WorldWideScience

Sample records for cyclotron instability

  1. Ion-cyclotron instability in magnetic mirrors

    International Nuclear Information System (INIS)

    Pearlstein, L.D.

    1987-01-01

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

  2. RELATIVISTIC CYCLOTRON INSTABILITY IN ANISOTROPIC PLASMAS

    Energy Technology Data Exchange (ETDEWEB)

    López, Rodrigo A.; Moya, Pablo S.; Muñoz, Víctor; Valdivia, J. Alejandro [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Navarro, Roberto E.; Araneda, Jaime A. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Viñas, Adolfo F., E-mail: rlopez186@gmail.com [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, MD 20771 (United States)

    2016-11-20

    A sufficiently large temperature anisotropy can sometimes drive various types of electromagnetic plasma micro-instabilities, which can play an important role in the dynamics of relativistic pair plasmas in space, astrophysics, and laboratory environments. Here, we provide a detailed description of the cyclotron instability of parallel propagating electromagnetic waves in relativistic pair plasmas on the basis of a relativistic anisotropic distribution function. Using plasma kinetic theory and particle-in-cell simulations, we study the influence of the relativistic temperature and the temperature anisotropy on the collective and noncollective modes of these plasmas. Growth rates and dispersion curves from the linear theory show a good agreement with simulations results.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  4. 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....

  5. 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....

  6. Nonlinear analysis of a relativistic beam-plasma cyclotron instability

    Science.gov (United States)

    Sprangle, P.; Vlahos, L.

    1986-01-01

    A self-consistent set of nonlinear and relativistic wave-particle equations are derived for a magnetized beam-plasma system interacting with electromagnetic cyclotron waves. In particular, the high-frequency cyclotron mode interacting with a streaming and gyrating electron beam within a background plasma is considered in some detail. This interaction mode may possibly find application as a high-power source of coherent short-wavelength radiation for laboratory devices. The background plasma, although passive, plays a central role in this mechanism by modifying the dielectric properties in which the magnetized electron beam propagates. For a particular choice of the transverse beam velocity (i.e., the speed of light divided by the relativistic mass factor), the interaction frequency equals the nonrelativistic electron cyclotron frequency times the relativistic mass factor. For this choice of transverse beam velocity the detrimental effects of a longitudinal beam velocity spread is virtually removed. Power conversion efficiencies in excess of 18 percent are both analytically calculated and obtained through numerical simulations of the wave-particle equations. The quality of the electron beam, degree of energy and pitch angle spread, and its effect on the beam-plasma cyclotron instability is studied.

  7. The effect of plasma drift on the electromagnetic cyclotron instability

    International Nuclear Information System (INIS)

    Kulkarni, V.H.; Rycroft, M.J.

    1979-01-01

    It is shown that the drift of plasma across a homogeneous magnetic field causes the generation of a wave electric field which, for waves propagating along the magnetic field in the whistler mode, is in the direction of the magnetic field. This leads to Landau damping of the wave field by the background electron distribution, simultaneously with amplification via the electromagnetic cyclotron instability. The drift velocity of the plasma for zero net growth of a whistler mode signal is calculated. It is suggested that such a process occurs in the equatorial region of the magnetosphere during a geomagnetic storm and accounts for the missing band of emissions at half the equatorial gyrofrequency. (Auth.)

  8. Evolution of the axial electron cyclotron maser instability, with applications to solar microwave spikes

    Science.gov (United States)

    Vlahos, Loukas; Sprangle, Phillip

    1987-01-01

    The nonlinear evolution of cyclotron radiation from streaming and gyrating electrons in an external magnetic field is analyzed. The nonlinear dynamics of both the fields and the particles are treated fully relativistically and self-consistently. The model includes a background plasma and electrostatic effects. The analytical and numerical results show that a substantial portion of the beam particle energy can be converted to electromagnetic wave energy at frequencies far above the electron cyclotron frequency. In general, the excited radiation can propagate parallel to the magnetic field and, hence, escape gyrothermal absorption at higher cyclotron harmonics. The high-frequency Doppler-shifted cyclotron instability can have saturation efficiencies far higher than those associated with well-known instabilities of the electron cyclotron maser type. Although the analysis is general, the possibility of using this model to explain the intense radio emission observed from the sun is explored in detail.

  9. Evolution of the axial electron cyclotron maser instability, with applications to solar microwave spikes

    International Nuclear Information System (INIS)

    Vlahos, L.; Sprangle, P.

    1987-01-01

    The nonlinear evolution of cyclotron radiation from streaming and gyrating electrons in an external magnetic field is analyzed. The nonlinear dynamics of both the fields and the particles are treated fully relativistically and self-consistently. The model includes a background plasma and electrostatic effects. The analytical and numerical results show that a substantial portion of the beam particle energy can be converted to electromagnetic wave energy at frequencies far above the electron cyclotron frequency. In general, the excited radiation can propagate parallel to the magnetic field and, hence, escape gyrothermal absorption at higher cyclotron harmonics. The high-frequency Doppler-shifted cyclotron instability can have saturation efficiencies far higher than those associated with well-known instabilities of the electron cyclotron maser type. Although the analysis is general, the possibility of using this model to explain the intense radio emission observed from the sun is explored in detail. 31 references

  10. Electron cyclotron waves, transport and instabilities in hot plasmas

    International Nuclear Information System (INIS)

    Westerhof, E.

    1987-01-01

    A number of topics relevant to the magnetic confinement approach to the thermonuclear fusion is addressed. The absorption and emission of electron cyclotron waves in a thermal plasma with a small population of supra-thermal, streaming electrons is examined and the properties of electron cyclotron waves in a plasma with a pure loss-cone distribution are studied. A report is given on the 1-D transport code simulations that were performed to assist the interpretation of the electron cyclotron heating experiments on the TFR tokamak. Transport code simulations of sawteeth discharges in the T-10 tokamak are discussed in order to compare the predictions of different models for the sawtooth oscillations with the experimental findings. 149 refs.; 69 figs.; 7 tabs

  11. 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.

  12. Theory of the current-driven ion cyclotron instability in the bottomside ionosphere

    International Nuclear Information System (INIS)

    Satyanarayana, P.; Chaturvedi, P.K.; Keskinen, M.J.; Huba, J.D.; Ossakow, S.L.

    1985-01-01

    A theory of the current-driven electrostatic ion cyclotron (EIC) instability in the collisional bottomside ionosphere is presented. It is found that electron collisions are destabilizing and are crucial for the excitation of the EIC instability in the collisional bottomside ionosphere. Furthermore, the growth rates of the ion cyclotron instability in the bottomside ionosphere maximize for k/sub perpendicular/ rho/sub i/> or =1, where 2π/k/sub perpendicular/ is the mode scale size perpendicular to the magnetic field and rho/sub i/ the ion gyroradius. Realistic plasma density and temperature profiles typical of the high-latitude ionosphere are used to compute the altitude dependence of the linear growth rate of the maximally growing modes and critical drift velocity of the EIC instability. The maximally growing modes correspond to observed tens of meter size irregularities, and the threshold drift velocity required for the excitation of EIC instability is lower for heavier ions (NO + , O + ) than that for the lighter ions (H + ). Dupree's resonance-broadening theory is used to estimate nonlinear saturated amplitudes for the ion cyclotron instability in the high-latitude ionosphere. Comparison with experimental observations is also made. It is conjectured that the EIC instability in the bottomside ionosphere could be a source of transversely accelerated heavier ions and energetic heavy-ion conic distributions at higher altitudes

  13. Ion cyclotron instability saturation and turbulent plasma heating in the presence of ions moving across the magnetic field

    International Nuclear Information System (INIS)

    Mikhajlenko, V.S.; Stepanov, K.N.

    1981-01-01

    Ion cyclotron instability saturation is considered in terms of the turbulence theory when there is a beam of heavy ions with large thermal longitudinal velocity spread. The instability excitation is due to a cyclotron interaction with ions of the beam under the anomalous Doppler effect. The instability is shown to be saturated due to an induced plasma ion scattering of ion cyclotron waves when the beam ion charge number Zsub(b) is approximately 1. Decay processes, wave scattering by virtual wave polarization clouds and resonance broadening due to random walk of plasma ions in turbulent instability fields appear to be unimportant. For Zsub(b)>>1 the induced wave scattering by the beam ions is the main process determining the nonlinear stage of the instability. Estimates are given for the oscillation energy density in the instability saturation state and for the turbulent heating rate of plasma and beam ions [ru

  14. Electron cyclotron maser instability in the solar corona: The role of superthermal tails

    International Nuclear Information System (INIS)

    Vlahos, L.; Sharma, R.R.

    1985-01-01

    The effect of a superthermal component of electrons on the loss-cone--driven electron cyclotron maser instability is analyzed. We found that for a supertheral tail with temperature approx.10 keV (i) the first harmonic (X- and O-mode) is suppressed for n/sub t//n/sub r/roughly-equal1 (n/sub t/ and n/sub r/ are the densities of superthermal tail and loss-cone electrons) and (ii) the second harmonic (X- and O-modes) is suppressed for n/sub t//n/sub r/ -1 . We present a qualitative discussion on the formation of superthermal taisl and suggest that superthermal tails play an important role on the observed or available power, at microwave frequencies, from the electron cyclotron maser instability in the solar corona

  15. Electron cyclotron maser instability in the solar corona - The role of superthermal tails

    Science.gov (United States)

    Vlahos, L.; Sharma, R. R.

