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Sample records for mefisto electron cyclotron

  1. Field structure and electron life times in the MEFISTO electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Bodendorfer, M. [EPFL - Ecole Polytechnique Federale de Lausanne (Switzerland); University of Berne, Institute of Physics, Space Research and Planetary Sciences, Siedlerstrasse 5, 3012 Berne (Switzerland)], E-mail: michael.bodendorfer@space.unibe.ch; Altwegg, K. [University of Berne, Institute of Physics, Space Research and Planetary Sciences, Siedlerstrasse 5, 3012 Berne (Switzerland); Shea, H. [EPFL - Ecole Polytechnique Federale de Lausanne (Switzerland); Wurz, P. [University of Berne, Institute of Physics, Space Research and Planetary Sciences, Siedlerstrasse 5, 3012 Berne (Switzerland)

    2008-03-15

    The complex magnetic field of the permanent magnet electron cyclotron resonance (ECR) ion source MEFISTO located at the University of Berne has been numerically simulated. For the first time the magnetized volume qualified for electron cyclotron resonance at 2.45 GHz and 87.5 mT has been analyzed in highly detailed 3D simulations with unprecedented resolution. New results were obtained from the numerical simulation of 25,211 electron trajectories. The evident characteristic ion sputtering trident of hexapole confined ECR ion sources has been identified with the field and electron trajectory distribution. Furthermore, unexpected long electron trajectory lifetimes were found.

  2. Field structure and electron life times in the MEFISTO electron cyclotron resonance ion source

    Science.gov (United States)

    Bodendorfer, M.; Altwegg, K.; Shea, H.; Wurz, P.

    2008-03-01

    The complex magnetic field of the permanent magnet electron cyclotron resonance (ECR) ion source MEFISTO located at the University of Berne has been numerically simulated. For the first time the magnetized volume qualified for electron cyclotron resonance at 2.45 GHz and 87.5 mT has been analyzed in highly detailed 3D simulations with unprecedented resolution. New results were obtained from the numerical simulation of 25,211 electron trajectories. The evident characteristic ion sputtering trident of hexapole confined ECR ion sources has been identified with the field and electron trajectory distribution. Furthermore, unexpected long electron trajectory lifetimes were found.

  3. Field structure and electron life times in the MEFISTO Electron Cyclotron Resonance Ion Source

    CERN Document Server

    Bodendorfer, Michael; Shea, Herbert; Wurz, Peter

    2008-01-01

    The complex magnetic field of the permanent-magnet electron cyclotron resonance (ECR) ion source MEFISTO located at the University of Bern have been numerically simulated. For the first time the magnetized volume qualified for electron cyclotron resonance at 2.45 GHz and 87.5 mT has been analyzed in highly detailed 3D simulations with unprecedented resolution. New results were obtained from the numerical simulation of 25211 electron trajectories. The evident characteristic ion sputtering trident of hexapole confined ECR sources has been identified with the field and electron trajectory distribution. Furthermore, unexpected long electron trajectory lifetimes were found.

  4. Electron-Cyclotron Waves

    NARCIS (Netherlands)

    Westerhof, E.

    1994-01-01

    The essential elements of the theory of electron cyclotron waves are reviewed, The two main electro-magnetic modes of propagation are identified and their dispersion and absorption properties are discussed. The importance of the use of the relativistic resonance condition is stressed.

  5. Electron Cyclotron Emission Radiometer

    Science.gov (United States)

    Morales, Cristina

    2009-11-01

    There is much interest in studying plasmas that generate hot electrons. The goal of this project is to develop a wide band electron cyclotron radiometer to measure the non-Maxwellian rapid rises in electron temperature. These rapid increases in temperature will then be correlated to instabilities in the plasma. This project explores a type of noncontact temperature measurement. We will attempt to show the feasibility of electron cyclotron emissions to measure the Maryland Centrifugal Experiment's electron plasma temperature. The radiometer has been designed to have 100dB of gain and a sensitivity of 24mV/dB given by its logarithmic amplifier. If successful, this radiometer will be used as a diagnostic tool in later projects such as the proposed experiment studying magnetic reconnection using solar flux loops.

  6. EC-5 fifth international workshop on electron cyclotron emission and electron cyclotron heating

    Energy Technology Data Exchange (ETDEWEB)

    Prater, R.; Lohr, J. [eds.

    1985-12-31

    This report contains papers on the following topics: electron cyclotron emission measurements; electron cyclotron emission theory; electron cyclotron heating; gyrotron development; and ECH systems and waveguide development. These paper have been indexed separately elsewhere. (LSP).

  7. Electron cyclotron heating and current drive

    NARCIS (Netherlands)

    Westerhof, E.

    1996-01-01

    Plasma heating and non-inductive current drive by waves in the electron cyclotron range of frequencies are reviewed. Both theoretical aspects concerning wave properties, heating and current drive mechanisms, as well as the major experimental results are summarized.

  8. Electron cyclotron resonance heating on TEXTOR

    NARCIS (Netherlands)

    Westerhof, E.; Hoekzema, J. A.; Hogeweij, G. M. D.; Jaspers, R. J. E.; Schüller, F. C.; Barth, C. J.; Bongers, W. A.; Donne, A. J. H.; Dumortier, P.; van der Grift, A. F.; van Gorkom, J. C.; Kalupin, D.; Koslowski, H. R.; Kramer-Flecken, A.; Kruijt, O. G.; Cardozo, N. J. L.; Mantica, P.; van der Meiden, H. J.; Merkulov, A.; Messiaen, A.; Oosterbeek, J. W.; Oyevaar, T.; Poelman, A. J.; Polman, R. W.; Prins, P. R.; Scholten, J.; Sterk, A. B.; Tito, C. J.; Udintsev, V.S.; Unterberg, B.; Vervier, M.; van Wassenhove, G.

    2003-01-01

    The 110 GHz and the new 140 GHz gyrotron systems for electron cyclotron resonance heating (ECRH) and ECCD on TEXTOR are described and results of ECRH experiments with the 110 GHz system are reported. Central ECRH on Ohmic plasmas shows the presence of an internal electron transport barrier near q =

  9. Imaging Cyclotron Orbits of Electrons in Graphene.

    Science.gov (United States)

    Bhandari, Sagar; Lee, Gil-Ho; Klales, Anna; Watanabe, Kenji; Taniguchi, Takashi; Heller, Eric; Kim, Philip; Westervelt, Robert M

    2016-03-09

    Electrons in graphene can travel for several microns without scattering at low temperatures, and their motion becomes ballistic, following classical trajectories. When a magnetic field B is applied perpendicular to the plane, electrons follow cyclotron orbits. Magnetic focusing occurs when electrons injected from one narrow contact focus onto a second contact located an integer number of cyclotron diameters away. By tuning the magnetic field B and electron density n in the graphene layer, we observe magnetic focusing peaks. We use a cooled scanning gate microscope to image cyclotron trajectories in graphene at 4.2 K. The tip creates a local change in density that casts a shadow by deflecting electrons flowing nearby; an image of flow can be obtained by measuring the transmission between contacts as the tip is raster scanned across the sample. On the first magnetic focusing peak, we image a cyclotron orbit that extends from one contact to the other. In addition, we study the geometry of orbits deflected into the second point contact by the tip.

  10. Hybrid simulation of electron cyclotron resonance heating

    CERN Document Server

    Ropponen, T; Suominen, P; Koponen, T K; Kalvas, T; Koivisto, H

    2008-01-01

    Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

  11. Hybrid simulation of electron cyclotron resonance heating

    Energy Technology Data Exchange (ETDEWEB)

    Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Suominen, P. [CERN Geneve 23, CH-1211 (Switzerland); Koponen, T.K. [Department of Physics, University of Jyvaeskylae, Nanoscience Center, P.O. Box 35, FI-40014 (Finland); Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

    2008-03-11

    Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.

  12. Tokamak startup with electron cyclotron heating

    Energy Technology Data Exchange (ETDEWEB)

    Holly, D J; Prager, S C; Shepard, D A; Sprott, J C

    1980-04-01

    Experiments are described in which the startup voltage in a tokamak is reduced by approx. 60% by the use of a modest amount of electron cyclotron resonance heating power for preionization. A 50% reduction in volt-second requirement and impurity reflux are also observed.

  13. Stability of the Electron Cyclotron Resonance

    Science.gov (United States)

    Asch, Joachim; Bourget, Olivier; Meresse, Cédric

    2015-12-01

    We consider the magnetic AC Stark effect for the quantum dynamics of a single particle in the plane under the influence of an oscillating homogeneous electric and a constant perpendicular magnetic field. We prove that the electron cyclotron resonance is insensitive to impurity potentials.

  14. A line-of-sight electron cyclotron emission receiver for electron cyclotron resonance heating feedback control of tearing modes

    DEFF Research Database (Denmark)

    Oosterbeek, J.W.; Bürger, A.; Westerhof, E.;

    2008-01-01

    An electron cyclotron emission (ECE) receiver inside the electron cyclotron resonance heating (ECRH) transmission line has been brought into operation. The ECE is extracted by placing a quartz plate acting as a Fabry-Perot interferometer under an angle inside the electron cyclotron wave (ECW) beam...

  15. TFTR Michelson interferometer electron cyclotron emission diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; McCarthy, M.P.

    1985-05-01

    In July 1984, a Fourier transform spectrometer employing a fast-scanning Michelson interferometer began operating on TFTR. This diagnostic system can measure the electron cyclotron emission spectrum 72 times per s with a time resolution of 11 ms and a spectral resolution of 3.6 GHz. The initial operating spectral range is 75--540 GHz, which is adequate for measuring the first three cyclotron harmonics at present TFTR magnetic field levels. The range can be extended easily to 75--1080 GHz in order to accommodate increases in toroidal magnetic field or to study superthermal ECE. The measured spectra are absolutely calibrated using a liquid nitrogen cooled blackbody reference source. The second harmonic feature of each spectrum is used to calculate the absolute electron temperature profile.

  16. Microwave Absorption in Electron Cyclotron Resonance Plasma

    Institute of Scientific and Technical Information of China (English)

    LIU Ming-Hai; HU Xi-Wei; WU Qin-Chong; YU Guo-Yang

    2000-01-01

    The microwave power absorption in electron cyclotron resonance plasma reactor was investigated with a twodimensional hybrid-code. Simulation results indicated that there are two typical power deposition profiles over the entire parameter region: (1) microwave power deposition peaks on the axis and decreases in radial direction,(2) microwave power deposition has its maximum at some radial position, i.e., a hollow distribution. The spatial distribution of electron temperature resembles always to the microwave power absorption profile. The dependence of plasma parameter on the gas pressure is discussed also.

  17. Electron cyclotron emission diagnostics on KSTAR tokamak.

    Science.gov (United States)

    Jeong, S H; Lee, K D; Kogi, Y; Kawahata, K; Nagayama, Y; Mase, A; Kwon, M

    2010-10-01

    A new electron cyclotron emission (ECE) diagnostics system was installed for the Second Korea Superconducting Tokamak Advanced Research (KSTAR) campaign. The new ECE system consists of an ECE collecting optics system, an overmode circular corrugated waveguide system, and 48 channel heterodyne radiometer with the frequency range of 110-162 GHz. During the 2 T operation of the KSTAR tokamak, the electron temperatures as well as its radial profiles at the high field side were measured and sawtooth phenomena were also observed. We also discuss the effect of a window on in situ calibration.

  18. Electron cyclotron emission diagnostics on KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, S. H. [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Daejeon 305-353 (Korea, Republic of); Lee, K. D.; Kwon, M. [National Fusion Research Institute, 113 Gwahangno, Daejeon 305-333 (Korea, Republic of); Kogi, Y. [Fukuoka Institute of Technology, Higashiku, Fukuoka 811-0295 (Japan); Kawahata, K.; Nagayama, Y. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Mase, A. [KASTEC, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2010-10-15

    A new electron cyclotron emission (ECE) diagnostics system was installed for the Second Korea Superconducting Tokamak Advanced Research (KSTAR) campaign. The new ECE system consists of an ECE collecting optics system, an overmode circular corrugated waveguide system, and 48 channel heterodyne radiometer with the frequency range of 110-162 GHz. During the 2 T operation of the KSTAR tokamak, the electron temperatures as well as its radial profiles at the high field side were measured and sawtooth phenomena were also observed. We also discuss the effect of a window on in situ calibration.

  19. Benchmarking of codes for electron cyclotron heating and electron cyclotron current drive under ITER conditions

    NARCIS (Netherlands)

    Prater, R.; Farina, D.; Gribov, Y.; Harvey, R. W.; Ram, A. K.; Lin-Liu, Y. R.; Poli, E.; Smirnov, A. P.; Volpe, F.; Westerhof, E.; Zvonkovo, A.

    2008-01-01

    Optimal design and use of electron cyclotron heating requires that accurate and relatively quick computer codes be available for prediction of wave coupling, propagation, damping and current drive at realistic levels of EC power. To this end, a number of codes have been developed in laboratories wor

  20. Electron Cyclotron Resonance Heating of a High-Density Plasma

    DEFF Research Database (Denmark)

    Hansen, F. Ramskov

    1986-01-01

    Various schemes for electron cyclotron resonance heating of tokamak plasmas with the ratio of electron plasma frequency to electron cyclotron frequency, "»pe/^ce* larger than 1 on axis, are investigated. In particular, a mode conversion scheme is investigated using ordinary waves at the fundamental...

  1. Electron cyclotron resonance heating and current drive

    Energy Technology Data Exchange (ETDEWEB)

    Fidone, I.; Castejon, F.

    1992-07-01

    A brief summary of the theory and experiments on electron- cyclotron heating and current drive is presented. The general relativistic formulation of wave propagation and linear absorption is considered in some detail. The O-mode and the X-mode for normal and oblique propagation are investigated and illustrated by several examples. The experimental verification of the theory in T-10 and D- III-D is briefly discussed. Quasilinear evolution of the momentum distribution and related applications as, for instance, non linear wave, damping and current drive, are also considered for special cases of wave frequencies, polarization and propagation. In the concluding section we present the general formulation of the wave damping and current drive in the absence of electron trapping for arbitrary values of the wave frequency. (Author) 13 refs.

  2. The next generation of electron cyclotron emission imaging diagnostics (invited)

    NARCIS (Netherlands)

    Zhang, P.; Domier, C.W.; Liang, T.; Kong, X.; Tobias, B.; Shen, Z.; N C Luhmann Jr.,; Park, H.; Classen, I.G.J.; van de Pol, M.J.; Donne, A. J. H.; R. Jaspers,

    2008-01-01

    A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T-e profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities

  3. The next generation of electron cyclotron emission imaging diagnostics (invited)

    NARCIS (Netherlands)

    Zhang, P.; Domier, C.W.; Liang, T.; Kong, X.; Tobias, B.; Shen, Z.; N C Luhmann Jr.,; Park, H.; Classen, I.G.J.; van de Pol, M.J.; Donne, A. J. H.; R. Jaspers,

    2008-01-01

    A 128 channel two-dimensional electron cyclotron emission imaging system collects time-resolved 16x8 images of T-e profiles and fluctuations on the TEXTOR tokamak. Electron cyclotron emission imaging (ECEI) is undergoing significant changes which promise to revolutionize and extend its capabilities

  4. Single-electron detection and spectroscopy via relativistic cyclotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Bradley, Rich; De Viveiros Souza Filho, Luiz A.; Doe, Peter J.; Fernandes, Justin L.; Fertl, M.; Finn, Erin C.; Formaggio, Joseph; Furse, Daniel L.; Jones, Anthony M.; Kofron, Jared N.; LaRoque, Benjamin; Leber, Michelle; MCBride, Lisa; Miller, M. L.; Mohanmurthy, Prajwal T.; Monreal, Ben; Oblath, Noah S.; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Rysewyk, Devyn M.; Sternberg, Michael G.; Tedeschi, Jonathan R.; Thummler, Thomas; VanDevender, Brent A.; Woods, N. L.

    2015-04-01

    It has been understood since 1897 that accelerating charges should emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spectrometer. We observe the cyclotron radiation emitted by individual electrons that are produced with mildly-relativistic energies by a gaseous radioactive source and are magnetically trapped. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work is a proof-of-concept for future neutrino mass experiments using this technique.

  5. Electron cyclotron emission diagnostic for ITER.

    Science.gov (United States)

    Rowan, W; Austin, M; Beno, J; Ellis, R; Feder, R; Ouroua, A; Patel, A; Phillips, P

    2010-10-01

    Electron temperature measurements and electron thermal transport inferences will be critical to the nonactive and deuterium phases of ITER operation and will take on added importance during the alpha heating phase. The diagnostic must meet stringent criteria on spatial coverage and spatial resolution during full field operation. During the early phases of operation, it must operate equally well at half field. The key to the diagnostic is the front end design. It consists of a quasioptical antenna and a pair of calibration sources. The radial resolution of the diagnostic is less than 0.06 m. The spatial coverage extends at least from the core to the separatrix with first harmonic O-mode being used for the core and second harmonic X-mode being used for the pedestal. The instrumentation used for the core measurement at full field can be used for detection at half field by changing the detected polarization. Intermediate fields are accessible. The electron cyclotron emission systems require in situ calibration, which is provided by a novel hot calibration source. The critical component for the hot calibration source, the emissive surface, has been successfully tested. A prototype hot calibration source has been designed, making use of extensive thermal and mechanical modeling.

  6. Single electron detection and spectroscopy via relativistic cyclotron radiation

    CERN Document Server

    Asner, D M; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thummler, T; VanDevender, B A; Woods, N L

    2014-01-01

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta sp...

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

    Energy Technology Data Exchange (ETDEWEB)

    Skalyga, V. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina st., Nizhny Novgorod (Russian Federation); Izotov, I.; Mansfeld, D. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O. [Department of Physics, University of Jyväskylä, Jyväskylä (Finland)

    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.

  8. Vertical Electron Cyclotron Emission Diagnostic for TCV Plasmas

    Directory of Open Access Journals (Sweden)

    Goodman T. P.

    2012-09-01

    Full Text Available Electron cyclotron resonance heating (ECRH and electron cyclotron current drive (ECCD are used to heat the plasma, to tailor the current profiles and to achieve different operating regimes of tokamak plasmas. Plasmas with ECRH/ECCD are characterized by non-thermal electrons, which cannot be described by a Maxwellian distribution. Non-thermal electrons are also generated during MHD activity, like sawteeth crashes. Quantifying the non-thermal electron distribution is therefore a key for understanding EC heated fusion plasmas. For this purpose a vertical electron cyclotron emission (V-ECE diagnostic is being installed at TCV. The diagnostic layout, the calibration, the analysis technique for data interpretation, the physics potentials and limitations are discussed.

  9. Electron Cyclotron Maser Emissions from Evolving Fast Electron Beams

    CERN Document Server

    Tang, J F; Chen, L; Zhao, G Q; Tan, C M

    2016-01-01

    Fast electron beams (FEBs) are common products of solar active phenomena. Solar radio bursts are an important diagnostic tool in the understanding of FEBs as well as the solar plasma environment in which they are propagating along solar magnetic fields. In particular, the evolutions of the energy spectrum and velocity distribution of FEBs due to the interaction with the ambient plasma and field when propagating can significantly influence the efficiency and property of their emissions. In this paper, we discuss some possible evolutions of the energy spectrum and velocity distribution of FEBs due to the energy loss processes and the pitch-angle effect caused by the magnetic field inhomogeneity, and analyze the effects of these evolutions on electron cyclotron maser (ECM) emission, which is one of the most important mechanisms of producing solar radio bursts by FEBs. The results show that the growth rates all decrease with the energy loss factor $Q$, but increase with the magnetic mirror ratio $\\sigma$ as well ...

  10. 2D electron cyclotron emission imaging at ASDEX Upgrade (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Classen, I. G. J. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Boom, J. E.; Vries, P. C. de [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Suttrop, W.; Schmid, E.; Garcia-Munoz, M.; Schneider, P. A. [Max Planck Institut fuer Plasmaphysik, 85748 Garching (Germany); Tobias, B.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Donne, A. J. H. [FOM-Institute for Plasma Physics, Rijnhuizen, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Jaspers, R. J. E. [Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Park, H. K. [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Munsat, T. [University of Colorado, Boulder, Colorado 80309 (United States)

    2010-10-15

    The newly installed electron cyclotron emission imaging diagnostic on ASDEX Upgrade provides measurements of the 2D electron temperature dynamics with high spatial and temporal resolution. An overview of the technical and experimental properties of the system is presented. These properties are illustrated by the measurements of the edge localized mode and the reversed shear Alfven eigenmode, showing both the advantage of having a two-dimensional (2D) measurement, as well as some of the limitations of electron cyclotron emission measurements. Furthermore, the application of singular value decomposition as a powerful tool for analyzing and filtering 2D data is presented.

  11. Electron Plasmas Cooled by Cyclotron-Cavity Resonance

    CERN Document Server

    Povilus, A P; Evans, L T; Evetts, N; Fajans, J; Hardy, W N; Hunter, E D; Martens, I; Robicheaux, F; Shanman, S; So, C; Wang, X; Wurtele, J S

    2016-01-01

    We observe that high-Q electromagnetic cavity resonances increase the cyclotron cooling rate of pure electron plasmas held in a Penning-Malmberg trap when the electron cyclotron frequency, controlled by tuning the magnetic field, matches the frequency of standing wave modes in the cavity. For certain modes and trapping configurations, this can increase the cooling rate by factors of ten or more. In this paper, we investigate the variation of the cooling rate and equilibrium plasma temperatures over a wide range of parameters, including the plasma density, plasma position, electron number, and magnetic field.

  12. Fokker-Planck Study of Tokamak Electron Cyclotron Resonance Heating

    Institute of Scientific and Technical Information of China (English)

    SHIBingren; LONGYongxing; DONGJiaqi; LIWenzhong; JIAOYiming; WANGAike

    2002-01-01

    In this study, we add a subroutine for describing the electron cyclotron resonant heating calculation to the Fokker-Planck code. By analyzing the wave-particle resonance condition in tokamak plasma and the fast motion of electrons along magnetic field lines, suitable quasi-linear diffusion coefficients are given.

  13. Electron cyclotron emission diagnostics on the large helical device

    Science.gov (United States)

    Nagayama, Y.; Kawahata, K.; England, A.; Ito, Y.; Bretz, N.; McCarthy, M.; Taylor, G.; Doane, J.; Ikezi, H.; Edlington, T.; Tomas, J.

    1999-01-01

    The electron cyclotron emission (ECE) diagnostic system is installed on the large helical device (LHD). The system includes the following instruments: a heterodyne radiometer, a Michelson spectrometer, and a grating polychromator. A 63.5 mm corrugated waveguide system is fully utilized. Large collection optics and notch filters at the frequency of the LHD electron cyclotron heating (ECH) were developed for this system. In addition to these filters, the rectangular waveguide notch filters, the ECE measurement with the radiometer has been successfully performed during the ECH.

  14. Fluid equations in the presence of electron cyclotron current drive

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Thomas G.; Kruger, Scott E. [Tech-X Corporation, 5621 Arapahoe Avenue, Boulder, Colorado 80303 (United States)

    2012-12-15

    Two-fluid equations, which include the physics imparted by an externally applied radiofrequency source near electron cyclotron resonance, are derived in their extended magnetohydrodynamic forms using the formalism of Hegna and Callen [Phys. Plasmas 16, 112501 (2009)]. The equations are compatible with the closed fluid/drift-kinetic model developed by Ramos [Phys. Plasmas 17, 082502 (2010); 18, 102506 (2011)] for fusion-relevant regimes with low collisionality and slow dynamics, and they facilitate the development of advanced computational models for electron cyclotron current drive-induced suppression of neoclassical tearing modes.

  15. Electron cyclotron heating and current drive in toroidal geometry

    Energy Technology Data Exchange (ETDEWEB)

    Kritz, A.H.

    1991-11-01

    The Principal Investigator has continued to work on problems associated both with the deposition and with the emission of electron cyclotron power in toroidal plasmas. We have investigated the use of electron cyclotron resonance heating for bringing compact tokamaks (BPX) to ignition-like parameters. This requires that we continue to refine the modeling capability of the TORCH code linked with the BALDUR 1 {1/2} D transport code. Using this computational tool, we have examined the dependence of ignition on heating and transport employing both theoretical (multi-mode) and empirically based transport models. The work on current drive focused on the suppression of tearing modes near the q = 2 surface and sawteeth near the q = 1 surface. Electron cyclotron current drive in CIT near the q =2 surface was evaluated for a launch scenario where electron cyclotron power was launched near the equatorial plane. The work on suppression of sawteeth has been oriented toward understanding the suppression that has been observed in a number of tokamaks, in particular, in the WT-3 tokamak in Kyoto. To evaluate the changes in current profile (shear) near the q =1 surface, simulations have been carried out using the linked BALDUR-TORCH code. We consider effects on shear resulting both from wave-induced current as well as from changes in conductivity associated with changes in local temperature. Abstracts and a paper relating to this work is included in Appendix A.

  16. Asymmetric Wave Transmission During Electron-Cyclotron Resonant Heating

    NARCIS (Netherlands)

    Peeters, A.G.; Smits, F. M. A.; Giruzzi, G.; Oomens, A. A. M.; Westerhof, E.

    1995-01-01

    In low density plasmas in the RTP tokamak the single-pass absorption of O-mode waves at the fundamental electron cyclotron resonance is observed to be toroidally asymmetric. The absorption is highest for waves travelling in the direction opposite to the toroidal plasma current. Fokker-Planck

  17. Physics of electron cyclotron current drive on DIII-D

    CERN Document Server

    Petty, C C; Harvey, R W; Kinsey, J E; Lao, L L; Lohr, J; Luce, T C; Makowski, M A; Prater, R

    2002-01-01

    OAK A271 PHYSICS OF ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D. Recent experiments on the DIII-D tokamak have focused on determining the effect of trapped particles on the electron cyclotron current drive (ECCD) efficiency. The measured ECCD efficiency increases as the deposition location is moved towards the inboard midplane or towards smaller minor radius for both co and counter injection. The measured ECCD efficiency also increases with increasing electron density and/or temperature. The experimental ECCD is compared to both the linear theory (Toray-GA) as well as a quasilinear Fokker-Planck model (CQL3D). The experimental ECCD is found to be in better agreement with the more complete Fokker-Planck calculation, especially for cases of high rf power density and/or loop voltage. The narrow width of the measured ECCD profile is consistent with only low levels of radial transport for the current carrying electrons.

  18. Electrostatic electron cyclotron instabilities near the upper hybrid layer due to electron ring distributions

    Science.gov (United States)

    Eliasson, B.; Speirs, D. C.; Daldorff, L. K. S.

    2016-09-01

    A theoretical study is presented of the electrostatic electron cyclotron instability involving Bernstein modes in a magnetized plasma. The presence of a tenuous thermal ring distribution in a Maxwellian plasma decreases the frequency of the upper hybrid branch of the electron Bernstein mode until it merges with the nearest lower branch with a resulting instability. The instability occurs when the upper hybrid frequency is somewhat above the third, fourth, and higher electron cyclotron harmonics, and gives rise to a narrow spectrum of waves around the electron cyclotron harmonic nearest to the upper hybrid frequency. For a tenuous cold ring distribution together with a Maxwellian distribution an instability can take place also near the second electron cyclotron harmonic. Noise-free Vlasov simulations are used to assess the theoretical linear growth-rates and frequency spectra, and to study the nonlinear evolution of the instability. The relevance of the results to laboratory and ionospheric heating experiments is discussed.

  19. Electron Cyclotron Waves Polarization in the TJII Stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Cappa, A.; Martinez-Fernandez, J.; Wagner, D.

    2013-05-01

    This report describes the theoretical calculations related with the electron cyclotron (EC) waves polarization control in the TJII stellarator. Two main aspects will be distinguished: the determination of the vacuum polarization that the wave must exhibit if a given propagation mode in a cold plasma is desired and the calculation of the behavior of the grooved polarizers and other transmission systems used to launch the vacuum wave with the required polarization. (Author) 13 refs.

  20. Summary of EC-17: the 17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating (Deurne, The Netherlands, 7-10 May 2012)

    NARCIS (Netherlands)

    Westerhof, E.; Austin, M. E.; Kubo, S.; Lin-Liu, Y. R.; Plaum, B.

    2013-01-01

    An overview is given of the papers presented at the 17th Joint Workshop on Electron Cyclotron Emission (ECE) and Electron Cyclotron Resonance Heating (ECRH). The meeting covered all aspects of the research field ranging from theory to enabling technologies. From the workshop, advanced control by ele

  1. Electron Cyclotron Emission from Nonthermal Distributions

    Science.gov (United States)

    Harvey, R. W.; Coda, S.; Taylor, G.; Austin, M. E.; Prater, R.

    2005-10-01

    The GENRAY ray tracing code incorporates a solution of the RF energy transport equation (emission and absorption along WKB rays) including the effects of nonthermal electron distribution functions. Distributions are from self-consistent RF solutions of the bounce-averaged Fokker-Planck equation using the CQL3D 2V-1R code. We present computed spectra for two experimental situations: (1) EBW emission from electron distributions in NSTX due to future EBWCD experiments. In this case, the calculated transport of the EBW emission from overdense (omega/pe > omega/ce) NSTX plasma to the plasma edge accounts for the effects of BXO mode conversion whereby EBW waves transform to X-mode, then O-mode near the omega/pe=1 surface; and (2) EC emission in present low density DIII-D ECH experiments. A 27 keV central ECE temperature is calculated, in close agreement with the experimental value, for a plasma with 6.5 keV Thomson scattering temperature. Acknowledgment: USDOE Grants DE-AC03-99ER54463 and DE-FG03-02ER54684, and CRPP-EPFL.

  2. Calibration of electron cyclotron emission radiometer for KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Kogi, Y. [Fukuoka Institute of Technology, Fukuoka 811-0295 (Japan); Jeong, S. H. [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Lee, K. D.; Kwon, M. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Akaki, K.; Mase, A. [KASTEC, Kyushu University, Kasuga 816-8580 (Japan); Kuwahara, D. [Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Yoshinaga, T.; Nagayama, Y.; Kawahata, K. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2010-10-15

    We developed and installed an electron cyclotron emission radiometer for taking measurements of Korea Superconducting Tokamak Advanced Research (KSTAR) plasma. In order to precisely measure the absolute value of electron temperatures, a calibration measurement of the whole radiometer system was performed, which confirmed that the radiometer has an acceptably linear output signal for changes in input temperature. It was also found that the output power level predicted by a theoretical calculation agrees with that obtained by the calibration measurement. We also showed that the system displays acceptable noise-temperature performance around 0.23 eV.

  3. Calibration of electron cyclotron emission radiometer for KSTAR.

    Science.gov (United States)

    Kogi, Y; Jeong, S H; Lee, K D; Akaki, K; Mase, A; Kuwahara, D; Yoshinaga, T; Nagayama, Y; Kwon, M; Kawahata, K

    2010-10-01

    We developed and installed an electron cyclotron emission radiometer for taking measurements of Korea Superconducting Tokamak Advanced Research (KSTAR) plasma. In order to precisely measure the absolute value of electron temperatures, a calibration measurement of the whole radiometer system was performed, which confirmed that the radiometer has an acceptably linear output signal for changes in input temperature. It was also found that the output power level predicted by a theoretical calculation agrees with that obtained by the calibration measurement. We also showed that the system displays acceptable noise-temperature performance around 0.23 eV.

  4. MEFISTO An electric field instrument for BepiColombo/MMO

    Science.gov (United States)

    Blomberg, L. G.; Matsumoto, H.; Bougeret, J.-L.; Kojima, H.; Yagitani, S.; Cumnock, J. A.; Eriksson, A. I.; Marklund, G. T.; Wahlund, J.-E.; Bylander, L.; Åhlén, L.; Holtet, J. A.; Ishisaka, K.; Kallio, E.; Kasaba, Y.; Matsuoka, A.; Moncuquet, M.; Mursula, K.; Omura, Y.; Trotignon, J. G.

    2006-01-01

    MEFISTO, together with the companion instrument WPT, are planning the first-ever in situ measurements of the electric field in the magnetosphere of planet Mercury. The instruments have been selected by JAXA for inclusion in the BepiColombo/MMO payload, as part of the Plasma Wave Investigation coordinated by Kyoto University. The magnetosphere of Mercury was discovered by Mariner 10 in 1974 and will be studied further by Messenger starting in 2011. However, neither spacecraft did or will measure the electric field. Electric fields are crucial in the dynamics of a magnetosphere and for the energy and plasma transport between different regions within the magnetosphere as well as between the magnetosphere and the surrounding regions. The MEFISTO instrument will be capable of measuring electric fields from DC to 3 MHz, and will thus also allow diagnostics of waves at all frequencies of relevance to the Hermean magnetosphere. MEFISTO is a double-probe electric field instrument. The double-probe technique has strong heritage and is well proven on missions such as Viking, Polar, and Cluster. For BepiColombo, a newly developed deployment mechanism is planned which reduces the mass by a factor of about 5 compared to conventional mechanisms for 15 m long booms. We describe the basic characteristics of the instrument and briefly discuss the new developments made to tailor the instrument to flight in Mercury orbit.

  5. Potential applications of an electron cyclotron resonance multicusp plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Stirling, W.L. (Oak Ridge National Laboratory, Oak Ridge, TN (USA))

    1990-05-01

    An electron cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produces large (about 25 cm diam), uniform (to within {plus minus}10%), dense ({gt}10{sup 11} cm{sup {minus}3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7 cm (5 in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Results and potential applications of this new ECR plasma source for plasma processing of thin films are discussed.

  6. Effects of electron-cyclotron instabilities on gyrotron beam quality

    Energy Technology Data Exchange (ETDEWEB)

    Jost, G.; Tran, T.M.; Appert, K. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP); Wuethrich, S. [CRAY Research, PATP/PSE, EPFL, Lausanne (Switzerland)

    1996-02-01

    A two-dimensional PIC code aimed at the investigation of electron-cyclotron beam instabilities in gyrotrons and their effects on the beam quality is presented. The code is based on recently developed techniques for handling charge conservation and open boundaries. It has been implemented on the massively parallel computer CRAY T3D. First results show an electromagnetic backward instability periodically growing and decaying to energy levels close to those obtained from the electrostatic Bernstein wave instability. On the average, the resulting beam degradation is 3 to 4 times larger than that predicted by electrostatic models. (author) 8 figs., 14 refs.

  7. Characteristics of surface sterilization using electron cyclotron resonance plasma

    Science.gov (United States)

    Yonesu, Akira; Hara, Kazufumi; Nishikawa, Tatsuya; Hayashi, Nobuya

    2016-07-01

    The characteristics of surface sterilization using electron cyclotron resonance (ECR) plasma were investigated. High-energy electrons and oxygen radicals were observed in the ECR zone using electric probe and optical emission spectroscopic methods. A biological indicator (BI), Geobacillus stearothermophilus, containing 1 × 106 spores was sterilized in 120 s by exposure to oxygen discharges while maintaining a temperature of approximately 55 °C at the BI installation position. Oxygen radicals and high-energy electrons were found to be the sterilizing species in the ECR region. It was demonstrated that the ECR plasma could be produced in narrow tubes with an inner diameter of 5 mm. Moreover, sterilization tests confirmed that the spores present inside the narrow tube were successfully inactivated by ECR plasma irradiation.

  8. Cavity Control of a Single-Electron Quantum Cyclotron:\\\\Measuring the Electron Magnetic Moment

    CERN Document Server

    Hanneke, D; Gabrielse, G

    2010-01-01

    Measurements with a one-electron quantum cyclotron determine the electron magnetic moment, given by $g/2 = 1.001\\,159\\,652\\,180\\,73\\,(28)\\,[0.28~\\textrm{ppt}]$, and the fine structure constant, $\\alpha^{-1}=137.035\\,999\\,084\\,(51)\\,[0.37~\\textrm{ppb}]$. Brief announcements of these measurements are supplemented here with a more complete description of the one-electron quantum cyclotron and the new measurement methods, a discussion of the cavity control of the radiation field, a summary of the analysis of the measurements, and a fuller discussion of the uncertainties.

  9. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature

    NARCIS (Netherlands)

    Schmuck, S.; Fessey, J.; Gerbaud, T.; Alper, B.; Beurskens, M. N. A.; de la Luna, E.; Sirinelli, A.; Zerbini, M.

    2012-01-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron tempe

  10. One-electron quantum cyclotron (and implications for cold antihydrogen)

    CERN Document Server

    Gabrielse, G; Odom, B; D'Urso, B

    2001-01-01

    Quantum jumps between Fock states of a one-electron oscillator reveal the quantum limit of a cyclotron accelerator. The states live for seconds when spontaneous emission is inhibited by a factor of 140 within a cylindrical Penning trap cavity. Averaged over hours the oscillator is in thermal equilibrium with black-body photons in the cavity. At 80 mK, quantum jumps occur only when resonant microwave photons are introduced into the cavity, opening a route to improved measurements of the magnetic moments of the electron and positron. The temperature demonstrated is about 60 times lower than the 4.2 K temperature at which charged elementary particles were previously stored. Implications for the production of cold antihydrogen are discussed. (21 refs).

  11. Electron cyclotron emission measurements at the stellarator TJ-K

    Energy Technology Data Exchange (ETDEWEB)

    Sichardt, Gabriel; Ramisch, Mirko [Institut fuer Grenzflaechenverfahrenstechnik und Plasmatechnologie, Universitaet Stuttgart (Germany); Koehn, Alf [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    2016-07-01

    Electron temperature (T{sub e}) measurements in the magnetised plasmas of the stellarator TJ-K are currently performed by means of Langmuir probes. The use of these probes is restricted to relatively low temperatures and the measurement of temperature profiles requires the acquisition of the local current-voltage characteristics which limits strongly the sampling rate. As an alternative, T{sub e} can be measured using the electron cyclotron emission (ECE) that is generated by the gyration of electrons in magnetised plasmas. Magnetic field gradients in the plasma lead to a spatial distribution of emission frequencies and thus the measured intensity at a given frequency can be related to its point of origin. The T{sub e} dependence of the intensity then leads to a temperature profile along the line of sight for Maxwellian velocity distributions. A diagnostic system for T{sub e} measurements using ECE is currently being set up at TJ-K. When non-thermal electrons are present the emission spectrum changes dramatically. Therefore, the ECE can also be used to investigate the contribution of fast electrons to previously observed toroidal net currents in TJ-K. Simulations are used to examine the role of electron drift orbits in generating these currents.

  12. Electron cyclotron resonance breakdown studies in a linear plasma system

    Indian Academy of Sciences (India)

    Vipin K Yadav; K Sathyanarayana; D Bora

    2008-03-01

    Electron cyclotron resonance (ECR) plasma breakdown is studied in a small linear cylindrical system with four different gases - hydrogen, helium, argon and nitrogen. Microwave power in the experimental system is delivered by a magnetron at 2.45 ± 0.02 GHz in TE10 mode and launched radially to have extra-ordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the fundamental ECR surface ( = 875.0 G) resides at the geometrical centre of the plasma system. ECR breakdown parameters such as plasma delay time and plasma decay time from plasma density measurements are carried out at the centre using a Langmuir probe. The operating parameters such as working gas pressure (1 × 10-5 -1 × 10-2 mbar) and input microwave power (160{800 W) are varied and the corresponding effect on the breakdown parameters is studied. The experimental results obtained are presented in this paper.

  13. Multicusp type Electron Cyclotron Resonance ion source for plasma processing

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, Hiroshi; Shigueoka, Yoshyuki (Institute of Physical and Chemical Research, Wako, Saitama (Japan)); Ishii, Shigeyuki

    1991-02-01

    A multi-cusp type ECR (electron cyclotron resonance) ion source is built with use of SmCo magnets and 2.45 GHz-TE{sub 11} circular mode microwave. The ion source is operated at pressures from 10{sup -4} to 10{sup -3} Torr with the input microwave power from 100 to 400 W. In hydrogen, the current density of H{sup +} is higher than those of H{sub 2}{sup +} and H{sub 3}{sup +}. The dependence of the fraction of each ion species on the power and pressure is measured and explained by rate equations. The source is operated also in other gases. Mass spectra in He, N{sub 2}, O{sub 2}, Ar and CH{sub 4} are shown together with the pressure and power dependences. Multicharged state of up to 3 has been obtained. (author).

  14. Numerical model of electron cyclotron resonance ion source

    Directory of Open Access Journals (Sweden)

    V. Mironov

    2015-12-01

    Full Text Available Important features of the electron cyclotron resonance ion source (ECRIS operation are accurately reproduced with a numerical code. The code uses the particle-in-cell technique to model the dynamics of ions in ECRIS plasma. It is shown that a gas dynamical ion confinement mechanism is sufficient to provide the ion production rates in ECRIS close to the experimentally observed values. Extracted ion currents are calculated and compared to the experiment for a few sources. Changes in the simulated extracted ion currents are obtained with varying the gas flow into the source chamber and the microwave power. Empirical scaling laws for ECRIS design are studied and the underlying physical effects are discussed.

  15. Alternative optical concept for electron cyclotron emission imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J. X., E-mail: jsliu9@berkeley.edu [Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); Milbourne, T. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23185 (United States); Bitter, M.; Delgado-Aparicio, L.; Dominguez, A.; Efthimion, P. C.; Hill, K. W.; Kramer, G. J.; Kung, C.; Pablant, N. A.; Tobias, B. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Kubota, S. [Department of Physics, University of California Los Angeles, Los Angeles, California 90095 (United States); Kasparek, W. [Department of Electrical Engineering, University of Stuttgart, Stuttgart (Germany); Lu, J. [Department of Physics, Chongqing University, Chongqing 400044 (China); Park, H. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of)

    2014-11-15

    The implementation of advanced electron cyclotron emission imaging (ECEI) systems on tokamak experiments has revolutionized the diagnosis of magnetohydrodynamic (MHD) activities and improved our understanding of instabilities, which lead to disruptions. It is therefore desirable to have an ECEI system on the ITER tokamak. However, the large size of optical components in presently used ECEI systems have, up to now, precluded the implementation of an ECEI system on ITER. This paper describes a new optical ECEI concept that employs a single spherical mirror as the only optical component and exploits the astigmatism of such a mirror to produce an image with one-dimensional spatial resolution on the detector. Since this alternative approach would only require a thin slit as the viewing port to the plasma, it would make the implementation of an ECEI system on ITER feasible. The results obtained from proof-of-principle experiments with a 125 GHz microwave system are presented.

  16. Electron-cyclotron heating in the Constance 2 mirror experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mauel, Michael E.

    1982-09-01

    Electron cyclotron heating of a highly-ionized plasma in mirror geometry is investigated. The experimental diagnosis of the electron energy distribution and the comparison of the results of this diagnosis with a two dimensional, time-dependent Fokker-Planck simulation are accomplished in four steps. (1) First, the power balance of the heated and unheated Constance 2 plasma is analyzed experimentally. It is concluded that the heated electrons escape the mirror at a rate dominated by a combination of the influx of cool electrons from outside the mirror and the increased loss rate of the ions. (2) The microwave parameters at the resonance zones are then calculated by cold-plasma ray tracing. High N/sub parallel/ waves are launched and for these waves, strong first-pass absorption is predicted. The absorption strength is qualitatively checked in the experiment by surrounding the plasma with non-reflecting liners. (3) A simplified quasilinear theory including the effect of N/sub parallel/ is developed to model the electrons. An analytic expression is derived for the RF-induced pump-out of the magnetically-confined warm electrons. Results of the Fokker-Planck simulations show the development of the electron energy distribution for several plasma conditions and verify the scaling of the analytic expression for RF-induced diffusion into the loss cone. (4) Sample x-ray and endloss data are presented, and the overall comparison between the simulation and experiment is discussed. The x-ray signals indicate that, for greater RF power, the hot electrondensity increases more rapidly than its temperature. The time history of the endloss data, illustrating RF-enhancement, suggests the predicted scaling for warm-electron pump-out. Finally, a comparison between the measured and predicted energy distribution shows that the bulk, warm and hot components of the heated Constance 2 electrons are indeed reproduced by the simulation.

  17. Conceptual design of CFETR electron cyclotron wave system

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yunying, E-mail: yytang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, Hefei 230031, Anhui (China); University of Science and Technology of China, Jinzhai Road 96, Hefei 230026, Anhui (China); Wang, Xiaojie; Liu, Fukun; Zhang, Liyuan; Wei, Wei; Xu, Handong; Xu, Weiye; Wu, Dajun; Feng, Jianqiang [Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, Hefei 230031, Anhui (China)

    2015-05-15

    Highlights: • The conceptual design of 170 GHz/20 MW electron cyclotron wave system was introduced. • The layout of RF sources was given. • The design and layout of transmission lines were shown and series of microwave components were introduced. • The structure of launcher was described in detail. • By the optic calculation and optimization of RF propagation inside the launcher, the quasi-optical parameters for launcher design were given. And then temperature distribution and thermal-stress of the injection mirror were analyzed. - Abstract: China Fusion Engineering Test Reactor (CFETR) is a test tokamak which is built for magnetically confined fusion plasma experiments. The electron cyclotron (EC) wave system of CFETR is designed to inject 20 MW RF power into the plasma for heating and current drive (H&CD) applications. The EC wave system consists of RF sources, twenty transmission lines (TLs) and one equatorial launcher. RF sources contain twenty gyrotrons with the output power 1 MW. There are series of microwave components distributed along the TL and the percentage of power losses of each TL is about 8.7%. In the equatorial launcher, five RF beams are injected into one focusing mirror and then reflected to the plasma via one injection mirror. The focusing mirror is spherical to focus Gaussian beam and the injection mirror which is flat can steer in the toroidal direction. After optic calculation and optimization, all the quasi-optical parameters for launcher design are given. Combining with the thermal stress analysis, the chosen inner diameter of water channel of injection mirror is 12 mm and the suggested water velocity is 3 m/s.

  18. MEFISTO - an electric field instrument for BepiColombo/MMO

    Science.gov (United States)

    Blomberg, L. G.; Mefisto Team

    MEFISTO, together with the companion instrument PANT, are planning the first-ever in-situ measurements of the electric field in the magnetosphere of planet Mercury. The instruments are proposed to JAXA for inclusion in the BepiColombo/MMO payload, as part of the Plasma Wave Investigation co-ordinated by Kyoto University. The magnetosphere of Mercury was discovered by Mariner 10 in 1974, and will be studied further by Messenger starting in 2009. However, neither spacecraft measures the electric field. Electric fields are crucial in the dynamics of a magnetosphere and for the energy and plasma transport between different regions within the magnetosphere as well as between the magnetosphere and the surrounding regions. The instrument will be capable of measuring electric fields from DC to 3 MHz, and will thus also allow diagnostics of waves at all frequencies of relevance to the Hermean magnetosphere. MEFISTO is a double-probe electric field instrument. The double-probe technique has strong heritage and is well proven on missions such as Viking, Freja, and Cluster. For BepiColombo, a newly developed deployment mechanism is planned which reduces the mass by a factor of about 5 compared to conventional mechanisms. We describe the basic characteristics of the instrument and briefly discuss the new developments made to tailor the instrument to flight in Mercury orbit.

  19. Lower hybrid current drive favoured by electron cyclotron radiofrequency heating

    Energy Technology Data Exchange (ETDEWEB)

    Cesario, R.; Cardinali, A.; Castaldo, C.; Marinucci, M.; Tuccillo, A. A. [Associazione EURATOM/ENEA sulla Fusione, Centro Ricerche Frascati, 00044, Frascati (Italy); Amicucci, L.; Galli, A. [Università di Roma Sapienza, Dipartimento Ingegneria Elettronica, Rome (Italy); Giruzzi, G. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Napoli, F.; Schettini, G. [Università di Roma Tre, Dipartimento Ingegneria Elettronica, Rome (Italy)

    2014-02-12

    The important goal of adding to the bootstrap a fraction of non-inductive plasma current, which would be controlled for obtaining and optimizing steady-state profiles, can be reached by using the Current Drive produced by Lower Hybrid waves (LHCD). FTU (Frascati Tokamak Upgrade) experiments demonstrated, indeed, that LHCD is effective at reactor-graded high plasma density, and the LH spectral broadening is reduced, operating with higher electron temperature in the outer region of plasma column (T{sub e-periphery}). This method was obtained following the guidelines of theoretical predictions indicating that the broadening of launched spectrum produced by parametric instability (PI) should be reduced, and the LHCD effect at high density consequently enabled, under higher (T{sub e-periphery}). In FTU, the temperature increase in the outer plasma region was obtained by operating with reduced particle recycling, lithized walls and deep gas fuelling by means of fast pellet. Heating plasma periphery with electron cyclotron resonant waves (ECRH) will provide a further tool for achieving steady-state operations. New FTU experimental results are presented here, demonstrating that temperature effect at the plasma periphery, affecting LH penetration, occurs in a range of plasma parameters broader than in previous work. New information is also shown on the modelling assessing frequencies and growth rates of the PI coupled modes responsible of spectral broadening. Finally, we present the design of an experiment scheduled on FTU next campaign, where ECRH power is used to slightly increase the electron temperature in the outer plasma region of a high-density discharge aiming at restoring LHCD. Consequent to model results, by operating with a toroidal magnetic field of 6.3 T, useful for locating the electron cyclotron resonant layer at the periphery of the plasma column (r/a∼0.8, f{sub 0}=144 GHz), an increase of T{sub e} in the outer plasma (from 40 eV to 80 eV at r/a∼0.8) is

  20. Electron Cyclotron Current Drive at High Electron Temperature on DIII-D

    Science.gov (United States)

    Petty, C. C.; Austin, M. E.; Harvey, R. W.; Lohr, J.; Luce, T. C.; Makowski, M. A.; Prater, R.

    2007-09-01

    Experiments on DIII-D have measured the electron cyclotron current drive (ECCD) efficiency for co- and counter-injection in low density plasmas with radiation temperatures from electron cyclotron emission (ECE) above 20 keV. The radiation temperature is generally higher than the Thomson scattering temperature, indicating that there is a significant population of non-thermal electrons. The experimental ECCD profile measured with motional Stark effect (MSE) polarimetry is found to agree with quasi-linear theory except for the highest power density cases (QEC/ne2≫1). Radial transport of the energetic electrons with diffusion coefficients of ˜0.4 m2/s is needed to model the broadened ECCD profile at high power density.

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

    Science.gov (United States)

    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.

  2. ATLAS 10 GHz electron cyclotron resonance ion source upgrade project

    Energy Technology Data Exchange (ETDEWEB)

    Moehs, D. P. [Argonne National Laboratory, Physics Division, Argonne, Illinois 60439 (United States); Vondrasek, R. [Argonne National Laboratory, Physics Division, Argonne, Illinois 60439 (United States); Pardo, R. C. [Argonne National Laboratory, Physics Division, Argonne, Illinois 60439 (United States); Xie, D. [Berkeley Ion Equipment Inc., Santa Clara, California 95054 (United States)

    2000-02-01

    A major upgrade of the first ATLAS 10 GHz electron cyclotron resonance (ECR) ion source, which began operations in 1987, is in the planning and procurement phase. The new design will convert the old two-stage source into a single-stage source with an electron donor disk and high gradient magnetic field that preserves radial access for solid material feeds and pumping of the plasma chamber. The new magnetic-field profile allows for the possibility of a second ECR zone at a frequency of 14 GHz. An open hexapole configuration, using a high-energy-product Nd-Fe-B magnet material, having an inner diameter of 8.8 cm and pole gaps of 2.4 cm, has been adopted. Models indicate that the field strengths at the chamber wall, 4 cm in radius, will be 9.3 kG along the magnet poles and 5.6 kG along the pole gaps. The individual magnet bars will be housed in austenitic stainless steel, allowing the magnet housing within the aluminum plasma chamber to be used as a water channel for direct cooling of the magnets. Eight solenoid coils from the existing ECR will be enclosed in an iron yoke to produce the axial mirror. Based on a current of 500 A, the final model predicts a minimum B field of 3 kG with injection and extraction mirror ratios of 4.4 and 2.9, respectively. (c) 2000 American Institute of Physics.

  3. Electron cyclotron resonance heating in a short cylindrical plasma system

    Indian Academy of Sciences (India)

    Vipin K Yadav; D Bora

    2004-09-01

    Electron cyclotron resonance (ECR) plasma is produced and studied in a small cylindrical system. Microwave power is delivered by a CW magnetron at 2.45 GHz in TE10 mode and launched radially to have extraordinary (X) wave in plasma. The axial magnetic field required for ECR in the system is such that the first two ECR surfaces ( = 875.0 G and = 437.5 G) reside in the system. ECR plasma is produced with hydrogen with typical plasma density e as 3.2 × 1010 cm-3 and plasma temperature e between 9 and 15 eV. Various cut-off and resonance positions are identified in the plasma system. ECR heating (ECRH) of the plasma is observed experimentally. This heating is because of the mode conversion of X-wave to electron Bernstein wave (EBW) at the upper hybrid resonance (UHR) layer. The power mode conversion efficiency is estimated to be 0.85 for this system. The experimental results are presented in this paper.

