treatment begins in 2008, HIT will be the first medical heavy ion accelerator in Europe. This presentation will provide an overview about the project, with special attention given to the 14.5 GHz electron cyclotron resonance (ECR) ion sources in operation with carbon, hydrogen, helium, and oxygen, and the experience of one year of continuous operation. It also displays examples for beam emittances, measured in the low energy beam transport. In addition to the outlook of further developments at the ECR ion sources for a continuously stable operation, this paper focuses on some of the technical processings of the past year. PMID:18315121

  16. Effect of Ion Cyclotron Heating on Fast Ion Transport and Plasma Rotation in Tokamaks

    NASA Astrophysics Data System (ADS)

    Chan, V. S.; Omelchenko, Y. A.; Chiu, S. C.

    2000-10-01

    Minority ion cyclotron heating can produce energetic ions with banana orbits which are finite compared with the minor radius of a tokamak. The radial transport of the fast ions in the presence of Coulomb collisions results in a radial current and a corresponding JxB torque density on the bulk plasma. Collisions with the bulk ions provides an additional frictional torque that adds to or opposes the magnetic torque. This study clarifies the various mechanisms which can contribute to the torque components including collision-induced finite orbit particle diffusion, wave-induced asymmetry in canonical momentum when doppler resonance is accounted for, and orbit asymmetry created by magnetic geometry. Ion dynamics are calculated with a Monte-Carlo code in which wave-induced energy diffusion is accounted for by a quasilinear operator. The code follows particle drift trajectories in a tokamak geometry under the influence of RF fields and collisions with the background plasma. Questions on the direction of plasma rotation under different conditions and validity of the Green's function approach in modeling RF-induced rotation will be addressed.

  17. A 1D Model For Describing Ion Cyclotron Resonance Heating At Arbitrary Cyclotron Harmonics

    NASA Astrophysics Data System (ADS)

    Van Eester, Dirk; Lerche, Ernesto

    2011-12-01

    Both at low and higher cyclotron harmonics, properly accounting for finite Larmor radius effects is crucial in many ICRF heating scenario's creating high energy tails. The present paper discusses an extension of the 1D TOMCAT wave equation solver [1] to arbitrary harmonics and arbitrary wavelengths. Rather than adopting the particle position, the guiding center position is used as the independent variable when writing down an expression for the dielectric response that is suitable for numerical application. This choice of variable yields symmetric and intuitive expressions, and guarantees that a positive definite power absorption is obtained for any of the wave modes in the plasma. Rather than relying on a truncated Taylor series expansion of the dielectric response, an integro-differential approach is proposed. To keep the required computation time for this generalized description reasonable tabulation of integrals is intensively used. An example is provided to illustrate the potential of the new wave code.

  18. Improved Ion Optics for Introduction of Ions into a 9.4 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; Dang, Xibei; Ibrahim, Yehia M.; Norheim, Randolph V.; Anderson, Gordon A.; Smith, Richard D.; Marshall, Alan G.

    2014-01-01

    Enhancements to the ion source and transfer optics of our 9.4 T FT-ICR mass spectrometer have resulted in improved ion transmission efficiency for more sensitive mass measurement of complex mixtures at the MS and MS/MS levels. The tube lens/skimmer has been replaced by a dual ion funnel and the following octopole by a quadrupole for reduced ion cloud radial expansion before transmission into a mass-selective quadrupole. The number of ions that reach the ICR cell is increased by an order of magnitude for the funnel/quadrupole relative to the tube lens/skimmer/octopole. PMID:25601704

  19. Ion-cyclotron instability in plasmas described by product-bi-kappa distributions

    SciTech Connect

    Santos, M. S. dos; Ziebell, L. F. Gaelzer, R.

    2015-12-15

    The dispersion relation for parallel propagating waves in the ion-cyclotron branch is investigated numerically by considering that the velocity distribution of the ion population is a function of type product-bi-kappa. We investigate the effects of the non-thermal features and of the anisotropy associated with this type of distribution on the ion-cyclotron instability, as well as the influence of different forms of the electron distribution, by considering Maxwellian distributions, bi-kappa distributions, and product-bi-kappa distributions. The cases of ions described by either Maxwellian or bi-kappa distributions are also considered, for comparison. The results of the numerical analysis show that the increase in the non-thermal character associated with the anisotropic kappa distributions for ions contributes to enhance the instability as compared to that obtained in the Maxwellian case, in magnitude and in wave number range, with more significant enhancement for the case of ion product-bi-kappa distributions than for the case of ion bi-kappa distributions. It is also shown that the ion-cyclotron instability is decreased if the electrons are described by product-bi-kappa distributions, while electrons described by bi-kappa distributions lead to growth rates which are very similar to those obtained considering a Maxwellian distribution for the electron population.

  20. Latitudinal dependence of nonlinear interaction between electromagnetic ion cyclotron wave and terrestrial ring current ions

    SciTech Connect

    Su, Zhenpeng Zhu, Hui; Zheng, Huinan; Xiao, Fuliang; Zhang, Min; Liu, Y. C.-M.; Shen, Chao; Wang, Yuming; Wang, Shui

    2014-05-15

    Electromagnetic ion cyclotron (EMIC) waves can lead to the rapid decay (on a timescale of hours) of the terrestrial ring current. Such decay process is usually investigated in the framework of quasi-linear theory. Here, both theoretical analysis and test-particle simulation are performed to understand the nonlinear interaction between ring current ions and EMIC waves. In particular, the dependence of the nonlinear wave-particle interaction processes on the ion initial latitude is investigated in detail. These nonlinear processes are classified into the phase trapping and phase bunching, and the phase bunching is further divided into the channel and cluster effects. Compared to the prediction of the quasi-linear theory, the ring current decay rate can be reduced by the phase trapping, increased by the channel effect phase bunching, but non-deterministically influenced by the cluster effect phase bunching. The ion initial latitude changes the occurrence of the phase trapping, modulates the transport direction and strength of the cluster effect phase bunching, and only slightly affects the channel effect phase bunching. The current results suggest that the latitudinal dependence of these nonlinear processes should be considered in the evaluation of the ring current decay induced by EMIC waves.

  1. A CW radiofrequency ion source for production of negative hydrogen ion beams for cyclotrons

    SciTech Connect

    Kalvas, T.; Tarvainen, O.; Komppula, J.; Koivisto, H.; Tuunanen, J.; Potkins, D.; Stewart, T.; Dehnel, M. P.

    2015-04-08

    A CW 13.56 MHz radiofrequency-driven ion source RADIS for production of H{sup −} and D{sup −} beams is under development for replacing the filament-driven ion source of the MCC30/15 cyclotron. The RF ion source has a 16-pole multicusp plasma chamber, an electromagnet-based magnetic filter and an external planar spiral RF antenna behind an AlN window. The extraction is a 5-electrode system with an adjustable puller electrode voltage for optimizing the beam formation, a water-cooled electron dump electrode and an accelerating einzel lens. At 2650 W of RF power, the source produces 1 mA of H{sup −} (2.6 mA/cm{sup 2}), which is the intensity needed at injection for production of 200 µA H{sup +} with the filament-driven ion source. A simple pepperpot device has been developed for characterizing the beam emittance. Plans for improving the power efficiency with the use of a new permanent magnet front plate is discussed.

  2. Oscillating two stream instability of electromagnetic pump in the ion cyclotron range of frequency in a plasma

    SciTech Connect

    Ahmad, Nafis; Tripathi, V. K.; Rafat, M.; Husain, Mudassir M.

    2009-06-15

    An analytical formalism of oscillating two stream instability of a large amplitude electromagnetic wave in the ion cyclotron range of frequency in a plasma is developed. The instability produces electrostatic ion cyclotron sidebands and a driven low frequency mode. The nonlinear coupling arises primarily due to the motion of ions and is strong when the pump frequency is close to ion cyclotron frequency and the oscillatory ion velocity is a significant fraction of acoustic speed. For propagation perpendicular to the ambient magnetic field, the X-mode pump wave produces flute type perturbation with maximum growth rate at some specific wavelengths, which are three to four times larger than the ion Larmor radius. For propagation at oblique angles to ambient magnetic field, the ion cyclotron O-mode, the growth rate increases with the wave number of the low frequency mode.

  3. SELF-CONSISTENT ION CYCLOTRON ANISOTROPY-BETA RELATION FOR SOLAR WIND PROTONS

    SciTech Connect

    Isenberg, Philip A.; Maruca, Bennett A.; Kasper, Justin C. E-mail: bmaruca@ssl.berkeley.edu

    2013-08-20

    We derive a set of self-consistent marginally stable states for a system of ion-cyclotron waves propagating parallel to the large-scale magnetic field through a homogeneous proton-electron plasma. The proton distributions and the wave dispersions are related through the condition that no further ion-cyclotron resonant particle scattering or wave growth/damping may take place. The thermal anisotropy of the protons in these states therefore defines the threshold value for triggering the proton-cyclotron anisotropy instability. A number of recent papers have noted that the anisotropy of solar wind protons at 1 AU does not seem to be limited by the proton-cyclotron anisotropy threshold, even at low plasma beta. However, this puzzle seems to be due solely to the estimation of this anisotropy threshold under the assumption that the protons have a bi-Maxwellian distribution. We note that bi-Maxwellian distributions are never marginally stable to the resonant cyclotron interaction, so these estimates do not represent physically valid thresholds. The threshold anisotropies obtained from our marginally stable states are much larger, as a function of proton parallel beta, than the bi-Maxwellian estimates, and we show that the measured data remains below these more rigorous thresholds. Thus, the results of this paper resolve the apparent contradiction presented by the solar wind anisotropy observations at 1 AU: the bi-Maxwellian anisotropies are not rigorous thresholds, and so do not limit the proton distributions in the solar wind.

  4. Production of flickering aurora and field-aligned electron flux by electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Temerin, M.; Mcfadden, J.; Boehm, M.; Carlson, C. W.; Lotko, W.

    1986-01-01

    Recent observations have suggested that flickering aurora is produced by a modulation of the field-aligned component of the electron flux within an auroral arc. It is proposed that a portion of the field-aligned electrons are of ionospheric origin and that these electrons are accelerated and their flux modulated by electromagnetic ion cyclotron waves that occur below the main acceleration region on auroral arc field lines. A model of the electromagnetic ion cyclotron wave shows that the parallel phase velocity of the wave increase as the wave propagates toward the ionosphere. A test particle calculation shows that ionospheric electrons trapped or reflected by the wave are accelerated to energies of several keV and that their flux is modulated at the wave frequency. The relative amplitudes of the model wave electric fields are consistent with the observations of small-scale low-frequency ionospheric and magnetospheric electric fields near auroral arcs of approximately 10 mV/m and 100 mV/m, respectively. The large-amplitude ion cyclotron waves also produce a ponderomotive force and a self-consistent ambipolar electric field. Energy considerations show that the downward energy flux in the electromagnetic ion cyclotron wave can be several percent of the total downward auroral electron energy flux.

  5. Transport in JET H-mode Plasmas with Beam and Ion Cyclotron Heating

    SciTech Connect

    R.V. Budny, et. al.

    2012-07-13

    Ion Cyclotron (IC) Range of Frequency waves and neutral beam (NB) injection are planned for heating in ITER and other future tokamaks. It is important to understand transport in plasmas with NB and IC to plan, predict, and improve transport and confinement. Transport predictions require simulations of the heating profiles, and for this, accurate modeling of the IC and NB heating is needed.

  6. Effect of a RF Wave on Ion Cyclotron Instability in Size Distributed Impurities Containing Plasmas

    SciTech Connect

    Sharma, A. K.; Tripathi, V. K.; Annou, R.

    2008-09-07

    The effect of a large amplitude lower hybrid wave on current driven ion cyclotron waves in a dusty plasma where dust grains are size distributed is examined. The influence of the lower hybrid wave on the stabilization of the instability is studied. The efficacy of rf is dust density dependent.

  7. Nonlinear kinetic simulations of ion cyclotron emission from fusion products in large tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Dendy, Richard; Cook, James; Chapman, Sandra

    2012-10-01

    Ion cyclotron emission (ICE) was the only collective radiative instability, driven by fusion-born ions, observed from deuterium-tritium plasmas in both JET and TFTR (R O Dendy et al., Nucl. Fusion 35, 1733 (1995)). Suprathermal emission, peaked at sequential ion cyclotron harmonics at the outer mid-plane edge, was detected using heating antennas as receivers on JET and using probes in TFTR. The intensity of ICE spectral peaks scaled linearly with fusion reactivity. The underlying emission mechanism appears to be the magnetoacoustic cyclotron instability (MCI), which involves resonance between: the fast Alfv'en wave; cyclotron harmonic waves supported by the energetic ions and by the background thermal plasma; and a set of centrally born fusion products, lying on barely trapped orbits, which undergo large drift excursions. Analytical studies show that the linear growth rate of the MCI corresponds well with certain observational features of ICE, including ones where a nonlinear treatment might be thought essential. To help explain this, we have carried out direct numerical simulations using a particle-in-cell (PIC) code. We focus on the results of extending MCI theory from the linear into the nonlinear regime for large tokamak parameters.

  8. Ion heating in the ion cyclotron range of frequencies in the Wisconsin Tokapole II

    SciTech Connect

    Biddle, A. P.

    1980-06-01

    Ion temperatures of 75 eV, a doubling of the ohmic heating temperature in a normal discharge, have been achieved using the fast magnetosonic wave heating at the second, third, and fourth harmonics of the cyclotron frequency in a single component hydrogen plasma. The wave launching structure is a single turn, shielded, insulated loop which constitutes the inductor of the rf source tank circuit. Power levels of 800 kW have been applied to the plasma for periods of up to 1.1 milliseconds. Good agreement has been found between theory and experiment for loading and wave propagation in the plasma for m = 0 and m = +1 modes. Eigenmodes have been observed by peaking of both the rf wave amplitude and the loading of the oscillator, as well as by oscillator frequency shifts imposed by their passage.

  9. Excitation of electrostatic ion-cyclotron waves by an ion beam in a two-ion component plasma

    SciTech Connect

    Sharma, Jyotsna; Sharma, Suresh C.

    2010-12-15

    An ion beam propagating through a magnetized plasma cylinder containing electrons, light positive potassium ions (K{sup +}), and heavy positive cesium ions (Cs{sup +}) drives electrostatic ion cyclotron (EIC) waves to instability via Cerenkov interaction. Two EIC wave modes are present, the K{sup +} and Cs{sup +} modes. The unstable wave frequencies and the growth rate of both the light positive ion and heavy positive ion modes increase with an increase in their relative ion concentrations. The growth rate of both the unstable modes (K{sup +} and Cs{sup +}) scales one-third power of the beam density. The real part of the frequency of both the unstable modes (K{sup +} and Cs{sup +}) increases with the beam energy and scales as almost one-half power of the beam energy. Numerical calculations of the growth rate and mode frequencies have been carried out for the parameters of the experiment of Suszcynsky et al. [J. Geophys. Res. 94, 8966 (1989)]. It is found that the unstable wave frequencies of both the light positive ion and heavy positive ion modes increase with the magnetic fields in accordance with the experimental observations.

  10. Energy transfer between energetic ring current H(+) and O(+) by electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Thorne, Richard M.; Horne, Richard B.

    1994-01-01

    Electromagnetic ion cyclotron (EMIC) waves in the frequency range below the helium gyrofrequency can be excited in the equatorial region of the outer magnetosphere by cyclotron resonant instability with anisotropic ring current H(+) ions. As the unducted waves propagate to higher latitudes, the wave normal should become highly inclined to the ambient magnetic field. Under such conditions, wave energy can be absorbed by cyclotron resonant interactions with ambient O(+), leading to ion heating perpendicular to the ambient magnetic field. Resonant wave absorption peaks in the vicinity of the bi-ion frequency and the second harmonic of the O(+) gyrofrequrency. This absorption should mainly occur at latitudes between 10 deg and 30 deg along auroral field lines (L is greater than or equal to 7) in the postnoon sector. The concomitant ion heating perpendicular to the ambient magnetic field can contribute to the isotropization and geomagnetic trapping of collapsed O(+) ion conics (or beams) that originate from a low-altitude ionospheric source region. During geomagnetic storms when the O(+) content of the magnetosphere is significantly enhanced, the absorption of EMIC waves should become more efficient, and it may contribute to the observed acceleration of O(+) ions of ionospheric origin up to ring current energies.

  11. Status of the ITER ion cyclotron heating and current drive system

    NASA Astrophysics Data System (ADS)

    Lamalle, P.; Beaumont, B.; Kazarian, F.; Gassmann, T.; Agarici, G.; Montemayor, T. Alonzo; Bamber, R.; Bernard, J.-M.; Boilson, D.; Cadinot, A.; Calarco, F.; Colas, L.; Courtois, X.; Deibele, C.; Durodié, F.; Fano, J.; Fredd, E.; Goulding, R.; Greenough, N.; Hillairet, J.; Jacquinot, J.; Kaye, A. S.; Kočan, M.; Labidi, H.; Leichtle, D.; Loarte, A.; McCarthy, M.; Messiaen, A.; Meunier, L.; Mukherjee, A.; Oberlin-Harris, C.; Patel, A. M.; Peters, B.; Rajnish, K.; Rasmussen, D.; Sanabria, R.; Sartori, R.; Singh, R.; Swain, D.; Trivedi, R. G.; Turner, A.

    2015-12-01

    The paper reports on latest developments for the ITER Ion Cyclotron Heating and Current Drive system: imminent acceptance tests of a prototype power supply at full power; successful factory acceptance of candidate RF amplifier tubes which will be tested on dedicated facilities; further design integration and experimental validation of transmission line components under 6MW hour-long pulses. The antenna Faraday shield thermal design has been validated above requirements by cyclic high heat flux tests. R&D on ceramic brazing is under way for the RF vacuum windows. The antenna port plug RF design is stable but major evolution of the mechanical design is in preparation to achieve compliance with the load specification, warrant manufacturability and incorporate late interface change requests. The antenna power coupling capability predictions have been strengthened by showing that, if the plasma scrape-off layer turns out to be steep and the edge density low, the reference burning plasma can realistically be displaced to improve the coupling.

  12. Gas Feeding System Supplying the U-400M Cyclotron Ion Source with Hydrogen Isotopes

    SciTech Connect

    Yukhimchuk, A.A.; Angilopov, V.V.; Apasov, V.A.

    2005-07-15

    Automated system feeding into ion source hydrogen isotopes as molecules with preset ratio of the fluxes is described. The control system automatically maintained the working parameters and provided graphic and digital representation of the controlled processes. The radiofrequency (RF) ion source installed at the axial injection line of the cyclotron produced ion beams of HD{sup +}, HT{sup +}, DT{sup +}, D{sub 2}H{sup +}, etc. At a several months DT{sup +} beam acceleration the tritium consumption was less than 108 Bq/hr. The intensity of a 58.2 MeV triton beam (T{sup +} ions) extracted from the cyclotron chamber was about 10 nA.

  13. Vacuum Ultraviolet Photodissociation and Fourier Transform-Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry: Revisited.

    PubMed

    Shaw, Jared B; Robinson, Errol W; Paša-Tolić, Ljiljana

    2016-03-15

    We revisited the implementation of 193 nm ultraviolet photodissociation (UVPD) within the ion cyclotron resonance (ICR) cell of a Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer. UVPD performance characteristics were examined in the context of recent developments in the understanding of UVPD and in-cell tandem mass spectrometry. Efficient UVPD and photo-ECD of a model peptide and proteins within the ICR cell of a FT-ICR mass spectrometer are accomplished through appropriate modulation of laser pulse timing, relative to ion magnetron motion and the potential applied to an ion optical element upon which photons impinge. It is shown that UVPD yields efficient and extensive fragmentation, resulting in excellent sequence coverage for model peptide and protein cations. PMID:26882021

  14. A comprehensive analysis of ion cyclotron waves in the equatorial magnetosphere of Saturn

    NASA Astrophysics Data System (ADS)

    Meeks, Zachary; Simon, Sven; Kabanovic, Slawa

    2016-09-01

    We present a comprehensive analysis of ion cyclotron waves in the equatorial magnetosphere of Saturn, considering all magnetic field data collected during the Cassini era (totaling to over 4 years of data from the equatorial plane). This dataset includes eight targeted flybys of Enceladus, three targeted flybys of Dione, and three targeted flybys of Rhea. Because all remaining orbits of Cassini are high-inclination, our study provides the complete map of ion cyclotron waves in Saturn's equatorial magnetosphere during the Cassini era. We provide catalogs of the radial and longitudinal dependencies of the occurrence rate and amplitude of the ion cyclotron fundamental and first harmonic wave modes. The fundamental wave mode is omnipresent between the orbits of Enceladus and Dione and evenly distributed across all Local Times. The occurrence rate of the fundamental mode displays a Fermi-Dirac-like profile with respect to radial distance from Saturn. Detection of the first harmonic mode is a rare event occurring in only 0.49% of measurements taken and always in conjunction with the fundamental mode. We also search for a dependency of the ion cyclotron wave field on the orbital positions of the icy moons Enceladus, Dione, and Rhea. On magnetospheric length scales, the wave field is independent of the moons' orbital positions. For Enceladus, we analyze wave amplitude profiles of seven close flybys (E9, E12, E13, E14, E17, E18, and E19), which occurred during the studied trajectory segments, to look for any local effects of Enceladan plume variability on the wave field. We find that even in the close vicinity of Enceladus, the wave amplitudes display no discernible dependency on Enceladus' angular distance to its orbital apocenter. Thus, the correlation between plume activity and angular distance to apocenter proposed by Hedman et al. (2013) does not leave a clearly distinguishable imprint in the ion cyclotron wave field.

  15. Status of the Bio-Nano electron cyclotron resonance ion source at Toyo University

    SciTech Connect

    Uchida, T.; Minezaki, H.; Ishihara, S.; Muramatsu, M.; Kitagawa, A.; Drentje, A. G.; Rácz, R.; Biri, S.; Asaji, T.; Kato, Y.; Yoshida, Y.

    2014-02-15

    In the paper, the material science experiments, carried out recently using the Bio-Nano electron cyclotron resonance ion source (ECRIS) at Toyo University, are reported. We have investigated several methods to synthesize endohedral C{sub 60} using ion-ion and ion-molecule collision reaction in the ECRIS. Because of the simplicity of the configuration, we can install a large choice of additional equipment in the ECRIS. The Bio-Nano ECRIS is suitable not only to test the materials production but also to test technical developments to improve or understand the performance of an ECRIS.

  16. Comparative study of ion cyclotron waves at Mars, Venus and Earth

    NASA Astrophysics Data System (ADS)

    Wei, H. Y.; Russell, C. T.; Zhang, T. L.; Blanco-Cano, X.

    2011-08-01

    Ion cyclotron waves are generated in the solar wind when it picks up freshly ionized planetary exospheric ions. These waves grow from the free energy of the highly anisotropic distribution of fresh pickup ions, and are observed in the spacecraft frame with left-handed polarization and a wave frequency near the ion's gyrofrequency. At Mars and Venus and in the Earth's polar cusp, the solar wind directly interacts with the planetary exospheres. Ion cyclotron waves with many similar properties are observed in these diverse plasma environments. The ion cyclotron waves at Mars indicate its hydrogen exosphere to be extensive and asymmetric in the direction of the interplanetary electric field. The production of fast neutrals plays an important role in forming an extended exosphere in the shape and size observed. At Venus, the region of exospheric proton cyclotron wave production may be restricted to the magnetosheath. The waves observed in the solar wind at Venus appear to be largely produced by the solar-wind-Venus interaction, with some waves at higher frequencies formed near the Sun and carried outward by the solar wind to Venus. These waves have some similarity to the expected properties of exospherically produced proton pickup waves but are characterized by magnetic connection to the bow shock or by a lack of correlation with local solar wind properties respectively. Any confusion of solar derived waves with exospherically derived ion pickup waves is not an issue at Mars because the solar-produced waves are generally at much higher frequencies than the local pickup waves and the solar waves should be mostly absorbed when convected to Mars distance as the proton cyclotron frequency in the plasma frame approaches the frequency of the solar-produced waves. In the Earth's polar cusp, the wave properties of ion cyclotron waves are quite variable. Spatial gradients in the magnetic field may cause this variation as the background field changes between the regions in which

  17. First operation of the charge-breeder electron-cyclotron-resonance ion source at the Texas A and M Cyclotron Institute

    SciTech Connect

    May, D. P.; Tabacaru, G.; Abegglen, F. P.; Cornelius, W. D.

    2010-02-15

    The 14.5 GHz electron-cyclotron-resonance ion source (ECRIS) designed and fabricated specifically for charge breeding has been installed at the Texas A and M University Cyclotron Institute for use in the institute's ongoing radioactive-ion-beam upgrade. The initial testing of the source has just begun with magnetic analysis of the ECRIS beam. The source has only been conditioning for a brief time at low microwave power, and it is continuing to improve. After the source has been conditioned and characterized, charge-breeding trials with stable beams from a singly ionizing source will begin.

  18. Ion cyclotron anisotropy instabilities in the magnetosheath - Theory and simulations

    NASA Technical Reports Server (NTRS)

    Gary, S. P.; Mckean, Michael E.; Winske, Dan

    1993-01-01

    Second-order theory and 1D hybrid computer simulations are used to examine the nonlinear properties of proton and helium cyclotron anisotropy instabilities in the terrestrial magnetosheath at relatively weak fluctuations levels and at propagation parallel to the background magnetic field. The simulations confirm the second-order predictions that both instabilities yield efficient wave-particle interactions; the rate at which the driving species anisotropy is reduced is much greater than the rate at which that species loses kinetic energy. It is suggested that these instabilities should saturate at relatively low levels. An approximate expression is derived for the fluctuating field energy at saturation of the fastest growing modes, and it is found that it is in fair agreement with three computer simulations.

  19. Results of RIKEN superconducting electron cyclotron resonance ion source with 28 GHz.

    PubMed

    Higurashi, Y; Ohnishi, J; Nakagawa, T; Haba, H; Tamura, M; Aihara, T; Fujimaki, M; Komiyama, M; Uchiyama, A; Kamigaito, O

    2012-02-01

    We measured the beam intensity of highly charged heavy ions and x-ray heat load for RIKEN superconducting electron cyclotron resonance ion source with 28 GHz microwaves under the various conditions. The beam intensity of Xe(20+) became maximum at B(min) ∼ 0.65 T, which was ∼65% of the magnetic field strength of electron cyclotron resonance (B(ECR)) for 28 GHz microwaves. We observed that the heat load of x-ray increased with decreasing gas pressure and field gradient at resonance zone. It seems that the beam intensity of highly charged heavy ions with 28 GHz is higher than that with 18 GHz at same RF power. PMID:22380155

  20. Observations of ion cyclotron waves near synchronous orbit and on the ground

    NASA Technical Reports Server (NTRS)

    Fraser, B. J.

    1985-01-01

    Ion cyclotron waves (ICWs) generated in the magnetosphere by the ion cyclotron instability of 10-100 keV protons are now known to be the origin of short-period (0.1-5 Hz) electromagnetic field oscillations observed by synchronous spacecraft and on the earth's surface. Observations of the various wave characteristics, including spectral and polarization properties, that lead to the identification of generation and propagation mechaniisms, and regions in the magnetosphere are described with reference to ATS-6, GEOS, and ground-based wave data and interpreted using cold plasma propagation theory. The presence of heavy ions (O/+/, He/+/) dramatically modifies ICW magnetospheric propagation characteristics giving rise to spectral slots and polarization reversals. These properties may be used in plasma diagnostics. Finally satellite-ground correlations and techniques for determining the magnetospheric source position of ICWs not seen at synchronous orbit but observed on the ground as structured Pc1 pulsations are considered.

  1. Ion cyclotron waves at unmagnetized bodies: a comparison of Mars, Venus and Titan

    NASA Astrophysics Data System (ADS)

    Wei, H.; Russell, C. T.; Cowee, M.; Blanco-Cano, X.; Zhang, T.; Dougherty, M. K.

    2009-12-01

    Mars, Venus and Titan do not have appreciable global magnetic fields. Their high-altitude neutral atmospheres are not shielded from being lost to the solar wind and the Saturnian magnetosphere. When the atmospheric hydrogen atoms of Mars and Venus are ionized and picked up by the solar wind, proton cyclotron waves are created from the free energy of the ring-beam distribution of the pick-up ions. At Mars, proton cyclotron waves observed by Mars Global Surveyor extend from the magnetosheath to over 12 Mars radii, with intermittent occurrence and amplitudes slowly varying with distance. The wave occurrence pattern indicates a disk-shaped hydrogen exosphere of Mars with asymmetry in the direction of the interplanetary electric field. Fast neutrals produced by neutralization of the pickup ions can travel across fieldlines to distant regions where they get re-ionized and produce waves far downstream. Thus the top of Mars exosphere extends in a disk to high altitude, with its orientation controlled by the interplanetary magnetic field. At Venus, plasma waves having properties similar to ion cyclotron waves are observed in the solar wind around the planet by Venus Express, with wave frequencies that range from 0.2 to 5.9 times of the proton gyrofrequency. Statistical study shows that the waves with frequency higher than 1.5 times the proton gyrofrequency are not generated locally and are similar to the waves observed at 0.3 AU and 1 AU which appear to be created near the Sun and convected outward with the solar wind. The rest of the waves are mostly magnetically connected to the bow shock, so they are probably generated by particles backstreaming from the shock and propagate out further from the foreshock. At Titan, ion cyclotron waves are not observed although wave generation is expected due to the large pickup rate of hydrocarbon ions at high altitude of Titan. We attempt to understand the lack of ion cyclotron waves at Titan using hybrid simulations. Studying and

  2. Parametric coupling of lower hybrid wave with gyrating ion beam driven ion cyclotron instability in a plasma

    SciTech Connect

    Singh, Rohtash; Tripathi, V. K.

    2013-07-15

    A lower hybrid wave, launched into a tokamak for supplementary heating in the presence of neutral beam turned gyrating ion beam, is seen to excite some prominent channels of parametric decay. The beam driven deuterium cyclotron mode is further destabilized by the lower hybrid pump through the nonlinear 4-wave coupling, involving higher and lower frequency lower hybrid sidebands, when ω{sub 0}/k{sub 0z}v{sub 0z}=(1−ω{sub LH}{sup 2}/ω{sub 0}{sup 2}) , where ω{sub LH} is the lower hybrid frequency, ω{sub 0} and k{sub 0z} are the frequency and parallel wave number of the pump wave, and v{sub 0z} is the velocity of ion beam parallel to the magnetic field. The growth rate increases with parallel wave number of the ion-cyclotron mode. The pump is also susceptible to parametric upconversion into an upper sideband shifted by the frequency of the negative energy deuterium cyclotron mode. For typical parameters, the growth rate of this channel is around one fiftieth of deuterium cyclotron frequency and falls off with the transverse wave number of the mode.

  3. A 1D model for describing ion cyclotron resonance heating at arbitrary cyclotron harmonics in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Van Eester, Dirk; Lerche, Ernesto

    2013-05-01

    Both at low and higher cyclotron harmonics, properly accounting for finite Larmor radius effects is crucial in many ion cyclotron resonance frequency heating scenario's creating high energy tails. This paper discusses an extension TOMCAT-U of the 1D TOMCAT tokamak plasma wave equation solver (Van Eester and Koch 1998 Plasma Phys. Control. Fusion 40 1949) to arbitrary harmonics and arbitrary wavelengths while only keeping leading order terms in equilibrium variation terms. Rather than adopting the particle position, the guiding center position is used as the independent variable when writing down an expression for the dielectric response that is suitable for numerical application. This choice of independent variable yields intuitive expressions involving the Kennel-Engelmann operator which can directly be linked to the corresponding expressions in the RF diffusion operator appearing in the Fokker-Planck equation. It also guarantees that a positive definite power transfer from waves to particles is ensured for any of the wave modes in a plasma in which all populations have a Maxwellian distribution, as is expected from first principles. Rather than relying on a truncated Taylor series expansion of the dielectric response, an integrodifferential approach that retains all finite Larmor radius effects is proposed. To keep the required computation time for this generalized description reasonable, tabulation of integrals is intensively used. Although the accent is on the presentation of the upgraded formalism as well as the adopted recursions and tabulations, a few examples are provided to illustrate the potential of the new wave code that relies on these tabulations.

  4. Observations of single-pass ion cyclotron heating in a trans-sonic flowing plasma

    NASA Astrophysics Data System (ADS)

    Bering, E. A.; Díaz, F. R. Chang; Squire, J. P.; Glover, T. W.; Carter, M. D.; McCaskill, G. E.; Longmier, B. W.; Brukardt, M. S.; Chancery, W. J.; Jacobson, V. T.

    2010-04-01

    The VAriable Specific Impulse Magnetoplasma Rocket (VASIMR®) is a high power electric spacecraft propulsion system, capable of Isp/thrust modulation at constant power [F. R. Chang Díaz et al., Proceedings of the 39th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 8-11 Jan. 2001]. The VASIMR® uses a helicon discharge to generate plasma. This plasma is energized by an rf booster stage that uses left hand polarized slow mode waves launched from the high field side of the ion cyclotron resonance. In the experiments reported in this paper, the booster uses 2-4 MHz waves with up to 50 kW of power. This process is similar to the ion cyclotron heating (ICH) in tokamaks, but in the VASIMR® the ions only pass through the resonance region once. The rapid absorption of ion cyclotron waves has been predicted in recent theoretical studies. These theoretical predictions have been supported with several independent measurements in this paper. The single-pass ICH produced a substantial increase in ion velocity. Pitch angle distribution studies showed that this increase took place in the resonance region where the ion cyclotron frequency was roughly equal to the frequency on the injected rf waves. Downstream of the resonance region the perpendicular velocity boost should be converted to axial flow velocity through the conservation of the first adiabatic invariant as the magnetic field decreases in the exhaust region of the VASIMR®. This paper will review all of the single-pass ICH ion acceleration data obtained using deuterium in the first VASIMR® physics demonstrator machine, the VX-50. During these experiments, the available power to the helicon ionization stage increased from 3 to 20+ kW. The increased plasma density produced increased plasma loading of the ICH coupler. Starting with an initial demonstration of single-pass ion cyclotron acceleration, the experiments demonstrate significant improvements in coupler efficiency and in ion heating efficiency. In

  5. ENSEMBLE SIMULATIONS OF PROTON HEATING IN THE SOLAR WIND VIA TURBULENCE AND ION CYCLOTRON RESONANCE

    SciTech Connect

    Cranmer, Steven R.

    2014-07-01

    Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the identity of the physical processes that energize non-Maxwellian protons in the solar wind, but a traditional favorite has been the dissipation of ion cyclotron resonant Alfvén waves. This paper presents kinetic models of how ion cyclotron waves heat protons on their journey from the corona to interplanetary space. It also derives a wide range of new solutions for the relevant dispersion relations, marginal stability boundaries, and nonresonant velocity-space diffusion rates. A phenomenological model containing both cyclotron damping and turbulent cascade is constructed to explain the suppression of proton heating at low alpha-proton differential flow speeds. These effects are implemented in a large-scale model of proton thermal evolution from the corona to 1 AU. A Monte Carlo ensemble of realistic wind speeds, densities, magnetic field strengths, and heating rates produces a filled region of parameter space (in a plane described by the parallel plasma beta and the proton temperature anisotropy ratio) similar to what is measured. The high-beta edges of this filled region are governed by plasma instabilities and strong heating rates. The low-beta edges correspond to weaker proton heating and a range of relative contributions from cyclotron resonance. On balance, the models are consistent with other studies that find only a small fraction of the turbulent power spectrum needs to consist of ion cyclotron waves.

  6. Are Ring Current Ions Lost in Electromagnetic Ion Cyclotron Wave Dispersion Relation?

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.

    2006-01-01

    Electromagnetic ion cyclotron (EMIC) waves are widely observed in the inner and outer magnetosphere, at geostationary orbit, at high latitudes along the plasmapause, and at the ionospheric altitudes. Interaction of the Ring Current (RC) ions and EMIC waves causes ion scattering into the loss cone and leads to decay of the RC, especially during the main phase of storms when the RC decay times of about one hour or less are observed. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Induced scattering of these waves by the plasmaspheric thermal ions leads to ion temperature enhancement, and forms a so-called hot zone near the plasmapause where the temperature of core plasma ions can reach tens of thousands of degrees. Relativistic electrons in the outer radiation belt also interact well with the EMIC waves, and during the main and/or recovery phases of the storms these electrons can easily be scattered into the loss cone over a time scale from several hours to a day. The plasma density distribution in the magnetosphere and the ion content play a critical role in EMIC wave generation and propagation, but the wave dispersion relation in the known RC-EMIC wave interaction models is assumed to be determined by the thermal plasma distribution only. In these models, the modification of the EMIC wave dispersion relation caused by the RC ions is not taken into account, and the RC ions are only treated as a source of free energy in order to generate EMIC waves. At the same time, the RC ions can dominate the thermal magnetospheric content in the night MLT sector at great L shells during the main and/or recovery storm phase. In this study, using our self-consistent RC-EMIC wave model [Khazanov et al., 2006], we simulate the May 1998 storm in order to quantify the global EMIC wave redistribution caused by

  7. Effect of Ring Current Ions on Electromagnetic Ion Cyclotron Wave Dispersion Relation

    NASA Technical Reports Server (NTRS)

    Gamayunov, K. V.; Khazanov, G. V.

    2006-01-01

    Electromagnetic ion cyclotron (EMIC) waves are widely observed in the inner and outer magnetosphere, at geostationary orbit, at high latitudes along the plasmapause, and at the ionospheric altitudes. Interaction of the Ring Current (RC) ions and EMIC waves causes ion scattering into the loss cone and leads to decay of the RC, especially during the main phase of storms when the RC decay times of about one hour or less are observed. The oblique EMIC waves damp due to Landau resonance with the thermal plasmaspheric electrons, and subsequent transport of the dissipating wave energy into the ionosphere below causes an ionosphere temperature enhancement. Induced scattering of these waves by the plasmaspheric thermal ions leads to ion temperature enhancement, and forms a so-called hot zone near the plasmapause where the temperature of core plasma ions can reach tens of thousands of degrees. Relativistic electrons in the outer radiation belt also interact well with the EMIC waves, and during the main and/or recovery phases of the storms these electrons can easily be scattered into the loss cone over a time scale from several hours to a day. The plasma density distribution in the magnetosphere and the ion content play a critical role in EMIC wave generation and propagation, but the wave dispersion relation in the known RC-EMIC wave interaction models is assumed to be determined by the thermal plasma distribution only. In these models, the modification of the EMIC wave dispersion relation caused by the RC ions is not taken into account, and the RC ions are only treated as a source of free energy in order to generate EMIC waves. At the same time, the RC ions can dominate the thermal magnetospheric content in the night MLT sector at great L shells during the main and/or recovery storm phase. In this study, using our self-consistent RC-EMIC wave model [Khazanov et al., 2006], we simulate the May 1998 storm in order to quantify the global EMIC wave redistribution caused by

  8. Propagation and absorption of ion cyclotron resonant waves in an FRC configuration

    NASA Astrophysics Data System (ADS)

    Ceccherini, Francesco; Galeotti, Laura; Brambilla, Marco; Barnes, Daniel C.; Yang, Xiaokang; TAE Team

    2013-10-01

    The generation and propagation of an ion cyclotron resonant wave is studied in a Field Reversed Configuration (FRC) plasma which includes at least two different ion species. We consider minority heating as the main process through which energy is transferred to the ions and we take two scenarios into account. In the first scenario the charge/mass ratio of the minority species is higher than the corresponding ratio of the majority species and in the second scenario the opposite is considered. The first case is particularly interesting because it allows the study of absorption rates of ions for frequency values higher than the maximun cyclotron frequency of the majority species and lower than the maximum cyclotron frequency of the minority species. In such a frequency range the majority species can absorb energy through second or higher harmonic processes only. Because of the very peculiar magnetic field structure of FRCs, the second scenario may be required in case the resonance process must take place in the very inner regions of the plasma. In this latter case the electron absorption may play a very significant role and we give a preliminary description of the key parameters in the antenna configuration, which can reduce or enhance such an effect.

  9. Ground-satellite study of a Pc 1 ion cyclotron wave event

    SciTech Connect

    Fraser, B.J.; Kemp, W.J.; Webster, D.J. )

    1989-09-01

    The magnetospheric generation and propagation characteristics of ion cyclotron waves associated with a Pc 1 emission observed by a network of four middle and low-latitude ground stations are determined using ground source location techniques and ISEE 1 plasma data. The source region at L = 4.7 {plus minus} 0.7 is determined from propagation in the F{sub 2} region ionospheric duct using wave polarization characteristics at ground stations. This source is just inside the steep plasmapause seen by ISEE 1 at L = 4.9 {plus minus} 0.1. The ion cyclotron wave packet interhemispheric bounce period measured from the ground spectra increases with time from 140 to 155 s during the event but is in agreement with dispersion calculations undertaken using ISEE 1 electron density and cool to cold ion composition data in a H{sup +} plasma with 8-10% He{sup +} and <1% O{sup +} ions. The frequency of the Pc 1 emission band seen on the ground (0.5-0.8 Hz) corresponds to the propagation region between the equatorial O{sup +} cutoff frequency and the He{sup +} cyclotron frequency. Linear convective growth rate calculations inside the plasmapause show significant wave amplitudes in this band. With these results it is possible to completely describe the wave generation mechanism and the magnetosphere ionosphere propagation characteristics for the Pc 1 event.

  10. ICRH of JET and LHD Majority Ions at Their Fundamental Cyclotron Frequency

    SciTech Connect

    Krasilnikov, A. V.; Kaschuck, Yu. A.; Amosov, V. N.; Van Eester, D.; Lerche, E.; Mailloux, J.; Stamp, M.; Jachmich, S.; Leggate, H.; Walden, A.; Mayoral, M.-L.; Santala, M.; Kiptily, V.; Popovichev, S.; Vdovin, V.; Biewer, T.; Crombe, K.; Esposito, B.

    2007-09-28

    Results of the experimental studies of ICRH at the fundamental cyclotron frequency of the majority deuterons in JET plasmas with near-tangential deuteron neutral beam injection (NBI) are presented. 1D, 2D and 3D ICRH modeling indicated that several ITER relevant mechanisms of heating may occur simultaneously in this heating scheme: fundamental ion cyclotron resonance heating of majority and beam D ions, impurity ion heating and electron heating due to Landau damping and TTMP. These mechanisms were studied in JET experiments with a {approx}90% D, 5% H plasma including traces of Be and Ar. Up to 2MW of ICRH power was applied at 25 MHz to NBI heated plasmas. In most of the discharges the toroidal magnetic field strength was 3.3T, but in one it was equal to 3.6T. The E{sub +} component of the electric field governs the ion cyclotron heating of not too fast particles. The Doppler shifted RF absorption of the beam deuterons away from the cold resonance at which E{sub +} is small was exploited to enhance the RF power absorption efficiency. Fundamental ICRH experiments were also carried out in LHD hydrogen plasma with high energy hydrogen NBI. ICRH was performed at 38MHz with injected power <1 MW. The effect of fundamental ICRH was clearly demonstrated in both machines.