    1985-01-01

    The effect of a superthermal component of electrons on the loss-cone-driven electron cyclotron maser instability is analyzed. It is found that for a superthermal tail with temperature about 10 KeV, the first harmonic (X- and O-mode) is suppressed for n(t)/n(r) of about 1 (n/t/ and n/r/ are the densities of superthermal tail and loss-cone electrons) and the second harmonic (X- and O-modes) is suppressed for n(t)/n(r) less than about 0.1. A qualitative discussion on the formation of superthermal tails is presented and it is suggested that superthermal tails play an important role on the observed or available power, at microwave frequencies, from the electron cyclotron maser instability in the solar corona.

  16. Excitation of electromagnetic proton cyclotron instability by parallel electric field in the equatorial magnetosphere

    International Nuclear Information System (INIS)

    Dixit, S.K.; Azif, Z.A.; Gwal, A.K.

    1994-01-01

    The characteristics of the growth rate of electromagnetic ion cyclotron (EMIC) instability is investigated in a mixture of cold species of ions and warm proton in the presence of weak parallel static electric field. An attempt has been made to explain the excitation of EMIC waves through linear wave-particle (W-P) interaction in the equatorial magnetospheric region. The proton cyclotron instability is modified in presence of weak parallel electric field and the growth rate is computed for equatorial magnetospheric plasma parameters. The results of theoretical investigations of the growth rate are used to explain the excitation mechanism of extremely low frequency/very low frequency (ELF/VLF) waves as observed by satellites. (author). 29 refs., 4 figs

  17. Warm ion effects on kinetic drift cyclotron loss cone instabilities

    International Nuclear Information System (INIS)

    Guo Shichong; Shen Jiewu; Cai Shidong

    1988-01-01

    The effects of adding warm plasmas on the kinetic DCLC mode in high β loss cone plasmas are investigated in detail. It is found that when the fluid DCLC mode is stabilized by a small amount of warm plasma, the kinetic excitation still remains due to two different mechanisms, namely, (1) magnetic drift resonance dissipation excites the negative energy wave; (2) a new type of positive energy wave can become unstable as the resonance condition is met. Comparing with fluid approximation theory, more warm plasmas are needed to suppress the kinetic DCLC instabilities

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  19. Instability of surface electron cyclotron TM-modes influenced by non-monochromatic alternating electric field

    International Nuclear Information System (INIS)

    Girka, I. O.; Girka, V. O.; Sydora, R. D.; Thumm, M.

    2016-01-01

    The influence of non-monochromaticity of an external alternating electric field on excitation of TM eigenmodes at harmonics of the electron cyclotron frequency is considered here. These TM-modes propagate along the plasma interface in a metal waveguide. An external static constant magnetic field is oriented perpendicularly to the plasma interface. The problem is solved theoretically using the kinetic Vlasov-Boltzmann equation for description of plasma particles motion and the Maxwell equations for description of the electromagnetic mode fields. The external alternating electric field is supposed to be a superposition of two waves, whose amplitudes are different and their frequencies correlate as 2:1. An infinite set of equations for electric field harmonics of these modes is derived with the aid of nonlinear boundary conditions. This set is solved using the wave packet approach consisting of the main harmonic frequency and two nearest satellite temporal harmonics. Analytical studies of the obtained set of equations allow one to find two different regimes of parametric instability, namely, enhancement and suppression of the instability. Numerical analysis of the instability is carried out for the three first electron cyclotron harmonics.

  20. Kinetic instability of electrostatic ion cyclotron waves in inter-penetrating plasmas

    Science.gov (United States)

    Bashir, M. F.; Ilie, R.; Murtaza, G.

    2018-05-01

    The Electrostatic Ion Cyclotron (EIC) instability that includes the effect of wave-particle interaction is studied owing to the free energy source through the flowing velocity of the inter-penetrating plasmas. It is shown that the origin of this current-less instability is different from the classical current driven EIC instability. The threshold conditions applicable to a wide range of plasma parameters and the estimate of the growth rate are determined as a function of the normalized flowing velocity ( u0/vt f e ), the temperature ( Tf/Ts ) and the density ratios ( nf 0/ns 0 ) of flowing component to static one. The EIC instability is driven by either flowing electrons or flowing ions, depending upon the different Doppler shifted frequency domains. It is found that the growth rate for electron-driven instability is higher than the ion-driven one. However, in both cases, the denser (hotter) is the flowing plasma, the lesser (greater) is the growth rate. The possible applications related to the terrestrial solar plasma environment are also discussed.

  1. Experimental study of an ion cyclotron instability in a magnetic well confined plasma

    International Nuclear Information System (INIS)

    Brossier, P.

    1969-01-01

    This report is a contribution to the study of microinstabilities in macroscopically stable plasmas, in the low-β limit. Ion cyclotron instabilities, with k || = 0, have been numerically studied in detail; the computation of the density thresholds and growth rates of the different harmonics showed the relative role played by the following energy sources: density gradient, perpendicular distribution function and cold plasma component. This theoretical model has been compared with the results of a detailed study (density thresholds, wave structure, frequency spectrum, wavelengths, growth rate, amplitude of the electric field) of the instability observed in the DECA II device. This comparison gave a good agreement which shows the destabilising role played by the cold plasma component on a hot plasma with a loss cone distribution function. (author) [fr

  2. Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction for fustion alphas in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Arunasalam, V.

    1995-07-01

    It is shown here that the marginally mirror-trapped fraction of the newly-born fusion alpha particles in the deuterium-tritium (DT) reaction dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for the fast Alfven waves propagating near the harmonics of the alpha particle cyclotron frequency {omega}{sub c{alpha}}. This can explain both the experimentally observed time behavior and the spatially localized origin of the fusion product ion cyclotron emission (ICE) in TFTR at frequencies {omega} {approx} m{omega}{sub c{alpha}}.

  3. Two-stream cyclotron radiative instabilities due to the marginally mirror-trapped fraction for fustion alphas in tokamaks

    International Nuclear Information System (INIS)

    Arunasalam, V.

    1995-07-01

    It is shown here that the marginally mirror-trapped fraction of the newly-born fusion alpha particles in the deuterium-tritium (DT) reaction dominated tokamak plasmas can induce a two-stream cyclotron radiative instability for the fast Alfven waves propagating near the harmonics of the alpha particle cyclotron frequency ω cα . This can explain both the experimentally observed time behavior and the spatially localized origin of the fusion product ion cyclotron emission (ICE) in TFTR at frequencies ω ∼ mω cα

  4. Experimental test of the electromagnetic ion cyclotron instability within the earth's magnetosphere

    International Nuclear Information System (INIS)

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

    1980-01-01

    The ATS-6 geostationary satellite has observed many examples of propagating, electromagnetic Alfven/ion cyclotron waves in both plasma particle and magnetic field data. These waves have been viewed predominantly near the afternoon and dusk regions of the earth's magnetosphere with normalized frequencies (ω/Ω/sub H/ + ) ranging between 0.05 and 0.5. Viewed from an average geomagnetic latitude of +10 0 , the waves have only been observed to propagate northward, suggesting that they are generated within the equatorial or minimum BETA regions. Two wave events have been chosen for detailed analysis. Both events appeared coincidentally with the encounter of cool plasma populations (5 eV) which joined the hot populations already present (10--40 keV). These coincidences suggest the popular, yet largely untested, electromagnetic ion cyclotron instability as the wave generation mechanism. As a test of this hypothesis, ion cyclotron amplification profiles are obtained by evaluating the linear growth rate integrals under the measured, anisotropic hot ion distributions. The measured frequencies for both of the chosen events are in good agreement with the quite restricted values which correspond to the peaks of the amplification profiles. As a result of magnetic field inhomogeneities, the interactions remain within the linear regime

  5. PARTICLE-IN-CELL SIMULATIONS OF CONTINUOUSLY DRIVEN MIRROR AND ION CYCLOTRON INSTABILITIES IN HIGH BETA ASTROPHYSICAL AND HELIOSPHERIC PLASMAS

    International Nuclear Information System (INIS)

    Riquelme, Mario A.; Quataert, Eliot; Verscharen, Daniel

    2015-01-01

    We use particle-in-cell simulations to study the nonlinear evolution of ion velocity space instabilities in an idealized problem in which a background velocity shear continuously amplifies the magnetic field. We simulate the astrophysically relevant regime where the shear timescale is long compared to the ion cyclotron period, and the plasma beta is β ∼ 1-100. The background field amplification in our calculation is meant to mimic processes such as turbulent fluctuations or MHD-scale instabilities. The field amplification continuously drives a pressure anisotropy with p > p ∥ and the plasma becomes unstable to the mirror and ion cyclotron instabilities. In all cases, the nonlinear state is dominated by the mirror instability, not the ion cyclotron instability, and the plasma pressure anisotropy saturates near the threshold for the linear mirror instability. The magnetic field fluctuations initially undergo exponential growth but saturate in a secular phase in which the fluctuations grow on the same timescale as the background magnetic field (with δB ∼ 0.3 (B) in the secular phase). At early times, the ion magnetic moment is well-conserved but once the fluctuation amplitudes exceed δB ∼ 0.1 (B), the magnetic moment is no longer conserved but instead changes on a timescale comparable to that of the mean magnetic field. We discuss the implications of our results for low-collisionality astrophysical plasmas, including the near-Earth solar wind and low-luminosity accretion disks around black holes

  6. Ion cyclotron emission due to collective instability of fusion products and beam ions in TFTR and JET

    International Nuclear Information System (INIS)

    Dendy, R.O.; McClements, K.G.; Lashmore Davies, C.N.; Cottrell, G.A.; Majeski, R.; Cauffman, S.