  4. A Michelson Interferometer for Electron Cyclotron Emission Measurements on EAST

    Science.gov (United States)

    Liu, Yong; Stefan, Schmuck; Zhao, Hailin; John, Fessey; Paul, Trimble; Liu, Xiang; Zhu, Zeying; Zang, Qing; Hu, Liqun

    2016-12-01

    A Michelson interferometer, on loan from EFDA-JET (Culham, United Kingdom) has recently been commissioned on the experimental advanced superconducting tokamak (EAST, ASIPP, Hefei, China). Following a successful in-situ absolute calibration the instrument is able to measure the electron cyclotron emission (ECE) spectrum, from 80 GHz to 350 GHz in extraordinary mode (X-mode) polarization, with high accuracy. This allows the independent determination of the electron temperature profile from observation of the second harmonic ECE and the possible identification of non-Maxwellian features by comparing higher harmonic emission with numerical simulations. The in-situ calibration results are presented together with the initial measured temperature profiles. These measurements are then discussed and compared with other independent temperature profile measurements. This paper also describes the main hardware features of the diagnostic and the associated commissioning test results. supported by National Natural Science Foundation of China (Nos. 11405211, 11275233), and the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB106002, 2015GB101000), and the RCUK Energy Programme (No. EP/I501045), partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics (NSFC: No. 11261140328)

  5. Polarization of electron cyclotron emission spectra in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Vries, P.C. de; Nagayama, Y.; Kawahata, K.; Inagaki, S.; Sasao, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Nagasaki, K.

    1999-07-01

    Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD), which has a large shear, complicates the analysis of the ECE spectrum. In a sheared magnetic field the propagation of X and O-mode polarization through the plasma are coupled, causing mode conversion and polarization rotation. Mode scrambling is also caused by wall reflections. In this report, this mode conversion in LHD is numerically analyzed. It was found that at low density mode conversion scrambles the ECE spectra. However, at higher density (n{sub eo} > 1.0{center_dot}10{sup 19} m{sup -3}) the polarization mode is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Wall reflections are found to depolarize the ECE spectrum. Notwithstanding the LHD magnetic configuration, it is shown that temperature profiles could be revealed from the ECE spectra. (author)

  6. ATLAS 10 GHz electron cyclotron resonance ion source upgrade project

    CERN Document Server

    Moehs, D P; Pardo, R C; Xie, D

    2000-01-01

    A major upgrade of the first ATLAS 10 GHz electron cyclotron resonance (ECR) ion source, which began operations in 1987, is in the planning and procurement phase. The new design will convert the old two-stage source into a single-stage source with an electron donor disk and high gradient magnetic field that preserves radial access for solid material feeds and pumping of the plasma chamber. The new magnetic-field profile allows for the possibility of a second ECR zone at a frequency of 14 GHz. An open hexapole configuration, using a high-energy-product Nd-Fe-B magnet material, having an inner diameter of 8.8 cm and pole gaps of 2.4 cm, has been adopted. Models indicate that the field strengths at the chamber wall, 4 cm in radius, will be 9.3 kG along the magnet poles and 5.6 kG along the pole gaps. The individual magnet bars will be housed in austenitic stainless steel, allowing the magnet housing within the aluminum plasma chamber to be used as a water channel for direct cooling of the magnets. Eight solenoid...

  7. Heating and Current Drive by Electron Cyclotron Waves

    Science.gov (United States)

    Prater, R.

    2003-10-01

    The physics model of electron cyclotron heating (ECH) and current drive (ECCD) is becoming well validated through systematic comparisons of theory and experiment. Work has shown that ECCD can be highly localized and robustly controlled, leading to applications including stabilization of MHD instabilities like neoclassical tearing modes, control and sustainment of desired profiles of current density and plasma pressure, and studies of localized transport. These physics applications and the study of the basic physics of ECH and ECCD were enabled by the advent of the gyrotron in the 1980s and of the diamond window for megawatt gyrotrons in the 1990s. The experimental work stimulated a broad base of theory based on first principles which is encapsulated in linear ray tracing codes and fully relativistic quasilinear Fokker-Planck codes. Recent experiments use measurements of the local poloidal magnetic field through the motional Stark effect to determine the magnitude and profile of the locally driven current. The subtle balance between wave-induced diffusion and Coulomb relaxation in velocity space provides an understanding of the effects of trapping of current-carrying electrons in the magnetic well, an effect which can be used to advantage. Strong quasilinear effects and radial transport of electrons which may broaden the driven current profile have also been observed under some conditions and appear to be consistent with theory, but in large devices these are usually insignificant. Additional advantages of ECH compared with other rf heating methods are that the antenna can be far removed from the plasma and the power density can be very high. The agreement of theory and experiment, the broad base of established applications, and the technical advantages of ECH support the application of ECH in next-step tokamaks and stellarators.

  8. Electron cyclotron plasma startup in the GDT experiment

    Science.gov (United States)

    Yakovlev, D. V.; Shalashov, A. G.; Gospodchikov, E. D.; Solomakhin, A. L.; Savkin, V. Ya.; Bagryansky, P. A.

    2017-01-01

    We report on a new plasma startup scenario in the gas dynamic trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) plasma heating system fires into a sufficiently dense plasma target (‘seed plasma’), which is commonly supplied by an arc plasma generator. In the reported experiments, a different approach to seed plasma generation is explored. One of the channels of the electron cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of plasma to a level suitable for NBI capture. After a short transition of approximately 1 ms the discharge becomes essentially similar to a standard one initiated by the plasma gun. This paper presents the discharge scenario and experimental data on the seed plasma evolution during ECRH, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of the consequent high-power NBI discharge are studied and differences from the conventional scenario are discussed. A theoretical model describing the ECR breakdown and the seed plasma accumulation in a large-scale mirror trap is developed on the basis of the GDT experiment.

  9. Electron-cyclotron plasma startup in the GDT experiment

    CERN Document Server

    Yakovlev, D V; Gospodchikov, E D; Solomakhin, A L; Savkin, V Ya; Bagryansky, P A

    2016-01-01

    The paper reports on a new plasma startup scenario in the Gas Dynamic Trap (GDT) magnetic mirror device. The primary 5 MW neutral beam injection (NBI) plasma heating system fires into a sufficiently dense plasma target ("seed plasma"), which is commonly supplied by an arc plasma generator. In the reported experiments, a different approach to seed plasma generation is explored. One of the channels of the electron cyclotron resonance (ECR) heating system is used to ionize the neutral gas and build up the density of plasma to a level suitable for NBI capture. After a short transition (about 1 ms) the discharge becomes essentially similar to a standard one initiated by the plasma gun. The paper presents the discharge scenario and experimental data on the seed plasma evolution during ECR heating, along with the dependencies on incident microwave power, magnetic configuration and pressure of a neutral gas. The characteristics of consequent high-power NBI discharge are studied and differences to the conventional sce...

  10. Current drive by electron cyclotron waves in stellarators

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Alejaldre, C.; Coarasa, J. A.

    1992-07-01

    In this paper we propose a method to estimate the induced current by Electron Cyclotron waves fast enough, from the numerical point of view, to be included in a ray-tracing code, and yet accounting for the complicated geometry of stellarators. Since trapped particle effects are particularly important in this Current Drive method and in stellarator magnetic configuration, they are considered by the modification they introduce in the current drive efficiency. Basically, the method consists of integrating the Fisch and Boozer relativistic efficiency, corrected with the effect of trapped particles, times the absorbed power per momentum interval. This one is calculated for a Maxwellian distribution function, assuming a nearly linear regime. The influence of impurities and of species which are not protons is studied, calculating the efficiency for plasmas with Zeff) - Finally, a numerical analysis particularized to TJ-II stellarator is presented. The absorbed power density is calculated by the ray tracing code RAYS, taking into account the actual microwave beam structure. (Author) 23 refs.

  11. Cyclotron radiation cooling of a short electron bunch kicked in an undulator with guiding magnetic field

    Directory of Open Access Journals (Sweden)

    I. V. Bandurkin

    2015-11-01

    Full Text Available We propose to use of an undulator with the guiding axial magnetic field as a “kicker” forming a bunch of electron gyro-oscillators with a small spread in the axial velocity. The cyclotron emission from the bunch leads to losing oscillatory velocity of electron gyrorotation, but it does not perturb the axial electron velocity. This effect can be used for transformation of minimization of the spread in electron axial velocity in the undulator section into minimization of the spread in electron energy in the cyclotron radiation section.

  12. First results of electron cyclotron emission measurements at the GDT magnetic mirror

    CERN Document Server

    Shalashov, A G; Gospodchikov, E D; Lubyako, L V; Yakovlev, D V; Bagryansky, P A

    2016-01-01

    This paper summarizes the results of experiments on electron cyclotron emission (ECE) measurements at the fundamental harmonic recently performed at the axially symmetric magnetic mirror device GDT (Budker Institute, Novosibirsk). New ECE diagnostics is installed to facilitate the successful electron cyclotron resonance heating experiment and operates in the vicinity of the heating frequency of 54.5 GHz. Besides expected emission of thermal electrons, a clearly resolved non-thermal ECE is observed indicating the presence of suprathermal electrons driven by high-power microwave heating. The particulars of plasma emission are studied experimentally in a broad range of discharge scenarios.

  13. Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

    DEFF Research Database (Denmark)

    Hellsten, T.; Johnson, T. J.; Van Eester, D.

    2012-01-01

    The rotation of L-mode plasmas in the JET tokamak heated by waves in the ion cyclotron range of frequencies (ICRF) damped on electrons, is reported. The plasma in the core is found to rotate in the counter-current direction with a high shear and in the outer part of the plasma with an almost...... constant angular rotation. The core rotation is stronger in magnitude than observed for scenarios with dominating ion cyclotron absorption. Two scenarios are considered: the inverted mode conversion scenarios and heating at the second harmonic He-3 cyclotron resonance in H plasmas. In the latter case......, electron absorption of the fast magnetosonic wave by transit time magnetic pumping and electron Landau damping (TTMP/ELD) is the dominating absorption mechanism. Inverted mode conversion is done in (He-3)-H plasmas where the mode converted waves are essentially absorbed by electron Landau damping. Similar...

  14. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

    Science.gov (United States)

    Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

    2012-12-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

  15. Fast Ion Induced Shearing of 2D Alfven Eigenmodes Measured by Electron Cyclotron Emission Imaging

    NARCIS (Netherlands)

    Tobias, B. J.; Classen, I.G.J.; Domier, C.W.; Heidbrink, W. W.; N C Luhmann Jr.,; Nazikian, R.; Park, H. K.; Spong, D. A.; VanZeeland, M. A.

    2011-01-01

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfven eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the o

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

    CERN Document Server

    Chapman, I T; 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

    2013-01-01

    13MW 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 neo-classical 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 alpha particle stabilisation 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 sig...

  17. Electron temperature fluctuation in the HT-7 tokamak plasma observed by electron cyclotron emission imaging

    Institute of Scientific and Technical Information of China (English)

    Xu Xiao-Yuan; Wang Jun; Yu Yi; Wen Yi-Zhi; Yu Chang-Xuan; Liu Wan-Dong; Wan Bao-Nian; Gao Xiang; N. C. Luhmann; C. W. Domier; Jian Wang; Z. G. Xia; Zuowei Shen

    2009-01-01

    The fluctuation of the electron temperature has been measured by using the electron cyclotron emission imaging in the Hefei Tokamak-7 (HT-7) plasma. The electron temperature fluctuation with a broadband spectrum shows that it propagates in the electron diamagnetic drift direction, and the mean poloidal wave-number kg is calculated to be about 1.58 cm-1, or keps ≈0.34. It indicates that the fluctuation should come from the electron drift wave turbulence. The linear global scaling of the electron temperature fluctuation with the gradient of electron temperature is consistent with the mixing length scale qualitatively. Evolution of spectrum of the fluctuation during the sawtooth oscillation phases is investigated, and the fluctuation is found to increase with the gradient of electron temperature increasing during most phases of the sawtooth oscillation. The results indicate that the electron temperature gradient is probably the driver of the fluctuation enhancement. The steady heat flux driven by electron temperature fluctuation is estimated and compared with the results from power balance estimation.

  18. Ordinary-mode fundamental electron cyclotron resonance absorption and emission in the Princeton Large Torus

    Energy Technology Data Exchange (ETDEWEB)

    Efthimion, P.C.; Arunasalam, V.; Hosea, J.C.

    1979-11-01

    Fundamental electron cyclotron resonance damping for 4 mm waves with ordinary polarization is measured for propagation along the major radius traversing the midplane of the plasma in the Princeton Large Torus (PLT). Optical depths obtained from the data are in good agreement with those predicted by the relativistic hot plasma theory. Near blackbody emission over much of the plasma midplane is obtained and, in conjunction with the damping measurements, indicates that the vessel reflectivity is high. The practical use of ordinary mode fundamental electron cyclotron resonance heating (ECRH) in existing and future toroidal devices is supported by these results.

  19. Cyclotron resonance in two-dimensional electron system with self-organized antidots

    CERN Document Server

    Suchalkin, S D; Zundel, M; Nachtwei, G; Klitzing, K V; Eberl, K

    2001-01-01

    The data on the experimental study on the cyclotron resonance in the two-dimensional electron system with the random scattering potential, conditioned by the massif of the AlInAs self-organized quantum islands, formed in the AlGaAs/GaAs heterotransition plane, are presented. The sharp narrowing of the cyclotron resonance with increase in the magnetic field, explained by the charge scattering peculiarities in the given potential is established. The obtained results suggest the strongly correlated electron state in the strong magnetic fields by the carriers concentrations lesser than the antidots concentrations

  20. Kinetic instabilities in pulsed operation mode of a 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O., E-mail: olli.tarvainen@jyu.fi; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J. [Department of Physics, University of Jyväskylä, 40500 Jyväskylä (Finland); Izotov, I.; Mansfeld, D. [Institute of Applied Physics, RAS, 46 Ul‘yanova St., 603950 Nizhny Novgorod (Russian Federation); Skalyga, V. [Institute of Applied Physics, RAS, 46 Ul‘yanova St., 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., 603950 Nizhny Novgorod (Russian Federation)

    2016-02-15

    The occurrence of kinetic plasma instabilities is studied in pulsed operation mode of a 14 GHz A-electron cyclotron resonance type electron cyclotron resonance ion source. It is shown that the temporal delay between the plasma breakdown and the appearance of the instabilities is on the order of 10-100 ms. The most important parameters affecting the delay are magnetic field strength and neutral gas pressure. It is demonstrated that kinetic instabilities limit the high charge state ion beam production in the unstable operating regime.

  1. Electron cyclotron emission diagnostic systems for electron temperature perturbation measurement in JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Isayama, Akihiko; Isei, Nobuaki; Ishida, Shinichi; Sato, Minoru [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2000-03-01

    Three systems are now operational in JT-60U tokamak for the measurement of electron cyclotron emissions. They are the Fourier transform spectrometer, 20 channels grating polychrometer, and 24 channels heterodyne radiometer. The first system has been absolutely calibrated, and used in the relative calibration of remaining two systems. The paper describes major specifications and recent upgrading of each system. In JT-60U experiments, the heterodyne radiometer system is mainly used for electron temperature perturbations with high signal-to-noise ratio. One of the disadvantage of this system is that the measurement points uniquely determined by the toroidal field, and thus cannot be chosen freely. In the experiment the third system, grating polychrometer, which allows free choice of measurement points, is used to cover the wide cross-section of the JT-60U plasma. (author)

  2. Prospects for advanced electron cyclotron resonance and electron beam ion source charge breeding methods for EURISOL

    Energy Technology Data Exchange (ETDEWEB)

    Delahaye, P.; Jardin, P.; Maunoury, L.; Traykov, E.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd. Becquerel, BP 55027, 14076 Caen Cedex 05 (France); Galata, A.; Porcellato, A. M.; Prete, G. F. [INFN-Laboratori Nazionali di Legnaro, Viale dell' Universita 2, 35020 Legnaro, Padova (Italy); Angot, J.; Lamy, T.; Sortais, P.; Thuillier, T. [LPSC Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Ban, G. [LPC Caen, 6 bd Marechal Juin, 14050 Caen Cedex (France); Celona, L.; Lunney, D. [INFN-Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Choinski, J.; Gmaj, P.; Jakubowski, A.; Steckiewicz, O. [Heavy Ion Laboratory, University of Warsaw, ul. Pasteura 5a, 02 093 Warsaw (Poland); Kalvas, T. [Department of Physics, University of Jyvaeskylae, PB 35 (YFL) 40351 Jyvaeskylae (Finland); 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.

  3. A relativistic model of electron cyclotron current drive efficiency in tokamak plasmas

    OpenAIRE

    Lin-Liu Y.R.; Hu Y.J.; Hu Y.M.

    2012-01-01

    A fully relativistic model of electron cyclotron current drive (ECCD) efficiency based on the adjoint function techniques is considered. Numerical calculations of the current drive efficiency in a tokamak by using the variational approach are performed. A fully relativistic extension of the variational principle with the modified basis functions for the Spitzer function with momentum conservation in the electron-electron collision is described in general tokamak geometry. The model developed ...

  4. Advanced launcher design options for electron cyclotron current drive on ITER based on remote steering

    NARCIS (Netherlands)

    Graswinckel, M. R.; Bongers, W. A.; M.R. de Baar,; van den Berg, M. A.; Denisov, G.; Donne, A. J. H.; Elzendoorn, B. S. Q.; Goede, A. P. H.; Heidinger, R.; Kuzikov, S.; Kruijt, O. G.; Kruizinga, B.; Moro, A.; Poli, E.; Ronden, D. M. S.; Saibene, G.; Thoen, D. J.; Verhoeven, A. G. A.

    2008-01-01

    Electron cyclotron current drive will become the main scheme on ITER for the stabilization of neoclassical tearing modes (NTMs) and the control of sawtooth oscillations. The effectiveness of this scheme forms the basis for the requirements of the ITER Upper Port Launcher. These requirements include

  5. Electron cyclotron heating and current drive in toroidal geometry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kritz, A.H.

    1991-11-01

    The Principal Investigator has continued to work on problems associated both with the deposition and with the emission of electron cyclotron power in toroidal plasmas. We have investigated the use of electron cyclotron resonance heating for bringing compact tokamaks (BPX) to ignition-like parameters. This requires that we continue to refine the modeling capability of the TORCH code linked with the BALDUR 1 {1/2} D transport code. Using this computational tool, we have examined the dependence of ignition on heating and transport employing both theoretical (multi-mode) and empirically based transport models. The work on current drive focused on the suppression of tearing modes near the q = 2 surface and sawteeth near the q = 1 surface. Electron cyclotron current drive in CIT near the q =2 surface was evaluated for a launch scenario where electron cyclotron power was launched near the equatorial plane. The work on suppression of sawteeth has been oriented toward understanding the suppression that has been observed in a number of tokamaks, in particular, in the WT-3 tokamak in Kyoto. To evaluate the changes in current profile (shear) near the q =1 surface, simulations have been carried out using the linked BALDUR-TORCH code. We consider effects on shear resulting both from wave-induced current as well as from changes in conductivity associated with changes in local temperature. Abstracts and a paper relating to this work is included in Appendix A.

  6. Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

    NARCIS (Netherlands)

    Hellsten, T.; Johnson, T. J.; Van Eester, D.; Lerche, E.; Lin, Y.; Mayoral, M. L.; Ongena, J.; Calabro, G.; Crombe, K.; Frigione, D.; Giroud, C.; Lennholm, M.; Mantica, P.; Nave, M. F. F.; Naulin, V.; Sozzi, C.; Studholme, W.; Tala, T.; Versloot, T.

    2012-01-01

    The rotation of L-mode plasmas in the JET tokamak heated by waves in the ion cyclotron range of frequencies (ICRF) damped on electrons, is reported. The plasma in the core is found to rotate in the counter-current direction with a high shear and in the outer part of the plasma with an almost constan

  7. Isotopic anomaly for carbon ions in an electron cyclotron resonance ion source

    NARCIS (Netherlands)

    Drentje, A. G.; Kitagawa, A.; Muramatsu, M.

    2010-01-01

    In many experiments methods were applied to increase the highly charged ion output from an electron cyclotron resonance ion source; the gas-mixing method is still generally being applied. The dominant role of the masses of the ions in the gas-mixture was apparent. Two basically differing mechanisms

  8. Techniques and mechanisms applied in electron cyclotron resonance sources for highly charged ions

    NARCIS (Netherlands)

    Drentje, AG

    2003-01-01

    Electron cyclotron resonance ion sources are delivering beams of highly charged ions for a wide range of applications in many laboratories. For more than two decades, the development of these ion sources has been to a large extent an intuitive and experimental enterprise. Much effort has been spent

  9. Commissioning of electron cyclotron emission imaging instrument on the DIII-D tokamak and first data

    NARCIS (Netherlands)

    Tobias, B.; Domier, C.W.; Liang, T.; Kong, X.; Yu, L.; Yun, G. S.; Park, H. K.; Classen, I.G.J.; Boom, J. E.; Donne, A. J. H.; Munsat, T.; Nazikian, R.; Van Zeeland, M.; Boivin, R. L.; N C Luhmann Jr.,

    2010-01-01

    A new electron cyclotron emission imaging diagnostic has been commissioned on the DIII-D tokamak. Dual detector arrays provide simultaneous two-dimensional images of T-e fluctuations over radially distinct and reconfigurable regions, each with both vertical and radial zoom capability. A total of 320

  10. An overview of control system for the ITER electron cyclotron system

    NARCIS (Netherlands)

    Purohit, D.; Bigelow, T.; Billava, D.; Bonicelli, T.; Caughman, J.; Darbos, C.; Denisov, G.; Gandini, F.; Gassmann, T.; Henderson, M.; Journeux, J. Y.; Kajiwara, K.; Kobayashi, N.; Nazare, C.; Oda, Y.; Omori, T.; Rao, S. L.; Rasmussen, D.; Ronden, D.; Saibene, G.; Sakamoto, K.; Sartori, F.; Takahashi, K.; Temkin, R.

    2011-01-01

    The ITER electron cyclotron (EC) system having capability of up to 26 MW generated power at 170 GHz is being procured by 5 domestic agencies via 10 procurement arrangements. This implies diverse types of equipment and complex interface management. It also places a challenge on control system archite

  11. Status of the PHOENIX electron cyclotron resonance charge breeder at ISOLDE, CERN.

    Science.gov (United States)

    Barton, Charles; Cederkall, Joakim; Delahaye, Pierre; Kester, Oliver; Lamy, Thierry; Marie-Jeanne, Mélanie

    2008-02-01

    We report here on the last progresses made with the PHOENIX electron cyclotron resonance charge breeder test bench at ISOLDE. Recently, an experiment was performed to test the trapping of (61)Fe daughter nuclides from the decay of (61)Mn nuclides. Preliminary results are given.

  12. Three-wave interaction during electron cyclotron resonance heating and current drive

    DEFF Research Database (Denmark)

    Nielsen, Stefan Kragh; Jacobsen, Asger Schou; Hansen, Søren Kjer

    2016-01-01

    Non-linear wave-wave interactions in fusion plasmas, such as the parametric decay instability (PDI) of gyrotron radiation, can potentially hamper the use of microwave diagnostics. Here we report on anomalous scattering in the ASDEX Upgrade tokamak during electron cyclotron resonance heating...

  13. Design and installation of the electron cyclotron wave system for the TCV tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, T.P.; Alberti, S.; Henderson, M.A.; Pochelon, A.; Tran, M.Q. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1996-10-01

    The design of a combined 82.7 GHz and 118 GHz, 4.5 MW, 2.0 s electron cyclotron wave (ECW) system for heating and current drive on TCV is described. Low and high power test results of the RF source, transmission line and launching antenna are presented. (author) 3 figs., 5 refs.

  14. Closure of the single fluid magnetohydrodynamic equations in presence of electron cyclotron current drive

    NARCIS (Netherlands)

    Westerhof, E.; Pratt, J.

    2014-01-01

    In the presence of electron cyclotron current drive (ECCD), the Ohm's law of single fluid magnetohydrodynamics is modified as E + v × B = η(J – J EC). This paper presents a new closure relation for the EC driven current density appearing in this modified Ohm's law. The new relation faithfu

  15. Simulation on the electronic wave packet cyclotron motion in a Weyl semimetal slab.

    Science.gov (United States)

    Yao, Haibo; Zhu, Mingfeng; Jiang, Liwei; Zheng, Yisong

    2017-04-20

    We perform a numerical simulation on the time evolution of an electronic wave packet in a Weyl semimetal (WSM) slab driven by a magnetic field. We find that the evolution trajectory of the wave packet depends sensitively on its initial spin state. Only with initial spin state identical to that of the Fermi arc state at the surface it localized, does the wave packet evolution demonstrate the characteristic cyclotron orbit of WSM previously predicted from a semiclassical viewpoint. By analyzing the eigen-expansion of the electronic wave packet, we find the chiral Landau levels (LLs) of the WSM slab, as ingredients of the wave packet, to be responsible for establishing the characteristic WSM cyclotron orbit. In contrast, the nonchiral LLs contribute irregular oscillations to the wave packet evolution, going against the formation of a well-defined cyclotron orbit. In addition, the tilted magnetic field does not affect the motion of the electronic wave packet along the Fermi arcs in the momentum space. It does, however, alter the evolution trajectory of the electronic wave packet in real space and spin space. Finally, the energy disalignment of the Weyl nodes results in a 3D cyclotron orbit in real space.

  16. Techniques and mechanisms applied in electron cyclotron resonance sources for highly charged ions

    NARCIS (Netherlands)

    Drentje, AG

    Electron cyclotron resonance ion sources are delivering beams of highly charged ions for a wide range of applications in many laboratories. For more than two decades, the development of these ion sources has been to a large extent an intuitive and experimental enterprise. Much effort has been spent

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

    Science.gov (United States)

    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.

  18. Potential applications of an electron cyclotron resonance multicusp plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.C.; Berry, L.A.; Gorbatkin, S.M.; Haselton, H.H.; Roberto, J.B.; Schechter, D.E.; Stirling, W.L.

    1990-03-01

    An electric cyclotron resonance (ECR) multicusp plasmatron has been developed by feeding a multicusp bucket arc chamber with a compact ECR plasma source. This novel source produces large (about 25-cm- diam), uniform (to within {plus minus}10%), dense (>10{sup 11}--cm{sup {minus}3}) plasmas of argon, helium, hydrogen, and oxygen. It has been operated to produce an oxygen plasma for etching 12.7-cm (5-in.) positive photoresist-coated silicon wafers with uniformity within {plus minus}8%. Following a brief review of the large plasma source developed at Oak Ridge National Laboratory, the configuration and operation of the source are described and a discharge model is presented. Results from this new ECR plasma source and potential applications for plasma processing of thin films are discussed. 21 refs., 10 figs.

  19. On the application of electron cyclotron emission imaging to the validation of theoretical models of magnetohydrodynamic activity

    NARCIS (Netherlands)

    Tobias, B. J.; Boivin, R. L.; Boom, J. E.; Classen, I.G.J.; Domier, C.W.; Donne, A. J. H.; Heidbrink, W. W.; N C Luhmann Jr.,; Munsat, T.; Muscatello, C. M.; Nazikian, R.; Park, H. K.; Spong, D. A.; Turnbull, A. D.; VanZeeland, M. A.; Yun, G. S.

    2011-01-01

    Two-dimensional (2D) imaging of electron temperature perturbations provides a powerful constraint for validating theoretical models describing magnetohydrodynamic plasma behavior. In observation of Alfven wave induced temperature fluctuations, electron cyclotron emission imaging provides unambiguous

  20. Kinetic simulation of the electron-cyclotron maser instability: effect of a finite source size

    CERN Document Server

    Kuznetsov, A A

    2012-01-01

    The electron-cyclotron maser instability is widespread in the Universe, producing, e.g., radio emission of the magnetized planets and cool substellar objects. Diagnosing the parameters of astrophysical radio sources requires comprehensive nonlinear simulations of the radiation process. We simulate the electron-cyclotron maser instability in a very low-beta plasma. The model used takes into account the radiation escape from the source region and the particle flow through this region. We developed a kinetic code to simulate the time evolution of an electron distribution in a radio emission source. The model includes the terms describing the particle injection to and escape from the emission source region. The spatial escape of the emission from the source is taken into account by using a finite amplification time. The unstable electron distribution of the horseshoe type is considered. A number of simulations were performed for different parameter sets typical of the magnetospheres of planets and ultracool dwarf...

  1. Multicusp type electron cyclotron resonance plasma with arrangement of permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, H.; Maeda, M. [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1995-09-01

    ECR (electron cyclotron resonance) plasmas are generated in a multicusp field of 12-pole formed by permanent magnets, where the polarity of the magnetic field at the end sections is reversed to reflect axially drifting electrons as in the mirror field. Furthermore, the radius of multicusp is contracted below the cut-off radius of the waveguide in vacuum. This is effective in increasing the microwave power absorbed in the plasma and the ion density. (author).

  2. RF current drive by electron cyclotron waves in the presence of magnetic islands

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva Rosa, P.; Giruzzi, G

    1999-11-01

    The influence of the presence of magnetic islands, and the consequent modification of the tokamak magnetic surface topology, on electron current drive is analyzed. To this end, a new 3D Fokker-Planck code has been developed, taking into account the modifications of the magnetic equilibrium topology owing to the presence of the islands. Significant differences between electron cyclotron current drive efficiency with and without island inside the plasma are found, particularly in the case of interaction with locked modes. (authors)

  3. Characteristics of heat flux and electromagnetic electron-cyclotron instabilities driven by solar wind electrons

    Science.gov (United States)

    Saeed, Sundas; Yoon, P. H.; Sarfraz, M.; Qureshi, M. N. S.

    2017-04-01

    In situ observations reveal the existence of electron velocity distribution function in the solar wind, where the net distribution can be modelled by a combination of core, halo and strahl. These components often possess a relative drift and with respective temperature anisotropies. The relative drift between the core and halo components leads to heat flux (HF) instability, while temperature anisotropies drive electromagnetic electron-cyclotron (EMEC) instability. These instabilities have been separately studied in the literature, but for the first time, the present study combines both unstable modes in the presence of two free energy sources, namely, excessive parallel pressure and excessive perpendicular temperature. HF instability (which is a left-hand circularly polarized mode) is effectively similar to electron firehose instability, except that the free energy is provided by net relative drift among two component electrons in the background of protons. The HF instability is discussed here along with (the right-hand polarized) EMEC instability driven by temperature anisotropy. The unstable HF mode is conventionally termed the 'whistler' HF instability, but it is actually polarized in the opposite sense to the whistler wave. EMEC mode, on the other hand, reduces to the proper whistler wave in the absence of free energy source. The present combined analysis clarifies the polarization characteristics of these two modes in an unambiguous manner.

  4. The effect of electron holes on cyclotron maser emission driven by horseshoe distributions

    CERN Document Server

    Zhao, G Q; Feng, H Q; Wu, D J

    2016-01-01

    This Brief Communication presents a quantitative investigation for the effect of electron holes on electron-cyclotron maser (ECM) driven by horseshoe distributions. The investigation is based on an integrated distribution function for the horseshoe distributions with electron holes. Results show that the presence of electron holes can significantly enhance the ECM growth rate by 2-3 times in a very narrow waveband. The present study suggests that these electron holes probably are responsible for some fine structures of radiations, such as narrowband events in auroral kilometric radiation and solar microwave spikes.

  5. The effect of electron holes on cyclotron maser emission driven by horseshoe distributions

    Science.gov (United States)

    Zhao, G. Q.; Chu, Y. H.; Feng, H. Q.; Wu, D. J.

    2016-11-01

    This Brief Communication presents a quantitative investigation for the effect of electron holes on electron-cyclotron maser (ECM) driven by horseshoe distributions. The investigation is based on an integrated distribution function for the horseshoe distributions with electron holes. Results show that the presence of electron holes can significantly enhance the ECM growth rate by 2-3 times in a very narrow waveband. The present study suggests that these electron holes probably are responsible for some fine structures of radiations, such as narrowband events in auroral kilometric radiation and solar microwave spikes.

  6. Gallium-assisted growth of silicon nanowires by electron cyclotron resonance plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M J; Cervera, M; Ruiz, E; Pau, J L; Piqueras, J [Laboratorio de Microelectronica, Departamento de Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Avella, M; Jimenez, J, E-mail: maria.jesus.hernandez@uam.es [Fisica de la Materia Condensada, ETSII, Universidad de Valladolid, 47011 Valladolid (Spain)

    2010-11-12

    The use of gallium droplets for growing Si nanowires (SiNWs) by electron cyclotron resonance plasmas is investigated. First, the relationship between evaporation time and resultant size of the gallium droplets is studied. Through the use of spectroscopic ellipsometry, the dependence of the surface plasmon resonance (SPR) energy on the droplet size is determined. From these gallium droplets, SiNWs were grown at 300 and 550 deg. C in electron cyclotron resonance plasmas containing SiH{sub 4}, Ar, and H{sub 2}. Scanning electron microscopy results show that tapered NWs are obtained for a wide range of growth conditions. Besides, it is found that H{sub 2} plays an important role in the parasitic axial growth of the SiNWs. Namely, H{sub 2} inhibits the radial growth and contributes dramatically to increasing the SiNW defects.

  7. Quasi-3D electron cyclotron emission imaging on J-TEXT

    Science.gov (United States)

    Zhao, Zhenling; Zhu, Yilun; Tong, Li; Xie, Jinlin; Liu, Wandong; Yu, Changxuan; Yang, Zhoujun; Zhuang, Ge; Luhmann, N. C., Jr.; Domier, C. W.

    2017-09-01

    Electron cyclotron emission imaging (ECEI) can provide measurements of 2D electron temperature fluctuation with high temporal and spatial resolution in magnetic fusion plasma devices. Two ECEI systems located in different toroidal ports with 67.5 degree separation have been implemented on J-TEXT to study the 3D structure of magnetohydrodynamic (MHD) instabilities. Each system consists of 12 (vertical) × 16 (horizontal) = 192 channels and the image of the 2nd harmonic X-mode electron cyclotron emission can be captured continuously in the core plasma region. The field curvature adjustment lens concept is developed to control the imaging plane for receiving optics of the ECEI systems. Field curvature of the image can be controlled to match the emission layer. Consequently, a quasi-3D image of the MHD instability in the core of the plasma has been achieved.

  8. Advancements in electron cyclotron emission imaging demonstrated by the TEXTOR ECEI diagnostic upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, B.; Kong, X.; Liang, T.; Spear, A.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Classen, I. G. J.; Boom, J. E.; Pol, M. J. van de; Jaspers, R.; Donne, A. J. H. [Association EURATOM-FOM, FOM Institute for Plasma Physics Rijnhuizen, Trilateral Euregio Cluster, 3430 BE Nieuwegein (Netherlands); Park, H. K. [Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Munsat, T. [University of Colorado at Boulder, Boulder, Colorado 80309 (United States)

    2009-09-15

    A new TEXTOR electron cyclotron emission imaging system has been developed and employed, providing a diagnostic with new features and enhanced capabilities when compared to the legacy system it replaces. Optical coupling to the plasma has been completely redesigned, making use of new minilens arrays for reduced optical aberration and providing the new feature of vertical zoom, whereby the vertical coverage is now remotely adjustable on a shot-by-shot basis from 20-35 cm. Other innovations, such as the implementation of stacked quasioptical planar notch filters, allow for the diagnostic to be operated without interruption or degradation in performance during electron cyclotron resonance heating. Successful commissioning of the new diagnostic and a demonstration of the improved capabilities are presented in this paper, along with a discussion of the new technologies employed.

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

    Science.gov (United States)

    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.

  10. Cerenkov and cyclotron Cerenkov instabilities in a dielectric loaded parallel plate waveguide sheet electron beam system

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Ding; Ding Yaogen [Key Laboratory of High Power Microwave Sources and Technologies, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-09-15

    A dielectric loaded parallel plate waveguide sheet electron beam system can be taken as a reliable model for the practical dielectric loaded rectangular waveguide sheet beam system that has a transverse cross section with a large width to height ratio. By using kinetic theory, the dispersion equations for Cerenkov and cyclotron Cerenkov instabilities in the parallel plate waveguide sheet beam system have been obtained rigorously. The dependences of the growth rate of both instabilities on the electric and structural parameters have also been investigated in detail through numerical calculations. It is worthwhile to point out that adopting an electron beam with transverse velocity can evidently improve the growth rate of Cerenkov instability, which seems like the case of cyclotron Cerenkov instability.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. Plasma instability in the afterglow of electron cyclotron resonance discharge sustained in a mirror trap

    Energy Technology Data Exchange (ETDEWEB)

    Izotov, I.; Mansfeld, D.; Skalyga, V.; Zorin, V. [Institute of Applied Physics, RAS, 46 Ulyanova St., 603950 Nizhny Novgorod (Russian Federation); Grahn, T.; Kalvas, T.; Koivisto, H.; Komppula, J.; Peura, P.; Tarvainen, O.; Toivanen, V. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), 40500 Jyvaeskylae (Finland)

    2012-12-15

    The work presented in this article is devoted to time-resolved diagnostics of non-linear effects observed during the afterglow plasma decay of a 14 GHz electron cyclotron resonance ion source operated in pulsed mode. Plasma instabilities that cause perturbations of the extracted ion current during the decay were observed and studied. It is shown that these perturbations are associated with precipitation of high energy electrons along the magnetic field lines and strong bursts of bremsstrahlung emission. The effect of ion source settings on the onset of the observed instabilities was investigated. Based on the experimental data and estimated plasma properties, it is assumed that the instabilities are of cyclotron type. The conclusion is supported by a comparison to other types of plasma devices which exhibit similar characteristics but which operate in a different plasma confinement regime.

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

    Science.gov (United States)

    Vondrasek, R; Pardo, R; Scott, R

    2013-11-01

    An electron cyclotron resonance ion source has been utilized to produce mercury beams with intensities of 4.5 eμA of (202)Hg(29+) and 3.0 eμA of (202)Hg(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.

  15. Development of electron cyclotron emission imaging system on Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahara, D.; Tsuji-Iio, S. [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8550 (Japan); Nagayama, Y.; Yoshinaga, T.; Tsuchiya, H.; Sugito, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Yamaguchi, S. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Kogi, Y. [Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Fukuoka 811-0295 (Japan); Akaki, K.; Mase, A. [KASTEC, Kyushu University, 6-1 Kasuga-Koen, Kasuga, Fukuoka 816-8580 (Japan)

    2010-10-15

    A combined system of microwave imaging reflectometry and electron cyclotron emission (ECE) imaging has been developed for the Large Helical Device. This system includes a wide-band two-dimensional horn-antenna mixer array (HMA). The HMA consists of horn antennas, waveguides, mixers, and intermediate frequency circuits. The frequency response of the HMA is between 50 and 110 GHz. The ECE signal is selected using a 95 GHz local oscillator and a 93 GHz high-pass filter.

  16. Risk mitigation strategy for the ITER electron cyclotron upper port launcher

    OpenAIRE

    Goede, A. P. H.; Bongers, W. A.; Elzendoorn, B. S. Q.; Graswinckel, M. F.; M.R. de Baar

    2010-01-01

    A basic requirement for ITER equipment to meet is a high level of reliability, because ITER operation time is precious and radioactive operation leaves limited scope for repair. In order to reduce the risk of failure during ITER operation an effective risk mitigation strategy is necessary. This paper presents such strategy for the ITER electron cyclotron upper port launcher (ECUPL). A preliminary ECUPL risk analysis identifies possible failure modes. A probabilistic risk assessment quantifies...

  17. Identification of fast particle triggered modes by means of correlation electron cyclotron emission on Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Goniche, M.; Huysmans, G.T.A.; Turco, F.; Maget, P.; Segui, J.L.; Artaud, J.F.; Giruzzi, G.; Imbeaux, F.; Lotte, P.; Mazon, D.; Molina, D. [CEA Cadarache, Assoc EURATOM DRFC, SCCP, F-13108 St Paul Les Durance (France); Udintsev, V.S. [EPFL /SB/CRPP, Assoc EURATOM Confederat Suisse, CH-1015 Lausanne (Switzerland)

    2008-07-01

    Low-frequency (5- to 20-kHz) and high-frequency (40- to 200-kHz) modes are studied during radio-frequency heating experiments on the Tore Supra tokamak by means of correlation electron cyclotron emission. High-frequency modes are detected when the plasma is heated by ion cyclotron range of frequency waves in the minority D(H) heating scheme in combination with lower hybrid current drive (LHCD) producing a flat or slightly reversed q-profile. They are identified as Alfven cascade modes. When this mode is triggered, fast ion losses ({<=} 20%) are detected from the neutron emission rate, and an additional heat load on plasma-facing components can be measured by an infrared camera when the fast ion energy is sufficiently large. Low-frequency modes are commonly triggered during LHCD experiments performed at low loop voltage. This mode can be observed with moderate lower hybrid power when the q-profile is monotonic or at higher power when the q-profile is flat in the core (r/a {<=} 0.2) or reversed. It is identified, in most cases, as an electron fishbone-like mode. These modes can be stabilized by a slight modification of the q-profile provided by an increase of lower hybrid power or by a small addition of electron cyclotron current device. (authors)

  18. Simulation of Electron Behavior in PIG Ion Source for 9MeV Cyclotron

    CERN Document Server

    Ghergherehchi, Mitra; Yeon, Yeong- Heum; Chai, Jong- Seo

    2013-01-01

    In this paper, we focus on a PIG source for producing intense H-ions inside a 9MeV cyclotron. The properties of the PIG ion source were simulated for a variety of electric field distributions and magnetic field strengths using CST Particle Studio. After analyzing 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 term of 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 KIRAMS-13 cyclotron by varying gas flow rate and arc current, respectively. The capacity of the designed ion source was also demonstrated by producing plasma inside the constructed 9MeV cyclotron. As a result, the ion source is verified to be capable to produce intense H- beam and high ion beam current for the desired 9 MeV cy...

  19. Electron Cloud Cyclotron Resonances in the Presence of a Short-bunch-length Relativistic Beam

    Energy Technology Data Exchange (ETDEWEB)

    Celata, C.M.; Furman, Miguel A.; Vay, J.-L.; Yu, Jennifer W.

    2008-09-02

    Computer simulations using the 2D code"POSINST" were used to study the formation of the electron cloud in the wiggler section of the positron damping ring of the International Linear Collider. In order to simulate an x-y slice of the wiggler (i.e., a slice perpendicular to the beam velocity), each simulation assumed a constant vertical magnetic field. At values of the magnetic field where the cyclotron frequency was an integral multiple of the bunch frequency, and where the field strength was less than approximately 0.6 T, equilibrium average electron densities were up to three times the density found at other neighboring field values. Effects of this resonance between the bunch and cyclotron frequency are expected to be non-negligible when the beam bunch length is much less than the product of the electron cyclotron period and the beam velocity, for a beam moving at v~;;c. Details of the dynamics of the resonance are described.

  20. Observation of quasi-periodic frequency sweeping in electron cyclotron emission of nonequilibrium mirror-confined plasma

    CERN Document Server

    Viktorov, M E; Mansfeld, D A; Golubev, S V

    2016-01-01

    Chirping frequency patterns have been observed in the electron cyclotron emission from strongly nonequilibrium plasma confined in a table-top mirror magnetic trap. Such patterns are typical for the formation of nonlinear phase space structures in a proximity of the wave-particle resonances of a kinetically unstable plasma, also known as the "holes and clumps" mechanism. Our data provides the first experimental evidence for acting of this mechanism in the electron cyclotron frequency domain.

  1. Millimeter-wave radiometer diagnostics of harmonic electron cyclotron emission in the Levitated Dipole Experiment.

    Science.gov (United States)

    Woskov, P P; Kesner, J; Garnier, D T; Mauel, M E

    2010-10-01

    A 110/137 GHz radiometer pair with collimated antenna pattern is being used to diagnose optically thin harmonic electron cyclotron emission from hot electrons in LDX. Signal levels of 0.1-1 keV and 110/137 ratios of 2-4 stationary with ECRH power have been observed. The large plasma core magnetic field gradient causes all relevant harmonics to be simultaneously viewed over a angle(k,B) angular range of 0°-90° representing a unique geometry for interpretation of ECE in terms of hot electron temperature and density.

  2. Dry cleaning of fluorocarbon residues by low-power electron cyclotron resonance hydrogen plasma

    CERN Document Server

    Lim, S H; Yuh, H K; Yoon Eui Joon; Lee, S I

    1988-01-01

    A low-power ( 50 W) electron cyclotron resonance hydrogen plasma cleaning process was demonstrated for the removal of fluorocarbon residue layers formed by reactive ion etching of silicon dioxide. The absence of residue layers was confirmed by in-situ reflection high energy electron diffraction and cross-sectional high resolution transmission electron microscopy. The ECR hydrogen plasma cleaning was applied to contact cleaning of a contact string structure, resulting in comparable contact resistance arising during by a conventional contact cleaning procedure. Ion-assisted chemical reaction involving reactive atomic hydrogen species generated in the plasma is attributed for the removal of fluorocarbon residue layers.

  3. Preliminary Analysis of the Hysteresis Phenomenon in Electron Cyclotron Resonance Plasma

    Institute of Scientific and Technical Information of China (English)

    LIU Ming-Hai; HU Xi-Wei; YU Guo-Yang; WU Qin-Chong; PAN Yuan

    2001-01-01

    The hysteresis phenomenon in electron cyclotron resonance plasma has been investigated theoretically by solvingthe equations of the density and energy balance of electrons and by taking the effects of several collisions suchas ionization and recombination into account. The results show that multiple steady states in experimentalmeasurements can be characterized by considering the fact that the energy balance function has three differentreal roots in certain regions of parameters. One root represents a saddle point and other roots represent stablepoints, that is, the system is bistable. The effects of ionization and the energy transformation due to the collisionsbetween the electron and neutral gas are also discussed.

  4. Electron acceleration at Jupiter: input from cyclotron-resonant interaction with whistler-mode chorus waves

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

    2013-10-01

    Full Text Available Jupiter has the most intense radiation belts of all the outer planets. It is not yet known how electrons can be accelerated to energies of 10 MeV or more. It has been suggested that cyclotron-resonant wave-particle interactions by chorus waves could accelerate electrons to a few MeV near the orbit of Io. Here we use the chorus wave intensities observed by the Galileo spacecraft to calculate the changes in electron flux as a result of pitch angle and energy diffusion. We show that, when the bandwidth of the waves and its variation with L are taken into account, pitch angle and energy diffusion due to chorus waves is a factor of 8 larger at L-shells greater than 10 than previously shown. We have used the latitudinal wave intensity profile from Galileo data to model the time evolution of the electron flux using the British Antarctic Survey Radiation Belt (BAS model. This profile confines intense chorus waves near the magnetic equator with a peak intensity at ∼5° latitude. Electron fluxes in the BAS model increase by an order of magnitude for energies around 3 MeV. Extending our results to L = 14 shows that cyclotron-resonant interactions with chorus waves are equally important for electron acceleration beyond L = 10. These results suggest that there is significant electron acceleration by cyclotron-resonant interactions at Jupiter contributing to the creation of Jupiter's radiation belts and also increasing the range of L-shells over which this mechanism should be considered.

  5. Efficient diffuse auroral electron scattering by electrostatic electron cyclotron harmonic waves in the outer magnetosphere

    Science.gov (United States)

    Ni, B.; Liang, J.; Thorne, R. M.; Angelopoulos, V.; Horne, R. B.; Kubyshkina, M.; Spanswick, E. L.; Donovan, E.; Lummerzheim, D.

    2011-12-01

    We report a causal connection between the intensification of electrostatic ECH waves and the postmidnight diffuse auroral activity in the absence of whistler-mode chorus waves at L = 11.5 on the basis of simultaneous observations from THEMIS spacecraft and NORSTAR optical instruments during 8 - 9 UT on February 5, 2009. We use the THEMIS particle and wave measurements together with the magnetically conjugate auroral observations for this event to illustrate an example where electrostatic electron cyclotron harmonic (ECH) waves are the main contributor to the diffuse auroral precipitation. We use the wave and particle data to perform a comprehensive theoretical and numerical analysis of ECH wave driven resonant scattering rates. We find that the observed ECH wave activity can cause intense pitch angle scattering of plasma sheet electrons between 100 eV and 5 keV at a rate of > 10-4 s-1 for equatorial pitch angles < 30°. The scattering approaches the strong diffusion limit in the realistic ambient magnetic field to produce efficient precipitation loss of < ~ 5 keV electrons on a timescale of a few hours or less. Using the electron differential energy flux inside the loss cone estimated based upon the energy-dependent efficiency of ECH wave scattering for an 8-second interval with high resolution wave data available, the auroral electron transport model developed by Lummerzheim [1987] produced an intensity of ~ 2.3 kR for the green-line diffuse aurora. Separately, Maxwellian fitting to the electron differential flux spectrum produced a green-line auroral intensity of ~ 2.6 kR. This is in good agreement with the ~2.4 kR green-line auroral intensity observed simultaneously at the magnetic footpoint (as inferred using the event-adaptive model of Kubyshkina et al. [2009, 2011]) of the location where the in situ observations were obtained. Our results support the scenario that enhanced ECH emissions in the central plasma sheet (CPS) can be an important or even dominant

  6. Magnet tests and status of the superconducting electron cyclotron resonance source SERSE

    Energy Technology Data Exchange (ETDEWEB)

    Ciavola, G.; Gammino, S.; Cafici, M.; Castro, M.; Chines, F.; Marletta, S. [INFN-Laboratorio Nazionale del Sud, Via S. Sofia 44, 95123 Catania (Italy); Alessandria, F. [INFN-LASA, Via F.lli Cervi 201, 20090 Segrate (Midway Islands) (Italy); Bourg, F.; Briand, P.; Melin, G.; Lagnier, R.; Seyfert, P. [CEA-Departement de Recherche Fondamentale sur la Matiere Condensee, Centre detudes Nucleaires de Grenoble, 38054 Grenoble Cedex 9 (France); Gaggero, G.; Losasso, M.; Penco, R. [ANSALDO-GIE, Via N. Lorenzi 8, 16152 Genova (Italy)

    1996-03-01

    At Laboratorio Nazionale del Sud a superconducting 14.5 GHz electron cyclotron resonance (ECR) source will be used as injector for the K-800 superconducting cyclotron. The original project of its magnetic system has been upgraded by taking into account the results of the high B mode operation of the 6.4 GHz SC-ECRIS at MSU-NSCL and now the mirror field may achieve 2.7 T, which is much higher than the confining field of any other ECR source. The magnet design will allow us to operate in a wide range of magnetic configurations making it easy to tune the source. The status of the project will be outlined and the preliminary results of the tests of the superconducting magnets will be described. A brief description of the tests to be carried out on the source during the first period of operation on the test bench in Grenoble follows. {copyright} {ital 1996 American Institute of Physics.}

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

    Science.gov (United States)

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

    2015-02-01

    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 Bmin-field in single frequency heating mode is often ≤0.8BECR, 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O., E-mail: olli.tarvainen@jyu.fi; Laulainen, J.; Komppula, J.; Kronholm, R.; Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyväskylä, 40500 Jyväskylä (Finland); Izotov, I.; Mansfeld, D. [Institute of Applied Physics, RAS, 46 Ul‘yanova St., 603950 Nizhny Novgorod (Russian Federation); Skalyga, V. [Institute of Applied Physics, RAS, 46 Ul‘yanova St., 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., 603950 Nizhny Novgorod (Russian Federation)

    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.

  9. Strong Coupling of the Cyclotron Motion of Surface Electrons on Liquid Helium to a Microwave Cavity

    Science.gov (United States)

    Abdurakhimov, L. V.; Yamashiro, R.; Badrutdinov, A. O.; Konstantinov, D.

    2016-07-01

    The strong coupling regime is observed in a system of two-dimensional electrons whose cyclotron motion is coupled to an electromagnetic mode in a Fabry-Perot cavity resonator. Rabi splitting of eigenfrequencies of the coupled motion is observed both in the cavity reflection spectrum and ac current of the electrons, the latter probed by measuring their bolometric photoresponse. Despite the fact that similar observations of Rabi splitting in many-particle systems have been described as a quantum-mechanical effect, we show that the observed splitting can be explained completely by a model based on classical electrodynamics.

  10. Highly charged ion X-rays from Electron-Cyclotron Resonance Ion Sources

    OpenAIRE

    Indelicato, Paul; Boucard, S.; Covita, D. S.; Gotta, D.; Gruber, A; Hirtl, A.; Fuhrmann, H.; Le Bigot, E.-O.; Schlesser, S.; dos Santos, J. M. F.; Simons, L.M.; Stingelin, L.; Trassinelli, Martino; Veloso, J.; Wasser, A.

    2006-01-01

    Radiation from the highly-charged ions contained in the plasma of Electron-Cyclotron Resonance Ion Sources constitutes a very bright source of X-rays. Because the ions have a relatively low kinetic energy ($\\approx 1$~eV) transitions can be very narrow, containing only small Doppler broadening. We describe preliminary accurate measurements of two and three-electron ions with $Z=16$--18. We show how these measurement can test sensitively many-body relativistic calculations or can be used as X-...

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

    Energy Technology Data Exchange (ETDEWEB)

    Asaji, T., E-mail: asaji@oshima-k.ac.jp; Hirabara, N.; Izumihara, T.; Nakamizu, T.; Ohba, T.; Nakamura, T.; Furuse, M. [Oshima National College of Maritime Technology (OCMT), 1091-1 Komatsu, Suo-oshima, Yamaguchi 742-2193 (Japan); Hitobo, T. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama 930-1305 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    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.