  11. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T {perpendicular} {ne} T{parallel}and with appreciable drift velocity along the confining magnetic field. Single ``dressed`` test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between ``kinetic or causal instabilities`` and ``hydrodynamic instabilities`` are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k{parallel} = 0 for k{parallel} {ne} 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an ``inverted`` population of states.

  12. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T [perpendicular] [ne] T[parallel]and with appreciable drift velocity along the confining magnetic field. Single dressed'' test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between kinetic or causal instabilities'' and hydrodynamic instabilities'' are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k[parallel] = 0 for k[parallel] [ne] 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an inverted'' population of states.

  13. Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

    DOEpatents

    Alton, G.D.

    1998-11-24

    Microwave injection methods are disclosed for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant ``volume`` ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources. 5 figs.

  14. Production of large resonant plasma volumes in microwave electron cyclotron resonance ion sources

    DOEpatents

    Alton, Gerald D.

    1998-01-01

    Microwave injection methods for enhancing the performance of existing electron cyclotron resonance (ECR) ion sources. The methods are based on the use of high-power diverse frequency microwaves, including variable-frequency, multiple-discrete-frequency, and broadband microwaves. The methods effect large resonant "volume" ECR regions in the ion sources. The creation of these large ECR plasma volumes permits coupling of more microwave power into the plasma, resulting in the heating of a much larger electron population to higher energies, the effect of which is to produce higher charge state distributions and much higher intensities within a particular charge state than possible in present ECR ion sources.

  15. X-ray-spectroscopy analysis of electron-cyclotron-resonance ion-source plasmas

    SciTech Connect

    Santos, J. P.; Martins, M. C.; Parente, F.; Costa, A. M.; Marques, J. P.; Indelicato, P.

    2010-12-15

    Analysis of x-ray spectra emitted by highly charged ions in an electron-cyclotron-resonance ion source (ECRIS) may be used as a tool to estimate the charge-state distribution (CSD) in the source plasma. For that purpose, knowledge of the electron energy distribution in the plasma, as well as the most important processes leading to the creation and de-excitation of ionic excited states are needed. In this work we present a method to estimate the ion CSD in an ECRIS through the analysis of the x-ray spectra emitted by the plasma. The method is applied to the analysis of a sulfur ECRIS plasma.

  16. Generation of plasma rotation by ion cyclotron resonance heating in tokamaks

    SciTech Connect

    Chang, C.S.; Phillips, C.K.; White, R.; Zweben, S.; Bonoli, P.T.; Rice, J.E.; Greenwald, M.J.; deGrassie, J.

    1999-05-01

    A physical mechanism for generation of a plasma rotation and radial electric field by ion cyclotron resonance heating (ICRH) is presented in a tokamak geometry. By breaking the omnigenity of resonant ion orbits, ICRH can induce a nonambipolar minor-radial transport of resonant ions. This yields a radial charge separation, a modification to radial electric field E{sub r}, and the generation of plasma rotation. It is estimated that the ICRH fast-wave power available in the present-day tokamak experiments can be large enough to give a significant modification to plasma rotation. {copyright} {ital 1999 American Institute of Physics.}

  17. Strong Pitch-Angle Diffusion of the Ring Current Ions Induced by Electromagnetic ion Cyclotron Waves

    NASA Astrophysics Data System (ADS)

    Gamayunov, K. V.; Khazanov, G. V.

    2005-12-01

    Deep and intense circulation of the magnetospheric plasma during geomagnetic storm is building up an energy content of the terrestrial ring current (RC) to an unusually high level, and the RC intensity strongly influence the storm-time space weather. The recovery of Dst index takes place hours or days after Dst minimum, and is caused by the decay of magnetopause and magnetotail current systems, and removal of the RC ions due to charge exchange, convection through the dayside magnetopause, Coulomb scattering, RC interaction with electromagnetic ion cyclotron (EMIC) waves, and scattering by field-line curvature. During the early recovery phase, the RC loss rate is about one hour or less, and it is more rapid than charge exchange can support. Ion scattering into the loss cone by EMIC waves is believed to be responsible for such fast RC decay during this storm stage. However, most RC-EMIC wave interaction models do not predict the strong pitch-angle diffusion that is theoretically discussed and observed in the Earth magnetosphere (particularly by SEPS detectors on board of the POLAR satellite). In present work, we employ our self-consistent RC-EMIC wave model in order to study systematically the occurrence of the RC strong pitch-angle diffusion caused by interaction with waves during the May 1998 storm. Most of cases of the strong diffusion and of the intense EMIC waves are located in the afternoon-premidnight MLT sector at 3 < L < 6, and exhibit significant linear correlation. During the early recovery phase (at about 08 UT on May 4), the entire RC energy range (less than 450 keV) is subject to strong pitch-angle diffusion. Although the flux transitions between trapped zone and loss cone are steeper for higher energy RC protons than for main body of the distribution function, the pitch-angle distributions are highly isotropic for all energies both inside and outside of the loss cone.

  18. An ICR study of ion-molecule reactions of PH(n)+ ions. [of importance to interstellar chemistry, using ion cyclotron resonance techniques

    NASA Technical Reports Server (NTRS)

    Thorne, L. R.; Anicich, V. G.; Huntress, W. T.

    1983-01-01

    The reactions of PH(n)+ ions (n = 0-3) were examined with a number of neutrals using ion-cyclotron-resonance techniques. The reactions examined have significance for the distribution of phosphorus in interstellar molecules. The results indicate that interstellar molecules containing the P-O bond are likely to be more abundant than those containing the P-H bond.

  19. Formation of a conical distribution and intense ion heating in the presence of hydrogen cyclotron waves

    NASA Astrophysics Data System (ADS)

    Okuda, H.; Ashour-Abdalla, M.

    1981-07-01

    In the considered investigation, it is assumed that the field aligned currents are responsible for producing electrostatic harmonic cyclotron waves (EHC). Using a one-dimensional simulation model in which the electron velocity distribution is maintained by a constant injection of the initial distribution, it is shown that, in contrast to earlier initial value simulations, EHC waves grow to a large amplitude, resulting in the formation of an anisotropic ion velocity distribution. Both the heating rate and the anisotropy are in reasonable agreement with the quasi-linear theory, taking into account the cyclotron resonance. The results show that the saturation is due to the combined effects of wave induced diffusion in an electron velocity space and the heating of ions perpendicularly. Both these effects reduce the growth rate.

  20. Origin of ion-cyclotron turbulence in the downward Birkeland current region

    SciTech Connect

    Basu, B.; Jasperse, J. R.; Lund, E. J.; Grossbard, N.

    2011-02-15

    Linear stability analysis of the electron velocity distributions, which are observed in the FAST satellite measurements in the downward Birkeland current region of the magnetosphere, is presented. The satellite-measured particle (electrons and protons) velocity distributions are fitted with analytic functions and the dispersion relation is derived in terms of the plasma dispersion functions associated with those distribution functions. Numerical solutions of the dispersion relation show that the bump-on-tail structure of the electron velocity distribution can excite electrostatic ion-cyclotron instabilities by the Landau resonance mechanism. Nonlinear evolution of these instabilities may explain the observed electrostatic ion-cyclotron turbulence in the Birkeland current region. Excitation of other types of instabilities by the fitted electron velocity distributions and their relevance are also discussed.

  1. Power requirements for electron cyclotron current drive and ion cyclotron resonance heating for sawtooth control in ITER

    NASA Astrophysics Data System (ADS)

    Chapman, I. T.; Graves, J. P.; Sauter, O.; Zucca, C.; Asunta, O.; Buttery, R. J.; Coda, S.; Goodman, T.; Igochine, V.; Johnson, T.; Jucker, M.; La Haye, R. J.; Lennholm, M.; Contributors, JET-EFDA

    2013-06-01

    13 MW of electron cyclotron current drive (ECCD) power deposited inside the q = 1 surface is likely to reduce the sawtooth period in ITER baseline scenario below the level empirically predicted to trigger neoclassical tearing modes (NTMs). However, since the ECCD control scheme is solely predicated upon changing the local magnetic shear, it is prudent to plan to use a complementary scheme which directly decreases the potential energy of the kink mode in order to reduce the sawtooth period. In the event that the natural sawtooth period is longer than expected, due to enhanced α particle stabilization for instance, this ancillary sawtooth control can be provided from >10MW of ion cyclotron resonance heating (ICRH) power with a resonance just inside the q = 1 surface. Both ECCD and ICRH control schemes would benefit greatly from active feedback of the deposition with respect to the rational surface. If the q = 1 surface can be maintained closer to the magnetic axis, the efficacy of ECCD and ICRH schemes significantly increases, the negative effect on the fusion gain is reduced, and off-axis negative-ion neutral beam injection (NNBI) can also be considered for sawtooth control. Consequently, schemes to reduce the q = 1 radius are highly desirable, such as early heating to delay the current penetration and, of course, active sawtooth destabilization to mediate small frequent sawteeth and retain a small q = 1 radius. Finally, there remains a residual risk that the ECCD + ICRH control actuators cannot keep the sawtooth period below the threshold for triggering NTMs (since this is derived only from empirical scaling and the control modelling has numerous caveats). If this is the case, a secondary control scheme of sawtooth stabilization via ECCD + ICRH + NNBI, interspersed with deliberate triggering of a crash through auxiliary power reduction and simultaneous pre-emptive NTM control by off-axis ECCD has been considered, permitting long transient periods with high fusion

  2. Use of a krypton isotope for rapid ion changeover at the Lawrence Berkeley Laboratory 88-inch cyclotron

    NASA Technical Reports Server (NTRS)

    Soli, George A.; Nichols, Donald K.

    1989-01-01

    An isotope of krypton, Kr86, has been combined with a mix of Ar, Ne, and N ions at the electron cyclotron resonance (ECR) source, at the Lawrence Berkeley Laboratory cyclotron, to provide rapid ion changeover in Single Event Phenomena (SEP) testing. The new technique has been proved out successfully by a recent Jet Propulsion Laboratory (JPL) test in which it was found that there was no measurable contamination from other isotopes.

  3. Note: Production of a mercury beam with an electron cyclotron resonance ion source

    SciTech Connect

    Vondrasek, R.; Pardo, R.; Scott, R.

    2013-11-15

    An electron cyclotron resonance ion source has been utilized to produce mercury beams with intensities of 4.5 eμA of {sup 202}Hg{sup 29+} and 3.0 eμA of {sup 202}Hg{sup 31+} from natural abundance mercury metal. The production technique relies on the evaporation of liquid mercury into the source plasma vacuum region and utilizes elemental mercury instead of a volatile organic compound as the neutral feed material.

  4. INSTRUMENTS AND METHODS OF INVESTIGATION: Plasma isotope separation based on ion cyclotron resonance

    NASA Astrophysics Data System (ADS)

    Dolgolenko, Dmitrii A.; Muromkin, Yurii A.

    2009-04-01

    Experiments that have been conducted in the USA, France, and Russia to investigate isotopically selective ion cyclotron resonance (ICR) as a tool for plasma isotope separation are analyzed. Because this method runs into difficulties at low values of the relative isotope mass difference ΔM/M, for some elements (for gadolinium, as an example) isotope separation still remains a problem. There are ways to solve it, however, as experimental results and theoretical calculations suggest.

  5. Validation of the load-resilient ion cyclotron resonance frequency antenna concept on Tore Supra plasmas

    NASA Astrophysics Data System (ADS)

    Vulliez, K.; Argouarch, A.; Bosia, G.; Berger-By, G.; Bremond, S.; Colas, L.; Lombard, G.; Mendes, A.; Millon, L.; Mollard, P.; Volpe, D.; Beaumont, B.; Bécoulet, A.; Clairet, F.; Ekedahl, A.; Elkhaldi, M.; Gunn, J.; Hoang, G. T.; Tore Supra Team

    2008-06-01

    In the framework of the ion cyclotron resonance frequency heating development at CEA Cadarache, a prototype antenna based on the load-resilient electrical layout foreseen for ITER has been built. This prototype was recently tested in Tore Supra. The ITER-like electrical scheme has been validated during fast perturbations at the edge plasma. Clear load resilience properties are reported. The main conclusions and consequences learned from the development of the ITER antenna are discussed.

  6. Design study of a 17.3 GHz electron cyclotron resonance (ECR) ion source at Louvain-la-Neuve

    SciTech Connect

    Standaert, L. Davin, F.; Loiselet, M.

    2014-02-15

    The Cyclotron Resources Center of the Louvain-la-Neuve University is developing a new electron cyclotron resonance ion source to increase the energy of the accelerated beam by injection of higher charge state ions into the cyclotron. The design of the source is based on a 17.3 GHz frequency and classical coils to produce the axial field. The field reaches 2 T at the injection side and 1.2 T at extraction. The total power consumption for the coils is limited to 80 kW. The design features of the source are presented.

  7. Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

    SciTech Connect

    Vondrasek, R.; Kutsaev, Sergey; Delahaye, P.; Maunoury, L.

    2012-11-15

    The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.

  8. Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source.

    PubMed

    Vondrasek, R; Delahaye, P; Kutsaev, Sergey; Maunoury, L

    2012-11-01

    The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a (252)Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species (143)Ba(27+). In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for (23)Na(7+) and 17.9% for (39)K(10+) were obtained injecting stable Na(+) and K(+) beams from a surface ionization source. PMID:23206054

  9. Five-Minute Solar Oscillations and Ion-Cyclotron Waves in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Guglielmi, A.; Potapov, A.; Dovbnya, B.

    2015-10-01

    We study the possible impact of the photospheric five-minute oscillations on the ion-cyclotron waves in the solar wind. We proceed from the assumption that the ion-cyclotron waves in the solar wind experience a modulation with a characteristic period of five minutes under the influence of Alfvén waves driven by photospheric motions. The theory presented in this article predicts a deep frequency modulation. This modulation is expected mainly from variations in the orientation of the interplanetary magnetic field lines, which, in turn, are caused by the Alfvén waves propagating from the Sun. To test the theoretical predictions, we analyzed records of the ultra-low-frequency (ULF) geoelectromagnetic waves to find the permanent quasi-monochromatic oscillations of natural origin in the Pc1 - 2 frequency band (0.1 - 5 Hz), the carrier frequency of which varies with time in a wide range. As a result, we found the so-called serpentine emission (SE), which was observed in Antarctica at the Vostok station near the South Geomagnetic Pole. The permanency, range of frequencies, and the deep frequency modulation of the SE correspond to the qualitative properties of ion-cyclotron waves in the solar wind. In the context of this work, one of the most important features of the SE is a clearly expressed five-minute modulation of the carrier frequency. We assume that we have found non-trivial manifestations of the solar five-minute oscillations on the Earth.

  10. Studies of electromagnetic ion cyclotron waves using AMPTE/CCE and Dynamics Explorer

    NASA Technical Reports Server (NTRS)

    Erlandson, Robert E.

    1993-01-01

    The principal activity during the past six months has involved the analysis of ion cyclotron waves recorded from DE-2 using the magnetic field experiment and electric field experiment. The results of this study have been published in the Geophysical Research Letters (GRL). The primary finding of this paper is that ion cyclotron waves were found to heat electrons, as observed in the DE-2 Langmuir probe data, through a Landau damping process. A second activity, which was started during the last six months, involves the study of large amplitude approximately one Hz electric and magnetic field oscillations recorded in the nightside auroral zone at substorm onset. Work is under way to determine the properties of these waves and investigate any association these waves may have with the substorm initiation process. A third activity under way involves a comprehensive study of ion cyclotron waves recorded at ionospheric altitudes by DE-2. This study will be an extension of the work reported in the GRL paper and will involve a larger sampling of wave events. This paper will focus on wave properties at ionospheric altitudes. A fourth activity involves a more in-depth analysis of the acceleration mechanisms and the resulting electron distributions based on the observations presented in the GRL paper.

  11. A revolutionary concept to improve the efficiency of ion cyclotron antennas

    SciTech Connect

    Milanesio, D. Maggiora, R.

    2014-06-15

    The successful design of an ion cyclotron (IC) antenna mainly relies on the capability of coupling high power to the plasma (MW), feature that is currently reached by allowing rather high voltages (tens of kV) on the unavoidable unmatched part of the feeding lines. This requirement is often responsible of arcs along the transmission lines and other unwanted phenomena, such as rectification discharges or hotspots, that considerably limit the usage of IC launchers. In this work, we suggest and describe a revolutionary approach based on high impedance surfaces, which allows to increase the antenna radiation efficiency and, hence, to highly reduce the imposed voltages to couple the same level of power to the plasma. High-impedance surfaces are periodic metallic structures (patches) displaced usually on top of a dielectric substrate and grounded by means of vertical posts usually embedded inside a dielectric, in a mushroom-like shape. In terms of working properties, high impedance surfaces are electrically thin in-phase reflectors, i.e., they present a high impedance, within a given frequency band, such that the image currents are in-phase with the currents of the antenna itself, thus determining a significant efficiency increase. While the usual design of a high impedance surface requires the presence of a dielectric layer, some alternative solutions can be realised in vacuum, taking advantage of double layers of metallic patches. After an introductory part on the properties of high impedance surfaces, this work documents both their design by means of numerical codes and their implementation on a scaled mock-up.

  12. Absorption of Fast Waves at Moderate to High Ion Cyclotron Harmonics on DIII-D

    SciTech Connect

    Pinsker, R.I.; Petty, C.C.; Prater, R.; Choi, M.; Porkolab, M.; Heidbrink, W.W.; Luo, Y.; Baity, F.W.; Murakami, M.; Fredd, E.; Hosea, J.C.; Harvey, R.W.; Smirnov, A.P.; Van Zeeland, M.A.

    2005-09-26

    The absorption of fast Alfven waves (FW) by ion cyclotron harmonic damping in the range of harmonics from fourth to eighth is studied theoretically and with experiments in the DIII-D tokamak. A formula for linear ion cyclotron absorption on Maxwellian ion species is used to estimate the single-pass damping for various cases of experimental interest. It is found that damping on fast ions from neutral beam injection can be significant even at the eighth harmonic if the fast ion beta and the background plasma density are both high enough. The predictions are tested in several L-mode experiments in DIII-D with FW power at 60 MHz and at 116 MHz. It is found that 4th and 5th harmonic absorption of the 60 MHz power on the beam ions can be quite strong, but 8th harmonic absorption of the 116 MHz power appears to be weaker than expected. Possible explanations of the discrepancy are discussed.

  13. Formation of multi-charged ion beams by focusing effect of mid-electrode on electron cyclotron resonance ion source

    SciTech Connect

    Imai, Youta Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2014-02-15

    We are constructing a tandem type electron cyclotron resonance ion source (ECRIS) and a beam line for extracting ion beams. The ion beam is extracted from the second stage by an accel-decel extraction system with a single-hole and the ion beam current on each electrode is measured. The total ion beam current is measured by a faraday cup downstream the extraction electrodes. We measure these currents as a function of the mid-electrode potential. We also change the gap length between electrodes and perform similar measurement. The behaviors of these currents obtained experimentally against the mid-electrode potential show qualitatively good agreement with a simple theoretical consideration including sheath potential effects. The effect of mid-electrode potential is very useful for decreasing the beam loss for enhancing ion beam current extracted from ECRIS.

  14. New tandem type ion source based on electron cyclotron resonance for universal source of synthesized ion beams

    SciTech Connect

    Kato, Yushi Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Kimura, Daiju; Kumakura, Sho; Imai, Youta; Nishiokada, Takuya; Sato, Fuminobu; Iida, Toshiyuki

    2014-02-15

    A new tandem type source has been constructed on the basis of electron cyclotron resonance (ECR) plasma for producing synthesized ion beams. We investigate feasibility and hope to realize the device which has wide range operation window in a single device to produce many kinds of ion beams based on ECR ion source (ECRIS). It is considered that ECR plasmas are necessary to be available to individual operations with different plasma parameters. Both of analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas. We describe construction of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source.

  15. Ion-cyclotron instability in current-carrying Lorentzian (kappa) and Maxwellian plasmas with anisotropic temperatures: A comparative study

    SciTech Connect

    Basu, B.; Grossbard, N. J.

    2011-09-15

    Current-driven electrostatic ion-cyclotron instability has so far been studied for Maxwellian plasma with isotropic and anisotropic temperatures. Since satellite-measured particle velocity distributions in space are often better modeled by the generalized Lorentzian (kappa) distributions and since temperature anisotropy is quite common in space plasmas, theoretical analysis of the current-driven, electrostatic ion-cyclotron instability is carried out in this paper for electron-proton plasma with anisotropic temperatures, where the particle parallel velocity distributions are modeled by kappa distributions and the perpendicular velocity distributions are modeled by Maxwellian distributions. Stability properties of the excited ion cyclotron modes and, in particular, their dependence on electron to ion temperature ratio and ion temperature anisotropy are presented in more detail. For comparison, the corresponding results for bi-Maxwellian plasma are also presented. Although the stability properties of the ion cyclotron modes in the two types of plasmas are qualitatively similar, significant quantitative differences can arise depending on the values of {kappa}{sub e} and {kappa}{sub i}. The comparative study is based on the numerical solutions of the respective linear dispersion relations. Quasilinear estimates of the resonant ion heating rates due to ion-cyclotron turbulence in the two types of plasma are also presented for comparison.

  16. Development of Electron Cyclotron Resonance Ion Source for Synthesis of Endohedral Metallofullerenes

    SciTech Connect

    Tanaka, K.; Muramatsu, M.; Uchida, T.; Hanajiri, T.; Yoshida, Y.; Biri, S.; Kitagawa, A.; Kato, Y.

    2008-11-03

    A new electron cyclotron resonance ion source (ECRIS) has been constructed for synthesis of endohedral metallofullerenes. The main purpose of the ion source is to produce new biological and medical materials. The design is based on ECRIS for production of multicharged ion beams with a traditional minimum-B magnetic field. An 8-10 GHz traveling wave tube (TWT) amplifier and a 2.45 GHz magnetron have been applied as microwave sources. Fullerene and metal vapor are introduced with a filament heating micro-oven and an induction heating oven, respectively. In preliminary ion-extraction test, Ar{sup +} is 54 {mu}A. Many broken fullerenes such as C{sub 58} and C{sub 56} are observed in fullerene ion beams.

  17. High power heating in the ion cyclotron range of frequencies in the Wisconsin Tokapole II

    SciTech Connect

    Biddle, A. P.; Sprott, J. C.

    1980-09-01

    Fast wave heating at the second, third, and fourth harmonics of the ion cyclotron resonance, and slow wave heating at the fundamental in a single ion species hydrogen plasma, are found to be in good agreement with warm plasma theory at rf power levels less than or equal to 130 kW. Ion heating is negligible off an eigenmode. Ion body temperatures are more than doubled to 75 eV from the 35 eV ohmically heated case with tails comprising 8% of the plasma at 320 eV. No deleterious effects except a non-disruptive 10% shortening of the discharge length caused by impurity influx are noted. A passive mode tracking technique allows approx. = 40% increase in power deposition in a passing eigenmode over that of a fixed frequency rf source. Ion temperatures are limited by charge exchange due to the < 50 eV central temperature and the small 13 cm radius current channel.

  18. Fourier transform ion cyclotron resonance (FT ICR) mass spectrometry: Theory and simulations.

    PubMed

    Nikolaev, Eugene N; Kostyukevich, Yury I; Vladimirov, Gleb N

    2016-01-01

    Fourier transform ion cyclotron resonance (FT ICR) mass spectrometer offers highest resolving power and mass accuracy among all types of mass spectrometers. Its unique analytical characteristics made FT ICR important tool for proteomics, metabolomics, petroleomics, and investigation of complex mixtures. Signal acquisition in FT ICR MS takes long time (up to minutes). During this time ion-ion interaction considerably affects ion motion and result in decreasing of the resolving power. Understanding of those effects required complicated theory and supercomputer simulations but culminated in the invention of the ion trap with dynamic harmonization which demonstrated the highest resolving power ever achieved. In this review we summarize latest achievements in theory and simulation of FT ICR mass spectrometers. PMID:24515872

  19. Toward a System-Based Approach to Electromagnetic Ion Cyclotron Waves in Earth's Magnetosphere

    NASA Astrophysics Data System (ADS)

    Gamayunov, K. V.; Engebretson, M. J.; Rassoul, H.

    2015-12-01

    We consider a nonlinear wave energy cascade from the low frequency range into the higher frequency domain of electromagnetic ion cyclotron (EMIC) wave generation as a possible source of seed fluctuations for EMIC wave growth due to the ion cyclotron instability in Earth's magnetosphere. The theoretical analysis shows that energy cascade from the Pc 4-5 frequency range (2-22 mHz) into the range of Pc 1-2 pulsations (0.1-5 Hz) is able to supply the level of seed fluctuations that guarantees growth of EMIC waves up to an observable level during one pass through the near equatorial region where the ion cyclotron instability takes place. We also analyze magnetic field data from the Polar and Van Allen Probes spacecraft to test this nonlinear mechanism. We restrict our analysis to magnetic spectra only. We do not analyze the third-order moment for total energy of the magnetic and velocity fluctuations, but judge whether a nonlinear energy cascade is present or whether it is not by only analyzing the appearance of power-law distributions in the low frequency part of the magnetic field spectra. While the power-law spectrum alone does not guarantee that a nonlinear cascade is present, the power-law distribution is a strong indication of the possible development of a nonlinear cascade. Our data analysis shows that a nonlinear energy cascade is indeed observed in both the outer and inner magnetosphere, and EMIC waves are growing from this nonthermal background. All the analyzed data are in good agreement with the theoretical model presented in this study. Overall, the results of this study support a nonlinear energy cascade in Earth's magnetosphere as a mechanism which is responsible for supplying seed fluctuating energy in the higher frequency domain where EMIC waves grow due to the ion cyclotron instability. Keywords: nonlinear energy cascade, ultra low frequency waves, electromagnetic ion cyclotron waves, seed fluctuationsAcknowledgments: This paper is based upon work

  20. PLT ion cyclotron range of frequencies heating program

    SciTech Connect

    Hosea, J.; Bell, R.; Budny, R.; Cavallo, A.; Cohen, S.; Colestock, P.; Hammett, G.; Hovey, J.; Hwang, D.; Kaita, R.

    1984-09-01

    Measurements of energetic ions, impurity influx, recycling, and Bernstein waves generated in the plasma core are described for ICRF heating in PLT. Such measurements are being used for several launchers in order to optimize rf power deposition and discharge conditions. Preparations are underway to extend operation to higher rf power levels (approx. 5 MW) for the best attainable PLT conditions to permit more reactor-relevant extrapolations.

  1. Effects of ion abundances on electromagnetic ion cyclotron wave growth rate in the vicinity of the plasmapause

    SciTech Connect

    Henning, F. D. Mace, R. L.

    2014-04-15

    Electromagnetic ion cyclotron (EMIC) waves in multi-ion species plasmas propagate in branches. Except for the branch corresponding to the heaviest ion species, which has only a resonance at its gyrofrequency, these branches are bounded below by a cutoff frequency and above by a resonant gyrofrequency. The condition for wave growth is determined by the thermal anisotropies of each ion species, j, which sets an upper bound, ω{sub j}{sup ∗}, on the wave frequency below which that ion species contributes positively to the growth rate. It follows that the relative positions of the cutoffs and the critical frequencies ω{sub j}{sup ∗} play a crucial role in determining whether a particular wave branch will be unstable. The effect of the magnetospheric ion abundances on the growth rate of each branch of the EMIC instability in a model where all the ion species have kappa velocity distributions is investigated by appealing to the above ideas. Using the variation of the cutoff frequencies predicted by cold plasma theory as a guide, optimal ion abundances that maximise the EMIC instability growth rate are sought. When the ring current is comprised predominantly of H{sup +} ions, all branches of the EMIC wave are destabilised, with the proton branch having the maximum growth rate. When the O{sup +} ion abundance in the ring current is increased, a decrease in the growth rate of the proton branch and cyclotron damping of the helium branch are observed. The oxygen branch, on the other hand, experiences an increase in the maximum growth rate with an increase in the O{sup +} ion abundance. When the ring current is comprised predominantly of He{sup +} ions, only the helium and oxygen branches of the EMIC wave are destabilised, with the helium branch having the maximum growth rate.

  2. Development of DRAGON electron cyclotron resonance ion source at Institute of Modern Physics

    SciTech Connect

    Lu, W.; Lin, S. H.; Xie, D. Z.; Zhang, X. Z.; Sha, S.; Zhang, W. H.; Cao, Y.; Guo, J. W.; Fang, X.; Guo, X. H.; Li, X. X.; Ma, H. Y.; Wu, Q.; Zhao, H. Y.; Ma, B. H.; Wang, H.; Zhu, Y. H.; Feng, Y. C.; Li, J. Y.; Li, J. Q.; and others

    2012-02-15

    A new room temperature electron cyclotron resonance (ECR) ion source, DRAGON, is under construction at IMP. DRAGON is designed to operate at microwaves of frequencies of 14.5-18 GHz. Its axial solenoid coils are cooled with evaporative medium to provide an axial magnetic mirror field of 2.5 T at the injection and 1.4 T at the extraction, respectively. In comparison to other conventional room temperature ECR ion sources, DRAGON has so far the largest bore plasma chamber of inner diameter of 126 mm with maximum radial fields of 1.4-1.5 T produced by a non-Halbach permanent sextupole magnet.

  3. The Spontaneous Loss of Coherence Catastrophe in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    PubMed Central

    Aizikov, Konstantin; Mathur, Raman; O’Connor, Peter B.

    2009-01-01

    The spontaneous loss of coherence catastrophe (SLCC) is a frequently observed, yet poorly studied, space-charge related effect in Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS). This manuscript presents an application of the filter diagonalization method (FDM) in the analysis of this phenomenon. The temporal frequency behavior reproduced by frequency shift analysis using the FDM shows the complex nature of the SLCC, which can be explained by a combination of factors occurring concurrently, governed by electrostatics and ion packet trajectories inside the ICR cell. PMID:19013078

  4. Demonstration of Effective Control of Fast-Ion-Stabilized Sawteeth by Electron-Cyclotron Current Drive

    NASA Astrophysics Data System (ADS)

    Lennholm, M.; Eriksson, L.-G.; Turco, F.; Bouquey, F.; Darbos, C.; Dumont, R.; Giruzzi, G.; Jung, M.; Lambert, R.; Magne, R.; Molina, D.; Moreau, P.; Rimini, F.; Segui, J.-L.; Song, S.; Traisnel, E.

    2009-03-01

    In a tokamak plasma, sawtooth oscillations in the central temperature, caused by a magnetohydrodynamic instability, can be partially stabilized by fast ions. The resulting less frequent sawtooth crashes can trigger unwanted magnetohydrodynamic activity. This Letter reports on experiments showing that modest electron-cyclotron current drive power, with the deposition positioned by feedback control of the injection angle, can reliably shorten the sawtooth period in the presence of ions with energies ≥0.5MeV. Certain surprising elements of the results are evaluated qualitatively in terms of existing theory.

  5. Fullerene-rare gas mixed plasmas in an electron cyclotron resonance ion source

    SciTech Connect

    Asaji, T. Ohba, T.; Uchida, T.; Yoshida, Y.; Minezaki, H.; Ishihara, S.; Racz, R.; Biri, S.; Kato, Y.

    2014-02-15

    A synthesis technology of endohedral fullerenes such as Fe@C{sub 60} has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C{sub 60} was reported. However, the yield was quite low, since most fullerene molecules were broken in the ECR plasma. We have adopted gas-mixing techniques in order to cool the plasma and then reduce fullerene dissociation. Mass spectra of ion beams extracted from fullerene-He, Ar or Xe mixed plasmas were observed with a Faraday cup. From the results, the He gas mixing technique is effective against fullerene destruction.

  6. Design of a new electron cyclotron resonance ion source at Oshima National College of Maritime Technology

    SciTech Connect

    Asaji, T. Hirabara, N.; Izumihara, T.; Nakamizu, T.; Ohba, T.; Nakamura, T.; Furuse, M.; Hitobo, T.; Kato, Y.

    2014-02-15

    A new electron cyclotron resonance ion/plasma source has been designed and will be built at Oshima National College of Maritime Technology by early 2014. We have developed an ion source that allows the control of the plasma parameters over a wide range of electron temperatures for material research. A minimum-B magnetic field composed of axial mirror fields and radial cusp fields was designed using mainly Nd-Fe-B permanent magnets. The axial magnetic field can be varied by three solenoid coils. The apparatus has 2.45 GHz magnetron and 2.5–6.0 GHz solid-state microwave sources.

  7. Diagnostics of a charge breeder electron cyclotron resonance ion source helium plasma with the injection of 23Na1+ ions

    NASA Astrophysics Data System (ADS)

    Tarvainen, O.; Koivisto, H.; Galatà, A.; Angot, J.; Lamy, T.; Thuillier, T.; Delahaye, P.; Maunoury, L.; Mascali, D.; Neri, L.

    2016-05-01

    This work describes the utilization of an injected 23Na1+ ion beam as a diagnostics of the helium plasma of a charge breeder electron cyclotron resonance ion source. The obtained data allows estimating the upper limit for the ion-ion collision mean-free path of the incident sodium ions, the lower limit of ion-ion collision frequencies for all charge states of the sodium ions and the lower limit of the helium plasma density. The ion-ion collision frequencies of high charge state ions are shown to be at least on the order of 1-10 MHz and the plasma density is estimated to be on the order of 1011 cm-3 or higher. The experimental results are compared to simulations of the 23Na1+ capture into the helium plasma. The results indicate that the lower breeding efficiency of light ions in comparison to heavier elements is probably due to different capture efficiencies in which the in-flight ionization of the incident 1 + ions plays a vital role.

  8. Ion-cyclotron waves at Jupiter - Possibility of detection by Ulysses

    NASA Technical Reports Server (NTRS)

    Mei, YI; Thorne, Richard M.; Horne, Richard B.

    1992-01-01

    Recent thermal plasma data and a computer code by Horne (1989) are employed to evaluate the linear-path-integrated gain of waves propagating through the Io to predict the Jovian plasma-wave environment. Estimates of the nonlinear saturation amplitudes are utilized with the thermal plasma data from two frequency bands to study the convective growth of the ion-cyclotron (IC) waves. Strong cyclotron resonant damping is theorized to prevent wave propagation to the lower latitudes, and the thermal plasma and cyclotron resonant energetic ions are expected to further confine the IC waves. L-mode waves below the O(+) gyrofrequency in the equatorial region of the torus are shown to inhabit an unstable region. The IC waves probably achieve nonlinear amplitudes regardless of plasma properties due to the rapid amplification in this region. It is suggested that the Ulysses data complicate the identification of the waves because the magnetometer is not adequately sensitive and because of the low frequency of the plasma-wave detector.

  9. Cyclotron mode frequencies and resonant absorption in multi-species ion plasmas

    SciTech Connect

    Affolter, M.; Anderegg, F.; Dubin, D. H. E.; Driscoll, C. F.

    2015-05-15

    Cyclotron mode frequencies are studied on trapped rigid-rotor multi-species ion plasmas. Collective effects and radial electric fields shift the mode frequencies away from the “bare” cyclotron frequencies 2πF{sub c}{sup (s)}≡(q{sub s}B/M{sub s}c) for each species s. These frequency shifts are measured on the distinct cyclotron modes (m=0,1, and 2) with cos(mθ) azimuthal dependence. We find that for radially uniform plasmas the frequency shifts corroborate a simple theory expression, in which collective effects enter only through the E × B rotation frequency f{sub E} and the species fraction δ{sub s}. The m = 1 center-of-mass mode is in agreement with a simple “clump” model. Additionally, ultra-cold ion plasmas exhibit centrifugal separation by mass, and additional frequency shifts are observed, in agreement with a more general theory.

  10. Wave Heating in Ion Cyclotron Ranges of Frequencies in RT-1

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Yoshida, Z.; Yano, Y.; Kawazura, Y.; Mushiake, T.; Saitoh, H.; Yamasaki, M.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2015-11-01

    The magnetosphere plasma device RT-1 has been developed for the studies on magnetosphere and advanced fusion plasmas. A levitated superconducting coil produces magnetic dipole fields that realize a high confinement state. The electron cyclotron resonance heating (ECRH) with 8.2 GHz and 50 kW produces the plasmas with hot electrons in a few ten keV range. We reported that the local electron beta exceeded 1 in RT-1 plasmas. In such situation, the ions still remain cold at a few ten eV. Heating ions is expected to access high ion beta state and to improve the plasma confinement theoretically. Therefore the ion cyclotron range of frequencies (ICRF) heating with 2-4 MHz and 10 kW is being prepared in RT-1. Based on the results of the TASK-WF2 code, the ∩ shape loop antenna was designed for a slow wave excitation, and was implemented in the RT-1. In the ICRF heating experiments, a base plasma was sustained by ECRH. We observed the clear increase in diamagnetic signals and impurity ion temperature (CIII) in helium plasmas at the neutral gas pressure of 3 mPa, if the ICRF power of 10 kW is comparable to the ECRH one. This result is the first time in a magnetosphere plasma device. The results related to the ICRF heating will be presented in detail. JSPS KAKENHI Grant Nos 23224014 and 24360384.

  11. Ion cyclotron range of frequencies heating of plasma with small impurity production

    DOEpatents

    Ohkawa, Tihiro

    1987-01-01

    Plasma including plasma ions is magnetically confined by a magnetic field. The plasma has a defined outer surface and is intersected by resonance surfaces of respective common ion cyclotron frequency of a predetermined species of plasma ions moving in the magnetic field. A radio frequency source provides radio frequency power at a radio frequency corresponding to the ion cyclotron frequency of the predetermined species of plasma ions moving in the field at a respective said resonance surface. RF launchers coupled to the radio frequency source radiate radio frequency energy at the resonance frequency onto the respective resonance surface within the plasma from a plurality of locations located outside the plasma at such respective distances from the intersections of the respective resonance surface and the defined outer surface and at such relative phases that the resulting interference pattern provides substantially null net radio frequency energy over regions near and including substantial portions of the intersections relative to the radio frequency energy provided thereby at other portions of the respective resonance surface within the plasma.

  12. Transverse acceleration of oxygen ions by electromagnetic ion cyclotron resonance with broad band left-hand polarized waves

    NASA Technical Reports Server (NTRS)

    Chang, T.; Crew, G. B.; Hershkowitz, N.; Jasperse, J. R.; Retterer, J. M.

    1986-01-01

    Central plasma sheet (CPS) ion conics are oxygen-dominated, with peak energies ranging from tens to hundreds of eV centered around pitch-angles between 115 and 130 degrees. Because of the lack of correlation between the CPS conics and the observed currents and/or electron beam-like structures, it is not likely that all of these conics are generated by interactions with electrostatic ion cyclotron waves or lower hybrid waves. Instead, it is suggested that the observed intense broad band electric field fluctuations in the frequency range between 0 and 100 Hz can be responsible for the transverse energization of the ions through cyclotron resonance heating with the left-hand polarized electromagnetic waves. This process is much more efficient for heating the oxygen ions than hydrogen ions, thus providing a plausible explanation of the oxygen dominance in CPS conics. Simple algebraic expressions are given from which estimates of conic energy and pitch angle can be easily calculated. This suggested mechanism can also provide some preheating of the oxygen ions in the boundary plasma sheet (BPS) where discrete aurorae form.

  13. Optimization of the ITER Ion Cyclotron Heating Antenna Array

    NASA Astrophysics Data System (ADS)

    Ryan, P. M.; Swain, D. W.; Carter, M. D.; Taylor, D. J.; Bosia, G.; D'Ippolito, D. A.; Myra, J. R.

    1996-11-01

    The present design of the ITER ICH antenna array comprises two poloidal by four toroidal current elements in each of four ports. Each current element forms a resonant double loop (RDL) with power fed to a pretuned matchpoint on the strap; the matching is accomplished using slow-wave transmission lines as adjustable shorted-stub tuners on either end of the current strap. The power requirement is 12.5 MW per port over the frequency range of 40--70 MHz, with extended operation to 80 MHz desirable. The antenna design optimization process includes strap shaping to minimize strap voltages and rf E-fields along B-field lines, (2) frame/Faraday shield geometry design to improve plasma coupling, wave spectrum directivity, and phase control, and (3) Faraday shield/bumper geometry to minimize rf sheath-induced structure heating and impurity generation.

  14. Surface-Induced Dissociation of Ions Produced by Matrix-Assisted Laser Desorption Ionization in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    SciTech Connect

    Laskin, Julia; Beck, Kenneth M.; Hache, John J.; Futrell, Jean H.

    2004-01-15

    Intermediate pressure matrix assisted laser ionization (MALDI) source was constructed and interfaced with a 6T Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially configured for surface-induced dissociation (SID) studies.

  15. The development of a room temperature electron cyclotron resonance ion source (Lanzhou electron cyclotron resonance ion source No. 4) with evaporative cooling technology at Institute of Modern Physics

    SciTech Connect

    Lu, W. Sun, L. T.; Qian, C.; Feng, Y. C.; Ma, H. Y.; Zhang, X. Z.; Ma, B. H.; Zhao, H. W.; Guo, J. W.; Fang, X.; Yang, Y.; Xiong, B.; Guo, S. Q.; Ruan, L.

    2015-04-15

    LECR4 (Lanzhou electron cyclotron resonance ion source No. 4) has been successfully constructed at IMP and has also been connected with the Low Energy Beam Transport (LEBT) and Radio Frequency Quadrupole (RFQ) systems. These source magnet coils are cooled through evaporative cooling technology, which is the first attempt with an ECR ion source in the world. The maximum mirror field is 2.5 T (with iron plug) and the effective plasma chamber volume is 1.2 l. It was designed to be operated at 18 GHz and aimed to produce intense multiple charge state heavy ion beams for the linear injector project SSC-Linac at IMP. In February 2014, the first analyzed beam at 18 GHz was extracted. During about three months’ commissioning, some outstanding results have been achieved, such as 1.97 emA of O{sup 6+}, 1.7 emA of Ar{sup 8+}, 1.07 emA of Ar{sup 9+}, and 118 euA of Bi{sup 28+}. The source has also successfully delivered O{sup 5+} and Ar{sup 8+} ion beams for RFQ commissioning in April 2014. This paper will give a brief overview of the design of LECR4. Then, the latest results of this source at 18 GHz will be presented.

  16. The development of a room temperature electron cyclotron resonance ion source (Lanzhou electron cyclotron resonance ion source No. 4) with evaporative cooling technology at Institute of Modern Physics.

    PubMed

    Lu, W; Sun, L T; Qian, C; Guo, J W; Fang, X; Feng, Y C; Yang, Y; Ma, H Y; Zhang, X Z; Ma, B H; Xiong, B; Guo, S Q; Ruan, L; Zhao, H W

    2015-04-01

    LECR4 (Lanzhou electron cyclotron resonance ion source No. 4) has been successfully constructed at IMP and has also been connected with the Low Energy Beam Transport (LEBT) and Radio Frequency Quadrupole (RFQ) systems. These source magnet coils are cooled through evaporative cooling technology, which is the first attempt with an ECR ion source in the world. The maximum mirror field is 2.5 T (with iron plug) and the effective plasma chamber volume is 1.2 l. It was designed to be operated at 18 GHz and aimed to produce intense multiple charge state heavy ion beams for the linear injector project SSC-Linac at IMP. In February 2014, the first analyzed beam at 18 GHz was extracted. During about three months' commissioning, some outstanding results have been achieved, such as 1.97 emA of O(6+), 1.7 emA of Ar(8+), 1.07 emA of Ar(9+), and 118 euA of Bi(28+). The source has also successfully delivered O(5+) and Ar(8+) ion beams for RFQ commissioning in April 2014. This paper will give a brief overview of the design of LECR4. Then, the latest results of this source at 18 GHz will be presented. PMID:25933849

  17. Cyclotron-resonance transmission through potassium in a perpendicular magnetic field: Effects of the charge-density wave

    NASA Astrophysics Data System (ADS)

    Park, Mi-Ae; Overhauser, A. W.