    1995-01-01

    Ion cyclotron emission (ICE) has been observed from neutral beam heated TFTR and JET tritium experiments at sequential cyclotron harmonics of both fusion products and beam ions. The emission originates from the outer midplane plasma, where fusion products and beam ions are likely to have a drifting ring-type velocity-space distribution that is anisotropic and sharply peaked. Fusion product driven ICE can be attributed to the magnetoacoustic cyclotron instability, which involves the excitation of obliquely propagating waves on the fast Alfven/ion Bernstein branch at cyclotron harmonics of the fusion products. Differences between ICE observations in JET and TFTR appear to reflect the sensitivity of the instability growth rate to the ratio υ birth /c A , where υ birth is the fusion product birth speed and c A is the local Alfven speed: for fusion products in the outer midplane edge of TFTR supershots, υ birth A ; for alpha particles in the outer midplane edge of JET, the opposite inequality applies. If sub-Alfvenic fusion products are isotropic or have undergone even a moderate degree of thermalization, the magnetoacoustic instability cannot occur. In contrast, the super-Alfvenic alpha particles that are present in the outer midplane of JET can drive the magnetoacoustic cyclotron instability even if they are isotropic or have a relatively broad distribution of speeds. These conclusions may account for the observation that fusion product driven ICE in JET persists for longer than fusion product driven ICE in TFTR. A separate mechanism is proposed for the excitation of beam driven ICE in TFTR: electrostatic ion cyclotron harmonic waves, supported by strongly sub-Alfvenic beam ions, can be destabilized by a low concentration of such ions with a very anrrow spread of velocities in the parallel direction. 25 refs, 14 figs

  7. Quasilinear analysis of loss-cone driven weakly relativistic electron cyclotron maser instability

    International Nuclear Information System (INIS)

    Ziebell, L.F.; Yoon, P.H.

    1995-01-01

    This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability. Two electron populations are assumed: a low-temperature background component and a more energetic loss-cone population. The dispersion relation is valid for any ratio of the energetic to cold populations, and includes thermal and relativistic effects. The quasilinear analysis is based upon an efficient kinetic moment method, in which various moment equations are derived from the particle kinetic equation. A model time-dependent loss-cone electron distribution function is assumed, which allows one to evaluate the instantaneous linear growth rate as well as the moment kinetic equations. These moment equations along with the wave kinetic equation form a fully self-consistent set of equations which governs the evolution of the particles as well as unstable waves. This set of equations is solved with physical parameters typical of the earth's auroral zone plasma. copyright 1995 American Institute of Physics

  8. Influence of non-bi-maxwellian distribution function of solar wind protons on the ion cyclotron instability

    International Nuclear Information System (INIS)

    Leubner, M.P.

    1978-01-01

    Satellite measurements of the thermal anisotropy of solar wind protons have shown that the particle velocity distributions at 1 AU are not adequately described by a bi-Maxwellian distribution function. On the other hand, the stability criteria derived from a bi-Maxwellian distribution require T/sub perpendicular/>T/sub parallel/, which is, however, hardly ever observed. A modified axisymmetric distribution function for solar wind protons is used here to calculate the stability and growth rate of the iom cyclotron instability in a warm slow speed solar plasma at 1 AU. Cyclotron wave growth is found also in the case t/sub parallel/>T/sub perpendicular/

  9. Ion cyclotron emission due to collective instability of fusion products and beam ions in TFTR and JET

    International Nuclear Information System (INIS)

    Dendy, R.O.; Clements, K.G.; Lashmore-Davies, C.N.; Cottrell, G.A.; Majeski, R.; Cauffman, S.

    1995-06-01

    Ion cyclotron emission (ICE) has been observed from neutral beam-heated TFTR and JET tritium experiments at sequential cyclotron harmonics of both fusion products and beam ions. The emission originates from the outer mid-plane plasma, where fusion products and beam ions are likely to have a drifting ring-type velocity-space distribution which is anisotropic and sharply peaked. Fusion product-driven ICE in both TFTR and JET can be attributed to the magnetoacoustic cyclotron instability, which involves the excitation of obliquely propagating waves on the fast Alfven/ion Bernstein branch at cyclotron harmonics of the fusion products. Differences between ICE observations in JET and TFTR appear to reflect the sensitivity of the instability growth rate to the ratio υ birth /c A , where υ birth is the fusion product birth speed and c A is the local Alfven speed:for fusion products in the outer midplane edge of TFTR, υ birth A ; for alpha-particles in the outer midplane edge of JET, the opposite inequality applies. If sub-Alfvenic fusion products are isotropic or have undergone even a moderate degree of thermalization, the magnetoacoustic instability cannot occur. In contrast, the super-Alfvenic alpha-particles which are present in the outer mid-plane of JET can drive the magnetoacoustic cyclotron instability even if they are isotropic or have a relatively broad distribution of speeds. These conclusions may account for the observation that fusion product-driven ICE in JET persists for longer than fusion product-driven ICE in TFTR. (Author)

  10. Inhibition of the electron cyclotron maser instability in the dense magnetosphere of a hot Jupiter

    Science.gov (United States)

    Daley-Yates, S.; Stevens, I. R.

    2018-06-01

    Hot Jupiter (HJ) type exoplanets are expected to produce strong radio emission in the MHz range via the Electron Cyclotron Maser Instability (ECMI). To date, no repeatable detections have been made. To explain the absence of observational results, we conduct 3D adaptive mess refinement (AMR) magnetohydrodynamic (MHD) simulations of the magnetic interactions between a solar type star and HJ using the publicly available code PLUTO. The results are used to calculate the efficiency of the ECMI at producing detectable radio emission from the planets magnetosphere. We also calculate the frequency of the ECMI emission, providing an upper and lower bounds, placing it at the limits of detectability due to Earth's ionospheric cutoff of ˜10 MHz. The incident kinetic and magnetic power available to the ECMI is also determined and a flux of 0.075 mJy for an observer at 10 pc is calculated. The magnetosphere is also characterized and an analysis of the bow shock which forms upstream of the planet is conducted. This shock corresponds to the thin shell model for a colliding wind system. A result consistent with a colliding wind system. The simulation results show that the ECMI process is completely inhibited by the planets expanding atmosphere, due to absorption of UV radiation form the host star. The density, velocity, temperature and magnetic field of the planetary wind are found to result in a magnetosphere where the plasma frequency is raised above that due to the ECMI process making the planet undetectable at radio MHz frequencies.

  11. Dynamic shear stabilization of hydromagnetic instabilities in low-beta plasma column by a frequency near the ion cyclotron frequency

    International Nuclear Information System (INIS)

    Minami, Kazuo; Sato, Kazunori.

    1978-09-01

    The dynamic shear stabilization of the hydromagnetic instability in low-beta plasmas by an axial RF current whose frequency is not much smaller than the ion cyclotron frequency ωsub(ci) is analyzed in some detail. We adopt the simple model of a uniform plasma column with infinite conductivity. Attention is limited to the case of the m = 1 kink mode with long wave lengths. The Mathieu equation, in which the effect of the ion cyclotron motion is taken into account, is derived. It is shown that the dynamic shear stabilization is still effective, even if the frequency of the applied RF current is of the order of ωsub(ci), which is considerably higher than the frequencies believed to be available in the previous analyses. (author)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    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

  13. Electron cyclotron instabilities of finite pressure inhomogeneous plasma in crossed fields

    International Nuclear Information System (INIS)

    Kirochkin, Yu.A.; Pokroev, A.G.; Stepanov, K.N.