  12. Dual array 3D electron cyclotron emission imaging at ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Classen, I. G. J., E-mail: I.G.J.Classen@differ.nl; Bogomolov, A. V. [FOM-Institute DIFFER, Dutch Institute for Fundamental Energy Research, 3430 BE Nieuwegein (Netherlands); Domier, C. W.; Luhmann, N. C. [Department of Applied Science, University of California at Davis, Davis, California 95616 (United States); Suttrop, W.; Boom, J. E. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Tobias, B. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Donné, A. J. H. [FOM-Institute DIFFER, Dutch Institute for Fundamental Energy Research, 3430 BE Nieuwegein (Netherlands); Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

    2014-11-15

    In a major upgrade, the (2D) electron cyclotron emission imaging diagnostic (ECEI) at ASDEX Upgrade has been equipped with a second detector array, observing a different toroidal position in the plasma, to enable quasi-3D measurements of the electron temperature. The new system will measure a total of 288 channels, in two 2D arrays, toroidally separated by 40 cm. The two detector arrays observe the plasma through the same vacuum window, both under a slight toroidal angle. The majority of the field lines are observed by both arrays simultaneously, thereby enabling a direct measurement of the 3D properties of plasma instabilities like edge localized mode filaments.

  13. Fast Ion Induced Shearing of 2D Alfven Eigenmodes Measured by Electron Cyclotron Emission Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, Ben [University of California, Davis; Classen, I.G.J. [FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands; Domier, C. W. [University of California, Davis; Heidbrink, W. [University of California, Irvine; Luhmann, N.C. [University of California, Davis; Nazikian, Raffi [Princeton Plasma Physics Laboratory (PPPL); Park, H.K. [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Spong, Donald A [ORNL; Van Zeeland, Michael [General Atomics

    2011-01-01

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfven eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the observations are found to be in excellent agreement with simulations using an ideal MHD code (NOVA), other characteristics distinctly reveal the influence of fast ions on the mode structures. These features are found to be well described by the nonperturbative hybrid MHD-gyrofluid model TAEFL.

  14. Production of electron cyclotron resonance plasma by using multifrequencies microwaves and active beam profile control on a large bore electron cyclotron resonance ion source with permanent magnets.

    Science.gov (United States)

    Kato, Yushi; Watanabe, Takeyoshi; Matsui, Yuuki; Hirai, Yoshiaki; Kutsumi, Osamu; Sakamoto, Naoki; Sato, Fuminobu; Iida, Toshiyuki

    2010-02-01

    A new concept on magnetic field with all magnets on plasma production and confinement has been proposed to enhance efficiency of an electron cyclotron resonance (ECR) plasma for broad and dense ion beam source under the low pressure. The magnetic field configuration is constructed by a pair of magnets assembly, i.e., comb-shaped magnet which cylindrically surrounds the plasma chamber. The resonance zones corresponding to the fundamental ECR for 2.45 GHz and 11-13 GHz frequencies are constructed at different positions. The profiles of the plasma parameters in the ECR ion source are different from each frequency of microwave. Large bore extractor is set at the opposite side against the microwave feeds. It is found that differences of their profiles also appear at those of ion beam profiles. We conducted to launch simultaneously multiplex frequencies microwaves controlled individually, and tried to control the profiles of the plasma parameters and then those of extracted ion beam.

  15. Stochastic heating in the cyclotron resonance of electrons; Calentamiento estocastico en la resonancia ciclotronica de los electrones

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Hernandez A, O. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    The study of the different schemes of plasma heating by radiofrequency waves is a very actual problem related with the plasma heating in different machines and the particle acceleration mechanisms. In this work, it is obtained the expression for the temporal evolution of the energy absorbed in the cyclotron resonance of electrons where it is showed the stochastic character of the energy absorption. It is obtained the stochastic criteria in a magnetic configuration of an Ecr type plasma source. (Author)

  16. Benchmarking of electron cyclotron heating and current drive codes on ITER scenarios within the European Integrated Tokamak Modelling framework

    Directory of Open Access Journals (Sweden)

    Peysson Y.

    2012-09-01

    Full Text Available Electron cyclotron resonance heating (ECRH and electron cyclotron current drive (ECCD are used to heat the plasma, to tailor the current profiles and to achieve different operating regimes of tokamak plasmas. Plasmas with ECRH/ECCD are characterized by non-thermal electrons, which cannot be described by a Maxwellian distribution. Non-thermal electrons are also generated during MHD activity, like sawteeth crashes. Quantifying the non-thermal electron distribution is therefore a key for understanding EC heated fusion plasmas. For this purpose a vertical electron cyclotron emission (V-ECE diagnostic is being installed at TCV. The diagnostic layout, the calibration, the analysis technique for data interpretation, the physics potentials and limitations are discussed.

  17. Electron pitch angle diffusion by electrostatic electron cyclotron harmonic waves: The origin of pancake distributions

    Science.gov (United States)

    Horne, Richard B.; Thorne, Richard M.

    2000-03-01

    It has been suggested that highly anisotropic electron pancake distributions are the result of pitch angle diffusion by electrostatic electron cyclotron harmonic (ECH) and whistler mode waves in the equatorial region. Here we present pitch angle diffusion rates for ECH wave spectra centered at different frequencies with respect to the electron gyrofrequency Ωe corresponding to spacecraft observations. The wave spectra are carefully mapped to the correct resonant electron velocities. We show that previous diffusion calculations of ECH waves at 1.5Ωe, driven by the loss cone instability, result in large diffusion rates confined to a small range of pitch angles near the loss cone and therefore cannot account for pancake distributions. However, when the wave spectrum is centered at higher frequencies in the band (>1.6Ωe), the diffusion rates become very small inside the loss cone, peak just outside, and remain large over a wide range of pitch angles up to 60° or more. When the upper hybrid resonance frequency ωUHR is several times Ωe, ECH waves excited in higher bands also contribute significantly to pitch angle diffusion outside the loss cone up to very large pitch angles. We suggest that ECH waves driven by a loss cone could form pancake distributions as they grow if the wave spectrum extends from the middle to the upper part of the first (and higher) gyroharmonic bands. Alternatively, we suggest that pancake distributions can be formed by outward propagation in a nonhomogeneous medium, so that resonant absorption occurs at higher frequencies between(n+12) and (n+1)Ωe in regions where waves are also growing locally at <=1.5Ωe. The calculated diffusion rates suggest that ECH waves with amplitudes of the order of 1 mV m-1 can form pancake distributions from an initially isotropic distribution on a timescale of a few hours. This is consistent with recent CRRES observations of ECH wave amplitudes following substorm injections near geostationary orbit and the

  18. Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities.

    Science.gov (United States)

    Choi, M J; Park, H K; Yun, G S; Nam, Y B; Choe, G H; Lee, W; Jardin, S

    2016-01-01

    The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (Te) fluctuations by measuring the ECE intensity IECE ∝ Te in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat Te assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (Te,rel) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

  19. Mitigation of energetic electrons in the magnetosphere by amplified whistler wave under double cyclotron resonances

    Science.gov (United States)

    Kuo, S. P.

    2008-10-01

    An optimal approach reducing the population of MeV electrons in the magnetosphere is presented. Under a double resonance condition, whistler wave is simultaneously in cyclotron resonance with keV and MeV electrons. The injected whistler waves is first amplified by the background keV electrons via loss-cone negative mass instability to become effective in precipitating MeV electrons via cyclotron resonance elevated chaotic scattering. The numerical results show that a small amplitude whistler wave can be amplified by more than 25 dB. The amplification factor reduces only about 10 dB with a 30 dB increase of the initial wave intensity. Use of an amplified whistler wave to scatter 1.5 MeV electrons from an initial pitch angle of 86.5°to a pitch angle <50° is demonstrated. The ratio of the required wave magnetic field to the background magnetic field is calculated to be about 8×10-4.

  20. The electron-cyclotron maser instability as a source of plasma radiation. [Solar radio bursts

    Science.gov (United States)

    Winglee, R. M.; Dulk, G. A.

    1986-01-01

    The generation of continuum bursts from the sun at dm and m wavelengths (in particular, type IV bursts) via the electron-cyclotron-maser instability is examined. The maser instability can be driven by an electron distribution with either a loss-cone anisotropy or a peak at large pitch angles. For omega(p)/Omega(e) much greater than 1, the maser emission is produced by electrons interacting through a harmonic (cyclotron) resonance and is electrostatic, being in the upper hybrid mode at frequencies approximately equal to omega(p). Coalescence processes are required to convert the electrostatic waves into transverse radiation which can escape from the source region. Whether the resultant spectrum is nearly a smooth continuum or has a zebra-stripe pattern (both of which occur in type IV bursts) depends on the form of the electron distribution, inhomogeneities in the density and magnetic field, and whether the maser reaches saturation. For at least the case of some type IV dm bursts with fine structure, comparison with observations seems to indicate that the electrons producing the emission are more likely to have a loss-cone distribution, and that the maser instability is not at saturation.

  1. Development of electron cyclotron emission imaging system on the HL-2A tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M.; Shi, Z. B.; Liu, Z. T.; Ding, X. T.; Li, J.; Zhong, W. L.; Chen, W.; Che, Y. L.; Fu, B. Z.; Cui, Z. Y.; Sun, P.; Liu, Y.; Yang, Q. W.; Duan, X. R. [Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041 (China); Che, S.; Domier, C. W.; Luhmann, N. C. Jr.; Hu, X.; Spear, A. [Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616 (United States)

    2013-11-15

    A 2D electron cyclotron emission imaging (ECEI) system has been developed for measurement of electron temperature fluctuations in the HL-2A tokamak. It is comprised of a front-end 24 channel heterodyne imaging array with a tunable RF range spanning 75–110 GHz, and a set of back-end ECEI electronics that together generate 24 × 8 = 192 channel images of the 2nd harmonic X-mode electron cyclotron emission from the HL-2A plasma. The simulated performance of the local oscillator (LO) optics and radio frequency (RF) optics is presented, together with the laboratory characterization results. The Gaussian beams from the LO optics are observed to properly cover the entire detector array. The ECE signals from the plasma are mixed with the LO signal in the array box, then delivered to the electronics system by low-loss microwave cables, and finally to the digitizers. The ECEI system can achieve temporal resolutions of ∼μs, and spatial resolutions of 1 cm (radially) and 2 cm (poloidally)

  2. Microwave power coupling with electron cyclotron resonance plasma using Langmuir probe

    Indian Academy of Sciences (India)

    S K Jain; V K Senecha; P A Naik; P R Hannurkar; S C Joshi

    2013-07-01

    Electron cyclotron resonance (ECR) plasma was produced at 2.45 GHz using 200 – 750 W microwave power. The plasma was produced from argon gas at a pressure of 2 × 10−4 mbar. Three water-cooled solenoid coils were used to satisfy the ECR resonant conditions inside the plasma chamber. The basic parameters of plasma, such as electron density, electron temperature, floating potential, and plasma potential, were evaluated using the current–voltage curve using a Langmuir probe. The effect of microwave power coupling to the plasma was studied by varying the microwave power. It was observed that the optimum coupling to the plasma was obtained for ∼ 600 W microwave power with an average electron density of ∼ 6 × 1011 cm−3 and average electron temperature of ∼ 9 eV.

  3. Instability of field-aligned electron-cyclotron waves in a magnetic mirror plasma with anisotropic temperature

    Science.gov (United States)

    Grishanov, N. I.; Azarenkov, N. A.

    2016-08-01

    > Dispersion characteristics have been analysed for field-aligned electron-cyclotron waves (also known as right-hand polarized waves, extraordinary waves or whistlers) in a cylindrical magnetic mirror plasma including electrons with anisotropic temperature. It is shown that the instability of these waves is possible only in the range below the minimal electron-cyclotron frequency, which is much lower than the gyrotron frequency used for electron-cyclotron resonance power input into the plasma, under the condition where the perpendicular temperature of the resonant electrons is larger than their parallel temperature. The growth rates of whistler instability in the two magnetized plasma models, where the stationary magnetic field is either uniform or has a non-uniform magnetic mirror configuration, are compared.

  4. Major results of the electron cyclotron heating experiment in the PDX tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Hsuan, H.; Bol, K.; Bowen, N.; Boyd, D.; Cavallo, A.; Dimits, A.; Doane, J.; Elder, G.; Goldman, M.; Grek, B.

    1984-07-01

    Electron Cyclotron Heating (ECH) experiments on PDX have been carried out with two 60 GHz pulsed gyrotrons each yielding up to approximately 100 kW. The ECH system used two waveguide runs each about 30 meters long. One run included 5 bends and the other, 7 bends. Predetermined waveguide modes were transmitted. The electron cyclotron waves were launched in narrow beams from both the high field and the low field sides of the plasma torus. The major new physics results are: (1) efficient central electron heating for both ohmic and neutral beam heated target plasmas; (2) alteration of MHD behavior using ECH; (3) identification of the trapped electron population with ECH; and (4) signature of velocity-space time evolution during ECH. In the best heating results obtained, Thomson scattering data indicated a central temperature increase from less than or equal to 1.5 keV to greater than or equal to 2.5 keV. This occurred with an average density of about 10/sup 13/ cm/sup -3/ and approximately 80 kW outside-launch ordinary-mode heating.

  5. Numerical Simulations of Nonlinear Dynamics of Electron Cyclotron Maser with a Straight Beam

    Institute of Scientific and Technical Information of China (English)

    KONG Ling-Bao; HOU Zhi-Ling

    2011-01-01

    An electron cyclotron maser based on anomalous Doppler effect (ADECM) with an initially axial beam velocity is considered,and the nonlinear equation of beam-wave interaction is presented.With the numerical methods,the nonlinear dynamics of the ADECM is investigated.It is shown that the saturated interaction efficiency of the ADECM approaches 90% and the interaction length for the saturated efficiency spans about 5-20cm.The results may be of importance for designing a compact device in applications in microwave generations or microwave heating of ceramic laminates.In the late 1950s,the theoretical studies on the instability of electron cyclotron maser based on normal Doppler effect (NDECM) were performed almost simultaneously by Gaponov,[1] Twiss,[2] and Schneider.[3] Their discoveries have resulted in the most successful fast-wave devices such as the gyrotron and variants.[4,5] The possible applications of microwaves span a wide range of technologies such as in thermonuclear fusion energy,charged particle accelerations,radar systems,and processing of advanced ceramics.[6-16]%An electron cyclotron maser based on anomalous Doppler effect (ADECM) with an initially axial beam velocity is considered, and the nonlinear equation of beam-wave interaction is presented. With the numerical methods, the nonlinear dynamics of the ADECM is investigated. It is shown that the saturated interaction efficiency of the ADECM approaches 90% and the interaction length for the saturated efficiency spans about 5-20 cm. The results may be of importance for designing a compact device in applications in microwave generations or microwave heating of ceramic laminates.

  6. Diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves

    Science.gov (United States)

    Tripathi, A. K.; Singhal, R. P.

    2009-11-01

    Pitch-angle diffusion coefficients have been calculated for resonant interaction with electrostatic electron cyclotron harmonic (ECH) waves using quasilinear diffusion theory. Unlike previous calculations, the parallel group velocity has been included in this study. Further, ECH wave intensity is expressed as a function of wave frequency and wave normal angle with respect to ambient magnetic field. It is found that observed wave electric field amplitudes in Earth's magnetosphere are sufficient to set electrons on strong diffusion in the energy ranges of a few hundred eV. However, the required amplitudes are larger than the observed values for keV electrons and higher by about a factor of 3 compared to past calculations. Required electric field amplitudes are smaller at larger radial distances. It is concluded that ECH waves are responsible for diffuse auroral precipitation of electrons with energies less than about 500 eV.

  7. H- extraction from electron-cyclotron-resonance-driven multicusp volume source operated in pulsed mode

    Science.gov (United States)

    Svarnas, P.; Bacal, M.; Auvray, P.; Béchu, S.; Pelletier, J.

    2006-03-01

    H2 microwave (2.45GHz) pulsed plasma is produced from seven elementary electron cyclotron resonance sources installed into the magnetic multipole chamber "Camembert III" (École Polytechnique—Palaiseau) from which H- extraction takes place. The negative-ion and electron extracted currents are studied through electrical measurements and the plasma parameters by means of electrostatic probe under various experimental conditions. The role of the plasma electrode bias and the discharge duty cycle in the extraction process is emphasized. The gas breakdown at the beginning of every pulse gives rise to variations of the plasma characteristic parameters in comparison with those established at the later time of the pulse, where the electron temperature, the plasma potential, and the floating potential converge to the values obtained for a continuous plasma. The electron density is significantly enhanced in the pulsed mode.

  8. Physics design of the in-vessel collection optics for the ITER electron cyclotron emission diagnostic

    Science.gov (United States)

    Rowan, W. L.; Houshmandyar, S.; Phillips, P. E.; Austin, M. E.; Beno, J. H.; Hubbard, A. E.; Khodak, A.; Ouroua, A.; Taylor, G.

    2016-11-01

    Measurement of the electron cyclotron emission (ECE) is one of the primary diagnostics for electron temperature in ITER. In-vessel, in-vacuum, and quasi-optical antennas capture sufficient ECE to achieve large signal to noise with microsecond temporal resolution and high spatial resolution while maintaining polarization fidelity. Two similar systems are required. One views the plasma radially. The other is an oblique view. Both views can be used to measure the electron temperature, while the oblique is also sensitive to non-thermal distortion in the bulk electron distribution. The in-vacuum optics for both systems are subject to degradation as they have a direct view of the ITER plasma and will not be accessible for cleaning or replacement for extended periods. Blackbody radiation sources are provided for in situ calibration.

  9. Physics design of the in-vessel collection optics for the ITER electron cyclotron emission diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Rowan, W. L., E-mail: w.l.rowan@austin.utexas.edu; Houshmandyar, S.; Phillips, P. E.; Austin, M. E. [Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States); Beno, J. H.; Ouroua, A. [Center for Electromechanics, The University of Texas at Austin, Austin, Texas 78712 (United States); Hubbard, A. E. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States); Khodak, A.; Taylor, G. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-11-15

    Measurement of the electron cyclotron emission (ECE) is one of the primary diagnostics for electron temperature in ITER. In-vessel, in-vacuum, and quasi-optical antennas capture sufficient ECE to achieve large signal to noise with microsecond temporal resolution and high spatial resolution while maintaining polarization fidelity. Two similar systems are required. One views the plasma radially. The other is an oblique view. Both views can be used to measure the electron temperature, while the oblique is also sensitive to non-thermal distortion in the bulk electron distribution. The in-vacuum optics for both systems are subject to degradation as they have a direct view of the ITER plasma and will not be accessible for cleaning or replacement for extended periods. Blackbody radiation sources are provided for in situ calibration.

  10. Multicusp type machine for electron cyclotron resonance plasma with reduced dimensions

    Science.gov (United States)

    Amemiya, H.; Maeda, M.

    1996-03-01

    Plasmas are created in a cusp type magnetic trap using electron cyclotron resonance heating. The magnetic field is generated with permanent magnets forming a 12-pole, whereby the polarity at the ends of the rods has been reversed in order to obtain end plugs and to improve the plasma confinement. In this way, the plasma volume could be reduced such that the cross section was close to or smaller than the cutoff width of a circular waveguide. This increases the microwave power absorbed and gives a high plasma density even above the cutoff value.

  11. Multicusp type machine for electron cyclotron resonance plasma with reduced dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Amemiya, H.; Maeda, M. [The Institute of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako-shi, Saitama-Pref., 351-01 (Japan)

    1996-03-01

    Plasmas are created in a cusp type magnetic trap using electron cyclotron resonance heating. The magnetic field is generated with permanent magnets forming a 12-pole, whereby the polarity at the ends of the rods has been reversed in order to obtain end plugs and to improve the plasma confinement. In this way, the plasma volume could be reduced such that the cross section was close to or smaller than the cutoff width of a circular waveguide. This increases the microwave power absorbed and gives a high plasma density even above the cutoff value. {copyright} {ital 1996 American Institute of Physics.}

  12. A preliminary study of the electron cyclotron resonance ion source for the RAON injector

    Science.gov (United States)

    Hong, I. S.; Kim, Y.; Choi, S. J.; Heo, J. I.; Jin, H. C.; Park, B. S.

    2016-09-01

    We have built and tested an electron cyclotron resonance (ECR) ion source for the Rare Isotope Accelerator of Newness (RAON) injector. Fully superconducting magnets were developed for the ECR ion source. First, an oxygen plasma was ignited, and a preliminary highly-charged oxygen beam was extracted. Next, a 100 μA beam current of oxygen 5+ was extracted when a 1 kW microwave power was injected using a 28 GHz gyrotron. Finally, an off-site test facility was proposed to test the components of the injector by using heavy-ion beams generated by the ECR ion source.

  13. Destabilization of fast particle stabilized sawteeth in ASDEX Upgrade with electron cyclotron current drive

    DEFF Research Database (Denmark)

    Igochine, V.; Chapman, I.T.; Bobkov, V.

    2011-01-01

    It is often observed that large sawteeth trigger the neoclassical tearing mode well below the usual threshold for this instability. At the same time, fast particles in the plasma core stabilize sawteeth and provide these large crashes. The paper presents results of first experiments in ASDEX...... Upgrade for destabilization of fast particle stabilized sawteeth with electron cyclotron current drive (ECCD). It is shown that moderate ECCD from a single gyrotron is able to destabilize the fast particle stabilized sawteeth. A reduction in sawtooth period by about 40% was achieved in first experiments...

  14. Scattering of diffracting beams of electron cyclotron waves by random density fluctuations in inhomogeneous plasmas

    Science.gov (United States)

    Weber, Hannes; Maj, Omar; Poli, Emanuele

    2015-03-01

    The physics and first results of the new WKBeam code for electron cyclotron beams in tokamak plasmas are presented. This code is developed on the basis of a kinetic radiative transfer model which is general enough to account for the effects of diffraction and density fluctuations on the beam. Our preliminary numerical results show a significant broadening of the power deposition profile in ITER due to scattering from random density fluctuations at the plasma edge, while such scattering effects are found to be negligible in medium-size tokamaks like ASDEX upgrade.

  15. Bio-Nano ECRIS: an electron cyclotron resonance ion source for new materials production.

    Science.gov (United States)

    Uchida, T; Minezaki, H; Tanaka, K; Muramatsu, M; Asaji, T; Kato, Y; Kitagawa, A; Biri, S; Yoshida, Y

    2010-02-01

    We developed an electron cyclotron resonance ion source (ECRIS) for new materials production on nanoscale. Our main target is the endohedral fullerenes, which have potential in medical care, biotechnology, and nanotechnology. In particular, iron-encapsulated fullerene can be applied as a contrast material for magnetic resonance imaging or microwave heat therapy. Thus, our new ECRIS is named the Bio-Nano ECRIS. In this article, the recent progress of the development of the Bio-Nano ECRIS is reported: (i) iron ion beam production using induction heating oven and (ii) optimization of singly charged C(60) ion beam production.

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

    Science.gov (United States)

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

    2014-02-01

    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 C60 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Minezaki, H.; Ishihara, S. [Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan); Muramatsu, M.; Kitagawa, A.; Drentje, A. G. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen (Hungary); Asaji, T. [Oshima National College of Maritime Technology, Yamaguchi 742-2193 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Engineering, Toyo University, Kawagoe 350-8585 (Japan)

    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.

  18. Time resolved measurements of the biased disk effect at an Electron Cyclotron Resonance Ion Source

    Directory of Open Access Journals (Sweden)

    K. E. Stiebing

    1999-12-01

    Full Text Available First results are reported from time resolved measurements of ion currents extracted from the Frankfurt 14 GHz Electron Cyclotron Resonance Ion Source with pulsed biased-disk voltage. It was found that the ion currents react promptly to changes of the bias. From the experimental results it is concluded that the biased disk effect is mainly due to improvements of the extraction conditions for the source and/or an enhanced transport of ions into the extraction area. By pulsing the disk voltage, short current pulses of highly charged ions can be generated with amplitudes significantly higher than the currents obtained in continuous mode.

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

    Science.gov (United States)

    Lu, W; Xie, D Z; Zhang, X Z; Xiong, B; Ruan, L; Sha, S; Zhang, W H; Cao, Y; Lin, S H; Guo, J W; Fang, X; Guo, X H; Li, X X; Ma, H Y; Yang, Y; Wu, Q; Zhao, H Y; Ma, B H; Wang, H; Zhu, Y H; Feng, Y C; Li, J Y; Li, J Q; Sun, L T; Zhao, H W

    2012-02-01

    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.

  20. Remote-Steering Antennas for 140 GHz Electron Cyclotron Heating of the Stellarator W7-X

    Directory of Open Access Journals (Sweden)

    Lechte C.

    2017-01-01

    Full Text Available For electron cyclotron resonance heating of the stellarator W7-X at IPP Greifswald, a 140 GHz/10 MW cw millimeter wave system has been built. Two out of 12 launchers will employ a remote-steering design. This paper describes the overall design of the two launchers, and design issues like input coupling structures, manufacturing of corrugated waveguides, optimization of the steering range, integration of vacuum windows, mitrebends and vacuum valves into the launchers, as well as low power tests of the finished waveguides.

  1. Note: Upgrade of electron cyclotron emission imaging system and preliminary results on HL-2A tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M., E-mail: jiangm@swip.ac.cn; Shi, Z. B.; Zhong, W. L.; Chen, W.; Liu, Z. T.; Ding, X. T.; Yang, Q. W.; Zhang, B. Y.; Shi, P. W.; Liu, Y.; Fu, B. Z.; Xu, Y. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Domier, C. W.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Yang, Z. C. [School of Physics and Chemistry, Xihua University, Chengdu 610039 (China)

    2015-07-15

    The electron cyclotron emission imaging system on the HL-2A tokamak has been upgraded to 24 (poloidally) × 16 (radially) channels based on the previous 24 × 8 array. The measurement region can be flexibly shifted due to the independence of the two local oscillator sources, and the field of view can be adjusted easily by changing the position of the zoom lenses. The temporal resolution is about 2.5 μs and the achievable spatial resolution is 1 cm. After laboratory calibration, it was installed on HL-2A tokamak in 2014, and the local 2D mode structures of MHD activities were obtained for the first time.

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

    CERN Document Server

    Asaji, T; Uchida, T; Minezaki, H; Ishihara, S; Racz, R; Muramatsu, M; Biri, S; Kitagawa, A; Kato, Y; Yoshida, Y

    2015-01-01

    A synthesis technology of endohedral fullerenes such as Fe@C60 has developed with an electron cyclotron resonance (ECR) ion source. The production of N@C60 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Higurashi, Y.; Ohnishi, J.; Nakagawa, T.; Haba, H.; Fujimaki, M.; Komiyama, M.; Kamigaito, O. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Tamura, M.; Aihara, T.; Uchiyama, A. [SHI Accelerator Service Ltd., 1-17-6 Osaki, Shinagawa, Tokyo 141-0032 (Japan)

    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.

  4. Low-noise heterodyne receiver for electron cyclotron emission imaging and microwave imaging reflectometry

    Science.gov (United States)

    Tobias, B.; Domier, C. W.; Luhmann, N. C.; Luo, C.; Mamidanna, M.; Phan, T.; Pham, A.-V.; Wang, Y.

    2016-11-01

    The critical component enabling electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry (MIR) to resolve 2D and 3D electron temperature and density perturbations is the heterodyne imaging array that collects and downconverts radiated emission and/or reflected signals (50-150 GHz) to an intermediate frequency (IF) band (e.g. 0.1-18 GHz) that can be transmitted by a shielded coaxial cable for further filtering and detection. New circuitry has been developed for this task, integrating gallium arsenide (GaAs) monolithic microwave integrated circuits (MMICs) mounted on a liquid crystal polymer (LCP) substrate. The improved topology significantly increases electromagnetic shielding from out-of-band interference, leads to 10× improvement in the signal-to-noise ratio, and dramatic cost savings through integration. The current design, optimized for reflectometry and edge radiometry on mid-sized tokamaks, has demonstrated >20 dB conversion gain in upper V-band (60-75 GHz). Implementation of the circuit in a multi-channel electron cyclotron emission imaging (ECEI) array will improve the diagnosis of edge-localized modes and fluctuations of the high-confinement, or H-mode, pedestal.

  5. Nonlinear electron acoustic cyclotron waves in presence of uniform magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Manjistha; Khan, Manoranjan [Department of Instrumentation Science, Jadavpur University, Kolkata 700 032 (India); Ghosh, Samiran [Department of Applied Mathematics, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Roychoudhury, Rajkumar [Indian Statistical Institute, Kolkata 700 108 (India); Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2013-04-15

    Nonlinear electron acoustic cyclotron waves (EACW) are studied in a quasineutral plasma in presence of uniform magnetic field. The fluid model is used to describe the dynamics of two temperature electron species in a stationary charge neutral inhomogeneous background. In long wavelength limit, it is shown that the linear electron acoustic wave is modified by the uniform magnetic field similar to that of electrostatic ion cyclotron wave. Nonlinear equations for these waves are solved by using Lagrangian variables. Results show that the spatial solitary wave-like structures are formed due to nonlinearities and dispersions. These structures transiently grow to larger amplitude unless dispersive effect is actively operative and able to arrest this growth. We have found that the wave dispersion originated from the equilibrium inhomogeneity through collective effect and is responsible for spatiotemporal structures. Weak dispersion is not able to stop the wave collapse and singular structures of EACW are formed. Relevance of the results in the context of laboratory and space plasmas is discussed.

  6. Ultrathin oxide grown on polysilicon by using an electron cyclotron resonance N sub 2 O plasma

    CERN Document Server

    Han, S Y

    2000-01-01

    We have developed a process for growing ultrathin oxide on a polysilicon layer by using an electron cyclotron resonance (ECR) N sub 2 O plasma. Sub-4-nm thick polyoxides were grown on n sup + and p sup + polysilicon layers and were characterized. These oxides had larger breakdown fields, smaller electron trapping characteristics, and larger Q sub B sub D values than those of thermal polyoxides. The electron trapping characteristics of ECR N sub 2 O plasma polyoxides, which were smaller than those of thermal polyoxides at positive bias, resulted from the smaller roughness of the polysilicon surface after the oxidation process. Under a negative constant-current stress of 20 mA/cm sup 2 for polyoxide on p sup + polysilicon were obtained. These ultrathin plasma polyoxides would be good candidates for future inter-poly dielectrics and gate oxides for thin film transistors.

  7. Cyclotron waves in plasma

    CERN Document Server

    Lominadze, D G

    2013-01-01

    Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

  8. Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

    CERN Document Server

    Schwarm, F -W; Falkner, S; Pottschmidt, K; Wolff, M T; Becker, P A; Sokolova-Lapa, E; Klochkov, D; Ferrigno, C; Fuerst, F; Hemphill, P B; Marcu-Cheatham, D M; Dauser, T; Wilms, J

    2016-01-01

    Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron...

  9. Enhanced Physicochemical and Biological Properties of Ion-Implanted Titanium Using Electron Cyclotron Resonance Ion Sources

    Directory of Open Access Journals (Sweden)

    Csaba Hegedűs

    2016-01-01

    Full Text Available The surface properties of metallic implants play an important role in their clinical success. Improving upon the inherent shortcomings of Ti implants, such as poor bioactivity, is imperative for achieving clinical use. In this study, we have developed a Ti implant modified with Ca or dual Ca + Si ions on the surface using an electron cyclotron resonance ion source (ECRIS. The physicochemical and biological properties of ion-implanted Ti surfaces were analyzed using various analytical techniques, such as surface analyses, potentiodynamic polarization and cell culture. Experimental results indicated that a rough morphology was observed on the Ti substrate surface modified by ECRIS plasma ions. The in vitro electrochemical measurement results also indicated that the Ca + Si ion-implanted surface had a more beneficial and desired behavior than the pristine Ti substrate. Compared to the pristine Ti substrate, all ion-implanted samples had a lower hemolysis ratio. MG63 cells cultured on the high Ca and dual Ca + Si ion-implanted surfaces revealed significantly greater cell viability in comparison to the pristine Ti substrate. In conclusion, surface modification by electron cyclotron resonance Ca and Si ion sources could be an effective method for Ti implants.

  10. Theoretical study of electromagnetic electron cyclotron waves in the presence of AC field in Uranian magnetosphere

    Science.gov (United States)

    Pandey, R. S.; Kaur, Rajbir

    2015-10-01

    Electromagnetic electron cyclotron (EMEC) waves with temperature anisotropy in the magnetosphere of Uranus have been studied in present work. EMEC waves are investigated using method of characteristic solution by kinetic approach, in presence of AC field. In 1986, Voyager 2 encounter with Uranus revealed that magnetosphere of Uranus exhibit non-Maxwellian high-energy tail distribution. So, the dispersion relation, real frequency and growth rate are evaluated using Lorentzian Kappa distribution function. Effect of temperature anisotropy, AC frequency and number density of particles is found. The study is also extended to oblique propagation of EMEC waves in presence and absence of AC field. Through comprehensive mathematical analysis it is found that when EMEC wave propagates parallel to intrinsic magnetic field of Uranus, its growth is more enhanced than in case of oblique propagation. Results are also discussed in context to magnetosphere of Earth and also gives theoretical explanation to existence of high energetic particles observed by Voyager 2 in the magnetosphere of Uranus. The results can present a further insight into the nature of electron-cyclotron instability condition for the whistler mode waves in the outer radiation belts of Uranus or other space plasmas.

  11. User requirements and conceptual design of the ITER Electron Cyclotron Control System

    Energy Technology Data Exchange (ETDEWEB)

    Carannante, Giuseppe, E-mail: Giuseppe.Carannante@F4E.europa.eu [Fusion for Energy, Josep Pla 2, Barcelona 08019 (Spain); Cavinato, Mario [Fusion for Energy, Josep Pla 2, Barcelona 08019 (Spain); Gandini, Franco [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Granucci, Gustavo [Istituto di Fisica del Plasma ENEA-CNR-EURATOM, via Cozzi 53, 20125 Milano (Italy); Henderson, Mark; Purohit, Dharmesh [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Saibene, Gabriella; Sartori, Filippo [Fusion for Energy, Josep Pla 2, Barcelona 08019 (Spain); Sozzi, Carlo [Istituto di Fisica del Plasma ENEA-CNR-EURATOM, via Cozzi 53, 20125 Milano (Italy)

    2015-10-15

    The ITER Electron Cyclotron (EC) plant is a complex system, essential for plasma operation. The system is being designed to supply up to 20 MW of power at 170 GHz; it consists of 24 RF sources (or Gyrotrons) connected by switchable transmission lines to four upper and one equatorial launcher. The complexity of the EC plant requires a Plant Controller, which provides the functional and operational interface with CODAC and the Plasma Control System and coordinates the various Subsystem Control Units, i.e. the local controllers of power supplies, Gyrotrons, transmission lines and launchers. A conceptual design of the Electron Cyclotron Control System (ECCS) was developed, starting from the collection of the user requirements, which have then been organized as a set of operational scenarios exploiting the EC system. The design consists in a thorough functional analysis, including also protection functions, and in the development of a conceptual I&C architecture. The main aim of the work was to identify the physics requirements and to translate them into control system requirements, in order to define the interfaces within the components of the ECCS. The definition of these interfaces is urgent because some of the subsystems are already in an advanced design phase. The present paper describes both the methodology used and the resulting design.

  12. Cyclotron maser emission from power-law electrons with strong pitch-angle anisotropy

    CERN Document Server

    Zhao, G Q; Wu, D J; Chen, L; Tang, J F; Liu, Q

    2016-01-01

    Energetic electrons with power-law spectrum are most commonly observed in astrophysics. This paper investigates electron cyclotron maser emission (ECME) from the power-law electrons, in which strong pitch-angle anisotropy is emphasized. The electron distribution function proposed in this paper can describe various types of pitch-angle anisotropy. Results show that the emission properties of ECME, including radiation growth, propagation, and frequency properties, depend considerably on the types of electron pitch-angle anisotropy, and different wave modes show different dependences on the pitch angle of electrons. In particular, the maximum growth rate of X2 mode rapidly decreases with respect to the electron pitch-angle cosine $\\mu_0$ at which the electron distribution peaks, while the growth rates for other modes (X1, O1, O2) initially increase before decreasing as $\\mu_0$ increases. Moreover, the O mode as well as the X mode can be the fastest growth mode, in terms of not only the plasma parameter but also ...

  13. Study of ion beam transport from the SECRAL electron cyclotron resonance ion source at the Institute of Modern Physics.

    Science.gov (United States)

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

    2012-02-01

    Ion beam transport from the Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou (SECRAL) electron cyclotron resonance ion source was studied at the Institute of Modern Physics during 2010. Particle-in-cell simulations and experimental results have shown that both space charge and magnetic aberrations lead to a larger beam envelope and emittance growth. In the existing SECRAL extraction beam line, it has been shown that raising the solenoid lens magnetic field reduces aberrations in the subsequent dipole and results in lower emittance. Detailed beam emittance measurements are presented in this paper.

  14. 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

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W., E-mail: luwang@impcas.ac.cn; Sun, L. T.; Qian, C.; Feng, Y. C.; Ma, H. Y.; Zhang, X. Z.; Ma, B. H.; Zhao, H. W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73000 (China); Guo, J. W.; Fang, X.; Yang, Y. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, B.; Guo, S. Q.; Ruan, L. [Institute of Electrical Engineering, CAS, Beijing 100190 (China)

    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.

  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.

    Science.gov (United States)

    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.

  16. Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Austin, M.E.; Ellis, R.F. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 (United States); Doane, J.L. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); James, R.A. [Lawrence Livermore National Laboratory, Livermore, California 94551-9090 (United States)

    1997-01-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15{percent} to 5{percent}. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms. {copyright} {ital 1997 American Institute of Physics.}

  17. Nonlinear evolution of the electromagnetic electron-cyclotron instability in bi-Kappa distributed plasma

    Energy Technology Data Exchange (ETDEWEB)

    Eliasson, B., E-mail: bengt.eliasson@strath.ac.uk [SUPA, Physics Department, John Anderson Building, Strathclyde University, Glasgow G4 0NG, Scotland (United Kingdom); Lazar, M., E-mail: mlazar@tp4.rub.de [Centre for Mathematical Plasma Astrophysics, Celestijnenlaan 200B, 3001 Leuven (Belgium); Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, 44780 Bochum (Germany)

    2015-06-15

    This paper presents a numerical study of the linear and nonlinear evolution of the electromagnetic electron-cyclotron (EMEC) instability in a bi-Kappa distributed plasma. Distributions with high energy tails described by the Kappa power-laws are often observed in collision-less plasmas (e.g., solar wind and accelerators), where wave-particle interactions control the plasma thermodynamics and keep the particle distributions out of Maxwellian equilibrium. Under certain conditions, the anisotropic bi-Kappa distribution gives rise to plasma instabilities creating low-frequency EMEC waves in the whistler branch. The instability saturates nonlinearly by reducing the temperature anisotropy until marginal stability is reached. Numerical simulations of the Vlasov-Maxwell system of equations show excellent agreement with the growth-rate and real frequency of the unstable modes predicted by linear theory. The wave-amplitude of the EMEC waves at nonlinear saturation is consistent with magnetic trapping of the electrons.

  18. Current drive with combined electron cyclotron wave and high harmonic fast wave in tokamak plasmas

    Science.gov (United States)

    Li, J. C.; Gong, X. Y.; Dong, J. Q.; Wang, J.; Zhang, N.; Zheng, P. W.; Yin, C. Y.

    2016-12-01

    The current driven by combined electron cyclotron wave (ECW) and high harmonic fast wave is investigated using the GENRAY/CQL3D package. It is shown that no significant synergetic current is found in a range of cases with a combined ECW and fast wave (FW). This result is consistent with a previous study [Harvey et al., in Proceedings of IAEA TCM on Fast Wave Current Drive in Reactor Scale Tokamaks (Synergy and Complimentarily with LHCD and ECRH), Arles, France, IAEA, Vienna, 1991]. However, a positive synergy effect does appear with the FW in the lower hybrid range of frequencies. This positive synergy effect can be explained using a picture of the electron distribution function induced by the ECW and a very high harmonic fast wave (helicon). The dependence of the synergy effect on the radial position of the power deposition, the wave power, the wave frequency, and the parallel refractive index is also analyzed, both numerically and physically.

  19. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Moda)

    Science.gov (United States)

    Sung, C.; White, A. E.; Irby, J. H.; Leccacorvi, R.; Vieira, R.; Oi, C. Y.; Peebles, W. A.; Nguyen, X.

    2012-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have kθ ≤ 4.8 cm-1 (kθρs < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

  20. Plasma breakdown diagnostics with the biased disc of electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O; Ropponen, T; Toivanen, V; Arje, J; Koivisto, H [University of Jyvaeskylae, Department of Physics, Accelerator Laboratory, PO Box 35 (YFL), 40500 Jyvaeskylae (Finland)], E-mail: olli.tarvainen@jyu.fi

    2009-08-15

    The electron cyclotron resonance ion sources at the JYFL (University of Jyvaeskylae, Department of Physics) accelerator laboratory have been operated in pulsed mode to study the time-resolved current signal from the biased discs of the ion sources. The purpose of the experiments is to gain an understanding of the ion source parameters affecting the time required for the transition from neutral gas to plasma. It was observed that the plasma breakdown time depends strongly on the neutral gas density, gas species and density of seed electrons. In particular, it was observed that a low power microwave signal at secondary frequency makes the breakdown time virtually independent of the neutral gas density. The results can be utilized for operation of ECR ion sources in the so-called preglow mode. A simple qualitative model, which is in good agreement with the experiments, has been developed to interpret the results.

  1. Starch-based backwards SHG for in situ MEFISTO pulse characterization in multiphoton microscopy.

    Science.gov (United States)

    Anisha Thayil, K N; Gualda, E J; Psilodimitrakopoulos, S; Cormack, I G; Amat-Roldán, I; Mathew, M; Artigas, D; Loza-Alvarez, P

    2008-04-01

    We report a simple methodology to provide complete pulse characterization at the sample plane of a two-photon excited fluorescence (TPEF) microscope. This is achieved by using backward propagating second-harmonic generation (SHG) from starch granules. Without any modification to the microscope, SHG-autocorrelation traces were obtained by using a single starch granule that was placed alongside the biological specimen being imaged. A spectrally resolved SHG autocorrelation was acquired by placing a spectrometer at the output port of the microscope. Complete in situ pulse information is then directly retrieved in an analytical way using the measurement of electric filed by interferometric spectral trace observation (MEFISTO) technique.

  2. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Young, E-mail: beacoolguy@snu.ac.kr; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2016-02-15

    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{sup −} 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{sup −} ion generation in volume-produced negative hydrogen ion sources.

  3. Nonlinear fundamental and harmonic cyclotron resonant scattering of radiation belt ultrarelativistic electrons by oblique monochromatic EMIC waves

    Science.gov (United States)

    Wang, Geng; Su, Zhenpeng; Zheng, Huinan; Wang, Yuming; Zhang, Min; Wang, Shui

    2017-02-01

    Cyclotron resonant scattering by electromagnetic ion cyclotron (EMIC) waves has been considered to be responsible for the rapid loss of radiation belt high-energy electrons. For parallel-propagating EMIC waves, the nonlinear character of cyclotron resonance has been revealed in recent studies. Here we present the first study on the nonlinear fundamental and harmonic cyclotron resonant scattering of radiation belt ultrarelativistic electrons by oblique EMIC waves on the basis of test particle simulations. Higher wave obliquity produces stronger nonlinearity of harmonic resonances but weaker nonlinearity of fundamental resonance. Compared to the quasi-linear prediction, these nonlinear resonances yield a more rapid loss of electrons over a wider pitch angle range. In the quasi-linear regime, the ultrarelativistic electrons are lost in the equatorial pitch angle range αeq87.5° at ψ = 20° and 40°. At the resonant pitch angles αeq<75°, the difference between quasi-linear and nonlinear loss timescales tends to decrease with the wave normal angle increasing. At ψ = 0° and 20°, the nonlinear electron loss timescale is 10% shorter than the quasi-linear prediction; at ψ = 40°, the difference in loss timescales is reduced to <5%.

  4. High field side measurements of non-thermal electron cyclotron emission on TCV plasmas with ECH and ECCD

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, P.; Alberti, S.; Coda, S.; Weisen, H.; Nikkola, P.; Klimanov, I

    2002-07-01

    Measurements of electron cyclotron emission from the high field side of the TCV tokamak have been made on plasmas heated by second and third harmonic X-mode Electron Cyclotron Heating (ECH) and Electron Cyclotron Current Drive (ECCD). Suprathermal Electron Cyclotron Emission (ECE), up to a factor of 6 in excess of thermal emission, is detected in the presence of second harmonic X-mode (X2) ECCD and of third harmonic X-mode (X3) ECH. The measured ECE spectra are modelled using a bi-Maxwellian describing the bulk and the suprathermal electron populations. Suprathermal temperatures between 10-50keV and densities in the range 1. 10{sup 1}7 -6. 10{sup 1}8m{sup -3} are obtained, and correspond to 3 -15 bulk temperatures and 1% -20% bulk densities. Good agreement between ECE suprathermal temperatures and energetic photon temperatures, measured by a hard X-ray camera, is found. For optically thin X3 Low Field Side (LFS) injection in presence of X2 CO-ECCD, the suprathermal population partly explains the discrepancy between global and first pass absorption measurements. (author)

  5. Resonant Scattering of Relativistic Outer Zone Electrons by Plasmaspheric Plume Electromagnetic Ion Cyclotron Waves

    Institute of Scientific and Technical Information of China (English)

    SU Zhen-Peng; ZHENG Hui-Nan

    2009-01-01

    The bounce-averaged Fokker-Planck equation is solved to study the relativistic electron phase space density(PSD)evolution in the outer radiation belt due to resonant interactions with plasmaspheric plume electromagnetic ion cyclotron(EMIC)waves.It is found that the PSDs of relativistic electrons can be depleted by 1-3 orders of magnitude in 5h,supporting the previous finding that resonant interactions with EMIC waves may account for the frequently observed relativistic electron flux dropouts in the outer radiation belt during the main phase of a storm.The significant precipitation Joss of ~Me V electrons is primarily induced by the EMIC waves in H~+ and He~+ bands.The rapid remove of highly relativistic electrons(>5 MeV)is mainly driven by the EMIC waves in O~+ band at lower pitch-angles,as well as the EMIC waves in H~+ and He~+ bands at larger pitch-angles.Moreover,a stronger depletion of relativistic electrons is found to occur over a wider pitch angle range when EMIC waves are centering relatively higher in the band.

  6. Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Choi, M. J., E-mail: mjchoi@nfri.re.kr [National Fusion Research Institute, Daejeon 34133 (Korea, Republic of); Park, H. K. [National Fusion Research Institute, Daejeon 34133 (Korea, Republic of); Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Yun, G. S.; Nam, Y. B.; Choe, G. H. [Pohang University of Science and Technology, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Lee, W. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Jardin, S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2016-01-15

    The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (T{sub e}) fluctuations by measuring the ECE intensity I{sub ECE} ∝ T{sub e} in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat T{sub e} assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (T{sub e,rel}) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

  7. Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

    Science.gov (United States)

    Schwarm, F.-W.; Schönherr, G.; Falkner, S.; Pottschmidt, K.; Wolff, M. T.; Becker, P. A.; Sokolova-Lapa, E.; Klochkov, D.; Ferrigno, C.; Fürst, F.; Hemphill, P. B.; Marcu-Cheatham, D. M.; Dauser, T.; Wilms, J.

    2017-01-01

    Context. Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. Aims: We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. Methods: The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron momenta sampled during these simulations were analyzed and justified using theoretically determined boundaries. Results: We present a complete set of tables suited for mean free path calculations of Monte Carlo simulations of the cyclotron scattering process for conditions expected in typical X-ray pulsar accretion columns (0.01 ≤ B/Bcrit ≤ 0.12, where Bcrit = 4.413 × 1013 G, and 3 keV ≤ kBT ≤ 15 keV). The sampling of the tables is chosen such that the results have an estimated relative error of at most 1/15 for all points in the grid. The tables are available online (see link in footnote, page 1). The electronic tables described here are available at http://www.sternwarte.uni-erlangen.de/research/cyclo

  8. Excitation of electrostatic waves in the electron cyclotron frequency range during magnetic reconnection in laboratory overdense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kuwahata, A., E-mail: kuwahata@ts.t.u-tokyo.ac.jp [Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan); Igami, H. [National Institute for Fusion Science, Toki 509-5292 (Japan); Kawamori, E. [Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan (China); Kogi, Y. [Fukuoka Institute of Technology, Fukuoka 811-0295 (Japan); Inomoto, M.; Ono, Y. [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561 (Japan)

    2014-10-15

    We report the observation of electromagnetic radiation at high harmonics of the electron cyclotron frequency that was considered to be converted from electrostatic waves called electron Bernstein waves (EBWs) during magnetic reconnection in laboratory overdense plasmas. The excitation of EBWs was attributed to the thermalization of electrons accelerated by the reconnection electric field around the X-point. The radiative process discussed here is an acceptable explanation for observed radio waves pulsation associated with major flares.

  9. Diffuse auroral precipitation by resonant interaction with electron cyclotron harmonic and whistler mode waves

    Science.gov (United States)

    Tripathi, A. K.; Singhal, R. P.; Singh, K. P.; Singh, O. N.

    2013-05-01

    Bounce-averaged pitch angle diffusion coefficients of electrons due to resonant interaction with electrostatic electron cyclotron harmonic (ECH) and whistler mode waves have been calculated. Temporal growth rates obtained by solving the appropriate dispersion relation have been used to represent the distribution of wave energy with frequency. Calculations have been performed at two spatial locations L=4.6 and L=6.8. The results obtained suggest that ECH waves can put electrons on strong pitch angle diffusion at both spatial locations. However, at L=4.6, electrons with energy <100 eV and at L=6.8 electrons with energy up to ∼500 eV can be put on strong diffusion contributing to diffuse auroral precipitation. Whistler mode waves can put electrons of energy ≤5 keV on strong pitch angle diffusion at L=6.8 whereas at L=4.6 observed wave fields are insufficient to put electrons on strong diffusion. ECH waves contribute up to 17% of the total electron energy precipitation flux due to both ECH and whistler mode waves. A case study has been performed to calculate pitch angle diffusion coefficients using Gaussian function to represent wave energy distribution with frequency. It is found that, for electron energy <500 eV, the calculated diffusion coefficients using Gaussian function to represent ECH wave energy distribution are several orders of magnitude smaller or negligible as compared to diffusion coefficients calculated by temporal growth rates. However, the calculated pitch angle diffusion coefficients using Gaussian function for whistler mode wave energy distribution are in very good agreement with diffusion coefficients calculated by temporal growth rates. It is concluded that representing the ECH wave energy distribution with frequency by a Gaussian function grossly underestimates the low energy (<500 eV) electron precipitation flux due to ECH waves.

  10. Radiofrequency and 2.45 GHz electron cyclotron resonance H- volume production ion sources

    Science.gov (United States)

    Tarvainen, O.; Peng, S. X.

    2016-10-01

    The volume production of negative hydrogen ions ({{{H}}}-) in plasma ion sources is based on dissociative electron attachment (DEA) to rovibrationally excited hydrogen molecules (H2), which is a two-step process requiring both, hot electrons for ionization, and vibrational excitation of the H2 and cold electrons for the {{{H}}}- formation through DEA. Traditionally {{{H}}}- ion sources relying on the volume production have been tandem-type arc discharge sources equipped with biased filament cathodes sustaining the plasma by thermionic electron emission and with a magnetic filter separating the main discharge from the {{{H}}}- formation volume. The main motivation to develop ion sources based on radiofrequency (RF) or electron cyclotron resonance (ECR) plasma discharges is to eliminate the apparent limitation of the cathode lifetime. In this paper we summarize the principles of {{{H}}}- volume production dictating the ion source design and highlight the differences between the arc discharge and RF/ECR ion sources from both, physics and technology point-of-view. Furthermore, we introduce the state-of-the-art RF and ECR {{{H}}}- volume production ion sources and review the challenges and future prospects of these yet developing technologies.

  11. Development of multichannel intermediate frequency system for electron cyclotron emission radiometer on KSTAR Tokamak.

    Science.gov (United States)

    Kogi, Yuichiro; Sakoda, Takuya; Mase, Atsushi; Ito, Naoki; Yokota, Yuya; Yamaguchi, Soichiro; Nagayama, Yoshio; Jeong, Seung H; Kwon, Myeun; Kawahata, Kazuo

    2008-10-01

    Plasma experiments on KSTAR are scheduled to start up this year (2008). We have developed an electron cyclotron emission (ECE) radiometer to measure the radial electron temperature profiles in KSTAR experiments. The radiometer system consists, briefly, of two downconversion stages, amplifiers, bandpass filter banks, and video detectors. These components are made commercially or developed in house. The system detects ECE power in the frequency range from 110 to 196 GHz, the detected signal being resolved by means of 48 frequency windows. Before installation of this system on KSTAR, we installed a part of this system on large helical device (LHD) to study the system under similar plasma conditions. In this experiment, the signal amplitude, considered to be proportional to the electron temperature, is measured. The time-dependent traces of the electron temperature measured by this radiometer are in good agreement with those provided by the LHD Michelson spectrometer. The system noise level which limits the minimum measurable temperature (converted to the electron temperature) is about 30 eV.