    1997-01-01

    Microwave transmission through potassium by Dunifer, Sambles, and Mace [J. Phys. Condens. Matter 1, 875 (1989)] in a perpendicular magnetic field shows five signals. They are Gantmakher-Kaner (GK) oscillations, conduction-electron-spin resonance, high-frequency oscillations, cyclotron resonance, and cyclotron-resonance subharmonics. Only the spin resonance has been successfully explained using a free-electron model. However, such a model predicts GK oscillations which are too large by several orders of magnitude. Lacueva and Overhauser [Phys. Rev. B 48, 16t935 (1993)] have shown that charge-density-wave (CDW) energy gaps which cut through the Fermi surface reduce the GK signal. CDW gaps also create a small Fermi-surface cylinder. The high-frequency oscillations were shown to result from Landau-level quantization in the cylinder. Recently we found that the anomalous microwave surface resistance, observed by Grimes and Kip [Phys. Rev. 132, 1991 (1963)], can be explained only if the cylinder axis is tilted ~45° with respect to the [110] crystal direction perpendicular to the surface. (Such a tilt was predicted by Giuliani and Overhauser [Phys. Rev. B 20, 1328 (1979)].) In this study we show that oscillatory motions, parallel to the field, of electrons in the tilted cylinder cause the cyclotron-resonance transmission. This signal and its subharmonics would be completely absent without the tilt. Consequently, four of the five transmission signals require a CDW broken symmetry.

  18. A Self-Consistent Model of the Interacting Ring Current Ions and Electromagnetic Ion Cyclotron Waves, Initial Results: Waves and Precipitating Fluxes

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.; Jordanova, V. K.; Krivorutsky, E. N.

    2002-01-01

    Initial results from a newly developed model of the interacting ring current ions and ion cyclotron waves are presented. The model is based on the system of two kinetic equations: one equation describes the ring current ion dynamics, and another equation describes wave evolution. The system gives a self-consistent description of the ring current ions and ion cyclotron waves in a quasilinear approach. These equations for the ion phase space distribution function and for the wave power spectral density were solved on aglobal magnetospheric scale undernonsteady state conditions during the 2-5 May 1998 storm. The structure and dynamics of the ring current proton precipitating flux regions and the ion cyclotron wave-active zones during extreme geomagnetic disturbances on 4 May 1998 are presented and discussed in detail.

  19. A second-order theory for transverse ion heating and momentum coupling due to electrostatic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Miller, Ronald H.; Winske, Dan; Gary, S. P.

    1992-01-01

    A second-order theory for electrostatic instabilities driven by counterstreaming ion beams is developed which describes momentum coupling and heating of the plasma via wave-particle interactions. Exchange rates between the waves and particles are derived, which are suitable for the fluid equations simulating microscopic effects on macroscopic scales. Using a fully kinetic simulation, the electrostatic ion cyclotron instability due to counterstreaming H(+) beams has been simulated. A power spectrum from the kinetic simulation is used to evaluate second-order exchange rates. The calculated heating and momentum loss from second-order theory is compared to the numerical simulation.

  20. The influence of dust particles on electromagnetic ion cyclotron waves in a bi-Lorentzian plasma

    SciTech Connect

    Venugopal, C.; Varughese, J.K.; Antony, S.; Anilkumar, C.P.; Renuka, G.

    1997-10-01

    The influence of dust particles on electromagnetic ion cyclotron (EMIC) waves, propagating parallel to the magnetic field, in a plasma where the hot ions are modelled by a bi-Lorentzian or Kappa distribution has been studied. The electrons and dust particles have been treated as cold. Expressions for the dispersion relations and growth/damping rates in both high- and low-{beta} plasmas have been derived. For the low-{beta} case temperature anisotropy is the source of instability in an electron{endash}ion plasma. This instability is strongly influenced by the temperature anisotropy of the hot ions and the charge and density of the dust particles; the instability increases with these parameters. However, in high-{beta} plasmas, the instability is driven by the dust. The growth rate increases with the charge on the dust; but with increasing dust densities the EMIC wave propagates almost freely. {copyright} {ital 1997 American Institute of Physics.}

  1. Progress in the development of an H- ion source for cyclotrons

    NASA Astrophysics Data System (ADS)

    Etoh, H.; Aoki, Y.; Mitsubori, H.; Arakawa, Y.; Kato, T.; Sakuraba, J.; Mitsumoto, T.; Yajima, S.; Okumura, Y.

    2015-04-01

    A multi-cusp DC H- ion source has been developed for cyclotrons in medical use. Beam optics of the H- ion beam is studied using a 2D beam trajectory code. The simulation results are compared with the experimental results obtained in the Mark I source, which has produced up to 16 mA H- ion beams. The optimum extraction voltages show good agreement between the calculation and the experimental results. A new ion source, Mark II source, is designed to achieve the next goal of producing an H- beam of 20 mA. The magnetic field configurations and the plasma electrode design are optimized for Cs-seeded operation. Primary electron trajectory simulation shows that primary electrons are confined well and the magnetic filter prevents the primary electrons from entering into the extraction region.

  2. The preliminary tests of the superconducting electron cyclotron resonance ion source DECRIS-SC2

    SciTech Connect

    Efremov, A.; Bekhterev, V.; Bogomolov, S.; Loginov, V.; Lebedev, A.; Yazvitsky, N.; Yakovlev, B.; Drobin, V.

    2012-02-15

    A new compact version of the ''liquid He-free'' superconducting ECR ion source, to be used as an injector of highly charged heavy ions for the MC-400 cyclotron, is designed and built at the Flerov Laboratory of Nuclear Reactions in collaboration with the Laboratory of High Energy Physics of JINR. The axial magnetic field of the source is created by the superconducting magnet and the NdFeB hexapole is used for the radial plasma confinement. The microwave frequency of 14 GHz is used for ECR plasma heating. During the first tests, the source shows a good enough performance for the production of medium charge state ions. In this paper, we will present the design parameters and the preliminary results with gaseous ions.

  3. Modelling of the ion cyclotron resonance heating scenarios for W7-X stellarator

    SciTech Connect

    Kazakov, Ye. O.

    2014-02-12

    The construction of the world largest superconducting stellarator Wendelstein 7-X (W7-X) has reached the final stage. One of the main scientific objectives of the W7-X project is to prove experimentally the predicted good confinement of high-energy ions. Ion cyclotron resonance heating (ICRH) system is considered to be installed in W7-X to serve as a localized source of high energy ions. ICRH heating scenarios relevant for hydrogen and deuterium phases of W7-X operation are summarized. The heating efficiency in ({sup 3}He)-H plasmas is qualitatively analyzed using a modified version of the 1D TOMCAT code able to account for stellarator geometry. The minority ion absorption is shown to be maximized at the helium-3 concentration ∼2% for the typical plasma and ICRH parameters to be available during the initial phase of W7-X.

  4. The preliminary tests of the superconducting electron cyclotron resonance ion source DECRIS-SC2.

    PubMed

    Efremov, A; Bekhterev, V; Bogomolov, S; Drobin, V; Loginov, V; Lebedev, A; Yazvitsky, N; Yakovlev, B

    2012-02-01

    A new compact version of the "liquid He-free" superconducting ECR ion source, to be used as an injector of highly charged heavy ions for the MC-400 cyclotron, is designed and built at the Flerov Laboratory of Nuclear Reactions in collaboration with the Laboratory of High Energy Physics of JINR. The axial magnetic field of the source is created by the superconducting magnet and the NdFeB hexapole is used for the radial plasma confinement. The microwave frequency of 14 GHz is used for ECR plasma heating. During the first tests, the source shows a good enough performance for the production of medium charge state ions. In this paper, we will present the design parameters and the preliminary results with gaseous ions. PMID:22380181

  5. Impurity Ions in a Plasma Produced by Electron Cyclotron Resonance Heating

    NASA Astrophysics Data System (ADS)

    Yonesu, Akira; Komori, Akio; Kawai, Yoshinobu

    1988-08-01

    The mechanism of the generation of impurity ions is experimentally evidenced in an electron cyclotron resonance (ECR) plasma produced with a copper Lisitano coil. It is shown that neutral copper particles are sputtered from the Lisitano coil by argon ions and are ionized by the collisions with electrons. The argon ions are accelerated by the ion sheath formed on the Lisitano coil surface, so that the plasma space potential plays an important role in producing the impurities. The impurity flux calculated by using plasma parameters and the sputtering yield of copper is found to be consistent with the observed value. The production of a pure ECR plasma is also attempted with an aluminum Lisitano coil which has a smaller sputtering yield than that of the copper Lisitano coil.

  6. Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source.

    PubMed

    Uchiyama, A; Ozeki, K; Higurashi, Y; Kidera, M; Komiyama, M; Nakagawa, T

    2016-02-01

    A RIKEN 18 GHz electron cyclotron resonance ion source (18 GHz ECRIS) is used as an external ion source at the Radioactive Ion Beam Factory (RIBF) accelerator complex to produce an intense beam of medium-mass heavy ions (e.g., Ca and Ar). In most components that comprise the RIBF, the control systems (CSs) are integrated by the Experimental Physics and Industrial Control System (EPICS). On the other hand, a non-EPICS-based system has hardwired controllers, and it is used in the 18 GHz ECRIS CS as an independent system. In terms of efficient and effective operation, the 18 GHz ECRIS CS as well as the RIBF CS should be renewed using EPICS. Therefore, we constructed an 18 GHz ECRIS CS by using programmable logic controllers with embedded EPICS technology. In the renewed system, an operational log system was developed as a new feature, for supporting of the 18 GHz ECRIS operation. PMID:26931940

  7. First results of the 2.45 GHz Oshima electron cyclotron resonance ion source.

    PubMed

    Asaji, T; Nakamura, T; Furuse, M; Hitobo, T; Uchida, T; Muramatsu, M; Kato, Y

    2016-02-01

    A new electron cyclotron resonance ion source has been constructed at Oshima College with a 2.45 GHz magnetron microwave source and permanent magnets employed as the main components. In addition, a solid-state power amplifier with a frequency range of 2.5-6.0 GHz was installed to study two-frequency plasma heating. Three solenoid coils were set up for adjusting the axial magnetic fields. Argon plasma generation and ion beam production have been conducted during the first year of operation. Ion current densities in the ECR plasma were measured using a biased disk. For 2.45 and 4.65 GHz two-frequency plasma heating, the ion density was approximately 1.5 times higher than that of 2.45 GHz single-frequency heating. PMID:26931948

  8. First results of the 2.45 GHz Oshima electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Asaji, T.; Nakamura, T.; Furuse, M.; Hitobo, T.; Uchida, T.; Muramatsu, M.; Kato, Y.

    2016-02-01

    A new electron cyclotron resonance ion source has been constructed at Oshima College with a 2.45 GHz magnetron microwave source and permanent magnets employed as the main components. In addition, a solid-state power amplifier with a frequency range of 2.5-6.0 GHz was installed to study two-frequency plasma heating. Three solenoid coils were set up for adjusting the axial magnetic fields. Argon plasma generation and ion beam production have been conducted during the first year of operation. Ion current densities in the ECR plasma were measured using a biased disk. For 2.45 and 4.65 GHz two-frequency plasma heating, the ion density was approximately 1.5 times higher than that of 2.45 GHz single-frequency heating.

  9. Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Uchiyama, A.; Ozeki, K.; Higurashi, Y.; Kidera, M.; Komiyama, M.; Nakagawa, T.

    2016-02-01

    A RIKEN 18 GHz electron cyclotron resonance ion source (18 GHz ECRIS) is used as an external ion source at the Radioactive Ion Beam Factory (RIBF) accelerator complex to produce an intense beam of medium-mass heavy ions (e.g., Ca and Ar). In most components that comprise the RIBF, the control systems (CSs) are integrated by the Experimental Physics and Industrial Control System (EPICS). On the other hand, a non-EPICS-based system has hardwired controllers, and it is used in the 18 GHz ECRIS CS as an independent system. In terms of efficient and effective operation, the 18 GHz ECRIS CS as well as the RIBF CS should be renewed using EPICS. Therefore, we constructed an 18 GHz ECRIS CS by using programmable logic controllers with embedded EPICS technology. In the renewed system, an operational log system was developed as a new feature, for supporting of the 18 GHz ECRIS operation.

  10. Progress in the development of an H{sup −} ion source for cyclotrons

    SciTech Connect

    Etoh, H. Aoki, Y.; Mitsubori, H.; Arakawa, Y.; Kato, T.; Sakuraba, J.; Mitsumoto, T.; Yajima, S.; Okumura, Y.

    2015-04-08

    A multi-cusp DC H{sup −} ion source has been developed for cyclotrons in medical use. Beam optics of the H{sup −} ion beam is studied using a 2D beam trajectory code. The simulation results are compared with the experimental results obtained in the Mark I source, which has produced up to 16 mA H{sup −} ion beams. The optimum extraction voltages show good agreement between the calculation and the experimental results. A new ion source, Mark II source, is designed to achieve the next goal of producing an H{sup −} beam of 20 mA. The magnetic field configurations and the plasma electrode design are optimized for Cs-seeded operation. Primary electron trajectory simulation shows that primary electrons are confined well and the magnetic filter prevents the primary electrons from entering into the extraction region.

  11. Particle precipitation due to ion-cyclotron instability in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Yahnin, Alexander

    Electromagnetic ion-cyclotron (EMIC) waves in the near-Earth equatorial magnetosphere effectively scatter energetic ions into the loss cone. As consequence, localized precipitation of energetic protons (LPEP) within the anisotropy zone is observed by low-orbiting satellites, like NOAA POES. Strong LPEP produces sub-oval proton auroras, which provide a two-dimensional image of the source region on the ionospheric screen. Here, we present some multipoint conjugate measurements confirming the relationship between LPEP and EMIC waves. Also, a conjugacy of LPEP and plasmapause structures is proved. In addition to LPEP, a wide (both in latitude and longitude) area of proton precipitation is often observed outside the plasmapause at sub-oval latitudes on the dayside. Both the case and statistical studies confirm that this dayside proton precipitation correlates with EMIC waves. Development of the ion-cyclotron instability on the dayside is evidently due to the enhanced transverse anisotropy of proton fluxes, which, in turn, is the result of the drift shell splitting. The anisotropy is “modulated” by the solar wind dynamic pressure. During magnetosphere compressions the precipitating proton flux increases, and flashes of the sub-oval proton aurora can be observed the dayside. It is suggested that EMIC waves also scatter relativistic electrons. Using the proton precipitation within the anisotropy zone as an indicator of the ion-cyclotron instability we performed a search of simultaneous relativistic electron precipitation (REP). We found that only 10 percent of REP events could be considered as potentially related to EMIC waves. These “EMIC wave related REP events” are observed only in the evening sector in connection with the plasmaspheric plume.

  12. Development of a miniature microwave electron cyclotron resonance plasma ion thruster for exospheric micro-propulsion

    NASA Astrophysics Data System (ADS)

    Dey, Indranuj; Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2015-12-01

    A miniature microwave electron cyclotron resonance plasma source [(discharge diameter)/(microwave cutoff diameter) < 0.3] has been developed at Kyushu University to be used as an ion thruster in micro-propulsion applications in the exosphere. The discharge source uses both radial and axial magnetostatic field confinement to facilitate electron cyclotron resonance and increase the electron dwell time in the volume, thereby enhancing plasma production efficiency. Performance of the ion thruster is studied at 3 microwave frequencies (1.2 GHz, 1.6 GHz, and 2.45 GHz), for low input powers (<15 W) and small xenon mass flow rates (<40 μg/s), by experimentally measuring the extracted ion beam current through a potential difference of ≅1200 V. The discharge geometry is found to operate most efficiently at an input microwave frequency of 1.6 GHz. At this frequency, for an input power of 8 W, and propellant (xenon) mass flow rate of 21 μg/s, 13.7 mA of ion beam current is obtained, equivalent to an calculated thrust of 0.74 mN.

  13. Theory and observations of electromagnetic ion cyclotron waves in Saturn's inner magnetosphere

    NASA Technical Reports Server (NTRS)

    Barbosa, D. D.

    1993-01-01

    High-resolution Voyager 1 magnetic field observations of Saturn's inner magnetosphere are examined for the presence of ULF waves. Quasi-circular left-hand polarized transverse oscillations are found in the near-equatorial region of 5-7 Rs with a wave period about 10 s and peak amplitude of about 2 nT. The wave is identified as the electromagnetic oxygen cyclotron mode occurring at a frequency just below the O(+) ion cyclotron frequency. A theoretical model of wave excitation based on gyroresonant coupling through a temperature anisotropy of O(+) pickup ions is developed which accounts for the principal features of the wave spectrum. It is hypothesized that wave-particle interactions provide a level of scattering commensurate with the weak pitch angle diffusion regime but nonetheless one that regulates and maintains a constant thermal anisotropy of ions along the magnetic field. Arguments are also presented that O(+) was the dominant thermal ion of the Dione-Tethys plasma torus at the time of the Pioneer 11 encounter the year previous to the Voyager 1 measurements.

  14. Development of a miniature microwave electron cyclotron resonance plasma ion thruster for exospheric micro-propulsion

    SciTech Connect

    Dey, Indranuj; Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2015-12-15

    A miniature microwave electron cyclotron resonance plasma source [(discharge diameter)/(microwave cutoff diameter) < 0.3] has been developed at Kyushu University to be used as an ion thruster in micro-propulsion applications in the exosphere. The discharge source uses both radial and axial magnetostatic field confinement to facilitate electron cyclotron resonance and increase the electron dwell time in the volume, thereby enhancing plasma production efficiency. Performance of the ion thruster is studied at 3 microwave frequencies (1.2 GHz, 1.6 GHz, and 2.45 GHz), for low input powers (<15 W) and small xenon mass flow rates (<40 μg/s), by experimentally measuring the extracted ion beam current through a potential difference of ≅1200 V. The discharge geometry is found to operate most efficiently at an input microwave frequency of 1.6 GHz. At this frequency, for an input power of 8 W, and propellant (xenon) mass flow rate of 21 μg/s, 13.7 mA of ion beam current is obtained, equivalent to an calculated thrust of 0.74 mN.

  15. Theory and observations of electromagnetic ion cyclotron waves in Saturn's inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Barbosa, D. D.

    1993-06-01

    High-resolution Voyager 1 magnetic field observations of Saturn's inner magnetosphere are examined for the presence of ULF waves. Quasi-circular left-hand polarized transverse oscillations are found in the near-equatorial region of 5-7 Rs with a wave period about 10 s and peak amplitude of about 2 nT. The wave is identified as the electromagnetic oxygen cyclotron mode occurring at a frequency just below the O(+) ion cyclotron frequency. A theoretical model of wave excitation based on gyroresonant coupling through a temperature anisotropy of O(+) pickup ions is developed which accounts for the principal features of the wave spectrum. It is hypothesized that wave-particle interactions provide a level of scattering commensurate with the weak pitch angle diffusion regime but nonetheless one that regulates and maintains a constant thermal anisotropy of ions along the magnetic field. Arguments are also presented that O(+) was the dominant thermal ion of the Dione-Tethys plasma torus at the time of the Pioneer 11 encounter the year previous to the Voyager 1 measurements.

  16. Development of a miniature microwave electron cyclotron resonance plasma ion thruster for exospheric micro-propulsion.

    PubMed

    Dey, Indranuj; Toyoda, Yuji; Yamamoto, Naoji; Nakashima, Hideki

    2015-12-01

    A miniature microwave electron cyclotron resonance plasma source [(discharge diameter)/(microwave cutoff diameter) < 0.3] has been developed at Kyushu University to be used as an ion thruster in micro-propulsion applications in the exosphere. The discharge source uses both radial and axial magnetostatic field confinement to facilitate electron cyclotron resonance and increase the electron dwell time in the volume, thereby enhancing plasma production efficiency. Performance of the ion thruster is studied at 3 microwave frequencies (1.2 GHz, 1.6 GHz, and 2.45 GHz), for low input powers (<15 W) and small xenon mass flow rates (<40 μg/s), by experimentally measuring the extracted ion beam current through a potential difference of ≅1200 V. The discharge geometry is found to operate most efficiently at an input microwave frequency of 1.6 GHz. At this frequency, for an input power of 8 W, and propellant (xenon) mass flow rate of 21 μg/s, 13.7 mA of ion beam current is obtained, equivalent to an calculated thrust of 0.74 mN. PMID:26724025

  17. Experiment study of an electron cyclotron resonant ion source based on a tapered resonance cavity

    SciTech Connect

    Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin; Komurasaki, Kimiya

    2013-12-15

    Electron cyclotron resonant plasma is one type of magnetised plasma generated by continuous microwave energy. It has the property of high degree of ionization and large volume at low gas pressure, which makes it useful for space propulsion and material processing. This article presents the experiment study of the plasma properties and ion beam extraction from an electron cyclotron resonant ion source based on a tapered resonance cavity. Optical emission spectroscopy based on a simple collisional radiation model was used for plasma diagnosis. Experiment results show that, at microwave power setting ranging from 7.06 to 17.40 W and mass flow rate ranging from 1 to 10 sccm, argon gas can be ionized. Ion beam of 109.1 mA from the ion source can be extracted at microwave power of 30 W, mass flow rate of 10 sccm, and accel voltage of 800 V. The diagnosed plasma temperature and density are 2.4–5.2 eV and 2 × 10{sup 16}–4.8 × 10{sup 17} m{sup −3}, respectively.

  18. Experiment study of an electron cyclotron resonant ion source based on a tapered resonance cavity

    NASA Astrophysics Data System (ADS)

    Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin; Komurasaki, Kimiya

    2013-12-01

    Electron cyclotron resonant plasma is one type of magnetised plasma generated by continuous microwave energy. It has the property of high degree of ionization and large volume at low gas pressure, which makes it useful for space propulsion and material processing. This article presents the experiment study of the plasma properties and ion beam extraction from an electron cyclotron resonant ion source based on a tapered resonance cavity. Optical emission spectroscopy based on a simple collisional radiation model was used for plasma diagnosis. Experiment results show that, at microwave power setting ranging from 7.06 to 17.40 W and mass flow rate ranging from 1 to 10 sccm, argon gas can be ionized. Ion beam of 109.1 mA from the ion source can be extracted at microwave power of 30 W, mass flow rate of 10 sccm, and accel voltage of 800 V. The diagnosed plasma temperature and density are 2.4-5.2 eV and 2 × 1016-4.8 × 1017 m-3, respectively.

  19. Low energy cyclotron for radiocarbon dating

    SciTech Connect

    Welch, J.J.

    1985-01-01

    The author built and tested a low energy cyclotron for radiocarbon dating similar to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. The author found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. The author shows how a conventional carbon negative ion source located outside the cyclotron magnet, would produce sufficient beam and provide for quick sample changing to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

  20. Spectral analysis of ICRF (Ion Cyclotron Range of Frequencies) wave field measurements in the Tara Central Cell

    SciTech Connect

    Wang, L.; Golovato, S.N.; Horne, S.F.

    1987-12-01

    A simple spectral analysis technique has been developed to analyse the digital signals from an array of magnetic probes for ICRF field measurements in the Tara Tandem Mirror central cell. The wave dispersion relations of both the applied ICRF and the Alfven Ion Cyclotron Instability have been studied and the waves have been identified as slow in cyclotron waves. The radial profiles of field amplitude and wave vectors were also generated. 9 refs., 10 figs.

  1. Preferential perpendicular acceleration of heavy ionospheric ions by interactions with electrostatic hydrogen cyclotron waves

    NASA Astrophysics Data System (ADS)

    Singh, N.; Schunk, R. W.; Sojka, J. J.

    1983-05-01

    Observations in recent years indicate the presence of energetic ions of ionospheric origin in various parts of the magnetosphere. These energetic ions have been found at all latitudes. Observations from the S3-3 satellite have made a great contribution toward an understanding of the energization of ionospheric ions. One of the most interesting observations is related to the finding that ion beams and electrostatic hydrogen cyclotron (EHC) waves are highly correlated and that they show an abrupt increase in their occurrence rate at an altitude of about 5000 km. A statistical survey of upward flowing ion (UFI) events occurring between 6000 and 8000 km has shown that the average energy of O(+) has a strong correlation with that of the H(+) ions. The present investigation has the objective to examine critically the energetics of UFI events in view of the theory of the interaction of a single coherent EHC wave with O(+), He(+), and H(+) ions. It is found that preferential acceleration of heavy ions occurs when such ions interact with an EHC wave.

  2. A study on vacuum aspects of electron cyclotron resonance ion source plasma

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Taki, G. S.; Mallick, C.; Bhandari, R. K.

    2008-05-01

    The electron cyclotron resonance (ECR) ion source is special type hot plasma machine where the high temperature electrons co-exist with multiply charge state ions and neutrals. A few years ago 6.4 GHz. ECR ion source (VEC-ECR) was developed indigenously at VECC. This multiply charged ion source is being used continuously to inject heavy ion beams into the cyclotron. Vacuum plays the major role in ECR ion source. The water cooled plasma chamber is made from an oxygen free high conductivity copper billet to meet the suitable surface condition for vacuum purpose. The entire volume of the ion source is pumped by two 900 1/s special type oil diffusion pumps to achieve 5×10-8 Torr. Usually main plasma chamber is pumped by the plasma itself. Moreover a few 1/s additional pumping speed is provided through extraction hole and pumping slot on the extraction electrode. A study has been carried out to understand the role of vacuum on the multiply charged heavy ion production process. Considering the ion production and loss criteria, it is seen that for getting Ar18+ better vacuum is essential for lower frequency operation. So, an ECR ion source can give better charge state current output operating at higher frequency and stronger confining magnetic field under a specific vacuum condition. The low pressure condition is essential to minimize charge exchange loss due to recombination of multiply charged ions with the neutral atoms. A fixed ratio of neutral to electron density must be maintained for optimizing a particular charge state in the steady state condition. As the electron density is proportional to square of the injected microwave frequency (nevpropf2) a particular operating pressure is essential for a specific charge state. From the study, it has been obtained that the production of Ar18+ ions needs a pressure ~ 9.6×10-8 Torr for 6.4 GHz. ECR ion source. It is also obtained that an ECR ion source, works at a particular vacuum level, can give better charge state

  3. Ion cyclotron resonance heating in the divertor tokamak ASDEX

    SciTech Connect

    Steinmetz, K.; Wesner, F.; Niedermeyer, H.; Becker, G.; Braun, F.; Eberhagen, A.; Fussmann, G.; Gehre, O.; Gernhardt, J.; v. Gierke, G.

    1986-05-01

    The main topics of ICRF investigations in ASDEX are the influence of the divertor on impurity production and transport in ICRH heated discharges, and the heating efficiency and plasma confinement in various scenarios (minority and harmonics regimes). The first experiments were conducted in November 1984 at 67 MHz, corresponding to second harmonic heating of a hydrogen plasma at B/sub 0/ = 2.2 T. A transmitted power of 2.5 MW has been reached so far, the total capability being 3 MW. A linear increase of the central electron and ion temperature with the rf power is observed in Ohmically preheated plasmas (..delta..T/sub e/approx.280 eV, ..delta..T/sub i/approx.500 eV, ..delta..W/sub p/approx.17 kJ at a power of 1.2 MW coupled to the plasma and n-bar/sub e/ = 3.5 x 10/sup 13/ cm/sup -3/). The total radiation increases linearly with the power, too, and the ratio P/sub rad//P/sub tot/approx.0.35 stays approximately constant. However, first investigations indicate that with a divertor, ICRF operation is also accompanied by a significant increase in impurity production. The presence of neutral beam injection in addition to ICRH clearly enhances the absorption of the wave energy from about 50% to up to 90% with respect to the coupled power. With neutral beam injection (P/sub NI/< or =3.5 MW) the increment of the plasma energy content due to ICRH (P/sub rf/< or =2 MW) is found to be almost twice as large as in case OH+ICRH. Global heating efficiencies of up to 3 x 10/sup 13/ eV/kW cm/sup 3/ compare quite well with other ICRH experiments. First observations indicate a degradation of plasma confinement with ICRH to values in between L-type and OH confinement.

  4. Production of beams from solid materials at Center for Nuclear Study electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Ohshiro, Y.; Yamaka, S.; Watanabe, S.; Kobayashi, K.; Kotaka, Y.; Nishimura, M.; Kase, M.; Muto, H.; Yamaguchi, H.; Shimoura, S.

    2014-02-01

    Two methods for the feed of vapor from solid materials in the Center for Nuclear Study ECR ion source are described. A rod placed near the wall of the plasma chamber, operating up to a melting point of 2600 °C, has been used for CaO, SiO2, and FeO. An oven with a number of openings, operating up to 800 °C, has been used for P2O5, Li, and S. Typical ion beam intensities of 7Li2+, 6Li3+, 40Ca12+, and 56Fe15+ are achieved 280, 75, 28, and 7 eμA, respectively. High intensity heavy ion beams are stably supplied into the azimuthally varying field cyclotron.

  5. Electron energy distribution function by using probe method in electron cyclotron resonance multicharged ion source

    SciTech Connect

    Kumakura, Sho Kurisu, Yosuke; Kimura, Daiju; Yano, Keisuke; Imai, Youta; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2014-02-15

    We are constructing a tandem type electron cyclotron resonance (ECR) ion source (ECRIS). High-energy electrons in ECRIS plasma affect electron energy distribution and generate multicharged ion. In this study, we measure electron energy distribution function (EEDF) of low energy region (≦100 eV) in ECRIS plasma at extremely low pressures (10{sup −3}–10{sup −5} Pa) by using cylindrical Langmuir probe. From the result, it is found that the EEDF correlates with the electron density and the temperature from the conventional probe analysis. In addition, we confirm that the tail of EEDF spreads to high energy region as the pressure rises and that there are electrons with high energy in ECR multicharged ion source plasma. The effective temperature estimated from the experimentally obtained EEDF is larger than the electron temperature obtained from the conventional method.

  6. Roadmap for the design of a superconducting electron cyclotron resonance ion source for Spiral2

    SciTech Connect

    Thuillier, T.; Angot, J.; Lamy, T.; Peaucelle, C.

    2012-02-15

    A review of today achieved A/Q = 3 heavy ions beams is proposed. The daily operation A/Q = 3 ion beam intensities expected at Spiral2 are at the limit or above best record 3rd generation electron cyclotron resonance ion source (ECRIS) intensities. The necessity to build a new fully superconducting to fulfill these requirements is outlined. A discussion on the volume of the future source is proposed and the minimum value of 12 liters is derived. An analysis of the x-ray absorption superconducting ECRIS is presented based on VENUS experimental data and geometry. This study underlines the necessity to include a complete x-ray study at the time of source conception. The specifications foreseen for the new ECRIS are presented, followed with the roadmap for the design.

  7. Mode conversion and absorption of fast waves at high ion cyclotron harmonics in inhomogeneous magnetic fields

    SciTech Connect

    Cho, Suwon; Kwak, Jong-Gu

    2014-04-15

    The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where λ{sub i}=k{sub ⊥}{sup 2}ρ{sub i}{sup 2}/2≳1 (where k{sub ⊥} is the perpendicular wave number and ρ{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.

  8. Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS.

    PubMed

    Thomae, R; Conradie, J; Fourie, D; Mira, J; Nemulodi, F; Kuechler, D; Toivanen, V

    2016-02-01

    At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented. PMID:26931949

  9. Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

    NASA Astrophysics Data System (ADS)

    Thomae, R.; Conradie, J.; Fourie, D.; Mira, J.; Nemulodi, F.; Kuechler, D.; Toivanen, V.

    2016-02-01

    At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.

  10. Observation of ion-cyclotron-frequency mode-conversion flow drive in tokamak plasmas.

    PubMed

    Lin, Y; Rice, J E; Wukitch, S J; Greenwald, M J; Hubbard, A E; Ince-Cushman, A; Lin, L; Porkolab, M; Reinke, M L; Tsujii, N

    2008-12-01

    Strong toroidal flow (Vphi) and poloidal flow (Vtheta) have been observed in D-3He plasmas with ion cyclotron range of frequencies (ICRF) mode-conversion (MC) heating on the Alcator C-Mod tokamak. The toroidal flow scales with the rf power Prf (up to 30 km/s per MW), and is significantly larger than that in ICRF minority heated plasmas at the same rf power or stored energy. The central Vphi responds to Prf faster than the outer regions, and the Vphi(r) profile is broadly peaked for r/a < or =0.5. Localized (0.3 < or = r/a < or =0.5) Vtheta appears when Prf > or =1.5 MW and increases with power (up to 0.7 km/s per MW). The experimental evidence together with numerical wave modeling suggests a local flow drive source due to the interaction between the MC ion cyclotron wave and 3He ions. PMID:19113561

  11. Consequences of the Ion Cyclotron Instability in the Inner Magnetospheric Plasma

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2011-01-01

    The inner magnetospheric plasma is a very unique composition of different plasma particles and waves. Among these plasma particles and waves are Ring Current (RC) particles and Electromagnetic Ion Cyclotron (EMIC) waves. The RC is the source of free energy for the EMIC wave excitation provided by a temperature anisotropy of RC ions, which develops naturally during inward E x B convection from the plasma sheet. The cold plasmasphere, which is under the strong influence of the magnetospheric electric field, strongly mediates the RC-EMIC waves-coupling process, and ultimately becomes part of the particle and energy interplay, generated by the ion cyclotron instability of the inner magnetosphere. On the other hand, there is a strong influence of the RC on the inner magnetospheric electric and magnetic field configurations and these configurations, in turn, are important to RC dynamics. Therefore, one of the biggest needs for inner magnetospheric plasma physics research is the continued progression toward a coupled, interconnected system, with the inclusion of nonlinear feedback mechanisms between the plasma populations, the electric and magnetic fields, and plasma waves.

  12. High Throughput Proteomics Using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    SciTech Connect

    Qian, Weijun; Camp, David G.; Smith, Richard D.

    2004-06-01

    The advent of high throughput proteomics technology for global detection and quantitation of proteins creates new opportunities and challenges for those seeking to gain greater understanding of cellular machinery. Here, we review recent advances in high-resolution capillary liquid chromatography coupled to Fourier transform ion cyclotron resonance (FTICR) mass spectrometry along with its potential application to high throughput proteomics. These technological advances combined with quantitative stable isotope labeling methodologies provide powerful tools for expanding our understanding of biology at the system-level.

  13. ^238U Fission Ion Chamber for Neutron Dosimetry at the 88-Inch Cyclotron

    NASA Astrophysics Data System (ADS)

    Wilson, Brent; McMahan, Peggy; Barquest, Brad; Johnson, Mike

    2007-10-01

    Efficiency measurements have been conducted for a commercial ^238U fission ion chamber, to be used for neutron dosimetry at the 88-Inch Cyclotron at LBNL. Fast, quasi-monoenergetic neutrons in the energy range of 5 to 30 MeV are under development at the facility through deuteron break-up, for radiation effects testing and cross-section measurements for a variety of applications. Through comparisons with absolute fluxes obtained using activation foils, and energy spectra obtained using the time-of-flight method, efficiency for both monoenergetic and white spectrum neutrons can be calculated.

  14. Atmospheric Pressure Ionization Permanent Magnet Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    PubMed Central

    Vilkov, Andrey N.; Gamage, Chaminda M.; Misharin, Alexander S.; Doroshenko, Vladimir M.; Tolmachev, Dmitry A.; Tarasova, Irina A.; Kharybin, Oleg N.; Novoselov, Konstantin P.; Gorshkov, Michael V.

    2007-01-01

    A new Fourier Transform Ion Cyclotron Resonance mass spectrometer based on a permanent magnet with an atmospheric pressure ionization source was designed and constructed. A mass resolving power (full-width-at-half-maximum) of up to 80,000 in the electron ionization mode and 25,000 in the electrospray mode was obtained. Also, a mass measurement accuracy at low-ppm level has been demonstrated for peptide mixtures in a mass range of up to 1,200 m/z in the isotopically resolved mass spectra. PMID:17587594

  15. Progress in high-temperature oven development for 28 GHz electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Ohnishi, J.; Higurashi, Y.; Nakagawa, T.

    2016-02-01

    We have been developing a high-temperature oven using UO2 in the 28 GHz superconducting electron cyclotron resonance ion source at RIKEN since 2013. A total of eleven on-line tests were performed. The longest operation time in a single test was 411 h, and the consumption rate of UO2 was approximately 2.4 mg/h. In these tests, we experienced several problems: the ejection hole of a crucible was blocked with UO2 and a crucible was damaged because of the reduction of tungsten strength at high temperature. In order to solve these problems, improvements to the crucible shape were made by simulations using ANSYS.

  16. Study of pulsed electron cyclotron resonance ion source plasma near breakdown: The preglow

    SciTech Connect

    Thuillier, T.; Lamy, T.; Latrasse, L.; Izotov, I. V.; Sidorov, A. V.; Skalyga, V. A.; Zorin, V. G.; Marie-Jeanne, M.

    2008-02-15

    A careful study of pulsed mode operation of the PHOENIX electron cyclotron resonance (ECR) ion source has clearly demonstrated the reality of an unexpected transient current peak, occurring at the very beginning of the plasma breakdown. This regime was named the preglow, as an explicit reference to the afterglow occurring at the microwave pulse end. After the transient preglow peak, the plasma regime relaxes to the classical steady state one. Argon preglow experiments performed at LPSC are presented. A theoretical model of ECR gas breakdown in a magnetic trap, developed at IAP, showing satisfactory agreement with the experimental results is suggested.

  17. Stochastic Growth of Ion Cyclotron And Mirror Waves In Earth's Magnetosheath

    NASA Technical Reports Server (NTRS)

    Cairns, Iver H.; Grubits, K. A.

    2001-01-01

    Electromagnetic ion cyclotron and mirror waves in Earth's magnetosheath are bursty, have widely variable fields, and are unexpectedly persistent, properties difficult to reconcile with uniform secular growth. Here it is shown for specific periods that stochastic growth theory (SGT) quantitatively accounts for the functional form of the wave statistics and qualitatively explains the wave properties. The wave statistics are inconsistent with uniform secular growth or self-organized criticality, but nonlinear processes sometimes play a role at high fields. The results show SGT's relevance near marginal stability and suggest that it is widely relevant to space and astrophysical plasmas.

  18. On the preferred source location for the convective amplification of ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Horne, Richard B.; Thorne, Richard M.

    1993-01-01

    The propagation, growth, and absorption of electromagnetic ion cyclotron waves (EMICs) in the Pc1 range are studied using the HOTRAY ray tracing program for a realistic distribution of thermal plasma (H+, He+, O+), which is assumed to be in diffusive equilibrium inside the plasmasphere and collisionless in the low-density region outside the plasmapause. It is demonstrated that there are two principal source regions for the growth of EMIC waves. The theoretical results are related to the most recent satellite and ground-based observations.

  19. Theoretical analysis of the EAST 4-strap ion cyclotron range of frequency antenna with variational theory

    NASA Astrophysics Data System (ADS)

    Zhang, Jia-Hui; Zhang, Xin-Jun; Zhao, Yan-Ping; Qin, Cheng-Ming; Chen, Zhao; Yang, Lei; Wang, Jian-Hua

    2016-08-01

    A variational principle code which can calculate self-consistently currents on the conductors is used to assess the coupling characteristic of the EAST 4-strap ion cyclotron range of frequency (ICRF) antenna. Taking into account two layers of antenna conductors without lateral frame but with slab geometry, the antenna impedances as a function of frequency and the structure of RF field excited inside the plasma in various phasing cases are discussed in this paper. Project supported by the National Magnetic Confinement Fusion Science Program, China (Grant No. 2015GB101001) and the National Natural Science Foundation of China (Grant Nos. 11375236 and 11375235).

  20. Decay of electrostatic hydrogen cyclotron waves into ion acoustic modes in auroral field lines

    NASA Astrophysics Data System (ADS)

    Bergmann, R.; Hudson, M. K.

    1987-03-01

    The coherent three-wave decay of a linearly unstable electrostatic hydrogen cyclotron (EHC) wave into stable EHC and ion acoustic modes is considered. The general problem of the three weakly interacting electrostatic normal modes in a Maxwellian plasma is discussed. EHC is examined in a fluid description, and the results are used to guide a similar study in a Vlasov plasma system intended to model the aurora acceleration region parameters. The time dependence of the decay in a simple three-wave interaction is presented in order to show how wave saturation can arise.

  1. Investigation of electrostatic waves in the ion cyclotron range of frequencies in L-4 and ACT-1

    SciTech Connect

    Ono, Masayuki.

    1993-05-01

    Electrostatic waves in the ion cyclotron range of frequencies (ICRF) were studied in the Princeton L-4 and ACT-1 devices for approximately ten years, from 1975 to 1985. The investigation began in the L-4 linear device, looking for the parametric excitation of electrostatic ion cyclotron waves in multi-ion-species plasmas. In addition, this investigation verified multi-ion-species effects on the electrostatic ion cyclotron wave dispersion religion including the ion-ion hybrid resonance. Finite-Larmor-radius modification of the wave dispersion relation was also observed, even for ion temperatures of T[sub i] [approx] 1/40 eV. Taking advantage of the relatively high field and long device length of L-4, the existence of the cold electrostatic ion cyclotron wave (CES ICW) was verified. With the arrival of the ACT-1 toroidal device, finite-Larmor-radius (FLR) waves were studied in a relatively collisionless warm-ion hydrogen plasma. Detailed investigations of ion Bernstein waves (IBW) included the verification of mode-transformation in their launching, their wave propagation characteristics, their absorption, and the resulting ion heating. This basic physics activity played a crucial role in developing a new reactor heating concept termed ion Bernstein wave heating. Experimental research in the lower hybrid frequency range confirmed the existence of FLR effects near the lower hybrid resonance, predicted by Stix in 1965. In a neon plasma with a carefully placed phased wave exciter, the neutralized ion Bernstein wave was observed for the first time. Using a fastwave ICRF antenna, two parasitic excitation processes for IBW -- parametric instability and density-gradient-driven excitation -- were also discovered. In the concluding section of this paper, a possible application of externally launched electrostatic waves is suggested for helium ash removal from fusion reactor plasmas.