    1979-01-01

    The stability of inhomogeneous plasma sheet with β<=1 in crossed electric and magnetic fields is investigated. The differential equation describing potential oscillations is obtained. Using the local approximation the sheet is shown to be unstable against the excitation of short wavelength electron cyclotron oscillations. The validity criterion of this method for a given type of waves is derived

  14. Ion cyclotron instability at Io: Hybrid simulation results compared to in situ observations

    Czech Academy of Sciences Publication Activity Database

    Šebek, Ondřej; Trávníček, Pavel M.; Walker, R. J.; Hellinger, Petr

    2016-01-01

    Roč. 121, č. 8 (2016), s. 7514-7534 ISSN 2169-9380 Institutional support: RVO:68378289 Keywords : Io * ionization processes * ion cyclotron waves Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA022477/abstract

  15. Ion cyclotron instability at Io: Hybrid simulation results compared to in situ observations

    Czech Academy of Sciences Publication Activity Database

    Šebek, Ondřej; Trávníček, Pavel M.; Walker, R.; Hellinger, Petr

    2016-01-01

    Roč. 121, č. 8 (2016), s. 7514-7534 ISSN 2169-9380 Institutional support: RVO:67985815 Keywords : Io * ionization processes * ion cyclotron waves Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BN - Astronomy, Celestial Mechanics, Astrophysics (UFA-U) Impact factor: 2.733, year: 2016

  16. Characteristics of the resonant instability of surface electrostatic-ion-cyclotron waves in a semi-bounded warm magnetized dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Woo-Pyo [Department of Electronics Engineering, Catholic University of Daegu, Hayang, 38430 (Korea, Republic of); Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 15588 (Korea, Republic of); Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180-3590 (United States)

    2016-03-11

    The influence of magnetic field and dust rotation on the resonant instability of surface electrostatic-ion-cyclotron wave is kinetically investigated in a semi-bounded warm magnetized dusty plasma. The dispersion relation and the temporal growth rate of the surface electrostatic-ion-cyclotron wave are derived by the specular-reflection boundary condition including the magnetic field and dust rotation effects. It is found that the instability domain decreases with an increase of the rotation frequency of elongated dust grain. It is also found that the dependence of the propagation wave number on the temporal growth rate is more significant for small ion cyclotron frequencies. In addition, it is shown that the scaled growth rate increases with an increase of the strength of magnetic field. The variation of the domain and magnitude of temporal growth rate due to the change of plasma parameters is also discussed. - Highlights: • The resonant instability of surface electrostatic-ion-cyclotron wave is investigated in a semi-bounded magnetized dusty plasma. • The dispersion relation and the temporal growth rate are derived by the specular-reflection condition. • The influence of magnetic field and dust rotation on the resonant instability is discussed.

  17. How expanded ionospheres of Hot Jupiters can prevent escape of radio emission generated by the cyclotron maser instability

    Science.gov (United States)

    Weber, C.; Lammer, H.; Shaikhislamov, I. F.; Chadney, J. M.; Khodachenko, M. L.; Grießmeier, J.-M.; Rucker, H. O.; Vocks, C.; Macher, W.; Odert, P.; Kislyakova, K. G.

    2017-08-01

    We present a study of plasma conditions in the atmospheres of the Hot Jupiters HD 209458b and HD 189733b and for an HD 209458b like planet at orbit locations between 0.2 and 1 au around a Sun-like star. We discuss how these conditions influence the radio emission we expect from their magnetospheres. We find that the environmental conditions are such that the cyclotron maser instability (CMI), the process responsible for the generation of radio waves at magnetic planets in the Solar system, most likely will not operate at Hot Jupiters. Hydrodynamically expanding atmospheres possess extended ionospheres whose plasma densities within the magnetosphere are so large that the plasma frequency is much higher than the cyclotron frequency, which contradicts the condition for the production of radio emission and prevents the escape of radio waves from close-in exoplanets at distances produce radio emission. However, even if the CMI could operate, the extended ionospheres of Hot Jupiters are too dense to allow the radio emission to escape from the planets.

  18. Influence of energy and axial momentum spreads on the cyclotron maser instability in intense hollow electron beams

    International Nuclear Information System (INIS)

    Uhm, H.S.; Davidson, R.C.

    1979-01-01

    The influence of energy and axial momentum spreads on the cyclotron maser instability in an intense hollow electron beam propagating parallel to a uniform axial magnetic field B 0 e/sub z/ is investigated. The stability analysis is carried out within the framework of the linearized Vlasov--Maxwell equations. It is assumed that ν/gamma-circumflexvery-much-less-than1, where ν is Budker's parameter and gamma-circumflexmc 2 is the characteristic electron energy. Stability properties are investigated for the choice of electron distribution function in which all electrons have a step-function distribution in energy (H=γmc 2 ) and a step-function distribution in axial momentum (p/sub z/). The instability growth rate is calculated including the important stabilizing influence of energy spread (epsilon=Δγ) and axial momentum spread (Δ=Δp/sub z/). It is shown that a modest energy spread (epsilonapprox. = a few percent) is sufficient to stabilize perturbations with high magnetic harmonic number (s> or =2). Moreover, a relatively small axial momentum spread (Δ/mcapprox. =0.1) can easily stabilize perturbations with axial wavenumber satisfying vertical-barkc/ω/sub c/vertical-bar> or approx. =0.2, for typical beam parameters of experimental interest

  19. Cyclotron waves in plasma

    International Nuclear Information System (INIS)

    Lominadse, D.G.

    1975-01-01

    The book deals with fundamental physical concepts of the theory of cyclotron waves and cyclotron instabilities conditioned by the presence in plasma of direct or alternating electric currents passing in it perpendicularily to a magnetic field. A great variety of problems is considered connected with the linear theory of cyclotron oscillations in equilibrium and electron plasma of metals and semiconductors. Parametric excitations of electron cyclotron oscillations of plasma in an alternating electric field are studied. Particular attention is paid to the investigation of plasma turbulence arising as a result of development of cyclotron instabilities. Experimental data are discussed and compared with theoretical results

  20. Oblique propagating electromagnetic ion - Cyclotron instability with A.C. field in outer magnetosphere

    Science.gov (United States)

    Pandey, R. S.; Singh, Vikrant; Rani, Anju; Varughese, George; Singh, K. M.

    2018-05-01

    In the present paper Oblique propagating electromagnetic ion-cyclotron wave has been analyzed for anisotropic multi ion plasma (H+, He+, O+ ions) in earth magnetosphere for the Dione shell of L=7 i.e., the outer radiation belt of the magnetosphere for Loss-cone distribution function with a spectral index j in the presence of A.C. electric field. Detail for particle trajectories and dispersion relation has been derived by using the method of characteristic solution on the basis of wave particle interaction and transformation of energy. Results for the growth rate have been calculated numerically for various parameters and have been compared for different ions present in magnetosphere. It has been found that for studying the wave over wider spectrum, anisotropy for different values of j should be taken. The effect of frequency of A.C. electric field and angle which propagation vector make with magnetic field, on growth rate has been explained.

  1. Alfven-ion-cyclotron instability in the central cell of TMX

    International Nuclear Information System (INIS)

    Watson, D.C.; Baldwin, D.E.

    1977-01-01

    The central cell of TMX may require hot-ion injection. The resulting velocity-space anisotropy together with the length of the central homogeneous region raise the possibility of convective AIC instability. In this report we demonstrate that the Rosenbluth criterion of less than a thousand-fold amplitude amplification per pass can be satisfied by ion distributions which nevertheless have sufficient anisotropy to be confined within the central cell

  2. Effect of ion cyclotron acceleration on frequency chirping beam-driven instabilities in NSTX

    International Nuclear Information System (INIS)

    Ruskov, E.; Heidbrink, W.W.; Fredrickson, E.D.; Darrow, D.; Medley, S.; Gorelenkov, N.

    2006-01-01

    The fast-ion distribution function in the National Spherical Torus Experiment (NSTX) is modified from shot to shot while keeping the total injected power at ∼2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including TAE modes, 50-100∼kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (∼3 MW) harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the effective collision frequency. Steady-frequency TAE modes excited early in the discharge are affected by the HHFW heating but there is no evidence that the chirping of 20-100 kHz modes is suppressed. (author)

  3. Effect of Ion Cyclotron Acceleration on Frequency Chirping Beam-Driven Instabilities in NSTX

    International Nuclear Information System (INIS)

    Ruskov, E.; Heidbrink, W.W.; Fredrickson, E.D.; Darrow, D.; Medley, S.; Gorelenkov, N.