  12. Plasma response measurements of external magnetic perturbations using electron cyclotron emission and comparisons to 3D ideal MHD equilibrium

    NARCIS (Netherlands)

    Willensdorfer, M.; Denk, S. S.; Strumberger, E.; Suttrop, W.; Vanovac, B.; Brida, D.; Cavedon, M.; Classen, I.; Dunne, M.; Fietz, S.; Fischer, R.; Kirk, A.; Laggner, F. M.; Liu, Y. Q.; Odstrcil, T.; Ryan, D. A.; Viezzer, E.; Zohm, H.; Luhmann, I. C.; ASDEX Upgrade team,; EUROfusion MST1 Team,

    2016-01-01

    The plasma response from an external n = 2 magnetic perturbation field in ASDEX Upgrade has been measured using mainly electron cyclotron emission (ECE) diagnostics and a rigid rotating field. To interpret ECE and ECE-imaging (ECE-I) measurements accurately, forward modeling of the radiation

  13. Development of a compact electron-cyclotron-resonance ion source for high-energy carbon-ion therapy

    NARCIS (Netherlands)

    Muramatsu, M; Kitagawa, A; Sakamoto, Y; Sato, S; Sato, Y; Ogawa, H; Yamada, S; Ogawa, H; Yoshida, Y; Drentje, AG

    2005-01-01

    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 10 GHz compact electron-cyclotron-resonance ion source with all-permanent magnets (Kei2

  14. Non-linear effects in electron cyclotron current drive applied for the stabilization of neoclassical tearing modes

    NARCIS (Netherlands)

    Ayten, B.; Westerhof, E.; ASDEX Upgrade team,

    2014-01-01

    Due to the smallness of the volumes associated with the flux surfaces around the O-point of a magnetic island, the electron cyclotron power density applied inside the island for the stabilization of neoclassical tearing modes (NTMs) can exceed the threshold for non-linear effects as derived

  15. Capabilities of the ITER Electron Cyclotron Equatorial Launcher for Heating and Current Drive

    Directory of Open Access Journals (Sweden)

    Ramponi G.

    2012-09-01

    Full Text Available The ITER Electron Cyclotron Equatorial Launcher is designed to be one of the heating systems to assist and sustain the development of various ITER plasma scenarios starting with the very first plasma operation. Here the capabilities for Heating and Current Drive of this system are reviewed. In particular, the optimum launching conditions are investigated for two scenarios at burn, comparing toroidal and poloidal steering options. Then, the EC capabilities are investigated for different plasma parameters corresponding to various phases of the ITER plasma discharge, from current ramp-up up to burn, and for a wide range of magnetic field, focusing in particular on the EC potential for heating and for L to H-mode assist. It is found that the EC system can contribute to a wide range of heating scenarios during the ramp-up of the magnetic field, significantly increasing the applicable range as a function of magnetic field.

  16. Modeling of the influences of multiple modulated electron cyclotron current drive on NTMs in rotating plasma

    Science.gov (United States)

    Long, Chen; Jinyuan, Liu; Ping, Duan; Guangrui, Liu; Xingyu, Bian

    2017-02-01

    In this work, physical models of neoclassical tearing modes (NTMs) including bootstrap current and multiple modulated electron cyclotron current drive model are applied. Based on the specific physical problems during the suppression of NTMs by driven current, this work compares the efficiency of continuous and modulated driven currents, and simulates the physical processes of multiple modulated driven currents on suppressing rotating magnetic island. It is found that when island rotates along the poloidal direction, the suppression ability of continuous driven current can be massively reduced due to current deposition outside the island separatrix and reverse deposition direction at the X point, which can be avoided by current drive modulation. Multiple current drive has a better suppressing effect than single current drive. This work gives realistic numerical simulations by optimizing the model and parameters based on the experiments, which could provide references for successful suppression of NTMs in future advanced tokamak such as international thermonuclear experimental reactor.

  17. Accessibility condition of wave propagation and multicharged ion production in electron cyclotron resonance ion source plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yushi, E-mail: kato@eei.eng.osaka-u.ac.jp; Yano, Keisuke; Nishiokada, Takuya; Nagaya, Tomoki; Kimura, Daiju; Kumakura, Sho; Imai, Youta; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    2016-02-15

    A new tandem type source of electron cyclotron resonance (ECR) plasmas has been constructing for producing synthesized ion beams in Osaka University. Magnetic mirror field configuration with octupole magnets can be controlled to various shape of ECR zones, namely, in the 2nd stage plasma to be available by a pair mirror and a supplemental coil. Noteworthy correlations between these magnetic configurations and production of multicharged ions are investigated in detail, as well as their optimum conditions. We have been considering accessibility condition of electromagnetic and electrostatic waves propagating in ECR ion source plasma, and then investigated their correspondence relationships with production of multicharged ions. It has been clarified that there exits efficient configuration of ECR zones for producing multicharged ion beams experimentally, and then has been suggested from detail accessibility conditions on the ECR plasma that new resonance, i.e., upper hybrid resonance, must have occurred.

  18. Electron cyclotron resonance near the axis of the gas-dynamic trap

    CERN Document Server

    Bagulov, D S

    2014-01-01

    Propagation of an extraordinary electromagnetic wave in the vicinity of electron cyclotron resonance surface in an open linear trap is studied analytically, taking into account inhomogeneity of the magnetic field in paraxial approximation. Ray trajectories are derived from a reduced dispersion equation that makes it possible to avoid the difficulty associated with a transition from large propagation angles to the case of strictly longitudinal propagation. Our approach is based on the theory, originally developed by the Zvonkov and Timofeev [1], who used the paraxial approximation for the magnetic field strength, but did not consider the slope of the magnetic field lines, which led to considerable error, as has been recently noted by Gospodchikov and Smolyakova [2]. We have found ray trajectories in analytic form and demonstrated that the inhomogeneity of both the magnetic field strength and the field direction can qualitatively change the picture of wave propagation and significantly affect the efficiency of ...

  19. Potential applications of a new microwave ECR (electron cyclotron resonance) multicusp plasma ion source

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Status of the ITER Electron Cyclotron Heating and Current Drive System

    Science.gov (United States)

    Darbos, Caroline; Albajar, Ferran; Bonicelli, Tullio; Carannante, Giuseppe; Cavinato, Mario; Cismondi, Fabio; Denisov, Grigory; Farina, Daniela; Gagliardi, Mario; Gandini, Franco; Gassmann, Thibault; Goodman, Timothy; Hanson, Gregory; Henderson, Mark A.; Kajiwara, Ken; McElhaney, Karen; Nousiainen, Risto; Oda, Yasuhisa; Omori, Toshimichi; Oustinov, Alexander; Parmar, Darshankumar; Popov, Vladimir L.; Purohit, Dharmesh; Rao, Shambhu Laxmikanth; Rasmussen, David; Rathod, Vipal; Ronden, Dennis M. S.; Saibene, Gabriella; Sakamoto, Keishi; Sartori, Filippo; Scherer, Theo; Singh, Narinder Pal; Strauß, Dirk; Takahashi, Koji

    2016-01-01

    The electron cyclotron (EC) heating and current drive (H&CD) system developed for the ITER is made of 12 sets of high-voltage power supplies feeding 24 gyrotrons connected through 24 transmission lines (TL), to five launchers, four located in upper ports and one at the equatorial level. Nearly all procurements are in-kind, following general ITER philosophy, and will come from Europe, India, Japan, Russia and the USA. The full system is designed to couple to the plasma 20 MW among the 24 MW generated power, at the frequency of 170 GHz, for various physics applications such as plasma start-up, central H&CD and magnetohydrodynamic (MHD) activity control. The design takes present day technology and extends toward high-power continuous operation, which represents a large step forward as compared to the present state of the art. The ITER EC system will be a stepping stone to future EC systems for DEMO and beyond.

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

    Energy Technology Data Exchange (ETDEWEB)

    Thomae, R., E-mail: rthomae@tlabs.ac.za; Conradie, J.; Fourie, D.; Mira, J.; Nemulodi, F. [iThemba LABS, P.O. Box 722, Somerset West 7130 (South Africa); Kuechler, D.; Toivanen, V. [CERN, BE/ABP/HSL, 1211 Geneva 23 (Switzerland)

    2016-02-15

    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.

  2. Reversed Shear Alfv'en Eigenmode Stabilization by Localized Electron Cyclotron Heating

    Science.gov (United States)

    van Zeeland, M. A.; Lohr, J.; Heidbrink, W. W.; Nazikian, R.; Solomon, W. M.; Gorelenkov, N. N.; Kramer, G. J.; Austin, M. E.; Rhodes, T. L.; Holcomb, C.; Makowski, M. A.; McKee, G. R.; Sharapov, S. E.

    2007-11-01

    Reversed shear Alfv'en eigenmode (RSAE) activity in DIII-D is observed to be stabilized by electron cyclotron heating (ECH) near the minimum of the safety factor (qmin) in neutral beam heated discharges with reversed magnetic shear. The degree of RSAE stabilization and the volume averaged neutron production (Sn) are highly dependent on ECH deposition location relative to qmin. Ideal MHD simulations predict RSAE existence during ECH, indicating that the mode disappearance is due to kinetic effects not taken into account by the ideal MHD model. While discharges with ECH stabilization of RSAEs have higher Sn than discharges with significant RSAE activity, neutron production remains strongly reduced (up to 60%), indicating the bulk of the deficit is not due to RSAEs alone.

  3. Study on the electron-cyclotron-emission diagnostics on JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Cheol Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-09-01

    Diagnostic system for electron cyclotron emission(ECE) in JT-60 have been surveyed. At JT-60 there are three different ECE-systems: a Fourier transformed spectroscopy system(FTS), a grating polycromater system(GPS), and a heterodyne radiometer system(HRS). Each of the systems has been examined to understand the instrumental feature with much attention to the sensitivity and the resolution. FTS has been studied with particular interest because of its continuous and wide spectral coverage and reliable characteristics for calibration. Some topics in instrumentation for FTS are discussed to get an insight on the system specifications optimal for tokamak experiments. Finally, experimental results of FTS with black body radiation at liquid-nitrogen temperature are described in connection with the calibration of the light guiding system for ECE from JT-60 plasma. 14 refs. (Author).

  4. Assessment of Electron-Cyclotron-Current-Drive-Assisted Operation in DEMO

    Directory of Open Access Journals (Sweden)

    Marushchenko N.B.

    2012-09-01

    Full Text Available The achievable efficiency for external current drive through electron-cyclotron (EC waves in a demonstration tokamak reactor is discussed. Two possible reactor designs, one for steady state and one for pulsed operation, are considered. It is found that for midplane injection the achievable current drive efficiency is limited by secondharmonic absorption at levels consistent with previous studies. Propagation through the second-harmonic region can be reduced by moving the launch position to the high-field side (this can be obtained by injecting the beam from an upper port in the vacuum vessel. In this case, beam tracing calculations deliver values for the EC current drive efficiency approaching those usually reported for neutral beam current drive.

  5. Unstable plasma characteristics in mirror field electron cyclotron resonance microwave ion source

    Indian Academy of Sciences (India)

    S K Angra; Parshant Kumar; R R Dongaonkar; R P Bajpai

    2000-05-01

    Electron cyclotron plasma reactor are prone to instabilities in specific input power [3–7] region (150–450 watts). In this region power absorption by gas molecules in the cavity is very poor and enhanced input power gets reflected substantially without increasing ion density. There are abrupt changes in plasma characteristics when input power was decreased from maximum to minimum, it was observed that reflected power changed from < 2% to ∼ 50%. Minimum two jumps in reflected power were noticed in this specific power region and these appear to be highly sensitive to three stub tuner position in the waveguide for this particular input power zone. Unstable plasma region of this source is found to be dependent upon the magnetic field strength. Some changes in reflected power are also noticed with pressure, flow and bias and they are random in nature.

  6. Two-chamber configuration of Bio-Nano electron cyclotron resonance ion source for fullerene modification

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, T., E-mail: uchida-t@toyo.jp [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe 350-8585 (Japan); Rácz, R.; Biri, S. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Muramatsu, M.; Kitagawa, A. [National Institute of Radiological Sciences (NIRS), Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan); Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe 350-8585 (Japan); Faculty of Science and Engineering, Toyo University, Kawagoe 350-8585 (Japan)

    2016-02-15

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Asaji, T., E-mail: asaji@nc-toyama.ac.jp [National Institute of Technology, Toyama College, 13 Hongo, Toyama 939-8630 (Japan); Nakamura, T.; Furuse, M. [National Institute of Technology, Oshima College, 1091-1 Komatsu, Suouoshima, Oshima, Yamaguchi 742-2193 (Japan); Hitobo, T. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama 930-1305 (Japan); Uchida, T. [Graduate School of Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 (Japan); Muramatsu, M. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2016-02-15

    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.

  8. New compact and efficient local oscillator optic system for the KSTAR electron cyclotron emission imaging system

    Science.gov (United States)

    Nam, Y. B.; Lee, D. J.; Lee, J.; Kim, C.; Yun, G. S.; Lee, W.; Park, H. K.

    2016-11-01

    Electron cyclotron emission imaging (ECEI) diagnostic on Korean Superconducting Tokamak Advanced Research utilizes quasi-optical heterodyne-detection method to measure 2D (vertical and radial) Te fluctuations from two toroidally separated poloidal cross section of the plasma. A cylindrical lens local oscillator (LO) optics with optical path length (OPL) 2-2.5 m has been used in the current ECEI system to couple the LO source to the 24 vertically aligned array of ECE detectors. For efficient and compact LO optics employing the Powell lens is proposed so that the OPL of the LO source is significantly reduced from ˜2.0 m to 0.4 m with new optics. The coupling efficiency of the LO source is expected to be improved especially at the edge channels. Results from the optical simulation together with the laboratory test of the prototype optics will be discussed in this paper.

  9. Spectroscopic ellipsometry analysis of silicon nanotips obtained by electron cyclotron resonance plasma etching.

    Science.gov (United States)

    Mendoza-Galván, Arturo; Järrendahl, Kenneth; Arwin, Hans; Huang, Yi-Fan; Chen, Li-Chyong; Chen, Kuei-Hsien

    2009-09-10

    Silicon nanotips fabricated by electron cyclotron resonance plasma etching of silicon wafers are studied by spectroscopic ellipsometry. The structure of the nanotips is composed of columns 100-140 nm wide and spaced by about 200 nm. Ellipsometry data covering a wide spectral range from the midinfrared to the visible are described by modeling the nanotip layer as a graded uniaxial film using the Bruggeman effective medium approximation. The ellipsometry data in the infrared range reveal two absorption bands at 754 and 955 cm(-1), which cannot be resolved with transmittance measurements. These bands indicate that the etching process is accompanied with formation of carbonaceous SiC and CH(n) species that largely modify the composition of the original crystalline silicon material affecting the optical response of the nanotips.

  10. Steady-State Fully Noninductive Current Driven by Electron Cyclotron Waves in a Magnetically Confined Plasma

    Science.gov (United States)

    Sauter, O.; Henderson, M. A.; Hofmann, F.; Goodman, T.; Alberti, S.; Angioni, C.; Appert, K.; Behn, R.; Blanchard, P.; Bosshard, P.; Chavan, R.; Coda, S.; Duval, B. P.; Fasel, D.; Favre, A.; Furno, I.; Gorgerat, P.; Hogge, J.-P.; Isoz, P.-F.; Joye, B.; Lavanchy, P.; Lister, J. B.; Llobet, X.; Magnin, J.-C.; Mandrin, P.; Manini, A.; Marlétaz, B.; Marmillod, P.; Martin, Y.; Mayor, J.-M.; Martynov, A. A.; Mlynar, J.; Moret, J.-M.; Nieswand, C.; Nikkola, P.; Paris, P.; Perez, A.; Pietrzyk, Z. A.; Pitts, R. A.; Pochelon, A.; Pochon, G.; Refke, A.; Reimerdes, H.; Rommers, J.; Scavino, E.; Tonetti, G.; Tran, M. Q.; Troyon, F.; Weisen, H.

    2000-04-01

    A steady-state, fully noninductive plasma current has been sustained for the first time in a tokamak using electron cyclotron current drive only. In this discharge, 123 kA of current have been sustained for the entire gyrotron pulse duration of 2 s. Careful distribution across the plasma minor radius of the power deposited from three 0.5-MW gyrotrons was essential for reaching steady-state conditions. With central current drive, up to 153 kA of current have been fully replaced transiently for 100 ms. The noninductive scenario is confirmed by the ability to recharge the Ohmic transformer. The dependence of the current drive efficiency on the minor radius is also demonstrated.

  11. Optimization of a coaxial electron cyclotron resonance plasma thruster with an analytical model

    Science.gov (United States)

    Cannat, F.; Lafleur, T.; Jarrige, J.; Chabert, P.; Elias, P.-Q.; Packan, D.

    2015-05-01

    A new cathodeless plasma thruster currently under development at Onera is presented and characterized experimentally and analytically. The coaxial thruster consists of a microwave antenna immersed in a magnetic field, which allows electron heating via cyclotron resonance. The magnetic field diverges at the thruster exit and forms a nozzle that accelerates the quasi-neutral plasma to generate a thrust. Different thruster configurations are tested, and in particular, the influence of the source diameter on the thruster performance is investigated. At microwave powers of about 30 W and a xenon flow rate of 0.1 mg/s (1 SCCM), a mass utilization of 60% and a thrust of 1 mN are estimated based on angular electrostatic probe measurements performed downstream of the thruster in the exhaust plume. Results are found to be in fair agreement with a recent analytical helicon thruster model that has been adapted for the coaxial geometry used here.

  12. Optimization of a coaxial electron cyclotron resonance plasma thruster with an analytical model

    Energy Technology Data Exchange (ETDEWEB)

    Cannat, F., E-mail: felix.cannat@onera.fr, E-mail: felix.cannat@gmail.com; Lafleur, T. [Physics and Instrumentation Department, Onera -The French Aerospace Lab, Palaiseau, Cedex 91123 (France); Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universites, UPMC Univ Paris 06, Univ Paris-Sud, Ecole Polytechnique, 91128 Palaiseau (France); Jarrige, J.; Elias, P.-Q.; Packan, D. [Physics and Instrumentation Department, Onera -The French Aerospace Lab, Palaiseau, Cedex 91123 (France); Chabert, P. [Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universites, UPMC Univ Paris 06, Univ Paris-Sud, Ecole Polytechnique, 91128 Palaiseau (France)

    2015-05-15

    A new cathodeless plasma thruster currently under development at Onera is presented and characterized experimentally and analytically. The coaxial thruster consists of a microwave antenna immersed in a magnetic field, which allows electron heating via cyclotron resonance. The magnetic field diverges at the thruster exit and forms a nozzle that accelerates the quasi-neutral plasma to generate a thrust. Different thruster configurations are tested, and in particular, the influence of the source diameter on the thruster performance is investigated. At microwave powers of about 30 W and a xenon flow rate of 0.1 mg/s (1 SCCM), a mass utilization of 60% and a thrust of 1 mN are estimated based on angular electrostatic probe measurements performed downstream of the thruster in the exhaust plume. Results are found to be in fair agreement with a recent analytical helicon thruster model that has been adapted for the coaxial geometry used here.

  13. Electron cyclotron emission measurements by means of a grating polychromator on the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Vries, P.C. de; Kawahata, K.; Nagayama, Y.; Inagaki, S.; Sasao, H.; Ito, Y. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-03-01

    The electron cyclotron emission (ECE) spectrum at the Large Helical Device (LHD) is measured by a 14-channel grating polychromator. During standard operation the polychromator monitors 2nd harmonic frequencies (100-150 GHz) with a spectral resolution of 1.5 GHz. At sufficient high density the 2nd harmonic X-mode polarization is optically thick and can be used to determine the temperature profile. However, the large magnetic field shear in LHD affects the ECE polarization. This effect has been studied numerically. The wave polarization was found to rotate in the laboratory frame. Experiments have been carried out by means of a polarization rotator in the diagnostic waveguide system, which confirmed the calculations. By a proper setting of the polarization rotator, the rotation can be corrected and pure X-mode is detected. Temperature profiles have been measured successfully by the polychromator. (author)

  14. On the criteria guiding the design of the upper electron-cyclotron launcher for ITER

    Directory of Open Access Journals (Sweden)

    Poli E.

    2015-01-01

    Full Text Available Electron cyclotron waves injected from an antenna located in the upper part of the vessel will be employed in ITER to controlMHD instabilities, particularly neoclassical tearingmodes (NTMs. The derivation of the NTM stabilization criteria used up to now to guide the optimization of the launcher is reviewed in this paper and their range of validity elucidated. Possible effects leading to a deterioration of the predicted performance through a broadening of the EC deposition profile are discussed. The most detrimental effect will likely be the scattering of the EC beams from density fluctuations, resulting in a beam broadening in the 100% range. The combined impact of these effects with that of beam misalignment (with respect to the targeted surface is discussed for a time slice of the standard Q = 10 H-mode scenario.

  15. Two-chamber configuration of Bio-Nano electron cyclotron resonance ion source for fullerene modification

    Science.gov (United States)

    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.

  16. Developing laser ablation in an electron cyclotron resonance ion source for actinide detection with AMS

    Energy Technology Data Exchange (ETDEWEB)

    Bauder, W. [Argonne National Laboratory, Physics Division, 9600 S. Cass Ave, Lemont, IL 60439 (United States); University of Notre Dame, Nuclear Science Laboratory, 124 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Pardo, R.C.; Kondev, F.G.; Kondrashev, S.; Nair, C.; Nusair, O. [Argonne National Laboratory, Physics Division, 9600 S. Cass Ave, Lemont, IL 60439 (United States); Palchan, T. [Hebrew University, Racah Institute of Physics, Jerusalem 91904 (Israel); Scott, R.; Seweryniak, D.; Vondrasek, R. [Argonne National Laboratory, Physics Division, 9600 S. Cass Ave, Lemont, IL 60439 (United States); Collon, P. [University of Notre Dame, Nuclear Science Laboratory, 124 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Paul, M. [Hebrew University, Racah Institute of Physics, Jerusalem 91904 (Israel)

    2015-10-15

    A laser ablation material injection system has been developed at the ATLAS electron cyclotron resonance (ECR) ion source for use in accelerator mass spectrometry experiments. Beam production with laser ablation initially suffered from instabilities due to fluctuations in laser energy and cratering on the sample surface by the laser. However, these instabilities were rectified by applying feedback correction for the laser energy and rastering the laser across the sample surface. An initial experiment successfully produced and accelerated low intensity actinide beams with up to 1000 counts per second. With continued development, laser ablation shows promise as an alternative material injection scheme for ECR ion sources and may help substantially reduce cross talk in the source.

  17. Review of highly charged heavy ion production with electron cyclotron resonance ion source (invited)

    Science.gov (United States)

    Nakagawa, T.

    2014-02-01

    The electron cyclotron resonance ion source (ECRIS) plays an important role in the advancement of heavy ion accelerators and other ion beam applications worldwide, thanks to its remarkable ability to produce a great variety of intense highly charged heavy ion beams. Great efforts over the past decade have led to significant ECRIS performance improvements in both the beam intensity and quality. A number of high-performance ECRISs have been built and are in daily operation or are under construction to meet the continuously increasing demand. In addition, comprehension of the detailed and complex physical processes in high-charge-state ECR plasmas has been enhanced experimentally and theoretically. This review covers and discusses the key components, leading-edge developments, and enhanced ECRIS performance in the production of highly charged heavy ion beams.

  18. The influence of the edge density fluctuations on electron cyclotron wave beam propagation in tokamaks

    DEFF Research Database (Denmark)

    Bertelli, N.; Balakin, A.A.; Westerhof, E.

    2010-01-01

    A numerical analysis of the electron cyclotron (EC) wave beam propagation in the presence of edge density fluctuations by means of a quasi-optical code [Balakin A. A. et al, Nucl. Fusion 48 (2008) 065003] is presented. The effects of the density fluctuations on the wave beam propagation...... are estimated in a vacuum beam propagation between the edge density layer and the EC resonance absorption layer. Consequences on the EC beam propagation are investigated by using a simplified model in which the density fluctuations are described by a single harmonic oscillation. In addition, quasi......-optical calculations are shown by using edge density fluctuations as calculated by two-dimensional interchange turbulence simulations and validated with the experimental data [O. E. Garcia et al, Nucl. Fusion 47 (2007) 667]...

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

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, A., E-mail: a-uchi@riken.jp; Ozeki, K.; Higurashi, Y.; Kidera, M.; Komiyama, M.; Nakagawa, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2016-02-15

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Intense highly charged ion beam production and operation with a superconducting electron cyclotron resonance ion source

    Science.gov (United States)

    Zhao, H. W.; Sun, L. T.; Guo, J. W.; Lu, W.; Xie, D. Z.; Hitz, D.; Zhang, X. Z.; Yang, Y.

    2017-09-01

    The superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is a superconducting-magnet-based electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged heavy ion beams. It is one of the best performing ECRISs worldwide and the first superconducting ECRIS built with an innovative magnet to generate a high strength minimum-B field for operation with heating microwaves up to 24-28 GHz. Since its commissioning in 2005, SECRAL has so far produced a good number of continuous wave intensity records of highly charged ion beams, in which recently the beam intensities of 40Ar+ and 129Xe26+ have, for the first time, exceeded 1 emA produced by an ion source. Routine operations commenced in 2007 with the Heavy Ion accelerator Research Facility in Lanzhou (HIRFL), China. Up to June 2017, SECRAL has been providing more than 28,000 hours of highly charged heavy ion beams to the accelerator demonstrating its great capability and reliability. The great achievement of SECRAL is accumulation of numerous technical advancements, such as an innovative magnetic system and an efficient double-frequency (24 +18 GHz ) heating with improved plasma stability. This article reviews the development of SECRAL and production of intense highly charged ion beams by SECRAL focusing on its unique magnet design, source commissioning, performance studies and enhancements, beam quality and long-term operation. SECRAL development and its performance studies representatively reflect the achievements and status of the present ECR ion source, as well as the ECRIS impacts on HIRFL.

  3. The role of seed electrons on the plasma breakdown and preglow of electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O.; Ropponen, T.; Toivanen, V.; Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaskyla, Jyvaskyla 40500 (Finland); Thuillier, T. [LPSC, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, 38026 Grenoble, France and Institut National Polytechnique de Grenoble, 38026 Grenoble (France); Noland, J. [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720 (United States)

    2010-02-15

    The 14 GHz Electron Cyclotron Resonance Ion Source at University of Jyvaeskylae, Department of Physics (JYFL) has been operated in pulsed mode in order to study the plasma breakdown and preglow effect. It was observed that the plasma breakdown time and preglow characteristics are affected by seed electrons provided by a continuous low power microwave signal at secondary frequency. Sustaining low density plasma during the off-period of high power microwave pulses at the primary frequency shifts the charge state distribution of the preglow transient toward higher charge states. This could be exploited for applications requiring fast and efficient ionization of radioactive elements as proposed for the Beta Beam project within the EURISOL design study, for example. In this article we present results measured with helium and neon.

  4. H- ion production in electron cyclotron resonance driven multicusp volume source

    Science.gov (United States)

    Ivanov, A. A.; Rouillé, C.; Bacal, M.; Arnal, Y.; Béchu, S.; Pelletier, J.

    2004-05-01

    We have used the existing magnetic multicusp configuration of the large volume H- source Camembert III to confine the plasma created by seven elementary multidipolar electron cyclotron resonance (ECR) sources, operating at 2.45 GHz. We varied the pressure from 1 to 4 mTorr, while the total power of the microwave generator was varied between 500 W and 1 kW. We studied the plasma created by this system and measured the various plasma parameters, including the density and temperature of the negative hydrogen ions which are compared to the data obtained in a chamber with elementary ECR sources without multicusp magnetic confinement. The electron temperature is lower than that obtained with similar elementary sources in the absence of the magnetic multicusp field. We found that at pressures in the range from 2 to 4 mTorr and microwave power of up to 1 kW, the electron temperature is optimal for H- ion production (0.6-0.8 eV). This could indicate that the multicusp configuration effectively traps the fast electrons produced by the ECR discharge.

  5. Physics and Engineering Design of the ITER Electron Cyclotron Emission Diagnostic

    Science.gov (United States)

    Rowan, W. L.; Austin, M. E.; Houshmandyar, S.; Phillips, P. E.; Beno, J. H.; Ouroua, A.; Weeks, D. A.; Hubbard, A. E.; Stillerman, J. A.; Feder, R. E.; Khodak, A.; Taylor, G.; Pandya, H. K.; Danani, S.; Kumar, R.

    2015-11-01

    Electron temperature (Te) measurements and consequent electron thermal transport inferences will be critical to the non-active phases of ITER operation and will take on added importance during the alpha heating phase. Here, we describe our design for the diagnostic that will measure spatial and temporal profiles of Te using electron cyclotron emission (ECE). Other measurement capability includes high frequency instabilities (e.g. ELMs, NTMs, and TAEs). Since results from TFTR and JET suggest that Thomson Scattering and ECE differ at high Te due to driven non-Maxwellian distributions, non-thermal features of the ITER electron distribution must be documented. The ITER environment presents other challenges including space limitations, vacuum requirements, and very high-neutron-fluence. Plasma control in ITER will require real-time Te. The diagnosic design that evolved from these sometimes-conflicting needs and requirements will be described component by component with special emphasis on the integration to form a single effective diagnostic system. Supported by PPPL/US-DA via subcontract S013464-C to UT Austin.

  6. Stochasticity of the energy absorption in the electron cyclotron resonance; Estocasticidad de la absorcion de energia en la resonancia electron-ciclotronica

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C. [Departamento de Fisica, ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Hernandez A, O

    1998-07-01

    The energy absorption mechanism in cyclotron resonance of the electrons is a present problem, since it could be considered from the stochastic point of view or this related with a non-homogeneous but periodical of plasma spatial structure. In this work using the Bogoliubov average method for a multi periodical system in presence of resonances, the drift equations were obtained in presence of a RF field for the case of electron cyclotron resonance until first order terms with respect to inverse of its cyclotron frequency. The absorbed energy equation is obtained on part of electrons in a simple model and by drift method. It is showed the stochastic character of the energy absorption. (Author)

  7. Electron cyclotron maser instability (ECMI in strong magnetic guide field reconnection

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2017-08-01

    Full Text Available The ECMI model of electromagnetic radiation from electron holes is shown to be applicable to spontaneous magnetic reconnection. We apply it to reconnection in strong current-aligned magnetic guide fields. Such guide fields participate only passively in reconnection, which occurs in the antiparallel components to both sides of the guide-field-aligned current sheets with current carried by kinetic Alfvén waves. Reconnection generates long (the order of hundreds of electron inertial scales electron exhaust regions at the reconnection site X point, which are extended perpendicular to the current and the guide fields. Exhausts contain a strongly density-depleted hot electron component and have properties similar to electron holes. Exhaust electron momentum space distributions are highly deformed, exhibiting steep gradients transverse to both the reconnecting and guide fields. Such properties suggest application of the ECMI mechanism with the fundamental ECMI X-mode emission beneath the nonrelativistic guide field cyclotron frequency in localized source regions. An outline of the mechanism and its prospects is given. Potential applications are the kilometric radiation (AKR in auroral physics, solar radio emissions during flares, planetary emissions and astrophysical scenarios (radiation from stars and compact objects involving the presence of strong magnetic fields and field-aligned currents. Drift of the exhausts along the guide field maps the local field and plasma properties. Escape of radiation from the exhaust and radiation source region still poses a problem. The mechanism can be studied in 2-D particle simulations of strong guide field reconnection which favours 2-D, mapping the deformation of the electron distribution perpendicular to the guide field, and using it in the numerical calculation of the ECMI growth rate. The mechanism suggests also that reconnection in general may become a source of the ECMI with or without guide fields. This is

  8. Electron cyclotron heating and core intrinsic rotation reversal in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Grassie, J. S. de, E-mail: degrassie@fusion.gat.com [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Boedo, J. A. [University of California, San Diego, San Diego, CA 94550 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States)

    2015-12-10

    The effect of electron cyclotron heating (ECH) on the intrinsic rotation profile in DIII-D is shown experimentally. Former DIII-D experiments have shown that ECH tends to cause an interior reduction in the normally co-Ip directed intrinsic rotation profile, and this core rotation can be fully reversed to the opposite direction. This effect is due to a turbulent rearrangement of the interior rotation profile. Here, we show results that there is more than one mechanism causing this. We compare two low density L-mode discharges where the only operational difference is the location of the ECH deposition. At low ECH power, comparable to the Ohmic power, the primary change is in the q-profile accompanied by a reversal of the core intrinsic rotation direction for the more off-axis deposition. The change in the shear of the q-profile fits well with a recent theoretical prediction for this rotation reversal. At higher ECH power, the primary change is in the core electron temperature, Te, accompanied by a hollowing of the rotation profile near the magnetic axis. This effect appears to be due to the change in electron collisionality, consistent with another theoretical, gyrokinetic prediction. The variety of phenomena that could allow ECH to modify the intrinsic rotation profile give some expectation that regions of large velocity shear in the interior could be generated, with the possibility of triggering internal transport barriers.

  9. Design study of electron cyclotron resonance-ion plasma accelerator for heavy ion cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, T., E-mail: ttinoue@juntendo.ac.jp; Sugimoto, S.; Sasai, K. [Graduate School of Medicine, Juntendo University, Tokyo 113–8421 (Japan); Hattori, T. [National Institute of Radiological Sciences, Chiba 263–0024 (Japan)

    2014-02-15

    Electron Cyclotron Resonance-Ion Plasma Accelerator (ECR-IPAC) device, which theoretically can accelerate multiple charged ions to several hundred MeV with short acceleration length, has been proposed. The acceleration mechanism is based on the combination of two physical principles, plasma electron ion adiabatic ejection (PLEIADE) and Gyromagnetic Autoresonance (GYRAC). In this study, we have designed the proof of principle machine ECR-IPAC device and simulated the electromagnetic field distribution generating in the resonance cavity. ECR-IPAC device consisted of three parts, ECR ion source section, GYRAC section, and PLEIADE section. ECR ion source section and PLEIADE section were designed using several multi-turn solenoid coils and sextupole magnets, and GYRAC section was designed using 10 turns coil. The structure of ECR-IPAC device was the cylindrical shape, and the total length was 1024 mm and the maximum diameter was 580 mm. The magnetic field distribution, which maintains the stable acceleration of plasma, was generated on the acceleration center axis throughout three sections. In addition, the electric field for efficient acceleration of electrons was generated in the resonance cavity by supplying microwave of 2.45 GHz.

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

    Science.gov (United States)

    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

  11. Observation of free electron cyclotron resonance in NaAlSi3O8 feldspar: Direct determination of the effective electron mass

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Nicholis, J.E.; Bøtter-Jensen, L.;

    2001-01-01

    We report the first observation of cyclotron resonances in alkali feldspars, using highly sensitive optical detection methods. In Na-feldspar (NaAlSi3O8). a near isotropic effective electron mass value of m(c)(*) = 0.79m, has been determined. The significance of this measurement in terms of the o......We report the first observation of cyclotron resonances in alkali feldspars, using highly sensitive optical detection methods. In Na-feldspar (NaAlSi3O8). a near isotropic effective electron mass value of m(c)(*) = 0.79m, has been determined. The significance of this measurement in terms...

  12. Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak

    Science.gov (United States)

    Pan, X. M.; Yang, Z. J.; Ma, X. D.; Zhu, Y. L.; Luhmann, N. C.; Domier, C. W.; Ruan, B. W.; Zhuang, G.

    2016-11-01

    A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advanced optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.

  13. Electron cyclotron emission radiometer upgrade on the J-TEXT tokamak

    Science.gov (United States)

    Yang, Z. J.; Pan, X. M.; Ma, X. D.; Ruan, B. W.; Zhou, R. B.; Zhang, C.

    2016-11-01

    To meet experimental requirements, the J-TEXT electron cyclotron emission (ECE) diagnostic is being upgraded. The front end antenna and transmission line have been modified and a new 8-channel W-band detecting unit has been developed. The improved ECE system will extend the frequency range from 94.5-124.5 GHz to 80.5-124.5 GHz. This will enable the system to cover the most plasma in the radius direction for BT = 1.8-2.2 T, and it even can cover almost the whole plasma range ρ = - 0.8-0.9 (minus means the high field side) at BT = 1.8 T. A new auxiliary channel bank with 8 narrow band, tunable yttrium iron garnet filters is planned to add to the ECE system. Due to observations along a major radius, perpendicular to BT, and relatively low electron temperature, Doppler and relativistic broadening are minimal and thus high spatial resolution measurements can be made at variable locations with these tunable channels.

  14. Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X. M.; Yang, Z. J., E-mail: yangzj@hust.edu.cn; Ma, X. D.; Ruan, B. W.; Zhuang, G. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Zhu, Y. L. [School of Physics, University of Science and Technology of China, Anhui 230026 (China); Luhmann, N. C.; Domier, C. W. [Davis Millimeter Wave Research Center, University of California, Davis, California 95616 (United States)

    2016-11-15

    A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advanced optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.

  15. Ion Extraction from a Toroidal Electron Cyclotron Resonance Ion Source: a Numerical Feasibility Study

    Science.gov (United States)

    Caliri, Claudia; Volpe, Francesco; Gammino, Santo; Mascali, David

    2013-10-01

    Electron Cyclotron Resonance Ion Sources (ECRIS) are magnetic mirror plasmas of microwave-heated electrons and cold multi-charged ions. The ions are extracted from one end of the mirror and injected in accelerators for nuclear and particle physics studies, hadrontherapy, or neutral beam injection in fusion plasmas. ECRIS devices progressed to higher and higher ion currents and charge states by adopting stronger magnetic fields (beneficial for confinement) and proportionally higher ECR frequencies. Further improvements would require the attainment of ``triple products'' comparable with major fusion experiments. For this, we propose a new, toroidal rather than linear, ECRIS geometry, which would at the same time improve confinement and make better use of the magnetic field. Ion extraction is more complicated than from a linear device, but feasible, as our modeling indicates. Possible techniques involve charge-dependent drifts, divertors, specially designed magnetic fields and associated loss-cones, electrostatic and/or magnetic deflectors, or techniques used in accelerators to transfer particles from one storage ring or accelerator to the next. Here we present single-particle tracings assessing and comparing these extraction techniques.

  16. Scattering of relativistic and ultra-relativistic electrons by obliquely propagating Electromagnetic Ion Cyclotron waves

    Science.gov (United States)

    Uzbekov, Bogdan; Shprits, Yuri Y.; Orlova, Ksenia

    2016-10-01

    Electromagnetic Ion Cyclotron (EMIC) waves are transverse plasma waves that are generated in the Earth magnetosphere by ring current protons with temperature anisotropy in three different bands: below the H+, He+ and O+ ion gyrofrequencies. EMIC events are enhanced during the main phase of a geomagnetic storm when intensifications in the electric field result in enhanced injections of ions and are usually confined to high-density regions just inside the plasmapause or within drainage plumes. EMIC waves are capable of scattering radiation belt electrons and thus provide an important link between the intensification of the electric field, ion populations, and radiation belt electrons. Bounce-averaged diffusion coefficients computed with the assumption of parallel wave propagation are compared to the results of the code that uses the full cold plasma dispersion relation taking into account oblique propagation of waves and higher-order resonances. We study the sensitivity of the scattering rates to a number of included higher-order resonances, wave spectral distribution parameters, wave normal angle distribution parameters, ambient plasma density, and ion composition. Inaccuracies associated with the neglect of higher-order resonances and oblique propagation of waves are compared to potential errors introduced by uncertainties in the model input parameters.

  17. Resonant scattering of plasma sheet electrons leading to diffuse auroral precipitation: 1. Evaluation for electrostatic electron cyclotron harmonic waves

    Science.gov (United States)

    Ni, Binbin; Thorne, Richard M.; Horne, Richard B.; Meredith, Nigel P.; Shprits, Yuri Y.; Chen, Lunjin; Li, Wen

    2011-04-01

    Using statistical wave power spectral profiles obtained from CRRES and the latitudinal distributions of wave propagation modeled by the HOTRAY code, a quantitative analysis has been performed on the scattering of plasma sheet electrons into the diffuse auroral zone by multiband electrostatic electron cyclotron harmonic (ECH) emissions near L = 6 within the 0000-0600 MLT sector. The results show that ECH wave scattering of plasma sheet electrons varies from near the strong diffusion rate (timescale of an hour or less) during active times with peak wave amplitudes of an order of 1 mV/m to very weak scattering (on the timescale of >1 day) during quiet conditions with typical wave amplitudes of tenths of mV/m. However, for the low-energy (˜100 eV to below 2 keV) electron population mainly associated with the diffuse auroral emission, ECH waves are only responsible for rapid pitch angle diffusion (occasionally near the limit of strong diffusion) for a small portion of the electron population with pitch angles αeq 70°. Computations of the bounce-averaged coefficients of momentum diffusion and (pitch angle, momentum) mixed diffusion indicate that both mixed diffusion and energy diffusion of plasma sheet electrons due to ECH waves are very small compared to pitch angle diffusion and that ECH waves have little effect on local electron acceleration. Consequently, the multiple harmonic ECH emissions cannot play a dominant role in the occurrence of diffuse auroral precipitation near L = 6, and other wave-particle interaction mechanisms, such as whistler mode chorus-driven resonant scattering, are required to explain the global distribution of diffuse auroral precipitation and the formation of the pancake distribution in the inner magnetosphere.

  18. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie A [Los Alamos National Laboratory; Kurennoy, Sergey [Los Alamos National Laboratory

    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.

  19. A Proposal for a Novel H- Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization

    Science.gov (United States)

    Tarvainen, O.; Kurennoy, S.

    2009-03-01

    A design for a novel H- 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 TE111 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- 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- ion current, beam emittance and duty factor of the novel source are estimated.

  20. Magnetic field turbulence, electron heating, magnetic holes, proton cyclotron waves, and the onsets of bipolar pulse (electron hole events: a possible unifying scenario

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani

    2003-01-01

    Full Text Available Two electron heating events have been identified on 20 May 1996 when Polar was in the polar cap/polar cusp boundary layer. The electron heating events were located within magnetic holes/cavities/bubbles and were accompanied by nonlinear ± 14 nT peak-to-peak (f ~ 0.6 to 0.7 fcp obliquely propagating proton cyclotron waves. The electrons appear to be heated isotropically. Electric bipolar pulse (electron hole onset events were also detected within the heating events. We propose a scenario which can link the above phenomena. Nonlinear Alfvén waves, generated through cusp magnetic reconnection, propagate down magnetic field lines and locally heat electrons through the ponderomotive force. The magnetic cavity is created through the diamagnetic effect of the heated electrons. Ion heating also occurs through ponderomotive acceleration (but much less than the electrons and the protons generate the electromagnetic proton cyclotron waves through the loss cone instability. The obliquely propagating electromagnetic proton cyclotron waves accelerate bi-streaming electrons, which are the source of free energy for the electron holes.

  1. Current density distributions and sputter marks in electron cyclotron resonance ion sources.

    Science.gov (United States)

    Panitzsch, Lauri; Peleikis, Thies; Böttcher, Stephan; Stalder, Michael; Wimmer-Schweingruber, Robert F

    2013-01-01

    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.

  2. Numerical simulations of gas mixing effect in electron cyclotron resonance ion sources

    Science.gov (United States)

    Mironov, V.; Bogomolov, S.; Bondarchenko, A.; Efremov, A.; Loginov, V.

    2017-01-01

    The particle-in-cell Monte Carlo collisions code nam-ecris is used to simulate the electron cyclotron resonance ion source (ECRIS) plasma sustained in a mixture of Kr with O2 , N2 , Ar, Ne, and He. The model assumes that ions are electrostatically confined in the ECR zone by a dip in the plasma potential. A gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as a mixing gas. The special feature of oxygen is that most of the singly charged oxygen ions are produced after the dissociative ionization of oxygen molecules with a large kinetic energy release of around 5 eV per ion. The increased loss rate of energetic lowly charged ions of the mixing element requires a building up of the retarding potential barrier close to the ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (˜1 V ) compared to pure Kr plasma (˜0.01 V ), with longer confinement times of krypton ions and with much higher ion temperatures. The temperature of the krypton ions is increased because of extra heating by the energetic oxygen ions and a longer time of ion confinement. In calculations, a drop of the highly charged ion currents of lighter elements is observed when adding small fluxes of krypton into the source. This drop is caused by the accumulation of the krypton ions inside plasma, which decreases the electron and ion confinement times.

  3. Numerical simulations of gas mixing effect in electron cyclotron resonance ion sources

    Directory of Open Access Journals (Sweden)

    V. Mironov

    2017-01-01

    Full Text Available The particle-in-cell Monte Carlo collisions code nam-ecris is used to simulate the electron cyclotron resonance ion source (ECRIS plasma sustained in a mixture of Kr with O_{2}, N_{2}, Ar, Ne, and He. The model assumes that ions are electrostatically confined in the ECR zone by a dip in the plasma potential. A gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as a mixing gas. The special feature of oxygen is that most of the singly charged oxygen ions are produced after the dissociative ionization of oxygen molecules with a large kinetic energy release of around 5 eV per ion. The increased loss rate of energetic lowly charged ions of the mixing element requires a building up of the retarding potential barrier close to the ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (∼1  V compared to pure Kr plasma (∼0.01  V, with longer confinement times of krypton ions and with much higher ion temperatures. The temperature of the krypton ions is increased because of extra heating by the energetic oxygen ions and a longer time of ion confinement. In calculations, a drop of the highly charged ion currents of lighter elements is observed when adding small fluxes of krypton into the source. This drop is caused by the accumulation of the krypton ions inside plasma, which decreases the electron and ion confinement times.

  4. Main-ion temperature and plasma rotation measurements based on scattering of electron cyclotron heating waves in ASDEX Upgrade

    DEFF Research Database (Denmark)

    Pedersen, Morten Stejner; Rasmussen, Jesper; Nielsen, Stefan Kragh

    2017-01-01

    We demonstrate measurements of spectra of O-mode electron cyclotron resonance heating (ECRH) waves scattered collectively from microscopic plasma fluctuations in ASDEX Upgrade discharges with an ITER-like ECRH scenario. The measured spectra are shown to allow determination of the main ion...... temperature and plasma rotation velocity. This demonstrates that ECRH systems can be exploited for diagnostic purposes alongside their primary heating purpose in a reactor relevant scenario....

  5. Main-ion temperature and plasma rotation measurements based on scattering of electron cyclotron heating waves in ASDEX Upgrade

    Science.gov (United States)

    Stejner, M.; Rasmussen, J.; Nielsen, S. K.; Jacobsen, A. S.; Korsholm, S. B.; Leipold, F.; McDermott, R. M.; Salewski, M.; Schubert, M.; Stober, J.; Wagner, D. H.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

    2017-07-01

    We demonstrate measurements of spectra of O-mode electron cyclotron resonance heating (ECRH) waves scattered collectively from microscopic plasma fluctuations in ASDEX Upgrade discharges with an ITER-like ECRH scenario. The measured spectra are shown to allow determination of the main ion temperature and plasma rotation velocity. This demonstrates that ECRH systems can be exploited for diagnostic purposes alongside their primary heating purpose in a reactor relevant scenario.

  6. High power millimeter wave experiment of ITER relevant electron cyclotron heating and current drive system.

    Science.gov (United States)

    Takahashi, K; Kajiwara, K; Oda, Y; Kasugai, A; Kobayashi, N; Sakamoto, K; Doane, J; Olstad, R; Henderson, M

    2011-06-01

    High power, long pulse millimeter (mm) wave experiments of the RF test stand (RFTS) of Japan Atomic Energy Agency (JAEA) were performed. The system consists of a 1 MW/170 GHz gyrotron, a long and short distance transmission line (TL), and an equatorial launcher (EL) mock-up. The RFTS has an ITER-relevant configuration, i.e., consisted by a 1 MW-170 GHz gyrotron, a mm wave TL, and an EL mock-up. The TL is composed of a matching optics unit, evacuated circular corrugated waveguides, 6-miter bends, an in-line waveguide switch, and an isolation valve. The EL-mock-up is fabricated according to the current design of the ITER launcher. The Gaussian-like beam radiation with the steering capability of 20°-40° from the EL mock-up was also successfully proved. The high power, long pulse power transmission test was conducted with the metallic load replaced by the EL mock-up, and the transmission of 1 MW/800 s and 0.5 MW/1000 s was successfully demonstrated with no arcing and no damages. The transmission efficiency of the TL was 96%. The results prove the feasibility of the ITER electron cyclotron heating and current drive system.

  7. First principles fluid modelling of magnetic island stabilization by electron cyclotron current drive (ECCD)

    Science.gov (United States)

    Février, O.; Maget, P.; Lütjens, H.; Luciani, J. F.; Decker, J.; Giruzzi, G.; Reich, M.; Beyer, P.; Lazzaro, E.; Nowak, S.; the ASDEX Upgrade Team

    2016-04-01

    Tearing modes are MagnetoHydroDynamics (MHD) instabilities that reduce the performance of fusion devices. They can however be controlled and suppressed using electron cyclotron current drive (ECCD) as demonstrated in various tokamaks. In this work, simulations of island stabilization by ECCD-driven current have been carried out using the toroidal nonlinear 3D full MHD code xtor-2f, in which a current source term modeling the ECCD has been implemented. The efficiency parameter, {η\\text{RF}} , has been computed and its variations with respect to source width and location were also computed. The influence of parameters such as current intensity, source width and position with respect to the island was evaluated and compared to the modified Rutherford equation. We retrieved a good agreement between the simulations and the analytical predictions concerning the variations of control efficiency with source width and position. We also show that the 3D nature of the current source term can lead to the onset of an island if the source term is precisely applied on a rational surface. We report the observation of a flip phenomenon in which the O- and X-points of the island rapidly switch their position in order for the island to take advantage of the current drive to grow.

  8. Fast earthward flows, electron cyclotron harmonic waves, and diffuse auroras: Conjunctive observations and a synthesized scenario

    Science.gov (United States)

    Liang, Jun; Ni, B.; Spanswick, E.; Kubyshkina, M.; Donovan, E. F.; Uritsky, V. M.; Thorne, R. M.; Angelopoulos, V.

    2011-12-01

    We present in this paper multi-instrumental observations and analyses of fast earthward flows, electrostatic electron cyclotron harmonic (ECH) waves, and diffuse auroras, during 8-9 UT on February 5, 2009. The event began with a series of fast earthward flows detected on mid-tail probe THEMIS-C. Subsequently, magnetic dipolarizations and strong ECH wave intensifications were observed on THEMIS-D/E probes at L ˜ 11 in the equatorial plasma sheet. Concurrently, Ground optical instruments detected diffuse auroral intensifications in the region surrounding the ionospheric footprints of the THEMIS probes. Together with the theoretical simulation performed by Ni et al. (2011e), we establish a causal conjunction between the ECH waves and diffuse auroras for the reported event. We also propose that the ECH wave and diffuse auroral intensification were likely triggered by the fast flow activity from the mid-tail and its resulting magnetic dipolarization. We discuss possible mechanisms linking the fast flow and its associated dipolarization to the intensification of ECH wave and diffuse aurora in the outer magnetosphere.

  9. Multiple electron cyclotron power deposition location tracking by break-in-slope analysis in TCV plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Curchod, L; Felici, F; Pochelon, A; Goodman, T P; Moret, J-M; Paley, J I [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association EURATOM - Confederation Suisse, CH - 1015 Lausanne (Switzerland); Decker, J; Peysson, Y, E-mail: loic.curchod@epfl.ch [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2011-11-15

    Modulation of the amplitude of externally injected electron cyclotron (EC) power is a frequent method used to determine the radial power deposition profile in fusion plasmas. There are many tools to analyze the plasma response to the power modulations under quasi-stationary conditions. This paper focuses on the unique ability of the break-in-slope (BIS) method to retrieve a quasi-instantaneous estimate of the power deposition profile at each power step in the modulation, an outcome particularly relevant to track the power deposition location under non-stationary conditions. Here, the BIS analysis method is applied to the signals of a fast and high radial resolution wire-chamber soft x-ray camera in the Tokamak a Configuration Variable (TCV) where the plasma magnetic configuration and thus the EC resonance location are varied during the plasma discharge. As a step to validate this technique before real-time control experiments, the time-varying EC power deposition location of a single beam is successfully monitored by off-line BIS analysis. Simultaneous tracking of deposition locations of two EC beams gives promising results.

  10. Inclined slot-excited annular electron cyclotron resonance plasma source for hyperthermal neutral beam generation.

    Science.gov (United States)

    You, H-J; Kim, D-W; Koo, M; Jang, S-O; Jung, Y-H; Hong, S-H; Lee, B-J

    2011-01-01

    An inclined slot-excited antenna (ISLAN) electron cyclotron resonance (ECR) plasma source is newly designed and constructed for higher flux hyperthermal neutral beam (HNB) generation. The developed ISLAN source is modified from vertical slot-excited antenna (VSLAN) source in two aspects: one is the use of inclined slots instead of vertical slots, and the other is a cusp magnetic field configuration rather than a toroidal configuration. Such modifications allow us to have more uniform arrangement of slots and magnets, then enabling plasma generation more uniform and thinner. Moreover, ECR plasma allows higher ionization rate, enabling plasma density higher even in submillitorr pressures, therefore decreasing the collision rate and∕or the reionization rate of the reflected atoms while passing through the plasma, and eventually getting higher flux of HNBs. In this paper, we report the design features and the plasma characteristics of the ISLAN source by doing plasma measurements and electromagnetic simulations. It was found that ISLAN source can be a high potential source for larger flux HNB generation; the source was found to give higher plasma densities and better uniformities than inductively coupled plasma source, particularly in low pressure ranges. Also, it is important that using ISLAN gives easier matching and better stability, i.e., ISLAN shows similar field patterns and good plasma symmetries irrespective of the variations of the mean diameter of the ring resonator and∕or the presence of a limiter or a reflector, and the operating pressures.