  2. Investigation of electrostatic waves in the ion cyclotron range of frequencies in L-4 and ACT-1

    SciTech Connect

    Ono, Masayuki

    1993-05-01

    Electrostatic waves in the ion cyclotron range of frequencies (ICRF) were studied in the Princeton L-4 and ACT-1 devices for approximately ten years, from 1975 to 1985. The investigation began in the L-4 linear device, looking for the parametric excitation of electrostatic ion cyclotron waves in multi-ion-species plasmas. In addition, this investigation verified multi-ion-species effects on the electrostatic ion cyclotron wave dispersion religion including the ion-ion hybrid resonance. Finite-Larmor-radius modification of the wave dispersion relation was also observed, even for ion temperatures of T{sub i} {approx} 1/40 eV. Taking advantage of the relatively high field and long device length of L-4, the existence of the cold electrostatic ion cyclotron wave (CES ICW) was verified. With the arrival of the ACT-1 toroidal device, finite-Larmor-radius (FLR) waves were studied in a relatively collisionless warm-ion hydrogen plasma. Detailed investigations of ion Bernstein waves (IBW) included the verification of mode-transformation in their launching, their wave propagation characteristics, their absorption, and the resulting ion heating. This basic physics activity played a crucial role in developing a new reactor heating concept termed ion Bernstein wave heating. Experimental research in the lower hybrid frequency range confirmed the existence of FLR effects near the lower hybrid resonance, predicted by Stix in 1965. In a neon plasma with a carefully placed phased wave exciter, the neutralized ion Bernstein wave was observed for the first time. Using a fastwave ICRF antenna, two parasitic excitation processes for IBW -- parametric instability and density-gradient-driven excitation -- were also discovered. In the concluding section of this paper, a possible application of externally launched electrostatic waves is suggested for helium ash removal from fusion reactor plasmas.

  3. First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator

    NASA Astrophysics Data System (ADS)

    Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong; Kim, Seong Jun; Ok, Jung-Woo; Yoon, Jang-Hee; Kim, Hyun Gyu; Shin, Chang Seouk; Hong, Jonggi; Bahng, Jungbae; Won, Mi-Sook

    2016-02-01

    The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted into the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project.

  4. First results of 28 GHz superconducting electron cyclotron resonance ion source for KBSI accelerator.

    PubMed

    Park, Jin Yong; Lee, Byoung-Seob; Choi, Seyong; Kim, Seong Jun; Ok, Jung-Woo; Yoon, Jang-Hee; Kim, Hyun Gyu; Shin, Chang Seouk; Hong, Jonggi; Bahng, Jungbae; Won, Mi-Sook

    2016-02-01

    The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion for the linear accelerator at KBSI (Korea Basic Science Institute). The objective of this study is to generate fast neutrons with a proton target via a p(Li,n)Be reaction. The design and fabrication of the essential components of the ECR ion source, which include a superconducting magnet with a liquid helium re-condensed cryostat and a 10 kW high-power microwave, were completed. The waveguide components were connected with a plasma chamber including a gas supply system. The plasma chamber was inserted into the warm bore of the superconducting magnet. A high voltage system was also installed for the ion beam extraction. After the installation of the ECR ion source, we reported the results for ECR plasma ignition at ECRIS 2014 in Russia. Following plasma ignition, we successfully extracted multi-charged ions and obtained the first results in terms of ion beam spectra from various species. This was verified by a beam diagnostic system for a low energy beam transport system. In this article, we present the first results and report on the current status of the KBSI accelerator project. PMID:26931935

  5. Cyclotron resonances of ions with obliquely propagating waves in coronal holes and the fast solar wind

    NASA Astrophysics Data System (ADS)

    Hollweg, Joseph V.; Markovskii, S. A.

    2002-06-01

    There is a growing consensus that cyclotron resonances play important roles in heating protons and ions in coronal holes where the fast solar wind originates and throughout interplanetary space as well. Most work on cyclotron resonant interactions has concentrated on the special, but unrealistic, case of propagation along the ambient magnetic field, B0, because of the great simplification it gives. This paper offers a physical discussion of how the cyclotron resonances behave when the waves propagate obliquely to B0. We show how resonances at harmonics of the cyclotron frequency come about, and how the physics can be different depending on whether E⊥ is in or perpendicular to the plane containing k and B0 (k is wave vector, and E⊥ is the component of the wave electric field perpendicular to B0). If E⊥ is in the k-B0 plane, the resonances are analogous to the Landau resonance and arise because the particle tends to stay in phase with the wave during the part of its orbit when it is interacting most strongly with E⊥. If E⊥ is perpendicular to the k-B0 plane, then the resonances depend on the fact that the particle is at different positions during the parts of its orbit when it is interacting most strongly with E⊥. Our main results are our equations (10), (11), and (13) for the secular rate of energy gain (or loss) by a resonant particle and the unfamiliar result that ions can resonate with a purely right-hand circularly polarized wave if the propagation is oblique. We conclude with some speculations about the origin of highly obliquely propagating ion resonant waves in the corona and solar wind. We point out that there are a number of instabilities that may generate such waves locally in the corona and solar wind.

  6. Results with the superconducting electron cyclotron resonance ion source VENUS (invited)

    NASA Astrophysics Data System (ADS)

    Lyneis, C. M.; Leitner, D.; Abbott, S. R.; Dwinell, R. D.; Leitner, M.; Silver, C. S.; Taylor, C.

    2004-05-01

    During the last year, the VENUS electron cyclotron resonance (ECR) ion source was commissioned at 18 GHz and preparations for 28 GHz operation, which is set to begin early in 2004, are now underway. The goal of the VENUS ECR ion source project as the RIA research and development injector is the production of 240 eμA of U30+, a high current medium charge state beam. On the other hand, as an injector ion source for the 88-Inch Cyclotron the design objective is the production of 5 eμA of U48+, a low current, very high charge state beam. During the commissioning phase with 18 GHz, tests with various gases and recently metals have been performed with up to 2000 W rf power and the performance is very promising. For example, 1100 eμA of O6+, 180 eμA of Ar12+, 150 eμA of Xe20+, and 100 eμA of Bi24+ were produced in the early commissioning phase, ranking VENUS among the currently highest performance 18 GHz ECR ion sources. The emittance of the beams produced at 18 GHz was measured with a two axis emittance scanner. In FY04 a 10 kW, 28 GHz gyrotron system will be added, which will enable VENUS to reach full performance. The performance of the VENUS ion source, low energy beam transport and its closed loop cryogenic system are described in the article. Recently, a high temperature axial oven has been installed in the source and the first results on metal beams such as bismuth are given. The design of the 28 GHz, 10 kW gyrotron system will also be described.

  7. Development of an Accelerator Mass Spectrometer based on a Cyclotron

    SciTech Connect

    Kim, Dogyun; Bhang, Hyeongchan; Kim, Jongwon

    2011-12-13

    An accelerator mass spectrometer based on a cyclotron has been developed, and a prototype of the injection beam line has been constructed. Mass resolution of the cyclotron is designed to be over 4000. A sawtooth RF buncher in the beam line and a flat-topping RF system for the cyclotron were utilized to enhance beam transmission efficiency, which is a primary factor for improvement compared to previous cyclotron mass spectrometers. The injection beam line comprises an ion source, Einzel lens, RF buncher, 90 deg. dipole magnet and a slit box containing beam diagnostic devices. A carbon beam was measured at the location of the slit box, and beam phase spaces will be measured. The design of a cyclotron magnet was done, and orbit tracking was carried out using cyclotron optics codes. A scheme of radial injection was chosen to place a beam on the equilibrium orbit of the cyclotron. The injection scheme will be optimized after the beam measurements are completed.

  8. Stability of relativistic electron trapping by strong whistler or electromagnetic ion cyclotron waves

    NASA Astrophysics Data System (ADS)

    Artemyev, A. V.; Mourenas, D.; Agapitov, O. V.; Vainchtein, D. L.; Mozer, F. S.; Krasnoselskikh, V.

    2015-08-01

    In the present paper, we investigate the trapping of relativistic electrons by intense whistler-mode waves or electromagnetic ion cyclotron waves in the Earth's radiation belts. We consider the non-resonant impact of additional, lower amplitude magnetic field fluctuations on the stability of electron trapping. We show that such additional non-resonant fluctuations can break the adiabatic invariant corresponding to trapped electron oscillations in the effective wave potential. This destruction results in a diffusive escape of electrons from the trapped regime of motion and thus can lead to a significant reduction of the efficiency of electron acceleration. We demonstrate that when energetic electrons are trapped by intense parallel or very oblique whistler-mode waves, non-resonant magnetic field fluctuations in the whistler-mode frequency range with moderate amplitudes around 3 -15 pT (much less intense than the primary waves) can totally disrupt the trapped motion. However, the trapping of relativistic electrons by electromagnetic ion cyclotron waves is noticeably more stable. We also discuss how the proposed approach can be used to estimate the effects of wave amplitude modulations on the motion of trapped particles.

  9. Equator-S observations of ion cyclotron waves outside the dawnside magnetopause

    NASA Astrophysics Data System (ADS)

    Dunlop, M. W.; Lucek, E. A.; Kistler, L. M.; Cargill, P.; Balogh, A.; Baumjohann, W.

    2002-09-01

    The Equator-S satellite often remained close to the magnetopause for long periods on the morningside of the magnetosphere. The combination of this coverage, slow magnetopause crossings (˜1-2 km/s), and high-resolution (64-128 Hz) magnetic field data allows very close inspection of the region adjacent to the magnetopause. Strong signatures consistent with mirror-like structures were observed on a large minority (30%) of the orbits. For the majority of these passes the signatures start close, or adjacent, to the magnetopause, despite a variety of upstream solar wind conditions, suggesting that in most cases the plasma depletion layer (PDL) was either narrow or absent. Without extensive plasma data the PDL cannot be observed directly. Using high-resolution magnetic field data, however, we have surveyed the occurrence of electromagnetic ion cyclotron (EMIC) waves in the magnetosheath, which have been used by previous authors as a proxy for PDL occurrence. Only a very small number (11) of the 130 documented crossings showed the presence of an ion cyclotron signature in the adjacent magnetosheath, supporting the hypothesis that the PDL is rare in this region. Two of these crossings had proton number density data available, although the wave signatures were exceptionally weak and short-lived. In these cases we find no clear evidence for a region of plasma depletion, suggesting that the relationship between a PDL and short bursts of EMIC wave occurrence may not be straightforward.

  10. Kinetic Alfvén turbulence below and above ion cyclotron frequency

    NASA Astrophysics Data System (ADS)

    Zhao, J. S.; Voitenko, Y. M.; Wu, D. J.; Yu, M. Y.

    2016-01-01

    Alfvénic turbulent cascade perpendicular and parallel to the background magnetic field is studied accounting for anisotropic dispersive effects and turbulent intermittency. The perpendicular dispersion and intermittency make the perpendicular-wave-number magnetic spectra steeper and speed up production of high ion cyclotron frequencies by the turbulent cascade. On the contrary, the parallel dispersion makes the spectra flatter and decelerate the frequency cascade above the ion cyclotron frequency. Competition of these factors results in spectral indices distributed in the interval [-2, -3], where -2 is the index of high-frequency space-filling turbulence and -3 is the index of low-frequency intermittent turbulence formed by tube-like fluctuations. Spectra of fully intermittent turbulence fill a narrower range of spectral indices [-7/3, -3], which almost coincides with the range of indexes measured in the solar wind. This suggests that the kinetic-scale turbulent spectra are mainly shaped by the dispersion and intermittency. A small mismatch with measured indexes of about 0.1 can be associated with damping effects not studied here.

  11. Limitations of electron cyclotron resonance ion source performances set by kinetic plasma instabilities

    SciTech Connect

    Tarvainen, O. Laulainen, J.; Komppula, J.; Kronholm, R.; Kalvas, T.; Koivisto, H.; Izotov, I.; Mansfeld, D.; Skalyga, V.

    2015-02-15

    Electron cyclotron resonance ion source (ECRIS) plasmas are prone to kinetic instabilities due to anisotropy of the electron energy distribution function stemming from the resonant nature of the electron heating process. Electron cyclotron plasma instabilities are related to non-linear interaction between plasma waves and energetic electrons resulting to strong microwave emission and a burst of energetic electrons escaping the plasma, and explain the periodic oscillations of the extracted beam currents observed in several laboratories. It is demonstrated with a minimum-B 14 GHz ECRIS operating on helium, oxygen, and argon plasmas that kinetic instabilities restrict the parameter space available for the optimization of high charge state ion currents. The most critical parameter in terms of plasma stability is the strength of the solenoid magnetic field. It is demonstrated that due to the instabilities the optimum B{sub min}-field in single frequency heating mode is often ≤0.8B{sub ECR}, which is the value suggested by the semiempirical scaling laws guiding the design of modern ECRISs. It is argued that the effect can be attributed not only to the absolute magnitude of the magnetic field but also to the variation of the average magnetic field gradient on the resonance surface.

  12. Generation of plasma rotation in a tokamak by ion-cyclotron absorption of fast Alfven waves

    SciTech Connect

    F.W. Perkins; R.B. White; P. Bonoli

    2000-06-13

    Control of rotation in tokamak plasmas provides a method for suppressing fine-scale turbulent transport by velocity shear and for stabilizing large-scale magnetohydrodynamic instabilities via a close-fitting conducting shell. The experimental discovery of rotation in a plasma heated by the fast-wave minority ion cyclotron process is important both as a potential control method for a fusion reactor and as a fundamental issue, because rotation arises even though this heating process introduces negligible angular momentum. This paper proposes and evaluates a mechanism which resolves this apparent conflict. First, it is assumed that angular momentum transport in a tokamak is governed by a diffusion equation with a no-slip boundary condition at the plasma surface and with a torque-density source that is a function of radius. When the torque density source consists of two separated regions of positive and negative torque density, a non-zero central rotation velocity results, even when the total angular momentum input vanishes. Secondly, the authors show that localized ion-cyclotron heating can generate regions of positive and negative torque density and consequently central plasma rotation.

  13. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL (invited)a)

    NASA Astrophysics Data System (ADS)

    Zhao, H. W.; Sun, L. T.; Zhang, X. Z.; Guo, X. H.; Cao, Y.; Lu, W.; Zhang, Z. M.; Yuan, P.; Song, M. T.; Zhao, H. Y.; Jin, T.; Shang, Y.; Zhan, W. L.; Wei, B. W.; Xie, D. Z.

    2008-02-01

    There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6T at injection, 2.2T at extraction, and a radial sextupole field of 2.0T at plasma chamber wall. During the commissioning phase at 18GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5kW by two 18GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810eμA of O7+, 505eμA of Xe20+, 306eμA of Xe27+, and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007.

  14. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

    PubMed

    Zhao, H W; Sun, L T; Zhang, X Z; Guo, X H; Cao, Y; Lu, W; Zhang, Z M; Yuan, P; Song, M T; Zhao, H Y; Jin, T; Shang, Y; Zhan, W L; Wei, B W; Xie, D Z

    2008-02-01

    There has been increasing demand to provide higher beam intensity and high enough beam energy for heavy ion accelerator and some other applications, which has driven electron cyclotron resonance (ECR) ion source to produce higher charge state ions with higher beam intensity. One of development trends for highly charged ECR ion source is to build new generation ECR sources by utilization of superconducting magnet technology. SECRAL (superconducting ECR ion source with advanced design in Lanzhou) was successfully built to produce intense beams of highly charged ion for Heavy Ion Research Facility in Lanzhou (HIRFL). The ion source has been optimized to be operated at 28 GHz for its maximum performance. The superconducting magnet confinement configuration of the ion source consists of three axial solenoid coils and six sextupole coils with a cold iron structure as field booster and clamping. An innovative design of SECRAL is that the three axial solenoid coils are located inside of the sextupole bore in order to reduce the interaction forces between the sextupole coils and the solenoid coils. For 28 GHz operation, the magnet assembly can produce peak mirror fields on axis of 3.6 T at injection, 2.2 T at extraction, and a radial sextupole field of 2.0 T at plasma chamber wall. During the commissioning phase at 18 GHz with a stainless steel chamber, tests with various gases and some metals have been conducted with microwave power less than 3.5 kW by two 18 GHz rf generators. It demonstrates the performance is very promising. Some record ion beam intensities have been produced, for instance, 810 e microA of O(7+), 505 e microA of Xe(20+), 306 e microA of Xe(27+), and so on. The effect of the magnetic field configuration on the ion source performance has been studied experimentally. SECRAL has been put into operation to provide highly charged ion beams for HIRFL facility since May 2007. PMID:18315105

  15. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    SciTech Connect

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Hojo, S.; Sakamoto, Y.; Sato, S.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Ueda, T.; Miyazaki, H.; Drentje, A. G.

    2008-11-03

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C{sup 4+} based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C{sup 4+} was obtained to be 618 e{mu}A under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  16. Development of Compact Electron Cyclotron Resonance Ion Source with Permanent Magnets for High-Energy Carbon-Ion Therapy

    NASA Astrophysics Data System (ADS)

    Muramatsu, M.; Kitagawa, A.; Iwata, Y.; Hojo, S.; Sakamoto, Y.; Sato, S.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Ueda, T.; Miyazaki, H.; Drentje, A. G.

    2008-11-01

    Heavy-ion cancer treatment is being carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) with 140 to 400 MeV/n carbon ions at National Institute of Radiological Sciences (NIRS) since 1994. At NIRS, more than 4,000 patients have been treated, and the clinical efficiency of carbon ion radiotherapy has been demonstrated for many diseases. A more compact accelerator facility for cancer therapy is now being constricted at the Gunma University. In order to reduce the size of the injector (consists of ion source, low-energy beam transport and post-accelerator Linac include these power supply and cooling system), an ion source requires production of highly charged carbon ions, lower electric power for easy installation of the source on a high-voltage platform, long lifetime and easy operation. A compact Electron Cyclotron Resonance Ion Source (ECRIS) with all permanent magnets is one of the best types for this purpose. An ECRIS has advantage for production of highly charged ions. A permanent magnet is suitable for reduce the electric power and cooling system. For this, a 10 GHz compact ECRIS with all permanent magnets (Kei2-source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59 T at the extraction side and 0.87 T at the gas-injection side, while the minimum B strength is 0.25 T. These parameters have been optimized for the production of C4+ based on experience at the 10 GHz NIRS-ECR ion source. The Kei2-source has a diameter of 320 mm and a length of 295 mm. The beam intensity of C4+ was obtained to be 618 eμA under an extraction voltage of 30 kV. Outline of the heavy ion therapy and development of the compact ion source for new facility are described in this paper.

  17. The electron cyclotron resonance ion source with arc-shaped coils concept (invited).

    PubMed

    Koivisto, H; Suominen, P; Tarvainen, O; Spädtke, P

    2012-02-01

    The main limitation to further improve the performance of ECR ion sources is set by the magnet technology related to the multipole magnet field used for the closed minimum-B structure. The JYFL ion source group has sought different approaches to improve the strength of the minimum-B structure required for the production of highly charged ion beams. It was found out that such a configuration can be realized with arc shaped coils. The first prototype, electron cyclotron resonance ion source with arc-shaped coils (ARC-ECRIS), was constructed and tested at JYFL in 2006. It was confirmed that such an ion source can be used for the production of highly charged ion beams. Regardless of several cost-driven compromises such as extraction mirror ratio of 1.05-1.2, microwave frequency of 6.4 GHz, and beam line with limited capacity, Ar(4+) beam intensity of up to 2 μA was measured. Subsequent design study has shown that the ARC-ECRIS operating at the microwave frequency above 40 GHz could be constructed. This specific design would be based on NbTi-wires and it fulfills the experimental magnetic field scaling laws. In this article, the ARC-ECRIS concept and its potential applications will be described. PMID:22380159

  18. Langmuir probe diagnostics of plasma in high current electron cyclotron resonance proton ion source

    SciTech Connect

    Roychowdhury, P.; Kewlani, H.; Mishra, L.; Mittal, K. C.; Patil, D. S.

    2013-07-15

    A high current Electron Cyclotron Resonance (ECR) proton ion source has been developed for low energy high intensity proton accelerator at Bhabha Atomic Research Centre. Langmuir probe diagnostics of the plasma generated in this proton ion source is performed using Langmuir probe. The diagnostics of plasma in the ion source is important as it determines beam parameters of the ion source, i.e., beam current, emittance, and available species. The plasma parameter measurement in the ion source is performed in continuously working and pulsed mode using hydrogen as plasma generation gas. The measurement is performed in the ECR zone for operating pressure and microwave power range of 10{sup −4}–10{sup −3} mbar and 400–1000 W. An automated Langmuir probe diagnostics unit with data acquisition system is developed to measure these parameters. The diagnostics studies indicate that the plasma density and plasma electron temperature measured are in the range 5.6 × 10{sup 10} cm{sup −3} to 3.8 × 10{sup 11} cm{sup −3} and 4–14 eV, respectively. Using this plasma, ion beam current of tens of mA is extracted. The variations of plasma parameters with microwave power, gas pressure, and radial location of the probe have been studied.

  19. First results from the new RIKEN superconducting electron cyclotron resonance ion source (invited).

    PubMed

    Nakagawa, T; Higurashi, Y; Ohnishi, J; Aihara, T; Tamura, M; Uchiyama, A; Okuno, H; Kusaka, K; Kidera, M; Ikezawa, E; Fujimaki, M; Sato, Y; Watanabe, Y; Komiyama, M; Kase, M; Goto, A; Kamigaito, O; Yano, Y

    2010-02-01

    The next generation heavy ion accelerator facility, such as the RIKEN radio isotope (RI) beam factory, requires an intense beam of high charged heavy ions. In the past decade, performance of the electron cyclotron resonance (ECR) ion sources has been dramatically improved with increasing the magnetic field and rf frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key parameters (magnetic field configuration, gas pressure, etc.) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and modern superconducting (SC) technology, we successfully constructed the new 28 GHz SC-ECRIS, which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. Using it, we investigated the effect of ECR zone size, magnetic field configuration, and biased disk on the beam intensity of the highly charged heavy ions with 18 GHz microwaves. In this article, we present the structure of the ion source and first experimental results with 18 GHz microwave in detail. PMID:20192341

  20. Potential applications of a new microwave ECR (electron cyclotron resonance) multicusp plasma ion source

    SciTech Connect

    Tsai, C.C.

    1990-01-01

    A new microwave electron cyclotron resonance (ECR) multicusp plasma ion source using two ECR plasma production regions and multicusp plasma confinement has been developed at Oak Ridge National Laboratory. This source has been operated to produce uniform and dense plasmas over large areas of 300 to 400 cm{sup 2}. The plasma source has been operated with continuous argon gas feed and pulsed microwave power. The discharge initiation phenomena and plasma properties have been investigated and studied as functions of discharge parameters. Together with the discharge characteristics observed, a hypothetical discharge mechanism for this plasma source is reported and discussed. Potential applications, including plasma and ion-beam processing for manufacturing advanced microelectronics and for space electric propulsion, are discussed. 7 refs., 6 figs.

  1. Transverse distribution of beam current oscillations of a 14 GHz electron cyclotron resonance ion source.

    PubMed

    Tarvainen, O; Toivanen, V; Komppula, J; Kalvas, T; Koivisto, H

    2014-02-01

    The temporal stability of oxygen ion beams has been studied with the 14 GHz A-ECR at JYFL (University of Jyvaskyla, Department of Physics). A sector Faraday cup was employed to measure the distribution of the beam current oscillations across the beam profile. The spatial and temporal characteristics of two different oscillation "modes" often observed with the JYFL 14 GHz ECRIS are discussed. It was observed that the low frequency oscillations below 200 Hz are distributed almost uniformly. In the high frequency oscillation "mode," with frequencies >300 Hz at the core of the beam, carrying most of the current, oscillates with smaller amplitude than the peripheral parts of the beam. The results help to explain differences observed between the two oscillation modes in terms of the transport efficiency through the JYFL K-130 cyclotron. The dependence of the oscillation pattern on ion source parameters is a strong indication that the mechanisms driving the fluctuations are plasma effects. PMID:24593488

  2. Performance of an ion-cyclotron-wave plasma apparatus operated in the radiofrequency sustained mode

    NASA Technical Reports Server (NTRS)

    Swett, C. C.; Woollett, R. R.

    1973-01-01

    An experimental study has been made of an ion-cyclotron-wave apparatus operated in the RF-sustained mode, that is, a mode in which the Stix RF coil both propagates the waves and maintains the plasma. Problems associated with this method of operation are presented. Some factors that are important to the coupling of RF power are noted. In general, the wave propagation and wave damping data agree with theory. Some irregularities in wave fields are observed. Maximum ion temperature is 870 eV at a density of five times 10 to the 12th power cu cm and RF power of 90 kW. Coupling efficiency is 70 percent.

  3. Two-chamber configuration of Bio-Nano electron cyclotron resonance ion source for fullerene modification

    NASA Astrophysics Data System (ADS)

    Uchida, T.; Rácz, R.; Muramatsu, M.; Kato, Y.; Kitagawa, A.; Biri, S.; Yoshida, Y.

    2016-02-01

    We report on the modification of fullerenes with iron and chlorine using two individually controllable plasmas in the Bio-Nano electron cyclotron resonance ion source (ECRIS). One of the plasmas is composed of fullerene and the other one is composed of iron and chlorine. The online ion beam analysis allows one to investigate the rate of the vapor-phase collisional modification process in the ECRIS, while the offline analyses (e.g., liquid chromatography-mass spectrometry) of the materials deposited on the plasma chamber can give information on the surface-type process. Both analytical methods show the presence of modified fullerenes such as fullerene-chlorine, fullerene-iron, and fullerene-chlorine-iron.

  4. Nonlocal effects on the convective properties of the electrostatic current-driven ion-cyclotron instability

    NASA Technical Reports Server (NTRS)

    Ganguli, G.; Bakshi, P.; Palmadesso, P.

    1984-01-01

    The convective behavior of the current-driven ion-cyclotron instability (CDICI) in the presence of nonlocal magnetic-shear and current-channel-width effects is investigated theoretically using the analytical approach of Bakshi et al. (1983). The results are presented in graphs and discussed. Three different CDICI regimes defined by the ratio of the channel width to the shear length are obtained: a purely nonlocal regime with reduced temporal growth rate and group velocity in the z direction going to zero (ratios greater than about 0.1); a regime corresponding to the results of local theory (ratios less than 0.01); and a regime characterized by decreasing temporal growth rate and by z and y group velocities which become negative when the channel width becomes less than the mean ion Larmor radius (ratios 0.001 or less).

  5. Finite-width currents, magnetic shear, and the current-driven ion-cyclotron instability

    NASA Technical Reports Server (NTRS)

    Bakshi, P.; Ganguli, G.; Palmadesso, P.

    1983-01-01

    Our earlier results that non-local effects due to even a small magnetic shear produce a significant reduction of the growth rate of the ion cyclotron instability driven by a uniform current are now generalized to finite width currents. Externally prescribed as well as self-consistent shears are considered. If the current width Lc exceeds the shear length Ls, the previous results are recovered. Shear becomes less effective with reduction of Lc, and for typical parameters, the growth rate attains its (shearless) local value for Lc/Ls approximately less than 10 to the minus 2. Non-local effects of the finite current width itself come into play if Lc is further reduced to a few ion Larmor radii and can quench the instability. Previously announced in STAR as N83-28996

  6. Ion heating in the field-reversed configuration (FRC) by rotating magnetic fields (RMF) near cyclotron resonance

    SciTech Connect

    Samuel A. Cohen; Alan H. Glasser

    2000-07-20

    The trajectories of ions confined in a Solovev FRC equilibrium magnetic geometry and heated with a small-amplitude, odd-parity rotating magnetic field, have been studied with a Hamiltonian computer code. When the RMF frequency is in the ion-cyclotron range, explosive heating occurs. Higher-energy ions are found to have betatron-type orbits, preferentially localized near the FRC midplane. These results are relevant to a compact magnetic-fusion-reactor design.

  7. New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

    SciTech Connect

    Zhao, H. W.; Sun, L. T.; Zhang, X. Z.; Guo, X. H.; Zhao, H. Y.; Feng, Y. C.; Li, J. Y.; Ma, H. Y.; Ma, B. H.; Wang, H.; Li, X. X.; Xie, D. Z.; Lu, W.; Cao, Y.; Shang, Y.

    2010-02-15

    Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e {mu}A of {sup 129}Xe{sup 43+}, 22 e {mu}A of {sup 209}Bi{sup 41+}, and 1.5 e {mu}A of {sup 209}Bi{sup 50+}. To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e {mu}A of {sup 129}Xe{sup 27+} and 152 e {mu}A of {sup 129}Xe{sup 30+}, although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and {sup 129}Xe{sup 27+}, {sup 78}Kr{sup 19+}, {sup 209}Bi{sup 31+}, and {sup 58}Ni{sup 19+} beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of

  8. New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited).

    PubMed

    Zhao, H W; Sun, L T; Lu, W; Zhang, X Z; Guo, X H; Cao, Y; Zhao, H Y; Feng, Y C; Li, J Y; Ma, H Y; Shang, Y; Ma, B H; Wang, H; Li, X X; Xie, D Z

    2010-02-01

    Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e microA of (129)Xe(43+), 22 e microA of (209)Bi(41+), and 1.5 e microA of (209)Bi(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e microA of (129)Xe(27+) and 152 e microA of (129)Xe(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and (129)Xe(27+), (78)Kr(19+), (209)Bi(31+), and (58)Ni(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production

  9. On the Generation and Dissipation of Ion Cyclotron Waves in the Extended Solar Corona

    NASA Astrophysics Data System (ADS)

    Cranmer, S. R.

    1999-12-01

    The dissipation of high frequency (10 to 10,000 Hz) ion cyclotron resonant Alfven waves has been proposed as a leading candidate for the heating of the extended solar corona and the acceleration of the high speed solar wind. The competition between various wave generation mechanisms and resonant wave damping is examined in detail, and a database of more than 2000 low-abundance ion species is taken into account for completeness. Also, the Sobolev approximation from the theory of hot star winds is applied to the gyroresonant wave-particle interaction in the solar wind, and the surprisingly effective damping ability of ``minor'' ions is explained in simple terms. High frequency waves (propagating parallel to open magnetic field lines) that originate at the base of the corona are damped significantly when they resonate with ions having charge-to-mass ratios of about 0.1. Thus, if the waves came solely from the coronal base, there would be negligible wave power available to resonate with higher charge-to-mass ratio ions at larger heights. This result confirms preliminary suggestions from earlier work that the waves that heat and accelerate the high speed solar wind must be generated throughout the extended corona. This work is supported by the National Aeronautics and Space Administration under grant NAG5-7822 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the ESA PRODEX program (Swiss contribution).

  10. Ion heating and acceleration by magnetosonic waves via cyclotron subharmonic resonance

    SciTech Connect

    Terasawa, Toshio ); Nambu, Mitsuhiro )

    1989-05-01

    The authors investigate a subharmonic-resonant interaction between ions and magnetohydrodynamic waves propagating perpendicular to the background magnetic field, B{sub 0}. This interaction occurs at frequencies which are subharmonics of the cyclotron frequency of ions ({Omega}{sub i}/n, where n is an integer, 2,3,4,..). They have found that this interaction becomes quite effective if the wave magnetic field {delta}B exceeds {approximately}10% of B{sub 0}. Further, when {delta}B exceeds {approximately}50% of B{sub 0}, ions have stochastic orbits in the wave and are accelerated with quite high efficiency. This subharmonic resonant interaction can play quite significant roles in the ion heating/acceleration processes in space plasmas, where large amplitude waves ({delta}B/B{sub 0}{approx gt}0.1) are not unusual. Possible observational features of the subharmonic resonance which they suggest are: (1) absorption lines in the broad background spectrum of compressible geomagnetic pulsations, and (2) enhancement of energetic ion fluxes relating to the large fluctuation of magnetic field magnitude.

  11. A simulation of X-ray shielding for a superconducting electron cyclotron resonance ion source

    SciTech Connect

    Park, Jin Yong; Won, Mi-Sook; Lee, Byoung-Seob; Yoon, Jang-Hee; Choi, Seyong; Ok, Jung-Woo; Choi, Jeong-Sik; Kim, Byoung-Chul

    2014-02-15

    It is generally assumed that large amounts of x-rays are emitted from the ion source of an Electron Cyclotron Resonance (ECR) instrument. The total amount of x-rays should be strictly limited to avoid the extra heat load to the cryostat of the superconducting ECR ion source, since they are partly absorbed by the cold mass into the cryostat. A simulation of x-ray shielding was carried out to determine the effective thickness of the x-ray shield needed via the use of Geant4. X-ray spectra of the 10 GHz Nanogan ECR ion source were measured as a function of the thickness variation in the x-ray shield. The experimental results were compared with Geant4 results to verify the effectiveness of the x-ray shield. Based on the validity in the case of the 10 GHz ECR ion source, the x-ray shielding results are presented by assuming the spectral temperature of the 28 GHz ECR ion source.

  12. Time evolution of endpoint energy of Bremsstrahlung spectra and ion production from an electron cyclotron resonance ion source

    SciTech Connect

    Tarvainen, Ollie; Ropponen, Tommi; Jones, Peter; Kalvas, Taneli

    2008-01-01

    Electron cyclotron resonance ion sources (ECRIS) are used to produce high charge state heavy ion beams for the use of nuclear and materials science, for instance. The most powerful ECR ion sources today are superconducting. One of the problems with superconducting ECR ion sources is the use of high radio frequency (RF) power which results in bremsstrahlung radiation adding an extra heat load to the cryostat. In order to understand the electron heating process and timescales in the ECR plasma, time evolution measurement of ECR bremsstrahlung was carried out. In the measurements JYFL 14 GHz ECRIS was operated in a pulsed mode and bremsstrahlung data from several hundred RF pulses was recorded. Time evolution of ion production was also studied and compared to one of the electron heating theories. To analyze the measurement data at C++ program was developed. Endpoint energies of the bremsstrahlung spectra as a function of axial magnetic field strength, pressure and RF power are presented and ion production timescales obtained from the measurements are compared to bremsstrahlung emission timescales and one of the stochastic heating theories.

  13. Chirped dissipative ion-cyclotron solitons in the Earth's low-altitude ionospheric plasma with two ion species

    SciTech Connect

    Kovaleva, I. Kh.

    2013-03-15

    Conditions for the excitation of small-scale nonlinear ion-cyclotron gradient-drift dissipative structures in cold ionospheric plasma are considered. The solution for the wave electric field in this structure in the form of a chirped soliton satisfying the equation of the Ginzburg-Landau type is derived in the electrostatic approach. The dissipative structure as a whole represents the chirped soliton accompanied by the comoving quasineutral plasma hump. The possibility of the excitation of two modes of this type (the high- and low-frequency ones) in plasma containing light and heavy ion impurities is considered. The role of electromagnetic corrections and the possible contribution introduced by these structures to the transport processes in the ionosphere are discussed.

  14. Self-Consistent Model of Magnetospheric Ring Current and Propagating Electromagnetic Ion Cyclotron Waves: Waves in Multi-Ion Magnetosphere

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.; Gallagher, D. L.; Kozyra, J. U.

    2006-01-01

    The further development of a self-consistent theoretical model of interacting ring current ions and electromagnetic ion cyclotron waves (Khazanov et al., 2003) is presented In order to adequately take into account wave propagation and refraction in a multi-ion magnetosphere, we explicitly include the ray tracing equations in our previous self-consistent model and use the general form of the wave kinetic equation. This is a major new feature of the present model and, to the best of our knowledge, the ray tracing equations for the first time are explicitly employed on a global magnetospheric scale in order to self-consistently simulate the spatial, temporal, and spectral evolution of the ring current and of electromagnetic ion cyclotron waves To demonstrate the effects of EMIC wave propagation and refraction on the wave energy distribution and evolution, we simulate the May 1998 storm. The main findings of our simulation can be summarized as follows. First, owing to the density gradient at the plasmapause, the net wave refraction is suppressed, and He+-mode grows preferably at the plasmapause. This result is in total agreement with previous ray tracing studies and is very clearly found in presented B field spectrograms. Second, comparison of global wave distributions with the results from another ring current model (Kozyra et al., 1997) reveals that this new model provides more intense and more highly plasmapause-organized wave distributions during the May 1998 storm period Finally, it is found that He(+)-mode energy distributions are not Gaussian distributions and most important that wave energy can occupy not only the region of generation, i.e., the region of small wave normal angles, but all wave normal angles, including those to near 90 . The latter is extremely crucial for energy transfer to thermal plasmaspheric electrons by resonant Landau damping and subsequent downward heat transport and excitation of stable auroral red arcs.

  15. Self-Consistent Model of Magnetospheric Ring Current and Propagating Electromagnetic Ion Cyclotron Waves. 1; Waves in Multi Ion Magnetosphere

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gumayunov, K. V.; Gallagher, D. L.; Kozyra, J. U.

    2006-01-01

    The further development of a self-consistent theoretical model of interacting ring current ions and electromagnetic ion cyclotron waves [Khazanov et al., 2003] is presented. In order to adequately take into account the wave propagation and refraction in a multi-ion plasmasphere, we explicitly include the ray tracing equations in our previous self-consistent model and use the general form of the wave kinetic equation. This is a major new feature of the present model and, to the best of our knowledge, the ray tracing equations for the first time are explicitly employed on a global magnetospheric scale in order to self-consistently simulate spatial, temporal, and spectral evolutions of the ring current and electromagnetic ion cyclotron waves. To demonstrate the effects of EMIC wave propagation and refraction on the EMIC wave energy distributions and evolution we simulate the May 1998 storm. The main findings of our simulation can be summarized as follows. First, due to the density gradient at the plasmapause, the net wave refraction is suppressed, and He(+)-mode grows preferably at plasmapause. This result is in a total agreement with the previous ray tracing studies, and very clear observed in presented B-field spectrograms. Second, comparison the global wave distributions with the results from other ring current model [Kozyra et al., 1997] reveals that our model provides more intense and higher plasmapause organized distributions during the May, 1998 storm period. Finally, the found He(+)-mode energy distributions are not Gaussian distributions, and most important that wave energy can occupy not only the region of generation, i. e. the region of small wave normal angles, but the entire wave normal angle region and even only the region near 90 degrees. The latter is extremely crucial for energy transfer to thermal plasmaspheric electrons by resonant Landau damping, and subsequent downward heat transport and excitation of stable auroral red arcs.

  16. Status report of the 28 GHz superconducting electron cyclotron resonance ion source VENUS (invited)

    SciTech Connect

    Leitner, D.; Lyneis, C.M.; Loew, T.; Todd, D.S.; Virostek, S.; Tarvainen, O.

    2006-03-15

    The superconducting versatile electron cyclotron resonance (ECR) ion source for nuclear science (VENUS) is a next generation superconducting ECR ion source designed to produce high-current, high-charge-state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the rare isotope accelerator (RIA) front end, where the goal is to produce intense beams of medium-charge-state ions. Example beams for the RIA accelerator are 15 p {mu}A of Kr{sup 17+}(260 e {mu}A), 12 p {mu}A of Xe{sup 20+} (240 e {mu}A of Xe{sup 20+}), and 8 p {mu}A of U{sup 28+}(230 e {mu}A). To achieve these high currents, VENUS has been optimized for operation at 28 GHz, reaching maximal confinement fields of 4 and 3 T axially and over 2.2 T on the plasma chamber wall radially. After a commissioning phase at 18 GHz, the source started the 28 GHz operation in the summer of 2004. During that ongoing 28 GHz commissioning process, record ion-beam intensities have been extracted. For instance, measured extracted currents for the low to medium charge states were 270 e {mu}A of Xe{sup 27+} and 245 e {mu}A of Bi{sup 29+}, while for the higher charge states 15 e {mu}A of Xe{sup 34+}, 15 e {mu}A of Bi{sup 41+}, and 0.5 e {mu}A of Bi{sup 50+} could be produced. Results from the ongoing 28 GHz commissioning as well as results using double-frequency heating with 18 and 28 GHz for oxygen and xenon are presented. The effect of the minimum B field on the ion source performance has been systematically measured for 18 and 28 GHz. In both cases the performance peaked at a minimum B field of about 80% of the resonance field. In addition, a strong dependence of the x-ray flux and energy on the minimum B field value was found.

  17. Status report of the 28 GHz superconducting electron cyclotron resonance ion source VENUS (invited)

    NASA Astrophysics Data System (ADS)

    Leitner, D.; Lyneis, C. M.; Loew, T.; Todd, D. S.; Virostek, S.; Tarvainen, O.

    2006-03-01

    The superconducting versatile electron cyclotron resonance (ECR) ion source for nuclear science (VENUS) is a next generation superconducting ECR ion source designed to produce high-current, high-charge-state ions for the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. VENUS also serves as the prototype ion source for the rare isotope accelerator (RIA) front end, where the goal is to produce intense beams of medium-charge-state ions. Example beams for the RIA accelerator are 15 p μA of Kr17+(260 e μA), 12 p μA of Xe20+ (240 e μA of Xe20+), and 8 p μA of U28+(230 e μA). To achieve these high currents, VENUS has been optimized for operation at 28 GHz, reaching maximal confinement fields of 4 and 3 T axially and over 2.2 T on the plasma chamber wall radially. After a commissioning phase at 18 GHz, the source started the 28 GHz operation in the summer of 2004. During that ongoing 28 GHz commissioning process, record ion-beam intensities have been extracted. For instance, measured extracted currents for the low to medium charge states were 270 e μA of Xe27+ and 245 e μA of Bi29+, while for the higher charge states 15 e μA of Xe34+, 15 e μA of Bi41+, and 0.5 e μA of Bi50+ could be produced. Results from the ongoing 28 GHz commissioning as well as results using double-frequency heating with 18 and 28 GHz for oxygen and xenon are presented. The effect of the minimum B field on the ion source performance has been systematically measured for 18 and 28 GHz. In both cases the performance peaked at a minimum B field of about 80% of the resonance field. In addition, a strong dependence of the x-ray flux and energy on the minimum B field value was found.

  18. Electrically compensated Fourier transform ion cyclotron resonance cell for complex mixture mass analysis.

    PubMed

    Kaiser, Nathan K; Savory, Joshua J; McKenna, Amy M; Quinn, John P; Hendrickson, Christopher L; Marshall, Alan G

    2011-09-01

    Complex natural organic mixtures such as petroleum require ultrahigh mass spectral resolution to separate and identify thousands of elemental compositions. Here, we incorporate a custom-built, voltage-compensated ICR cell for Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), based on a prior design by Tolmachev to produce optimal mass resolution. The compensated ICR cell installed in a custom-built 9.4 T FTICR mass spectrometer consists of seven cylindrical segments with axial proportions designed to generate a dc trapping potential that approaches an ideal three-dimensional axial quadrupolar potential. However, the empirically optimized compensation voltages do not correspond to the most quadrupolar trapping field. The compensation electrodes minimize variation in the reduced cyclotron frequency by balancing imperfections in the magnetic and electric field. The optimized voltages applied to compensation electrodes preserve ion cloud coherence for longer transient duration by approximately a factor of 2, enabling separation and identification of isobaric species (compounds with the same nominal mass but different exact mass) common in petroleum, such as C(3) vs SH(4) (separated by 3.4 mDa) and SH(3)(13)C vs (12)C(4) (separated by 1.1 mDa). The improved performance of the ICR cell provides more symmetric peak shape and better mass measurement accuracy. A positive ion atmospheric pressure photoionization (APPI) petroleum spectrum yields more than 26,000 assigned peaks, Fourier-limited resolving power of 800,000 at m/z 500 (6.6 s transient duration), and 124 part per billion root mean square (rms) error. The tunability of the compensation electrodes is critical for optimal performance. PMID:21838231

  19. Development of steady-state operation using ion cyclotron heating in the Large Helical Device

    SciTech Connect

    Kasahara, H.; Seki, T.; Saito, K.; Seki, R.; Kumazawa, R.; Yoshimura, Y.; Kubo, S.; Shimozuma, T.; Igami, H.; Takahashi, H.; Tokitani, M.; Ashikawa, N.; Shoji, M.; Kamio, S.; Tsuchiya, H.; Yoshimura, S.; Tamura, N.; Suzuki, C.; Yamada, H.; Mutoh, T.; and others

    2014-06-15

    Using a handshake shape (HAS) antenna phasing dipole for ion cyclotron heating (ICH), the heating efficiency was higher than that using a previous poloidal array antenna in the Large Helical Device. In order to sustain the dipole operation, real-time feedback for impedance matching and maintaining the same phase and power was adopted during long-pulse discharge. The HAS antenna was designed to reduce parasitic losses associated with energetic particle and radio-frequency (RF) sheath effects by field-aligned current concentration on the midplane. Local hot spots and the inhomogeneity of the diverter heat profile in the toroidal direction were reduced. The long-pulse discharge with an electron density (n{sub e0}) of 1 × 10{sup 19} m{sup −3}, center electron temperature (T{sub e0}) of 2.5 keV, a plasma duration time (t{sub d}) of 19 min, and RF heating power (P{sub RF}) of 1 MW was achieved by ICH and electron cyclotron heating.