    2006-01-01

    The fast-ion distribution function in the National Spherical Torus Experiment (NSTX) is modified from shot to shot while keeping the total injected power at ∼2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including TAE modes, 50-100∼kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (∼3 MW) harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the effective collision frequency. Steady-frequency TAE modes excited early in the discharge are affected by the HHFW heating but there is no evidence that the chirping of 20-100 kHz modes is suppressed. (author)

  4. 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

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

    Science.gov (United States)

    Treumann, Rudolf A.; Baumjohann, Wolfgang

    2017-08-01

    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 of particular

  6. 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

  7. Two-stream instabilities from the lower-hybrid frequency to the electron cyclotron frequency: application to the front of quasi-perpendicular shocks

    Directory of Open Access Journals (Sweden)

    L. Muschietti

    2017-09-01

    Full Text Available Quasi-perpendicular supercritical shocks are characterized by the presence of a magnetic foot due to the accumulation of a fraction of the incoming ions that is reflected by the shock front. There, three different plasma populations coexist (incoming ion core, reflected ion beam, electrons and can excite various two-stream instabilities (TSIs owing to their relative drifts. These instabilities represent local sources of turbulence with a wide frequency range extending from the lower hybrid to the electron cyclotron. Their linear features are analyzed by means of both a dispersion study and numerical PIC simulations. Three main types of TSI and correspondingly excited waves are identified: i. Oblique whistlers due to the (so-called fast relative drift between reflected ions/electrons; the waves propagate toward upstream away from the shock front at a strongly oblique angle (θ ∼ 50° to the ambient magnetic field Bo, have frequencies a few times the lower hybrid, and have wavelengths a fraction of the ion inertia length c∕ωpi. ii. Quasi-perpendicular whistlers due to the (so-called slow relative drift between incoming ions/electrons; the waves propagate toward the shock ramp at an angle θ a few degrees off 90°, have frequencies around the lower hybrid, and have wavelengths several times the electron inertia length c∕ωpe. iii. Extended Bernstein waves which also propagate in the quasi-perpendicular domain, yet are due to the (so-called fast relative drift between reflected ions/electrons; the instability is an extension of the electron cyclotron drift instability (normally strictly perpendicular and electrostatic and produces waves with a magnetic component which have frequencies close to the electron cyclotron as well as wavelengths close to the electron gyroradius and which propagate toward upstream. Present results are compared with previous works in order to stress some features not previously analyzed and to define a more

  8. A parametric investigation on the cyclotron maser instability driven by ring-beam electrons with intrinsic Alfvén waves

    Science.gov (United States)

    Tong, Zi-Jin; Wang, Chuan-Bing; Zhang, Pei-Jin; Liu, Jin

    2017-05-01

    The electron-cyclotron maser is a process that generates the intense and coherent radio emission in the plasma. In this paper, we present a comprehensive parametric investigation on the electron-cyclotron-maser instability driven by non-thermal ring-beam electrons with intrinsic Alfvén waves, which pervade the solar atmosphere and interplanetary space. It is found that both forward propagating and backward propagating waves can be excited in the fast ordinary (O) and extraordinary (X) electromagnetic modes. The growth rates of X1 mode are almost always weakened by Alfvén waves. The average pitch-angle ϕ 0 of electrons is a key parameter for the effect of Alfvén waves on the growth rate of modes O1, O2, and X2. For a beam-dominated electron distribution ( ϕ 0 ≲ 30 ° ), the growth rates of the maser instability for O1, O2, and X2 modes are enhanced with the increase of the Alfvén wave energy density. In other conditions, the growth rates of O1, O2, and X2 modes weakened with the increasing Alfvén wave intensity, except that the growth of the O1 mode may also be enhanced by Alfvén waves for a ring distribution. The results may be important for us in analyzing the mechanism of radio bursts with various fine structures observed in space and astrophysical plasmas.

  9. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W W; Ruskov, E; Fredrickson, E D; Gorelenkov, N; Medley, S S; Berk, H L; Harvey, R W

    2006-01-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ∼2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (∼<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed

  10. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W W [University of California, Irvine, California (United States); Ruskov, E [University of California, Irvine, California (United States); Fredrickson, E D [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Gorelenkov, N [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Medley, S S [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Berk, H L [University of Texas, Austin, Texas (United States); Harvey, R W [CompX, Del Mar, California (United States)

    2006-09-15

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at {approx}2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power ({approx}<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  11. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    W W,Heidbrink; E,Ruskov; E D,Fredrickson; N,Gorelenkov; S S,Medley; H L,Berk; R W,Harvey

    2006-09-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ~2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50–100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10–20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (≤3MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  12. Ion cyclotron emission due to the newly-born fusion products induced fast Alfven wave radiative instabilities in tokamaks

    International Nuclear Information System (INIS)

    Arunasalam, V.

    1995-08-01

    The velocity distribution functions of the newly born (t = 0) charged fusion products of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v parallel such that v perpendicular ∼ v parallel ∼ v j where (M j V j 2 /2) = E j , the directed birth energy of the charged fusion product species j of mass M j . As the time t progresses these distribution functions will evolve into a Gaussian in velocity with thermal spreadings given by the perpendicular and parallel temperatures T perpendicularj (t) = T parallelj (t) with T j (t) increasing as t increases and finally reaches an isotropic saturation value of T perpendicularj (t ∼ τ j ) = T parallelj (t ∼ τ j ) = T j (t ∼ τ j ) ∼ [M j T d E j /(M j + M)] 1/2 , where T d is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles, respectively, and τ j ∼ τ sj /4 is the thermalization time of the fusion product species j in the background deuterium plasma and τ sj is the slowing-down time. For times t of the order of τ j their distributions can be approximated by a Gaussian in their total energy. Then for times t ≥ τ sj the velocity distributions of these fusion products will relax towards their appropriate slowing-down distributions. Here the authors will examine the radiative stability of all these distributions. The ion cyclotron emission from energetic ion produced by fusion reactions or neutral beam injection promises to be a useful diagnostic tool

  13. Medical Cyclotrons

    Science.gov (United States)

    Friesel, D. L.; Antaya, T. A.

    Particle accelerators were initially developed to address specific scientific research goals, yet they were used for practical applications, particularly medical applications, within a few years of their invention. The cyclotron's potential for producing beams for cancer therapy and medical radioisotope production was realized with the early Lawrence cyclotrons and has continued with their more technically advanced successors — synchrocyclotrons, sector-focused cyclotrons and superconducting cyclotrons. While a variety of other accelerator technologies were developed to achieve today's high energy particles, this article will chronicle the development of one type of accelerator — the cyclotron, and its medical applications. These medical and industrial applications eventually led to the commercial manufacture of both small and large cyclotrons and facilities specifically designed for applications other than scientific research.

  14. Superconducting cyclotrons

    International Nuclear Information System (INIS)

    Blosser, H.G.; Johnson, D.A.; Burleigh, R.J.

    1976-01-01

    Superconducting cyclotrons are particularly appropriate for acceleration of heavy ions. A review is given of design features of a superconducting cyclotron with energy 440 (Q 2 /A) MeV. A strong magnetic field (4.6 tesla average) leads to small physical size (extraction radius 65 cm) and low construction costs. Operating costs are also low. The design is based on established technology (from present cyclotrons and from large bubble chambers). Two laboratories (in Chalk River, Canada and in East Lansing, Michigan) are proceeding with construction of full-scale prototype components for such cyclotrons

  15. Cyclotrons: 1978

    International Nuclear Information System (INIS)

    Martin, J.A.

    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

  16. An experimental study on cyclotron-Cherenkov radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C Y; Masuzaki, M; Yoshida, H; Toyosugi, N; Kamada, K; Ando, R [Kanazawa Univ. (Japan). Department of Physics

    1997-12-31

    Dielectric-loaded cylindrical waveguide configurations with an injected electron beam in which the growth rate of the cyclotron-Cherenkov instability surpasses that of the Cherenkov instability were sought by numerical treatment, and one configuration of this kind was found. This configuration consists of a metallic core and an outer metallic cylinder with a dielectric liner on the inner surface. Based on the calculations, an experimental device was designed and assembled to investigate experimentally radiation due to the cyclotron-Cherenkov instability. Beam propagation in the dielectric-loaded coaxial waveguide and microwave radiation due to the cyclotron-Cherenkov instability and the Cherenkov instability were studied. (author). 6 figs., 10 refs.

  17. Electromagnetic ion-cyclotron instability in the presence of a parallel electric field with general loss-cone distribution function - particle aspect analysis

    Directory of Open Access Journals (Sweden)

    G. Ahirwar

    2006-08-01

    Full Text Available The effect of parallel electric field on the growth rate, parallel and perpendicular resonant energy and marginal stability of the electromagnetic ion-cyclotron (EMIC wave with general loss-cone distribution function in a low β homogeneous plasma is investigated by particle aspect approach. The effect of the steepness of the loss-cone distribution is investigated on the electromagnetic ion-cyclotron wave. The whole plasma is considered to consist of resonant and non-resonant particles. It is assumed that resonant particles participate in the energy exchange with the wave, whereas non-resonant particles support the oscillatory motion of the wave. The wave is assumed to propagate parallel to the static magnetic field. The effect of the parallel electric field with the general distribution function is to control the growth rate of the EMIC waves, whereas the effect of steep loss-cone distribution is to enhance the growth rate and perpendicular heating of the ions. This study is relevant to the analysis of ion conics in the presence of an EMIC wave in the auroral acceleration region of the Earth's magnetoplasma.

  18. Ion cyclotron resonance heating

    International Nuclear Information System (INIS)

    Tajima, T.