  11. Millimeter-wave, megawatt gyrotron development for ECR (electron cyclotron resonance) heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Jory, H.; Felch, K.; Hess, C.; Huey, H.; Jongewaard, E.; Neilson, J.; Pendleton, R.; Tsirulnikov, M. (Varian Associates, Inc., Palo Alto, CA (USA))

    1990-09-17

    To address the electron cyclotron heating requirements of planned fusion experiments such as the International Thermonuclear Experimental Reactor (ITER) and the Compact Ignition Tokamak (CIT), Varian is developing gyrotrons at frequencies ranging from 100--300 GHz with output power capabilities up to 1 MW CW. Experimental gyrotrons have been built at frequencies between 100--140 GHz, and a study program has addressed the critical elements of designing 280--300 GHz gyrotrons capable of generating CW power levels up to 1 MW. Initial test vehicles at 140 GHz have utilized TE{sub 15,2,1} interaction cavities, and have been designed to generate short-pulse (up to 20 ms) power levels of 1 MW and up to 400 kW CW. Recently, short-pulse power levels of 1040 kW at 38% efficiency have been obtained and average powers of 200 kW have been achieved. Long-pulse operation has been extended to pulse durations of 0.5 seconds at power levels of 400 kW. Gyrotron oscillators capable of generating output powers of 500 kW CW at a frequency of 110 GHz have recently been designed and a prototype is currently being tested. Design work for a 1 MW CW gyrotron at 110 GHz, is in progress. The 1 MW CW tube will employ an output coupling approach where the microwave output is separated from the microwave output. 15 refs., 10 figs., 3 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    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, E-mail: mswon@kbsi.re.kr [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of)

    2016-02-15

    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.

  13. Development of gas pulsing system for electron cyclotron resonance ion sourcea)

    Science.gov (United States)

    Hojo, S.; Honma, T.; Muramatsu, M.; Sakamoto, Y.; Sugiura, A.

    2008-02-01

    A gas-pulsing system for an electron cyclotron resonance ion source with all permanent magnets (Kei2 source) at NIRS has been developed and tested. The system consists of a small vessel (30ml) to reserve CH4 gas and two fast solenoid valves that are installed at both sides of the vessel. They are connected to each other and to the Kei2 source by using a stainless-steel pipe (4mm inner diameter), where the length of the pipe from the valve to the source is 60cm and the conductance is 1.2l /s. From the results of the test, almost 300eμA for a pulsed C4+12 beam was obtained at a Faraday cup in an extraction-beam channel with a pressure range of 4000Pa in the vessel. At this time, the valve has an open time of 10ms and the delay time between the valve open time and the application of microwave power is 100ms. In experiments, the conversion efficiency for input CH4 molecules to the quantity of extracted C4+12 ions in one beam pulse was found to be around 3% and the ratio of the total amount of the gas requirement was only 10% compared with the case of continuous gas provided in 3.3s of repetition in HIMAC.

  14. First results from the new RIKEN superconducting electron cyclotron resonance ion source (invited).

    Science.gov (United States)

    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.

  15. Experiments with biased side electrodes in electron cyclotron resonance ion sources

    CERN Document Server

    Drentje, A G; Uchida, T; Rácz, R; Biri, S

    2015-01-01

    The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses.One route towards a solution consists of attacking the losses in directions (i.e., radial directions) that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six side electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable,...

  16. Experiments with biased side electrodes in electron cyclotron resonance ion sources.

    Science.gov (United States)

    Drentje, A G; Kitagawa, A; Uchida, T; Rácz, R; Biri, S

    2014-02-01

    The output of highly charged ions from an electron cyclotron resonance ion source (ECRIS) consists of ionic losses from a highly confined plasma. Therefore, an increase of the output of the ions of interest always is a compromise between an increase in the confinement and an increase of the losses. One route towards a solution consists of attacking the losses in directions - i.e., radial directions - that do not contribute to the required output. This was demonstrated in an experiment (using the Kei ECRIS at NIRS, Japan) where radial losses were electrostatically reduced by positively biasing one set of six "side" electrodes surrounding the plasma in side-ward directions attached (insulated) to the cylindrical wall of the plasma chamber. Recently new studies were performed in two laboratories using two essentially different ion sources. At the BioNano ECRIS (Toyo University, Japan) various sets of electrodes were used; each of the electrodes could be biased individually. At the Atomki ECRIS (Hungary), one movable, off-axis side electrode was applied in technically two versions. The measurements show indeed a decrease of ionic losses but different effectivities as compared to the biased disk.

  17. Modification of argon impurity transport by electron cyclotron heating in KSTAR H-mode plasmas

    Science.gov (United States)

    Hong, Joohwan; Henderson, S. S.; Kim, Kimin; Seon, C. R.; Song, Inwoo; Lee, H. Y.; Jang, Juhyeok; Park, Jae Sun; Lee, S. G.; Lee, J. H.; Lee, Seung Hun; Hong, Suk-Ho; Choe, Wonho

    2017-03-01

    Experiments with a small amount of Ar gas injection as a trace impurity were conducted in the Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasma ({{B}\\text{T}}   =  2.8 T, {{I}\\text{P}}   =  0.6 MA, and {{P}\\text{NBI}}   =  4.0 MW). 170 GHz electron cyclotron resonance heating (ECH) at 600 and 800 kW was focused along the mid-plane with a fixed major radial position of R   =  1.66 m. The emissivity of the Ar16+ (3.949 {\\mathring{\\text{A}}} ) and Ar15+ (353.860 {\\mathring{\\text{A}}} ) spectral lines were measured by x-ray imaging crystal spectroscopy (XICS) and a vacuum UV (VUV) spectrometer, respectively. ECH reduces the peak Ar15+ emission and increases the Ar16+ emission, an effect largest with 800 kW. The ADAS-SANCO impurity transport code was used to evaluate the Ar transport coefficients. It was found that the inward convective velocity found in the plasma core without ECH was decreased with ECH, while diffusion remained approximately constant resulting in a less-peaked Ar density profile. Theoretical results from the NEO code suggest that neoclassical transport is not responsible for the change in transport, while the microstability analysis using GKW predicts a dominant ITG mode during both ECH and non-ECH plasmas.

  18. Recondensation performance of liquid helium cryostat for a 28 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-02-01

    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(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(5+) ion beam was got when work gas was CH4 while about 262 eμA of C(5+) ion beam was obtained when work gas was C2H2 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vondrasek, R.; Kutsaev, Sergey [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Delahaye, P.; Maunoury, L. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Blvd Henri Becquerel, 14076 Caen (France)

    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.

  1. The targeted heating and current drive applications for the ITER electron cyclotron system

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, M.; Darbos, C.; Gandini, F.; Gassmann, T.; Loarte, A.; Omori, T.; Purohit, D. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Saibene, G.; Gagliardi, M. [Fusion for Energy, Josep Pla 2, Barcelona 08019 (Spain); Farina, D.; Figini, L. [Istituto di Fisica del Plasma CNR, 20125 Milano (Italy); Hanson, G. [US ITER Project Office, ORNL, 1055 Commerce Park, PO Box 2008, Oak Ridge, Tennessee 37831 (United States); Poli, E. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany); Takahashi, K. [Japan Atomic Energy Agency (JAEA), Naka, Ibaraki 311-0193 (Japan)

    2015-02-15

    A 24 MW Electron Cyclotron (EC) system operating at 170 GHz and 3600 s pulse length is to be installed on ITER. The EC plant shall deliver 20 MW of this power to the plasma for Heating and Current Drive (H and CD) applications. The EC system is designed for plasma initiation, central heating, current drive, current profile tailoring, and Magneto-hydrodynamic control (in particular, sawteeth and Neo-classical Tearing Mode) in the flat-top phase of the plasma. A preliminary design review was performed in 2012, which identified a need for extended application of the EC system to the plasma ramp-up, flattop, and ramp down phases of ITER plasma pulse. The various functionalities are prioritized based on those applications, which can be uniquely addressed with the EC system in contrast to other H and CD systems. An initial attempt has been developed at prioritizing the allocated H and CD applications for the three scenarios envisioned: ELMy H-mode (15 MA), Hybrid (∼12 MA), and Advanced (∼9 MA) scenarios. This leads to the finalization of the design requirements for the EC sub-systems.

  2. Effects of electron cyclotron current drive on the evolution of double tearing mode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Guanglan, E-mail: sunguanglan@nciae.edu.cn; Dong, Chunying [Basic Science Section, North China Institute of Aerospace Engineering, Langfang 065000 (China); Duan, Longfang [School of Computer and Remote Sensing Information Technology, North China Institute of Aerospace Engineering, Langfang 065000 (China)

    2015-09-15

    The effects of electron cyclotron current drive (ECCD) on the double tearing mode (DTM) in slab geometry are investigated by using two-dimensional compressible magnetohydrodynamics equations. It is found that, mainly, the double tearing mode is suppressed by the emergence of the secondary island, due to the deposition of driven current on the X-point of magnetic island at one rational surface, which forms a new non-complete symmetric magnetic topology structure (defined as a non-complete symmetric structure, NSS). The effects of driven current with different parameters (magnitude, initial time of deposition, duration time, and location of deposition) on the evolution of DTM are analyzed elaborately. The optimal magnitude or optimal deposition duration of driven current is the one which makes the duration of NSS the longest, which depends on the mutual effect between ECCD and the background plasma. Moreover, driven current introduced at the early Sweet-Parker phase has the best suppression effect; and the optimal moment also exists, depending on the duration of the NSS. Finally, the effects varied by the driven current disposition location are studied. It is verified that the favorable location of driven current is the X-point which is completely different from the result of single tearing mode.

  3. Early evolution of electron cyclotron driven current during suppression of tearing modes in a circular tokamak

    CERN Document Server

    Pratt, J; Westerhof, E

    2016-01-01

    When electron cyclotron (EC) driven current is first applied to the inside of a magnetic island, the current spreads throughout the island and after a short period achieves a steady level. Using a two equation fluid model for the EC current that allows us to examine this early evolution in detail, we analyze high-resolution simulations of a 2/1 classical tearing mode in a low-beta large aspect-ratio circular tokamak. These simulations use a nonlinear 3D reduced-MHD fluid model and the JOREK code. During the initial period where the EC driven current grows and spreads throughout the magnetic island, it is not a function of the magnetic flux. However, once it has reached a steady-state, it should be a flux function. We demonstrate numerically that if sufficiently resolved toroidally, the steady-state EC driven current becomes approximately a flux function. We discuss the physics of this early period of EC evolution and its impact on the size of the magnetic island.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2014-02-01

    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 C5+ 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 C5+ ion beam was got when work gas was CH4 while about 262 eμA of C5+ ion beam was obtained when work gas was C2H2 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yun, E-mail: caoyun@impcas.ac.cn; Li, Jia Qing; Sun, Liang Ting; Zhang, Xue Zhen; Feng, Yu Cheng; Wang, Hui; Ma, Bao Hua; Li, Xi Xia [Institute of Modern Physics, CAS, Lanzhou 730000 (China)

    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.

  7. Recent development of RIKEN 28 GHz superconducting electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Higurashi, Y., E-mail: higurasi@riken.jp; Ohnishi, J.; Ozeki, K.; Kidera, M.; Nakagawa, T. [RIKEN, 2-1 Hirosawa, Wako, Saitama (Japan)

    2014-02-15

    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 U{sup 35+} and ∼230 eμA of U{sup 33+} at the injected radio frequency (RF) power of ∼4 kW (28 GHz). Very recently, to further increase the beam intensity of U{sup 35+}, 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chang Seouk [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); School of Mechanical Engineering, Pusan National University, Pusan 609-735 (Korea, Republic of); Lee, Byoung-Seob; Choi, Seyong; Yoon, Jang-Hee; Kim, Hyun Gyu; Ok, Jung-Woo; Park, Jin Yong; Kim, Seong Jun; Bahng, Jungbae; Hong, Jonggi; Won, Mi-Sook, E-mail: mswon@kbsi.re.kr [Busan Center, Korea Basic Science Institute, Busan 609-735 (Korea, Republic of); Lee, Seung Wook, E-mail: Seunglee@pusan.ac.kr [School of Mechanical Engineering, Pusan National University, Pusan 609-735 (Korea, Republic of)

    2016-02-15

    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{sup 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.

  9. First results with the yin-yang type electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, P. [Department of Physics, University of Jyvaeskylae (JYFL), P.O. Box 35, FI-40014, Jyvaeskylae (Finland)]. E-mail: pekka.suominen@gmail.com; Ropponen, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae (JYFL), P.O. Box 35, FI-40014, Jyvaeskylae (Finland)

    2007-08-01

    Highly charged heavy-ion beams are often produced with Electron Cyclotron Resonance Ion Sources (ECRIS). The so-called conventional minimum-B ECRIS design includes two solenoid magnets and a multipole magnet (usually a hexapole). A minimum-B configuration can also be formed with 'yin-yang' ('baseball') type coils. Such a magnetic field configuration has been extensively tested in magnetic fusion experiments but not for the production of highly charged heavy ions. The application of the afore-mentioned coil structure to the production of multiply charged ion beams was studied. In this paper we present a design of a yin-yang type ion source known as the ARC-ECRIS and some preliminary experimental results. As a result of this work it was found that the ARC-ECRIS plasma is stable and capable of producing multiply charged ions. Many compromises were made in order to keep the costs of the prototype low. As a consequence, significant improvement can be expected in performance if the plasma size is increased and magnetic confinement is improved. At the end of this article an evolution model of the ARC-ECRIS and some future prospects are presented.

  10. The electron cyclotron resonance ion source with arc-shaped coils concept (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Koivisto, H.; Tarvainen, O. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae (Finland); Suominen, P. [CERN, CH-1211 Geneve 23 (Switzerland); Spaedtke, P. [GSI, Darmstadt, Planckstr. 1, 64221 Darmstadt (Germany)

    2012-02-15

    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{sup 4+} beam intensity of up to 2 {mu}A 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.

  11. Diagnostics of plasma decay and afterglow transient of an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O; Ropponen, T; Toivanen, V; Kalvas, T; Arje, J; Koivisto, H, E-mail: olli.tarvainen@jyu.f [University of Jyvaeskylae, Department of Physics, Accelerator Laboratory PO Box 35 (YFL), 40500 Jyvaeskylae (Finland)

    2010-08-15

    The electron cyclotron resonance ion sources at the JYFL (University of Jyvaeskylae, Department of Physics) accelerator laboratory have been operated in pulsed mode to study the decay of bremsstrahlung emission and ion beam currents of different charge states. The purpose of the experiments is to gain understanding on the ion source parameters affecting the afterglow. It was observed that the bremsstrahlung emission characteristics during the afterglow and decay times of extracted ion beam currents are virtually independent of the ion source tuning parameters. The decay time of different charge states was found to be almost inversely proportional to the square of the ion charge. The result is in good agreement with a simple theoretical model based on diffusion of ions from the magnetic field of the ion source. It was observed that the plasma decay time is shorter in the case of the ion source with lower operation frequency and, thus, lower magnetic field strength. The scaling between the ion sources supports a model based on Bohm diffusion, arising from non-linear effects such as instabilities and fluctuating fields in turbulent plasma. The experiments provide information on the mechanisms causing instabilities during the plasma decay.

  12. High yield neutron generator based on a high-current gasdynamic electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Skalyga, V.; Sidorov, A. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova St., Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., Nizhny Novgorod (Russian Federation); Izotov, I.; Golubev, S.; Razin, S. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova St., Nizhny Novgorod (Russian Federation); Strelkov, A. [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna, Moscow Region (Russian Federation); Tarvainen, O.; Koivisto, H.; Kalvas, T. [Department of Physics, University of Jyväskylä, Jyväskylä (Finland)

    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.

  13. The Influence of Neutral Beam Injection on the Heating and Current Drive with Electron Cyclotron Wave on EAST

    Science.gov (United States)

    Chang, Pengxiang; Wu, Bin; Wang, Jinfang; Li, Yingying; Wang, Xiaoguang; Xu, Handong; Wang, Xiaojie; Liu, Yong; Zhao, Hailin; Hao, Baolong; Yang, Zhen; Zheng, Ting; Hu, Chundong

    2016-11-01

    Both neutral beam injection (NBI) and electron cyclotron resonance heating (ECRH) have been applied on the Experimental Advanced Superconducting Tokamak (EAST) in the 2015 campaign. In order to achieve more effective heating and current drive, the effects of NBI on the heating and current drive with electron cyclotron wave (ECW) are analyzed utilizing the code TORAY and experimental data in the shot #54411 and #54417. According to the experimental and simulated results, for the heating with ECW, NBI can improve the heating efficiency and move the power deposition place towards the inside of the plasma. On the other hand, for the electron cyclotron current drive (ECCD), NBI can also improve the efficiency of ECCD and move the place of ECCD inward. These results will be valuable for the center heating, the achievement of fully non-inductive current drive operation and the suppression of magnetohydrodynamic (MHD) instabilities with ECW on EAST or ITER with many auxiliary heating methods. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB101001 and 2014DFG61950) and National Natural Science Foundation of China (Nos. 11405212 and 11175211)

  14. Pitch-angle diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves in planetary magnetospheres

    Directory of Open Access Journals (Sweden)

    A. K. Tripathi

    2011-02-01

    Full Text Available Pitch-angle diffusion coefficients have been calculated for resonant interaction with electrostatic electron cyclotron harmonic (ECH waves in the magnetospheres of Earth, Jupiter, Saturn, Uranus and Neptune. Calculations have been performed at two radial distances of each planet. It is found that observed wave electric field amplitudes in the magnetospheres of Earth and Jupiter are sufficient to put electrons on strong diffusion in the energy range of less than 100 eV. However, for Saturn, Uranus and Neptune, the observed ECH wave amplitude are insufficient to put electrons on strong diffusion at any radial distance.

  15. Pitch-angle diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves in planetary magnetospheres

    Science.gov (United States)

    Tripathi, A. K.; Singhal, R. P.; Singh, K. P.

    2011-02-01

    Pitch-angle diffusion coefficients have been calculated for resonant interaction with electrostatic electron cyclotron harmonic (ECH) waves in the magnetospheres of Earth, Jupiter, Saturn, Uranus and Neptune. Calculations have been performed at two radial distances of each planet. It is found that observed wave electric field amplitudes in the magnetospheres of Earth and Jupiter are sufficient to put electrons on strong diffusion in the energy range of less than 100 eV. However, for Saturn, Uranus and Neptune, the observed ECH wave amplitude are insufficient to put electrons on strong diffusion at any radial distance.

  16. Effect of upflowing field-aligned electron beams on the electron cyclotron waves in the auroral magnetosphere

    Indian Academy of Sciences (India)

    Sushil Kumar; S K Singh; A K Gwal

    2007-04-01

    The role of low density upflowing field-aligned electron beams (FEBs) on the growth rate of the electron cyclotron waves at the frequencies r < ­e, propagating downward in the direction of the Earth's magnetic field, has been analysed in the auroral region at e/e < 1 where e is the plasma frequency and ­e is the gyrofrequency. The FEBs with low to high energy (b) but with low temperature (∥b) have no effect on these waves. The FEBs with b < 1 keV and ∥b (> 1.5 keV) have been found to have significant effect on the growth rate. Analysis has revealed that it is mainly the ∥b which inhibits the growth rate (magnitude) and the range of frequency (bandwidth) of the instability mainly in the higher frequency spectrum. The inhibition in the growth rate and bandwidth increases with increase in ∥b. The FEBs with less b (giving drift velocity) reduce growth rate more than the beams with larger b. The inhibition of growth rate increases with the increase in the ratio e/e indicating that the beams are more effective at higher altitudes.

  17. Diffuse auroral electron scattering by electron cyclotron harmonic and whistler mode waves during an isolated substorm

    Science.gov (United States)

    Horne, R. B.; Thorne, R. M.; Meredith, N. P.; Anderson, R. R.

    2003-07-01

    There are two main theories for the origin of diffuse auroral electron precipitation: precipitation by electrostatic ECH waves and precipitation by whistler mode waves. Here we analyze a case event where whistler mode hiss, chorus, and ECH waves are intensified during a weak substorm injection event to identify the source of particle precipitation. Examination of the particle data shows that there are three sources of free energy: a temperature anisotropy, a loss cone, and a pancake distribution. Instability analysis shows that the temperature anisotropy excites whistler mode hiss whereas both the temperature anisotropy and the pancake distribution contribute to the excitation of chorus. ECH waves are driven unstable by the loss cone. Wave propagation studies show that the path integrated gain of hiss and chorus is almost unaffected by changes in the depth of the loss cone, whereas ECH waves are very sensitive. Analysis of the changes in the resonant energy during propagation shows that the hiss resonates with electrons above a few keV while chorus resonates below a few hundred eV. As a result, neither hiss nor chorus are likely to cause significant electron precipitation from a few hundred eV to a few keV for this event. On the other hand, ECH waves resonate with electrons in the energy range between that for chorus and hiss. ECH waves can scatter electrons with pitch angles of up to 80° into the loss cone. We conclude that ECH waves are responsible for the formation of the pancake distribution and are probably the main component of diffuse auroral precipitation during this event. We suggest that substorm-injected electrons are responsible for the intensification of hiss and ECH waves and that rapid scattering of electrons by ECH waves forms the pancake distribution which then excites chorus. We also suggest that rapid pitch angle scattering by ECH waves could be responsible for double frequency banded chorus emissions.

  18. Production of intense highly charged ion beams by IMP 14.5 GHz electron cyclotron resonance ion source

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new 14.5 GHz Electron Cyclotron Resonance (ECR) ion source has been constructed over the last two years. The source was designed and tested by making use of the latest results from ECR ion source development, such as high mirror magnetic field, large plasma volume, and biased probe. 140μA of O7+, 185μA of Ar11+ and 50 μA of Xe26+ could be produced with a RF power of 800 W. The intense beams of highly charged metallic ions are produced by means of the method of a metal evaporation oven and volatile compound through axial access. The test results are 130μA of Ca11+, 70μA of Ca12+ and 65μA of Fe10+. The ion source has been put into operation for the cyclotron at the Institute of Modern Physics (IMP).

  19. The effects of beam line pressure on the beam quality of an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Toivanen, V., E-mail: ville.toivanen@jyu.f [University of Jyvaeskylae, Department of Physics, Accelerator Laboratory, P.O. Box 35 (YFL), 40500 Jyvaeskylae (Finland); Steczkiewicz, O.; Tarvainen, O.; Ropponen, T.; Arje, J.; Koivisto, H. [University of Jyvaeskylae, Department of Physics, Accelerator Laboratory, P.O. Box 35 (YFL), 40500 Jyvaeskylae (Finland)

    2010-05-01

    The results of a series of measurements studying the possibility to use neutral gas feeding into the beam line as a way to improve the quality of the heavy ion beams produced with an electron cyclotron resonance ion source (ECRIS) are presented. Significant reduction of the beam spot size and emittance can be achieved with this method. The observed effects are presumably due to increased space charge compensation degree of the ion beam in the beam line section between the ion source and the analyzing magnet. This is the region where the neutral gas was injected. It is shown that the effects are independent of the ion source tuning. Transmission measurements through the beam line and K-130 cyclotron have been carried out to study the effects of improved ion beam quality to the transmission efficiency.

  20. Measurement of effect of electron cyclotron heating in a tandem mirror plasma using a semiconductor detector array and an electrostatic energy analyzer

    Science.gov (United States)

    Minami, R.; Imai, T.; Kariya, T.; Numakura, T.; Uehara, M.; Tsumura, K.; Ebashi, Y.; Kajino, S.; Endo, Y.; Nakashima, Y.

    2016-11-01

    Temporally and spatially resolved soft x-ray and end-loss-electron analyses of the electron cyclotron heated plasmas are carried out by using a semiconductor detector array and an electrostatic energy analyzer in the GAMMA 10 tandem mirror. The flux and the energy spectrum of the end loss electrons are measured by a multi-grid energy analyzer. Recently, the electron cyclotron heating power modulation experiments have been started in order to generate and control the high heat flux and to make the edge localized mode-like intermittent heat load pattern for the divertor simulation studies by the use of these detectors for electron properties.

  1. Soft x-ray intensity profile measurements of electron cyclotron heated plasmas using semiconductor detector arrays in GAMMA 10 tandem mirror.

    Science.gov (United States)

    Minami, R; Imai, T; Kariya, T; Numakura, T; Eguchi, T; Kawarasaki, R; Nakazawa, K; Kato, T; Sato, F; Nanzai, H; Uehara, M; Endo, Y; Ichimura, M

    2014-11-01

    Temporally and spatially resolved soft x-ray analyses of electron cyclotron heated plasmas are carried out by using semiconductor detector arrays in the GAMMA 10 tandem mirror. The detector array has 16-channel for the measurements of plasma x-ray profiles so as to make x-ray tomographic reconstructions. The characteristics of the detector array make it possible to obtain spatially resolved plasma electron temperatures down to a few tens eV and investigate various magnetohydrodynamic activities. High power electron cyclotron heating experiment for the central-cell region in GAMMA 10 has been started in order to reduce the electron drag by increasing the electron temperature.

  2. Effect of high energy electrons on H⁻ production and destruction in a high current DC negative ion source for cyclotron.

    Science.gov (United States)

    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.

  3. Fast ion induced shearing of 2D Alfvén eigenmodes measured by electron cyclotron emission imaging.

    Science.gov (United States)

    Tobias, B J; Classen, I G J; Domier, C W; Heidbrink, W W; Luhmann, N C; Nazikian, R; Park, H K; Spong, D A; Van Zeeland, M A

    2011-02-18

    Two-dimensional images of electron temperature perturbations are obtained with electron cyclotron emission imaging (ECEI) on the DIII-D tokamak and compared to Alfvén eigenmode structures obtained by numerical modeling using both ideal MHD and hybrid MHD-gyrofluid codes. While many features of the observations are found to be in excellent agreement with simulations using an ideal MHD code (NOVA), other characteristics distinctly reveal the influence of fast ions on the mode structures. These features are found to be well described by the nonperturbative hybrid MHD-gyrofluid model TAEFL.

  4. Direct measurement of refracted trajectory of transmitting electron cyclotron beam through plasma on the Large Helical Device

    Directory of Open Access Journals (Sweden)

    Takahashi Hiromi

    2015-01-01

    Full Text Available The electron-cyclotron (EC -beam refraction due to the presence of plasma was investigated in the Large Helical Device. The transmitted-EC-beam measurement system was constructed and the beam pattern on the opposite side of the irradiated surface was measured using an IR camera. Clear dependence of the EC-beam refraction on the electron density was observed and the beam shift in the toroidal direction showed good agreement with the ray-trace calculation of TRAVIS. The influence of the peripheral density profile and the thermal effect on the beam refraction were discussed.

  5. Modeling and validation of a mechanistic tool (MEFISTO) for the prediction of critical power in BWR fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Adamsson, Carl, E-mail: carl.adamsson@psi.ch [Westinghouse Electric Sweden, SE-721 63, Vaesteras (Sweden); Le Corre, Jean-Marie, E-mail: lecorrjm@westinghouse.com [Westinghouse Electric Sweden, SE-721 63, Vaesteras (Sweden)

    2011-08-15

    Highlights: > The MEFISTO code efficiently and accurately predicts the dryout event in a BWR fuel bundle, using a mechanistic model. > A hybrid approach between a fast and robust sub-channel analysis and a three-field two-phase analysis is adopted. > MEFISTO modeling approach, calibration, CPU usage, sensitivity, trend analysis and performance evaluation are presented. > The calibration parameters and process were carefully selected to preserve the mechanistic nature of the code. > The code dryout prediction performance is near the level of fuel-specific empirical dryout correlations. - Abstract: Westinghouse is currently developing the MEFISTO code with the main goal to achieve fast, robust, practical and reliable prediction of steady-state dryout Critical Power in Boiling Water Reactor (BWR) fuel bundle based on a mechanistic approach. A computationally efficient simulation scheme was used to achieve this goal, where the code resolves all relevant field (drop, steam and multi-film) mass balance equations, within the annular flow region, at the sub-channel level while relying on a fast and robust two-phase (liquid/steam) sub-channel solution to provide the cross-flow information. The MEFISTO code can hence provide highly detailed solution of the multi-film flow in BWR fuel bundle while enhancing flexibility and reducing the computer time by an order of magnitude as compared to a standard three-field sub-channel analysis approach. Models for the numerical computation of the one-dimensional field flowrate distributions in an open channel (e.g. a sub-channel), including the numerical treatment of field cross-flows, part-length rods, spacers grids and post-dryout conditions are presented in this paper. The MEFISTO code is then applied to dryout prediction in BWR fuel bundle using VIPRE-W as a fast and robust two-phase sub-channel driver code. The dryout power is numerically predicted by iterating on the bundle power so that the minimum film flowrate in the bundle

  6. Production of highly charged heavy ions by 18 GHz superconducting electron cyclotron resonance at Research Center for Nuclear Physics.

    Science.gov (United States)

    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.

  7. Efficient diffuse auroral electron scattering by electrostatic electron cyclotron harmonic waves in the outer magnetosphere: A detailed case study

    Science.gov (United States)

    Ni, Binbin; Liang, Jun; Thorne, Richard M.; Angelopoulos, Vassilis; Horne, Richard B.; Kubyshkina, Marina; Spanswick, Emma; Donovan, Eric F.; Lummerzheim, Dirk

    2012-01-01

    This paper is a companion to a paper by Liang et al. (2011) which reports a causal connection between the intensification of electrostatic ECH waves and the postmidnight diffuse auroral activity in the absence of whistler mode chorus waves at L = 11.5 on the basis of simultaneous observations from THEMIS spacecraft and NORSTAR optical instruments during 8-9 UT on February 5, 2009. In this paper, we use the THEMIS particle and wave measurements together with the magnetically conjugate auroral observations for this event to illustrate an example where electrostatic electron cyclotron harmonic (ECH) waves are the main contributor to the diffuse auroral precipitation. We use the wave and particle data to perform a comprehensive theoretical and numerical analysis of ECH wave driven resonant scattering rates. We find that the observed ECH wave activity can cause intense pitch angle scattering of plasma sheet electrons between 100 eV and 5 keV at a rate of >10-4 s-1 for equatorial pitch angles αeq < 30°. The scattering approaches the strong diffusion limit in the realistic ambient magnetic field to produce efficient precipitation loss of <˜5 keV electrons on a timescale of a few hours or less. Using the electron differential energy flux inside the loss cone estimated based upon the energy-dependent efficiency of ECH wave scattering for an 8-s interval with high resolution wave data available, the auroral electron transport model developed by Lummerzheim (1987) produced an intensity of ˜2.3 kR for the green-line diffuse aurora. Separately, Maxwellian fitting to the electron differential flux spectrum produced a green-line auroral intensity of ˜2.6 kR. This is in good agreement with the ˜2.4 kR green-line auroral intensity observed simultaneously at the magnetic foot point (as inferred using the event-adaptive model of Kubyshkina et al. (2009, 2011)) of the location where the in situ observations were obtained. Our results support the scenario that enhanced ECH

  8. The effects of relativistic broadening and frequency down-shift on electron-cyclotron emission measurements in EAST

    Institute of Scientific and Technical Information of China (English)

    Liu Yong; Han Xiang; Ti Ang; Wang Yu-Min; Ling Bi-Li; Hu Li-Qun; Gao Xiang

    2012-01-01

    This paper presents a theoretical calculation of the effects of relativistic broadening and frequency down-shift on the electron cyclotron emission measurements for a wide range of plasma parameters in the Experimental Advanced Superconducting Tokamak (EAST).The calculation is based on the radiation transfer equation,with the reabsorption and reemission processes taken into account.The broadening effect contributes to the radial resolution of the measurement,and the calculation results indicate that it is ~ 2 cm in the case of the central electron temperature 10 keV.A pseudo radial displacement of the obtained electron temperature profile occurs if the relativistic frequency down-shift effect is not taken into account in the determination of the emission layer position.The shift could be a few centimeters as the electron temperature increases,and this effect should be taken into account.

  9. On the application of electron cyclotron emission imaging to the validation of theoretical models of magnetohydrodynamic activity

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, Ben [University of California, Davis; Boivin, R. L. [General Atomics, San Diego; Boom, J. E. [FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands; Classen, I.G.J. [FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands; Domier, C. W. [University of California, Davis; Donne, A. J.H. [FOM Institute for Plasma Physics Rijnhuizen, Nieuwegein, The Netherlands; Heidbrink, W. [University of California, Irvine; Luhmann, N.C. [University of California, Davis; Munsat, T. [University of Colorado, Boulder; Muscatello, C. M. [University of California, Irvine; Nazikian, Raffi [Princeton Plasma Physics Laboratory (PPPL); Park, H.K. [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Spong, Donald A [ORNL; Turnbull, A. D. [General Atomics; Van Zeeland, Michael [General Atomics; Yun, G. S. [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea

    2011-01-01

    Two-dimensional (2D) imaging of electron temperature perturbations provides a powerful constraint for validating theoretical models describing magnetohydrodynamic plasma behavior. In observation of Alfven wave induced temperature fluctuations, electron cyclotron emission imaging provides unambiguous determination of the 2D eigenmode structure. This has provided support for nonperturbative eigenmode solvers which predict symmetry breaking due to poloidal flows in the fast ion population. It is shown that for Alfven eigenmodes, and in cases where convective flows or saturated perturbations lead to nonaxisymmetric equilibria, electron plasma displacements oriented parallel to a gradient in mean temperature are well defined. Furthermore, during highly dynamic behavior, such as the sawtooth crash, highly resolved 2D temperature behaviors yield valuable insight. In particular, addressing the role of adiabatic heating on time scales much shorter than the resistive diffusion time through the additional diagnosis of local electron density allows progress to be made toward a comprehensive understanding of fast reconnection in tokamak plasmas.

  10. Toroidal mode number estimation of the edge-localized modes using the KSTAR 3-D electron cyclotron emission imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.; Yun, G. S., E-mail: gunsu@postech.ac.kr; Lee, J. E.; Kim, M.; Choi, M. J.; Lee, W. [Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Park, H. K. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Domier, C. W.; Luhmann, N. C. [University of California at Davis, Davis, California 95616 (United States); Sabbagh, S. A.; Park, Y. S. [Columbia University, New York, New York 10027 (United States); Lee, S. G.; Bak, J. G. [National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)

    2014-06-15

    A new and more accurate technique is presented for determining the toroidal mode number n of edge-localized modes (ELMs) using two independent electron cyclotron emission imaging (ECEI) systems in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The technique involves the measurement of the poloidal spacing between adjacent ELM filaments, and of the pitch angle α{sub *} of filaments at the plasma outboard midplane. Equilibrium reconstruction verifies that α{sub *} is nearly constant and thus well-defined at the midplane edge. Estimates of n obtained using two ECEI systems agree well with n measured by the conventional technique employing an array of Mirnov coils.

  11. Ultracompact/ultralow power electron cyclotron resonance ion source for multipurpose applications

    Energy Technology Data Exchange (ETDEWEB)

    Sortais, P.; Lamy, T.; Medard, J.; Angot, J.; Latrasse, L.; Thuillier, T. [Laboratoire de Physique Subatomique et de Cosmologie de Grenoble, UJF-CNRS/IN2P3 - INPG, 53, rue des Martyrs, 38026 Grenoble Cedex (France)

    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

  12. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources.

    Science.gov (United States)

    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

  13. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

    Energy Technology Data Exchange (ETDEWEB)

    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

  14. Nb3Sn superconducting magnets for electron cyclotron resonance ion sources

    Energy Technology Data Exchange (ETDEWEB)

    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

  15. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi; Neri, Lorenzo; Gammino, Santo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Biri, Sándor; Rácz, Richárd; Pálinkás, József [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/c, H-4026 Debrecen (Hungary); Caliri, Claudia [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università degli Studi di Catania, Dip.to di Fisica e Astronomia, via Santa Sofia 64, 95123 Catania (Italy); Romano, Francesco Paolo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy); Torrisi, Giuseppe [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, DIIES, Via Graziella, I-89100 Reggio Calabria (Italy)

    2016-02-15

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed “on-line” during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.

  16. Plasma-Sheath Instability in Hall Thrusters Due to Periodic Modulation of the Energy of Secondary Electrons in Cyclotron Motion

    Energy Technology Data Exchange (ETDEWEB)

    Sydorenko, D.; Smolyakov, A.; Kaganovich, I.; Raitses, Y.

    2008-04-23

    Particle-in-cell simulation of Hall thruster plasmas reveals a plasma-sheath instability manifesting itself as a rearrangement of the plasma sheath near the thruster channel walls accompanied by a sudden change of many discharge parameters. The instability develops when the sheath current as a function of the sheath voltage is in the negative conductivity regime. The major part of the sheath current is produced by beams of secondary electrons counter-streaming between the walls. The negative conductivity is the result of nonlinear dependence of beam-induced secondary electron emission on the plasma potential. The intensity of such emission is defined by the beam energy. The energy of the beam in crossed axial electric and radial magnetic fields is a quasi-periodical function of the phase of cyclotron rotation, which depends on the radial profile of the potential and the thruster channel width. There is a discrete set of stability intervals determined by the final phase of the cyclotron rotation of secondary electrons. As a result, a small variation of the thruster channel width may result in abrupt changes of plasma parameters if the plasma state jumps from one stability interval to another.

  17. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited).

    Science.gov (United States)

    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.

  18. Observation and characterization of the effect of electron cyclotron waves on toroidal rotation in EAST L-mode discharges

    Science.gov (United States)

    Chen, Jun; Hu, Ruiji; Lyu, Bo; Wang, Fudi; Wang, Xiaojie; Xu, Handong; Li, Yingying; Fu, Jia; Yin, Xianghui; Wu, Dajun; Liu, Fukun; Zang, Qing; Liu, Haiqing; Shi, Yuejiang; Mao, Shifeng; Yu, Yi; Wang, Baonian; Ye, Minyou; Shen, Yongcai; EAST Team

    2017-10-01

    The change in the toroidal rotation of plasma caused by electron cyclotron wave (ECW) injection has been observed in EAST. It is found that the response of the rotation is similar for all possible ECW toroidal injection angles. The core toroidal rotation velocity increases in the co-current direction along with a rise in the plasma temperature and stored energy. The profile of the electron temperature, ion temperature and toroidal rotation velocity gradually become peaked. The change in toroidal rotation in the core increases with the ECW injection power. Different behavior is observed when the ECWs are injected into low hybrid current drive (LHCD) target plasmas, where the electron temperature and rotation profile become peaked, while the ion temperature profile flattens after ECW injection, suggesting different transport characteristics in energy and momentum.

  19. First operation and effect of a new tandem-type ion source based on electron cyclotron resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yushi, E-mail: kato@eei.eng.osaka-u.ac.jp; Kimura, Daiju; Yano, Keisuke; Kumakura, Sho; Imai, Youta; Nishiokada, Takuya; Nagaya, Tomoki; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    2016-02-15

    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.

  20. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Donghui [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Huang, Mei [Southwestern Institute of Physics, 610041 Chengdu (China); Wang, Zhijiang, E-mail: wangzj@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhang, Feng [Southwestern Institute of Physics, 610041 Chengdu (China); Zhuang, Ge [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)

    2016-10-15

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  1. Non-linear effects in electron cyclotron current drive applied for the stabilization of neoclassical tearing modes

    CERN Document Server

    Ayten, B

    2013-01-01

    Due to the smallness of the volumes associated with the flux surfaces around the O-point of a magnetic island, the electron cyclotron power density applied inside the island for the stabilization of neoclassical tearing modes (NTMs) can exceed the threshold for non-linear effects as derived previously by Harvey et al, Phys. Rev. Lett. 62 (1989) 426. We study the non-linear electron cyclotron current drive (ECCD) efficiency through bounce-averaged, quasi-linear Fokker-Planck calculations in the magnetic geometry as created by the islands. The calculations are performed for the parameters of a typical NTM stabilization experiment on ASDEX Upgrade. A particular feature of these experiments is that the rays of the EC wave beam propagate tangential to the flux surfaces in the power deposition region. The calculations show significant non-linear effects on the ECCD efficiency, when the ECCD power is increased from its experimental value of 1 MW to a larger value of 4 MW. The nonlinear effects are largest in case of...

  2. ITER Plasma at Electron Cyclotron Frequency Domain: Stimulated Raman Scattering off Gould-Trivelpiece Modes and Generation of Suprathermal Electrons and Energetic Ions

    Science.gov (United States)

    Stefan, V. Alexander

    2011-04-01

    Stimulated Raman scattering in the electron cyclotron frequency range of the X-Mode and O-Mode driver with the ITER plasma leads to the ``tail heating'' via the generation of suprathermal electrons and energetic ions. The scattering off Trivelpiece-Gould (T-G) modes is studied for the gyrotron frequency of 170GHz; X-Mode and O-Mode power of 24 MW CW; on-axis B-field of 10T. The synergy between the two-plasmon decay and Raman scattering is analyzed in reference to the bulk plasma heating. Supported in part by Nikola TESLA Labs, La Jolla, CA

  3. High-harmonic electron bunching in the field of a signal wave and the use of this effect in cyclotron masers with frequency multiplication

    Directory of Open Access Journals (Sweden)

    I. V. Bandurkin

    2005-01-01

    Full Text Available A method of organizing electron-wave interaction at the multiplied frequency of the signal wave is proposed. This type of electron-wave interaction provides multiplied-frequency electron bunching, which leads to formation of an intense harmonic of the electron current at a selected multiplied frequency of the signal wave. This effect is attractive for the use in klystron-type cyclotron masers with frequency multiplication as a way to increase the output frequency and improve the selectivity.

  4. Effects of permanent magnet arrangements and antenna locations on the generation of multicusp electron cyclotron resonance plasma

    Energy Technology Data Exchange (ETDEWEB)

    Namura, T. (Kyoto Research Laboratory, Matsushita Electronics Corporation, Kyoto 601 (Japan)); Arikata, I. (Himeji Institute of Technology, Syosha, Himeji 671-22 (Japan)); Fukumasa, O. (Department of Electrical Engineering, Yamaguchi University, Ube 755 (Japan)); Kubo, M.; Itatani, R. (Department of Electronics, Kyoto University, Kyoto 606 (Japan))

    1992-01-01

    A comparative study on the generation of 2.45-GHz multicusp electron cyclotron resonance (ECR) plasma is performed. Looped cusp structures such as the ring-cusp give a low-power and low-pressure ignition, and vice versa, indicating an importance to keep the electron trajetory of gradient-{ital B} drift motion inside the chamber even in the case of ECR plasmas. The importance of the antenna location in such multicusp fields is elucidated by comparison in two cases of the axial antenna located in the weak magnetic field region, generating a hydrogen plasma of limited density ({ital n}{sub {ital e}}{lt}7.4{times}10{sup 10} cm{sup {minus}3}), and a radial antenna located in the strong magnetic field region, generating an overdense plasma ({ital n}{sub {ital e}}{similar to}2{times}10{sup 11} cm{sup {minus}3}).

  5. Helium-Charged Titanium Films Deposited by Pulsed Laser Deposition in an Electron-Cyclotron-Resonance Helium Plasma Environment

    Institute of Scientific and Technical Information of China (English)

    金钦华; 胡佩钢; 凌浩; 吴嘉达; 施立群; 周筑颖

    2003-01-01

    Titanium thin films incorporated with helium are produced by pulsed laser deposition in an electron cyclotron resonance helium plasma environment. Helium is distributed evenly in the film and a relatively high He/Ti atomic ratio (~ 20%) is obtained from the proton backscattering spectroscopy. This high concentration ofhelium leads to a surface blistering which is observed by scanning electron microscopy. Laser repetition rate has little influence on film characters. Substrate bias voltage is also changed for the helium incorporating mechanism study, and this is a helium ion implantation process during the film growth. Choosing suitable substrate bias voltage, one can avoid the damage produced by ion implantation, which is always present in general implantation case.

  6. Cyclotron Institute Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Henry [Texas A& M University; Yennello, Sherry [Texas A& M University; Tribble, Robert [Texas A& M University

    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.

  7. Transient void, pressure drop and critical power BFBT benchmark analysis and results with VIPRE-W / MEFISTO-T

    Energy Technology Data Exchange (ETDEWEB)

    Le Corre, J.M.; Adamsson, C.; Alvarez, P., E-mail: lecorrjm@westinghouse.com, E-mail: carl.adamsson@psi.ch, E-mail: alvarep@westinghouse.com [Westinghouse Electric Sweden AB (Sweden)

    2011-07-01

    A benchmark analysis of the transient BFBT data [1], measured in an 8x8 fuel assembly design under typical BWR transient conditions, was performed using the VIPRE-W/MEFISTO-T code package. This is a continuation of the BFBT steady-state benchmark activities documented in [2] and [3]. All available transient void and pressure drop experimental data were considered and the measurements were compared with the predictions of the VIPRE-W sub-channel analysis code using various modeling approaches, including the EPRI drift flux void correlation. Detailed analyses of the code results were performed and it was demonstrated that the VIPRE-W transient predictions are generally reliable over the tested conditions. Available transient dryout data were also considered and the measurements were compared with the predictions of the VIPRE-W/ MEFISTO-T film flow calculations. The code calculates the transient multi-film flowrate distributions in the BFBT bundle, including the effect of spacer grids on drop deposition enhancement, and the dryout criterion corresponds to the total liquid film disappearance. After calibration of the grid enhancement effect with a very small subset of the steady-state critical power database, the code could predict the time and location of transient dryout with very good accuracy. (author)

  8. Monitoring of the current profile by using cyclotronic electron waves in tokamaks; Controle du profil de courant par ondes cyclotroniques electroniques dans les tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, R

    2001-08-01

    The subject of this thesis is the study of the cyclotronic electron wave as a monitoring tool of the current profile. The first chapter is dedicated to basic notions concerning tokamak plasmas and current generation. The second chapter is centered on the use of fast electrons to generate current and on its modelling. The propagation and absorption of the cyclotronic electron wave require a specific polarization state whose characteristics must be carefully chosen according to some parameters of the discharge, the chapter 3 deals with this topic. The absorption of a wave in a plasma depends greatly on the velocity distribution of the particles that make up the plasma and this distribution is constantly modified by the energy of the wave, so this phenomenon is non-linear and its physical description is difficult. In a case of a fusion plasma, a sophisticated approximation called quasi-linear theory can be applied with some restrictions that are presented in chapter 4. Chapters 5 and 6 are dedicated to kinetics scenarios involving the low hybrid wave and the cyclotronic electron wave inside the plasma. Some experiments dedicated to the study of the cyclotronic electron wave have been performed in Tore-supra (France) and FTU (Italy) tokamaks, they are presented in the last chapter. (A.C.)

  9. Generation of lower and upper bands of electrostatic electron cyclotron harmonic waves in the Van Allen radiation belts

    Science.gov (United States)

    Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; He, Yihua; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.

    2017-06-01

    Electrostatic electron cyclotron harmonic (ECH) waves generated by the electron loss cone distribution can produce efficient scattering loss of plasma sheet electrons, which has a significant effect on the dynamics in the outer magnetosphere. Here we report two ECH emission events around the same location L≈ 5.7-5.8, MLT ≈ 12 from Van Allen Probes on 11 February (event A) and 9 January 2014 (event B), respectively. The spectrum of ECH waves was centered at the lower half of the harmonic bands during event A, but the upper half during event B. The observed electron phase space density in both events is fitted by the subtracted bi-Maxwellian distribution, and the fitting functions are used to evaluate the local growth rates of ECH waves based on a linear theory for homogeneous plasmas. ECH waves are excited by the loss cone instability of 50 eV-1 keV electrons in the lower half of harmonic bands in the low-density plasmasphere in event A, and 1-10 keV electrons in the upper half of harmonic bands in a relatively high-density region in event B. The current results successfully explain observations and provide a first direct evidence on how ECH waves are generated in the lower and upper half of harmonic frequency bands.

  10. Cyclotrons: 1978

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.A. (comp.)

    1978-01-01

    A compilation is presented of the experimental facilities of the world's cyclotrons including history and status, staff and operation, research staff, target facilities, magnet, acceleration system, vacuum system, characteristic beams, beam properties, and a plan view of the facility for each cyclotron. (GHT)

  11. G2DEM: a parallel two-dimensional electromagnetic PIC code for the study of electron-cyclotron instabilities of relativistic electron beams in cylindrical cavities

    Energy Technology Data Exchange (ETDEWEB)

    Jost, G.; Tran, T.M.; Appert, K. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP); Wuethrich, S. [CRAY Research, PATP/PSE, EPFL, Lausanne (Switzerland)

    1996-12-01

    A two-dimensional PIC code aimed at the investigation of electron-cyclotron beam instabilities in gyrotrons and their effects on the beam quality is presented. The code is based on recently developed techniques for handling charge conservation and open boundaries and uses an electromagnetic field which is decomposed in its transverse magnetic (TM) and electric (TE) components. The code has been implemented on the massively parallel computer CRAY T3D, and on the CRAY Y-MP. (author) figs., tabs., refs.

  12. Enhancement of Ar sup 8 sup + ion beam intensity from RIKEN 18 GHz electron cyclotron resonance ion source by optimizing the magnetic field configuration

    CERN Document Server

    Higurashi, Y; Kidera, M; Kase, M; Yano, Y; Aihara, T

    2003-01-01

    We successfully produced a 1.55 emA Ar sup 8 sup + ion beam using the RIKEN 18 GHz electron cyclotron resonance ion source at a microwave power of 700 W. To produce such an intense beam, we optimized the minimum magnetic field of mirror magnetic field and plasma electrode position. (author)

  13. Intertwisted fibrillar diamond-like carbon films prepared by electron cyclotron resonance microwave plasma enhanced chemical vapour deposition

    Institute of Scientific and Technical Information of China (English)

    杨武保; 王久丽; 张谷令; 范松华; 刘赤子; 杨思泽

    2003-01-01

    In this paper, the structures, optical and mechanical properties of diamond-like carbon films are studied, which are prepared by a self-fabricated electron cyclotron resonance microwave plasma chemical vapour deposition method at room temperature in the ambient gases of mixed acetylene and nitrogen. The morphology and microstructure of the processed film are characterized by the atomic force microscope image, Raman spectra and middle Fourier transform infrared transmittance spectra, which reveal that there is an intertwisted fibrillar diamond-like structure in the film and the film is mainly composed of sp3 CH, sp3 C-C, sp2 C=C, C=N and C60. The film micro-hardness and bulk modulus are measured by a nano-indenter and the refractive constant and deposition rate are also calculated.

  14. A multi-sample changer coupled to an electron cyclotron resonance source for accelerator mass spectrometry experiments.

    Science.gov (United States)

    Vondrasek, R; Palchan, T; Pardo, R; Peters, C; Power, M; Scott, R

    2014-02-01

    A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving between samples in 1 min. The sample changer is part of a project using Accelerator Mass Spectrometry (AMS) at the Argonne Tandem Linac Accelerator System (ATLAS) facility to measure neutron capture rates on a wide range of actinides in a reactor environment. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly charged positive ions in an electron cyclotron resonance ion source followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation chosen to limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples.

  15. Optimization of the optical system for electron cyclotron emission imaging diagnostics on the HL-2A tokamak

    Science.gov (United States)

    Jiang, Min; Shi, Zhongbing; Zhu, Yilun

    2017-08-01

    The optical system of the electron cyclotron emission imaging diagnostics on the HL-2A tokamak has been optimized in both the narrow zoom pattern and the wide zoom pattern. The two main features of the improved optical system are (1) larger coverage of the measurement region in the plasma and (2) a flatter imaging surface. The new optics has good focal characteristics over the whole plasma cross section. The curvature of the field of the image surface (ΔR between the core channel and the edge channel) is within 5.3 cm in the narrow zoom pattern and 6.7 cm in the wide zoom pattern after optimization, whereas the values with the present optics were 23 cm in the narrow zoom pattern and 15 cm in the wide zoom pattern. The optics will be fabricated, tested and installed on the HL-2A tokamak before the next experimental campaign.

  16. Sawtooth control using electron cyclotron current drive in the presence of energetic particles in high performance ASDEX Upgrade plasmas

    CERN Document Server

    Chapman, I T; Maraschek, M; McCarthy, P J; Tardini, G

    2013-01-01

    Sawtooth control using steerable electron cyclotron current drive (ECCD) has been demonstrated in ASDEX Upgrade plasmas with a significant population of energetic ions in the plasma core and long uncontrolled sawtooth periods. The sawtooth period is found to be minimised when the ECCD resonance is swept to just inside the q = 1 surface. By utilising ECCD inside q = 1 for sawtooth control, it is possible to avoid the triggering of neoclassical tearing modes, even at significnatly higher pressure than anticipated in the ITER baseline scenario. Operation at 25% higher normalised pressure has been achieved when only modest ECCD power is used for sawtooth control compared to identical discharges without sawtooth control when neo-classical tearing modes are triggered by the sawteeth. Modelling suggests that the destabilisation arising from the change in the local magnetic shear caused by the ECCD is able to compete with the stabilising influence of the energetic particles inside the q = 1 surface.

  17. Conceptual design of first toroidal electron cyclotron resonance ion source and modeling of ion extraction from it

    CERN Document Server

    Caliri, C; Volpe, F A

    2015-01-01

    Electron Cyclotron Resonance Ion Sources (ECRIS) progressed to higher and higher ion currents and charge states by adopting stronger magnetic fields (beneficial for confinement) and proportionally higher ECR frequencies. Further improvements would require the attainment of "triple products" of density, temperature and confinement time comparable with major fusion experiments. For this, we propose a new, toroidal rather than linear, ECRIS geometry, which would at the same time improve confinement and make better use of the magnetic field. Ion extraction is more complicated than from a linear device, but feasible, as our modelling suggests: single-particle tracings showed successful extraction by at least two techniques, making use respectively of a magnetic extractor and of ExB drifts. Additional techniques are briefly discussed.