  20. Spectral features of lightning-induced ion cyclotron waves at low latitudes: DEMETER observations and simulation

    NASA Astrophysics Data System (ADS)

    Shklyar, D. R.; Storey, L. R. O.; Chum, J.; JiříčEk, F.; NěMec, F.; Parrot, M.; Santolik, O.; Titova, E. E.

    2012-12-01

    We use a comprehensive analysis of 6-component ELF wave data from the DEMETER satellite to study proton whistlers, placing emphasis on low-latitude events originating from lightning strokes in the hemisphere opposite to the hemisphere of observation. In this case, the formation of proton whistlers does not involve mode conversion caused by a strong mode coupling at a crossover frequency, although a polarization reversal remains an important element in formation of the phenomenon. DEMETER measurements of the six electromagnetic field components in the frequency band below 1000 Hz make it possible to determine not only the dynamic spectrum, but also the wave polarization, the wave normal angle, and the normalized parallel component of the Poynting vector. This permits us to address fine features of proton whistlers, in particular, we show that the deviation of the upper cutoff frequency from the equatorial cyclotron frequency is related to the Doppler shift. Experimental study of proton whistlers is supplemented by an investigation of ion cyclotron wave propagation in a multicomponent magnetoplasma and by numerical modeling of spectrograms, both in the frame of geometrical optics.

  1. Neoclassical transport of energetic minority tail ions generated by ion-cyclotron resonance heating in tokamak geometry

    SciTech Connect

    Chang, C.S. . Courant Inst. of Mathematical Sciences); Hammett, G.W.; Goldston, R.J. . Plasma Physics Lab.)

    1990-01-01

    Neoclassical transport of energetic minority tail ions, which are generated by high powered electromagnetic waves of the Ion Cyclotron Range of Frequencies (ICRF) at the fundamental harmonic resonance, is studied analytically in tokamak geometry. The effect of Coulomb collisions on the tail ion transport is investigated in the present work. The total tail ion transport will be the sum of the present collision-driven transport and the wave-driven transport, which is due to the ICRF-wave scattering of the tail particles as reported in the literature. The transport coefficients have been calculated kinetically, and it is found that the large tail ion viscosity, driven by the localized ICRF-heating and Coulomb slowing-down collisions, induces purely convective particle transport of the tail species, while the energy transport is both convective and diffusive. The rate of radial particle transport is shown to be usually small, but the rate of radial energy transport is larger and may not be negligible compared to the Coulomb slowing-down rate. 18 refs., 2 figs.

  2. An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources.

    PubMed

    Weichsel, T; Hartung, U; Kopte, T; Zschornack, G; Kreller, M; Silze, A

    2014-05-01

    An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10(10) cm(-3) to 1 × 10(11) cm(-3), when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10(18) atoms/s for aluminum, which meets the demand for the production of a milliampere Al(+) ion beam. PMID:24880358

  3. Project of electro-cyclotron resonance ion source test-bench for material investigation.

    PubMed

    Kulevoy, T V; Chalykh, B B; Kuibeda, R P; Kropachev, G N; Ziiatdinova, A V

    2014-02-01

    Development of new materials for future energy facilities with higher operating efficiency is a challenging and crucial task. However, full-scale testing of radiation hardness for reactor materials is quite sophisticated and difficult as it requires long session of reactor irradiation; moreover, induced radioactivity considerably complicates further investigation. Ion beam irradiation does not have such a drawback; on the contrary, it has certain advantages. One of them is high speed of defect formation. Therefore, it provides a useful tool for modeling of different radiation damages. Improved understanding of material behavior under high dose irradiation will probably allow to simulate reactor irradiation close to real conditions and to make an adequate estimation of material radiation hardness. Since 2008 in Institute for Theoretical and Experimental Physics, the ion beam irradiation experiments are under development at the heavy ion radio frequency quadrupole linac and very important results are obtained already [T. V. Kulevoy et al., in Proceedings of the International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators, IAEA Vienna, Austria, 2009, http://www.pub.iaea.org/MTCD/publications/PDF/P1433_CD/darasets/papers/ap_p5_07.pdf]. Nevertheless, the new test bench based on electro-cyclotron resonance ion source and high voltage platform is developed. The project of the test bench is presented and discussed. PMID:24593489

  4. Project of electro-cyclotron resonance ion source test-bench for material investigation

    NASA Astrophysics Data System (ADS)

    Kulevoy, T. V.; Chalykh, B. B.; Kuibeda, R. P.; Kropachev, G. N.; Ziiatdinova, A. V.

    2014-02-01

    Development of new materials for future energy facilities with higher operating efficiency is a challenging and crucial task. However, full-scale testing of radiation hardness for reactor materials is quite sophisticated and difficult as it requires long session of reactor irradiation; moreover, induced radioactivity considerably complicates further investigation. Ion beam irradiation does not have such a drawback; on the contrary, it has certain advantages. One of them is high speed of defect formation. Therefore, it provides a useful tool for modeling of different radiation damages. Improved understanding of material behavior under high dose irradiation will probably allow to simulate reactor irradiation close to real conditions and to make an adequate estimation of material radiation hardness. Since 2008 in Institute for Theoretical and Experimental Physics, the ion beam irradiation experiments are under development at the heavy ion radio frequency quadrupole linac and very important results are obtained already [T. V. Kulevoy et al., in Proceedings of the International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators, IAEA Vienna, Austria, 2009, http://www.pub.iaea.org/MTCD/publications/PDF/P1433_CD/darasets/papers/ap_p5_07.pdf]. Nevertheless, the new test bench based on electro-cyclotron resonance ion source and high voltage platform is developed. The project of the test bench is presented and discussed.

  5. An inverted cylindrical sputter magnetron as metal vapor supply for electron cyclotron resonance ion sources

    SciTech Connect

    Weichsel, T. Hartung, U.; Kopte, T.; Zschornack, G.; Kreller, M.; Silze, A.

    2014-05-15

    An inverted cylindrical sputter magnetron device has been developed. The magnetron is acting as a metal vapor supply for an electron cyclotron resonance (ECR) ion source. FEM simulation of magnetic flux density was used to ensure that there is no critical interaction between both magnetic fields of magnetron and ECR ion source. Spatially resolved double Langmuir probe and optical emission spectroscopy measurements show an increase in electron density by one order of magnitude from 1 × 10{sup 10} cm{sup −3} to 1 × 10{sup 11} cm{sup −3}, when the magnetron plasma is exposed to the magnetic mirror field of the ECR ion source. Electron density enhancement is also indicated by magnetron plasma emission photography with a CCD camera. Furthermore, photographs visualize the formation of a localized loss-cone - area, when the magnetron is operated at magnetic mirror field conditions. The inverted cylindrical magnetron supplies a metal atom load rate of R > 1 × 10{sup 18} atoms/s for aluminum, which meets the demand for the production of a milliampere Al{sup +} ion beam.

  6. The Nonlinear Coupling of Electromagnetic Ion Cyclotron and Lower Hybrid Waves in the Ring Current Region

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.

    2004-01-01

    The excitation of lower hybrid waves (LHWs) is a widely discussed mechanism of interaction between plasma species in space, and is one of the unresolved questions of magnetospheric multi-ion plasmas. In this paper we present the morphology, dynamics, and level of LHW activity generated by electromagnetic ion cyclotron (EMIC) waves during the May 2-7, 1998 storm period on the global scale. The LHWs were calculated based on a newly developed self-consistent model (Khazanov et. al., 2002, 2003) that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes the evolution of EMIC waves. It is found that the LHWs are excited by helium ions due to their mass dependent drift in the electric field of EMIC waves. The level of LHW activity is calculated assuming that the induced scattering process is the main saturation mechanism for these waves. The calculated LHWs electric fields are consistent with the observational data.

  7. Characterization of oligodeoxynucleotides by electron detachment dissociation fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Yang, Jiong; Mo, Jingjie; Adamson, Julie T; Håkansson, Kristina

    2005-03-15

    Electron detachment dissociation (EDD), recently introduced by Zubarev and co-workers for the dissociation of multiply charged biomolecular anions via a radical ion intermediate, has been shown to be analogous to electron capture dissociation (ECD) in several respects, including more random peptide fragmentation and retention of labile posttranslational modifications. We have previously demonstrated unique fragmentation behavior in ECD compared to vibrational excitation for oligodeoxynucleotide cations. However, that approach is limited by the poor sensitivity for oligonucleotide ionization in positive ion mode. Here, we show implementation of EDD on a commercial Fourier transform ion cyclotron resonance mass spectrometer utilizing two different configurations: a heated filament electron source and an indirectly heated hollow dispenser cathode electron source. The dispenser cathode configuration provides higher EDD efficiency and additional fragmentation channels for hexamer oligodeoxynucleotides. As in ECD, even-electron d/w ion series dominate the spectra, but we also detect numerous a/z (both even-electron and radical species), (a/z - B), c/x, (c/x - B), and (d/w - B) ions with minimal nucleobase loss from the precursor ions. In contrast to previous high-energy collision-activated dissociation (CAD) and ion trap CAD of radical oligonucleotide anions, we only observe minimum sugar cross-ring cleavage, possibly due to the short time scale of EDD, which limits secondary fragmentation. Thus, EDD provides fragmentation similar to ECD for oligodeoxynucleotides but at enhanced sensitivity. Finally, we show that noncovalent bonding in a DNA duplex can be preserved following EDD, illustrating another analogy with ECD. We believe the latter finding implies EDD has promise for characterization of nucleic acid structure and folding. PMID:15762599

  8. ION HEATING IN INHOMOGENEOUS EXPANDING SOLAR WIND PLASMA: THE ROLE OF PARALLEL AND OBLIQUE ION-CYCLOTRON WAVES

    SciTech Connect

    Ozak, N.; Ofman, L.; Viñas, A.-F.

    2015-01-20

    Remote sensing observations of coronal holes show that heavy ions are hotter than protons and their temperature is anisotropic. In-situ observations of fast solar wind streams provide direct evidence for turbulent Alfvén wave spectrum, left-hand polarized ion-cyclotron waves, and He{sup ++} - proton drift in the solar wind plasma, which can produce temperature anisotropies by resonant absorption and perpendicular heating of the ions. Furthermore, the solar wind is expected to be inhomogeneous on decreasing scales approaching the Sun. We study the heating of solar wind ions in inhomogeneous plasma with a 2.5D hybrid code. We include the expansion of the solar wind in an inhomogeneous plasma background, combined with the effects of a turbulent wave spectrum of Alfvénic fluctuations and initial ion-proton drifts. We study the influence of these effects on the perpendicular ion heating and cooling and on the spectrum of the magnetic fluctuations in the inhomogeneous background wind. We find that inhomogeneities in the plasma lead to enhanced heating compared to the homogenous solar wind, and the generation of significant power of oblique waves in the solar wind plasma. The cooling effect due to the expansion is not significant for super-Alfvénic drifts, and is diminished further when we include an inhomogeneous background density. We reproduce the ion temperature anisotropy seen in observations and previous models, which is present regardless of the perpendicular cooling due to solar wind expansion. We conclude that small scale inhomogeneities in the inner heliosphere can significantly affect resonant wave ion heating.

  9. First plasma of the A-PHOENIX electron cyclotron resonance ion source

    SciTech Connect

    Thuillier, T.; Lamy, T.; Latrasse, L.; Angot, J.

    2008-02-15

    A-PHOENIX is a new compact hybrid electron cyclotron resonance ion source using a large permanent magnet hexapole (1.92 T at the magnet surface) and high temperature superconducting Solenoids (3 T) to make min-vertical bar B vertical bar structure suitable for 28 GHz cw operation. The final assembly of the source was achieved at the end of June 2007. The first plasma of A-PHOENIX at 18 GHz was done on the 16th of August, 2007. The technological specificities of A-PHOENIX are presented. The large hexapole built is presented and experimental magnetic measurements show that it is nominal with respect to simulation. A fake plasma chamber prototype including thin iron inserts showed that the predicted radial magnetic confinement can be fulfilled up to 2.15 T at the plasma chamber wall. Scheduled planning of experiments until the end of 2008 is presented.

  10. An explanation for experimental observations of harmonic cyclotron emission induced by fast ions

    SciTech Connect

    Chen, K.R.; Horton, W.; Van Dam, J.W.

    1993-09-01

    An explanation, supported by numerical simulations and analytical theory, is given for the harmonic cyclotron emission induced by fast ions in tokamak plasmas - particular, for the emission observed at low harmonics in deuterium-deuterium md deuterium-tritium experiments in the Joint European Tokamak. We show that the first proton harmonic is one of the highest spectral peaks whereas the first alpha is weak. We also compare the relative spectral amplitudes of different harmonics. Our results axe consistent with the experimental observations. The simulations verify that the instabilities are caused by a weak relativistic mass effect. Simulation that a nonuniform magnetic field leads to no appreciable change in the growth and saturation amplitude of the waves.

  11. Ion cyclotron waves near L = 4.6 - A ground-satellite correlation study

    NASA Technical Reports Server (NTRS)

    Ludlow, G. R.; Hughes, W. J.; Engebretson, M. J.; Slavin, J. A.; Sugiura, M.

    1991-01-01

    Results are presented of the first ground-satellite correlation study of ion cyclotron wave events inside geosynchronous orbit. Several intervals are found during which waves at the same frequency were observed simultaneously by the DE 1 Goddard Space Flight Center Fluxgate Magnetometer and by the Air Force Geophysics Laboratory Magnetometer Network. This represents about 33 percent of the intervals during which waves were seen on the ground and DE 1 was in a favorable location (near the geomagnetic equator around L = 4.6) to observe the wave generation region. Three of seven simultaneous events showed a positive correlation when a detailed correlation analysis was performed. Peaks in the the cross-correlation function occurred at delays of 30-100 s and are interpreted as the group delay time of signals from space to the ground station. The small number of events seen in space during conjunction intervals results from the satellite's path missing the source region.

  12. Low-distortion detection system for frequency-swept ion cyclotron resonance spectrometry

    NASA Astrophysics Data System (ADS)

    Wise, M. B.; Freiser, B. S.

    1986-07-01

    A high-performance frequency-swept capacitance bridge detector for ion cyclotron resonance (ICR) spectrometry has been constructed in our laboratory. Although the basic design of the system is similar to that of previously reported bridge circuits, careful design, layout, construction, and component selection have resulted in excellent frequency-swept performance over a bandwidth of 15 kHz to 1 MHz. At a magnetic field strength of 1.0 T, this corresponds to a mass range of 15-1000 Daltons. Problems with base-line drift and frequency-dependent signal distortion common to many other designs have been significantly reduced. Circuit diagrams are included for all parts of the detector and frequency response curves have been included where appropriate. In addition, several simple circuit diagrams for support devices have also been included.

  13. Experimental evidence for the acceleration of thermal electrons by ion cyclotron waves in the magnetosphere

    NASA Technical Reports Server (NTRS)

    Norris, A. J.; Sojka, J. J.; Wrenn, G. L.; Johnson, J. F. E.; Cornilleau-Wehrlin, N.; Perraut, S.; Roux, A.

    1983-01-01

    Experimental evidence is presented for the acceleration of thermal electrons by large amplitude ion cyclotron waves (ICWs). The wave power in the ULF range near the helium gyrofrequency is compared with the distribution function of low energy electrons measured by GEOS satellite instruments. This comparison shows that electrons are accelerated near the geomagnetic equator along field lines, at times when the ICW energy is large and the cold plasma density is below a threshold value. It is suggested that these accelerated electrons can account for the ELF emissions, modulated at the ICW frequency, observed by Wehrlin (1981). A very efficient acceleration of thermal electrons along field lines results from other ULF events having frequencies close to the proton gyrofrequency. Evidence for this lies in the fact that medium energy protons having large temperature anisotropies in the 100-500 eV range are responsible for the ICW wave generation.

  14. Theory of mode conversion and wave damping near the ion-cyclotron frequency

    SciTech Connect

    Colestock, P.L.; Kashuba, R.J.

    1982-09-01

    Using a variational technique, a set of coupled model equations for the mode-conversion process near the ion-cyclotron frequency is derived. The system is truncated to first order in Larmor radius but includes the effects of explicit gradients and a poloidal field. From the equations a conservation rule is extracted which ensures conservation of total energy and provides an explicit expression for the wave damping in differential form. The equations are integrated numerically for the standard cases of fast waves incident from either the low- or high-field sides of the mode-conversion layer. The scaling of the damping processes is discussed and implications for current rf-heating experiments on the Princeton Large Torus are drawn.

  15. Ion Cyclotron Waves Observed in the Comet Halley: A New Look to Giotto Observations

    NASA Astrophysics Data System (ADS)

    Rodriguez-Martinez, M. R.; Blanco-Cano, X.; Aguilar-Rodriguez, E.; Haro-Corzo, S. S. A. R., Sr.; Arriaga-Contreras, V. V. R.

    2015-12-01

    Ion Cyclotron Waves (ICW) were observed with Giotto spacecraft. Magnetic field data have been analyzed in the past to determine the nature of ICW and compared with other comets, as Giacobini-Zinner and Grigg-Skjellerup. It is important to develop tools that allow re-analyze these data in order to know better the characteristics of these waves. In this work we have applied a Fast Fourier Transform (FFT) analysis in which we define the transverse and compressive powers for a better contrast and characterization of ICW. The information obtained will be presented through dynamic spectra in several time intervals. This tool will allow to explore the possibility to check the existence of Harmonic Mode Waves (HMW) of these waves. Finally, we use linear kinetic theory, using WHAMP code, in order to determine conditions for wave growth in a plasma resembling the regions where these waves were observed.

  16. Materials tests and analyses of Faraday shield tubes for ICRF (ion cyclotron resonant frequency) antennas

    SciTech Connect

    King, J.F.; Baity, F.W.; Hoffman, D.J.; Walls, J.C.; Taylor, D.J.

    1988-01-01

    The ion cyclotron resonant frequency (ICRF) antennas for heating fusion plasmas require careful analysis of the materials selected for the design and the successful fabrication of high integrity braze bonds. Graphite tiles are brazed to Inconel 625 Faraday shield tubes to protect the antenna from the plasma. The bond between the graphite and Inconel tube is difficult to achieve due to the different coefficients of thermal expansion. A 2-D stress analysis showed the graphite could be bonded to Inconel with a Ag-Cu-Ti braze alloy without cracking the graphite. Brazing procedures and nondestructive examination methods have been developed for these joints. This paper presents the results of our joining development and proof testing. 2 refs., 3 figs.

  17. Heterogeneously catalyzed hydrolysis of chlorine nitrate: Fourier-transform ion cyclotron resonance investigations of stratospheric chemistry

    NASA Astrophysics Data System (ADS)

    Schindler, Thomas; Berg, Christian; Niedner-Schatteburg, Gereon; Bondybey, Vladimir E.

    1996-03-01

    High resolution Fourier-transform ion cyclotron resonance (FT-ICR) mass spectroscopy is used to investigate reactions of large ionic water clusters H+(H2O)n and X-(H2O)n (n=1-100, X=O or OH). Reactions of the clusters with chlorine nitrate, important ``reservoir compound'' involved in the stratospheric ozone chemistry, are investigated to evaluate the importance of heterogeneously catalyzed reactions for ozone depletion. It is found that reactions of both cationic and anionic clusters result in effective hydrolysis of chlorine nitrate and return of the more active hypochlorous acid, HOCl into the gas phase. The chemistry of clusters is discussed, and its validity and relevance as a model for ``real life'' processes in the so-called polar stratospheric clouds (PSC's) is assessed.

  18. Ion cyclotron and lower hybrid arrays applicable to current drive in fusion reactors

    NASA Astrophysics Data System (ADS)

    Bosia, G.; Helou, W.; Goniche, M.; Hillaret, J.; Ragona, R.

    2014-02-01

    This paper presents concepts for Ion Cyclotron and Lower Hybrid Current Drive arrays applicable to fusion reactors and based on periodically loaded line power division. It is shown that, in large arrays, such as the ones proposed for fusion reactor applications, these schemes can offer, in principle, a number of practical advantages, compared with currently adopted ones, such as in-blanket operation at significantly reduced power density, lay out suitable for water cooling, single ended or balanced power feed, simple and load independent impedance matching In addition, a remote and accurate real time measurement of the complex impedance of all array elements as well as detection, location, and measurement of the complex admittance of a single arc occurring anywhere in the structure is possible.

  19. Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

    SciTech Connect

    Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F.; Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T.; Ban, G.; Celona, L.; Lunney, D.; Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O.; Kalvas, T.; and others

    2012-02-15

    As the most ambitious concept of isotope separation on line (ISOL) facility, EURISOL aims at producing unprecedented intensities of post-accelerated radioactive isotopes. Charge breeding, which transforms the charge state of radioactive beams from 1+ to an n+ charge state prior to post-acceleration, is a key technology which has to overcome the following challenges: high charge states for high energies, efficiency, rapidity and purity. On the roadmap to EURISOL, a dedicated R and D is being undertaken to push forward the frontiers of the present state-of-the-art techniques which use either electron cyclotron resonance or electron beam ion sources. We describe here the guidelines of this R and D.

  20. Studies of electromagnetic ion cyclotron waves using AMPTE/CCE and dynamics explorer

    NASA Technical Reports Server (NTRS)

    Erlandson, Robert E.

    1994-01-01

    The overall objective of this research is to investigate the generation and propagation of electromagnetic ion cyclotron (EMIC) waves in the frequency range from 0.2 to 5 Hz (Pc 1 frequency band). Data used in this research were acquired by the AMPTE/CCE, DE-1, and DE-2 satellites. One of the primary questions addressed in this research is the role which EMIC waves have on the transfer of energy from the equatorial magnetosphere to the ionosphere. The primary result from this research is that some fraction of EMIC waves, generated in the equatorial magnetosphere, are Landau damped in the ionosphere and are therefore a heat source for ionospheric electrons. This result as well as other results are summarized below.

  1. Progress in high-temperature oven development for 28 GHz electron cyclotron resonance ion source.

    PubMed

    Ohnishi, J; Higurashi, Y; Nakagawa, T

    2016-02-01

    We have been developing a high-temperature oven using UO2 in the 28 GHz superconducting electron cyclotron resonance ion source at RIKEN since 2013. A total of eleven on-line tests were performed. The longest operation time in a single test was 411 h, and the consumption rate of UO2 was approximately 2.4 mg/h. In these tests, we experienced several problems: the ejection hole of a crucible was blocked with UO2 and a crucible was damaged because of the reduction of tungsten strength at high temperature. In order to solve these problems, improvements to the crucible shape were made by simulations using ANSYS. PMID:26931927

  2. Nitrogen removal from plasma-facing components by ion cyclotron wall conditioning in TEXTOR

    NASA Astrophysics Data System (ADS)

    Carrasco, A. G.; Wauters, T.; Petersson, P.; Drenik, A.; Rubel, M.; Crombé, K.; Douai, D.; Fortuna, E.; Kogut, D.; Kreter, A.; Lyssoivan, A.; Möller, S.; Pisarek, M.; Vervier, M.

    2015-08-01

    The efficiency of ion cyclotron wall conditioning (ICWC) in the removal of nitrogen from plasma-facing components in TEXTOR was assessed. In two experiments the wall was loaded with nitrogen and subsequently cleaned by ICWC in deuterium and helium. The retention and removal of nitrogen was studied in-situ by means of mass spectrometry, and ex-situ by surface analysis of a set of graphite, tungsten and TZM plates installed on test limiter systems. 15N rare isotope was used as a marker. The results from the gas balance showed that about 25% of the retained nitrogen was removed after ICWC cleaning, whereas surface analysis of the plates based on ToF-HIERDA showed an increase of the deposited species after the cleaning. This indicates that during ICWC operation on carbon devices, nitrogen is not only pumped out but also transported to other locations on the wall. Additionally, deuterium surface content was studied before and after ICWC cleaning.

  3. Molecular and negative ion production by a standard electron cyclotron resonance ion source

    SciTech Connect

    Racz, R.; Biri, S.; Juhasz, Z.; Sulik, B.

    2012-02-15

    Molecular and negative ion beams, usually produced in special ion sources, play an increasingly important role in fundamental and applied atomic physics. The ATOMKI-ECRIS is a standard ECR ion source, designed to provide highly charged ion (HCI) plasmas and beams. In the present work, H{sup -}, O{sup -}, OH{sup -}, O{sub 2}{sup -}, C{sup -}, C{sub 60}{sup -} negative ions and H{sub 2}{sup +}, H{sub 3}{sup +}, OH{sup +}, H{sub 2}O{sup +}, H{sub 3}O{sup +}, O{sub 2}{sup +} positive molecular ions were generated in this HCI-ECRIS. Without any major modification in the source and without any commonly applied tricks (such as usage of cesium or magnetic filter), negative ion beams of several {mu}A and positive molecular ion beams in the mA range were successfully obtained.

  4. Electromagnetic Ion Cyclotron Waves near the Plasmapause: A CLUSTER Case Study

    NASA Astrophysics Data System (ADS)

    Fraser, B. J.; Liu, Y.; Menk, F. W.

    2011-12-01

    Electromagnetic ion cyclotron (EMIC) waves in the Pc1 ultra-low frequency wave band (0.2-5Hz) observed in the plasmasphere and magnetosphere are generated by micro-scale instabilities associated with keV energetic protons of ring current origin. This case study presents a typical EMIC wave event with frequency 1.8-3.5 Hz observed by the four Cluster spacecraft when passing through perigee (L ~ 4:2) and moving northward on 2 November 2001 around 08 MLT. The event occurred around the magnetic equatorial plane within magnetic latitude range ±18 degrees with a short duration of 50 minutes. The associated cold electron density data show the wave power was confined within the narrow shell of the plasmapause where the electron density gradient decreased from 30-80 cm-3 to 20 cm-3. The radial scale size of the wave region is estimated at ~ 0:77 Re. The wave polarization was dominantly left-handed around the equatorial region and inner side of source region, but appeared right-handed close to the outer edge of the plasmapause and at higher latitudes. The Poynting flux and minimum variance analysis indicate that the wave energy was mainly transported towards high latitudes though oblique propagation was seen around the equatorial region. Enhanced H+, He+ and O+ particle energy fluxes were seen during the wave event over energy range ~25eV-40keV. Unfortunately the lower energy cold plasma composition data were not available. These observations suggest the waves originated around the equatorial region in the high density outer plasmasphere-plasmapause which overlaps the ring current; ideal conditions for wave generation by the ion cyclotron instability.

  5. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

    SciTech Connect

    Ferracin, P.; Caspi, S.; Felice, H.; Leitner, D.; Lyneis, C. M.; Prestemon, S.; Sabbi, G. L.; Todd, D. S.

    2009-05-04

    Electron cyclotron resonance (ECR) ion sources are an essential component of heavy-ion accelerators. Over the past few decades advances in magnet technology and an improved understanding of the ECR ion source plasma physics have led to remarkable performance improvements of ECR ion sources. Currently third generation high field superconducting ECR ion sources operating at frequencies around 28 GHz are the state of the art ion injectors and several devices are either under commissioning or under design around the world. At the same time, the demand for increased intensities of highly charged heavy ions continues to grow, which makes the development of even higher performance ECR ion sources a necessity. To extend ECR ion sources to frequencies well above 28 GHz, new magnet technology will be needed in order to operate at higher field and force levels. The superconducting magnet program at LBNL has been developing high field superconducting magnets for particle accelerators based on Nb{sub 3}Sn superconducting technology for several years. At the moment, Nb{sub 3}Sn is the only practical conductor capable of operating at the 15 T field level in the relevant configurations. Recent design studies have been focused on the possibility of using Nb{sub 3}Sn in the next generation of ECR ion sources. In the past, LBNL has worked on the VENUS ECR, a 28 GHz source with solenoids and a sextupole made with NbTi operating at fields of 6-7 T. VENUS has now been operating since 2004. We present in this paper the design of a Nb{sub 3}Sn ECR ion source optimized to operate at an rf frequency of 56 GHz with conductor peak fields of 13-15 T. Because of the brittleness and strain sensitivity of Nb{sub 3}Sn- , particular care is required in the design of the magnet support structure, which must be capable of providing support to the coils without overstressing the conductor. In this paper, we present the main features of the support structure, featuring an external aluminum shell

  6. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources.

    PubMed

    Ferracin, P; Caspi, S; Felice, H; Leitner, D; Lyneis, C M; Prestemon, S; Sabbi, G L; Todd, D S

    2010-02-01

    Electron cyclotron resonance (ECR) ion sources are an essential component of heavy-ion accelerators. Over the past few decades advances in magnet technology and an improved understanding of the ECR ion source plasma physics have led to remarkable performance improvements of ECR ion sources. Currently third generation high field superconducting ECR ion sources operating at frequencies around 28 GHz are the state of the art ion injectors and several devices are either under commissioning or under design around the world. At the same time, the demand for increased intensities of highly charged heavy ions continues to grow, which makes the development of even higher performance ECR ion sources a necessity. To extend ECR ion sources to frequencies well above 28 GHz, new magnet technology will be needed in order to operate at higher field and force levels. The superconducting magnet program at LBNL has been developing high field superconducting magnets for particle accelerators based on Nb(3)Sn superconducting technology for several years. At the moment, Nb(3)Sn is the only practical conductor capable of operating at the 15 T field level in the relevant configurations. Recent design studies have been focused on the possibility of using Nb(3)Sn in the next generation of ECR ion sources. In the past, LBNL has worked on the VENUS ECR, a 28 GHz source with solenoids and a sextupole made with NbTi operating at fields of 6-7 T. VENUS has now been operating since 2004. We present in this paper the design of a Nb(3)Sn ECR ion source optimized to operate at an rf frequency of 56 GHz with conductor peak fields of 13-15 T. Because of the brittleness and strain sensitivity of Nb(3)Sn, particular care is required in the design of the magnet support structure, which must be capable of providing support to the coils without overstressing the conductor. In this paper, we present the main features of the support structure, featuring an external aluminum shell pretensioned with water

  7. Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source

    SciTech Connect

    Roychowdhury, P. Mishra, L.; Kewlani, H.; Mittal, K. C.; Patil, D. S.

    2014-03-15

    A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20–40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, −2 to −4 kV, and 0 kV, respectively. The total ion beam current of 30–40 mA is recorded on Faraday cup at 40 keV of beam energy at 600–1000 W of microwave power, 800–1000 G axial magnetic field and (1.2–3.9) × 10{sup −3} mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

  8. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    NASA Astrophysics Data System (ADS)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  9. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results.

    PubMed

    Anupriya; Jones, Chad A; Dearden, David V

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy. Graphical Abstract ᅟ. PMID:27220844

  10. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    NASA Astrophysics Data System (ADS)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-05-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  11. Particle-in-cell simulations of the excitation mechanism for fusion-product-driven ion cyclotron emission from tokamaks

    NASA Astrophysics Data System (ADS)

    Dendy, Richard; Cook, James; Chapman, Sandra

    2009-11-01

    Suprathermal ion cyclotron emission (ICE) was the first collective radiative instability, driven by fusion products, observed on JET and TFTR. Strong emission occurs at sequential cyclotron harmonics of the energetic ion population at the outer mid-plane. Its intensity scales linearly with fusion reactivity, including its time evolution during a discharge. The emission mechanism is probably the magnetoacoustic cyclotron instability (MCI), involving resonance between: fast Alfv'en waves; cyclotron harmonic waves supported by the energetic particle population and by the background thermal plasma; and a subset of the centrally born fusion products, just inside the trapped-passing boundary, whose drift orbits make large radial excursions. The linear growth rate of the MCI has been intensively studied analytically, and yields good agreement with several key observational features of ICE. To address outstanding issues in the nonlinear ICE regime, we have developed a particle-in-cell code which self-consistently evolves electron and multi-species ion macroparticles and the electromagnetic field. We focus on the growth rate of the MCI, as it evolves from the linear into the nonlinear regime for JET-like parameters.

  12. Synchrotrons in cyclotron territory

    SciTech Connect

    Clark, D.J.; Gough, R.A.

    1986-10-01

    Synchrotrons and cyclotrons have an overlap in their particle and energy ranges. In proton radiotherapy, synchrotrons are proposed at 250 MeV, an energy usually served by cyclotrons. Heavy ion therapy has been synchrotron territory, but cyclotrons may be competitive. In nuclear science, heavy ion synchrotrons can be used in the cyclotron energy range of 10-200 MeV/u. Storage rings are planned to increase the flexibility of several cyclotrons. For atomic physics research, several storage rings are under construction for the energy range of 10 MeV/u and below.

  13. Recent development of RIKEN 28 GHz superconducting electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Higurashi, Y.; Ohnishi, J.; Ozeki, K.; Kidera, M.; Nakagawa, T.

    2014-02-01

    Over the past two years, we have tried to improve the performance of the RIKEN superconducting electron cyclotron resonance ion source using several methods. For the production of U vapor, we chose the sputtering method because it is possible to install a large amount of material inside the plasma chamber and thus achieve long-term operation without a break, although it is assumed that the beam intensity is weaker than in the oven technique. We also used an aluminum chamber instead of a stainless steel one. Using these methods, we successfully produced ˜180 eμA of U35+ and ˜230 eμA of U33+ at the injected radio frequency (RF) power of ˜4 kW (28 GHz). Very recently, to further increase the beam intensity of U35+, we have started to develop a high temperature oven and have successfully produced a highly charged U ion beam. In this contribution, we report on the beam intensity of highly charged U ions as a function of various parameters (RF power and sputtering voltage) and discuss the effects of these parameters on the beam stability in detail.

  14. Recondensation performance of liquid helium cryostat for a 28 GHz electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Choi, Seyong; Lee, Byoung-Seob; Park, Jin Yong; Ok, Jung-Woo; Shin, Chang Seouk; Yoon, Jang-Hee; Won, Mi-Sook; Kim, Byoung-Chul

    2014-02-01

    Cryostat performance is essential for the stable operation of a superconducting magnet. A closed-cycle liquid helium cryostat was adopted for use for a superconducting electron cyclotron resonance (ECR) ion source by recondensing liquid helium vapor. The goal was to maintain the liquid helium filled reservoir at a constant level without transferring any liquid helium during the normal operation of the ECR ion source. To accomplish this, Gifford-McMahon (GM) refrigerators, which have two cold heads, were installed on the top of the cryostat. The cooling power of the GM cryocooler is 1.5 W at the second stage and 50 W at the first stage. Each stage was connected to the liquid helium reservoir, a radiation shield including high-Tc current lead, and related items. Before commissioning the ECR ion source, a preliminary evaluation of the recondensation performance was carried out with the magnet in partial operation. The design of the cryostat, its fabrication, and the experimental results are reported.

  15. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source.

    PubMed

    Kim, June Young; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae; Hwang, Y S

    2016-02-01

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H(-) ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H(-) ion generation in volume-produced negative hydrogen ion sources. PMID:26931999

  16. Bias voltage and corrosion effects in rf ovens in electron cyclotron resonance ion source

    SciTech Connect

    Cavenago, M.; Galata, A.; Kulevoy, T.; Petrenko, S.

    2006-03-15

    Induction-heated miniaturized ovens were successfully coupled to electron cyclotron resonance ion sources for the production of copper and silver ion beams. Experiments with tin and praseodymium ion beams are here presented; some preliminary tests for titanium are also described. In the latter case (and in general over a 1800 K temperature) a molybdenum rf coil is used. The results with tin show currents comparable to silver (after obvious correction for isotopic abundance), with some operational difficulty due to frequent pouring of liquid sample out of crucible. The effects of a bias voltage V{sub b} applied to the Sn sample are reported. Cold sputter probes are compared. The results with praseodymium show lower currents than tin and large sensitivity to mixing gas used: nitrogen emerged as the best compromise against oxygen (possibly because this oxidizes the sample) and against inert noble gases. Optimal bias voltage for Pr (V{sub b} from -50 to -300 V) is much smaller than for silver (V{sub b} congruent with -1 kV)

  17. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source

    NASA Astrophysics Data System (ADS)

    Kim, June Young; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae; Hwang, Y. S.

    2016-02-01

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H- ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ˜4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H- ion generation in volume-produced negative hydrogen ion sources.

  18. Helicon Plasma Injector and Ion Cyclotron Acceleration Development in the VASIMR Experiment

    NASA Technical Reports Server (NTRS)

    Squire, Jared P.; Chang, Franklin R.; Jacobson, Verlin T.; McCaskill, Greg E.; Bengtson, Roger D.; Goulding, Richard H.

    2000-01-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) radio frequency (rf) waves both produce the plasma and then accelerate the ions. The plasma production is done by action of helicon waves. These waves are circular polarized waves in the direction of the electron gyromotion. The ion acceleration is performed by ion cyclotron resonant frequency (ICRF) acceleration. The Advanced Space Propulsion Laboratory (ASPL) is actively developing efficient helicon plasma production and ICRF acceleration. The VASIMR experimental device at the ASPL is called VX-10. It is configured to demonstrate the plasma production and acceleration at the 10kW level to support a space flight demonstration design. The VX-10 consists of three electromagnets integrated into a vacuum chamber that produce magnetic fields up to 0.5 Tesla. Magnetic field shaping is achieved by independent magnet current control and placement of the magnets. We have generated both helium and hydrogen high density (>10(exp 18) cu m) discharges with the helicon source. ICRF experiments are underway. This paper describes the VX-10 device, presents recent results and discusses future plans.

  19. Ion cyclotron range of frequencies heating and current drive in deuterium-tritium plasmas

    NASA Astrophysics Data System (ADS)

    Phillips, C. K.; Bell, M. G.; Bell, R.; Bretz, N.; Budny, R. V.; Darrow, D. S.; Grek, B.; Hammett, G.; Hosea, J. C.; Hsuan, H.; Ignat, D.; Majeski, R.; Mazzucato, E.; Nazikian, R.; Park, H.; Rogers, J. H.; Schilling, G.; Stevens, J. E.; Synakowski, E.; Taylor, G.; Wilson, J. R.; Zarnstorff, M. C.; Zweben, S. J.; Bush, C. E.; Goldfinger, R.; Jaeger, E. F.; Murakami, M.; Rasmussen, D.; Bettenhausen, M.; Lam, N. T.; Scharer, J.; Sund, R.; Sauter, O.

    1995-06-01

    The first experiments utilizing high-power radio waves in the ion cyclotron range of frequencies to heat deuterium-tritium (D-T) plasmas have been completed on the Tokamak Fusion Test Reactor [Fusion Technol. 21, 13 (1992)]. Results from the initial series of experiments have demonstrated efficient core second harmonic tritium (2ΩT) heating in parameter regimes approaching those anticipated for the International Thermonuclear Experimental Reactor [D. E. Post, Plasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 13th International Conference, Washington, DC, 1990 (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 239]. Observations are consistent with modeling predictions for these plasmas. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves has been observed in D-T, deuterium-deuterium (D-D), and deuterium-helium-4 (D-4He) plasmas with high concentrations of minority helium-3 (3He) (n3He/ne≳10%). Mode conversion current drive in D-T plasmas was simulated with experiments conducted in D-3He-4He plasmas. Results show a directed propagation of the mode converted ion Bernstein waves, in correlation with the antenna phasing.

  20. Electrostatic ion (hydrogen) cyclotron and ion acoustic wave instabilities in regions of upward field-aligned current and upward ion beams

    NASA Astrophysics Data System (ADS)

    Bergmann, R.

    1984-02-01

    An investigation is made into the stability of electrostatic hydrogen ion cyclotron and ion acoustic waves in a model plasma where an ion beam, population 2, and oppositely directed drifting electrons pass through a stationary ion background, population 1. The excited wave properties are then compared with the characteristics of the unstable modes observed on the S3-3 satellite. Three temperature regimes are studied: (1) Te greater than Ti2 much greater than Ti1, (2) Ti2 greater than Te not less than Ti1, and (3) Te approximately equal to Ti1 greater than Ti2. It is found that the ion beam acts as a free energy source only in regime 1. This regime is also highly unstable to the electrons as a free energy source. Unstable modes in regimes 2 and 3 seem to best satisfy the electrostatic hydrogen cyclotron wave (EHC) properties at 1 earth radius. For these cases the electrons are the free energy source, the beam supplies damping.

  1. Self-Consistent Model of Magnetospheric Ring Current and Electromagnetic Ion Cyclotron Waves: The May 2-7, 1998, Storm

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.; Jordanova, V. K.

    2003-01-01

    Complete description of a self-consistent model for magnetospheric ring current interacting with electromagnetic ion cyclotron waves is presented. The model is based on the system of two kinetic equations; one equation describes the ring current ion dynamics, and another equation describes the wave evolution. The effects on ring current ions interacting with electromagnetic ion cyclotron waves, and back on waves, are considered self-consistently by solving both equations on a global magnetospheric scale under non steady-state conditions. In the paper by Khazanov et al. [2002] this self-consistent model has only been shortly outlined, and discussions of many the model related details have been omitted. For example, in present study for the first time a new algorithm for numerical finding of the resonant numbers for quasilinear wave-particle interaction is described, or it is demonstrated that in order to describe quasilinear interaction in a multi-ion thermal plasma correctly, both e and He(+) modes of electromagnetic ion cyclotron waves should be employed. The developed model is used to simulate the entire May 2-7, 1998 storm period. Trapped number fluxes of the ring current protons are calculated and presented along with their comparison with the data measured by the 3D hot plasma instrument Polar/HYDRA. Examining of the wave (MLT, L shell) distributions produced during the storm progress reveals an essential intensification of the wave emissions in about two days after main phase of storm. This result is well consistent with the earlier ground-based observations. Also the theoretical shapes and the occurrence rates for power spectral densities of electromagnetic ion cyclotron waves are studied. It is found that in about 2 days after the storm main phase on May 4, mainly non Gaussian shapes of power spectral densities are produced.

  2. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    SciTech Connect

    Falabella, S.

    1988-05-11

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs.