    1982-01-01

    Ion cyclotron resonance heating of plasmas in tokamak and EBT configurations has been studied using 1-2/2 and 2-1/2 dimensional fully self-consistent electromagnetic particle codes. We have tested two major antenna configurations; we have also compared heating efficiencies for one and two ion species plasmas. We model a tokamak plasma with a uniform poloidal field and 1/R toroidal field on a particular q surface. Ion cyclotron waves are excited on the low field side by antennas parallel either to the poloidal direction or to the toroidal direction with different phase velocities. In 2D, minority ion heating (vsub(perpendicular)) and electron heating (vsub(parallel),vsub(perpendicular)) are observed. The exponential electron heating seems due to the decay instability. The minority heating is consistent with mode conversion of fast Alfven waves and heating by electrostatic ion cyclotron modes. Minority heating is stronger with a poloidal antenna. The strong electron heating is accompanied by toroidal current generation. In 1D, no thermal instability was observed and only strong minority heating resulted. For an EBT plasma we model it by a multiple mirror. We have tested heating efficiency with various minority concentrations, temperatures, mirror ratios, and phase velocities. In this geometry we have beach or inverse beach heating associated with the mode conversion layer perpendicular to the toroidal field. No appreciable electron heating is observed. Heating of ions is linear in time. For both tokamak and EBT slight majority heating above the collisional rate is observed due to the second harmonic heating. (author)

  19. Medical cyclotrons

    International Nuclear Information System (INIS)

    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

  20. Experimental study of an ion cyclotron instability in a magnetic well confined plasma; Etude experimentale d'une instabilite cyclotronique ionique dans un plasma confine dans un puits magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Brossier, P [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    This report is a contribution to the study of microinstabilities in macroscopically stable plasmas, in the low-{beta} limit. Ion cyclotron instabilities, with k{sub ||} = 0, have been numerically studied in detail; the computation of the density thresholds and growth rates of the different harmonics showed the relative role played by the following energy sources: density gradient, perpendicular distribution function and cold plasma component. This theoretical model has been compared with the results of a detailed study (density thresholds, wave structure, frequency spectrum, wavelengths, growth rate, amplitude of the electric field) of the instability observed in the DECA II device. This comparison gave a good agreement which shows the destabilising role played by the cold plasma component on a hot plasma with a loss cone distribution function. (author) [French] Ce rapport est une contribution a l'etude des microinstabilites dans les plasmas macroscopiquement stables, dans la limite des {beta} << 1. Les instabilites cyclotroniques ioniques, a k{sub ||} = 0, ont ete etudiees numeriquement en detail; le calcul des seuils de densite et taux de croissance des differents harmoniques a permis de preciser l'importance relative des facteurs destabilisants suivants: gradient de densite, fonction de distribution perpendiculaire, presence de plasma froid. Ce modele theorique a ete confronte avec les resultats d'une etude detaillee (seuils de densite, structure de l'onde, spectres de frequence, longueurs d'onde, taux de croissance, amplitude du champ electrique) de l'instabilite observee dans l'experience DECA II, Cette confrontation aboutit a un accord satisfaisant qui montre le role destabilisant joue par le plasma froid sur un plasma chaud presentant une distribution de cone de pertes. (auteur)

  1. Electromagnetic cyclotron harmonic waves

    International Nuclear Information System (INIS)

    Ohnuma, T.; Watanabe, T.; Hamamatsu, K.

    1981-09-01

    Electromagnetic electron cyclotron harmonic waves just below the electron cyclotron harmonics are investigated numerically and experimentally. Backward waves which are observed to propagate nearly perpendicular to the magnetic field just below the electron cyclotron frequency in a high density magnetoplasma are confirmed to be in accord with the theoretical electromagnetic cyclotron waves. (author)

  2. Ponderomotive force near cyclotron resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kono, Mitsuo; Sanuki, Heiji

    1987-01-01

    The ponderomotive force, which is involved in the excitation of macroscopic behaviors of plasma caused by wave motion, plays an important role in various non-linear wave motion phenomena. In the present study, equations for the pondermotive force for plasma in a uniform magnetic field is derived using a renormalization theory which is based on the Vlasov equation. It is shown that the pondermotive force, which diverges at the cyclotron resonence point according to adiabatic approximation, can be expressed by a non-divergent equation by taking into account the instability of the cyclotron orbit due to high-order scattering caused by a wave. This is related with chaotic particle behaviors near cyclotron resonance, where the pondermotive force is small and the diffusion process prevails. It is assumed here that the amplitude of the high-frequency electric field is not large and that the broadening of cyclotron levels is smaller than the distance between the levels. A global chaos will be created if the amplitude of the electric field becomes greater to allow the broadening to exceed the distance between the levels. (Nogami, K.).

  3. Cyclotrons as mass spectrometers

    International Nuclear Information System (INIS)

    Clark, D.J.

    1984-04-01

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures

  4. Medical applications of cyclotrons

    International Nuclear Information System (INIS)

    Jean, R.; Fauchet, M.

    1978-01-01

    Isochronous cyclotrons used to accelerate different charged particles (protons, deuterons, alphas...) at variable energies, have important medical applications, for neutron teletherapy, in vivo or in vitro activation analysis or production of short-lived radioisotopes for nuclear medicine. The characteristics of the cyclotron presently available are described for these three applications (low energy 'compact' cyclotrons, cyclotrons of intermediate and high energies), and their advantages are discussed from the points of view of the medical requirements, the financial investments and the results obtained. (orig.) [de

  5. MICHIGAN: Cyclotron conference

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead

  6. MICHIGAN: Cyclotron conference

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-10-15

    A sense of excitement was in the air as cyclotron physicists and engineers from 17 countries convened on 30 April for the opening of the Tenth International Conference on Cyclotrons and Their Applications. Some 50 years after its invention, the redoubtable cyclotron remains a topic of compelling current interest. Cyclotron experts gathered at Michigan State University's Kellogg Center to hear of latest developments, of progress and successes on new machines which had come into operation, of new projects which were underway, and of dreams which lay ahead.

  7. [Cyclotron based nuclear science

    International Nuclear Information System (INIS)

    1989-06-01

    This report contains papers on the following topics: Heavy ion reactors, nuclear structure and fundamental interactions; atomic and materials studies; nuclear theory; and superconducting cyclotron and instrumentation

  8. Medical cyclotron facilities

    International Nuclear Information System (INIS)

    1984-09-01

    This report examines the separate proposals from the Austin Hospital and the Australian Atomic Energy Commission for a medical cyclotron facility. The proponents have argued that a cyclotron facility would benefit Australia in areas of patient care, availability and export of radioisotopes, and medical research. Positron emission tomography (PET) and neutron beam therapy are also examined

  9. 20 years Rossendorf cyclotron

    International Nuclear Information System (INIS)

    1978-08-01

    On the occasion of the 20th anniversary of initiating of the Rossendorf cyclotron accounts are given of most important works and results in the field of accelerator engineering and utilization of this machine. The reports show the trend of development and actual spectrum of application. The enclosed literature lists give a survey of technical and experimental works at cyclotron. (author)

  10. Vancouver Cyclotron Conference

    International Nuclear Information System (INIS)

    Clark, David J.

    1993-01-01

    Although no longer on the high energy frontier, the cyclotron field is still a major scientific growth area. Its progress is highlighted at the international conference on cyclotron design, development and utilization held at intervals of about three years, under the auspices of the International Union of Pure and Applied Physics (IUPAP). Vancouver, surrounded by mountains, water and some cyclotrons, provided a pleasant setting for the 13th Conference, held last summer. With over 200 cyclotrons in operation around the world, the attendance, 241 delegates and 26 industrial exhibitors, was a near record, reflecting the flourishing state of the field. The early sessions covered the initial operation of new or upgraded cyclotron facilities. Major facilities completed since the previous Conference in Berlin in May 1989 included the 400 MeV ring cyclotron at Osaka, the U400M cyclotron at Dubna which will be coupled to the U400 to give 20 MeV nucléon uranium beams, the 130 MeV cyclotron at Jyvaskyla (in Finland, the furthest north!), the 110 MeV JAERI machine in Japan, and the 65 MeV proton therapy cyclotron in Nice. Among the facility upgrades were the KFA cyclotron at Julich which will inject the 2.5 GeV storage ring COSY, and the addition of an FM mode to the K=200 CW mode at Uppsala to give protons up to 180 MeV. The impressive current of 1.5 mA at 72 MeV obtained from the PSI Injector II will soon be injected into the 590 MeV ring

  11. Cyclotrons for isotope production

    International Nuclear Information System (INIS)

    Milton, B.F.; Stevenson, N.R.

    1995-06-01

    Cyclotrons continue to be efficient accelerators for radioisotope 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 indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  12. 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.

  13. Electromagnetic Cyclotron Waves in the Solar Wind: Wind Observation and Wave Dispersion Analysis

    Science.gov (United States)

    Jian, L. K.; Moya, P. S.; Vinas, A. F.; Stevens, M.

    2016-01-01

    Wind observed long-lasting electromagnetic cyclotron waves near the proton cyclotron frequency on 11 March 2005, in the descending part of a fast wind stream. Bi-Maxwellian velocity distributions are fitted for core protons, beam protons, and alpha-particles. Using the fitted plasma parameters we conduct kinetic linear dispersion analysis and find ion cyclotron and/or firehose instabilities grow in six of 10 wave intervals. After Doppler shift, some of the waves have frequency and polarization consistent with observation, thus may be correspondence to the cyclotron waves observed.