  18. One-dimensional ordinary-slow extraordinary-Bernstein mode conversion in the electron cyclotron range of frequencies

    Science.gov (United States)

    Guo, Xingyu; Gao, Zhe; Jia, Guozhang

    2017-08-01

    The ordinary-slow extraordinary-Bernstein (O-SX-B) mode conversion in the electron cyclotron range of frequencies (ECRF) is revisited in slab geometry. The analytical formula of the O-SX conversion efficiency by Mjølhus is upgraded to include the magnetic field gradient, and the analytical expression of the SX-B conversion efficiency by Ram and Schultz is generalized for the case of oblique injection. Therefore, the conversion efficiency and optimal parallel refractive index for the whole O-SX-B conversion are obtained analytically and a shift of optimal parallel refractive index due to SX-FX loss is found. Full wave calculations are also presented to be compared with the analytical results.

  19. Gas phase proton affinities of molecules in excited electronic states by ion cyclotron resonance spectroscopy. [Benzaldehyde, cyanobenzene, and pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Freiser, B.S.; Beauchamp, J.L.

    1976-01-07

    Ion cyclotron resonance spectroscopy is proposed as a method to determine acid-base properties of molecules in excited electronic states. Proton affinity in the excited state can be determined from the proton affinity in the ground state plus the difference in excitation energies of the base and its conjugate acid. The difference in excitation energies may be determined by analyzing the absorption spectra of the base and the photodissociation spectra of its conjugate acid. Gas phase absorption spectra of benzaldehyde, cyanobenzene and pyradine and their respective conjugate acids were presented and discussed. The greatest increase of proton affinity was reported in the excitation state of benzaldehyde with lesser increases reported for the excitation states of cyanobenzene and pyridine. (DDA)

  20. Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

    Science.gov (United States)

    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.

  1. Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Toivanen, V., E-mail: ville.aleksi.toivanen@cern.ch; Küchler, D. [European Organization for Nuclear Research (CERN), 1211 Geneva 23 (Switzerland)

    2016-02-15

    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. Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    Science.gov (United States)

    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.

  3. Plasma response measurements of external magnetic perturbations using electron cyclotron emission and comparisons to 3D ideal MHD equilibrium

    CERN Document Server

    Willensdorfer, M; Strumberger, E; Suttrop, W; Vanovac, B; Brida, D; Cavedon, M; Classen, I; Dunne, M; Fietz, S; Fischer, R; Kirk, A; Laggner, F M; Liu, Y Q; Odstrcil, T; Ryan, D A; Viezzer, E; Zohm, H; Luhmann, I C

    2016-01-01

    The plasma response from an external n = 2 magnetic perturbation field in ASDEX Upgrade has been measured using mainly electron cyclotron emission (ECE) diagnostics and a rigid rotating field. To interpret ECE and ECE-imaging (ECE-I) measurements accurately, forward modeling of the radiation transport has been combined with ray tracing. The measured data is compared to synthetic ECE data generated from a 3D ideal magnetohydrodynamics (MHD) equilibrium calculated by VMEC. The measured amplitudes of the helical displacement in the midplane are in reasonable agreement with the one from the synthetic VMEC diagnostics. Both exceed the vacuum field calculations and indicate the presence of an amplified kink response at the edge. Although the calculated magnetic structure of this edge kink peaks at poloidal mode numbers larger than the resonant components |m| > |nq|, the displacement measured by ECE-I is almost resonant |m| ~ |nq|. This is expected from ideal MHD in the proximity of rational surfaces. VMEC and MARS-...

  4. Characteristics and properties of metal aluminum thin films prepared by electron cyclotron resonance plasma-assisted atomic layer deposition technology

    Institute of Scientific and Technical Information of China (English)

    Xiong Yu-Qing; Li Xing-Cun; Chen Qiang; Lei Wen-Wen; Zhao Qiao; Sang Li-Jun; Liu Zhong-Wei; Wang Zheng-Duo; Yang Li-Zhen

    2012-01-01

    Metal aluminum (Al) thin films are prepared by 2450 MHz electron cyclotron resonance plasma-assisted atomic layer deposition on glass and p-Si substrates using trimethylaluminum as the precursor and hydrogen as the reductive gas.We focus our attention on the plasma source for the thin-film preparation and annealing of the as-deposited films relative to the surface square resistivity.The square resistivity of as-deposited Al films is greatly reduced after annealing and almost reaches the value of bulk metal.Through chemical and structural analysis,we conclude that the square resistivity is determined by neither the contaminant concentration nor the surface morphology,but by both the crystallinity and crystal size in this process.

  5. Improvement of efficiency and temperature control of induction heating vapor source on electron cyclotron resonance ion source.

    Science.gov (United States)

    Takenaka, T; Kiriyama, R; Muramatsu, M; Kitagawa, A; Uchida, T; Kurisu, Y; Nozaki, D; Yano, K; Yoshida, Y; Sato, F; Kato, Y; Iida, T

    2012-02-01

    An electron cyclotron resonance ion source (ECRIS) is used to generate multicharged ions for many kinds of the fields. We have developed an evaporator by using induction heating method that can generate pure vapor from solid state materials in ECRIS. We develop the new matching and protecting circuit by which we can precisely control the temperature of the induction heating evaporator. We can control the temperature within ±15 °C around 1400 °C under the operation pressure about 10(-4) Pa. We are able to use this evaporator for experiment of synthesizing process to need pure vapor under enough low pressure, e.g., experiment of generation of endohedral Fe-fullerene at the ECRIS.

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

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Youta, E-mail: imai@nf.eie.eng.osaka-u.ac.jp; Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

    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.

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

    CERN Document Server

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

    2016-01-01

    ABSTRACT 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.

  8. Electron cyclotron waves in the presence of parallel electric fields in the Earthś auroral plasma

    Science.gov (United States)

    Kumar, S.; Dixit, S. K.; Gwal, A. K.

    1997-01-01

    The electron cyclotron waves that originate at low altitudes (regions. Acknowledgements. The authors are grateful to Prof. D. J. Southwood (Imperial College, London), J. C. Samson (University of Alberta, Edmonton), L. J. Lanzerotti (AT&T Bell Laboratories), A. Wolfe (New York City Technical College) and to Dr. M. Vellante (University of LÁquila) for helpful discussions. They also thank Dr. A. Meloni (Istituto Nazionale di Geofisica, Roma) who made available geomagnetic field observations from LÁquila Geomagnetic Observatory. This research activity at LÁquila is supported by MURST (40% and 60% contracts) and by GIFCO/CNR. Topical Editor K.-H. Glaßmeier thanks C. Waters and S. Fujita for their help in evaluating this paper.-> Correspondence to :P. Francia->

  9. Design and characterization of a 32-channel heterodyne radiometer for electron cyclotron emission measurements on experimental advanced superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Han, X.; Liu, X.; Liu, Y., E-mail: liuyong@ipp.ac.cn; Li, E. Z.; Hu, L. Q.; Gao, X. [Institution of Plasma Physics, Chinese Academy of Sciences, P. O. Box 1126, Hefei, Anhui 230031 (China); Domier, C. W.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States)

    2014-07-15

    A 32-channel heterodyne radiometer has been developed for the measurement of electron cyclotron emission (ECE) on the experimental advanced superconducting tokamak (EAST). This system collects X-mode ECE radiation spanning a frequency range of 104–168 GHz, where the frequency coverage corresponds to a full radial coverage for the case with a toroidal magnetic field of 2.3 T. The frequency range is equally spaced every 2 GHz from 105.1 to 167.1 GHz with an RF bandwidth of ∼500 MHz and the video bandwidth can be switched among 50, 100, 200, and 400 kHz. Design objectives and characterization of the system are presented in this paper. Preliminary results for plasma operation are also presented.

  10. The effect of gas mixing and biased disc voltage on the preglow transient of electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O.; Toivanen, V.; Komppula, J.; Kalvas, T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae 40500 (Finland)

    2012-02-15

    The effect of gas mixing and biased disc voltage on the preglow of electron cyclotron resonance ion source plasma has been studied with the AECR-U type 14 GHz ion source. It was found that gas mixing has a significant effect on the preglow. The extracted transient beam currents and efficiency of the heavier species increase, while the currents and efficiency of the lighter species decrease when gas mixing is applied. The effect of the biased disc was found to be pronounced in continuous operation mode in comparison to preglow. The data provide information on the time scales of the plasma processes explaining the effects of gas mixing and biased disc. The results also have implications on production of radioactive ion beams in preglow mode for the proposed Beta Beam neutrino factory.

  11. Electron cyclotron resonance ion source plasma chamber studies using a network analyzer as a loaded cavity probe

    Energy Technology Data Exchange (ETDEWEB)

    Toivanen, V.; Tarvainen, O.; Kauppinen, J.; Komppula, J.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, Jyvaeskylae 40500 (Finland); Lyneis, C. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2012-02-15

    A method and first results utilizing a network analyzer as a loaded cavity probe to study the resonance properties of a plasma filled electron cyclotron resonance ion source (ECRIS) plasma chamber are presented. The loaded cavity measurements have been performed using a dual port technique, in which two separate waveguides were used simultaneously. One port was used to ignite and sustain the plasma with a microwave source operating around 11 GHz and the other was used to probe the cavity properties with the network analyzer using a frequency range around 14 GHz. The first results obtained with the JYFL 14 GHz ECRIS demonstrate that the presence of plasma has significant effects on the resonance properties of the cavity. With plasma the frequency dependent behavior is strongly damped and this trend strengthens with increasing microwave power.

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

    Science.gov (United States)

    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.

  13. Cyclotron resonant interactions in cosmic particle accelerators

    CERN Document Server

    Terasawa, T; 10.1007/s11214-012-9878-0

    2012-01-01

    A review is given for cyclotron resonant interactions in space plasmas. After giving a simple formulation for the test particle approach, illustrative examples for resonant interactions are given. It is shown that for obliquely propagating whistler waves, not only fundamental cyclotron resonance, but also other resonances, such as transit-time resonance, anomalous cyclotron resonance, higher-harmonic cyclotron resonance, and even subharmonic resonance can come into play. A few recent topics of cyclotron resonant interactions, such as electron injection in shocks, cyclotron resonant heating of solar wind heavy ions, and relativistic modifications, are also reviewed.

  14. Alfven cyclotron instability and ion cyclotron emission

    Energy Technology Data Exchange (ETDEWEB)

    Gorelenkov, N.N.; Cheng, C.Z.

    1995-07-01

    Two-dimensional solutions of compressional Alfven eigenmodes (CAE) are studied in the cold plasma approximation. For finite inverse aspect ratio tokamak plasmas the two-dimensional eigenmode envelope is localized at the low magnetic field side with the radial and poloidal localization on the order of a/{radical}m and a/(fourth root of m), respectively, where m is the dominant poloidal mode number. Charged fusion product driven Alfven Cyclotron Instability (ACI) of the compressional Alfven eigenmodes provides the explanation for the ion cyclotron emission (ICE) spectrum observed in tokamak experiments. The ACI is excited by fast charged fusion products via Doppler shifted cyclotron wave-particle resonances. The ion cyclotron and electron Landau dampings and fast particle instability drive are calculated perturbatively for deuterium-deuterium (DD) and deuterium-tritium (DT) plasmas. Near the plasma edge at the low field side the velocity distribution function of charged fusion products is localized in both pitch angle and velocity. The poloidal localization of the eigenmode enhances the ACI growth rates by a factor of {radical}m in comparison with the previous results without poloidal envelope. The thermal ion cyclotron damping determines that only modes with eigenfrequencies at multiples of the edge cyclotron frequency of the background ions can be easily excited and form an ICE spectrum similar to the experimental observations. Theoretical understanding is given for the results of TFTR DD and DT experiments with {upsilon}{sub {alpha}0}/{upsilon}{sub A} < 1 and JET experiments with {upsilon}{sub {alpha}0}/{upsilon}{sub A} > 1.

  15. Development of a compact thermal lithium atom beam source for measurements of electron velocity distribution function anisotropy in electron cyclotron resonance plasmas.

    Science.gov (United States)

    Nishioka, T; Shikama, T; Nagamizo, S; Fujii, K; Zushi, H; Uchida, M; Iwamae, A; Tanaka, H; Maekawa, T; Hasuo, M

    2013-07-01

    The anisotropy of the electron velocity distribution function (EVDF) in plasmas can be deduced from the polarization of emissions induced by anisotropic electron-impact excitation. In this paper, we develop a compact thermal lithium atom beam source for spatially resolved measurements of the EVDF anisotropy in electron cyclotron resonance (ECR) plasmas. The beam system is designed such that the ejected beam has a slab shape, and the beam direction is variable. The divergence and flux of the beam are evaluated by experiments and calculations. The developed beam system is installed in an ECR plasma device with a cusp magnetic field, and the LiI 2s-2p emission (670.8 nm) is observed in low-pressure helium plasma. The two-dimensional distributions of the degree and direction of the polarization in the LiI emission are measured by a polarization imaging system. The evaluated polarization distribution suggests the spatial variation of the EVDF anisotropy.

  16. Plasma and cyclotron frequency effects on output power of the plasma wave-pumped free-electron lasers

    Science.gov (United States)

    Zolghadr, S. H.; Jafari, S.; Raghavi, A.

    2016-05-01

    Significant progress has been made employing plasmas in the free-electron lasers (FELs) interaction region. In this regard, we study the output power and saturation length of the plasma whistler wave-pumped FEL in a magnetized plasma channel. The small wavelength of the whistler wave (in sub-μm range) in plasma allows obtaining higher radiation frequency than conventional wiggler FELs. This configuration has a higher tunability by adjusting the plasma density relative to the conventional ones. A set of coupled nonlinear differential equations is employed which governs on the self-consistent evolution of an electromagnetic wave. The electron bunching process of the whistler-pumped FEL has been investigated numerically. The result reveals that for a long wiggler length, the bunching factor can appreciably change as the electron beam propagates through the wiggler. The effects of plasma frequency (or plasma density) and cyclotron frequency on the output power and saturation length have been studied. Simulation results indicate that with increasing the plasma frequency, the power increases and the saturation length decreases. In addition, when density of background plasma is higher than the electron beam density (i.e., for a dense plasma channel), the plasma effects are more pronounced and the FEL-power is significantly high. It is also found that with increasing the strength of the external magnetic field frequency, the power decreases and the saturation length increases, noticeably.

  17. Influence of wave frequency variation on anomalous cyclotron resonance interaction of energetic electrons with finite amplitutude ducted whistler-mode wave

    CERN Document Server

    Erokhin, N S; Rycroft, M J; Nunn, D G

    1996-01-01

    The influence of wave frequency variation on the anomalous cyclotron resonance $\\omega=\\omega_{Be}+kv_{\\|}$ interaction (ACRI) of energetic electrons with a ducted finite amplitude whistler-mode wave propagating through the so-called transient plasma layer (TPL) in the magnetosphere or in the ionosphere is studied both analytically and numerically. The anomalous cyclotron resonance interaction takes place in the case when the whistler-mode wave amplitude $B_{W}$ is consistent with the gradient of magnetic field interacting energetic electrons (synchronous particles) is determined. The efficiencies of both the pitch-angle scattering of resonant electrons and their transverse acceleration are studied and the efficiencies dependence on the magnitude and sign of the wave frequency drift is considered. It has been shown that in the case of ACRI occuring under conditions relevant to VLF-emission in the magnetosphere, the energy and pitch-angle changes of synchronous electrons may be enchanced by a factor $10^2 \\div...

  18. Efficiency enhancement of slow-wave electron-cyclotron maser by a second-order shaping of the magnetic field in the low-gain limit

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Si-Jia; Zhang, Yu-Fei; Wang, Kang [School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Yong-Ming [Information Science and Engineering College, XinJiang University, Urumqi XinJiang 830046 (China); Jing, Jian, E-mail: jingjian@mail.buct.edu.cn [School of Science, Beijing University of Chemical Technology, Beijing 100029 (China)

    2017-03-15

    Based on the anomalous Doppler effect, we put forward a proposal to enhance the conversion efficiency of the slow-wave electron cyclotron masers (ECM) under the resonance condition. Compared with previous studies, we add a second-order shaping term in the guild magnetic field. Theoretical analyses and numerical calculations show that it can enhance the conversion efficiency in the low-gain limit. The case of the initial velocity spread of electrons satisfying the Gaussian distribution is also analysed numerically.

  19. Inductively Coupled Plasma and Electron Cyclotron Resonance Plasma Etching of InGaAlP Compound Semiconductor System

    Energy Technology Data Exchange (ETDEWEB)

    Abernathy, C.R.; Hobson, W.S.; Hong, J.; Lambers, E.S.; Pearton, S.J.; Shul, R.J.

    1998-11-04

    Current and future generations of sophisticated compound semiconductor devices require the ability for submicron scale patterning. The situation is being complicated since some of the new devices are based on a wider diversity of materials to be etched. Conventional IUE (Reactive Ion Etching) has been prevalent across the industry so far, but has limitations for materials with high bond strengths or multiple elements. IrI this paper, we suggest high density plasmas such as ECR (Electron Cyclotron Resonance) and ICP (Inductively Coupled Plasma), for the etching of ternary compound semiconductors (InGaP, AIInP, AlGaP) which are employed for electronic devices like heterojunction bipolar transistors (HBTs) or high electron mobility transistors (HEMTs), and photonic devices such as light-emitting diodes (LEDs) and lasers. High density plasma sources, opeiating at lower pressure, are expected to meet target goals determined in terms of etch rate, surface morphology, surface stoichiometry, selectivity, etc. The etching mechanisms, which are described in this paper, can also be applied to other III-V (GaAs-based, InP-based) as well as III-Nitride since the InGaAIP system shares many of the same properties.

  20. ORNL TNS program: microwave start-up of tokamak plasmas near electron cyclotron and upper hybrid resonances

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Y. K.M.; Borowski, S. K.

    1977-12-01

    The scenario of toroidal plasma start-up with microwave initiation and heating near the electron cyclotron frequency is suggested and examined here. We assume microwave irradiation from the high field side and an anomalously large absorption of the extraordinary waves near the upper hybrid resonance. The dominant electron energy losses are assumed to be due to magnetic field curvature and parallel drifts, ionization of neutrals, cooling by ions, and radiation by low Z impurities. It is shown by particle and energy balance considerations that electron temperatures around 250 eV and densities of 10/sup 12/ to 10/sup 13/ cm/sup -3/ can be maintained, at least in a narrow region near the upper hybrid resonance, with modest microwave powers in the Impurity Study Experiment (ISX) (120 kW at 28 GHz) and The Next Step (TNS) (0.57 MW at 120 GHz). The loop voltages required for start-up from these initial plasmas are also estimated. It is shown that the loop voltage can be reduced by a factor of five to ten from that for unassisted start-up without an increase in the resistive loss in volt-seconds. If this reduction in loop voltage is verified in the ISX experiments, substantial savings in the cost of power supplies for the ohmic heating (OH) and equilibrium field (EF) coils can be realized in future large tokamaks.

  1. Broad wavenumber turbulence and transport during Ohmic and electron cyclotron heating in the DIII-D tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, T L [Physics and Astronomy Department, University of California-Los Angeles, Los Angeles, CA 90025 (United States); Peebles, W A [Physics and Astronomy Department, University of California-Los Angeles, Los Angeles, CA 90025 (United States); DeBoo, J C [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Prater, R [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Kinsey, J E [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Staebler, G M [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Candy, J [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Austin, M E [University of Texas-Austin, Austin, TX 78712 (United States); Bravenec, R V [University of Texas-Austin, Austin, TX 78712 (United States); Burrell, K H [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); De Grassie, J S [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Doyle, E J [Physics and Astronomy Department, University of California-Los Angeles, Los Angeles, CA 90025 (United States); Gohil, P; Greenfield, C M; Groebner, R J; Lohr, J [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Makowski, M A [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Nguyen, X V [Physics and Astronomy Department, University of California-Los Angeles, Los Angeles, CA 90025 (United States); Petty, C C [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Solomon, W M [Princeton Plasma Physics Laboratory, Princeton, NJ 08543-0451 (United States); John, H E St; Zeeland, M A Van [General Atomics, PO Box 85608, San Diego, CA 92186-5608 (United States); Wang, G.; Zeng, L [Physics and Astronomy Department, University of California-Los Angeles, Los Angeles, CA 90025 (United States)

    2007-12-15

    The response of plasma parameters and broad wavenumber turbulence (1-39 cm{sup -1}, k{rho}{sub s} = 0.1-10, relevant to ion temperature gradient, trapped electron mode and electron temperature gradient mode turbulence, here {rho}{sub s} = ion gyroradius) to auxiliary electron cyclotron heating (ECH) is reported on. One fluid thermal fluxes and diffusivities increase appreciably with ECH. Significant changes to the density fluctuations over the full range of measured wavenumbers are observed, with an increase for lower wavenumbers and a more spatially complicated response at high k. Spatially resolved high k measurements (k = 39 cm{sup -1}, k{rho}{sub s} = 4-10) show a varying response to ECH, with n-bar decreasing at r/a = 0.35 and increasing at r/a = 0.6 and 1. These variations were found to have a positive correlation with {nabla}T{sub e} evaluated at nearby locations, consistent with a {nabla}T{sub e} drive. Comparison of the changes in high k fluctuation levels with linear gyrokinetic growth rates show qualitative agreement at the innermost location, r/a = 0.35 and disagreement at r/a = 0.6.

  2. Electron cyclotron maser emission mode coupling to the z-mode on a longitudinal density gradient in the context of solar type III bursts

    CERN Document Server

    Pechhacker, Roman

    2012-01-01

    A beam of super-thermal, hot electrons was injected into maxwellian plasma with a density gradient along a magnetic field line. 1.5D particle-in-cell simulations were carried out which established that the EM emission is produced by the perpendicular component of the beam injection momentum. The beam has a positive slope in the distribution function in perpendicular momentum phase space, which is the characteristic feature of a cyclotron maser. The cyclotron maser in the overdense plasma generates emission at the electron cyclotron frequency. The frequencies of generated waves were too low to propagate away from the injection region, hence the wavelet transform shows a pulsating wave generation and decay process. The intensity pulsation frequency is twice the relativistic cyclotron frequency. Eventually, a stable wave packet formed and could mode couple on the density gradient to reach frequencies of the order of the plasma frequency, that allowed for propagation. The emitted wave is likely to be a z-mode wav...

  3. Low-noise AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor recessed by electron cyclotron resonance plasma etching

    CERN Document Server

    Lee, J H; Lee, C W; Yoon, H S; Park, B S; Park, C S

    1999-01-01

    GaAs pseudomorphic high electron mobility transistor recessed by electron cyclotron resonance (ECR) plasma etching have been investigated. We used a BCl sub 3 /SF sub 6 gas mixture to implement the gate recess process. We obtained a uniformity of the threshold voltage to within 50 mV in 3-inch wafers. The GaAs PHEMTs with a 0.2-mu m gate length recessed by the ECR plasma exhibited a minimum noise figure (NF sub m sub i sub n) as low as 0.26 dB with an associated gain (G sub a) of 13 dB at 12 GHz. At 18 GHz, the NF sub m sub i sub n was 0.47 dB with a Ga of 11.66 dB. These results suggest that the ECR plasma etching process reported here is suitable as a manufacturing process for gate recess of a GaAs PHEMT.

  4. VIPRE-W / MEFISTO-T - A mechanistic tool for transient prediction of dryout in BWR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Adamsson, C., E-mail: carl.adamsson@psi.ch [Westinhouse Electric Sweden, Vasteras (Sweden); Paul Scherrer Institut, Villigen (Switzerland); Le Corre, J-M., E-mail: lecorrjm@westinghouse.com [Westinhouse Electric Sweden, Vasteras (Sweden)

    2011-07-01

    The VIPRE-W/MEFISTO-T code package constitutes a simplified approach to sub-channel film-flow analysis whereby the transport equations for the liquid films are decoupled from each other. The approach allows fast and robust simulation with high axial resolution of realistic BWR transients. It has previously been shown that a steady-state version of the model agrees well with dryout measurements in full-scale fuel assembly mock-ups performed at the Westinghouse FRIGG loop. In this paper, we present validation of the transient version of the code with around 300 transient dryout experiments from the same loop. The transients involve realistic variations of flow and power and three different axial power distributions at conditions typical for BWR operation. The results from the film-flow analysis show high precision in the dryout prediction but a hitherto unexplained bias that reduces the accuracy. (author)

  5. A mode converter to generate a Gaussian-like mode for injection into the VENUS electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lyneis, C., E-mail: CMLyneis@lbl.gov; Benitez, J.; Hodgkinson, A.; Strohmeier, M.; Todd, D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Plaum, B. [Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie (IGVP), Stuttgart (Germany); Thuillier, T. [Laboratoire de Physique Subatomique et de Cosmologie, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des martyrs 38026 Grenoble cedex (France)

    2014-02-15

    A number of superconducting electron cyclotron resonance (ECR) ion sources use gyrotrons at either 24 or 28 GHz for ECR heating. In these systems, the microwave power is launched into the plasma using the TE{sub 01} circular waveguide mode. This is fundamentally different and may be less efficient than the typical rectangular, linearly polarized TE{sub 10} mode used for launching waves at lower frequencies. To improve the 28 GHz microwave coupling in VENUS, a TE{sub 01}-HE{sub 11} mode conversion system has been built to test launching HE{sub 11} microwave power into the plasma chamber. The HE{sub 11} mode is a quasi-Gaussian, linearly polarized mode, which should couple strongly to the plasma electrons. The mode conversion is done in two steps. First, a 0.66 m long “snake” converts the TE{sub 01} mode to the TE{sub 11} mode. Second, a corrugated circular waveguide excites the HE{sub 11} mode, which is launched directly into the plasma chamber. The design concept draws on the development of similar devices used in tokamaks and stellerators. The first tests of the new coupling system are described below.

  6. Broadband measurement of electron cyclotron emission in TFTR using a quasioptical light collection system and a polarizing Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; Diesso, M.; McCarthy, M.P.; Montague, J.; Rocco, R.

    1988-10-01

    For the past four years, a Fourier transform spectrometer diagnostic system, employing a fast-scanning polarizing Michelson interferometer (FMI), has been operating on the TFTR tokamak at the Princeton Plasma Physics Laboratory. It is used to measure the electron cyclotron emission (ECE) spectrum over the range 2.5--18 cm/sup -1/ (75--540 GHz), with a resolution of 0.123 cm/sup -1/ (3.7 GHz), at a rate of 72 spectra per second. The quasioptical system for collecting the light and transporting it through the interferometer to the detector has been designed using the concepts of both Gaussian and geometrical optics. The commercial FMI was custom made for this project and is the state of the art for this type of specialized instrument. The diagnostic system is described and an error propagation analysis of the absolute calibration process is given. Examples of ECE spectra measured in two polarization directions are given and electron temperature profiles derived from each of them are compared.

  7. Electron cyclotron harmonic waves observed by the AMPTE-IRM plasma wave experiment following a lithium release in the solar wind

    Science.gov (United States)

    Roeder, J. L.; Koons, H. C.; Holzworth, R. H.; Anderson, R. R.; Bauer, O. H.

    1987-01-01

    An unexpected occurrence following the second lithium release by the AMPTE-IRM spacecraft in the solar wind on September 20, 1984, was the appearance of electron cyclotron harmonic emissions. These emissions began about 50 s after the release and continued for several minutes. Narrow-band emissions polarized perpendicular to the magnetic field with amplitudes of approximately 0.00001 V/m were observed in each of the first five harmonic bands. The diffuse emissions extended from below the lowest measured frequency channel to above the highest narrow-band emission with a maximum below the electron cyclotron frequency. It will be shown that these observations are inconsistent with their generation by several ion beam instabilities.

  8. Parametric evaluation of electron cyclotron resonance deposited SiO{sub 2} using a multicusp plasma applicator

    Energy Technology Data Exchange (ETDEWEB)

    Buckle, K.A.; Pastor, K. [Univ. of South Florida, Tampa, FL (United States); Constantine, C.; Johnson, D. [Plasma-Therm Industrial Products, Inc., St. Petersburg, FL (United States)

    1992-05-01

    Plasma deposition of SiO{sub 2} on silicon substrates in a microwave (2.45 GHz) electron cyclotron resonance N{sub 2}O/SiH{sub 4}/He discharge has been investigated as a function of radio frequency (13.56 MHz) self-biasing of the sample, pressure, and microwave power, substrate temperature, and gas mixture. Deposition rates between 30 and 90 nm/min have been observed with quality films over a range of parameter combinations. The films have been analyzed for thickness and index of refraction by ellipsometry and for chemical structure by Fourier transform infrared spectroscopy. The deposition process yielded films with virtually no Si-H, N-H, or Si-N bonding groups and only traces of OH bonds. Analysis of the Si-O-Si stretching peak reveals a film quality which compares favorably with good quality thermal oxides grown at much higher substrate bulk temperatures. Also, the relative insensitivity to the He content of the gas mixture indicates the surface chemistry of this process is fundamentally different from previously reported plasma enhanced chemical vapor deposition processes. 9 refs., 9 figs.

  9. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

    Science.gov (United States)

    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.

  10. Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion source.

    Science.gov (United States)

    Kutsumi, Osamu; Kato, Yushi; Matsui, Yuuki; Kitagawa, Atsushi; Muramatsu, Masayuki; Uchida, Takashi; Yoshida, Yoshikazu; Sato, Fuminobu; Iida, Toshiyuki

    2010-02-01

    Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply. We conduct experiment to investigate the reproducibility and stability in the operation and heating efficiency. IH evaporator produces pure material vapor because materials directly heated by eddy currents have no contact with insulated materials, which are usually impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10(-4)-10(-3) Pa. We measure the temperature of the vaporized materials with different shapes, and compare them with the result of modeling. We estimate the efficiency of the IH vapor source. We are aiming at the evaporator's higher melting point material than that of iron.

  11. Progress of a room temperature electron cyclotron resonance ion source using evaporative cooling technology at Institute of Modern Physics

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W., E-mail: luwang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, B.; Guo, S. Q.; Cao, R.; Ruan, L. [Institute of Electrical Engineering, CAS, Beijing 100190 (China); Zhang, X. Z.; Sun, L. T.; Feng, Y. C.; Ma, B. H.; Zhao, H. W. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73000 (China)

    2014-02-15

    A new room temperature ECR ion source, Lanzhou Electron Cyclotron Resonance ion source No. 4 (LECR4, previously named DRAGON), is under intense construction at Institute of Modern Physics. LECR4 is designed to operate with 18 GHz microwave frequency. The maximum axial magnetic fields are 2.3 T at injection and 1.3 T at extraction, and the radial field at the plasma chamber wall of 76 mm inner diameter is 1.0–1.2 T. One of the unique features for LECR4 is that its axial solenoids are winded with solid square copper wires which are immersed in a kind of special evaporative cooling medium for cooling purpose. Till now, a prototype of the cooling system has been successfully constructed and tested, which has demonstrated that the cooling efficiency of the designed system could meet the requirements of LECR4 under the routine operation conditions. All the main components of the ion source have been completed. Assembly and commissioning is ongoing. The latest developments and test results will be presented in this paper.

  12. Development of a high power wideband polarizer for electron cyclotron current drive system in JT-60SA

    Energy Technology Data Exchange (ETDEWEB)

    Saigusa, Mikio, E-mail: saigusa@mx.ibaraki.ac.jp [Ibaraki University, Hitachi, Ibaraki 316-8511 (Japan); Oyama, Gaku; Matsubara, Fumiaki; Takii, Keita; Sai, Takuma [Ibaraki University, Hitachi, Ibaraki 316-8511 (Japan); Kobayashi, Takayuki; Moriyama, Shinichi [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)

    2015-10-15

    Highlights: • We developed a new wideband polarizer for JT-60SA ECCD system. • The wideband polarizer is optimized for dual frequency gyrotrons (110 and 138 GHz) in JT-60SA. • The wideband polarization properties were verified at cold tests. • The preliminary high power tests have been carried out at 0.25 MW, 3 s at 110 GHz. - Abstract: A wideband polarizer consisting of a polarization twister and a circular polarizer has been developed for an electron cyclotron current driving system in JT-60SA, where the output frequencies of a dual frequency gyrotron for JT-60SA are 110 and 138 GHz. The groove depths are optimized for the dual frequencies by numerical simulations using a FDTD method and cold test results. The polarization properties of a mock-up polarizer are measured at the dual frequencies in cold tests. The cold test results suggest that all practical polarizations for ECCD experiments can be achieved at the dual frequencies. The prototype polarization twister has been tested up to 0.25 MW during 3 s at the frequency of 110 GHz.

  13. Upgrade of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN

    Science.gov (United States)

    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.

  14. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap.

    Science.gov (United States)

    Nikolaev, A G; Savkin, K P; Oks, E M; Vizir, A V; Yushkov, G Yu; Vodopyanov, A V; Izotov, I V; Mansfeld, D A

    2012-02-01

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent "minimum-B" structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap--axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 μs) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  15. Photoconducting ultraviolet detectors based on GaN films grown by electron cyclotron resonance molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Misra, M.; Shah, K.S. [Radiation Monitoring Devices, Inc., Watertown, MA (United States); Moustakas, T.D.; Vaudo, R.P.; Singh, R. [Boston Univ., MA (United States). Molecular Beam Epitaxy Lab.

    1995-08-01

    We report for the first time, fabrication of photoconducting UV detectors made from GaN films grown by molecular beam epitaxy. Semi-instilating GaN films were grown by the method of electron cyclotron resonance microwave plasma-assisted molecular beam epitaxy (ECR-MBE). Photoconductive devices with interdigitated electrodes were fabricated and their photoconducting properties were investigated. In this paper we report on the performance of the detectors in terms of UV responsivity, gain-quantum efficiency product, spectral response and response time. We have measured responsivity of 125A/W and gain-quantum efficiency product of 600 at 254nm and 25V. The response time was measured to be on the order of 20ns for our detectors, corresponding to a bandwidth of 25Mhz. The spectral response showed a sharp long-wavelength cutoff at 365nm, and remained constant in the 200nm to 365nm range. The response of the detectors to low-energy x-rays was measured and found to be linear for x-rays with energies ranging from 60kVp to 90kVp.

  16. Progress of a room temperature electron cyclotron resonance ion source using evaporative cooling technology at Institute of Modern Physics.

    Science.gov (United States)

    Lu, W; Xiong, B; Zhang, X Z; Sun, L T; Feng, Y C; Ma, B H; Guo, S Q; Cao, R; Ruan, L; Zhao, H W

    2014-02-01

    A new room temperature ECR ion source, Lanzhou Electron Cyclotron Resonance ion source No. 4 (LECR4, previously named DRAGON), is under intense construction at Institute of Modern Physics. LECR4 is designed to operate with 18 GHz microwave frequency. The maximum axial magnetic fields are 2.3 T at injection and 1.3 T at extraction, and the radial field at the plasma chamber wall of 76 mm inner diameter is 1.0-1.2 T. One of the unique features for LECR4 is that its axial solenoids are winded with solid square copper wires which are immersed in a kind of special evaporative cooling medium for cooling purpose. Till now, a prototype of the cooling system has been successfully constructed and tested, which has demonstrated that the cooling efficiency of the designed system could meet the requirements of LECR4 under the routine operation conditions. All the main components of the ion source have been completed. Assembly and commissioning is ongoing. The latest developments and test results will be presented in this paper.

  17. Diagnostics of a charge breeder electron cyclotron resonance ion source helium plasma with the injection of ^{23}Na^{1+} ions

    Directory of Open Access Journals (Sweden)

    O. Tarvainen

    2016-05-01

    Full Text Available This work describes the utilization of an injected ^{23}Na^{1+} 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 10^{11}  cm^{-3} or higher. The experimental results are compared to simulations of the ^{23}Na^{1+} 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.

  18. Diffuse auroral electron scattering by electrostatic electron cyclotron harmonic (ECH) waves and electromagnetic whistler-mode chorus in the inner magnetosphere

    Science.gov (United States)

    Ni, B.; Thorne, R. M.; Horne, R. B.; Meredith, N. P.; Shprits, Y.; Chen, L.

    2009-12-01

    The diffuse aurora constitutes one of the most important loss processes of plasma sheet electrons, supplying the majority of ionizing energy input into the high-latitude region during conditions of both low and high solar wind driving. It is generally agreed that wave-particle interactions, including scattering losses by electrostatic electron cyclotron harmonic (ECH) waves and electromagnetic whistler-mode chorus waves, play an essential role in the occurrence of the diffuse aurora. However, the precise role of each wave mode has remained a source of controversy for many years. To quantify the scattering effects of these two wave modes, we have improved the methodology for computation of quasi-linear diffusion coefficients and adopted statistical wave models based on the survey of ECH waves and chorus using the entire CRRES database. Our results demonstrate that, whistler-mode chorus is the dominant mechanism for loss of injected plasma sheet electrons from the inner magnetosphere (4 1 keV, suggesting rather minor contributions from ECH waves to the diffuse auroral precipitation. Our results also show that the scattering effects on plasma sheet electrons by the waves are strongly dependent on the level of geomagnetic activity.

  19. Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. II. Electron Heating Efficiency as a Function of Flow Conditions

    CERN Document Server

    Sironi, Lorenzo

    2014-01-01

    In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the electrons. This paradigm assumes that Coulomb collisions are the only channel for transferring the ion energy to the electrons. In this work, the second of a series, we assess the efficiency of electron heating by ion velocity-space instabilities in collisionless accretion flows. The instabilities are seeded by the pressure anisotropy induced by magnetic field amplification, coupled to the adiabatic invariance of the particle magnetic moments. Using two-dimensional (2D) particle-in-cell (PIC) simulations, we showed in Paper I that if the electron-to-ion temperature ratio is < 0.2, the ion cyclotron instability is the dominant mode for values of ion beta_i ~ 5-30 (here, beta_i is the ratio of ion thermal pressure to magnetic pressure), as appropriate for the midplane of low-lumin...

  20. Relativistic down-shift frequency effect on the application of electron cyclotron emission measurements to JT-60U tokamak plasmas. Second harmonics

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masayasu; Isei, Nobuaki; Ishida, Sinichi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1995-11-01

    Effect of relativistic frequency down-shift on the determination of the electron temperature profile from electron cyclotron emission(ECE) in JT-60U tokamak plasmas is studied. The radial shift of the electron temperature profile due to the effects is not negligible, compared with the spatial resolution of ECE measurement systems of JT-60U. Therefore it is necessary to correct the effect for precise measurement of the electron temperature profile. Dependencies of the shifted frequency on the electron density, electron temperature and toroidal magnetic field are studied for the uniform electron density and parabolic electron temperature profile in JT-60U. It is revealed to be necessary for the estimation of shift due to the relativistic down-shift frequency to take into account of the optical thickness. (author).

  1. Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Panitzsch, Lauri

    2013-02-08

    The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet ({approx}45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to

  2. A double-layer based model of ion confinement in electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, D., E-mail: davidmascali@lns.infn.it; Neri, L.; Celona, L.; Castro, G.; Gammino, S.; Ciavola, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Torrisi, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Università Mediterranea di Reggio Calabria, Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile, Via Graziella, I-89100 Reggio Calabria (Italy); Sorbello, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Catania, Dipartimento di Ingegneria Elettrica Elettronica ed Informatica, Viale Andrea Doria 6, 95125 Catania (Italy)

    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.

  3. Electron cyclotron waves transmission: new approach for the characterization of electron distribution functions in Tokamak hot plasmas; La transmission d`ondes cyclotroniques electroniques: une approche nouvelle pour caracteriser les fonctions de distribution electronique des plasmas chauds de Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Michelot, Y.

    1995-10-01

    Fast electrons are one of the basic ingredients of plasma operations in many existing thermonuclear fusion research devices. However, the understanding of fast electrons dynamics during creation and sustainment of the superthermal electrons tail is far for being satisfactory. For this reason, the Electron Cyclotron Transmission (ECT) diagnostic was implemented on Tore Supra tokamak. It consists on a microwave transmission system installed on a vertical chord crossing the plasma center and working in the frequency range 77-109 GHz. Variations of the wave amplitude during the propagation across the plasma may be due to refraction and resonant absorption. For the ECT, the most common manifestation of refraction is a reduction of the received power density with respect to the signal detected in vacuum, due to the spreading and deflection of the wave beam. Wave absorption is observed in the vicinity of the electron cyclotron harmonics and may be due both to thermal plasma and to superthermal electron tails. It has a characteristic frequency dependence due to the relativistic mass variation in the wave-electron resonance condition. This thesis presents the first measurements of: the extraordinary mode optical depth at the third harmonics, the electron temperature from the width of a cyclotron absorption line and the relaxation times of the electron distribution during lower hybrid current drive from the ordinary mode spectral superthermal absorption line at the first harmonic. (J.S.). 175 refs., 110 figs., 9 tabs., 3 annexes.

  4. Operation of the CAPRICE electron cyclotron resonance ion source applying frequency tuning and double frequency heating.

    Science.gov (United States)

    Maimone, F; Tinschert, K; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P

    2012-02-01

    The properties of the electromagnetic waves heating the electrons of the ECR ion sources (ECRIS) plasma affect the features of the extracted ion beams such as the emittance, the shape, and the current, in particular for higher charge states. The electron heating methods such as the frequency tuning effect and the double frequency heating are widely used for enhancing the performances of ECRIS or even for the routine operation during the beam production. In order to better investigate these effects the CAPRICE ECRIS has been operated using these techniques. The ion beam properties for highly charged ions have been measured with beam diagnostic tools. The reason of the observed variations of this performance can be related to the different electromagnetic field patterns, which are changing inside the plasma chamber when the frequency is varying.

  5. High electronegativity multi-dipolar electron cyclotron resonance plasma source for etching by negative ions

    DEFF Research Database (Denmark)

    Stamate, Eugen; Draghici, M.

    2012-01-01

    A large area plasma source based on 12 multi-dipolar ECR plasma cells arranged in a 3 x 4 matrix configuration was built and optimized for silicon etching by negative ions. The density ratio of negative ions to electrons has exceeded 300 in Ar/SF6 gas mixture when a magnetic filter was used...... to reduce the electron temperature to about 1.2 eV. Mass spectrometry and electrostatic probe were used for plasma diagnostics. The new source is free of density jumps and instabilities and shows a very good stability for plasma potential, and the dominant negative ion species is F-. The magnetic field...... in plasma volume is negligible and there is no contamination by filaments. The etching rate by negative ions measured in Ar/SF6/O-2 mixtures was almost similar with that by positive ions reaching 700 nm/min. (C) 2012 American Institute of Physics...

  6. Pitch angle scattering of relativistic electrons near electromagnetic ion cyclotron resonances in diverging magnetic fields

    Science.gov (United States)

    Eliasson, B.; Papadopoulos, K.

    2017-10-01

    A theoretical study of the propagation of left-hand polarized shear Alfvén waves in spatially decreasing magnetic field geometries near the EMIC resonance, including the spectrum and amplitude of the mode converted EMIC waves and the pitch angle scattering of relativistic electrons transiting the resonant region, is presented. The objective of the paper is to motivate an experimental study of the subject using the UCLA LAPD chamber. The results are relevant in exploring the possibility that shear Alfvén waves strategically injected into the radiation belts using either ionospheric heating from ground based RF transmitters or injected by transmitters based on space platforms can enhance the precipitation rate of trapped relativistic electrons. Effects of multi-ionic composition are also investigated.

  7. Effect of Oblique Electromagnetic Ion Cyclotron Waves on Relativistic Electron Scattering: CRRES Based Calculation

    Science.gov (United States)

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

    2007-01-01

    We consider the effect of oblique EMIC waves on relativistic electron scattering in the outer radiation belt using simultaneous observations of plasma and wave parameters from CRRES. The main findings can be s ummarized as follows: 1. In 1comparison with field-aligned waves, int ermediate and highly oblique distributions decrease the range of pitc h-angles subject to diffusion, and reduce the local scattering rate b y an order of magnitude at pitch-angles where the principle absolute value of n = 1 resonances operate. Oblique waves allow the absolute va lue of n > 1 resonances to operate, extending the range of local pitc h-angle diffusion down to the loss cone, and increasing the diffusion at lower pitch angles by orders of magnitude; 2. The local diffusion coefficients derived from CRRES data are qualitatively similar to the local results obtained for prescribed plasma/wave parameters. Conseq uently, it is likely that the bounce-averaged diffusion coefficients, if estimated from concurrent data, will exhibit the dependencies similar to those we found for model calculations; 3. In comparison with f ield-aligned waves, intermediate and highly oblique waves decrease th e bounce-averaged scattering rate near the edge of the equatorial lo ss cone by orders of magnitude if the electron energy does not excee d a threshold (approximately equal to 2 - 5 MeV) depending on specified plasma and/or wave parameters; 4. For greater electron energies_ ob lique waves operating the absolute value of n > 1 resonances are more effective and provide the same bounce_averaged diffusion rate near the loss cone as fiel_aligned waves do.

  8. A free-electron laser for cyclotron resonant heating in magnetic fusion reactors

    Science.gov (United States)

    Freund, H. P.; Read, M. E.; Jackson, R. H.; Pershing, D. E.; Taccetti, J. M.

    1995-05-01

    A G-band free-electron laser designed for plasma heating is described using a coaxial hybrid iron (CHI) wiggler formed by insertion into a solenoid of a central rod and an outer ring of alternating ferrite and nonferrite spacers positioned so that the central ferrite (nonferrite) spacers are opposite the outer nonferrite (ferrite) spacers. The CHI wiggler provides for enhanced beam focusing and the ability to handle intense beams and high-power continuous wave radiation. Simulations indicate that a power/efficiency of 3.5 MW/13% are possible using a 690 kV/40 A beam. No beam loss was found in simulation.

  9. Intense beam production of highly charged heavy ions by the superconducting electron cyclotron resonance ion source SECRAL.

    Science.gov (United States)

    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.

  10. The effect of plasma electrode collar structure on the performance of the JYFL 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Toivanen, V., E-mail: ville.toivanen@jyu.fi; Tarvainen, O.; Komppula, J.; Koivisto, H.

    2013-10-21

    The influence of a so-called collar structure on the performance of the JYFL 14 GHz electron cyclotron resonance ion source (ECRIS) has been studied experimentally at the Department of Physics, University of Jyväskylä (JYFL). The collar is a cylindrical structure extruding inwards from the plasma electrode. The collar length was varied between 5 and 60 mm. For some ion species a moderate performance improvement was achieved in terms of extracted beam current and transverse emittance up to 30 mm collar length. Longer collars resulted in a substantial performance decrease. Different collar materials, i.e. nonmagnetic stainless steel, aluminum and Al{sub 2}O{sub 3}, and a wide range of ion species for elements ranging from {sup 14}N to {sup 82}Kr were studied. No clear material or ion species dependent behavior was observed. The experiments suggest that the extracted ions originate from a plasma volume which is at a considerable axial distance from the extraction aperture. Furthermore it is concluded that a substantial space exists surrounding the collar that could be utilized for applying novel techniques to boost the performance of ECR ion sources. -- Highlights: • Effects of a so-called collar structure studied with AECR-U type ion source. • Moderate improvement to source performance when collar is not too long. • No clear collar material or ion species dependent behavior is observed. • Results suggest that the extracted ions originate from plasma volume far from extraction. • Results suggest that the space around extraction aperture could be utilized productively.

  11. Medical cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A P

    1976-01-01

    Cyclotrons as tools for therapy and for the production of radionuclides for use in nuclear medicine have been extensively reviewed in the literature. The current world status with respect to cyclotrons used primarily for research, development and application in nuclear medicine is reviewed here in the context of geographical distribution and type of use, presently available commercial types, machine characteristics and trends. Aspects of design requirements from a user perspective such as machine, beam and target characteristics are covered. Some special problems concerning many factors which can lead to effective production of the desired radionuclide or product are considered in light of machine characteristics. Consideration is also given to future directions for accelerators in nuclear medicine.

  12. Development of a 2 MW CW Waterload for Electron Cyclotron Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    R. Lawrence,Ives; Maxwell Mizuhara; George Collins; Jeffrey Neilson; Philipp Borchard

    2012-11-09

    Calabazas Creek Research, Inc. developed a load capable of continuously dissipating 2 MW of RF power from gyrotrons. The input uses HE11 corrugated waveguide and a rotating launcher to uniformly disperse the power over the lossy surfaces in the load. This builds on experience with a previous load designed to dissipate 1 MW of continuous RF power. The 2 MW load uses more advanced RF dispersion to double the capability in the same size device as the 1 MW load. The new load reduces reflected power from the load to significantly less than 1 %. This eliminates requirements for a preload to capture reflected power. The program updated control electronics that provides all required interlocks for operation and measurement of peak and average power. The program developed two version of the load. The initial version used primarily anodized aluminum to reduce weight and cost. The second version used copper and stainless steel to meet specifications for the ITER reactor currently under construction in France. Tests of the new load at the Japanese Atomic Energy Agency confirmed operation of the load to a power level of 1 MW, which is the highest power currently available for testing the load. Additional tests will be performed at General Atomics in spring 2013. The U.S. ITER organization will test the copper/stainless steel version of the load in December 2012 or early in 2013. Both loads are currently being marketed worldwide.

  13. Study of microwave components for an electron cyclotron resonance source: Simulations and performance

    Indian Academy of Sciences (India)

    S K Jain; Deepak Sharma; V K Senecha; P A Naik; P R Hannurkar

    2014-08-01

    A high power (2 kW, CW) magnetron-based microwave system operating at 2.45 GHz has been designed, tested, characterized, and used to produce plasma. The system consists of a microwave source, an isolator, a directional coupler, a threestub tuner, a high voltage break, a microwave vacuum window, and a microwave launcher. These microwave components were simulated using microwave studio software. The low power and full term characterization of the microwave system has been done using vector network analyzer. The system was tested for 2 kW continuous wave of microwave power using glass-water load. The microwave system has been developed to study the microwave interaction with plasma at different operation regimes (Gases: Nitrogen, argon and hydrogen; Gas pressure : $10^{−5}–10^{−3}$ mbar; Microwave power : 300–1000W; Magnetic field: 875–1000 G) and to extract the proton beam current with hydrogen produced plasma. A plasma density $\\sim 5 \\times 10^{11}$ cm−3 and average electron temperature of ∼13 eV was obtained. This article describes various aspects of the microwave system including design, fabrication, characterization and performance studies of the microwave components.

  14. Numerical simulations of gas mixing effect in Electron Cyclotron Resonance Ion Sources

    CERN Document Server

    Mironov, V; Bondarchenko, A; Efremov, A; Loginov, V

    2016-01-01

    The particle-in-cell MCC code NAM-ECRIS is used to simulate the ECRIS plasma sustained in a mixture of Kr with O2, N2, Ar, Ne and He. The model assumes that ions are electrostatically confined in ECR zone by a dip in the plasma potential. Gain in the extracted krypton ion currents is seen for the highest charge states; the gain is maximized when oxygen is used as the mixing gas. A special feature of oxygen is that most of singly charged oxygen ions are produced after dissociative ionization of oxygen molecules with the large kinetic energy release of around 5 eV per ion. Increased loss rate of energetic lowly charged ions of the mixing element requires building up of the retarding potential barrier close to ECR surface to equilibrate electron and ion losses out of the plasma. In the mixed plasmas, the barrier value is large (~1 V) compared to the pure Kr plasma (~0.01 V), with the longer confinement times of krypton ions and with the much higher ion temperatures.

  15. Progress of superconducting electron cyclotron resonance ion sources at Institute of Modern Physics (IMP)

    Science.gov (United States)

    Sun, L.; Lu, W.; Feng, Y. C.; Zhang, W. H.; Zhang, X. Z.; Cao, Y.; Zhao, Y. Y.; Wu, W.; Yang, T. J.; Zhao, B.; Zhao, H. W.; Ma, L. Z.; Xia, J. W.; Xie, D.

    2014-02-01

    Superconducting ECR ion sources can produce intense highly charged ion beams for the application in heavy ion accelerators. Superconducting Electron Resonance ion source with Advanced Design (SECRAL) is one of the few fully superconducting ECR ion sources that has been successfully built and put into routine operation for years. With enormous efforts and R&D work, promising results have been achieved with the ion source. Heated by the microwave power from a 7 kW/24 GHz gyrotron microwave generator, very intense highly charged gaseous ion beams have been produced, such as 455 eμA Xe27+, 236 eμA Xe30+, and 64 eμA Xe35+. Since heavy metallic ion beams are being more and more attractive and important for many accelerator projects globally, intensive studies have been made to produce highly charged heavy metal ion beams, such as those from bismuth and uranium. Recently, 420 eμA Bi30+ and 202 eμA U33+ have been produced with SECRAL source. This paper will present the latest results with SECRAL, and the operation status will be discussed as well. An introduction of recently started SECRAL II project will also be given in the presentation.