  3. Towards analytically useful two-dimensional Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    van Agthoven, Maria A; Delsuc, Marc-André; Bodenhausen, Geoffrey; Rolando, Christian

    2013-01-01

    Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) achieves high resolution and mass accuracy, allowing the identification of the raw chemical formulae of ions in complex samples. Using ion isolation and fragmentation (MS/MS), we can obtain more structural information, but MS/MS is time- and sample-consuming because each ion must be isolated before fragmentation. In 1987, Pfändler et al. proposed an experiment for 2D FT-ICR MS in order to fragment ions without isolating them and to visualize the fragmentations of complex samples in a single 2D mass spectrum, like 2D NMR spectroscopy. Because of limitations of electronics and computers, few studies have been conducted with this technique. The improvement of modern computers and the use of digital electronics for FT-ICR hardware now make it possible to acquire 2D mass spectra over a broad mass range. The original experiments used in-cell collision-induced dissociation, which caused a loss of resolution. Gas-free fragmentation modes such as infrared multiphoton dissociation and electron capture dissociation allow one to measure high-resolution 2D mass spectra. Consequently, there is renewed interest to develop 2D FT-ICR MS into an efficient analytical method. Improvements introduced in 2D NMR spectroscopy can also be transposed to 2D FT-ICR MS. We describe the history of 2D FT-ICR MS, introduce recent improvements, and present analytical applications to map the fragmentation of peptides. Finally, we provide a glossary which defines a few keywords for the 2D FT-ICR MS field. PMID:23076397

  4. Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Marto, J A; White, F M; Seldomridge, S; Marshall, A G

    1995-11-01

    Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode. PMID:8633761

  5. The effect of plasma shear flow on drift Alfven instabilities of a finite beta plasma and on anomalous heating of ions by ion cyclotron turbulence

    NASA Astrophysics Data System (ADS)

    Jo, Young Hyun; Lee, Hae June; Mikhailenko, Vladimir V.; Mikhailenko, Vladimir S.

    2016-01-01

    It was derived that the drift-Alfven instabilities with the shear flow parallel to the magnetic field have significant difference from the drift-Alfven instabilities of a shearless plasma when the ion temperature is comparable with electron temperature for a finite plasma beta. The velocity shear not only modifies the frequency and the growth rate of the known drift-Alfven instability, which develops due to the inverse electron Landau damping, but also triggers a combined effect of the velocity shear and the inverse ion Landau damping, which manifests the development of the ion kinetic shear-flow-driven drift-Alfven instability. The excited unstable waves have the phase velocities along the magnetic field comparable with the ion thermal velocity, and the growth rate is comparable with the frequency. The development of this instability may be the efficient mechanism of the ion energization in shear flows. The levels of the drift--Alfven turbulence, resulted from the development of both instabilities, are determined from the renormalized nonlinear dispersion equation, which accounts for the nonlinear effect of the scattering of ions by the electromagnetic turbulence. The renormalized quasilinear equation for the ion distribution function, which accounts for the same effect of the scattering of ions by electromagnetic turbulence, is derived and employed for the analysis of the ion viscosity and ions heating, resulted from the interactions of ions with drift-Alfven turbulence. In the same way, the phenomena of the ion cyclotron turbulence and anomalous anisotropic heating of ions by ion cyclotron plasma turbulence has numerous practical applications in physics of the near-Earth space plasmas. Using the methodology of the shearing modes, the kinetic theory of the ion cyclotron turbulence of the plasma with transverse current with strong velocity shear has been developed.

  6. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    SciTech Connect

    Tarvainen, Ollie A; Kurennoy, Sergey

    2008-01-01

    A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

  7. New method for comprehensive detection of chemical warfare agents using an electron-cyclotron-resonance ion-source mass spectrometer.

    PubMed

    Kidera, Masanori; Seto, Yasuo; Takahashi, Kazuya; Enomoto, Shuichi; Kishi, Shintaro; Makita, Mika; Nagamatsu, Tsuyoshi; Tanaka, Tatsuhiko; Toda, Masayoshi

    2011-03-01

    We developed a detection technology for vapor forms of chemical warfare agents (CWAs) with an element analysis system using an electron cyclotron resonance ion source. After the vapor sample was introduced directly into the ion source, the molecular material was decomposed into elements using electron cyclotron resonance plasma and ionized. The following CWAs and stimulants were examined: diisopropyl fluorophosphonate (DFP), 2-chloroethylethylsulfide (2CEES), cyanogen chloride (CNCl), and hydrogen cyanide (HCN). The type of chemical warfare agents, specifically, whether it was a nerve agent, blister agent, blood agent, or choking agent, could be determined by measuring the quantities of the monatomic ions or CN(+) using mass spectrometry. It was possible to detect gaseous CWAs that could not be detected by a conventional mass spectrometer. The distribution of electron temperature in the plasma could be closely controlled by adjusting the input power of the microwaves used to generate the electron cyclotron resonance plasma, and the target compounds could be detected as molecular ions or fragment ions, enabling identification of the target agents. PMID:21242103

  8. Particle-in-cell Simulations of Continuously Driven Mirror and Ion Cyclotron Instabilities in High Beta Astrophysical and Heliospheric Plasmas

    NASA Astrophysics Data System (ADS)

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel

    2015-02-01

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ~ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ~ 0.3 langBrang in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ~ 0.1 langBrang, the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  9. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    SciTech Connect

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel E-mail: eliot@berkeley.edu

    2015-02-10

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p {sub ∥} and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes.

  10. New method for comprehensive detection of chemical warfare agents using an electron-cyclotron-resonance ion-source mass spectrometer

    NASA Astrophysics Data System (ADS)

    Kidera, Masanori; Seto, Yasuo; Takahashi, Kazuya; Enomoto, Shuichi; Kishi, Shintaro; Makita, Mika; Nagamatsu, Tsuyoshi; Tanaka, Tatsuhiko; Toda, Masayoshi

    2011-03-01

    We developed a detection technology for vapor forms of chemical warfare agents (CWAs) with an element analysis system using an electron cyclotron resonance ion source. After the vapor sample was introduced directly into the ion source, the molecular material was decomposed into elements using electron cyclotron resonance plasma and ionized. The following CWAs and stimulants were examined: diisopropyl fluorophosphonate (DFP), 2-chloroethylethylsulfide (2CEES), cyanogen chloride (CNCl), and hydrogen cyanide (HCN). The type of chemical warfare agents, specifically, whether it was a nerve agent, blister agent, blood agent, or choking agent, could be determined by measuring the quantities of the monatomic ions or CN + using mass spectrometry. It was possible to detect gaseous CWAs that could not be detected by a conventional mass spectrometer. The distribution of electron temperature in the plasma could be closely controlled by adjusting the input power of the microwaves used to generate the electron cyclotron resonance plasma, and the target compounds could be detected as molecular ions or fragment ions, enabling identification of the target agents.

  11. Tailored Noise Waveform/ Collision-Induced Dissociation of Ions Stored in a Linear Ion Trap Combined with Liquid Chromatography/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

    SciTech Connect

    Vilkov, Andrey N.; Bogdanov, Bogdan; Pasa-Tolic, Liljiana; Prior, David C.; Anderson, Gordon A.; Masselon, Christophe D.; Moore, Ronald J.; Smith, Richard D.

    2004-11-01

    A new collision-induced dissociation (CID) technique based on broadband tailored noise waveform (TNW) excitation of ions stored in a linear ion trap has been developed. In comparison with the conventional sustained off-resonance irradiation (SORI) CID method commonly used in Fourier transform ion cyclotron resonance mass spectrometry, this MS/MS technique increases throughput by eliminating the long pump-down delay associated with gas introduction into the high vacuum ICR cell region. In addition, the TNW-CID method speeds spectrum acquisition since it does not require Fourier transformation, calculation of resonant frequencies and generation of the excitation waveforms. We demonstrate TNW-CID coupled with on-line capillary reverse phase liquid chromatography separations for identification of peptides. The experimental results are compared with data obtained using conventional quadrupole ion trap MS/MS and SORI-CID MS/MS in an ICR cell.

  12. Analysis of saturated hydrocarbons by redox reaction with negative-ion electrospray Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Zhou, Xibin; Shi, Quan; Zhang, Yahe; Zhao, Suoqi; Zhang, Rui; Chung, Keng H; Xu, Chunming

    2012-04-01

    A novel technique was developed for characterization of saturated hydrocarbons. Linear alkanes were selectively oxidized to ketones by ruthenium ion catalyzed oxidation (RICO). Branched and cyclic alkanes were oxidized to alcohols and ketones. The ketones were then reduced to alcohols by lithium aluminum hydride (LiAlH(4)). The monohydric alcohols (O(1)) in the products obtained from the RICO and RICO-LiAlH(4) reduction reactions were characterized using negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) for identification of iso-paraffins, acyclic paraffins and cyclic paraffins. Various model saturated compounds were used to determine the RICO reaction and ionization selectivity. The results from the FTICR MS analysis on the petroleum distillates derived saturated fraction were in agreement with those from field ionization gas chromatography time-of-flight mass spectrometry (FI GC-TOF MS) analysis. The technique was also used to characterize a petroleum vacuum residue (VR) derived saturates. The results showed that the saturated molecules in the VR contained up to 11 cyclic rings, and the maximum carbon number was up to 92. PMID:22424498

  13. Development of a compact electron-cyclotron-resonance ion source for high-energy carbon-ion therapy

    NASA Astrophysics Data System (ADS)

    Muramatsu, M.; Kitagawa, A.; Sakamoto, Y.; Sato, S.; Sato, Y.; Ogawa, Hirotsugu; Yamada, S.; Ogawa, Hiroyuki; Yoshida, Y.; Drentje, A. G.

    2005-11-01

    Ion sources for medical facilities should have characteristics of easy maintenance, low electric power consumption, good stability, and long operation time without problems (one year or longer). For this, a 10GHz compact electron-cyclotron-resonance ion source with all-permanent magnets (Kei2 source) was developed. The maximum mirror magnetic fields on the beam axis are 0.59T at the extraction side and 0.87T at the gas-injection side, while the minimum B strength is 0.25T. These parameters have been optimized for the production of C4+ based on the experience at the 10GHz NIRS-ECR ion source and a previous prototype compact source (Kei source). The Kei2 source has a diameter of 320mm and a length of 295mm. The beam intensity of C4+ was obtained to be 530μA under an extraction voltage of 40kV. The beam stability was better than 6% at C4+ of 280μA during 90h with no adjustment of the operation parameters. The details of the design and beam tests of the source are described in this paper.

  14. A double-layer based model of ion confinement in electron cyclotron resonance ion source

    SciTech Connect

    Mascali, D. Neri, L.; Celona, L.; Castro, G.; Gammino, S.; Ciavola, G.; Torrisi, G.; Università Mediterranea di Reggio Calabria, Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile, Via Graziella, I-89100 Reggio Calabria ; Sorbello, G.; Università degli Studi di Catania, Dipartimento di Ingegneria Elettrica Elettronica ed Informatica, Viale Andrea Doria 6, 95125 Catania

    2014-02-15

    The paper proposes a new model of ion confinement in ECRIS, which can be easily generalized to any magnetic configuration characterized by closed magnetic surfaces. Traditionally, ion confinement in B-min configurations is ascribed to a negative potential dip due to superhot electrons, adiabatically confined by the magneto-static field. However, kinetic simulations including RF heating affected by cavity modes structures indicate that high energy electrons populate just a thin slab overlapping the ECR layer, while their density drops down of more than one order of magnitude outside. Ions, instead, diffuse across the electron layer due to their high collisionality. This is the proper physical condition to establish a double-layer (DL) configuration which self-consistently originates a potential barrier; this “barrier” confines the ions inside the plasma core surrounded by the ECR surface. The paper will describe a simplified ion confinement model based on plasma density non-homogeneity and DL formation.

  15. A gain and bandwidth enhanced transimpedance preamplifier for Fourier-transform ion cyclotron resonance mass spectrometry

    SciTech Connect

    Lin, Tzu-Yung; Green, Roger J.; O'Connor, Peter B.

    2011-12-15

    The nature of the ion signal from a 12-T Fourier-transform ion cyclotron resonance mass spectrometer and the electronic noise were studied to further understand the electronic detection limit. At minimal cost, a new transimpedance preamplifier was designed, computer simulated, built, and tested. The preamplifier design pushes the electronic signal-to-noise performance at room temperature to the limit, because of its enhanced tolerance of the capacitance of the detection device, lower intrinsic noise, and larger flat mid-band gain (input current noise spectral density of around 1 pA/{radical}(Hz) when the transimpedance is about 85 dB{Omega}). The designed preamplifier has a bandwidth of {approx}3 kHz to 10 MHz, which corresponds to the mass-to-charge ratio, m/z, of approximately 18 to 61 k at 12 T. The transimpedance and the bandwidth can be easily adjusted by changing the value of passive components. The feedback limitation of the circuit is discussed. With the maximum possible transimpedance of 5.3 M{Omega} when using an 0402 surface mount resistor, the preamplifier was estimated to be able to detect {approx}110 charges in a single scan.

  16. High-Power Arctic Lidar for observations of Sodium layer and Calcium Ion Cyclotron Resonance Heating

    NASA Astrophysics Data System (ADS)

    Wuerker, R. F.; Foley, J.; Kidd, P.; Wong, A. Y.

    1998-11-01

    The UCLA HIPAS Observatory is located at 64o 54' 22"N, 146o 50' 33" W. It passes under the auroral oval, has a 2.7 m diameter liquid mirror collector (LMT), and two bistatic laser illuminators; a Doubled YAG pumped dye laser and a Doubled (tunable) Alexandrite laser. The first emits 0.1 J - 10 ns pulses at 590nm (Na) at 20 Hz. The second laser emits 0.15 J -10 ns pulses at 393 nm (Ca+) and 391.4 nm (N2) at 10 Hz. New sporadic sodium layers have been observed during the passage of the electrojet and auroras in periods of 20-30 seconds, indicating that sodium is liberated from micrometeors during auroral precipitations. The Laser Induced Fluorescence techniques will be used to observe the acceleration of the Ca+ ions when they are driven by the 80 MW (ERP) 2.85MHz RF array, modulated at the Ca+ ion Cyclotron Frequency. 1. Ionospheric Modifaction and Enviromental Research in the Auroral Region in Plasma Science and the Environment. Publisher: AIP Press, Woodbury, NY. Editors: W. Manheimer, L. Sugiyama, T. Stix; Chapter 3, pgs. 41-75, 1997. Research supported by ONR N00014-96-C-0040

  17. Electromagnetic ion cyclotron waves in the inner magnetosphere with a losscone proton distribution

    NASA Astrophysics Data System (ADS)

    Singh, Satyavir; Omura, Yoshiharu

    2016-07-01

    Electromagnetic ion cyclotron (EMIC) waves are studied in the inner magnetospheric plasma. The plasma is assumed to have five components, i.e., electrons, cold and hot protons, singly charged helium and oxygen ions. The hot protons are assumed to have an anisotropic losscone distribution particle distribution. The numerical results are obtained using KUPDAP (Kyoto University Plasma Dispersion Analysis Package), a full dispersion solver developed at Kyoto University. The hot plasma dispersion relation and polarizations of EMIC waves in oblique propagation are very complex. Although we find that nonlinear wave growth process is dominant near the equatorial region generating EMIC rising tone emissions, the propagation characteristics of the emissions such as linear growth/damping rates, variation of polarizations, and Poynting vectors in the presence of energetic protons have not been studied quantitatively.The growth/damping of oxygen, helium, and proton bands and higher harmonics of the EMIC waves are studied. The findings from our model are applied to EMIC wave observations in the inner magnetosphere by the Cluster spacecraft.

  18. Microgan electron cyclotron resonance ion source in a Van de Graaff accelerator terminala)

    NASA Astrophysics Data System (ADS)

    Gaubert, G.; Bieth, C.; Bougy, W.; Brionne, N.; Donzel, X.; Sineau, A.; Vallerand, C.; Villari, A. C. C.; Chaves, C.; Gamboni, T.; Geerts, W.; Giorginis, G.; Lövestam, G.; Mondelaers, W.

    2012-02-01

    The Van de Graaff accelerator at IRMM works since many years providing proton, deuteron, and helium beams for nuclear data measurements. The original ion source was of RF type with quartz bottle. This kind of source, as well known, needs regular maintenance for which the accelerator tank must be completely opened. The heavy usage at high currents of the IRMM accelerator necessitated an opening about once every month. In 2010, the full permanent magnet Microgan electron cyclotron resonance (ECR) ion source from PANTECHNIK was installed into a new terminal platform together with a solid state amplifier of 50 W, a dedicated dosing system for 4 gases (with respective gas bottles H2, D2, He, and Ar), and a set of dedicated power supplies and electronic devices for the remote tuning of the source. The new system shows a very stable behaviour of the produced beam allowing running the Van de Graaf without maintenance for several months. This contribution will describe the full installed system in details (working at high pressure in the terminal, spark effects, and optic of the extraction), as well as beam results in dc or pulsed mode.

  19. The role of Shabansky orbits in compression-related electromagnetic ion cyclotron wave growth

    NASA Astrophysics Data System (ADS)

    McCollough, J. P.; Elkington, S. R.; Baker, D. N.

    2012-01-01

    Electromagnetic ion cyclotron waves at high L values near local noon are often found to be related to magnetospheric compression events. These waves arise from temperature anisotropies in trapped warm plasma populations. There are several possible mechanisms that can generate these temperature anisotropies, including both energizing and nonenergizing processes. In this work we investigate a nonenergizing process arising from dayside bifurcated magnetic field minima. There are two kinds of behavior particles undergo in the presence of bifurcated minima: particles with high initial equatorial pitch angles (EPAs) are forced to execute so-called Shabansky orbits and mirror at high latitudes without passing through the equator, while those with lower initial EPAs will pass through the equator with higher EPAs than before; as a result, perpendicular energies near the equator increase at the cost of parallel energies. By using a 3-D particle tracing code in a tunable analytic compressed-dipole field, we explore the effects of Shabansky orbits on the anisotropy of the warm plasma and contrast with the anisotropy resulting from drift shell splitting. We show that Shabansky orbits are an independent source of temperature anisotropy for warm dayside ions.

  20. A gain and bandwidth enhanced transimpedance preamplifier for Fourier-transform ion cyclotron resonance mass spectrometry

    PubMed Central

    Lin, Tzu-Yung; Green, Roger J.; O'Connor, Peter B.

    2011-01-01

    The nature of the ion signal from a 12-T Fourier-transform ion cyclotron resonance mass spectrometer and the electronic noise were studied to further understand the electronic detection limit. At minimal cost, a new transimpedance preamplifier was designed, computer simulated, built, and tested. The preamplifier design pushes the electronic signal-to-noise performance at room temperature to the limit, because of its enhanced tolerance of the capacitance of the detection device, lower intrinsic noise, and larger flat mid-band gain (input current noise spectral density of around 1 pA/\\documentclass[12pt]{minimal}\\begin{document}$\\sqrt{\\mbox{Hz}}$\\end{document}Hz when the transimpedance is about 85 dBΩ). The designed preamplifier has a bandwidth of ∼3 kHz to 10 MHz, which corresponds to the mass-to-charge ratio, m/z, of approximately 18 to 61 k at 12 T. The transimpedance and the bandwidth can be easily adjusted by changing the value of passive components. The feedback limitation of the circuit is discussed. With the maximum possible transimpedance of 5.3 MΩ when using an 0402 surface mount resistor, the preamplifier was estimated to be able to detect ∼110 charges in a single scan. PMID:22225232

  1. First Signal on the Cryogenic Fourier-Transform Ion Cyclotron Resonance Mass Spectrometer

    PubMed Central

    Lin, Cheng; Mathur, Raman; Aizikov, Kostantin; O'Connor, Peter B.

    2009-01-01

    The construction and achievement of the first signal on a cryogenic Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR-MS) are reported here, demonstrating proof-of-concept of this new instrument design. Building the FTICR cell into the cold bore of a superconducting magnet provided advantages over conventional warm bore design. At 4.2 K, the vacuum system cryopumps itself, thus removing the requirement for a large bore to achieve the desired pumping speed for maintaining base pressure. Furthermore, because the bore diameter has been reduced, the amount of magnet wire needed to achieve high field and homogeneity was also reduced, greatly decreasing the cost/Tesla of the magnet. The current instrument implements an actively shielded 14-Tesla magnet of vertical design with an external matrix assisted laser desorption/ionization (MALDI) source. The first signal was obtained by detecting the laser desorbed/ionized (LDI) C60+• ions, with the magnet at 7 Tesla, unshimmed, and the preamplifier mounted outside of the vacuum chamber at room temperature. A subsequent experiment done with the magnet at 14 Tesla and properly shimmed produced a C60 spectrum showing ∼350,000 resolving power at m/z ∼720. Increased magnetic field strength improves many FTMS performance parameters simultaneously, particularly mass resolving power and accuracy. PMID:17931882

  2. ION CYCLOTRON WAVES IN THE SOLAR WIND OBSERVED BY STEREO NEAR 1 AU

    SciTech Connect

    Jian, Lan K.; Russell, Christopher T.; Strangeway, Robert J.; Luhmann, Janet G.; Leisner, Jared S.; Galvin, Antoinette B.

    2009-08-20

    Using high-resolution magnetic field data from the STEREO mission, we have observed strong narrow-band ion cyclotron waves (ICWs) in the solar wind near 1 AU. The waves propagate nearly parallel to the magnetic field and are below the local proton gyrofrequency in the solar wind frame. Because the twin STEREO spacecraft were far away from any planet, including the Earth, the waves do not have a planetary source. The ICWs often appear when the interplanetary magnetic field is more radial than the nominal Parker spiral. Since the wave frequency in the spacecraft frame is higher than the local proton gyrofrequency, the waves are not locally generated by ion pickup. Observations are consistent with wave generation closer to the Sun and outward transport by the super-Alfvenic solar wind. The waves are intrinsically left-hand polarized in the solar wind frame, but appear to be both left- and right-handed in the spacecraft frame, associated with outward and inward propagation, respectively. The relative amplitudes of the left-handed and right-handed waves support the closer-to-Sun generation scenario.

  3. Are type III radio aurorae directly excited by electrostatic ion cyclotron waves

    SciTech Connect

    McDiarmid, D.R.; Watermann, J.; McNamara, A.G. ); Koehler, J.A.; Sofko, G.J. )

    1989-10-01

    In 1981, a network of three 50-MHz radar transmitters and two receivers were operated in the CW mode on the Canadian prairies. The echoes obtained from coherent ionospheric backscatter were divided into segments of 205 ms such that their FFT spectra yielded frequency resolution of 4.9 Hz. The spectra were subsequently averaged over 10 s. Type III spectra (narrow spectra with sub ion-acoustic Doppler shifts) were observed (often simultaneously) on radar links whose wave vector components perpendicular to the geomagnetic field were almost identical while their components parallel to the field were significantly different. From a statistical analysis of more than 300 type III spectra it is inferred that these are in general unlikely to arise from electrostatic ion cyclotron waves directly excited by an essentially linear process. Doppler shifts around 55 Hz were much more frequently observed than around 30 Hz, the occurrence of type III spectra increased with increasing magnetic aspect angle (deviation of the scatter wave vector from perpendicular to the geomagnetic field), and the mean Doppler shifts of type III spectra simultaneously on different radar links went through a minimum for aspect angles between 4{degree} and 7{degree} (depending on the assumed backscatter height). These three results disagree with theoretical expectations. The spectral width the type III echoes decreased linearly with magnetic aspect by about 2 Hz/deg.

  4. Nanometer fabrication in mercury cadmium telluride by electron cyclotron resonance microwave plasma reactive ion etching

    NASA Astrophysics Data System (ADS)

    Eddy, C. R.; Hoffman, C. A.; Meyer, J. R.; Dobisz, E. A.

    1993-08-01

    It has been recently reported (J.R. Meyer, F.J. Bartoli, C.A. Hoffman, and L.R. Ram-Mohan, Phys. Rev. Lett. 64, 1963 [1990]) that novel electronic and optical effects are anticipated in nanometer scale features of narrow band gap semiconductors such as mercury cadmium telluride (MCT). These efforts could lead to the creation of non-linear optical switches, high efficiency infrared lasers, and unique nanoelectronic devices. This work reports on the first realization of MCT nanostructures through the application of e-beam lithography and reactive ion etching with an electron cyclotron resonance (ECR) microwave plasma source. It is shown that the low energy ions produced by an ECR system can etch MCT with good selectivity over an e-beam resist mask and with high resolution. Using these fabrication methods, 40 70 nm features with aspect ratios of 3 5∶1 and sidewall angles greater than 88° have been demonstrated. Qualitative investigations of some of the etch mechanisms of this technique are made, and results suggest a desorption limited process.

  5. Microgan electron cyclotron resonance ion source in a Van de Graaff accelerator terminal.

    PubMed

    Gaubert, G; Bieth, C; Bougy, W; Brionne, N; Donzel, X; Sineau, A; Vallerand, C; Villari, A C C; Chaves, C; Gamboni, T; Geerts, W; Giorginis, G; Lövestam, G; Mondelaers, W

    2012-02-01

    The Van de Graaff accelerator at IRMM works since many years providing proton, deuteron, and helium beams for nuclear data measurements. The original ion source was of RF type with quartz bottle. This kind of source, as well known, needs regular maintenance for which the accelerator tank must be completely opened. The heavy usage at high currents of the IRMM accelerator necessitated an opening about once every month. In 2010, the full permanent magnet Microgan electron cyclotron resonance (ECR) ion source from PANTECHNIK was installed into a new terminal platform together with a solid state amplifier of 50 W, a dedicated dosing system for 4 gases (with respective gas bottles H(2), D(2), He, and Ar), and a set of dedicated power supplies and electronic devices for the remote tuning of the source. The new system shows a very stable behaviour of the produced beam allowing running the Van de Graaf without maintenance for several months. This contribution will describe the full installed system in details (working at high pressure in the terminal, spark effects, and optic of the extraction), as well as beam results in dc or pulsed mode. PMID:22380187

  6. Development of a pepper-pot device to determine the emittance of an ion beam generated by electron cyclotron resonance ion sources

    SciTech Connect

    Strohmeier, M.; Benitez, J. Y.; Leitner, D.; Lyneis, C. M.; Todd, D. S.; Bantel, M.

    2010-02-15

    This paper describes the recent development and commissioning of a pepper-pot emittance meter at the Lawrence Berkeley National Laboratory (LBNL). It is based on a potassium bromide (KBr) scintillator screen in combination with a charged coupled device camera. Pepper-pot scanners record the full four-dimensional transverse phase space emittances which are particularly interesting for electron cyclotron resonance ion sources. The strengths and limitations of evaluating emittances using optical pepper-pot scanners are described and systematic errors induced by the optical data acquisition system will be presented. Light yield tests of KBr exposed to different ion species and first emittance measurement data using ion beams extracted from the 6.4 GHz LBNL electron cyclotron resonance ion source are presented and discussed.

  7. Development of a pepper-pot device to determine the emittance of an ion beam generated by electron cyclotron resonance ion sources.

    PubMed

    Strohmeier, M; Benitez, J Y; Leitner, D; Lyneis, C M; Todd, D S; Bantel, M

    2010-02-01

    This paper describes the recent development and commissioning of a pepper-pot emittance meter at the Lawrence Berkeley National Laboratory (LBNL). It is based on a potassium bromide (KBr) scintillator screen in combination with a charged coupled device camera. Pepper-pot scanners record the full four-dimensional transverse phase space emittances which are particularly interesting for electron cyclotron resonance ion sources. The strengths and limitations of evaluating emittances using optical pepper-pot scanners are described and systematic errors induced by the optical data acquisition system will be presented. Light yield tests of KBr exposed to different ion species and first emittance measurement data using ion beams extracted from the 6.4 GHz LBNL electron cyclotron resonance ion source are presented and discussed. PMID:20192450

  8. Electrostatic ion cyclotron waves in a plasma with an ion beam and counterstreaming bulk electrons - Waves in the zero-frequency band

    NASA Astrophysics Data System (ADS)

    Singh, N.; Conrad, J. R.; Schunk, R. W.

    1985-12-01

    A common feature of the auroral plasma in the region above field-aligned (parallel) potential drops are electrostatic hydrogen cyclotron (EHC) waves. The present paper has the objective to show that wave excitation in the zero-frequency band can occur when the ion beams and the current-carrying bulk electrons counterstream. The instability mechanism involves the Landau interaction of the slow (negative energy) ion-beam-cyclotron waves with the drifting electrons and also with the target (background) ions. Only the latter resonant interaction between the beam and the target ions was considered by Okuda and Nishikawa (1984). In this study, it is shown that an electron drift makes an additional unstable contribution to the waves in the zero-frequency band, including those discussed by Okuda and Nishikawa.

  9. Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applicationsa)

    NASA Astrophysics Data System (ADS)

    Sortais, P.; Lamy, T.; Médard, J.; Angot, J.; Latrasse, L.; Thuillier, T.

    2010-02-01

    In order to drastically reduce the power consumption of a microwave ion source, we have studied some specific discharge cavity geometries in order to reduce the operating point below 1 W of microwave power (at 2.45 GHz). We show that it is possible to drive an electron cyclotron resonance ion source with a transmitter technology similar to those used for cellular phones. By the reduction in the size and of the required microwave power, we have developed a new type of ultralow cost ion sources. This microwave discharge system (called COMIC, for COmpact MIcrowave and Coaxial) can be used as a source of light, plasma or ions. We will show geometries of conductive cavities where it is possible, in a 20 mm diameter chamber, to reduce the ignition of the plasma below 100 mW and define typical operating points around 5 W. Inside a simple vacuum chamber it is easy to place the source and its extraction system anywhere and fully under vacuum. In that case, current densities from 0.1 to 10 mA/cm2 (Ar, extraction 4 mm, 1 mAe, 20 kV) have been observed. Preliminary measurements and calculations show the possibility, with a two electrodes system, to extract beams within a low emittance. The first application for these ion sources is the ion injection for charge breeding, surface analyzing system and surface treatment. For this purpose, a very small extraction hole is used (typically 3/10 mm for a 3 μA extracted current with 2 W of HF power). Mass spectrum and emittance measurements will be presented. In these conditions, values down to 1 π mm mrad at 15 kV (1σ) are observed, thus very close to the ones currently observed for a surface ionization source. A major interest of this approach is the possibility to connect together several COMIC devices. We will introduce some new on-going developments such as sources for high voltage implantation platforms, fully quartz radioactive ion source at ISOLDE or large plasma generators for plasma immersion, broad or ribbon beams

  10. Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applications

    SciTech Connect

    Sortais, P.; Lamy, T.; Medard, J.; Angot, J.; Latrasse, L.; Thuillier, T.

    2010-02-15

    In order to drastically reduce the power consumption of a microwave ion source, we have studied some specific discharge cavity geometries in order to reduce the operating point below 1 W of microwave power (at 2.45 GHz). We show that it is possible to drive an electron cyclotron resonance ion source with a transmitter technology similar to those used for cellular phones. By the reduction in the size and of the required microwave power, we have developed a new type of ultralow cost ion sources. This microwave discharge system (called COMIC, for COmpact MIcrowave and Coaxial) can be used as a source of light, plasma or ions. We will show geometries of conductive cavities where it is possible, in a 20 mm diameter chamber, to reduce the ignition of the plasma below 100 mW and define typical operating points around 5 W. Inside a simple vacuum chamber it is easy to place the source and its extraction system anywhere and fully under vacuum. In that case, current densities from 0.1 to 10 mA/cm{sup 2} (Ar, extraction 4 mm, 1 mAe, 20 kV) have been observed. Preliminary measurements and calculations show the possibility, with a two electrodes system, to extract beams within a low emittance. The first application for these ion sources is the ion injection for charge breeding, surface analyzing system and surface treatment. For this purpose, a very small extraction hole is used (typically 3/10 mm for a 3 {mu}A extracted current with 2 W of HF power). Mass spectrum and emittance measurements will be presented. In these conditions, values down to 1 {pi} mm mrad at 15 kV (1{sigma}) are observed, thus very close to the ones currently observed for a surface ionization source. A major interest of this approach is the possibility to connect together several COMIC devices. We will introduce some new on-going developments such as sources for high voltage implantation platforms, fully quartz radioactive ion source at ISOLDE or large plasma generators for plasma immersion, broad or ribbon

  11. Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

    PubMed

    Yorita, Tetsuhiko; Hatanaka, Kichiji; Fukuda, Mitsuhiro; Kibayashi, Mitsuru; Morinobu, Shunpei; Okamura, Hiroyuki; Tamii, Atsushi

    2010-02-01

    An 18 GHz superconducting electron cyclotron resonance ion source has been installed as a subject of the azimuthally varying field cyclotron upgrade project (K. Hatanaka et al., in Proceedings of the 17th International Conference on Cyclotrons and Their Applications, Tokyo, Japan, 18-22 October 2004, pp. 115-117), in order to increase beam currents and to extend the variety of ions. The production development of several ions has been performed since 2006 and some of them have already been used for user experiments [T. Yorita et al., Rev. Sci. Instrum. 79, 02A311 (2008)]. Further optimizations for each component such as the material of plasma electrode, material, and shape of bias probe and mirror field have been continued and more intense ion beams have been obtained for O, N, and Ar. For the purpose of obtaining highly charged Xe with several microamperes, the optimization of position and shape of plasma electrode and bias disk has also been done and highly charged Xe(32+) beam has been obtained successfully. PMID:20192353

  12. Effect of high energy electrons on H- production and destruction in a high current DC negative ion source for cyclotron

    NASA Astrophysics Data System (ADS)

    Onai, M.; Etoh, H.; Aoki, Y.; Shibata, T.; Mattei, S.; Fujita, S.; Hatayama, A.; Lettry, J.

    2016-02-01

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H- production. The modelling results reasonably explains the dependence of the H- extraction current on the arc-discharge power in the experiments.

  13. Generation of electromagnetic ion cyclotron waves in the near-Earth magnetotail during dipolarization: Two-dimensional global hybrid simulation

    NASA Astrophysics Data System (ADS)

    Guo, Zhifang; Wu, Mingyu; Du, Aimin

    2016-04-01

    We employ two-dimensional global hybrid simulations to study the generation, propagation, and polarization of electromagnetic ion cyclotron (EMIC) waves in the near-Earth magnetotail (around x = - 10 R E ) during dipolarization. In our simulation, EMIC waves with left-hand polarized signals originate in the low-latitude magnetotail as a result of the ion temperature anisotropy which is due to ion heating by Alfvén waves. Subsequently, EMIC waves can propagate along the ambient magnetic field toward high-latitudes. Our work provides one possible mechanism for the generation of EMIC waves observed in the near-Earth magnetotail.

  14. Pulsed-gas glow discharge for ultrahigh mass resolution measurements with Fourier transform ion cyclotron resonance mass spectrometry

    SciTech Connect

    Watson, C.H.; Eyler, J.R.; Barshick, C.M.; Wronka, J.; Laukien, F.H.

    1996-02-01

    A new pulsed-gas glow discharge (GD) source has been developed for use with an external ion source Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. With pulsed argon gas introduction into the GD source, the gas load and pressure in the mass analyzer region were greatly reduced; this resulted in improved mass resolution. Mass resolution of greater than 145000 (fwhm) has been achieved for Cu{sup +} ions from a brass sample, the highest reported for any type of GD mass spectrometer. The pulsed-gas GD source promises analytical usefulness for ultrahigh resolution measurements in GD mass spectrometry. 16 refs., 3 figs.

  15. Role of Parallel and Oblique Ion-Cyclotron Waves in Heating Ions in an Inhomogeneous Expanding Solar Wind Plasma

    NASA Astrophysics Data System (ADS)

    Ofman, L.; Ozak, N. O.; Vinas, A. F.

    2014-12-01

    In-situ observations of fast solar wind streams at distances of 0.29 AU and beyond by Helios and recently by MESSENGER, and at ~1 AU by STEREO, ACE, and Wind spacecraft provide direct evidence for the presence of turbulent Alfvén wave spectrum and of left-hand polarized ion-cyclotron waves as well as He++ - proton drift in the solar wind plasma. The waves and the super-Alfvénic drift can produce temperature anisotropies by resonant absorption and perpendicular heating of the ions. Measurements indicate that proton velocity distributions are generally non-Maxwellian with evidence for beams, while remote sensing observations of coronal holes have shown that heavy ions are hotter than protons with a temperature anisotropy greater than one (Ti,perp> Ti,||). In addition to the anisotropy, it is expected that the solar wind will be inhomogeneous on decreasing scales approaching the Sun. Here we use a 2.5 D hybrid code and extend previous work to study the heating of solar wind ions (H+, He+) in an inhomogeneous plasma background. We explore the effects of an initial ion drift and of a turbulent wave spectrum on the perpendicular ion heating and cooling and on the spectrum of the magnetic fluctuations in the inhomogeneous background solar wind. Using the 2D hybrid model we find that inhomogeneities in the plasma generate significant power of oblique waves in the solar wind plasma, in addition to enhanced heating compared to the homogenous solar wind case. We find that the cooling effect due to the solar wind expansion is only significant when sub-Alfvénic drifts are explored. On the other hand, the cooling is not significant in the presence of a super-Alfvénic drift, and it is even less significant when we include an inhomogeneous background density. We are able to reproduce the ion temperature anisotropy seen in observations and previous models and find that small-scale inhomogeneities in the inner heliosphere can have a significant impact on resonant wave ion

  16. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited)

    SciTech Connect

    Vondrasek, R.; Levand, A.; Pardo, R.; Savard, G.; Scott, R.

    2012-02-15

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi {sup 252}Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci {sup 252}Cf source to produce radioactive beams with intensities up to 10{sup 6} ions/s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for {sup 23}Na{sup 8+}, 15.6% for {sup 84}Kr{sup 17+}, and 13.7% for {sup 85}Rb{sup 19+} with typical breeding times of 10 ms/charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for {sup 143}Cs{sup 27+} and 14.7% for {sup 143}Ba{sup 27+}. The project has been commissioned with a radioactive beam of {sup 143}Ba{sup 27+} accelerated to 6.1 MeV/u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.

  17. A new 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) for the heavy ion accelerator facility ATLAS

    SciTech Connect

    Schlapp, M.; Pardo, R.C.; Vondrasek, R.C.; Billquist, P.J.; Szczech, J.

    1997-11-01

    A 14 GHz Electron-Cyclotron-Resonance Ion Source (ECRIS) has been designed and built at Argonne National Laboratory. The source is a modification of the AECR at Berkeley and incorporates the latest results from ECR developments to produce intense beams of highly charged ions, including an improved magnetic confinement of the plasma electrons with an axial mirror ratio of 3.5. The aluminum plasma chamber and extraction electrode as well as a biased disk on axis at the microwave injection side donates additional electrons to the plasma, making use of the large secondary electron yield from aluminum oxide. The source is capable of ECR plasma heating using two different frequencies simultaneously to increase the electron energy gain for the production of high charge states. The main design goal is to produce several e{mu}A of at least {sup 238}U{sup 35+} in order to accelerate the beam to coulomb-barrier energies without further stripping. First charge state distributions for gaseous elements have been measured and 210 e{mu}A {sup 16}O{sup 7+} has been achieved. A normalized 90% emittance from 0.1 to 0.2 {pi} mm{sm_bullet}mrad for krypton and oxygen beam has been found.

  18. Current density distributions and sputter marks in electron cyclotron resonance ion sources

    SciTech Connect

    Panitzsch, Lauri; Peleikis, Thies; Boettcher, Stephan; Stalder, Michael; Wimmer-Schweingruber, Robert F.

    2013-01-15

    Most electron cyclotron resonance ion sources use hexapolar magnetic fields for the radial confinement of the plasma. The geometry of this magnetic structure is then-induced by charged particles-mapped onto the inner side of the plasma electrode via sputtering and deposition. The resulting structures usually show two different patterns: a sharp triangular one in the central region which in some cases is even sputtered deep into the material (referred to as thin groove or sharp structure), and a blurred but still triangular-like one in the surroundings (referred to as broad halo). Therefore, both patterns seem to have different sources. To investigate their origins we replaced the standard plasma electrode by a custom-built plasma electrode acting as a planar, multi-segment current-detector. For different biased disc voltages, detector positions, and source biases (referred to the detector) we measured the electrical current density distributions in the plane of the plasma electrode. The results show a strong and sharply confined electron population with triangular shape surrounded by less intense and spatially less confined ions. Observed sputter- and deposition marks are related to the analysis of the results. Our measurements suggest that the two different patterns (thin and broad) indeed originate from different particle populations. The thin structures seem to be caused by the hot electron population while the broad marks seem to stem from the medium to highly charged ions. In this paper we present our measurements together with theoretical considerations and substantiate the conclusions drawn above. The validity of these results is also discussed.

  19. On RF heating of inhomogeneous collisional plasma under ion-cyclotron resonance conditions

    SciTech Connect

    Timofeev, A. V.

    2015-11-15

    During ion-cyclotron resonance (ICR) heating of plasma by the magnetic beach method, as well as in some other versions of ICR heating, it is necessary to excite Alfvén oscillations. In this case, it is difficult to avoid the phenomenon of the Alfvén resonance, in which Alfvén oscillations transform into lower hybrid oscillations. The latter efficiently interact with electrons, due to which most of the deposited RF energy is spent on electron (rather than ion) heating. The Alfvén resonance takes place due to plasma inhomogeneity across the external magnetic field. Therefore, it could be expected that variations in the plasma density profile would substantially affect the efficiency of the interaction of RF fields with charged particles. However, the results obtained for different plasma density profiles proved to be nearly the same. In the present work, a plasma is considered the parameters of which correspond to those planned in future ICR plasma heating experiments on the PS-1 facility at the Kurchatov Institute. When analyzing the interaction of RF fields with charged particles, both the collisionless resonance interaction and the interaction caused by Coulomb collisions are taken into account, because, in those experiments, the Coulomb collision frequency will be comparable with the frequency of the heating field. Antennas used for ICR heating excite RF oscillations with a wide spectrum of wavenumbers along the magnetic field. After averaging over the spectrum, the absorbed RF energy calculated with allowance for collisions turns out to be close to that absorbed in collisionless plasma, the energy fraction absorbed by electrons being substantially larger than that absorbed by ions.

  20. Formation of a conical distribution and intense ion heating in the presence of hydrogen cyclotron waves. [in earth ionosphere

    NASA Technical Reports Server (NTRS)

    Okuda, H.; Ashour-Abdalla, M.

    1981-01-01

    In the considered investigation, it is assumed that the field aligned currents are responsible for producing electrostatic harmonic cyclotron waves (EHC). Using a one-dimensional simulation model in which the electron velocity distribution is maintained by a constant injection of the initial distribution, it is shown that, in contrast to earlier initial value simulations, EHC waves grow to a large amplitude, resulting in the formation of an anisotropic ion velocity distribution. Both the heating rate and the anisotropy are in reasonable agreement with the quasi-linear theory, taking into account the cyclotron resonance. The results show that the saturation is due to the combined effects of wave induced diffusion in an electron velocity space and the heating of ions perpendicularly. Both these effects reduce the growth rate.

  1. Dissipative ion-cyclotron oscillitons in a form of solitons with chirp in Earth's low-altitude ionosphere

    SciTech Connect

    Kovaleva, I. Kh.