  14. An exact linear dispersion relation for CRM instability

    International Nuclear Information System (INIS)

    Choyal, Y; Minami, K

    2011-01-01

    An exact self-consistent linear dispersion relation of a large orbit electron beam including two principles of cyclotron emission with oscillation frequencies above and below the relativistic electron frequency is derived and analyzed numerically for the first time in the literature. The two principles are cyclotron resonance maser (CRM) instability and Cherenkov instability in the azimuthal direction. Self-consistency in the formulation and inclusion of proper boundary conditions have removed the unphysical instability existing for infinitely large k z observed in conventional dispersion relations of CRM instability.

  15. Slow wave cyclotron maser

    International Nuclear Information System (INIS)

    Kho, T.H.; Lin, A.T.

    1988-01-01

    Cyclotron masers such as Gyrotrons and the Autoresonance Masers, are fast wave devices: the electromagnetic wave's phase velocity v rho , is greater than the electron beam velocity, v b . To be able to convert the beam kinetic energy into radiation in these devices the beam must have an initial transverse momentum, usually obtained by propagating the beam through a transverse wiggler magnet, or along a nonuniform guide magnetic field before entry into the interaction region. Either process introduces a significant amount of thermal spread in the beam which degrades the performance of the maser. However, if the wave phase velocity v rho v b , the beam kinetic energy can be converted directly into radiation without the requirement of an initial transverse beam momentum, making a slow wave cyclotron maser a potentially simpler and more compact device. The authors present the linear and nonlinear physics of the slow wave cyclotron maser and examine its potential for practical application

  16. Observation of Poincaré-Andronov-Hopf Bifurcation in Cyclotron Maser Emission from a Magnetic Plasma Trap

    Science.gov (United States)

    Shalashov, A. G.; Gospodchikov, E. D.; Izotov, I. V.; Mansfeld, D. A.; Skalyga, V. A.; Tarvainen, O.

    2018-04-01

    We report the first experimental evidence of a controlled transition from the generation of periodic bursts of electromagnetic radiation into the continuous-wave regime of a cyclotron maser formed in magnetically confined nonequilibrium plasma. The kinetic cyclotron instability of the extraordinary wave of weakly inhomogeneous magnetized plasma is driven by the anisotropic electron population resulting from electron cyclotron plasma heating in a MHD-stable minimum-B open magnetic trap.

  17. The electron cyclotron instabiity of a beam-plasma system immersed in a magnetic beach

    International Nuclear Information System (INIS)

    Varandas, C.A.F.; Cabral, J.A.C.

    1982-01-01

    The linear development of the electron cyclotron instability of a beam-plasma system in a magnetic beach is studied. Beaches of positive as well as negative B-field gradients are considered. The experimental results concerning the excited instability spectra are interpreted in terms of local dispersion analysis. (Author) [pt

  18. Cyclotron to Oslo University

    International Nuclear Information System (INIS)

    Sandstad, J.

    1978-01-01

    The new cyclotron was delivered to Oslo University on September 21st 1978, and was mannfactured by A/B Scandtronix of Uppsala, Sweden. The contract price was 6,8 million Norwegian kroner and installation will cost a further 4 million. The main specifications are given. The energy will be 36 MeV for protons and alpha particles, 18 MeV deuterons and 48 MeV for helium 3. The principle of a cyclotron is briefly described. While the primary purpose of the machine is nuclear research it is also planned to produce short-lived radioisotopes, primarily iodine 123. (JIW)

  19. How cyclotrons work

    International Nuclear Information System (INIS)

    Nolan, D.

    1992-01-01

    The operating principles of a cyclic accelerator are presented based on the IBA Cyclone 30 negative ion cyclotron, selected for the Australia's first medical cyclotron. Its main features are: acceleration with variable energy of between 15-30 million electron volts, the capability of extracting two beams simultaneously, low power consumption, easy maintenance. Other aspects not directly related to the principle of operation discussed include the vacuum and the radio-frequency systems as well as the complex computerized control system used to automatically control start-up and shut-down operations. ills

  20. National Medical Cyclotron

    International Nuclear Information System (INIS)

    Boyd, Rex.

    1991-01-01

    The National Medical Cyclotron, under construction at Sydney's Royal Prince Alfred Hospital(RPAH) is to be operated by the Australian Nuclear Science and Technology Organization in collaboration with the hospital. Its main purpose is to produce radioisotopes on commercial basis for distribution to hospitals through Australia as well as short-lived radioisotopes (2 minutes to 2 hours) for immediate application at RPAH in Positron Emission Tomography, to study the dynamics of human physiology and metabolism in organs, bones and soft tissues. A list of the principal cyclotron-produced radionuclides is provided. ills

  1. Ramifide resonators for cyclotrons

    International Nuclear Information System (INIS)

    Smirnov, Yu.V.

    2000-01-01

    The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru

  2. About the magneto-acoustic instabilities in mirrors

    International Nuclear Information System (INIS)

    Zvonkov, A.V.; Timofeev, A.V.

    1984-01-01

    It is shown that the characteristic of a plasma in mirrors anisotropy of io on distribution function versus velocities may results in the drive of magneto-acoustic instabilities. This instability, in contast to the well known Alyven oscillation instability, is driven on ion cyclotron frequency harmonics The instability in question has been possibly observed during the experiments a at the tmx device, where the oscillations have been excited both at the ion cycl tron frequency and harmonics

  3. Electron cyclotron heating (ECH) of tokamak plasmas

    International Nuclear Information System (INIS)

    Hoshino, Katsumichi

    1990-01-01

    Electron cyclotron heating (ECH) is one of the intense methods of plasma heating, and which utilizes the collisionless electron-cyclotron-resonance-interaction between the launched electromagnetic waves (called electron cyclotron waves) and electrons which are one of the constituents of the high temperature plasmas. Another constituent, namely the ions which are subject to nuclear fusion, are heated indirectly but strongly and instantly (in about 0.1 s) by the collisions with the ECH-heated electrons in the fusion plasmas. The recent progress on the development of high-power and high-frequency millimeter-wave-source enabled the ECH experiments in the middle size tokamaks such as JFT-2M (Japan), Doublet III (USA), T-10 (USSR) etc., and ECH has been demonstrated to be the sure and intense plasma heating method. The ECH attracts much attention for its remarkable capabilities; to produce plasmas (pre-ionization), to heat plasmas, to drive plasma current for the plasma confinement, and recently especially by the localization and the spatial controllability of its heating zone, which is beneficial for the fine controls of the profiles of plasma parameters (temperature, current density etc.), for the control of the magnetohydrodynamic instabilities, or for the optimization/improvement of the plasma confinement characteristics. Here, the present status of the ECH studies on tokamak plasmas are reviewed. (author)

  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. Biomedical cyclotron facility

    International Nuclear Information System (INIS)

    MacDonald, N.S.; Birdsall, R.; Takahaski, J.; McConnel, L.; Wood, R.; Wakakuwa, S.

    1976-01-01

    During the fifth year of operation the mechanical performance of the cyclotron and accessory equipment was excellent. Major items put into operation were a small computer system interfaced with Ge-Li gamma spectrometer and a pneumatic-tube system for fast delivery of short-lived radionuclides. A table is presented listing the radionuclides produced

  6. Cyclotron tubes - a theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Mourier, G

    1980-12-01

    The introduction presents a general discussion of electron cyclotron masers (ECM): resonance, relativistic effects, elementary quantum aspects, the classical relativistic bunching and the optimum value of the electric field. The practical structure - in particular that of the gyrotron - is specified only insofar as it is useful for understanding the following chapters. The main parameters are discussed. Section 2 develops a nonlinear adiabatic or orbital theory of electron motion which alleviates calculations considerably while keeping numerical errors low enough for many practical cases. Its results are compared to a rigorous integration in one case. Other cases show the importance of the electric field profile inside the resonant cavity. Section 3 is devoted to space charge phenomena, and, for the most part, to a linear theory with space charge. In its limited range of validity (low-energy electrons), the theory indicates a strong impact of space charge for low a.c. fields and exhibits a pure beam instability. Section 4 is devoted to circuit equations with emphasis on the special features of cavities consisting of a long waveguide near cutoff. The conclusion indicates some trends of gyrotron development and corresponding theoretical problems.

  7. Goodbye Synchro-Cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-12-15

    On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s.