  16. Fast camera studies at an electron cyclotron resonance table plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Rácz, R., E-mail: rracz@atomki.hu [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen, Bem tér 18/c (Hungary); Department of Experimental Physics, University of Debrecen, H-4032 Debrecen, Egyetem tér 1 (Hungary); Biri, S. [Institute for Nuclear Research (ATOMKI), H-4026 Debrecen, Bem tér 18/c (Hungary); Hajdu, P.; Pálinkás, J. [Department of Experimental Physics, University of Debrecen, H-4032 Debrecen, Egyetem tér 1 (Hungary)

    2014-02-15

    A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the “big” ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

  17. Progress of superconducting electron cyclotron resonance ion sources at Institute of Modern Physics (IMP).

    Science.gov (United States)

    Sun, L; Lu, W; Feng, Y C; Zhang, W H; Zhang, X Z; Cao, Y; Zhao, Y Y; Wu, W; Yang, T J; Zhao, B; Zhao, H W; Ma, L Z; Xia, J W; Xie, D

    2014-02-01

    Superconducting ECR ion sources can produce intense highly charged ion beams for the application in heavy ion accelerators. Superconducting Electron Resonance ion source with Advanced Design (SECRAL) is one of the few fully superconducting ECR ion sources that has been successfully built and put into routine operation for years. With enormous efforts and R&D work, promising results have been achieved with the ion source. Heated by the microwave power from a 7 kW/24 GHz gyrotron microwave generator, very intense highly charged gaseous ion beams have been produced, such as 455 eμA Xe(27+), 236 eμA Xe(30+), and 64 eμA Xe(35+). Since heavy metallic ion beams are being more and more attractive and important for many accelerator projects globally, intensive studies have been made to produce highly charged heavy metal ion beams, such as those from bismuth and uranium. Recently, 420 eμA Bi(30+) and 202 eμA U(33+) have been produced with SECRAL source. This paper will present the latest results with SECRAL, and the operation status will be discussed as well. An introduction of recently started SECRAL II project will also be given in the presentation.

  18. 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.

    Science.gov (United States)

    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.

  19. 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

    Science.gov (United States)

    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.

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    Yorita, T., E-mail: yorita@rcnp.osaka-u.ac.jp; Hatanaka, K.; Fukuda, M.; Ueda, H.; Yasuda, Y.; Morinobu, S.; Tamii, A.; Kamakura, K. [Research Center for Nuclear Physics (RCNP), Osaka University, Osaka 567-0047 (Japan)

    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.

  1. Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. I. Compression-driven Instabilities and the Electron Heating Mechanism

    Science.gov (United States)

    Sironi, Lorenzo; Narayan, Ramesh

    2015-02-01

    In systems accreting well below the Eddington rate, such as the central black hole in the Milky Way (Sgr A*), the plasma in the innermost regions of the disk is believed to be collisionless and have two temperatures, with the ions substantially hotter than the electrons. However, whether a collisionless faster-than-Coulomb energy transfer mechanism exists in two-temperature accretion flows is still an open question. We study the physics of electron heating during the growth of ion velocity-space instabilities by means of multidimensional, fully kinetic, particle-in-cell (PIC) simulations. A background large-scale compression—embedded in a novel form of the PIC equations—continuously amplifies the field. This constantly drives a pressure anisotropy P > P ∥ because of the adiabatic invariance of the particle magnetic moments. We find that, for ion plasma beta values β0i ~ 5-30 appropriate for the midplane of low-luminosity accretion flows (here, β0i is the ratio of ion thermal pressure to magnetic pressure), mirror modes dominate if the electron-to-proton temperature ratio is T 0e /T 0i >~ 0.2, whereas for T 0e /T 0i ~ 2 me /mi —governed by the conservation of the particle magnetic moment in the growing fields of the instability—is proportional to the initial electron temperature, and it scales with the magnetic energy of ion cyclotron waves. Our results have implications for two-temperature accretion flows as well as for solar wind and intracluster plasmas.

  2. Characteristics of electron cyclotron resonance plasma formed by lower hybrid current drive grill antenna

    Indian Academy of Sciences (India)

    P K Sharma; S L Rao; K Mishra; R G Trivedi; D Bora

    2008-03-01

    A 3.7 GHz system, which is meant for LHCD experiments on ADITYA tokamak, is used for producing ECR discharge. The ECR discharge is produced by setting the appropriate resonance magnetic field of 0.13 T, with hydrogen at a fill pressure of about 5 × 10-5 Torr. The RF powe r, up to 10 kW (of which ∼ 50% is reflected back), with a typical pulse length of 50 ms, is injected into the vacuum chamber of the ADITYA tokamak by a LHCD grill antenna and is used for plasma formation. The average coupled RF power density (the RF power/a typical volume of the plasma) is estimated to be ∼ 5 kW/m3. When the ECR appears inside the tokamak chamber for the given pumping frequency ( = 3.7 GHz) a plasma with a density () ∼ 4 × 1016 m-3 and electron temperature ∼ 8 eV is produced. The density and temperature during the RF pulse are measured by sets of Langmuir probes, located toroidally, on either side of the antenna. signals are also monitored to detect ionization. An estimate of density and temperature based on simple theoretical calculation agrees well with our experimental measurements. The plasma produced by the above mechanism is further used to characterize the ECR-assisted low voltage Ohmic start-up discharges. During this part of the experiments, Ohmic plasma is formed using capacitor banks. The plasma loop voltage is gradually decreased, till the discharge ceases to form. The same is repeated in the presence of ECR-formed plasma (RF pre-ionization), formed 10 ms prior to the loop voltage. We have observed that (with LHCD-induced) ECR-assisted Ohmic start-up discharges is reliably and repeatedly obtained with reduced loop voltage requirement and breakdown time decreases substantially. The current ramp-up rates also decrease with reduced loop voltage operation. These studies established that ECR plasma formed with LHCD system exhibits similar characteristics as reported earlier by dedicated ECR systems. This experiment also addresses the issue of whether ECR plasma

  3. Does metformin increase paraoxonase activity in patients with the metabolic syndrome? Additional data from the MEFISTO study.

    Science.gov (United States)

    Meaney, Eduardo; Sierra-Vargas, Patricia; Meaney, Alejandra; Guzmán-Grenfell, Martín; Ramírez-Sánchez, Israel; Hicks, Juan Jose; Olivares-Corichi, Ivonne; Ceballos, Guillermo

    2012-06-01

    In a subanalysis on the metformin, arterial function, intima-media thickness, and nitroxidation in the metabolic syndrome (MEFISTO)(8) (an open-label fashion, with 1 year of 850 mg daily of metformin) subjects' samples, we measured the paraoxonase 1 (PON1) activity in 39 patients that finished the study and relate values with high density lipoprotein (HDL). The comparative PON1 activities at the beginning and at the end of the study were 5.528 ± 0.588 and 4.743 ± 0.619 nmol/mg protein/min (NS) for control group and 3.229 ± 0.403 and 5.135 ± 0.585 nmol/mg protein/min (p < 0.02) for the metformin group. Our data showed an enhance of PON1 activity in patients with metabolic syndrome treated with metformin, although in them, the raise of HDL concentration was less than control patients, suggesting that the increase in quality (measured here as PON1 activity) could be at least as important as an increase in its concentration. Our results point out that there is a relationship among PON1 activity and the reduction of carotideal intima-media thickness.

  4. The Submillimeter Wave Electron Cyclotron Emission Diagnostic for the Alcator C-Mod Tokamak.

    Science.gov (United States)

    Hsu, Thomas C.

    This thesis describes the engineering design, construction, and operation of a high spatial resolution submillimeter wave diagnostic for electron temperature measurements on Alcator C-Mod. Alcator C-Mod is a high performance compact tokamak capable of producing diverted, shaped plasmas with a major radius of 0.67 meters, minor radius of 0.21 centimeters, plasma current of 3 MA. The maximum toroidal field is 9 Tesla on the magnetic axis. The ECE diagnostic includes three primary components: a 10.8 meter quasioptical transmission line, a rapid scanning Michelson interferometer, and a vacuum compatible calibration source. Due to the compact size and high field of the tokamak the ECE system was designed to have a spectral range from 100 to 1000 GHz with frequency resolution of 5 GHz and spatial resolution of one centimeter. The beamline uses all reflecting optical elements including two off-axis parabolic mirrors with diameters of 20 cm. and focal lengths of 2.7 meters. Techniques are presented for grinding and finishing the mirrors to sufficient surface quality to permit optical alignment of the system. Measurements of the surface figure confirm the design goal of 1/4 wavelength accuracy at 1000 GHz. Extensive broadband tests of the spatial resolution of the ECE system are compared to a fundamental mode Gaussian beam model, a three dimensional vector diffraction model, and a geometric optics model. The Michelson interferometer is a rapid scanning polarization instrument which has an apodized frequency resolution of 5 GHz and a minimum scan period of 7.5 milliseconds. The novel features of this instrument include the use of precision linear bearings to stabilize the moving mirror and active counterbalancing to reduce vibration. Beam collimation within the instrument is done with off-axis parabolic mirrors. The Michelson also includes a 2-50 mm variable aperture and two signal attenuators constructed from crossed wire grid polarizers. To make full use of the advantages

  5. Temperature and density evolution during decay in a 2.45 GHz hydrogen electron cyclotron resonance plasma: Off-resonant and resonant cases

    Energy Technology Data Exchange (ETDEWEB)

    Cortázar, O. D. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A.; Vizcaíno-de-Julián, A. [ESS Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)

    2013-09-15

    Time resolved electron temperature and density measurements during the decay stage in a hydrogen electron cyclotron resonance (ECR) plasma are presented for a resonance and off-resonance magnetic field configurations. The measurements are conducted on a ECR plasma generator excited at 2.45 GHz denominated test-bench for ion-sources plasma studies at ESS Bilbao. The plasma parameters evolution is studied by Langmuir probe diagnostic with synchronized sample technique developed for repetitive pulsed plasmas with a temporal resolution of 200 ns in typical decay processes of about 40 μs. An afterglow transient is clearly observed in the reflected microwave power signal from the plasma. Simultaneously, the electron temperature evolution shows rebounding peaks that may be related to the interplay between density drop and microwave coupling with deep impact on the Electron Energy Distribution Function. The correlation of such structures with the plasma absorbed power and the coupling quality is also reported.

  6. Note: Easy-to-maintain electron cyclotron resonance (ECR) plasma sputtering apparatus featuring hybrid waveguide and coaxial cables for microwave delivery.

    Science.gov (United States)

    Akazawa, Housei

    2016-06-01

    The branched-waveguide electron cyclotron resonance plasma sputtering apparatus places quartz windows for transmitting microwaves into the plasma source not in the line of sight of the target. However, the quartz windows must be replaced after some time of operation. For maintenance, the loop waveguide branching from the T-junction must be dismounted and re-assembled accurately, which is a time-consuming job. We investigated substituting the waveguide branches with two sets of coaxial cables and waveguide/coaxial cable converters to simplify assembly as far as connection and disconnection go. The resulting hybrid system worked well for the purposes of plasma generation and film deposition.

  7. Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets.

    Science.gov (United States)

    Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki

    2012-02-01

    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. A fresh look at electron cyclotron current drive power requirements for stabilization of tearing modes in ITER

    Energy Technology Data Exchange (ETDEWEB)

    La Haye, R. J., E-mail: lahaye@fusion.gat.com [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2015-12-10

    ITER is an international project to design and build an experimental fusion reactor based on the “tokamak” concept. ITER relies upon localized electron cyclotron current drive (ECCD) at the rational safety factor q=2 to suppress or stabilize the expected poloidal mode m=2, toroidal mode n=1 neoclassical tearing mode (NTM) islands. Such islands if unmitigated degrade energy confinement, lock to the resistive wall (stop rotating), cause loss of “H-mode” and induce disruption. The International Tokamak Physics Activity (ITPA) on MHD, Disruptions and Magnetic Control joint experiment group MDC-8 on Current Drive Prevention/Stabilization of Neoclassical Tearing Modes started in 2005, after which assessments were made for the requirements for ECCD needed in ITER, particularly that of rf power and alignment on q=2 [1]. Narrow well-aligned rf current parallel to and of order of one percent of the total plasma current is needed to replace the “missing” current in the island O-points and heal or preempt (avoid destabilization by applying ECCD on q=2 in absence of the mode) the island [2-4]. This paper updates the advances in ECCD stabilization on NTMs learned in DIII-D experiments and modeling during the last 5 to 10 years as applies to stabilization by localized ECCD of tearing modes in ITER. This includes the ECCD (inside the q=1 radius) stabilization of the NTM “seeding” instability known as sawteeth (m/n=1/1) [5]. Recent measurements in DIII-D show that the ITER-similar current profile is classically unstable, curvature stabilization must not be neglected, and the small island width stabilization effect from helical ion polarization currents is stronger than was previously thought [6]. The consequences of updated assumptions in ITER modeling of the minimum well-aligned ECCD power needed are all-in-all favorable (and well-within the ITER 24 gyrotron capability) when all effects are included. However, a “wild card” may be broadening of the localized

  9. A fresh look at electron cyclotron current drive power requirements for stabilization of tearing modes in ITER

    Science.gov (United States)

    La Haye, R. J.

    2015-12-01

    ITER is an international project to design and build an experimental fusion reactor based on the "tokamak" concept. ITER relies upon localized electron cyclotron current drive (ECCD) at the rational safety factor q=2 to suppress or stabilize the expected poloidal mode m=2, toroidal mode n=1 neoclassical tearing mode (NTM) islands. Such islands if unmitigated degrade energy confinement, lock to the resistive wall (stop rotating), cause loss of "H-mode" and induce disruption. The International Tokamak Physics Activity (ITPA) on MHD, Disruptions and Magnetic Control joint experiment group MDC-8 on Current Drive Prevention/Stabilization of Neoclassical Tearing Modes started in 2005, after which assessments were made for the requirements for ECCD needed in ITER, particularly that of rf power and alignment on q=2 [1]. Narrow well-aligned rf current parallel to and of order of one percent of the total plasma current is needed to replace the "missing" current in the island O-points and heal or preempt (avoid destabilization by applying ECCD on q=2 in absence of the mode) the island [2-4]. This paper updates the advances in ECCD stabilization on NTMs learned in DIII-D experiments and modeling during the last 5 to 10 years as applies to stabilization by localized ECCD of tearing modes in ITER. This includes the ECCD (inside the q=1 radius) stabilization of the NTM "seeding" instability known as sawteeth (m/n=1/1) [5]. Recent measurements in DIII-D show that the ITER-similar current profile is classically unstable, curvature stabilization must not be neglected, and the small island width stabilization effect from helical ion polarization currents is stronger than was previously thought [6]. The consequences of updated assumptions in ITER modeling of the minimum well-aligned ECCD power needed are all-in-all favorable (and well-within the ITER 24 gyrotron capability) when all effects are included. However, a "wild card" may be broadening of the localized ECCD by the presence of

  10. Broadband measurements of electron cyclotron emission in TFTR (Tokamak Fusion Test Reactor) using a quasi-optical light collection system and a polarizing Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; Diesso, M.; McCarthy, M.P.; Montague, J.; Rocco, R.

    1988-04-01

    For the past three years, a Fourier transform spectrometer diagnostic system, employing a fast-scanning polarizing Michelson interferometer, has been operating on the TFTR tokamak at Princeton Plasma Physics Laboratory. It is used to measure the electron cyclotron emission spectrum over the range 2.5 to 18 cm/sup /minus/1/ (75-540 GHz) with a resolution of 0.123 cm/sup /minus/1/(3.7 GHz), at a rate of 72 spectra per second. The quasi-optical system for collecting the light and transporting it through the interferometer to the detector has been designed using the concepts of both Gaussian and geometrical optics in order to produce a system that is efficient over the entire spectral range. The commerical Michelson interferometer was custom-made for this project and is at the state of the art for this type of specialized instrument. Various pre-installation and post-installation tests of the optical system and the interferometer were performed and are reported here. An error propagation analysis of the absolute calibration process is given. Examples of electron cyclotron emission spectra measured in two polarization directions are given, and electron temperature profiles derived from each of them are compared. 34 refs., 17 figs.

  11. High current H{sub 2}{sup +} and H{sub 3}{sup +} beam generation by pulsed 2.45 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan; Peng, Shixiang, E-mail: sxpeng@pku.edu.cn; Ren, Haitao; Zhao, Jie; Chen, Jia; Zhang, Tao; Guo, Zhiyu [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); Zhang, Ailin [University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jia' er [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, Peking University, Beijing 100871 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2014-02-15

    The permanent magnet 2.45 GHz electron cyclotron resonance ion source at Peking University can produce more than 100 mA hydrogen ion beam working at pulsed mode. For the increasing requirements of cluster ions (H{sub 2}{sup +} and H{sub 3}{sup +}) in linac and cyclotron, experimental study was carried out to further understand the hydrogen plasma processes in the ion source for the generation of cluster ions. The constituents of extracted beam have been analyzed varying with the pulsed duration from 0.3 ms to 2.0 ms (repetition frequency 100 Hz) at different operation pressure. The fraction of cluster ions dramatically increased when the pulsed duration was lower than 0.6 ms, and more than 20 mA pure H{sub 3}{sup +} ions with fraction 43.2% and 40 mA H{sub 2}{sup +} ions with fraction 47.7% were obtained when the operation parameters were adequate. The dependence of extracted ion fraction on microwave power was also measured at different pressure as the energy absorbed by plasma will greatly influence electron temperature and electron density then the plasma processes in the ion source. More details will be presented in this paper.

  12. Efficiency of the generation of impulsion by cyclotron waves currents of the electrons in an Axisymmetric Tokamak; Eficiencia de la generacion de corrientes de impulsion por ondas ciclotronicas de los electrones en un Tokamak axisimetrico

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez T, C.; Beltran P, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-07-01

    The neoclassical theory of transport is used to calculate the current efficiency of electronic cyclotron impulsion (ECCD) in an axisymmetric tokamak in the few collisions regime. The standard parameter of the tokamak is used to obtain a system of equations that describe the hydrodynamic of the plasma, where the ponderomotive force (PM) due to high power radio frequency waves is taken in account. The PM force is produced in the proximity of electron cyclotron resonance surface in a specific poloidal localization. The efficiency ECCD is analyzed in the cases of first and second harmonic (for different angles of injection of radio frequency waves) and it is validated using the experimental values of the TCV and T-10 tokamaks. The results are according to those obtained by means of the techniques of the Green functions. (Author)

  13. Study of electronic heat transport in plasma through diagnosis based on modulated electron cyclotron heating; Etudes de transport de la chaleur electronique par injection modulee d'ondes a la frequence cyclotronique electronique

    Energy Technology Data Exchange (ETDEWEB)

    Clemencon, A.; Guivarch, C

    2003-07-01

    In order to make nuclear fusion energetically profitable, it is crucial to heat and confine the plasma efficiently. Studying the behavior of the heat diffusion coefficient is a key issue in this matter. The use of modulated electron cyclotron heating as a diagnostic has suggested the existence of a transport barrier under certain plasma conditions. We have determined the solution to the heat transport equation, for several heat diffusion coefficient profiles. By comparing the analytical solutions with experimental data; we are able to study the heat diffusion coefficient profile. Thus, in certain experiments, we can confirm that the heat diffusion coefficient switches from low to high values at the radius where the electron cyclotron heat deposition is made. (authors)

  14. An Impurity Emission Survey in the near UV and Visible Spectral Ranges of Electron Cyclotron Heated (ECH) Plasma in the TJ-II Stellarator

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, K. J.; Zurro, B.; Baciero, A.

    2001-07-01

    We report on a near-ultraviolet and visible spectroscopic survey (220-600 nm) of electron cyclotron resonance (ECR) heated plasmas created in the TJ-II stellarator, with central electron temperatures up to 2 keV and central electron densities up to 1.7 x 10 ''19 m''-3. Approximately 1200 lines from thirteen elements have been identified. The purpose of the work is to identify the principal impurities and spectral lines present in TJ-II plasmas, as well as their possible origin to search for transitions from highly ionised ions. This work will act as a base for identifying suitable transitions for following the evolution of impurities under different operating regimens and multiplet systems for line polarisation studies. It is intended to use the database creates as a spectral line reference for comparing spectra under different operating and plasma heating regimes. (Author)

  15. 2D Particle-In-Cell simulations of the electron-cyclotron instability and associated anomalous transport in Hall-Effect Thrusters

    Science.gov (United States)

    Croes, Vivien; Lafleur, Trevor; Bonaventura, Zdenek; Péchereau, François; Bourdon, Anne; Chabert, Pascal

    2016-09-01

    This work studies the electron-cyclotron instability in Hall-Effect Thrusters (HETs) using a 2D Particle-In-Cell (PIC) simulation. The simulation is configured with a Cartesian coordinate system where a magnetic field, B0, is aligned along the X-axis (radial direction, including absorbing walls), a constant electric field, E0, along the Z-axis (axial direction, perpendicular to simulation plane), and the E0xB0 direction along the Y-axis (O direction, with periodic boundaries). Although for low plasma densities classical electron-neutral collisions theory describes well electron transport, at sufficiently high densities (as measured in HETs) a strong instability can be observed that enhances the electron mobility, even in the absence of collisions. The instability generates high frequency ( MHz) and short wavelength ( mm) fluctuations in both the electric field and charged particle densities. We investigate the correlation between these fluctuations and their role with anomalous electron transport; complementing previous 1D simulations. Plasma is self-consistently heated by the instability, but since the latter does not reach saturation in an infinitely long 2D system, saturation is achieved through implementation of a finite axial length that models convection in E0 direction. With support of Safran Aircraft Engines.

  16. Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sources.

    Science.gov (United States)

    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.

  17. Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sourcesa)

    Science.gov (United States)

    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.

  18. Preparation of high-quality hydrogenated amorphous silicon film with a new microwave electron cyclotron resonance chemical vapour deposition system assisted with hot wire

    Institute of Scientific and Technical Information of China (English)

    Zhu Xiu-Hong; Chen Guang-Hua; Yin Sheng-Yi; Rong Yan-Dong; Zhang Wen-Li; Hu Yue-Hui

    2005-01-01

    The preparation of high-quality hydrogenated amorphous silicon (a-Si:H) film with a new microwave electron cyclotron resonance-chemical vapour deposition (MWECR-CVD) system assisted with hot wire is presented. In this system the hot wire plays an important role in perfecting the microstructure as well as improving the stability and the optoelectronic properties of the a-Si:H film. The experimental results indicate that in the microstructure of the a-Si:H film, the concentration of dihydride is decreased and a trace of microcrystalline occurs, which is useful to improve its stability, and that in the optoelectronic properties of the a-Si:H film, the deposition rate reaches above 2.0nm/s and the photosensitivity increases up to 4.71× 105.

  19. Effects of initial layers on surface roughness and crystallinity of microcrystalline silicon thin films formed by remote electron cyclotron resonance silane plasma

    CERN Document Server

    Murata, K; Hori, Masaki; Goto, T; Ito, M

    2002-01-01

    We have observed mu c-Si:H films grown in the glass substrate in electron cyclotron resonance plasma-enhanced chemical vapor deposition employing two-step growth (TSG) method, where the seed layer was formed without charged species firstly, and subsequently, the film with charged species. The mu c-Si:H films with smooth surface and high crystallinity were synthesized with a relatively high deposition rate at a low substrate temperature by TSG. By Fourier transform infrared attenuated-total reflection, it was found that the surface roughness and crystallinity of seed layer were related to the ratio of SiH bonds over SiH sub 2 ones in the film. Consequently, the control of chemical bonds at the initial layer is of importance and TSG method is effective for the formation of mu c-Si:H film with high quality.

  20. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ken-ichi, E-mail: yoshida.kennichi71@jaea.go.jp; Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-02-15

    A flat distribution of the minimum magnetic field (flat-B{sub min}) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical B{sub min}. To form a flat-B{sub min} structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-B{sub min} structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  1. Effect of electron cyclotron resonance ion source frequency tuning on ion beam intensity and quality at Department of Physics, University of Jyvaeskylae

    Energy Technology Data Exchange (ETDEWEB)

    Toivanen, V.; Koivisto, H.; Steczkiewicz, O.; Tarvainen, O.; Ropponen, T. [Department of Physics, University of Jyvaeskylae (JYFL) (Finland); Celona, L.; Gammino, S.; Mascali, D.; Ciavola, G. [Instituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, 95123 Catania (Italy)

    2010-02-15

    Ion beam intensity and quality have a crucial effect on the operation efficiency of the accelerator facilities. This paper presents the investigations on the ion beam intensity and quality after the mass separation performed with the Department of Physics, University of Jyvaeskylae 14 GHz electron cyclotron resonance ion source by sweeping the microwave in the 14.05-14.13 GHz range. In many cases a clear variation in the ion beam intensity and quality as a function of the frequency was observed. The effect of frequency tuning increased with the charge state. In addition, clear changes in the beam structure seen with the beam viewer were observed. The results confirmed that frequency tuning can have a remarkable effect on ion beam intensity and quality especially in the case of highly charged ion beams. The examples presented here represent the typical charge state behavior observed during the measurements.

  2. First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

    Energy Technology Data Exchange (ETDEWEB)

    Thomae, R.; Conradie, J.; Delsink, H.; Du Plessis, H.; Fourie, D.; Klopp, M.; Kohler, I.; Lussi, C.; McAlister, R.; Ntshangase, S.; Sakildien, M. [iThemba LABS, P.O Box 722, Somerset West 7130 (South Africa); Hitz, D. [CEA/DRFMC, 17 Av. Des Martyrs, 38054, Grenoble Cedex 9 (France); Kuechler, D. [CERN, BE/ABP/HSL, 1211 Geneva 23 (Switzerland)

    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.

  3. First commissioning results with the Grenoble test electron cyclotron resonance ion source at iThemba LABS.

    Science.gov (United States)

    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.

  4. The effect of magnetic field strength on the time evolution of high energy bremsstrahlung radiation created by an electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ropponen, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)], E-mail: tommi.ropponen@phys.jyu.fi; Tarvainen, O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Jones, P.; Peura, P.; Kalvas, T. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland); Suominen, P. [Prizztech Ltd/Magnet Technology Centre, Tiedepuisto 4, FI-28600 Pori (Finland); Koivisto, H.; Arje, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, FI-40014 (Finland)

    2009-03-11

    An electron cyclotron resonance (ECR) ion source is one of the most used ion source types for high charge state heavy ion production. In ECR plasma the electrons are heated by radio frequency microwaves in order to provide ionization of neutral gases. As a consequence, ECR heating also generates very high electron energies (up to MeV region) which can produce a vast amount of bremsstrahlung radiation causing problems with radiation shielding and heating superconducting cryostat of an ECR ion source. To gain information about the time evolution of the electron energies in ECR plasma radial bremsstrahlung measurements were performed. JYFL 14 GHz ECR ion source was operated in pulsed mode and time evolution measurements were done with different axial magnetic field strengths with oxygen and argon plasmas. Bremsstrahlung data were analyzed with a time interval of 2 ms yielding information at unprecedented detail about the time evolution of high energy bremsstrahlung radiation from an ECR ion source. It was observed, for example, that reaching the steady state phase of the plasma bremsstrahlung requires several hundred milliseconds and the steady state time can be different with different gases.

  5. Modification of anisotropic plasma diffusion via auxiliary electrons emitted by a carbon nanotubes-based electron gun in an electron cyclotron resonance ion source.

    Science.gov (United States)

    Malferrari, L; Odorici, F; Veronese, G P; Rizzoli, R; Mascali, D; Celona, L; Gammino, S; Castro, G; Miracoli, R; Serafino, T

    2012-02-01

    The diffusion mechanism in magnetized plasmas is a largely debated issue. A short circuit model was proposed by Simon, assuming fluxes of lost particles along the axial (electrons) and radial (ions) directions which can be compensated, to preserve the quasi-neutrality, by currents flowing throughout the conducting plasma chamber walls. We hereby propose a new method to modify Simon's currents via electrons injected by a carbon nanotubes-based electron gun. We found this improves the source performances, increasing the output current for several charge states. The method is especially sensitive to the pumping frequency. Output currents for given charge states, at different auxiliary electron currents, will be reported in the paper and the influence of the frequency tuning on the compensation mechanism will be discussed.

  6. Non-inductive current built-up by local electron cyclotron heating and current drive with a 28 GHz focused beam on QUEST

    Science.gov (United States)

    Onchi, Takumi; Idei, Hiroshi; Hasegawa, Makoto; Ohwada, Hiroaki; Zushi, Hideki; Hanada, Kazuaki; Kariya, Tsuyoshi; Mishra, Kishore; Shikama, Taichi; Quest Team

    2016-10-01

    The plasma current can be driven solely by injecting electron cyclotron waves (ECWs) in spherical tokamak (ST) configuration. A system of 28 GHz gyrotron (maximum power: 270 kW) is renewed and reinstalled on QUEST. A focused ECW beam, whose diameter is about 5 cm at the second harmonic resonance, is injected for local ECW heating and current drive. The local power density at resonance exceeds 75 MW/m2 at an injection power of 150 kW. The incident ECW polarization can be adjusted employing the phase shifter consisting of two corrugated plates. During 1.25 second pulse of ECH, plasma current is built up to Ip = 70 kA fully non-inductively with a core electron density of ne > 1018 m-3. The closed flux in such ST plasma is determined at the inboard limiter on the center stack. Energetic electrons are also responsible for the pressure and equilibrium. This work is supported by JSPS KAKENHI (15H04231, 15K17800), NIFS Collaboration Research program (NIFS13KUTR085, NIFS11KUTR069, NIFS16KUTR114).

  7. Restoration of the plasma discharge during density limit disruptions in the T-10 tokamak using electron cyclotron heating and ohmic power supply system

    Science.gov (United States)

    Savrukhin, P. V.; Shestakov, E. A.

    2016-11-01

    Experiments in the T-10 tokamak [Alikaev et al., Plasma Phys. Controlled Fusion 30, 381 (1988)] have demonstrated the possibility of control of the plasma current and prevention of formation of the non-thermal (Eγ > 150 keV) electron beams after an energy quench at the density limit disruption using electron cyclotron heating (ECRH) and controlled operation of the Ohmic power supply system. Quasi-stable plasma operation with repetitive sawtooth oscillations can be restored after an energy quench using high auxiliary power Pec > 2-5 Poh. Optimal conditions of the plasma discharge recovery after an energy quench using auxiliary heating are identified. At high auxiliary power, restoration of the plasma discharge can be provided with the location of the EC resonance zone within the whole plasma cross section. The auxiliary power required for discharge restoration is minimal when the power is deposited around the m = 2, n = 1 magnetic island (here m and n poloidal and toroidal wave numbers). The threshold ECRH power increases linearly with plasma current. Prevention of the non-thermal electron beams during density limit disruption is associated with stabilization of bursts of the magnetohydrodynamic modes, creation of the saturated magnetic islands, and heating of the background plasma using ECRH. Plasma discharge recovery after an energy quench in a tokamak reactor using auxiliary heating and controllable reduction of the plasma current is discussed.

  8. Cyclotron resonance absorption in ionospheric plasma

    Science.gov (United States)

    Villalon, Elena

    1991-04-01

    The mode conversion of ordinary polarized electromagnetic waves into electrostatic cyclotron waves in the inhomogeneous ionospheric plasma is investigated. Near resonance the warm plasma dispersion relation is a function of the angle theta between the geomagnetic field and the density gradient and of the wave frequency omega, which lies between the electron cyclotron frequency and its doubling. The differential equations describing the electric field amplitudes near the plasma resonance are studied, including damping at the second gyroharmonic. The energy transmission coefficients and power absorbed by the cyclotron waves are calculated. The vertical penetration of the plasma wave amplitudes is estimated using a WKB analysis of the wave equation.

  9. Influence of microwave driver coupling design on plasma density at Testbench for Ion sources Plasma Studies, a 2.45 GHz Electron Cyclotron Resonance Plasma Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Megía-Macías, A.; Vizcaíno-de-Julián, A. [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Cortázar, O. D., E-mail: dcortazar@essbilbao.org [E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain); Universidad de Castilla-La Mancha, ETSII, C.J. Cela s/n, 13170 Ciudad Real (Spain)

    2014-03-15

    A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor.

  10. Dynamics of multiple flux tubes in sawtoothing KSTAR plasmas heated by electron cyclotron waves: I. Experimental analysis of the tube structure

    Science.gov (United States)

    Choe, G. H.; Yun, G. S.; Nam, Y.; Lee, W.; Park, H. K.; Bierwage, A.; Domier, C. W.; Luhmann, N. C., Jr.; Jeong, J. H.; Bae, Y. S.; the KSTAR Team

    2015-01-01

    Multiple (two or more) flux tubes are commonly observed inside and/or near the q = 1 flux surface in KSTAR tokamak plasmas with localized electron cyclotron resonance heating and current drive (ECH/CD). Detailed 2D and quasi-3D images of the flux tubes obtained by an advanced imaging diagnostic system showed that the flux tubes are m/n = 1/1 field-aligned structures co-rotating around the magnetic axis. The flux tubes typically merge together and become like the internal kink mode of the usual sawtooth, which then collapses like a usual sawtooth crash. A systematic scan of ECH/CD beam position showed a strong correlation with the number of flux tubes. In the presence of multiple flux tubes close to the q = 1 surface, the radially outward heat transport was enhanced, which explains naturally temporal changes of electron temperature. We emphasize that the multiple flux tubes are a universal feature distinct from the internal kink instability and play a critical role in the control of sawteeth using ECH/CD.

  11. Electron Cyclotron Resonance-Sputtered Nanocarbon Film Electrode Compared with Diamond-Like Carbon and Glassy Carbon Electrodes as Regards Electrochemical Properties and Biomolecule Adsorption

    Science.gov (United States)

    Xue, Qiang; Kato, Dai; Kamata, Tomoyuki; Umemura, Shigeru; Hirono, Shigeru; Niwa, Osamu

    2012-09-01

    The electrochemical properties and biocompatible characteristics at an electron cyclotron resonance (ECR)-sputtered nanocarbon film electrode, a diamond-like carbon (DLC) electrode and a glassy carbon (GC) electrode have been studied. The three carbon electrodes show significant current reductions with increased peak separations as a result of protein fouling before oxygen plasma treatment, but the current reductions of the ECR-sputtered nanocarbon and DLC film electrodes are smaller than that of the GC electrode due to their superior surface flatness. The oxygen plasma pretreated ECR-sputtered nanocarbon film electrode exhibits a significant improvement in anti-fouling performance with an improved electron transfer. This is because the pretreated ECR-sputtered nanocarbon film enabled the surface to introduce surface oxygen functionalities that not only improve the interaction between the analytes and the electrode surface but also make the film surface more hydrophilic, which is important for the suppression of biomolecule adsorption. At the same time, the pretreated ECR-sputtered nanocarbon film also retained an ultraflat surface even after pretreatment as a result of the low background current. This excellent performance can only be achieved with our ECR-sputtered nanocarbon film, indicating that our film is promising for application to electrochemical detectors for various biomolecular analytes.

  12. Modified Multipole Structure for Electron Cyclotron Resonance Ion Sources%对ECR离子源多极磁场结构的改进

    Institute of Scientific and Technical Information of China (English)

    P.Suominen; T.Ropponen; H.Koivisto

    2007-01-01

    Experiments have shown that especially the radial magnetic field component plays a crucial role in the production of highly charged ions with Electron Cyclotron Resonance Ion Sources(ECRIS).However,in several room temperature operating ECRISs the radial magnetic field strength is below the optimum value,mainly due to the limits in permanent magnet technology.Remarkable radial magnetic field improvement can be reached with a relatively simple and cost-effective idea called Modified MultiPole Structure (MMPS).The MMPS differs strongly from the former structures because here the magnetic field is increased only locally without affecting the plasma size.The idea was studied experimentally with a new MMPS plasma chamber prototype.which was designed and constructed for the JYFL 6.4GHz ECRIS.The new chamber is versatile and made it possible to perform several new types of measurements.These showed that the MMPS is especially applicable to increase very high charge-state ion production.Typically the ion current increases more than a factor of 2 in the case of highly charged ions such as Ar16+.

  13. Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions.

    Science.gov (United States)

    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.

  14. Metamaterial lens of specifiable frequency-dependent focus and adjustable aperture for electron cyclotron emission in the DIII-D tokamak

    CERN Document Server

    Hammond, K C; Massidda, S D; Volpe, F A

    2014-01-01

    Electron Cyclotron Emission (ECE) of different frequencies originates at different locations in non-uniformly magnetized plasmas. For simultaneous observation of multiple ECE frequencies from the outside edge of a toroidal plasma confinement device (e.g. a tokamak), the focal length of the collecting optics should increase with the frequency to maximize the resolution on a line of sight along the magnetic field gradient. Here we present the design and numerical study of a zoned metamaterial lens with such characteristics, for possible deployment with the 83-130 GHz ECE radiometer in the DIII-D tokamak. The lens consists of a concentric array of miniaturized element phase-shifters. These were reverse-engineered starting from the desired Gaussian beam waist locations and further optimized to account for diffraction and finite-aperture effects that tend to displace the waist. At the same time we imposed high and uniform transmittance, averaged over all phase-shifters. The focal length is shown to increase from 1...

  15. Magneto-thermoelectric effects in the two-dimensional electron gas of a HgTe quantum well due to THz laser heating by cyclotron resonance absorption

    Science.gov (United States)

    Pakmehr, Mehdi; Bruene, Christoph; Buhmann, Hartmut; Molenkamp, Laurens; McCombe, Bruce

    2015-03-01

    HgTe quantum wells (QWs) have shown a number of interesting phenomena over the past 20 years, most recently the first two-dimensional topological insulating state. We have studied thermoelectric photovoltages of 2D electrons in a 6.1 nm wide HgTe quantum well induced by cyclotron resonance absorption (B = 2 - 5 T) of a focused THz laser beam. We have estimated thermo-power coefficients by detailed analysis of the beam profile at the sample surface and the photovoltage signals developed across various contacts of a large Hall bar structure at a bath temperature of 1.6 K. We obtain reasonable values of the magneto-thermopower coefficients. Work at UB was supported by NSF DMR 1008138 and the Office of the Provost, and at the University of Wuerzburg by DARPA MESO Contract N6601-11-1-4105, by DFG Grant HA5893/4-1 within SPP 1666 and the Leibnitz Program, and the EU ERC-AG Program (Project 3-TOP.

  16. Effect of F- and CH-Doped on Dielectric Properties of SiCOH Films Deposited by Decamethylcyclopentasiloxane Electron Cyclotron Resonance Plasma

    Institute of Scientific and Technical Information of China (English)

    YE Chao; YU Xiao-Zhu; WANG Ting-Ting; NING Zhao-Yuan; XIN Yu; JIANG Mei-Fu

    2005-01-01

    @@ We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by decamethylcyclopentasiloxane (DMCPS) electron cyclotron resonance plasma. The dielectric constant k is closely related to the configurations of films. For thefilms deposited only using DMCPS, the minimum k is as low as2.88. By adding CH4 in the precursor, the k value can be reduced to 2.45 due to the film density decreasing by incorporating large size CHx groups. By adding CHF3 in the precursor, the k value can also be reduced to 2.48due to the incorporation of the weak-polarization F atom. Thus the dielectric constant for SiCOH films depends on not only the film density but also the polarization of atoms. By increasing the film density or by reducing the polarization of atoms under the condition of a lower film density, the low dielectric constant SiCOH films can be obtained.

  17. Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions

    Science.gov (United States)

    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+, 40Ar8+, 129Xe30+, 209Bi33+, etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform.

  18. Operation of Lanzhou all permanent electron cyclotron resonance ion source No. 2 on 320 kV platform with highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W., E-mail: luwang@impcas.ac.cn [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, J. Y.; Kang, L.; Liu, H. P.; Li, H.; Li, J. D.; Sun, L. T.; Ma, X. W. [Institute of Modern Physics, CAS, Lanzhou 730000 (China)

    2014-02-15

    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{sup +}, {sup 40}Ar{sup 8+}, {sup 129}Xe{sup 30+}, {sup 209}Bi{sup 33+}, etc. This paper will present the latest result of LAPECR2 and the routine operation status for the high voltage platform.

  19. Ion Behavior and Gas Mixing in electron cyclotron resonance plasmas as sources of highly charged ions (concept

    NARCIS (Netherlands)

    Melin, G.; Drentje, A. G.; Girard, A.; Hitz, D.

    1999-01-01

    Abstract: An ECR ion source is basically an ECR heated plasma confinement machine, with hot electrons and cold ions. The main parameters of the ion population have been analyzed, including temperature, losses, and confinement time. The "gas mixing" effect has been studied in this context. An express

  20. Ion Behavior and Gas Mixing in electron cyclotron resonance plasmas as sources of highly charged ions (concept

    OpenAIRE

    Melin, G.; Drentje, A. G.; Girard, A; Hitz, D.

    1999-01-01

    Abstract: An ECR ion source is basically an ECR heated plasma confinement machine, with hot electrons and cold ions. The main parameters of the ion population have been analyzed, including temperature, losses, and confinement time. The "gas mixing" effect has been studied in this context. An expression is derived for determining the ion temperature from the values of all extracted ion currents. One aim is to study the ion temperature behavior in argon plasmas without and with mixing different...

  1. A hybrid electron cyclotron resonance metal ion source with integrated sputter magnetron for the production of an intense Al{sup +} ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Philipp, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

    2015-09-15

    A metal ion source prototype has been developed: a combination of magnetron sputter technology with 2.45 GHz electron cyclotron resonance (ECR) ion source technology—a so called magnetron ECR ion source (MECRIS). An integrated ring-shaped sputter magnetron with an Al target is acting as a powerful metal atom supply in order to produce an intense current of singly charged metal ions. Preliminary experiments show that an Al{sup +} ion current with a density of 167 μA/cm{sup 2} is extracted from the source at an acceleration voltage of 27 kV. Spatially resolved double Langmuir probe measurements and optical emission spectroscopy were used to study the plasma states of the ion source: sputter magnetron, ECR, and MECRIS plasma. Electron density and temperature as well as Al atom density were determined as a function of microwave and sputter magnetron power. The effect of ECR heating is strongly pronounced in the center of the source. There the electron density is increased by one order of magnitude from 6 × 10{sup 9} cm{sup −3} to 6 × 10{sup 10} cm{sup −3} and the electron temperature is enhanced from about 5 eV to 12 eV, when the ECR plasma is ignited to the magnetron plasma. Operating the magnetron at constant power, it was observed that its discharge current is raised from 1.8 A to 4.8 A, when the ECR discharge was superimposed with a microwave power of 2 kW. At the same time, the discharge voltage decreased from about 560 V to 210 V, clearly indicating a higher plasma density of the MECRIS mode. The optical emission spectrum of the MECRIS plasma is dominated by lines of excited Al atoms and shows a significant contribution of lines arising from singly ionized Al. Plasma emission photography with a CCD camera was used to prove probe measurements and to identify separated plasma emission zones originating from the ECR and magnetron discharge.

  2. Photoelectron Emission from Metal Surfaces Induced by Radiation Emitted by a 14 GHz Electron Cyclotron Resonance Ion Source

    CERN Document Server

    Laulainen, Janne; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2015-01-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10 % of the estimated total electron losses from the plasma.

  3. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    Laulainen, Janne; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli

    2016-02-01

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  4. Photoelectron emission from metal surfaces induced by radiation emitted by a 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Laulainen, Janne, E-mail: janne.p.laulainen@student.jyu.fi; Kalvas, Taneli; Koivisto, Hannu; Komppula, Jani; Kronholm, Risto; Tarvainen, Olli [Department of Physics, University of Jyvaskyla, P.O. Box 35, FI-40014 Jyvaskyla (Finland)

    2016-02-15

    Photoelectron emission measurements have been performed using a room-temperature 14 GHz ECR ion source. It is shown that the photoelectron emission from Al, Cu, and stainless steel (SAE 304) surfaces, which are common plasma chamber materials, is predominantly caused by radiation emitted from plasma with energies between 8 eV and 1 keV. Characteristic X-ray emission and bremsstrahlung from plasma have a negligible contribution to the photoelectron emission. It is estimated from the measured data that the maximum conceivable photoelectron flux from plasma chamber walls is on the order of 10% of the estimated total electron losses from the plasma.

  5. The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source.

    Science.gov (United States)

    Tarvainen, O; Orpana, J; Kronholm, R; Kalvas, T; Laulainen, J; Koivisto, H; Izotov, I; Skalyga, V; Toivanen, V

    2016-09-01

    The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O(3+)-O(7+) were recorded at various tuner positions and frequencies in the range of 14.00-14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited "mode-hopping" between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.

  6. The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    Tarvainen, O.; Orpana, J.; Kronholm, R.; Kalvas, T.; Laulainen, J.; Koivisto, H.; Izotov, I.; Skalyga, V.; Toivanen, V.

    2016-09-01

    The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O3+-O7+ were recorded at various tuner positions and frequencies in the range of 14.00-14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited "mode-hopping" between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.

  7. Metamaterial Lens of Specifiable Frequency-Dependent Focus and Adjustable Aperture for Electron Cyclotron Emission in the DIII-D Tokamak

    Science.gov (United States)

    Hammond, K. C.; Massidda, S. D.; Capecchi, W. J.; Volpe, F. A.

    2013-08-01

    Electron Cyclotron Emission (ECE) of different frequencies originates at different locations in non-uniformly magnetized plasmas. For simultaneous observation of multiple ECE frequencies from the outside edge of a toroidal plasma confinement device (e.g. a tokamak), the focal length of the collecting optics should increase with the frequency to maximize the resolution on a line of sight along the magnetic field gradient. Here we present the design and numerical study of a zoned metamaterial lens with such characteristics, for possible deployment with the 83-130 GHz ECE radiometer in the DIII-D tokamak. The lens consists of a concentric array of miniaturized element phase-shifters. These were reverse-engineered starting from the desired Gaussian beam waist locations and further optimized to account for diffraction and finite-aperture effects that tend to displace the waist. At the same time we imposed high and uniform transmittance, averaged over all phase-shifters. The focal length is shown to increase from 1.32 m to 2.08 m over the frequency range of interest, as desired for low-field DIII-D discharges (B = -1.57 T). Retracting the lens to receded positions rigidly moves the waists accordingly, resulting in a good match—within a fraction of the Rayleigh length—of the EC-emitting layer positions at higher fields (up to B= -2.00 T). Further, it is shown how varying the lens aperture might move the waists "non-rigidly" to better match the non-rigid movement of the EC-emitting layers with the magnetic field. The numerical method presented is very general and can be used to engineer any dependence of the focal length on the frequency, including zero or minimal chromatic aberration.

  8. Anisotropic high-k deposition for gate-last processing of metal-oxide-semiconductor field-effect transistor utilizing electron-cyclotron-resonance plasma sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Yoshiaki, E-mail: kikuchi.y.ao@m.titech.ac.jp; Gao, Jun; Sano, Takahiro; Ohmi, Shun-ichiro, E-mail: ohmi@ep.titech.ac.jp

    2012-01-31

    A high-k/metal gate structure has been investigated for application to state-of-the-art metal-oxide-semiconductor field-effect transistors. In the high-k/metal gate structure, the 32-nm technology node was realized by using the high-k-last, metal-last integration process. We investigated anisotropic deposition for 3-dimensional gate structures on Si substrates utilizing electron-cyclotron-resonance plasma sputtering to reduce parasitic capacitance. Anisotropic HfN film deposition was realized and the deposition thickness on the side wall was reduced with decreasing sputtering gas pressure, from 0.15 to 0.06 Pa, corresponding to Ar/N{sub 2} flow ratios of 20/1 and 5/1 sccm. The HfSiON gate insulator formed from the anisotropically deposited HfN film showed an equivalent-oxide-thickness of 2.1 nm and a gate leakage of 3.1 Multiplication-Sign 10{sup -6}A/cm{sup 2} at V{sub FB}-1.0. - Highlights: Black-Right-Pointing-Pointer High-k film deposition was controlled by the deposition pressure. Black-Right-Pointing-Pointer The pressure decreases with a reduction of gas flow rate during the high-k film deposition. Black-Right-Pointing-Pointer A flat band voltage shows negative shifts with reduction of gas flow rates. Black-Right-Pointing-Pointer A reason of the flat band voltage shift is an increase in Si-N bonding.

  9. The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, O., E-mail: olli.tarvainen@jyu.fi; Orpana, J.; Kronholm, R.; Kalvas, T.; Laulainen, J.; Koivisto, H. [Department of Physics (JYFL), University of Jyväskylä, 40500 Jyväskylä (Finland); Izotov, I.; Skalyga, V. [Institute of Applied Physics, RAS, 46 Ul’yanova St., 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., 603950 Nizhny Novgorod (Russian Federation); Toivanen, V. [European Organization for Nuclear Research (CERN), 1211 Geneva 23 (Switzerland)

    2016-09-15

    The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O{sup 3+}–O{sup 7+} were recorded at various tuner positions and frequencies in the range of 14.00–14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited “mode-hopping” between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.

  10. Synchro-cyclotron

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    The electromagnetic coil which forms the first section of the proton extraction channel in the improved synchro-cyclotron. The photograph shows the positioning gear and the current septum. An extraction efficiency above 50% is expected.

  11. The new cyclotrons

    CERN Multimedia

    Lawson, J D

    1966-01-01

    Article describing how valuable scientific work can still be carried out with the smaller energy cyclotrons such as those at the Radiochemical Centre, Amersham and the Atomic Energy Research Establishment, Harwell (2 pages).

  12. Effect of minimum strength of mirror magnetic field (B sub m sub i sub n) on production of highly charged heavy ions from RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source (RAMSES)

    CERN Document Server

    Arai, H; Lee, S M; Higurashi, Y; Nakagawa, T; Kidera, M; Kageyama, T; Kase, M; Yano, Y; Aihara, T

    2002-01-01

    We measured the beam intensity of highly charged heavy ions (O, Ar and Kr ions) as a function of the minimum strength of mirror magnetic field (B sub m sub i sub n) of the RIKEN liquid-He-free super conducting electron-cyclotron resonance ion source. In this experiment, we found that the optimum value of B sub m sub i sub n exists to maximize the beam intensity of highly charged heavy ions and the value was almost the same (approx 0.49 T) for various charge state heavy ions.

  13. Cyclotron resonance absorption in ionospheric plasma

    Energy Technology Data Exchange (ETDEWEB)

    Villalon, E. (Northeastern Univ., Boston, MA (USA) Geophysics Lab., Hanscom AFB, MA (USA))

    1991-04-01

    The mode conversion of ordinary polarized electromagnetic waves into electrostatic cyclotron waves in the inhomogeneous ionospheric plasma is investigated. Near resonance the warm plasma dispersion relation is a function of the angle {theta} between the geomagnetic field and the density gradient and of the wave frequency {omega}, where {Omega} {le} {omega} {le} 2{Omega} and {Omega} is the electron cyclotron frequency. The differential equations describing the electric field amplitudes near the plasma resonance are studied, including damping at the second gyroharmonic. For certain values of {omega} and {theta} (e.g., {theta} < 45{degree}, {omega} {approximately} 2{Omega}) the wave equations reduce to the parabolic cylinder equation. The energy transmission coefficients and power absorbed by the cyclotron waves are calculated. The vertical penetration of the plasma wave amplitudes is iestimated using a WKB analysis of the wave equation.

  14. Semi-classical quantum theory for cyclotron radiation

    Institute of Scientific and Technical Information of China (English)

    陈军锋; 邓劲松; 徐毅; 尤峻汉

    1997-01-01

    A semi-classical quantum theory of the cyclotron radiation of the nonrelativistic thermal electrons in a very strong magnetic field is presented.The basic formulae of the absorption coefficient of cyclotron resonance kv and the absorption (scattering) cross-section of cyclotron resonance σv have been derived under the quadrupole approximation.σv is an important quantity in the study of the "magnetic inverse-Compton scattering".It is shown that σv is greatly larger than the Thomson cross-sectron σT,which is important in discussing the magnetic inverse-Compton scattering of the relativistic electrons in a very strong magnetic field.

  15. Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. I. Compression-Driven Instabilities and the Electron Heating Mechanism

    CERN Document Server

    Sironi, Lorenzo

    2014-01-01

    In systems accreting well below the Eddington rate, the plasma in the innermost regions of the disk is collisionless and two-temperature, with the ions hotter than the electrons. Yet, whether a collisionless faster-than-Coulomb energy transfer mechanism exists in two-temperature accretion flows is still an open question. We study the physics of electron heating during the growth of ion velocity-space instabilities, by means of multi-dimensional particle-in-cell (PIC) simulations. A large-scale compression - embedded in a novel form of the PIC equations - continuously amplifies the field. This constantly drives a pressure anisotropy P_perp > P_parallel, due to the adiabatic invariance of the particle magnetic moments. We find that, for ion plasma beta values beta_i ~ 5-30 appropriate for the midplane of low-luminosity accretion flows, mirror modes dominate if the electron-to-proton temperature ratio is > 0.2, whereas if it is m_e/m_i - governed by the conservation of the magnetic moment in the growing fields ...

  16. Cyclotron Line Measurements with INTEGRAL

    Science.gov (United States)

    Pottschmidt, K.; Kreykenbohm, I.; Caballero, I.; Fritz, S.; Schoenherr, G.; Kretschmar, P.; Wilms, J.; McBride, V. A.; Suchy, S.; Rothschild, R. E.

    2008-01-01

    Due to its broadband energy coverage, INTEGRAL has made important contributions to observing and interpreting cyclotron lines, which are present in the 10-100 keV range of a sample of accreting pulsars. In these systems photons with energies fulfilling the resonance condition inelastically Compton scatter off electrons quantized in the accretion column above the neutron star's magnetic pole(s). This process gives rise to the broad, absorption-like lines or 'cyclotron resonant scattering features' (CRSF). The observed lines allow to directly measure the B-fields of these sources, resulting in values of a few times 1E12G. In this overview I will present recent highlights regarding CRSF observations as well as discuss current ideas and models for the physical conditions in the accretion column. Among the former are the stability of the spectrum of Vela X-1 during giant flares in 2003, the observation of three cyclotron lines during the 2004 outburst of V0332+53, the confirmation of the fundamental line at approximately 45 keV during a 2005 normal outburst of A0535-26, and the simultaneous detection of the two lines in the dipping source 4U 1907+09 (for which also a torque reversal was detected for the first time). Through these and other observations it has become increasingly apparent that two types of observations can potentially be used to constrain the accretion column geometry: the determination of energy ratios for multiple harmonic lines (only two sources with greater than 2 lines are known), was well as the evolution of the fundamental line centroid, which, for different sources, may or may not be correlated with flux. Furthermore, first steps have been taken away from the usual phenomenological description of the lines, towards a physical approach based on self-consistent CRSF modeling. Initial applications are presented.