    2012-10-15

    In this paper, we consider theoretically nonlinear ion-cyclotron gradient-drift dissipative structures (oscillitons) in low ionospheric plasmas. Similar to Nonlinear Optics and Condensed Matter Physics, the Ginzburg-Landau equation for the envelope of electric wave fields is derived, and solutions for oscillitons in the form of solitons with chirp are examined. The whole dissipative structure constitutes a soliton with a moving charge-neutral density hump. Conditions for excitation and properties of the structures are considered.

  2. RF Sources for the ITER Ion Cyclotron Heating and Current Drive System

    SciTech Connect

    Hosea, J.; Brunkhorst, C.; Fredd, E.; Goulding, R. H.; Goulding, R. H.; Greenough, N.; Kung, C.; Rasmussen, D. A.; Swain, D. W.; Wilson, J. R.

    2005-10-04

    The RF source requirements for the ITER ion cyclotron (IC) heating and current drive system are very challenging ? 20 MW CW power into an antenna load with a VSWR of up to 2 over the frequency range of 35-65 MHz. For the two present antenna designs under consideration, 8 sources providing 2.5 MW each are to be employed. For these sources, the outputs of two final power amplifiers (FPAs), using the high power CPI 4CM2500KG tube, are combined with a 180? hybrid combiner to easily meet the ITER IC source requirements ? 2.5 MW is supplied at a VSWR of 2 at ? 70% of the maximum tube power available in class B operation. The cylindrical cavity configuration for the FPAs is quite compact so that the 8 combined sources fit into the space allocated at the ITER site with room to spare. The source configuration is described in detail and its projected operating power curves are presented. Although the CPI tube has been shown to be stable under high power operating conditions on many facilities, a test of the combined FPA source arrangement is in preparation using existing high power 30 MHz amplifiers to assure that this configuration can be made robustly stable for all phases at a VSWR up to 2. The possibility of using 12 sources to feed a suitably modified antenna design is also discussed in the context of providing flexibility for specifying the final IC antenna design.

  3. Ion cyclotron resonance heating systems upgrade toward high power and CW operations in WEST

    NASA Astrophysics Data System (ADS)

    Hillairet, Julien; Mollard, Patrick; Zhao, Yanping; Bernard, Jean-Michel; Song, Yuntao; Argouarch, Arnaud; Berger-By, Gilles; Charabot, Nicolas; Chen, Gen; Chen, Zhaoxi; Colas, Laurent; Delaplanche, Jean-Marc; Dumortier, Pierre; Durodié, Frédéric; Ekedahl, Annika; Fedorczak, Nicolas; Ferlay, Fabien; Goniche, Marc; Hatchressian, Jean-Claude; Helou, Walid; Jacquot, Jonathan; Joffrin, Emmanuel; Litaudon, Xavier; Lombard, Gilles; Maggiora, Riccardo; Magne, Roland; Milanesio, Daniele; Patterlini, Jean-Claude; Prou, Marc; Verger, Jean-Marc; Volpe, Robert; Vulliez, Karl; Wang, Yongsheng; Winkler, Konstantin; Yang, Qingxi; Yuan, Shuai

    2015-12-01

    The design of the WEST (Tungsten-W Environment in Steady-state Tokamak) Ion cyclotron resonance heating antennas is based on a previously tested conjugate-T Resonant Double Loops prototype equipped with internal vacuum matching capacitors. The design and construction of three new WEST ICRH antennas are being carried out in close collaboration with ASIPP, within the framework of the Associated Laboratory in the fusion field between IRFM and ASIPP. The coupling performance to the plasma and the load-tolerance have been improved, while adding Continuous Wave operation capability by introducing water cooling in the entire antenna. On the generator side, the operation class of the high power tetrodes is changed from AB to B in order to allow high power operation (up to 3 MW per antenna) under higher VSWR (up to 2:1). Reliability of the generators is also improved by increasing the cavity breakdown voltage. The control and data acquisition system is also upgraded in order to resolve and react on fast events, such as ELMs. A new optical arc detection system comes in reinforcement of the Vr/Vf and SHAD systems.

  4. Study and design of the ion cyclotron resonance heating system for the stellarator Wendelstein 7-X

    NASA Astrophysics Data System (ADS)

    Ongena, J.; Messiaen, A.; Van Eester, D.; Schweer, B.; Dumortier, P.; Durodie, F.; Kazakov, Ye. O.; Louche, F.; Vervier, M.; Koch, R.; Krivska, A.; Lyssoivan, A.; Van Schoor, M.; Wauters, T.; Borsuk, V.; Neubauer, O.; Schmitz, O.; Offermans, G.; Altenburg, Y.; Baylard, C.; Birus, D.; Bozhenkov, S.; Hartmann, D. A.; Kallmeyer, J. P.; Renard, S.; Wolf, R. C.; Fülöp, T.

    2014-06-01

    The current status of the mechanical and electromagnetic design for the ICRF antenna system for W7-X is presented. Two antenna plugins are discussed: one consisting of a pair of straps with pre-matching to cover the first frequency band, 25-38 MHz, and a second one consisting of two short strap triplets to cover a frequency band around 76 MHz. This paper focusses on the two strap antenna for the lower frequency band. Power coupling of the antenna to a reference plasma profile is studied with the help of the codes TOPICA and Microwave Studio that deliver the scattering matrix needed for the optimization of the geometric parameters of the straps and antenna box. Radiation power spectra for different phasings of the two straps are obtained using the code ANTITER II and different heating scenario are discussed. The potential for heating, fast particle generation, and current drive is discussed. The problem of RF coupling through the plasma edge and of edge power deposition is summarized. Important elements of the complete ion cyclotron resonance heating system are discussed: a resonator circuit with tap feed to limit the maximum voltage in the system, and a decoupler to counterbalance the large mutual coupling between the 2 straps. The mechanical design highlights the challenges encountered with this antenna: adaptation to a large variety of plasma configurations, the limited space within the port to accommodate the necessary matching components and the watercooling needed for long pulse operation.

  5. Simultaneous observations of subauroral electron temperature enhancements and electromagnetic ion cyclotron waves

    NASA Technical Reports Server (NTRS)

    Erlandson, R. E.; Aggson, T. L.; Hogey, W. R.; Slavin, J. A.

    1993-01-01

    Observational results from an investigation of LF (0.5-4.0 Hz) electromagnetic ion cyclotron waves and subauroral electron temperature enhancements recorded from the DE-2 satellite are presented. Four different wave events were analyzed, all recorded at magnetic latitudes from 57-60 deg, magnetic local times from 8-14 hr, and altitudes from 600-900 km. The peak wave amplitudes during the events ranged from 8-70 nT and 5-30 mV/m in the magnetic and electric field, respectively. Te enhancements at the time of the waves were observed in three of four events. A linear relationship between the wave magnetic field spectral density and Te enhancements was found for these events. The Te enhancements were also correlated with an enhanced flux of low energy electrons. During one event (82104) an enhanced flux of electrons were observed at energies up to 50 eV and at nearly all pitch angles, although the flux was largest in the precipitating and upflowing directions. It is suggested that the waves are responsible for heating the low energy electrons which precipitate to the ionosphere and produce the observed Te enhancements. The upflowing electron population appears to be heated at ionospheric altitudes, below the DE-2 satellite.

  6. High yield neutron generator based on a high-current gasdynamic electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Skalyga, V.; Izotov, I.; Golubev, S.; Sidorov, A.; Razin, S.; Strelkov, A.; Tarvainen, O.; Koivisto, H.; Kalvas, T.

    2015-09-01

    In present paper, an approach for high yield compact D-D neutron generator based on a high current gasdynamic electron cyclotron resonance ion source is suggested. Results on dense pulsed deuteron beam production with current up to 500 mA and current density up to 750 mA/cm2 are demonstrated. Neutron yield from D2O and TiD2 targets was measured in case of its bombardment by pulsed 300 mA D+ beam with 45 keV energy. Neutron yield density at target surface of 109 s-1 cm-2 was detected with a system of two 3He proportional counters. Estimations based on obtained experimental results show that neutron yield from a high quality TiD2 target bombarded by D+ beam demonstrated in present work accelerated to 100 keV could reach 6 × 1010 s-1 cm-2. It is discussed that compact neutron generator with such characteristics could be perspective for a number of applications like boron neutron capture therapy, security systems based on neutron scanning, and neutronography.

  7. Inert gas purgebox for Fourier transform ion cyclotron resonance mass spectrometry of air-sensitive solids

    NASA Astrophysics Data System (ADS)

    May, Michael A.; Marshall, Alan G.

    1994-03-01

    A sealed rigid ``purgebox'' makes it possible to load air- and/or moisture-sensitive solids into the solids probe inlet of a Fourier transform ion cyclotron resonance (FT/ICR) mass spectrometer. A pelletized sample is transferred (in a sealed canister) from a commercial drybox to a Lucite(R) purgebox. After the box is purged with inert gas, an attached glove manipulator is used to transfer the sample from the canister to the solids probe of the mass spectrometer. Once sealed inside the inlet, the sample is pre-evacuated and then passed into the high vacuum region of the instrument at ˜10-7 Torr. The purgebox is transparent, portable, and readily assembled/disassembled. Laser desorption FT/ICR mass spectra of the air- and moisture-sensitive solids, NbCl5. NbCl2(C5H5)2, and Zr(CH3)2(C5H5)2 are obtained without significant oxidation. The residual water vapor concentration inside the purgebox was measured as 100±20 ppm after a 90-min purge with dry nitrogen gas. High-resolution laser desorption/ionization mass spectrometry of air-sensitive solids becomes feasible with the present purgebox interface. With minor modification of the purgebox geometry, the present method could be adapted to any mass spectrometer equipped with a solid sample inlet.

  8. Method for calibrating a Fourier transform ion cyclotron resonance mass spectrometer

    DOEpatents

    Smith, Richard D.; Masselon, Christophe D.; Tolmachev, Aleksey

    2003-08-19

    A method for improving the calibration of a Fourier transform ion cyclotron resonance mass spectrometer wherein the frequency spectrum of a sample has been measured and the frequency (f) and intensity (I) of at least three species having known mass to charge (m/z) ratios and one specie having an unknown (m/z) ratio have been identified. The method uses the known (m/z) ratios, frequencies, and intensities at least three species to calculate coefficients A, B, and C, wherein the mass to charge ratio of a least one of the three species (m/z).sub.i is equal to ##EQU1## wherein f.sub.i is the detected frequency of the specie, G(I.sub.i) is a predetermined function of the intensity of the species, and Q is a predetermined exponent. Using the calculated values for A, B, and C, the mass to charge ratio of the unknown specie (m/z).sub.ii is calculated as the sum of ##EQU2## wherein f.sub.ii is the measured frequency of the unknown specie, and (I.sub.ii) is the measured intensity of the unknown specie.

  9. Understanding ion cyclotron harmonic fast wave heating losses in the scrape off layer of tokamak plasmas

    SciTech Connect

    Bertelli, N; Jaeger, E F; Hosea, J C; Phillips, C K; Berry, L; Bonoli, P T; Gerhardt, S P; Green, D; LeBlanc, B; Perkins, R J; Ryan, P M; Taylor, G; Valeo, E J; Wilso, J R; Wright, J C

    2014-07-01

    Fast waves at harmonics of the ion cyclotron frequency, which have been used successfully on National Spherical Torus Experiment (NSTX), will also play an important role in ITER and are a promising candidate for the Fusion Nuclear Science Facility (FNSF) designs based on spherical torus (ST). Experimental studies of high harmonic fast waves (HHFW) heating on the NSTX have demonstrated that substantial HHFW power loss occurs along the open field lines in the scrape-off layer (SOL), but the mechanism behind the loss is not yet understood. The full wave RF code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain, is applied to specific NSTX discharges in order to predict the effects and possible causes of this power loss. In the studies discussed here, a collisional damping parameter has been implemented in AORSA as a proxy to represent the real, and most likely nonlinear, damping processes. A prediction for the NSTX Upgrade (NSTX-U) experiment, that will begin operation next year, is also presented, indicating a favorable condition for the experiment due to a wider evanescent region in edge density.*Research supported by the U.S. DOE under Contract No. DE-AC02-09CH11466 with Princeton University.

  10. In-situ observations of nonlinear wave particle interaction of electromagnetic ion cyclotron waves

    NASA Astrophysics Data System (ADS)

    Shoji, M.; Miyoshi, Y.; Keika, K.; Katoh, Y.; Angelopoulos, V.; Nakamura, S.; Omura, Y.

    2014-12-01

    Direct measurement method for the electromagnetic wave and space plasma interaction has been suggested by a computer simulation study [Katoh et al., 2013], so-called Wave Particle Interaction Analysis (WPIA). We perform the WPIA for rising tone electromagnetic ion cyclotron (EMIC) waves (so-called EMIC triggered emissions), of which generation mechanism is essentially the same as the chorus emissions. THEMIS observation data (EFI, FGM, and ESA) are used for the WPIA. In the WPIA, we calculate (1) the inner product of the wave electric field and the velocity of the energetic protons: Wint, (2) the inner product of the wave magnetic field and the velocity of the energetic protons: WBint, and (3) the phase angle ζ between the wave magnetic field and the perpendicular velocity of the energetic protons. The values of (1) and (2) indicate the existence of the resonant currents inducing the nonlinear wave growth and the frequency change, respectively. We find the negative Wint and positive WBint at the nonlinear growing phase of the triggered emission as predicted in the theory [e.g. Omura and Nunn, 2011, Shoji and Omura, 2013]. In histogram of (3), we show the existence of the electromagnetic proton holes in the phase space generating the resonant currents. We also perform a hybrid simulation and evaluate WPIA method for EMIC waves. The simulation results show good agreement with the in-situ THEMIS observations.

  11. High-Throughput Metabolic Profiling of Soybean Leaves by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    PubMed

    Yilmaz, Ali; Rudolph, Heather L; Hurst, Jerod J; Wood, Troy D

    2016-01-19

    As a relatively recent research field, plant metabolomics has gained increasing interest in the past few years and has been applied to answer biological questions through large-scale qualitative and quantitative analyses of the plant metabolome. The combination of sensitivity and selectivity offered by mass spectrometry (MS) for measurement of many metabolites in a single shot makes it an indispensable platform in metabolomics. In this regard, Fourier-transform ion cyclotron resonance (FTICR) has the unique advantage of delivering high mass resolving power and mass accuracy simultaneously, making it ideal for the study of complex mixtures such as plant extracts. Here we optimize soybean leaf extraction methods compatible with high-throughput reproducible MS-based metabolomics. In addition, matrix-assisted laser desorption ionization (MALDI) and direct LDI of soybean leaves are compared for metabolite profiling. The extraction method combined with electrospray (ESI)-FTICR is supported by the significant reduction of chlorophyll and its related metabolites as the growing season moves from midsummer to the autumn harvest day. To our knowledge for the first time, the use of ESI-FTICR MS and MALDI-FTICR MS is described in a complementary manner with the aim of metabolic profiling of plant leaves that have been collected at different time points during the growing season. PMID:26651857

  12. Theoretical and numerical modelling of chaotic electrostatic ion cyclotron (EIC) oscillations by Jerk equation

    SciTech Connect

    Wharton, A. M. Kumar Shaw, Pankaj; Janaki, M. S.; Sekar Iyengar, A. N.

    2014-02-15

    In the last few years, third order explicit autonomous differential equations, known as jerk equations, have generated great interest as they show features of regular and chaotic motion. In this paper, we have modelled chaotic electrostatic ion cyclotron oscillations using a third order nonlinear ordinary differential equation (ODE) and investigated its nonlinear dynamical properties. The nonlinear ODE has been derived for a plasma system from a two fluid model in the presence of a source term, under the influence of an external magnetic field, which is perpendicular to the direction of the wave vector. It is seen that the equation does not require an external forcing term to obtain chaotic behaviour. The stability of the solutions of the equation has been investigated analytically as well as numerically, and the bifurcation diagram obtained shows a number of interesting phenomena for various regimes of parameters. The coexisting attractors as well as their corresponding basins are shown and the phase space portraits at different conditions are obtained numerically and shown here. The results obtained here are in agreement with preliminary experiments conducted for a similar configuration of a plasma system.

  13. Ion cyclotron resonance heating systems upgrade toward high power and CW operations in WEST

    SciTech Connect

    Hillairet, Julien Mollard, Patrick; Bernard, Jean-Michel; Argouarch, Arnaud; Berger-By, Gilles; Charabot, Nicolas; Colas, Laurent; Delaplanche, Jean-Marc; Ekedahl, Annika; Fedorczak, Nicolas; Ferlay, Fabien; Goniche, Marc; Hatchressian, Jean-Claude; Helou, Walid; Jacquot, Jonathan; Joffrin, Emmanuel; Litaudon, Xavier; Lombard, Gilles; Magne, Roland; Patterlini, Jean-Claude; and others

    2015-12-10

    The design of the WEST (Tungsten-W Environment in Steady-state Tokamak) Ion cyclotron resonance heating antennas is based on a previously tested conjugate-T Resonant Double Loops prototype equipped with internal vacuum matching capacitors. The design and construction of three new WEST ICRH antennas are being carried out in close collaboration with ASIPP, within the framework of the Associated Laboratory in the fusion field between IRFM and ASIPP. The coupling performance to the plasma and the load-tolerance have been improved, while adding Continuous Wave operation capability by introducing water cooling in the entire antenna. On the generator side, the operation class of the high power tetrodes is changed from AB to B in order to allow high power operation (up to 3 MW per antenna) under higher VSWR (up to 2:1). Reliability of the generators is also improved by increasing the cavity breakdown voltage. The control and data acquisition system is also upgraded in order to resolve and react on fast events, such as ELMs. A new optical arc detection system comes in reinforcement of the V{sub r}/V{sub f} and SHAD systems.

  14. High yield neutron generator based on a high-current gasdynamic electron cyclotron resonance ion source

    SciTech Connect

    Skalyga, V.; Sidorov, A.; Izotov, I.; Golubev, S.; Razin, S.; Strelkov, A.; Tarvainen, O.; Koivisto, H.; Kalvas, T.

    2015-09-07

    In present paper, an approach for high yield compact D-D neutron generator based on a high current gasdynamic electron cyclotron resonance ion source is suggested. Results on dense pulsed deuteron beam production with current up to 500 mA and current density up to 750 mA/cm{sup 2} are demonstrated. Neutron yield from D{sub 2}O and TiD{sub 2} targets was measured in case of its bombardment by pulsed 300 mA D{sup +} beam with 45 keV energy. Neutron yield density at target surface of 10{sup 9} s{sup −1} cm{sup −2} was detected with a system of two {sup 3}He proportional counters. Estimations based on obtained experimental results show that neutron yield from a high quality TiD{sub 2} target bombarded by D{sup +} beam demonstrated in present work accelerated to 100 keV could reach 6 × 10{sup 10} s{sup −1} cm{sup −2}. It is discussed that compact neutron generator with such characteristics could be perspective for a number of applications like boron neutron capture therapy, security systems based on neutron scanning, and neutronography.

  15. Study and design of the ion cyclotron resonance heating system for the stellarator Wendelstein 7-X

    SciTech Connect

    Ongena, J.; Messiaen, A.; Van Eester, D.; Schweer, B.; Dumortier, P.; Durodie, F.; Kazakov, Ye. O.; Louche, F.; Vervier, M.; Koch, R.; Krivska, A.; Lyssoivan, A.; Van Schoor, M.; Wauters, T.; Borsuk, V.; Neubauer, O.; Schmitz, O.; Altenburg, Y.; Baylard, C.; and others

    2014-06-15

    The current status of the mechanical and electromagnetic design for the ICRF antenna system for W7-X is presented. Two antenna plugins are discussed: one consisting of a pair of straps with pre-matching to cover the first frequency band, 25–38 MHz, and a second one consisting of two short strap triplets to cover a frequency band around 76 MHz. This paper focusses on the two strap antenna for the lower frequency band. Power coupling of the antenna to a reference plasma profile is studied with the help of the codes TOPICA and Microwave Studio that deliver the scattering matrix needed for the optimization of the geometric parameters of the straps and antenna box. Radiation power spectra for different phasings of the two straps are obtained using the code ANTITER II and different heating scenario are discussed. The potential for heating, fast particle generation, and current drive is discussed. The problem of RF coupling through the plasma edge and of edge power deposition is summarized. Important elements of the complete ion cyclotron resonance heating system are discussed: a resonator circuit with tap feed to limit the maximum voltage in the system, and a decoupler to counterbalance the large mutual coupling between the 2 straps. The mechanical design highlights the challenges encountered with this antenna: adaptation to a large variety of plasma configurations, the limited space within the port to accommodate the necessary matching components and the watercooling needed for long pulse operation.

  16. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited).

    PubMed

    Vondrasek, R; Levand, A; Pardo, R; Savard, G; Scott, R

    2012-02-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi (252)Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci (252)Cf source to produce radioactive beams with intensities up to 10(6) ions∕s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for (23)Na(8+), 15.6% for (84)Kr(17+), and 13.7% for (85)Rb(19+) with typical breeding times of 10 ms∕charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for (143)Cs(27+) and 14.7% for (143)Ba(27+). The project has been commissioned with a radioactive beam of (143)Ba(27+) accelerated to 6.1 MeV∕u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities. PMID:22380254

  17. First operation and effect of a new tandem-type ion source based on electron cyclotron resonance

    NASA Astrophysics Data System (ADS)

    Kato, Yushi; Kimura, Daiju; Yano, Keisuke; Kumakura, Sho; Imai, Youta; Nishiokada, Takuya; Nagaya, Tomoki; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu

    2016-02-01

    A new tandem type source has been constructed on the basis of electron cyclotron resonance plasma for producing synthesized ion beams in Osaka University. Magnetic field in the first stage consists of all permanent magnets, i.e., cylindrically comb shaped one, and that of the second stage consists of a pair of mirror coil, a supplemental coil and the octupole magnets. Both stage plasmas can be individually operated, and produced ions in which is energy controlled by large bore extractor also can be transported from the first to the second stage. We investigate the basic operation and effects of the tandem type electron cyclotron resonance ion source (ECRIS). Analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas in dual plasmas operation as well as each single operation. We describe construction and initial experimental results of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source in future.

  18. First operation and effect of a new tandem-type ion source based on electron cyclotron resonance.

    PubMed

    Kato, Yushi; Kimura, Daiju; Yano, Keisuke; Kumakura, Sho; Imai, Youta; Nishiokada, Takuya; Nagaya, Tomoki; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu

    2016-02-01

    A new tandem type source has been constructed on the basis of electron cyclotron resonance plasma for producing synthesized ion beams in Osaka University. Magnetic field in the first stage consists of all permanent magnets, i.e., cylindrically comb shaped one, and that of the second stage consists of a pair of mirror coil, a supplemental coil and the octupole magnets. Both stage plasmas can be individually operated, and produced ions in which is energy controlled by large bore extractor also can be transported from the first to the second stage. We investigate the basic operation and effects of the tandem type electron cyclotron resonance ion source (ECRIS). Analysis of ion beams and investigation of plasma parameters are conducted on produced plasmas in dual plasmas operation as well as each single operation. We describe construction and initial experimental results of the new tandem type ion source based on ECRIS with wide operation window for aiming at producing synthesized ion beams as this new source can be a universal source in future. PMID:26931929

  19. Effects of chorus, hiss and electromagnetic ion cyclotron waves on radiation belt dynamics (Invited)

    NASA Astrophysics Data System (ADS)

    Horne, R. B.

    2013-12-01

    Wave-particle interactions are known to play an important role in the acceleration and loss of radiation belt electrons, and in the heating and loss of ring current ions. The effectiveness of each wave type on radiation belt dynamics depends on the solar wind interaction with the magnetosphere and the properties of the waves which vary considerably with magnetic local time, radial distance and latitude. Furthermore the interaction of the waves with the particles is usually nonlinear. These factors present a major challenge to test and verify the theories. Here we discuss the role of several types of waves, including whistler mode chorus, plasmaspheric hiss, magnetosonic and electromagnetic ion cyclotron waves, in relation to radiation belt and ring current dynamics. We present simulations of the radiation belts using the BAS radiation belt model which includes the effects of chorus, hiss and EMIC waves along with radial diffusion. We show that chorus waves are required to form the peaks in the electron phase space density during storms, and that this occurs inside geostationary orbit. We compare simulations against observations in medium Earth orbit and the new results from Van Allen probes mission that shows conclusive evidence for a local electron acceleration process near L=4.5. We show the relative importance of plasmaspheric hiss and chorus and the location of the plasmapause for radiation belt dynamics near L=4.5 and demonstrate the losses due to EMIC waves that should occur at high energies. Finally we show how improving our basic physical understanding through missions such as Van Allen probes go to improve space weather forecasting in projects such as SPACECAST and have a direct benefit to society.

  20. Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

    PubMed

    Toivanen, V; Küchler, D

    2016-02-01

    The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ion beams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beam extraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ion beams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extracted beams and a way to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work. PMID:26932095

  1. Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    NASA Astrophysics Data System (ADS)

    Toivanen, V.; Küchler, D.

    2016-02-01

    The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ion beams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beam extraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ion beams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extracted beams and a way to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work.

  2. Experimental observation of ion-cyclotron turbulence in the presence of transverse-velocity shear. Ph.D. Thesis

    SciTech Connect

    Amatucci, W.E.

    1994-01-01

    This laboratory investigation documents the influence of transverse, localized, dc electric fields (TLE) on the excitation of ion-cyclotron waves driven by magnetic field-aligned current (FAC) in a Q-machine plasma device. A segmented disk electrode, located on axis at the end of the plasma column, is used to independently control TLE and FAC in the plasma (potassium plasma, n approximately equals 10(exp 9) cm(exp {minus}3), rho(i) approximately equals 0.2 cm, T(e) = T(i) approximately equals 0.2 eV). Ion-cyclotron waves have been characterized in both the weak-TLE and large-FAC regime and the strong-TLE and small-FAC regime. The existence of a new category of oscillation identified as the inhomogeneous energy-density driven (IEDD) instability is verified based on the properties of the waves in the latter regime. In the weak-TLE regime, current-driven electrostatic ion-cyclotron (CDEIC) waves with features in qualitative agreement with previous laboratory results have been observed at sufficiently large FAC. These waves have a frequency spectrum with a single narrow spectral feature located slightly above the ion-cyclotron frequency (omega approximately equals 1.2 Omega(i)). The waves are standing in the radial direction with peak oscillation amplitude located in the center of the FAC channel and are azimuthally symmetric (m = 0). Small magnitude TLE were found to have negligible effect on the characteristics of the waves. In the strong-TLE regime, a decrease in the threshold FAC level is observed. This transition in the instability threshold is accompanied by changes in the frequency spectra, propagation characteristics, and mode amplitude profiles. In the presence of strong-TLE, the ion-cyclotron waves propagate azimuthally in the E x B direction with k(theta) rho(i) = 0.4 and m = 1. The frequency spectrum becomes broadband and spiky, and shifts with the applied TLE strength.

  3. The production of He-3 and heavy ion enrichment in He-3-rich flares by electromagnetic hydrogen cyclotron waves

    NASA Technical Reports Server (NTRS)

    Temerin, M.; Roth, I.

    1992-01-01

    A new model is presented for the production of He-3 and heavy ion enrichments in He-3-rich flares using a direct single-stage mechanism. In analogy with the production of electromagnetic hydrogen cyclotron waves in earth's aurora by electron beams, it is suggested that such waves should exist in the electron acceleration region of impulsive solar flares. Both analytic and test-particle models of the effect of such waves in a nonuniform magnetic field show that these waves can selectively accelerate He-3 and heavy ions to MeV energies in a single-stage process, in contrast to other models which require a two-stage mechanism.

  4. Emittance study of a 28 GHz electron cyclotron resonance ion source for the Rare Isotope Science Project superconducting linear accelerator.

    PubMed

    Park, Bum-Sik; Hong, In-Seok; Jang, Ji-Ho; Jin, Hyunchang; Choi, Sukjin; Kim, Yonghwan

    2016-02-01

    A 28 GHz electron cyclotron resonance (ECR) ion source is being developed for use as an injector for the superconducting linear accelerator of the Rare Isotope Science Project. Beam extraction from the ECR ion source has been simulated using the KOBRA3-INP software. The simulation software can calculate charged particle trajectories in three dimensional complex magnetic field structures, which in this case are formed by the arrangement of five superconducting magnets. In this study, the beam emittance is simulated to understand the effects of plasma potential, mass-to-charge ratio, and spatial distribution. The results of these simulations and their comparison to experimental results are presented in this paper. PMID:26931953

  5. Emittance study of a 28 GHz electron cyclotron resonance ion source for the Rare Isotope Science Project superconducting linear accelerator

    NASA Astrophysics Data System (ADS)

    Park, Bum-Sik; Hong, In-Seok; Jang, Ji-Ho; Jin, Hyunchang; Choi, Sukjin; Kim, Yonghwan

    2016-02-01

    A 28 GHz electron cyclotron resonance (ECR) ion source is being developed for use as an injector for the superconducting linear accelerator of the Rare Isotope Science Project. Beam extraction from the ECR ion source has been simulated using the KOBRA3-INP software. The simulation software can calculate charged particle trajectories in three dimensional complex magnetic field structures, which in this case are formed by the arrangement of five superconducting magnets. In this study, the beam emittance is simulated to understand the effects of plasma potential, mass-to-charge ratio, and spatial distribution. The results of these simulations and their comparison to experimental results are presented in this paper.

  6. Multicharged ion source based on Penning-type discharge with electron cyclotron resonance heating by millimeter waves.

    PubMed

    Vodopyanov, A V; Izotov, I V; Mansfeld, D A; Yushkov, G Yu

    2012-02-01

    We suggest a Penning-type discharge as a trigger discharge for fast development of pulsed electron cyclotron resonance plasma. The Penning-type discharge glows at a low pressure as needed. Gyrotron radiation (75 GHz, 200 kW, 1 ms) was used for plasma heating. Fully striped helium ions were demonstrated, average charge of ions in the plasma was ≈ 2. Experiment and calculations show that high charge states of heavier gases require lower initial pressure and longer development time. Only moderate charge states are achievable in this pulsed scheme. PMID:22380172

  7. Multicharged ion source based on Penning-type discharge with electron cyclotron resonance heating by millimeter waves

    SciTech Connect

    Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A.; Yushkov, G. Yu.

    2012-02-15

    We suggest a Penning-type discharge as a trigger discharge for fast development of pulsed electron cyclotron resonance plasma. The Penning-type discharge glows at a low pressure as needed. Gyrotron radiation (75 GHz, 200 kW, 1 ms) was used for plasma heating. Fully striped helium ions were demonstrated, average charge of ions in the plasma was {approx_equal} 2. Experiment and calculations show that high charge states of heavier gases require lower initial pressure and longer development time. Only moderate charge states are achievable in this pulsed scheme.

  8. Low energy cyclotron for radiocarbon dating

    SciTech Connect

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

  9. Heavy-ion injector based on an electron cyclotron ion source for the superconducting linear accelerator of the Rare Isotope Science Project

    NASA Astrophysics Data System (ADS)

    Hong, In-Seok; Kim, Yong-Hwan; Choi, Bong-Hyuk; Choi, Suk-Jin; Park, Bum-Sik; Jin, Hyun-Chang; Kim, Hye-Jin; Heo, Jeong-Il; Kim, Deok-Min; Jang, Ji-Ho

    2016-02-01

    The injector for the main driver linear accelerator of the Rare Isotope Science Project in Korea, has been developed to allow heavy ions up to uranium to be delivered to the inflight fragmentation system. The critical components of the injector are the superconducting electron cyclotron resonance (ECR) ion sources, the radio frequency quadrupole (RFQ), and matching systems for low and medium energy beams. We have built superconducting magnets for the ECR ion source, and a prototype with one segment of the RFQ structure, with the aim of developing a design that can satisfy our specifications, demonstrate stable operation, and prove results to compare the design simulation.

  10. Heavy-ion injector based on an electron cyclotron ion source for the superconducting linear accelerator of the Rare Isotope Science Project.

    PubMed

    Hong, In-Seok; Kim, Yong-Hwan; Choi, Bong-Hyuk; Choi, Suk-Jin; Park, Bum-Sik; Jin, Hyun-Chang; Kim, Hye-Jin; Heo, Jeong-Il; Kim, Deok-Min; Jang, Ji-Ho

    2016-02-01

    The injector for the main driver linear accelerator of the Rare Isotope Science Project in Korea, has been developed to allow heavy ions up to uranium to be delivered to the inflight fragmentation system. The critical components of the injector are the superconducting electron cyclotron resonance (ECR) ion sources, the radio frequency quadrupole (RFQ), and matching systems for low and medium energy beams. We have built superconducting magnets for the ECR ion source, and a prototype with one segment of the RFQ structure, with the aim of developing a design that can satisfy our specifications, demonstrate stable operation, and prove results to compare the design simulation. PMID:26931946

  11. A new sawtooth control mechanism relying on toroidally propagating ion cyclotron resonance frequency waves: Theory and Joint European Torus tokamak experimental evidence

    SciTech Connect

    Graves, J. P.; Coda, S.; Chapman, I. T.; Lennholm, M.

    2010-05-15

    The sawtooth control mechanism in plasmas employing toroidally propagating ion cyclotron resonance waves is extended. The asymmetrically distributed energetic passing ions are shown to modify the ideal internal kink mode when the position of the minority ion cyclotron resonance resides within a narrow region close to the q=1 surface. An analytical treatment of the internal kink mode in the presence of model distribution function with parallel velocity asymmetry is developed. The fast ion mechanism explains the strong sensitivity of sawteeth to resonance position, and moreover is consistent with dedicated Joint European Torus [F. Romanelli, Nucl. Fusion 49, 104006 (2009)] experiments which controlled sawteeth despite negligible current drive.

  12. Cyclotron Institute Upgrade Project

    SciTech Connect

    Clark, Henry; Yennello, Sherry; Tribble, Robert

    2014-08-26

    The Cyclotron Institute at Texas A&M University has upgraded its accelerator facilities to extend research capabilities with both stable and radioactive beams. The upgrade is divided into three major tasks: (1) re-commission the K-150 (88”) cyclotron, couple it to existing beam lines to provide intense stable beams into the K-500 experimental areas and use it as a driver to produce radioactive beams; (2) develop light ion and heavy ion guides for stopping radioactive ions created with the K-150 beams; and (3) transport 1+ ions from the ion guides into a charge-breeding electron-cyclotron-resonance ion source (CB-ECR) to produce highly-charged radioactive ions for acceleration in the K-500 cyclotron. When completed, the upgraded facility will provide high-quality re-accelerated secondary beams in a unique energy range in the world.

  13. Variation in crossover frequency of EMIC waves in plasmasphere estimated from ion cyclotron whistler waves observed by Van Allen Probe A

    NASA Astrophysics Data System (ADS)

    Matsuda, Shoya; Kasahara, Yoshiya; Kletzing, Craig A.

    2016-01-01

    We report variations in the propagation of the H+ band ion cyclotron whistlers observed by Van Allen Probe A. Ion cyclotron whistlers are one of the EMIC (electromagnetic ion cyclotron) waves generated by mode conversion from lightning whistlers. Crossover frequency is an important frequency for the ion cyclotron whistlers, which is a function of the variations in the local heavy-ion composition. We surveyed waveform data obtained by the Electric and Magnetic Field Instrument and Integrated Science instrument and found that 3461 H+ band ion cyclotron whistlers were observed from 572 km to 5992 km in altitude. The main finding is that the crossover frequencies of the observed events decreased with increasing altitude. These results support the hypothesis that the total heavy-ion density decreases with increasing altitude. Furthermore, in 96% of all observed events, the crossover frequencies exceeded 0.5fH+, which suggests that the EMIC dispersion relation contains a frequency gap of around 0.5fH+.

  14. Ion cyclotron emission from fusion-born ions in large tokamak plasmas: a brief review from JET and TFTR to ITER

    NASA Astrophysics Data System (ADS)

    Dendy, R. O.; McClements, K. G.

    2015-04-01

    Ion cyclotron emission (ICE) was the first collective radiative instability, driven by confined fusion-born ions, observed from deuterium-tritium plasmas in JET and TFTR. ICE comprises strongly suprathermal emission, which has spectral peaks at multiple ion cyclotron harmonic frequencies as evaluated at the outer mid-plane edge of tokamak plasmas. The measured intensity of ICE spectral peaks scaled linearly with measured fusion reactivity in JET. In other large tokamak plasmas, ICE is currently used as an indicator of fast ions physics. The excitation mechanism for ICE is the magnetoacoustic cyclotron instability (MCI); in the case of JET and TFTR, the MCI is driven by a set of centrally born trapped fusion products, lying just inside the trapped-passing boundary in velocity space, whose drift orbits make large radial excursions to the outer mid-plane edge. Diagnostic exploitation of ICE in future experiments therefore rests in part on deep understanding of the MCI, and recent advances in computational plasma physics have led to substantial recent progress, reviewed here. Particle-in-cell simulations of the MCI, with fully kinetic ions and electrons, were reported in 2013, using plasma parameters for JET ICE observations. The hybrid approximation for plasma simulations, where ions are treated as particles and electrons as a neutralising massless fluid, was then applied and reported in 2014. These simulations extend previous studies deep into the nonlinear regime of the MCI, and corroborate predictions by linear analytical theory, thereby strengthening further the link to ICE measurements. ICE is a potential diagnostic for confined alpha-particles in ITER, where measurements of ICE could yield information on energetic ion behaviour supplementing that obtainable from other diagnostics. In addition, it may be possible to use ICE to study fast ion redistribution and loss due to MHD activity in ITER.

  15. Observations of compound sawteeth in ion cyclotron resonant heating plasma using ECE imaging on experimental advanced superconducting tokamak

    NASA Astrophysics Data System (ADS)

    Hussain, Azam; Zhao, Zhenling; Xie, Jinlin; Zhu, Ping; Liu, Wandong; Ti, Ang

    2016-04-01

    The spatial and temporal evolutions of compound sawteeth were directly observed using 2D electron cyclotron emission imaging on experimental advanced superconducting tokamak. The compound sawtooth consists of partial and full collapses. After partial collapse, the hot core survives as only a small amount of heat disperses outwards, whereas in the following full collapse a large amount of heat is released and the hot core dissipates. The presence of two q = 1 surfaces was not observed. Instead, the compound sawtooth occurs mainly at the beginning of an ion cyclotron resonant frequency heating pulse and during the L-H transition phase, which may be related to heat transport suppression caused by a decrease in electron heat diffusivity.

  16. Note: {sup 6}Li III light intensity observation for {sup 6}Li{sup 3+} ion beam operation at Hyper-Electron Cyclotron Resonance ion source

    SciTech Connect

    Muto, Hideshi; Ohshiro, Yukimitsu; Yamaka, Shoichi; Yamaguchi, Hidetoshi; Shimoura, Susumu; Watanabe, Shin-ichi; Oyaizu, Michihiro; Kobayashi, Kiyoshi; Kotaka, Yasuteru; Nishimura, Makoto; Kase, Masayuki; Kubono, Shigeru; Hattori, Toshiyuki

    2014-12-15

    The light intensity of {sup 6}Li III line spectrum at λ = 516.7 nm was observed during {sup 6}Li{sup 3+} beam tuning at the Hyper-Electron Cyclotron Resonance (ECR) ion source. Separation of ion species of the same charge to mass ratio with an electromagnetic mass analyzer is known to be an exceptionally complex process. However, {sup 6}Li III line intensity observation conducted in this study gives new insights into its simplification of this process. The light intensity of {sup 6}Li III line spectrum from the ECR plasma was found to have a strong correlation with the extracted {sup 6}Li{sup 3+} beam intensity from the RIKEN Azimuthal Varying Field cyclotron.

  17. The impact of UVCS/SOHO observations on models of ion-cyclotron resonance heating of the solar corona

    NASA Technical Reports Server (NTRS)

    Cranmer, S. R.; Field, G. B.; Noci, G.; Kohl, J. L.

    1997-01-01

    The compatibility between theoretical models and observations of the temperatures and anisotropic distributions of hydrogen and minor ions in the solar corona is examined. The ultraviolet coronagraph spectrometer (UVCS) instrument onboard SOHO measured hydrogen kinetic temperatures along lines of sight in coronal holes in excess of 3 x 10(exp 6) K and O(+5) ion kinetic temperatures of at least 2 x 10(exp 8) K. Various features of plasma heating by the dissipation of high-frequency ion-cyclotron resonance Alfven waves, which may be the most natural physical mechanism to produce certain plasma conditions, are examined. Preliminary quantitative models of the ion motion in polar coronal holes are presented, and it is shown that such models can be used to predict the spectrum of waves required to reproduce the observations. Indeed, the more ionic species that are observed spectroscopically, the greater the extent in frequency space the wave spectrum can be inferred.

  18. Nonlinear, stationary electrostatic ion cyclotron waves: Exact solutions for solitons, periodic waves, and wedge shaped waveforms

    SciTech Connect

    McKenzie, J. F.; Doyle, T. B.; Rajah, S. S.

    2012-11-15

    The theory of fully nonlinear stationary electrostatic ion cyclotron waves is further developed. The existence of two fundamental constants of motion; namely, momentum flux density parallel to the background magnetic field and energy density, facilitates the reduction of the wave structure equation to a first order differential equation. For subsonic waves propagating sufficiently obliquely to the magnetic field, soliton solutions can be constructed. Importantly, analytic expressions for the amplitude of the soliton show that it increases with decreasing wave Mach number and with increasing obliquity to the magnetic field. In the subsonic, quasi-parallel case, periodic waves exist whose compressive and rarefactive amplitudes are asymmetric about the 'initial' point. A critical 'driver' field exists that gives rise to a soliton-like structure which corresponds to infinite wavelength. If the wave speed is supersonic, periodic waves may also be constructed. The aforementioned asymmetry in the waveform arises from the flow being driven towards the local sonic point in the compressive phase and away from it in the rarefactive phase. As the initial driver field approaches the critical value, the end point of the compressive phase becomes sonic and the waveform develops a wedge shape. This feature and the amplitudes of the compressive and rarefactive portions of the periodic waves are illustrated through new analytic expressions that follow from the equilibrium points of a wave structure equation which includes a driver field. These expressions are illustrated with figures that illuminate the nature of the solitons. The presently described wedge-shaped waveforms also occur in water waves, for similar 'transonic' reasons, when a Coriolis force is included.

  19. Spatially resolved measurements of electron cyclotron resonance ion source beam profile characteristics

    SciTech Connect

    Panitzsch, Lauri; Stalder, Michael; Wimmer-Schweingruber, Robert F.

    2011-03-15

    Simulations predict that the concentric rings and the triangular structures in the profiles of strongly focused ion beams that are found in different experiments should be dominated by ion species with the same or at least similar m/q-ratio. To verify these theoretical predictions we have tuned our ECR ion source to deliver a beam consisting of multiple ion species whose particular m/q-depending focusing ranges from weakly focused to overfocused. We then recorded spatially resolved charge-state distributions of the beam profile at characteristic positions in the plane perpendicular to the beam line. The results validate theoretical predictions and are summarized in this paper. To achieve the required beam profile characteristics we moved the extraction along the beam line to achieve stronger focusing than by only changing the extraction voltage. To fit the regions of interest of the beam profile into the transmission area of the sector magnet, we steered the beam by moving the extraction in the plane perpendicular to the beam axis. The results of both investigations, beam focusing and beam steering by using a 3D-movable extraction, are also reported in this paper. A brief overview of the new beam monitor extensively used during these measurements, the Faraday cup array, is also given.

  20. Sampling of ions at atmospheric pressure: ion transmission and ion energy studied by simulation and experiment

    NASA Astrophysics Data System (ADS)

    Große-Kreul, Simon; Hübner, Simon; Benedikt, Jan; von Keudell, Achim

    2016-04-01

    Mass spectrometry of ions from atmospheric pressure plasmas is a challenging diagnostic method that has been applied to a large variety of cold plasma sources in the past. However, absolute densities can usually not be obtained, moreover, the process of sampling of ions and neutrals from such a plasma inherently influences the measured composition. These issues are studied in this contribution by a combination of experimental and numerical methods. Different numerical domains are sequentially coupled to calculate the ion transmission from the source to the mass analyzer. It is found that the energy of the sampled ions created by a radio-frequency microplasma operated in a He-N2 mixture at atmospheric pressure is of the order of 0.1 eV and that it depends linearly on the ion mass in good agreement with the expectation for seeded particles accelerated in a supersonic expansion. Moreover, the measured ion energy distribution from an afterglow of an atmospheric pressure plasma can be reproduced on basis of the particle trajectories in the sampling system. Eventually, an estimation of the absolute flux of ions to the detector is deduced.

  1. Concurrent in situ ion irradiation transmission electron microscope

    DOE PAGESBeta

    Hattar, K.; Bufford, D. C.; Buller, D. L.

    2014-08-29

    An in situ ion irradiation transmission electron microscope has been developed and is operational at Sandia National Laboratories. This facility permits high spatial resolution, real time observation of electron transparent samples under ion irradiation, implantation, mechanical loading, corrosive environments, and combinations thereof. This includes the simultaneous implantation of low-energy gas ions (0.8–30 keV) during high-energy heavy ion irradiation (0.8–48 MeV). In addition, initial results in polycrystalline gold foils are provided to demonstrate the range of capabilities.

  2. Self-Consistent Model of Magnetospheric Ring Current and Electromagnetic Ion Cyclotron Waves: The 2-7 May 1998 Storm

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Gamayunov, K. V.; Jordanova, V. K.

    2003-01-01

    A complete description of a self-consistent model of magnetospheric ring current interacting with electromagnetic ion cyclotron waves is presented. The model is based on the system of two kinetic equations; one equation describes the ring current ion dynamics, and another equation describes the wave evolution. The effects on ring current ions interacting with electromagnetic ion cyclotron waves and back on waves are considered self-consistently by solving both equations on a global magnetospheric scale under nonsteady state conditions. The developed model is employed to simulate the entire 2-7 May 1998 storm period. First, the trapped number fluxes of the ring current protons are calculated and presented along with comparison with the data measured by the three- dimensional hot plasma instrument Polar/HYDRA. Incorporating in the model the wave-particle interaction leads to much better agreement between the experimental data and the model results. Second, examining of the wave (MLT, L shell) distributions produced by the model during the storm progress reveals an essential intensification of the wave emission about 2 days after the main phase of the storm. This result is well consistent with the earlier ground-based observations. Finally, the theoretical shapes and the occurrence rates of the wave power spectral densities are studied. It is found that about 2 days after the storm s main phase on 4 May, mainly non-Gaussian shapes of power spectral densities are produced.

  3. Magnetic and nonthermal effects on the dispersion properties of ion-cyclotron surface wave in a semi-bounded generalized Lorentzian plasma

    SciTech Connect

    Lee, Myoung-Jae; Jung, Young-Dae

    2015-05-15

    The magnetic field strength and the nonthermal effects on the dispersion properties of ion-cyclotron surface wave propagating along the interface of a semi-bounded Lorentzian plasma and a vacuum are kinetically investigated. The direction of external magnetic field is applied in parallel to the interface. By employing the specular reflection boundary condition, the dispersion relation of the ion-cyclotron surface wave is derived in the long wavelength limit. The result shows that the phase velocity of the ion-cyclotron surface wave decreases with an increase of the strength of magnetic field. It is found that the increase of suprathermal particle population suppresses the phase velocity of the surface wave. In addition, it is found that the wave velocity increases with increasing ion mass in a semi-bounded Lorentzian plasma.

  4. Note: Optimized circuit for excitation and detection with one pair of electrodes for improved Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Chen, T; Beu, S C; Kaiser, N K; Hendrickson, C L

    2014-06-01

    A conventional Fourier transform-Ion Cyclotron Resonance (ICR) detection cell is azimuthally divided into four equal sections. One pair of opposed electrodes is used for ion cyclotron excitation, and the other pair for ion image charge detection. In this work, we demonstrate that an appropriate electrical circuit facilitates excitation and detection on one pair of opposed electrodes. The new scheme can be used to minimize the number of electrically independent ICR cell electrodes and/or improve the electrode geometry for simultaneously increased ICR signal magnitude and optimal post-excitation radius, which results in higher signal-to-noise ratio and decreased space-charge effects. PMID:24985871

  5. Laser-induced fluorescence of Ba+ ions trapped and mass-selected in a Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Li, G Z; Vining, B A; Guan, S; Marshall, A G

    1996-01-01

    We present the design and preliminary results from a Fourier transform ion cyclotron resonance (ICR) mass spectrometer developed for the direct detection of UV/visible laser-induced fluorescence of trapped, mass-selected, gas-phase ions. A 3 T superconducting magnet and an open-ended multi-section cylindrical Penning trap capture and confine ions created by electron impact or laser desorption. Azimuthal quadrupolar excitation in the presence of ion/neutral collisions cools, axializes and mass selects ions as they fill the trap. A pulsed dye laser pumped by an Nd:YAG laser provides electronic energy excitation. A Brewster window and baffles on each side of the vacuum chamber reduce the scattered light from the excitation laser. Laser-induced fluorescence is collected from mirrors and lenses and directed through a quartz window and fiber-optic bundle to a photomultiplier. The ICR and optical events are controlled by a modular ICR data station and GPIB and RS-232 interfaces. An excitation spectrum is demonstrated for atomic Ba+ ions, and should extend to laser-induced fluorescence of virtually any stable positive or negative gas-phase ions of arbitrary molecular weight: molecular or quasimolecular ions, fragment ions, adduct ions, and ions formed from ion/molecule reactions. PMID:8953788

  6. Production of multicharged ions and behavior of microwave modes in an electron cyclotron resonance ion source directly excited in a circular cavity resonator

    SciTech Connect

    Kato, Yushi; Furuki, Hideyuki; Asaji, Toyohisa; Sato, Fuminobu; Iida, Toshiyuki

    2006-03-15

    Electron cyclotron resonance ion sources (ECRIS) have been widely used for production of high-intensity multicharged ion beams. Making good use of microwave modes is proposed for enhancing the efficiency of ECR for production of multicharged ions (TAIKO II). We can assign the peak position of the electric field of the standing waves to the ECR zone in the directly excited cavity resonator, i.e., the vacuum chamber with the fixed and the mobile plates for selecting and tuning the modes. Periodicity of the extracted multicharged ion currents and plasma parameters is observed as the position of the mobile plate moves. We measure the intensity of the electric field in the ECR plasma by using the insulated semidipole probe and the standing waves are observed. The correlation between the production of multicharged ions and the microwave modes is clarified by measuring the electric field and plasma parameters in the circular cavity resonator.

  7. Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets

    SciTech Connect

    Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki

    2012-02-15

    In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

  8. Preparation and in situ Characterization of Surfaces Using Soft-Landing in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    SciTech Connect

    Alvarez, Jormarie; Cooks, Robert G.; Barlow, Stephan E.; Gaspar, Dan J.; Futrell, Jean H.; Laskin, Julia

    2005-06-01

    Mass-selected peptide ions produced by electrospray ionization were deposited onto fluorinated self-assembled monolayer surfaces (FSAM) surfaces by soft-landing using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) specially designed for studying interactions of large ions with surfaces. Analysis of the modified surface was performed in situ by combining 2 keV Cs+ secondary ion mass spectrometry with FT-ICR detection of the sputtered ions (FT-ICR-SIMS). Regardless of the initial charge state of the precursor ion, the SIMS mass spectra included singly-protonated peptide fragment ions and peaks characteristic of the surfaces in all cases. In some experiments multiply-protonated peptide ions and [M+Au]+ ions were also observed upon SIMS analysis of modified surfaces. For comparison with the in situ analysis of the modified surfaces, ex situ analysis of some of the modified surfaces was performed by 25 kV Ga+ time of flight ? secondary ion mass spectrometry (ToF-SIMS). The ex situ analysis demonstrated that a significant number of soft-landed peptide ions remain charged on the surface even when exposed to air for several hours after deposition. Charge retention of soft-landed ions dramatically increases the ion yields obtained during SIMS analysis very sensitive detection of deposited material at less than 1% of monolayer coverage. Accumulation of charged species on the surface undergoes saturation due to Coulomb repulsion between charges at close to 30% coverage. We estimated that close to 1 ng of peptide could be deposited on the spot area of 4 mm2 of the FSAM surface without reaching saturation.

  9. Effect of high energy electrons on H⁻ production and destruction in a high current DC negative ion source for cyclotron.

    PubMed

    Onai, M; Etoh, H; Aoki, Y; Shibata, T; Mattei, S; Fujita, S; Hatayama, A; Lettry, J

    2016-02-01

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H(-) production. The modelling results reasonably explains the dependence of the H(-) extraction current on the arc-discharge power in the experiments. PMID:26932009

  10. Measurements of energetic helium-3 minority distributions during ion cyclotron radio-frequency heating in the Princeton Large Torus

    SciTech Connect

    Hammett, G.W.; Kaita, R.; Wilson, J.R.

    1988-03-01

    Ion cyclotron radio-frequency heating experiments were performed with a /sup 3/He minority ion species in a /sup 4/He majority plasma in the Princeton Large Torus. The energetic /sup 3/He ion ''tail'' was measured directly with a charge exchange neutral analyzer for the first time. Comparisons with bounce-averaged quasi-linear calculations suggest a modestly peaked radi-frequency power deposition profile. The double charge exchange process /sup 3/He/sup + +/ )plus) /sup 4/He/sup 0/ )plus) /sup 3/He/sup 0/ )plus) /sup 4/He/sup + +/ demonstrated in these measurements may be useful as part of an alpha particle diagnostic in a fusion reactor experiment. 18 refs., 4 figs.

  11. Self-Consistent Model of Magnetospheric Electric Field, Ring Current, Plasmasphere, and Electromagnetic Ion Cyclotron Waves: Initial Results

    NASA Technical Reports Server (NTRS)

    Gamayunov, K. V.; Khazanov, G. V.; Liemohn, M. W.; Fok, M.-C.; Ridley, A. J.

    2009-01-01

    Further development of our self-consistent model of interacting ring current (RC) ions and electromagnetic ion cyclotron (EMIC) waves is presented. This model incorporates large scale magnetosphere-ionosphere coupling and treats self-consistently not only EMIC waves and RC ions, but also the magnetospheric electric field, RC, and plasmasphere. Initial simulations indicate that the region beyond geostationary orbit should be included in the simulation of the magnetosphere-ionosphere coupling. Additionally, a self-consistent description, based on first principles, of the ionospheric conductance is required. These initial simulations further show that in order to model the EMIC wave distribution and wave spectral properties accurately, the plasmasphere should also be simulated self-consistently, since its fine structure requires as much care as that of the RC. Finally, an effect of the finite time needed to reestablish a new potential pattern throughout the ionosphere and to communicate between the ionosphere and the equatorial magnetosphere cannot be ignored.

  12. Implementation of an operator intervention system for remote control of the RIKEN 28 GHz superconducting electron cyclotron resonance ion source

    NASA Astrophysics Data System (ADS)

    Uchiyama, A.; Furukawa, K.; Higurashi, Y.; Nakagawa, T.

    2014-02-01

    The control system for the RIKEN 28 GHz superconducting electron cyclotron resonance ion source (28 GHz SC-ECRIS) consists of a distributed control system based on the experimental physics and industrial control system. To maintain the beam quality for the long beam-service time at the radioactive isotope beam factory, beam tuning to prevent subtle changes in the 28 GHz SC-ECRIS conditions is required. Once this is achieved, it should then be possible to check conditions and operate the ion source at any time. We have designed a web-based operational interface to remotely control the ion source, but for access and control from several locations, suitable access security, policies, and methods are required. We thus implemented an operator intervention system that makes it possible to safely access the network externally with the permission of on-site accelerator operators in the control room.

  13. Aging effects on macadamia nut oil studied by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.

    PubMed

    Proschogo, Nicholas W; Albertson, Peter L; Bursle, Johanna; McConchie, Cameron A; Turner, Athol G; Willett, Gary D

    2012-02-29

    High-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry is successfully used in the detailed molecular analysis of aged macadamia nut oils. The results are consistent with peroxide values, the current industry measure for rancidity, and provide detailed molecular information on the oxidative and hydrolytic degeneration of such oils. Mass analysis of macadamia oil samples stored for extended periods at 6 °C revealed that oils obtained by the cold press method are more susceptible to aging than those obtained using modified Soxhlet or accelerated solvent extraction methods. PMID:22268609

  14. Microwave electron cyclotron electron resonance (ECR) ion source with a large, uniformly distributed, axially symmetric, ECR plasma volume

    DOEpatents

    Alton, Gerald D.

    1996-01-01

    An electron cyclotron resonance (ECR) ion source includes a primary mirror coil disposed coaxially around a vacuum vessel in which a plasma is induced and introducing a solenoidal ECR-producing field throughout the length of the vacuum vessel. Radial plasma confinement is provided by a multi-cusp, multi-polar permanent magnet array disposed azimuthally around the vessel and within the primary mirror coil. Axial confinement is provided either by multi-cusp permanent magnets at the opposite axial ends of the vessel, or by secondary mirror coils disposed on opposite sides of the primary coil.

  15. Scalings of Alfvén-cyclotron and ion Bernstein instabilities on temperature anisotropy of a ring-like velocity distribution in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Min, Kyungguk; Liu, Kaijun; Gary, S. Peter

    2016-03-01

    A ring-like proton velocity distribution with ∂fp(v⊥)/∂v⊥>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion cyclotron harmonics and quasi-perpendicular propagation and an Alfvén-cyclotron instability at frequencies below the proton cyclotron frequency and quasi-parallel propagation. Recent particle-in-cell simulations have demonstrated that even if the maximum linear growth rate of the latter instability is smaller than the corresponding growth of the former instability, the saturation levels of the fluctuating magnetic fields can be greater for the Alfvén-cyclotron instability than for the ion Bernstein instabilities. In this study, linear dispersion theory and two-dimensional particle-in-cell simulations are used to examine scalings of the linear growth rate and saturation level of the two types of growing modes as functions of the temperature anisotropy T⊥/T|| for a general ring-like proton distribution with a fixed ring speed of 2vA, where vA is the Alfvén speed. For the proton distribution parameters chosen, the maximum linear theory growth rate of the Alfvén-cyclotron waves is smaller than that of the fastest-growing Bernstein mode for the wide range of anisotropies (1≤T⊥/T||≤7) considered here. Yet the corresponding particle-in-cell simulations yield a higher saturation level of the fluctuating magnetic fields for the Alfvén-cyclotron instability than for the Bernstein modes as long as T⊥/T|| ≳ 3. Since fast magnetosonic waves with ion Bernstein instability properties observed in the magnetosphere are often not accompanied by electromagnetic ion cyclotron waves, the results of the present study indicate that the ring-like proton distributions responsible for the excitation of these fast magnetosonic waves should not be very anisotropic.

  16. Scalings of Alfvén-cyclotron and ion Bernstein instabilities on temperature anisotropy of a ring-like velocity distribution in the inner magnetosphere

    DOE PAGESBeta

    Min, Kyungguk; Liu, Kaijun; Gary, S. Peter

    2016-03-18

    Here, a ring-like proton velocity distribution with ∂fp(v⊥)/∂v⊥>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion cyclotron harmonics and quasi-perpendicular propagation and an Alfvén-cyclotron instability at frequencies below the proton cyclotron frequency and quasi-parallel propagation. Recent particle-in-cell simulations have demonstrated that even if the maximum linear growth rate of the latter instability is smaller than the corresponding growth of the former instability, the saturation levels of the fluctuating magnetic fields can be greater for the Alfvén-cyclotron instability than for the ion Bernstein instabilities. In thismore » study, linear dispersion theory and two-dimensional particle-in-cell simulations are used to examine scalings of the linear growth rate and saturation level of the two types of growing modes as functions of the temperature anisotropy T⊥/T|| for a general ring-like proton distribution with a fixed ring speed of 2vA, where vA is the Alfvén speed. For the proton distribution parameters chosen, the maximum linear theory growth rate of the Alfvén-cyclotron waves is smaller than that of the fastest-growing Bernstein mode for the wide range of anisotropies (1≤T⊥/T||≤7) considered here. Yet the corresponding particle-in-cell simulations yield a higher saturation level of the fluctuating magnetic fields for the Alfvén-cyclotron instability than for the Bernstein modes as long as inline image. Since fast magnetosonic waves with ion Bernstein instability properties observed in the magnetosphere are often not accompanied by electromagnetic ion cyclotron waves, the results of the present study indicate that the ring-like proton distributions responsible for the excitation of these fast magnetosonic waves should not be very anisotropic.« less

  17. Production of multicharged radioactive ion beams: New results for the 1+-->n+ method with the MINIMAFIOS and SARA-CAPRICE electron cyclotron resonance ion sources

    NASA Astrophysics Data System (ADS)

    Lamy, T.; Bruandet, J.-F.; Chauvin, N.; Curdy, J.-C.; Fruneau, M.; Geller, R.; Gimond, G.; Sole, P.; Vieux-Rochas, J.-L.; Gaubert, G.; Maunoury, L.; Sortais, P.; Villari, A. C. C.

    1998-02-01

    The backward and forward injection of a 1+ ion beam in a MINIMAFIOS type electron cyclotron resonance ion source (ECRIS) have given good results for the 1+→n+ method. Due to the technological simplicity of the forward injection, additional experiments have been performed with this configuration. Different primary sources (1+) have been used for the injection (2.45 GHz ECRIS, hollow cathode source, simplified 10 GHz NANOGAN type ECRIS), an increase of the performances has already been obtained (Zn, Kr, Ar), and a measurement of the absolute efficiency with the NANOGAN type-MINIMAFIOS association is performed. Due to the high performance of the 10 GHz CAPRICE source used as a highly charged ion injector in the first cyclotron of SARA (Système Accélérateur Rhône-Alpes), it has been tested as a different n+ source for the 1+→n+ method. In this purpose, a low energy spread-low emittance thermoionization Rb ion source has been used as 1+ injector. A standard operation of the SARA-CAPRICE source has been kept with respect to the microwave coupling. The spectra of the Rbn+ ions extracted are compared when using N2 and O2 as support gases. The highest efficiency is obtained for the Rb13+.

  18. Production of multicharged radioactive ion beams: New results for the 1+-->n+ method with the MINIMAFIOS and SARA-CAPRICE electron cyclotron resonance ion sources

    NASA Astrophysics Data System (ADS)

    Lamy, T.; Bruandet, J.-F.; Chauvin, N.; Curdy, J.-C.; Fruneau, M.; Geller, R.; Gimond, G.; Sole, P.; Vieux-Rochas, J.-L.; Gaubert, G.; Maunoury, L.; Sortais, P.; Villari, A. C. C.

    1998-03-01

    The backward and forward injection of a 1+ ion beam in a MINIMAFIOS type electron cyclotron resonance ion source (ECRIS) have given good results for the 1+→n+ method. Due to the technological simplicity of the forward injection, additional experiments have been performed with this configuration. Different primary sources (1+) have been used for the injection (2.45 GHz ECRIS, hollow cathode source, simplified 10 GHz NANOGAN type ECRIS), an increase of the performances has already been obtained (Zn, Kr, Ar), and a measurement of the absolute efficiency with the NANOGAN type-MINIMAFIOS association is performed. Due to the high performance of the 10 GHz CAPRICE source used as a highly charged ion injector in the first cyclotron of SARA (Système Accélérateur Rhône-Alpes), it has been tested as a different n+ source for the 1+→n+ method. In this purpose, a low energy spread-low emittance thermoionization Rb ion source has been used as 1+ injector. A standard operation of the SARA-CAPRICE source has been kept with respect to the microwave coupling. The spectra of the Rbn+ ions extracted are compared when using N2 and O2 as support gases. The highest efficiency is obtained for the Rb13+.

  19. High-power microwave transmission systems for electron-cyclotron-resonance plasma heating

    SciTech Connect

    Vernon, R.J.

    1991-08-01

    This progress report is for the sixth year of a grant from the US Department of Energy for the design, development, and fabrication of ECRH transmission and mode conversion systems to transport microwave power from a gyrotron to a magnetically confined plasma. The design and low-power testing of new and improved components for such systems and development of underlying theory is the focus of this project. Devising and improving component testing and diagnostic techniques is also an important part of this effort. The development of possible designs for sections of gyrotrons themselves, such as tapers or Vlasov-type launchers, in support of the Varian gyrotron development program is also considered when appropriate. We also provide support to other groups working on ECR heating of magnetically confined plasmas such as the groups at General Atomics, the University of Texas at Austin, and Lawrence Livermore National Laboratory. During the last year, we designed and had fabricated a two-dimensional Vlasov antenna system for a 110 GHz TE{sub 15,2} mode gyrotron for possible use at General Atomics. The system included the launcher section, a visor, main reflector, and focusing reflector. Programs to generate the tool-path profiles to cut the General Atomics'' Vlasov components on a milling machine were developed. We have also developed state-of-the art theory and programs for three-dimensional whispering-gallery-mode Vlasov antenna systems. A design for a 110 GHz TE{sub 01}-TE{sub 15,2} mode converter system for cold testing WGM Vlasov antenna systems was developed and is currently being fabricated also.

  20. Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like wall

    SciTech Connect

    Jacquet, P. Monakhov, I.; Arnoux, G.; Brix, M.; Graham, M.; Meigs, A.; Sirinelli, A.; Colas, L.; Czarnecka, A.; Lerche, E.; Van-Eester, D.; Mayoral, M.-L.; Brezinsek, S.; Campergue, A.-L.; Klepper, C. C.; Milanesio, D.; and others

    2014-06-15

    In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall materials on the JET Ion Cyclotron Resonance Frequency (ICRF) operation is assessed and some important properties of JET plasmas heated with ICRF are highlighted. A ∼ 20% reduction of the antenna coupling resistance is observed with the ILW as compared with the JET carbon (JET-C) wall. Heat-fluxes on the protecting limiters close the antennas, quantified using Infra-Red thermography (maximum 4.5 MW/m{sup 2} in current drive phasing), are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. The location of the tungsten ICRF specific source could not be identified but some experimental observations indicate that main-chamber W components could be an important impurity source: for example, the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions, and Be evaporation in the main chamber results in a strong reduction of the impurity level. In L-mode plasmas, the ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 15%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating performance; the power is typically deposited at the plasma centre while the radiation is mainly from the outer part of the plasma bulk. Application of ICRF heating in H-mode plasmas has started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core has been observed.

  1. Ion cyclotron resonance frequency heating in JET during initial operations with the ITER-like walla)

    NASA Astrophysics Data System (ADS)

    Jacquet, P.; Bobkov, V.; Colas, L.; Czarnecka, A.; Lerche, E.; Mayoral, M.-L.; Monakhov, I.; Van-Eester, D.; Arnoux, G.; Brezinsek, S.; Brix, M.; Campergue, A.-L.; Devaux, S.; Drewelow, P.; Graham, M.; Klepper, C. C.; Meigs, A.; Milanesio, D.; Mlynar, J.; Pütterich, T.; Sirinelli, A.

    2014-06-01

    In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall materials on the JET Ion Cyclotron Resonance Frequency (ICRF) operation is assessed and some important properties of JET plasmas heated with ICRF are highlighted. A ˜ 20% reduction of the antenna coupling resistance is observed with the ILW as compared with the JET carbon (JET-C) wall. Heat-fluxes on the protecting limiters close the antennas, quantified using Infra-Red thermography (maximum 4.5 MW/m2 in current drive phasing), are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. The location of the tungsten ICRF specific source could not be identified but some experimental observations indicate that main-chamber W components could be an important impurity source: for example, the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions, and Be evaporation in the main chamber results in a strong reduction of the impurity level. In L-mode plasmas, the ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 15%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating performance; the power is typically deposited at the plasma centre while the radiation is mainly from the outer part of the plasma bulk. Application of ICRF heating in H-mode plasmas has started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core has been observed.

  2. Convective instabilities of electromagnetic ion cyclotron waves in the outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Horne, Richard B.; Thorne, Richard M.

    1994-01-01

    The path-integrated linear growth of electromagnetic ion cyclotron waves in the outer (L is greater than or equal to 7) magnetosphere is investigated using a realistic thermal plasma distribution with an additional anisotropic energetic ring current H(+) to provide free energy for instability. The results provide a realistic simulation of the recent Active Magneto- spheric Particle Tracer Explorers (AMPTE) observations. For conditions typical of the dayside magnetosphere, high plasma beta effects reduce the group velocity and significantly increase the spatial growth rates for left-handed polarized instabilities just below the helium gyrofrequency Omega(sub He(+)), and on the guided mode above Omega(sub He(+)) but below the cross over frequency omega(sub cr). Relatively high densities, typical of the afternoon local time sector, favor these low group velocity effects for predominantly field-aligned waves. Lower densities, typical of those found in the early morning local time sector, increase the group velocity but allow strong convective instabilities at high normalized frequencies well above Omega(sub He(+)). These waves are reflected in the magnetosphere and can exist for several equatorial transits without significant damping. They are left-handed polarized only on the first equatorial crossing and become linearly polarized for the remainder of the ray path. Consequently, these waves should be observed with basically linear polarization at all frequencies and all latitudes in the early morning local time sector. Wave growth below Omega(sub He(+)) is severely limited owing to the narrow bandwidth for instability and the small resonant path lengths. In the afternoon sector, where plasma densities can exceed 10(exp 7)/cu m, intense convective amplification is possible both above and below Omega(sub He(+)). Waves below Omega(sub He(+)) are not subject to reflection when the O(+) concentration is small and therefore should be observed with left-handed polarization

  3. Energy spectrum of longitudinal ion losses in the GDT facility under development of Alfvén ion-cyclotron instability

    SciTech Connect

    Anikeev, A. V. Bagryansky, P. A.; Zaitsev, K. V.; Korobeinikova, O. A.; Murakhtin, S. V. Skovorodin, D. I.; Yurov, D. V.

    2015-10-15

    The influence of Alfvén ion cyclotron instability on the longitudinal losses of particles and energy from the GDT gas-dynamic trap was studied experimentally. To record the energy spectrum of ions escaping from the facility along magnetic field lines, a wide-range energy analyzer was attached to the expander. Processing of the experimental data made it possible to determine the time evolution of the ion energy distribution function and showed that the relative increase in the loss power during the development of instability did not exceed 1%. This result confirms the main conclusion of the theoretical model describing the interaction between an Alfvén wave and resonance particles and predicting that this microinstability insignificantly affects the confinement of hot ions in open magnetic traps.

  4. Compact injector with alternating phase focusing-interdigital H-mode linac and superconducting electron cyclotron resonance ion source for heavy ion cancer therapy

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Hattori, Toshiyuki; Matsui, Shinjiro; Tomizawa, Hiromitsu; Yoshida, Toru; Isokawa, Katsushi; Kitagawa, Atsushi; Muramatsu, Masayuki; Yamada, Satoru; Okamura, Masahiro

    2000-02-01

    We have researched a compact medical accelerator with low investment and running cost for the popularization of heavy ion cancer therapy. As the first step, the compact injector system has been investigated for a Heavy Ion Medical Accelerator in Chiba at National Institute of Radiological Sciences. The proposed new injector system consists of a 6 MeV/u interdigital H-mode (IH) linac of 3.1 m long and a 18 GHz superconducting electron cyclotron resonance (ECR) (SC-ECR) ion source. The IH linac with high power efficiency is appropriate to a medical and industrial injector system. Its beam trajectory was simulated and a prototype has been constructed. The SC-ECR ion source has been designed to realize lightweight and low power consumption and the mirror field distribution was estimated.

  5. Observation of upper drift modes in radio frequency produced magnetized plasmas with frequency above ion cyclotron frequency

    NASA Astrophysics Data System (ADS)

    Ghosh, Abhijit; Saha, S. K.; Chowdhury, S.; Janaki, M. S.

    2015-12-01

    In a RF produced magnetized argon plasma expanding into a larger expansion chamber, electrostatic modes propagating azimuthally in the direction of the electron diamagnetic drift and frequency greater than the ion cyclotron frequency are observed. In the radial direction, the mode amplitude peaks at a location where the radial density gradient is maximum. The modes are detected at axial locations up to 16 cm away from the entrance aperture. For fixed values of the neutral pressure and magnetic field, the mode frequency is found to be independent of the location at which it is measured. The modes exhibit drift wave characteristics revealing a radial structure with the azimuthal mode number m = 1 at the lower radial locations (r ˜ 3.0 cm) while the m = 2 mode is located in the outer region. Theoretical modeling using a local dispersion relation based on the fluid equations predicts destabilization of the modes with frequency greater than the ion-cyclotron frequency by electron-neutral collisions and exhibiting other drift wave features.

  6. Effect of the minority concentration on ion cyclotron resonance heating in presence of the ITER-like wall in JET

    SciTech Connect

    Van Eester, D.; Lerche, E.; Crombé, K.; Jachmich, S.; Bobkov, V.; Maggi, C.; Neu, R.; Pütterich, T.; Czarnecka, A.; Coenen, J. W.; and others

    2014-02-12

    The most recent JET campaign has focused on characterizing operation with the 'ITER-like' wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority fundamental cyclotron heating in a deuterium plasma was chosen as the reference wave heating scheme in the ion cyclotron domain of frequencies. The present paper discusses the plasma behavior as a function of the minority concentration X[H] in L-mode with up to 4MW of RF power. It was found that the tungsten concentration decreases by a factor of 4 when the minority concentration is increased from X[H] ≈ 5% to X[H] % 20% and that it remains at a similar level when X[H] is further increased to 30%; a monotonic decrease in Beryllium emission is simultaneously observed. The radiated power drops by a factor of 2 and reaches a minimum at X[H] ≈ 20%. It is discussed that poor single pass absorption at too high minority concentrations ultimately tailors the avoidance of the RF induced impurity influx. The edge density being different for different minority concentrations, it is argued that the impact ICRH has on the fate of heavy ions is not only a result of core (wave and transport) physics but also of edge dynamics and fueling.

  7. Observation of upper drift modes in radio frequency produced magnetized plasmas with frequency above ion cyclotron frequency

    SciTech Connect

    Ghosh, Abhijit; Saha, S. K.; Chowdhury, S.; Janaki, M. S.

    2015-12-15

    In a RF produced magnetized argon plasma expanding into a larger expansion chamber, electrostatic modes propagating azimuthally in the direction of the electron diamagnetic drift and frequency greater than the ion cyclotron frequency are observed. In the radial direction, the mode amplitude peaks at a location where the radial density gradient is maximum. The modes are detected at axial locations up to 16 cm away from the entrance aperture. For fixed values of the neutral pressure and magnetic field, the mode frequency is found to be independent of the location at which it is measured. The modes exhibit drift wave characteristics revealing a radial structure with the azimuthal mode number m = 1 at the lower radial locations (r ∼ 3.0 cm) while the m = 2 mode is located in the outer region. Theoretical modeling using a local dispersion relation based on the fluid equations predicts destabilization of the modes with frequency greater than the ion-cyclotron frequency by electron-neutral collisions and exhibiting other drift wave features.

  8. Spectroscopic Constraints on Models of Ion-Cyclotron Resonance Heating in the Polar Solar Corona and Fast Solar Wind

    NASA Astrophysics Data System (ADS)

    Cranmer, S. R.; Field, G. B.; Kohl, J. L.

    1998-12-01

    We present preliminary results from a theoretical model of the heating of minor ions in the fast solar wind. We examine the compatibility between these models and spectroscopic determinations of velocity distribution functions from the UVCS and SUMER instruments aboard SOHO. By examining the dependence of line shapes (which probe the perpendicular velocity distribution) on ion charge and mass, detailed information can be extracted about the preferential heating and the Coulomb collisional coupling. The primary momentum and energy deposition mechanism we investigate is the dissipation of high-frequency (ion-cyclotron resonant) Alfven waves, which can accelerate and heat ions differently depending on their charge and mass. Minor ions which do not appreciably damp the resonant wave amplitudes can be used to constrain the slope of the fluctuation spectrum. SUMER measurements of several ions at heliocentric heights between 1.02 and 1.07 solar radii allow the ``base'' spectrum to be analyzed, and UVCS O VI line widths measured between 1.5 and 3.5 solar radii provide information about the radial evolution of the spectrum. This work is supported by the National Aeronautics and Space Administration under grant NAG5-3192 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the ESA PRODEX program (Swiss contribution).

  9. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

    PubMed

    Toivanen, V; Bellodi, G; Dimov, V; Küchler, D; Lombardi, A M; Maintrot, M

    2016-02-01

    Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented. PMID:26932084

  10. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    NASA Astrophysics Data System (ADS)

    Toivanen, V.; Bellodi, G.; Dimov, V.; Küchler, D.; Lombardi, A. M.; Maintrot, M.

    2016-02-01

    Linac3 is the first accelerator in the heavy ion injector chain of the Large Hadron Collider (LHC), providing multiply charged heavy ion beams for the CERN experimental program. The ion beams are produced with GTS-LHC, a 14.5 GHz electron cyclotron resonance ion source, operated in afterglow mode. Improvement of the GTS-LHC beam formation and beam transport along Linac3 is part of the upgrade program of the injector chain in preparation for the future high luminosity LHC. A mismatch between the ion beam properties in the ion source extraction region and the acceptance of the following Low Energy Beam Transport (LEBT) section has been identified as one of the factors limiting the Linac3 performance. The installation of a new focusing element, an einzel lens, into the GTS-LHC extraction region is foreseen as a part of the Linac3 upgrade, as well as a redesign of the first section of the LEBT. Details of the upgrade and results of a beam dynamics study of the extraction region and LEBT modifications will be presented.

  11. Study of toroidal flow generation by ion cyclotron range of frequency minority heating in the Alcator C-Mod plasma

    NASA Astrophysics Data System (ADS)

    Murakami, S.; Itoh, K.; Zheng, L. J.; Van Dam, J. W.; Bonoli, P.; Rice, J. E.; Fiore, C. L.; Gao, C.; Fukuyama, A.

    2016-01-01

    The averaged toroidal flow of energetic minority ions during ICRF (ion cyclotron range of frequencies) heating is investigated in the Alcator C-Mod plasma by applying the GNET code, which can solve the drift kinetic equation with complicated orbits of accelerated energetic particles. It is found that a co-directional toroidal flow of the minority ions is generated in the region outside of the resonance location, and that the toroidal velocity reaches more than 40% of the central ion thermal velocity (Vtor ˜ 300 km/s with PICRF ˜ 2 MW). When we shift the resonance location to the outside of |r /a |˜0.5 , the toroidal flow immediately inside of the resonance location is reduced to 0 or changes to the opposite direction, and the toroidal velocity shear is enhanced at r/a ˜ 0.5. A radial diffusion equation for toroidal flow is solved by assuming a torque profile for the minority ion mean flow, and good agreements with experimental radial toroidal flow profiles are obtained. This suggests that the ICRF driven minority ion flow is related to the experimentally observed toroidal rotation during ICRF heating in the Alcator C-Mod plasma.

  12. Ion cyclotron radio frequency systems and performance on the tandem mirror experiment-upgrade (TMX-U)

    SciTech Connect

    Moore, T.L.; Molvik, A.W.; Cummins, W.F.; Pedrotti, L.R.; Henderson, A.L.; Karsner, P.G.; Scofield, D.W.; Brooksby, C.A.

    1983-12-01

    High power ion cyclotron radio frequency (ICRF) systems are now gaining greater attention than before as prime driver ion heating systems. Lawrence Livermore National Laboratory (LLNL) has installed a 200 kW high frequency (HF) transmitter system on its Tandem Mirror Experiment-Upgrade (TMX-U). This paper describes the system, antenna, controls, and monitoring apparatus. The transmitter operates into a high Q antenna installed in the central cell region of the experiment. It incorporates a dual-port feedback system to automatically adjust the transmitter's output power and allow the maximum consistent with the plasma loading of the antenna. Special techniques have been used to measure, in real-time, the dynamically changing loading values presented by the plasma. From the measurements, the antenna impedance can be optimized for specified plasma density.

  13. Neutron emission spectroscopy results for internal transport barrier and mode conversion ion cyclotron resonance heating experiments at JET

    SciTech Connect

    Giacomelli, L.; Hjalmarsson, A.; Hellesen, C.; Conroy, S.; Sunden, E. Andersson; Ericsson, G.; Johnson, M. Gatu; Sjoestrand, H.; Weiszflog, M.; Kaellne, J.; Tardocchi, M.; Gorini, G.

    2008-10-15

    The effect of ion cyclotron resonance heating (ICRH) on ({sup 3}He)D plasmas at JET was studied with the time of flight optimized rate (TOFOR) spectrometer dedicated to 2.5 MeV dd neutron measurements. In internal transport barrier (ITB) plasma experiments with large {sup 3}He concentrations (X({sup 3}He)>15%) an increase in neutron yield was observed after the ITB disappeared but with the auxiliary neutral beam injection and ICRH power still applied. The analysis of the TOFOR data revealed the formation of a high energy (fast) D population in this regime. The results were compared to other mode conversion experiments with similar X({sup 3}He) but slightly different heating conditions. In this study we report on the high energy neutron tails originating from the fast D ions and their correlation with X({sup 3}He) and discuss the light it can shed on ICRH-plasma power coupling mechanisms.

  14. On the role of electron energy distribution function in double frequency heating of electron cyclotron resonance ion source plasmas

    SciTech Connect

    Schachter, L. Dobrescu, S.; Stiebing, K. E.

    2014-02-15

    Double frequency heating (DFH) is a tool to improve the output of highly charged ions particularly from modern electron cyclotron resonance ion source installations with very high RF-frequencies. In order to gain information on the DFH-mechanism and on the role of the lower injected frequency we have carried out a series of dedicated experiments where we have put emphasis on the creation of a discrete resonance surface also for this lower frequency. Our well-established method of inserting an emissive MD (metal-dielectric) liner into the plasma chamber of the source is used in these experiments as a tool of investigation. In this way, the electron temperature and density for both ECR zones is increased in a controlled manner, allowing conclusions on the role of the change of the electron-energy-distribution function with and without DFH.

  15. First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS.

    PubMed

    Thomae, R; Conradie, J; Delsink, H; Du Plessis, H; Fourie, D; Hitz, D; Klopp, M; Kohler, I; Kuechler, D; Lussi, C; McAlister, R; Ntshangase, S; Sakildien, M

    2012-02-01

    iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS. PMID:22380170

  16. First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABSa)

    NASA Astrophysics Data System (ADS)

    Thomae, R.; Conradie, J.; Delsink, H.; Du Plessis, H.; Fourie, D.; Hitz, D.; Klopp, M.; Kohler, I.; Kuechler, D.; Lussi, C.; McAlister, R.; Ntshangase, S.; Sakildien, M.

    2012-02-01

    iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS.

  17. First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

    SciTech Connect

    Thomae, R.; Conradie, J.; Delsink, H.; Du Plessis, H.; Fourie, D.; Klopp, M.; Kohler, I.; Lussi, C.; McAlister, R.; Ntshangase, S.; Sakildien, M.; Hitz, D.

    2012-02-15

    iThemba Laboratory for Accelerator Based Science (iThemba LABS) is a multi-disciplinary accelerator facility. One of its main activities is the operation of a separated-sector cyclotron with a K-value of 200, which provides beams of various ion species. These beams are used for fundamental nuclear physics research in the intermediate energy region, radioisotope production, and medical physics applications. Due to the requirements of nuclear physics for new ion species and higher energies, the decision was made to install a copy of the so-called Grenoble test source (GTS) at iThemba LABS. In this paper, we will report on the experimental setup and the first results obtained with the GTS2 at iThemba LABS.

  18. Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions.

    PubMed

    Lu, W; Li, J Y; Kang, L; Liu, H P; Li, H; Li, J D; Sun, L T; Ma, X W

    2014-02-01

    The 320 kV platform for multi-discipline research with highly charged ions is a heavy ion beam acceleration instrument developed by Institute of Modern Physics, which is dedicated to basic scientific researches such as plasma, atom, material physics, and astrophysics, etc. The platform has delivered ion beams of 400 species for 36,000 h. The average operation time is around 5000 h/year. With the beams provided by the platform, lots of outstanding progresses were made in various research fields. The ion source of the platform is an all-permanent magnet electron cyclotron resonance ion source, LAPECR2 (Lanzhou All Permanent ECR ion source No. 2). The maximum axial magnetic fields are 1.28 T at injection and 1.07 T at extraction, and the radial magnetic field is up to 1.21 T at the inner wall of the plasma chamber. The ion source is capable to produce low, medium, and high charge state gaseous and metallic ion beams, such as H(+), (40)Ar(8+), (129)Xe(30+), (209)Bi(33+), etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform. PMID:24593526

  19. Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sourcesa)

    NASA Astrophysics Data System (ADS)

    Pierret, C.; Maunoury, L.; Biri, S.; Pacquet, J. Y.; Tuske, O.; Delferriere, O.

    2008-02-01

    The goal of this article is to present simulations on the extraction from an electron cyclotron resonance ion source (ECRIS). The aim of this work is to find out an extraction system, which allows one to reduce the emittances and to increase the current of the extracted ion beam at the focal point of the analyzing dipole. But first, we should locate the correct software which is able to reproduce the specific physics of an ion beam. To perform the simulations, the following softwares have been tested: SIMION 3D, AXCEL, CPO 3D, and especially, for the magnetic field calculation, MATHEMATICA coupled with the RADIA module. Emittance calculations have been done with two types of ECRIS: one with a hexapole and one without a hexapole, and the difference will be discussed.

  20. Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sources.

    PubMed

    Pierret, C; Maunoury, L; Biri, S; Pacquet, J Y; Tuske, O; Delferriere, O

    2008-02-01

    The goal of this article is to present simulations on the extraction from an electron cyclotron resonance ion source (ECRIS). The aim of this work is to find out an extraction system, which allows one to reduce the emittances and to increase the current of the extracted ion beam at the focal point of the analyzing dipole. But first, we should locate the correct software which is able to reproduce the specific physics of an ion beam. To perform the simulations, the following softwares have been tested: SIMION 3D, AXCEL, CPO 3D, and especially, for the magnetic field calculation, MATHEMATICA coupled with the RADIA module. Emittance calculations have been done with two types of ECRIS: one with a hexapole and one without a hexapole, and the difference will be discussed. PMID:18315194