  17. Cyclotron Line Measurements with INTEGRAL

    Science.gov (United States)

    Pottschmidt, K.; Kreykenbohm, I.; Caballero, I.; Fritz, S.; Schoenherr, G.; Kretschmar, P.; Wilms, J.; McBride, V. A.; Suchy, S.; Rothschild, R. E.

    2008-01-01

    Due to its broadband energy coverage, INTEGRAL has made important contributions to observing and interpreting cyclotron lines, which are present in the 10-100 keV range of a sample of accreting pulsars. In these systems photons with energies fulfilling the resonance condition inelastically Compton scatter off electrons quantized in the accretion column above the neutron star's magnetic pole(s). This process gives rise to the broad, absorption-like lines or 'cyclotron resonant scattering features' (CRSF). The observed lines allow to directly measure the B-fields of these sources, resulting in values of a few times 1E12G. In this overview I will present recent highlights regarding CRSF observations as well as discuss current ideas and models for the physical conditions in the accretion column. Among the former are the stability of the spectrum of Vela X-1 during giant flares in 2003, the observation of three cyclotron lines during the 2004 outburst of V0332+53, the confirmation of the fundamental line at approximately 45 keV during a 2005 normal outburst of A0535-26, and the simultaneous detection of the two lines in the dipping source 4U 1907+09 (for which also a torque reversal was detected for the first time). Through these and other observations it has become increasingly apparent that two types of observations can potentially be used to constrain the accretion column geometry: the determination of energy ratios for multiple harmonic lines (only two sources with greater than 2 lines are known), was well as the evolution of the fundamental line centroid, which, for different sources, may or may not be correlated with flux. Furthermore, first steps have been taken away from the usual phenomenological description of the lines, towards a physical approach based on self-consistent CRSF modeling. Initial applications are presented.

  18. Inflation and Cyclotron Motion

    CERN Document Server

    Greensite, Jeff

    2016-01-01

    We consider, in the context of a braneworld cosmology, the motion of the universe coupled to a four-form gauge field, with constant field strength, defined in higher dimensions. It is found, under rather general initial conditions, that in this situation there is a period of exponential inflation combined with cyclotron motion in the inflaton field space. The main effect of the cyclotron motion is that conditions on the flatness of the inflaton potential, which are typically necessary for exponential inflation, can be evaded. There are Landau levels associated with the four-form gauge field, and these correspond to quantum excitations of the inflaton field.

  19. Dual-Array Electron Cyclotron Emission Imaging (ECEI): a New Millimeter Wave Imaging System for Electron Temperature Fluctuation on the DIII-D Tokamak

    Science.gov (United States)

    Luhmann, N. C., Jr.; Tobias, B. J.; Domier, C. W.; Kong, X.; Liang, T.; Jaspers, R.; Donne, A. J. H.; Smith, M.; Nazikian, R.; Park, H. K.

    2009-11-01

    A new diagnostic tool has been developed for simultaneous real-time imaging of electron temperature fluctuations at both the high and low field sides. Separate imaging arrays spanning 75 to 110 and 90 to 140 GHz, respectively consist of 160 channels (20 vertical by 8 radial) with ˜1 cm^2 resolution, providing up to 55 cm of vertical plasma coverage. Fluctuations of 1% are measurable on μs time-scales. The technical capabilities of this diagnostic, as well as potential physics issues to be investigated, are discussed. The details of the constituent technologies, including advanced antennas and substrate lenses, quasi-optical planar filter components, and double down-conversion heterodyne signal detection will be addressed.

  20. Roles of Fast-Cyclotron and Alfven-Cyclotron Waves for the Multi-Ion Solar Wind

    CERN Document Server

    Xiong, Ming

    2012-01-01

    Using linear Vlasov theory of plasma waves and quasi-linear theory of resonant wave-particle interaction, the dispersion relations and the electromagnetic field fluctuations of fast and Alfven waves are studied for a low-beta multi-ion plasma in the inner corona. Their probable roles in heating and accelerating the solar wind via Landau and cyclotron resonances are quantified. We assume that (1) low-frequency Alfven and fast waves have the same spectral shape and the same amplitude of power spectral density; (2) these waves eventually reach ion cyclotron frequencies due to a turbulence cascade; (3) kinetic wave-particle interaction powers the solar wind. The existence of alpha particles in a dominant proton/electron plasma can trigger linear mode conversion between oblique fast-whistler and hybrid alpha-proton cyclotron waves. The fast-cyclotron waves undergo both alpha and proton cyclotron resonances. The alpha cyclotron resonance in fast-cyclotron waves is much stronger than that in Alfven-cyclotron waves. ...

  1. The Warsaw K=160 cyclotron

    Science.gov (United States)

    Choinski, J.; Miszczak, J.; Sura, J.

    2001-12-01

    The overview of the Warsaw cyclotron facility is presented. The facility consists of K=160 cyclotron, 10 GHz ECR ion source, and several experimental stations. The cyclotron is of compact design with 2 straight dees. A yearly operation time is about 2900 hours on an average for the past few years. The cyclotron can deliver beams up to Ar with energy up to 10 MeV/amu to the experimental area. Experimental stations are: 1) The multidetector OSIRIS II, allows the study of exotic nuclei in the double magic 100Sn region. The experimental set-up consists of 8 HPGe detectors equipped with charged particle 4π multiplicity filter SiBall, 50 elements BGO γ-rays multiplicity filter, 4 sector polarimeter and electron conversion detector system. 2) CUDAC-Coulomb Universal Detector Scattering Chamber-an array of PIN-diodes in connection with HPGe detectors and the computer data analysis package GOSIA, maintained by the Laboratory allows investigation the Coulomb Excitation (COULEX) reactions. 3) IGISOL or Helium-jet transport system opened investigation of the reaction products by means of the online mass separator with ion-guide system. The system uses the Scandinavian-type mass separator built in INR Świerk, Poland. 4) Giant Dipole Resonance studies using experimental set-up JANOSIK developed for the detection of high-energy photons emitted in heavy-ion collisions. The set-up consists of a large NaI(Tl) detector (25 cm×29 cm) surrounded by shields: passive lead shield, active anticoincidence plastic shield and LiH shield to absorb neutrons, and a multiplicity filter of 32 small scintillator detectors (BaF2 and NaI(Tl)). 5) Laser spectroscopy stand now in test phase. The laser spectroscopy group at HIL has completed an equipment consisting of Argon ion Laser Innova 400-25W in all lines and coherent Ring Laser 669-21 as well as atomic beam apparatus.

  2. Effect of Quantizing Magnetic Field on Cyclotron Energy and Cyclotron Effective Mass in Size Quantized Films with Non-Parabolic Energy Band

    Institute of Scientific and Technical Information of China (English)

    B.(I). GUL(I)YEV; R. F. EM(I)NBEYL(I); A. KORKUT

    2007-01-01

    The Fermi energy, cyclotron energy and cyclotron effective mass of degenerate electron gas in a size-quantized semiconductor thin film with non-parabolic energy bands are studied. The influences of quantizing magnetic field on these quantities in two-band approximation of the Kane model are investigated. It is shown that the Fermi energy oscillates in a magnetic field. The period and positions of these oscillations are found as a function of film thickness and concentration of electrons. Cyclotron energy and cyclotron effective mass are investigated as a function of film thickness in detail. The results obtained here are compared with experimental data on GaAs quantum wells.

  3. Upgrading Synchro-cyclotron

    CERN Multimedia

    1974-01-01

    Final touches to the central region of SC2, the refurbished 600 MeV synchro-cyclotron, before the start of commissioning. Modifications included a new type of ion source at the centre. Protons were first accelerated in SC2 at full energy by October 1974. (See photo 7408042X)

  4. ECR Ion Source for a High-Brightness Cyclotron

    Science.gov (United States)

    Comeaux, Justin; McIntyre, Peter; Assadi, Saeed

    2011-10-01

    New technology is being developed for high-brightness, high-current cyclotrons with performance benefits for accelerator-driven subcritical fission power, medical isotope production, and proton beam cancer therapy. This paper describes the design for a 65 kV electron cyclotron resonance (ECR) ion source that will provide high-brightness beam for injection into the cyclotron. The ion source is modeled closely upon the one that is used at the Paul Scherrer Institute. Modifications are being made to provide enhanced brightness and compatibility for higher-current operation.

  5. Cyclotron Line Variability

    CERN Document Server

    Mihara, Tatehiro; Nagase, Fumiaki

    2014-01-01

    We systematically analyzed the spectra of X-ray binary pulsars observed with GINGA (Mihara 1995). A new model NPEX (Negative and Positive power-laws EXponential) was introduced t o represent the pulsar continuum. Combining the NPEX continuum with the CYAB factor (cyclotron resonance scattering model), we successfully fit the whole-band spectra of all the pulsars. A possible physical meaning of the NPEX model is the Comptonized spectra. By using the smooth and concave NPEX model, the cyclotron structures were detected from 12 pulsars, about a half of the 23 sources, including new discoveries from LMC X-4 and GS 1843+00. The magnetic fields were scattered in the range of $3\\times10^{11}$ - $5\\times10^{12}$ G. The distribution was shown for the first time, which is remarkably similar to that of radio pulsars with a peak at $2 \\times 10^{12}$ G. The double harmonic cyclotron structures of 4U 0115+63 in 1990 changed to a sin gle structure in 1991. The resonance energy also increased by 40 % as the luminosity decre...

  6. 电子回旋共振放电电离特性的PIC/MCC模拟%PIC/MCC Simulation of the Ionizing Characters in Electron Cyclotron Resonance Discharge

    Institute of Scientific and Technical Information of China (English)

    金晓林; 杨中海

    2007-01-01

    A theoretical and computational model is presented to study the ionization of the argon electron cyclotron resonance(ECR)microwave discharge using a quasi-three-dimensional electromagnetic particle-in-cell plus Monte Carlo collision method.The interaction between the charged particles and microwave fields are described by the electromagnetic mode of particle-in-cell method.The collision processes are treated with Monte Carlo method.The simulation code is the original work.The results of the particle simulation for the ECR discharge of argon gas which include the microscopic features of charged particles and the electromagnetic characteristics of the ECR discharge plasma,and also the transient phenomena have been presented.

  7. Transparency of Magnetized Plasma at Cyclotron Frequency

    Energy Technology Data Exchange (ETDEWEB)

    G. Shvets; J.S. Wurtele

    2002-03-14

    Electromagnetic radiation is strongly absorbed by a magnetized plasma if the radiation frequency equals the cyclotron frequency of plasma electrons. It is demonstrated that absorption can be completely canceled in the presence of a magnetostatic field of an undulator or a second radiation beam, resulting in plasma transparency at the cyclotron frequency. This effect is reminiscent of the electromagnetically induced transparency (EIT) of the three-level atomic systems, except that it occurs in a completely classical plasma. Unlike the atomic systems, where all the excited levels required for EIT exist in each atom, this classical EIT requires the excitation of the nonlocal plasma oscillation. The complexity of the plasma system results in an index of refraction at the cyclotron frequency that differs from unity. Lagrangian description was used to elucidate the physics and enable numerical simulation of the plasma transparency and control of group and phase velocity. This control naturally leads to applications for electromagnetic pulse compression in the plasma and electron/ion acceleration.

  8. Cyclotrons and positron emitting radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A.P.; Fowler, J.S.

    1984-01-01

    The state of the art of Positron Emission Tomography (PET) technology as related to cyclotron use and radiopharmaceutical production is reviewed. The paper discusses available small cyclotrons, the positron emitters which can be produced and the yields possible, target design, and radiopharmaceutical development and application. 97 refs., 12 tabs. (ACR)

  9. Ion-Beam-Excited Electrostatic Ion Cyclotron Instability

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1977-01-01

    The stability limits of the ion‐beam‐excited, electrostatic, ion cyclotron instability were investigated in a Q‐machine plasma where the electrons could be heated by microwaves. In agreement with theory, the beam energy necessary for excitation decreased with increasing electron temperature....

  10. Ion-Beam-Excited, Electrostatic, Ion Cyclotron Instability

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1977-01-01

    The stability limits of the ion‐beam‐excited, electrostatic, ion cyclotron instability were investigated in a Q‐machine plasma where the electrons could be heated by microwaves. In agreement with theory, the beam energy necessary for excitation decreased with increasing electron temperature....

  11. V.U.V. plasma spectroscopy diagnostic of electron cyclotron resonance multicharged ion sources; Diagnostic de plasmas crees dans des sources d'ions multicharges a resonance cyclotronique electronique par spectroscopie V.U.V

    Energy Technology Data Exchange (ETDEWEB)

    Berreby, R

    1997-12-15

    To characterize the multicharged ions within the plasma of an E.C.R. ion source, the V.U.V. spectroscopy is used as a non invasive diagnostic of excited matter. In E.C.R.I. S. (electron cyclotron resonance ion source) electrons are heated and magnetically confined within the mirror machine to overcome the successive ionization potentials of the desired elements. As the electrons bounce inside the magnetic configuration in their gyration movement, they interact with the microwaves injected into the source at the resonance frequency. To enhance the performances in high charge states and extracted currents delivered by E.C.R.I.S., the fundamental parameters of the plasma created in these machines must be known. The goal of spectroscopic diagnostics in the V.U.V. range installed on the sources is to determine electron density and temperature on one hand, and the ionic densities and confinement time on the other hand. We used microchannel plates as detector on a 3 meter grazing incidence spectrometer equipped with a 600 lines/mm holographic grating. The calibration of the whole grating with detector was performed by two different methods. These are the branching ratio and charge exchange methods. Identification of lines emitted by a plasma, which gather the whole charge states of ions is necessary to make an exhaustive study of the plasma state. And finally, the determination of plasma parameters like electron density and temperature and ion densities and confinement times that uses theoretical models were the aim of this work. (author)

  12. Note: theoretical study on the gas pressure dependence of x-ray yield in TE(111) cavity based electron cyclotron resonance x-ray source.

    Science.gov (United States)

    Selvakumaran, T S; Sen, Soubhadra; Baskaran, R

    2014-11-01

    Adopting Langevin methodology, a pressure dependent frictional force term which represents the collisional effect is added to the Lorentz equation. The electrons are assumed to be starting from the uniformly distributed co-ordinates on the central plane. The trajectory of each electron is numerically simulated by solving the modified Lorentz equation for a given pressure. The Bremsstrahlung x-ray energy spectrum for each electron crossing the cavity wall boundary is obtained using the Duane-Hunt law. The total x-ray yield is estimated by adding the spectral contribution of each electron. The calculated yields are compared with the experimental results and a good agreement is found.

  13. BEST medical radioisotope production cyclotrons

    Science.gov (United States)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Gelbart, W. Z.; Johnson, Richard R.

    2013-04-01

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 μA to 1000 μA, depending on the cyclotron energy and application [1].

  14. Spiral Inflector For Compact Cyclotron

    CERN Document Server

    Karamysheva, G A

    2004-01-01

    Compact cyclotron for explosives detection by nuclear resonance absorption of γ-rays in nitrogen is under development [1] Cyclotron will be equipped with the external ion source. The injection system consists of a double-drift beam bunching system, a spiral inflector, beam diagnostics, focusing and adjustment elements [2]. The spiral inflector for ion bending from axial to median plane is used. Computer model of spiral inflector for the Customs cyclotron is developed. 3D electrostatic field calculations of the designed inflector are performed. Calculated electric field map and magnetic field map of the cyclotron [3] are used for beam dynamic simulations. Numeric simulations are carried out for 500 particles using code for calculation of particle dynamics by integration of differential equations in Cartesian coordinate system written in MATLAB. Direct Coulomb particle-to-particle method is used to take into account space-charge effects.

  15. Ion Cyclotron Resonance Facility (ICR)

    Data.gov (United States)

    Federal Laboratory Consortium — his facility is charged with developing and exploiting the unique capabilities of Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, and leads the...

  16. Hydrogen negative ion production in a 14 GHz electron cyclotron resonance compact ion source with a cone-shaped magnetic filter

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, T.; Kasuya, T.; Wada, M., E-mail: mwada@mail.doshisha.ac.jp [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto (Japan); Kenmotsu, T. [School of Biomedical Sciences, Doshisha University, Kyotanabe, Kyoto (Japan); Maeno, S. [Novelion Systems Co. Ltd., Kyotanabe, Kyoto (Japan); Nishiura, M.; Shimozuma, T. [National Institute for Fusion Science, Toki, Gifu (Japan); Yamaoka, H. [RIKEN SPring-8 Center, Sayo, Hyogo (Japan)

    2014-02-15

    The plasma electrode structure of a 14 GHz ECR ion source was modified to enlarge the plasma volume of low electron temperature region. The result shows that the extracted beam current reached about 0.6 mA/cm{sup 2} with about 40 W microwave power. To investigate the correlation between the volume of the low electron temperature region and the H{sup −} current, a vacuum ultraviolet (VUV) spectrometer had been installed to observe light emission in the VUV wavelength range from the plasma. From the results of the negative ion beam current and that from VUV spectrometry, production rate of vibrationally excited hydrogen molecule seems to be enhanced by increasing the volume of low electron temperature region.

  17. Hydrogen negative ion production in a 14 GHz electron cyclotron resonance compact ion source with a cone-shaped magnetic filter.

    Science.gov (United States)

    Ichikawa, T; Kasuya, T; Kenmotsu, T; Maeno, S; Nishiura, M; Shimozuma, T; Yamaoka, H; Wada, M

    2014-02-01

    The plasma electrode structure of a 14 GHz ECR ion source was modified to enlarge the plasma volume of low electron temperature region. The result shows that the extracted beam current reached about 0.6 mA/cm(2) with about 40 W microwave power. To investigate the correlation between the volume of the low electron temperature region and the H(-) current, a vacuum ultraviolet (VUV) spectrometer had been installed to observe light emission in the VUV wavelength range from the plasma. From the results of the negative ion beam current and that from VUV spectrometry, production rate of vibrationally excited hydrogen molecule seems to be enhanced by increasing the volume of low electron temperature region.

  18. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  19. Effect of frequency tuning on bremsstrahlung spectra, beam intensity, and shape in the 10 GHz NANOGAN electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, G., E-mail: gerosro@gmail.com; Mal, Kedar; Kumar, Narender; Lakshmy, P. S.; Mathur, Y.; Kumar, P.; Kanjilal, D.; Roy, A. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India); Baskaran, R. [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)

    2014-02-15

    Studies on the effect of the frequency tuning on the bremsstrahlung spectra, beam intensities, and beam shape of various ions have been carried out in the 10 GHz NANOGAN ECR ion source. The warm and cold components of the electrons were found to be directly correlated with beam intensity enhancement in case of Ar{sup 9+} but not so for O{sup 5+}. The warm electron component was, however, much smaller compared to the cold component. The effect of the fine tuning of the frequency on the bremsstrahlung spectrum, beam intensities and beam shape is presented.

  20. Generation of multi-charged high current ion beams using the SMIS 37 gas-dynamic electron cyclotron resonance (ECR) ion source

    Energy Technology Data Exchange (ETDEWEB)

    Dorf, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zorin, V. G. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Sidorov, A. V. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Bokhanov, A. F. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Izotov, I. V. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Razin, S. V. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Skalyga, V. A. [Russian Academy of Sciences (RAS), Nizhny Novgorod (Russian Federation). Inst. of Applied Physics

    2013-06-02

    A gas-dynamic ECR ion source (GaDIS) is distinguished by its ability to produce high current and high brightness beams of moderately charged ions. Contrary to a classical ECR ion source where the plasma confinement is determined by the slow electron scattering into an empty loss-cone, the higher density and lower electron temperature in a GaDIS plasma lead to an isotropic electron distribution with the confinement time determined by the prompt gas-dynamic flow losses. As a result, much higher ion fluxes are available, however a decrease in the confinement time of the GaDIS plasma lowers the ion charge state. The gas-dynamic ECR ion source concept has been successfully realized in the SMIS 37 experimental facility operated at the Institute of Applied Physics, Russia. The use of high-power (~100 kW) microwave (37.5 GHz) radiation provides a dense plasma (~1013 cm-3) with a relatively low electron temperature (~50- 100 eV) and allows for the generation of high current (~1 A/cm2) beams of multi-charged ions. In this work we report on the present status of the SMIS 37 ion source and discuss the advanced numerical modeling of ion beam extraction using the particle-in-cell code WARP

  1. Generation of multi-charged high current ion beams using the SMIS 37 gas-dynamic electron cyclotron resonance (ECR) ion source

    Energy Technology Data Exchange (ETDEWEB)

    Dorf, M.A., E-mail: dorf1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Zorin, V.G.; Sidorov, A.V.; Bokhanov, A.F.; Izotov, I.V.; Razin, S.V.; Skalyga, V.A. [Institute of Applied Physics RAS, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)

    2014-01-01

    A gas-dynamic ECR ion source (GaDIS) is distinguished by its ability to produce high current and high brightness beams of moderately charged ions. Contrary to a classical ECR ion source where the plasma confinement is determined by the slow electron scattering into an empty loss-cone, the higher density and lower electron temperature in a GaDIS plasma lead to an isotropic electron distribution with the confinement time determined by the prompt gas-dynamic flow losses. As a result, much higher ion fluxes are available; however a decrease in the confinement time of the GaDIS plasma lowers the ion charge state. The gas-dynamic ECR ion source concept has been successfully realized in the SMIS 37 experimental facility operated at the Institute of Applied Physics, Russia. The use of high-power (∼100 kW) microwave (37.5 GHz) radiation provides a dense plasma (∼10{sup 13} cm{sup −3}) with a relatively low electron temperature (∼50–100 eV) and allows for the generation of high current (∼1 A/cm{sup 2}) beams of multi-charged ions. In this work we report on the present status of the SMIS 37 ion source and discuss the advanced numerical modeling of ion beam extraction using the particle-in-cell code WARP.

  2. Resonant cyclotron scattering in magnetars' emission

    CERN Document Server

    Rea, Nanda; Turolla, Roberto; Lyutikov, Maxim; Gotz, Diego

    2008-01-01

    We present a systematic application of a resonant cyclotron scattering (RCS) model to a comprehensive set of magnetars, including canonical and transient anomalous X-ray pulsars, and soft gamma repeaters. In this scenario, non-thermal magnetar spectra in the soft X-rays (i.e. below ~10keV) result from resonant cyclotron scattering of the thermal surface emission by hot magnetospheric plasma. We find that this model can successfully account for the X-ray emission of magnetars, while using the same number of free parameters than the commonly used empirical blackbody plus power-law model. We find that the entire class of sources is characterized by magnetospheric plasma with similar properties, in particular the optical depth is in a quite narrow range (tau_{res} ~1-2). This leads to an estimate of the magnetospheric electron densities at the resonance n_e ~ 1.5x10^{13} tau_{res} cm^{-3}, which is 3 orders of magnitudes greater than n_{GJ}, the Goldreich-Julian electron density for pulsar magnetospheres. The inf...

  3. Recent Progress in High Frequency Electron Cyclotron Resonance Ion Sources%高频ECR离子源的最新进展

    Institute of Scientific and Technical Information of China (English)

    D.Hitz

    2007-01-01

    As they are first optimized for their ion losses,ECRISs are always under a fundamental compromise:having high losses and strong confinement at the same time.To help ECR ion source developers in the design or improvement of existing machines,general comments are presented in a review article being soon published.In this 160 pages contribution,fundamental aspects of ECRISs are presented,with a discussion of electron temperature and confinement and ion confinement.Then,as microwaves play a key role in these machines,a chapter presents major guidelines for microwave launching and coupling to ECR plasma.Moreover,once ECR plasma is created,understanding this plasma is important in ion sourcery;and a section is dedicated to plasma diagnostics with an emphasis on the determination of electron and ion density and temperature by vacuum ultraviolet(VUV)spectroscopy.Another chapter deals with the role of magnetic confinement and presents updated scaling laws,Next chapter presents different types of ECRISs designed according to the main parameters previously described.Finally,some industrial applications of ECRISs and ECR plasmas in general are presented like ion implantation and photon lithography.Some hints taken from this review article are presented in the following article.

  4. CSIR cyclotron modified for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    National Accelerator Centre (NAC) staff members will be making an important contribution to radiation therapy in South Africa when the Transvaal Department of Hospital Services starts treating certain types of cancer with fast neutrons, at the Pretoria Cyclotron on the CSIR campus. The fast neutrons will be utilized mainly to treat advanced cancers of the head and the neck. The project will develop along two lines. Firstly the Pretoria cyclotron must be modified and secondly satisfactory radiobiological data must be provided before patients may be treated. This radiobiological experiment heralds a new area for use of the cyclotron which has thus far been used mainly for basic nuclear research and the production of isotopes.

  5. Use of cyclotrons in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Qaim, S.M. E-mail: s.m.qaim@fz-juelich.de

    2004-11-01

    Cyclotrons are versatile ion-accelerating machines which find many applications in medicine. In this short review their use in hadron therapy is briefly discussed. Proton therapy is gaining significance because of its capability to treat deep-lying tumours. A strong area of application of cyclotrons involves the production of short-lived neutron deficient radiotracers for use in emission tomography, especially positron emission tomography. This fast and quantitative in vivo diagnostic technique is being increasingly used in neurology, cardiology and oncology. Besides routine patient care, considerable interdisciplinary work on development of new positron emitters is under way. A short account of those efforts is given. The use of cyclotrons in the production of radionuclides for internal radiotherapy is also briefly described.

  6. MC-50 AVF cyclotron operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seok; Chai, Jong Seo; Bak, Seong Ki; Park, Chan Won; Jo, Young Ho; Hong, Seong Seok; Lee, Min Yong; Jang Ho Ha

    2000-01-01

    The first cyclotron in Korea, MC-50 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-60{mu}A. A total of beam extraction time are 1095.7 hours. 206.5 hours are used for the developments and 663.8 hours are for radionuclide production and development and 225.4 hours for application researches. The shutdown days are 23 days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed.

  7. Observation of cyclotron resonance and electron-phonon coupling in surface states of the bulk-insulating topological insulator Cu0.02Bi2Se3

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Liang [Johns Hopkins Univ., Baltimore, MD (United States). The Inst. of Quantum Matter; Tse, Wang-Kong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morris, C. M. [Johns Hopkins Univ., Baltimore, MD (United States). The Inst. of Quantum Matter; Brahlek, M. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy; Koirala, N. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy; Oh, S. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy; Armitage, N. P. [Johns Hopkins Univ., Baltimore, MD (United States). The Inst. of Quantum Matter

    2015-02-05

    We have utilized magneto-optical time-domain spectroscopy to investigate the low frequency optical response of topological insulator Cu0.02Bi2Se3 and Bi2Se3 films. With both field and frequency depedence, such experiments give sufficient information to measure the mobility and carrier density of multiple conduction channels simultaneously. We observe sharp cyclotron resonances (CRs) in both samples. The small amount of Cu substitution into the Cu0.02Bi2Se3 induces a true bulk insulator with only a single conduction channel with total sheet carrier density 4.9 x 1012/cm2 and mobility as large as 4000 cm2/V s. This is consistent with pure topological surface state (TSSs) conduction with a chemical potential 150 meV above the Dirac point. Hence, a true topological insulator with an insulating bulk is realized. The CR broadens at high fields, an e ect that we attribute to an electron-phonon interaction. This assignment is supported by an extended Drude model analysis on the zero field data. In contrast to Cu0.02Bi2Se3, two charge channels were observed in normal Bi2Se3 films. We demonstrate a method to distinguish between the dominant TSSs and trivial bulk/2DEG states. The dominant channel exhibits a CR with a carrier density of ~2.0 x 1013/cm2 and mobility ~3200 cm2/V s, consistent with TSSs with a chemical potential ~350meV above the Dirac point.

  8. Ion sources for cyclotron applications

    Energy Technology Data Exchange (ETDEWEB)

    Leung, K.N.; Bachman, D.A.; McDonald, D.S.; Young, A.T.

    1992-07-01

    The use of a multicusp plasma generator as an ion source has many advantages. The development of both positive and negative ion beams based on the multicusp source geometry is presented. It is shown that these sources can be operated at steady state or cw mode. As a result they are very suitable for cyclotron operations.

  9. Status report on cyclotron operation

    CERN Document Server

    Kovács, P; Ander, I; Lakatos, T; Fenyvesi, A; Ditrói, F; Takács, S; Tarkanyi, F

    2003-01-01

    The operation of the cyclotron in 2002 was concentrated to 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 4084 hours, the breakdown periods amounted to 15 hours last year. In order to improve the circumstances of the irradiations, several following improvements were done. (R.P.)

  10. Influence of Electron Cyclotron Resonance Plasma Etching on the Optical and Wetting Properties of Glass%ECR等离子体刻蚀对玻璃光学和润湿性能的影响

    Institute of Scientific and Technical Information of China (English)

    宋雪梅; 王亮; 陈宇; 孟祥曼; 王波; 严辉

    2015-01-01

    In order to improve the transmittance and self-cleaning properties of solar cell cover glass. The borosilicate glass was etched by electron cyclotron resonance ( ECR ) plasma etching with metal nanoparticles mask. The glass surface after etching was observed by scanning electron microscopy ( SEM ) . The change of the transmittance of the glass after etching was measured by the UV-VIS spectrophotometer. The wetting property of the bare and etching glass was determined by the contact angle instrument. The results show the mountainous structure was formed on glass substrate after ECR plasma etching,and its average size ranges from 80 nm to 140 nm. The visible light transmittance of the glass is effectively improved. It increases from 91% to 94. 4% with the bias etching. Moreover, It enhancs the hydrophilicity on the surface of the glass. The lower contact angle (θc) of 7. 4° is obtained compared to the bare glass substrate (θc~47. 2°). The self-cleaning properties are improved.%为了提高太阳能电池盖板玻璃的透过率和自清洁性能,采用电子回旋共振( ECR)等离子体刻蚀与金属颗粒掩膜结合的方法刻蚀硼硅酸盐玻璃,采用扫描电镜( SEM)对刻蚀后玻璃表面形貌进行了观察,采用分光光度计测量了刻蚀前后玻璃透过率变化,并用接触角仪测定了刻蚀前后玻璃表面润湿性变化. 结果表明:经过ECR等离子体刻蚀后,在玻璃表面形成多山峰状纳米结构,平均尺寸约在80~140 nm,并有效提高了玻璃的可见光透过率,尤其是在有偏压刻蚀后透过率由原来91%提高到94. 4%,同时,玻璃表面亲水性增强,接触角θc由原来的47. 2°变为7. 4°,自清洁性能得到提高.

  11. Plane gyroklinotron at first and third harmonics of cyclotron frequency

    Energy Technology Data Exchange (ETDEWEB)

    Kurayev, A.A.; Lukashonok, D.V.; Sinitsyn, A.K., E-mail: kurayev@bsuir.by, E-mail: timka86@gmail.com [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2011-07-01

    The results of gyroklinotron's parameters optimization for efficiency at f = 100 GHz with interaction on first and third harmonics of the cyclotron frequency are presented. The predicted electron gyroklinotron's efficiency reaches 70% on first harmonic and 40% on third harmonic. This is more than in usual gyrotron. Besides in contrast to usual gyrotron the width electron beam on radius of guiding centers of electron orbits in gyroklinotron may considerable exceed working wave length {lambda}. This allows to use in it considerable more power of electron beams EB then in usual gyrotron. (author)

  12. Surface crystallization of amorphous fused silica during electron cyclotron resonance plasma etching%非晶熔石英表面等离子体刻蚀过程中的表面晶化研究

    Institute of Scientific and Technical Information of China (English)

    王锋; 吴卫东; 蒋晓东; 唐永建

    2012-01-01

    本工作采用电子回旋共振(ECR)低压等离子体刻蚀技术,刻蚀非晶熔石英表面.Ar/CF_4为反应气体刻蚀后再经O等离子体钝化,非晶熔石英表面出现晶化现象.晶化层约几百纳米厚.Ar/CF_4在ECR的电磁场作用下产生F离子与C离子,F离子使熔石英表面的Si-O共价键断裂,并释放出O离子.C离了与O离子迅速键合生成CO_2,而被断键的Si原子与四个F原子键合生成气态SiF4.熔石英原始表面被去除的同时,在新的表面留下大量不饱和Si原子.不饱和Si原子在高温条件下被O等离子钝化,形成结晶态α方石英.%After low pressure fluorine plasma ecthing and oxygen ion passivation,a crystallized layer composed of SiO_2 nano-crystal grains is observed in an amorphous fused silica surface.The depth of crystallized layer is at least several hundreds nanometers.Fluorine and carbon ion are generated from Ar/CF_4 by the method of electron cyclotron resonance(ECR).F ion breaks Si-O band of initial silica surface layer and releases O ion.Carbon ion combines with oxygen ion,and turns into CO_2,and SiF_4 is generated from fluorine and silicon.After initial surface layer is removed,unsaturated Si atom remains.Si dangling bond recombines with new O ion and then creates crystallizedα-cristobalite nano-crystal grains under a high temperature.

  13. Non-inductive plasmas studies by injection of electron cyclotron waves in the Tore Supra tokamak; Etudes des plasmas non-inductifs par injection d'ondes a la frequence cyclotronique electronique dans le tokamak Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Turco, F

    2008-06-15

    In this work we addressed the issue of the phenomena typical of the non-inductive discharges in the Tore Supra tokamak, probed by means of localised perturbations of the current density profile, performed by electron cyclotron (EC) waves. In order to correctly utilize the current density profile, reconstructed by means of the CRONOS code we performed a sensitivity study on the code results. Concerning the MHD regimes we have shown that a dynamic evolution of the safety factor q which tends to shrink its profile appears to be the cause of the triggering of such regimes. From the operational point of view, deposing the EC current, generated in the same direction of the plasma current, outside the q{sub min} position results hazardous because it causes a rise in q{sub 0} and consequently the shrinking of the q profile which triggers the MHD regimes. On the contrary, the EC counter-current scans show that a very central deposition ({rho}(ECCD) < 0.1) lead almost certainly to an MHD regime, while a more external countercurrent generation has generally the quality of creating internal transport barriers (ITBs). The phenomenon of non-linear temperature oscillations (the O-regime) has also been addressed, to provide an analytical description as well as from the experimental point of view, concerning the triggering and canceling of the oscillating phases. By constructing a non-linear predator-prey system with noise, solved on two regions of space coupled by a diffusion term, we could reproduce the experimental temperature oscillations: this study allowed us to confirm that the oscillatory phenomenon is the manifestation of a Lotka-Volterra like coupling between j and T{sub e}. The experimental analysis led to the identification of the mechanism at the origin of the triggering and canceling of the O-regime in presence of a perturbation in a specific shape of magnetic shear perturbation. These results have been reproduced by the simulations preformed with the integrated

  14. Radiation Sources at Electron Cyclotron Harmonic Frequencies.

    Science.gov (United States)

    1983-01-28

    plane K1 2 K3 K 4 2 2 22-l PbQ1 P 401 E0 1 E01 Assume: a) K2 > 0.5, all n b) Pbl < Pb2 < Pb3 < C) Pthr < Pthrbl b2 0 Easy to show that if F1 = 0...bl < P b2 < P b3 < "’ C) Pthr < _thr b2 bl 0 Easy to show that if F2 = 0, then F1 = n1PbQ 1 1 - K 2 ] For infinitesimal E01 , it follows that F2 < 0

  15. Optically detected cyclotron resonance in a single GaAs/AlGaAs heterojunction

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, Gregor

    2011-09-23

    Optically detected far-infrared cyclotron resonance (FIR-ODCR) in GaAs/AlGaAs HJs is interpreted in the frame of an exciton-dissociation mechanism. It is possible to explain the ODR mechanism by an exciton drag, mediated by ballistically propagating phonons. Furthermore, very narrow resonances are presented and realistic electron mobility values can be calculated. The exceptionally narrow ODCRs allow to measure conduction-band nonparabolicity effects and resolve satellite resonances, close to the main cyclotron resonance line.

  16. The development of cyclotron radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Dae; Chun, K. W.; Suh, Y. S.; Lee, J. D.; Ahn, S. H. and others

    1999-03-01

    The purpose of this project is to developthe radiopharmaceuticals and automatic synthetic unit for labelled compounds, and to establish mass production system of radiopharmaceuticals. These will contribute to the early diagnosis of the disease hard to cure. The contents of this project are as follows, the development of the radiopharmaceutical for imaging of cancer, the development of automatic synthesizer for the synthesis of radio-pharmaceuticals, the development of hormone derivatives labelled with {sup 12}'3I, the development of the radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for therapy of cancer labelled with cyclotron produced radionuclides, the development of radiopharmaceuticals for imaging of myocardial metabolism.

  17. Cyclotron resonance studies on InAs/GaSb heterostructures

    CERN Document Server

    Petchsingh, C

    2002-01-01

    Far-infrared cyclotron resonance is used to study the magneto-optical properties of semimetallic InAs/GaSb heterostructures. Spatially separated two-dimensional electron and hole gases coexist in this 'broken-gap' type-ll system due to charge transfer across the interfaces. Hybridisations of the overlapping electron and hole wavefunctions are investigated experimentally in samples of varying growth parameters. A self-consistent 8-band k centre dot p model is used to assist in the interpretation of experimental results. In samples subjected to varying magnetic field, hybridisations result in oscillations of cyclotron resonance mass, amplitude and linewidth, accompanied by transition splittings in the vicinity of Landau level anticrossings. Asymmetries introduced by InSb interface biasing enhance these effects. Comparison of samples with varying confinement energies (at specified magnetic field) shows effective mass enhancement greater than the standard nonparabolicity effect. The mass enhancement increases wit...

  18. Commercial compact cyclotrons in the 90`s

    Energy Technology Data Exchange (ETDEWEB)

    Milton, B.F.

    1995-09-01

    Cyclotrons continue to be efficient accelerators for radio-isotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicate a strong future for commercial cyclotrons. In this paper the authors will survey recent developments in the areas of cyclotron technology, as they relate to the new generation of commercial cyclotrons. Design criteria for the different types of commercial cyclotrons will be presented, with reference to those demands that differ from those in a research oriented cyclotron project. The authors also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA.

  19. Method and apparatus for ion cyclotron spectrometry

    Science.gov (United States)

    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.

  20. Determination of electromagnetic modes in oversized corrugated waveguides on the electron cyclotron resonance heating installation at the tokamak Tore Supra; Determination de modes electromagnetiques de guides d'ondes corrugues surdimensionnes sur l'installation de chauffage des electrons de tokamak Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, L

    2001-03-09

    Electron cyclotron resonance heating (ECRH) in the Tore Supra tokamak constitutes an important step in the research aimed at obtaining thermonuclear fusion reactions. Electron heating is achieved by transmitting an electromagnetic wave from the oscillators (gyrotrons) to the plasma via the fundamental mode, propagating in oversized corrugated waveguides. Maximizing the proportion of the gyrotron power coupled to the fundamental waveguide mode is essential for the good functioning of the transmission line and for maximizing the effect on the plasma. This thesis gives all necessary tools for finding the proportion of the fundamental mode and all other modes present in passive components and at the output of the gyrotron as installed in the Tore Supra ECRH plant. This characterisation is based on obtaining amplitude and phase diagrams of the electric field on a plane transverse to the propagation axis. The most difficult part of obtaining these diagrams is measuring the phase which, despite the very short wavelength, is measured directly at low power levels. At high power levels the phase is numerically reconstructed from amplitude measurements for gyrotron characterisation. A complete theoretical study of the phase reconstruction code is given including its validation with theoretical diagrams. This study allows the realisation of a modal characterisation unit electromagnetic for measurement of radiated beams and usable in each part of the ECRH installation. At the end, the complete modal characterisation is given at low level for a mode converter and also at high level for the first series gyrotron installed at TORE SUPRA. (author)

  1. Global Simulation of Electromagnetic Ion Cyclotron Waves

    Science.gov (United States)

    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

  2. Cyclotron resonance in InAs/AlSb quantum wells in magnetic fields up to 45 T

    Energy Technology Data Exchange (ETDEWEB)

    Spirin, K. E., E-mail: spirink@ipmras.ru; Krishtopenko, S. S. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Sadofyev, Yu. G. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Drachenko, O. [Laboratoire National des Champs Magn’etiques Intenses (France); Helm, M. [Forschungszentrum Dresden–Rossendorf, Dresden High-Magnetic-Field Laboratory and Institute of Ion-Beam Physics and Materials Research (Germany); Teppe, F.; Knap, W. [GIS-TERALAB Universite Montpellier II, Laboratoire Charles Coulomb UMR CNRS 5221 (L2C) (France); Gavrilenko, V. I. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2015-12-15

    Electron cyclotron resonance in InAs/AlSb heterostructures with quantum wells of various widths in pulsed magnetic fields up to 45 T are investigated. Our experimental cyclotron energies are in satisfactory agreement with the results of theoretical calculations performed using the eight-band kp Hamiltonian. The shift of the cyclotron resonance (CR) line, which corresponds to the transition from the lowest Landau level to the low magnetic-field region, is found upon varying the electron concentration due to the negative persistent photoconductivity effect. It is shown that the observed shift of the CR lines is associated with the finite width of the density of states at the Landau levels.

  3. Cyclotron resonance of figure-of-eight orbits in a type-II Weyl semimetal

    Science.gov (United States)

    Koshino, Mikito

    2016-07-01

    We study the cyclotron resonance in the electron-hole joint Fermi surface of a type-II Weyl semimetal. In magnetic field, the electron and hole pockets touching at the Weyl node are hybridized to form quantized Landau levels corresponding to semiclassical 8-shaped orbits. We calculate the dynamical conductivities for the electric fields oscillating in x and y directions and find that the resonant frequencies in x and y differ by a factor of two, reflecting the figure-of-eight electron motion in real space. The peculiar anisotropy in the cyclotron resonance serves as a unique characteristic of the dumbbell-like Fermi surface.

  4. Nonlinear sub-cyclotron resonance as a formation mechanism for gaps in banded chorus

    CERN Document Server

    Fu, Xiangrong; Dong, Chuanfei; Gary, S Peter

    2015-01-01

    An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at $\\omega \\simeq 0.5\\Omega_e$, where $\\Omega_e$ is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near $0.3\\Omega_e$ and $0.6\\Omega_e$. Here we present a novel nonlinear mechanism for the formation of these gaps using Hamiltonian theory and test-particle simulations in a homogeneous, magnetized, collisionless plasma. We find that an oblique whistler wave with frequency at a fraction of the electron cyclotron frequency can resonate with electrons, leading to effective energy exchange between the wave and particles.

  5. Cyclotron resonance in InAs/GaSb heterostructure in inclined magnetic field

    CERN Document Server

    Greshnov, A A; Vasilev, Yu B; Suchalkin, S D; Meltser, B Y; Ivanov, S V; Kopev, P S

    2002-01-01

    The mechanism of splitting the cyclotron resonance line in the InAs/GaSb heterostructure in the inclined magnetic field is experimentally and theoretically studied. It is shown that the electrons and holes mixing in leads to the anticrossing Landau levels and consequently to the cyclotron resonance line splitting. Splitting in the case of the inclined magnetic field was not observed which is explained by damping the electrons and holes states mixing in on the account of originating the additional barrier for the electrons and holes by availability of the magnetic field longitudinal constituent

  6. Ion cyclotron waves at Titan

    Science.gov (United States)

    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.

  7. Superconducting cyclotrons at Michigan State University

    Science.gov (United States)

    Blosser, H. G.

    1987-04-01

    This paper describes the status of the three superconducting cyclotrons which are in operation or under construction at the National Superconducting Cyclotron Laboratory. The oldest of these, the K500, has been in operation since September 1982 supporting a national user program in heavy ion nuclear physics. A second large research cyclotron, the K800, is now nearing completion. This cyclotron will accelerate lighter heavy ions to 200 MeV/nuc and heavier particles up to energies given by 1200 Q2/ A MeV/nucleon. The magnet for this cyclotron came into operation in May 1984 and has performed smoothly and reliably in three extended operating periods. At present, K800 construction activity centers on fabrication and installation of the rf system, the extraction system, and the ECR injection line. The third NSCL superconducting cyclotron is a smaller 50 MeV deuteron cyclotron to be used for neutron therapy in the radiation oncology center of a major Detroit hospital (Harper Hospital). Design features of this small, application oriented, cyclotron are described in some detail.

  8. Theoretical and experimental study of cyclotronic waves in a fusion plasma; Etude theorique et experimentale des ondes cyclotroniques electroniques dans un plasma de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Vezard, D.

    1994-12-20

    This thesis presents a study concerning cyclotronic waves in a plasma. It starts with an illustration of the elementary interaction between electromagnetic waves and matter.It shows that electrons from tokamak absorbs waves at cyclotronic frequency. Cyclotronic waves are studied by solving the dispersion relation in plasma; it concerns polarisation, absorption, dispersion, extinction. Then, classical theories are reminded in order to speak about decoupled electrons and their interactions. Absorption and emission properties of cyclotronic waves by electrons from a queue are described. After that, cyclotronic waves propagation is studied taking into account resonance. The last part of this thesis is dedicated to the electronic distribution function that is made by a wave spectra at a inferior hybrid frequency. (TEC). 129 refs., 75 figs.

  9. Developing the smallest possible medical cyclotron

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Imagine a portable medical cyclotron operated in a conventional radioactive facility at a hospital. Imagine a nurse or technician switching it on and producing isotopes at the patient’s bedside. Sounds like science fiction? Think again.   CERN has teamed up with Spain’s national scientific research centre (CIEMAT) to develop an avant-garde cyclotron to be used for Positron Emission Tomography (PET). “We plan to make a cyclotron that doesn't need an insulated building or ‘vault’: a cyclotron small enough to fit inside a hospital lift,” explains Jose Manuel Perez, who is leading the CIEMAT/CERN collaboration. “It will be the smallest possible medical cyclotron for single patient dose production and will dramatically reduce costs for hospitals.” While PET technology has transformed imaging techniques, many of its medical benefits have remained confined to highly specialised hospitals. “Studies have foun...

  10. 3-Dimensional Simulations of Multipacting Effects in RF Cavities of CYCIAE-100 Cyclotron

    Institute of Scientific and Technical Information of China (English)

    WANG; Chuan; JI; Bin; LI; Peng-zhan; YIN; Zhi-guo; LEI; Yu; XING; Jian-sheng; ZHANG; Tian-jue

    2013-01-01

    Multipacting phenomena have been observed in various RF structures of accelerators.The multipacting appearing in high-Q RF cavities of cyclotrons,are the well known examples that how disturbing these phenomenon could be during commissioning.The seed electrons will impact the cavity surface,produce new electrons.Under certain conditions(material and geometry of the RF structure,

  11. Charge reversal Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Lobodin, Vladislav V; Savory, Joshua J; Kaiser, Nathan K; Dunk, Paul W; Marshall, Alan G

    2013-02-01

    We report the first charge reversal experiments performed by tandem-in-time rather than tandem-in-space MS/MS. Precursor odd-electron anions from fullerene C(60), and even-electron ions from 2,7-di-tert-butylfluorene-9-carboxylic acid and 3,3'-bicarbazole were converted into positive product ions ((-)CR(+)) inside the magnet of a Fourier transform ion cyclotron resonance mass spectrometer. Charge reversal was activated by irradiating precursor ions with high energy electrons or UV photons: the first reported use of those activation methods for charge reversal. We suggest that high energy electrons achieve charge reversal in one step as double electron transfer, whereas UV-activated (-)CR(+) takes place stepwise through two single electron transfers and formally corresponds to a neutralization-reionization ((-)NR(+)) experiment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kurashima, Satoshi, E-mail: kurashima.satoshi@jaea.go.jp; Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Yoshida, Ken-Ichi; Okumura, Susumu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    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.

  13. Polarization in cyclotron radiation in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Luidmila Semionova; Denis Leahy; Jorge Paez

    2010-01-01

    We revisit the problem of radiative transitions of electrons in the presence of a strong magnetic field.We derive fully relativistic cyclotron transition rates for an arbitrary magnetic field,for any orientation of electron spin and for any polarization of the emitted radiation.Also,we obtain the transition rates for any value of the initial electron's parallel momentum.For very strong magnetic fields,transitions to the ground state predominate.Transition rates summed over the electron's spin orientation and for unpolarized radiation are also obtained,which confirm previous results by Latal.Transition widths are calculated for different electron spin orientations and different polarizations of radiation.We obtain general expressions for transition rates that reduce to the results for the non-relativistic case and for unpolarized radiation.Additionally we get,for the non-relativistic approximation,the transition rates for any polarization of radiation.As an application,the first five emission lines are evaluated and compared to the X-ray emitting neutron star V0332+53,which has multiple observable cyclotron lines,taking into account gravitational redshift.The most probable polarization is ∈(2).

  14. The electrostatic ion-cyclotron instability-a two-dimensional potential relaxation instability

    DEFF Research Database (Denmark)

    Popa, G.; Schrittwieser, R.; Juul Rasmussen, Jens;

    1985-01-01

    An experimental investigation shows that the electrostatic ion-cyclotron instability, driven by an electron current to a positively biased collector, is accompanied by strong coherent two-dimensional fluctuations of the plasma potential in front of the collector. These results suggest that this i......An experimental investigation shows that the electrostatic ion-cyclotron instability, driven by an electron current to a positively biased collector, is accompanied by strong coherent two-dimensional fluctuations of the plasma potential in front of the collector. These results suggest...

  15. Injection and extraction for cyclotrons

    CERN Document Server

    Kleeven, W

    2006-01-01

    The main design goals for beam injection are explained and special problems related to a central region with internal ion source are considered. The principle of a PIG source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different ways of (axial) injection are briefly outlined. A proposal for a magnetostatic axial inflector is given. Different solutions for beam extraction are treated. These include the internal target, extraction by stripping, resonant extraction using a deflector and self-extraction. The different ways of creating a turn-separation are explained. The purpose of different types of extraction devices such as harmonic coils, deflectors and gradient corrector channels are outlined. Several illustrations are given in the form of photographs and drawings.

  16. Cyclotron resonance studies on InAs/GaSb heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Petchsingh, Cattleya

    2002-07-01

    Far-infrared cyclotron resonance is used to study the magneto-optical properties of semimetallic InAs/GaSb heterostructures. Spatially separated two-dimensional electron and hole gases coexist in this 'broken-gap' type-ll system due to charge transfer across the interfaces. Hybridisations of the overlapping electron and hole wavefunctions are investigated experimentally in samples of varying growth parameters. A self-consistent 8-band k{center_dot}p model is used to assist in the interpretation of experimental results. In samples subjected to varying magnetic field, hybridisations result in oscillations of cyclotron resonance mass, amplitude and linewidth, accompanied by transition splittings in the vicinity of Landau level anticrossings. Asymmetries introduced by InSb interface biasing enhance these effects. Comparison of samples with varying confinement energies (at specified magnetic field) shows effective mass enhancement greater than the standard nonparabolicity effect. The mass enhancement increases with hybridisation strength. A simple two-band minigap model gives good agreement with experimental results. Tilled field measurements show that hybridisation suppresses electron cyclotron resonance transitions. Increased resonance amplitudes at higher temperatures are therefore ascribed to reduced hybridisation strength. Strong evidence of Coulomb interactions between different single particle transitions shows the interactions increasing with temperature, leading to a single motion-averaged transition at sufficiently high temperature. High magnetic field measurements near the quantum limit show transition features generally consistent with electron-hole Landau level hybridisation. Multiple splittings in this field range (14-27T) are ascribed to spin splitting and subband coupling effects. Breaking of selection rules is suggested to be due to inherent band asymmetries in the samples. For narrow well samples, some transition features remain unexplained

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

    Energy Technology Data Exchange (ETDEWEB)

    Carbajal, L., E-mail: L.Carbajal-Gomez@warwick.ac.uk; Cook, J. W. S. [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Dendy, R. O. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, Oxfordshire (United Kingdom); Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Chapman, S. C. [Centre for Fusion, Space and Astrophysics, Department of Physics, The University of Warwick, Coventry CV4 7AL (United Kingdom); Department of Mathematics and Statistics, University of Tromsø, N-9037, Tromsø (Norway); Max Planck Institute for the Physics of Complex Systems, D-01187, Dresden (Germany)

    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.

  18. Method and apparatuses for ion cyclotron spectrometry

    Science.gov (United States)

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

    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.

  19. Shielding Design for a Medical Cyclotron

    Institute of Scientific and Technical Information of China (English)

    WANG; Feng; SONG; Guo-fang; GUAN; Feng-ping; LV; Yin-long; ZHANG; Xing-zhi

    2012-01-01

    <正>A 10 MeV 100 μA medical cyclotron is constructed at CIAE which is used in the production of FDG. The energy of the cyclotron can reach 14 MeV by adjusting the magnetic field and RF system parameters, and the shielding design is in accordance with the 14 MeV beam energy. In this shielding design only neutron is considered, and the neutron source is produced by proton

  20. Building 211 cyclotron characterization survey report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-30

    The Building 211 Cyclotron Characterization Survey includes an assessment of the radioactive and chemical inventory of materials stored within the facility; an evaluation of the relative distribution of accelerator-produced activation products within various cyclotron components and adjacent structures; measurement of the radiation fields throughout the facility; measurement and assessment of internal and external radioactive surface contamination on various equipment, facility structures, and air-handling systems; and an assessment of lead (Pb) paint and asbestos hazards within the facility.