  8. Goodbye Synchro-Cyclotron

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    On 17 December, after having seen many other physics machines come and go during its 33-year career, CERN's 600 MeV SynchroCyclotron (SC) is being shut down. Judged simply by its length (to say nothing of its quality), the research career of this machine testifies to the wisdom and imagination of the CERN pioneers who proposed it in the early 1950s

  9. Cyclotrons in developing countries

    International Nuclear Information System (INIS)

    Vera Ruiz, Hernan

    2004-01-01

    Cyclotron accelerators are prolific sources of charged particle for the production of radionuclides and have become an essential tool in the practice of modern nuclear medicine by providing reliable radiotracers for SPECT and PET studies. In a recent survey conducted by the IAEA in 2001, the growth in the number of cyclotron facilities installed in laboratories and hospitals in developed as well as developing countries was recorded. This trend, which started in the late 70's, continues in the present time also and all indications are that it will continue in the next five to ten years. The reasons for this growth are several: technology involved has become more user or 'hospital friendly', third party reimbursement for several clinical studies based on F-18 PET radiopharmaceuticals at least in some of the advanced countries started in 1998 and above all, the clear irrefutable and demonstrable conclusion of the positive cost/benefit outcomes of PET studies in the field of oncology to a lesser degree, thus far, for cardiology and neurology. It is however recognizable that the overall financial cost of the technology, which comprises the premises to house the facility, the cyclotron accelerator, the corresponding radiochemistry and quality control equipment and the PET cameras can be nevertheless an expensive proposition that requires careful advance planning. This fact is even more relevant when the facility is planned for installation in a developing country, which, frequently, in addition to having a lack of sufficient financial resources, do have shortage of qualified human resources to efficiently run the facility. In spite of the above, it is fact that more and more public as well as private organizations in the developing countries are setting up cyclotron/PET programmes or are seriously considering the installation of such a facility

  10. Startup work on Inshas cyclotron

    International Nuclear Information System (INIS)

    Vorogushin, M.F.; Strokach, A.P.; Shikhov, V.Ya.; Galchuk, A.V.; Soliman, A.N.; El-Abyad, M.; Comsan, M.N.H.; Saleh, Z.A.; Azzam, A.N.

    2001-01-01

    Startup works on the MGC-20 variable energy cyclotron in the Inshas Nuclear Research Center (Egypt) are described. The cyclotron is intended for acceleration of hydrogen and helium ions in a wide energy range (for protons - from 5 to 20 MeV). Main units of the cyclotron and results of computer experimental acceleration of protons to 18 MeV are described. The prospects of furthers investigations are presented [ru

  11. Ion cyclotron-resonance heating in a toroidal octupole

    International Nuclear Information System (INIS)

    Barter, J.D.; Sprott, J.C.

    1975-01-01

    rf power near the ion cyclotron-resonance frequency has been used to produce a hundredfold increase (from approximately-less-than1 to approx.100 eV) in the ion temperature in a toroidal octupole device. The heating produces no noticeable instabilities or other deleterious effects except for a high reflux of neutrals from the walls. The heating rate is consistent with theory and the limiting ion temperature is determined by charge-exchange losses

  12. Nonlinear parametric phenomena in plasma during radio frequency heating in the ion cyclotron frequency range

    International Nuclear Information System (INIS)

    Stepanov, K.N.

    1996-01-01

    Parametric phenomena in plasma which occur due to varying electric fields with the ion cyclotron frequency are reviewed. Beam-like lower hybrid instability emerges in strong pumping fields provided that the transverse relative velocity of particles is larger than the ion thermal speed (υ Ti ). The resulting turbulence and the following numerous manifestations observed experimentally are addressed. The turbulence may prove important for experiments aimed at plasma production or radio frequency (RF) cleaning of metallic surfaces of vacuum chambers in stellarators, tokamaks and helicon devices. In contrast, for a weak field (U Ti ) the kinetic parametric instabilities of ion cyclotron oscillations arise due to electrons. The issues of the turbulence, mathematical modelling, its role in turbulent heating observed on the torsatron Uragan-3M, decay instabilities associated with ion cyclotron oscillations and the triggering of ion quasimodes are considered. (author)

  13. Electron beam instabilities in gyrotron beam tunnels

    International Nuclear Information System (INIS)

    Pedrozzi, M.; Alberti, S.; Hogge, J.P.; Tran, M.Q.; Tran, T.M.

    1997-10-01

    Electron beam instabilities occurring in a gyrotron electron beam can induce an energy spread which might significantly deteriorate the gyrotron efficiency. Three types of instabilities are considered to explain the important discrepancy found between the theoretical and experimental efficiency in the case of quasi-optical gyrotrons (QOG): the electron cyclotron maser instability, the Bernstein instability and the Langmuir instability. The low magnetic field gradient in drift tubes of QOG makes that the electron cyclotron maser instability can develop in the drift tube at very low electron beam currents. Experimental measurements show that with a proper choice of absorbing structures in the beam tunnel, this instability can be suppressed. At high beam currents, the electrostatic Bernstein instability can induce a significant energy spread at the entrance of the interaction region. The induced energy spread scales approximately linearly with the electron beam density and for QOG one observes that the beam density is significantly higher than the beam density of an equivalent cylindrical cavity gyrotron. (author) figs., tabs., refs

  14. Comparative study of the loss cone-driven instabilities in the low solar corona

    Science.gov (United States)

    Sharma, R. R.; Vlahos, L.

    1984-01-01

    A comparative study of the loss cone-driven instabilities in the low solar corona is undertaken. The instabilities considered are the electron cyclotron maser, the whistler, and the electrostatic upper hybrid. It is shown that the first-harmonic extraordinary mode of the electron cyclotron maser instability is the fastest growing mode for strong magnetized plasma (the ratio of plasma frequency to cyclotron frequency being less than 0.35). For values of the ratio between 0.35 and 1.0, the first-harmonic ordinary mode of the electron cyclotron maser instability dominates the emission. For ratio values greater than 1.0, no direct electromagnetic radiation is expected since other instabilities, which do not escape directly, saturate the electron cyclotron maser (the whistler or the electrostatic upper hybrid waves). It is also shown that the second-harmonic electron cyclotron maser emission never grows to an appreciable level. Thus, it is suggested that the electron cyclotron maser instability can be the explanation for the escape of the first harmonic from a flaring loop.

  15. Solid targetry for compact cyclotrons

    International Nuclear Information System (INIS)

    Comor, J.

    2004-01-01

    In this presentation authors present experimental results of solid targetry for compact cyclotrons. It is concluded: Solid targetry is not restricted to large accelerator centers anymore; Small and medium scale radioisotope production is feasible with compact cyclotrons; The availability of versatile solid target systems is expected to boost the radiochemistry of 'exotic' positron emitters

  16. 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)

  17. Status report on cyclotron operation

    International Nuclear Information System (INIS)

    Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Fenyvesi, A.; Ditroi, F.; Takacs, S.; Tarkanyi, F.

    2004-01-01

    The operation of the cyclotron in 2003 was again concentrated to 9 months; January, July and August were reserved for maintenance, renewal works and holidays. The overall working time of the accelerator was 4051 hours. The cyclotron was available for users for 3682 hours. In order to improve the circumstances of the irradiations renewal and improvements were done. (N.T.)

  18. Cyclotrons and positron emitting radiopharmaceuticals

    International Nuclear Information System (INIS)

    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

  19. Medical cyclotron: why, where, how

    International Nuclear Information System (INIS)

    Scheer, Kurt; Comar, Dominique; Kellershohn, Claude

    1976-01-01

    Cyclotrons for medical purposes are particularly useful for the production of radioactive isotopes of elements normally constituting organic matter ( 15 O, 13 N, 11 C). The short half-life and positron emission of those elements are of great interest in medical diagnosis. Many others carrier-free radioisotopes can be produced by cyclotrons. Three categories of cyclotrons are mentioned. Desk top cyclotron only adapted to the production of short-lived radioisotopes in a hospital; low energy and average energy cyclotrons which require well-entrained personnel for their operation and are best adapted to the production of radioelements on a regional or even national scale. Examples relative to the interest of short-lived radioisotopes in lung and brain investigations and tumor detection are given

  20. JSW's baby cyclotron

    International Nuclear Information System (INIS)

    Toda, Y.; Kaneda, Y.; Satoh, Y.; Suzukawa, I.; Yamada, T.

    1983-01-01

    Designed by The Japan Steel Works, Ltd., specially for installation in a hospital's medical department and nuclear research laboratory, '' JSW BABY CYCLOTRON '' has been developed to produce short-lived radioisotopes such as 11C, 13N, 15O and 18F. JSW's Baby Cyclotron has some design features. 1) Fixed energy and four sector azimuthally varying field. 2) Compact figure desired for hospital's nuclear medical department 3) A bitter type magnet yoke shielding activity 4) Simple control and operation 5) Easy maintenance without skilled personnel. Type BC105 (P:10MeV, d:5MeV), BC107 (P:10MeV, d:7MeV), BC168 (P:16MeV, d:8MeV) and BC1710 (P:17MeV, d:10MeV) are available according to required amount of radioisotopes. In our radioisotope production test, yield and purity of 11C, 13N, 15O and 18F are usable to clinical diagnosis

  1. Cyclotron produced radiopharmaceuticals

    International Nuclear Information System (INIS)

    Kopicka, K.; Fiser, M.; Hradilek, P.; Hanc, P.; Lebeda, O.

    2003-01-01

    Some of the cyclotron-produced radionuclides may serve as important materials for the production of radiopharmaceuticals. This lecture deals with basic information relating to various aspects of these compounds. In comparison with radionuclides /compounds used for non-medical purposes, radiopharmaceuticals are subject to a broader scale of regulations, both from the safety and efficacy point of view; besides that, there are both radioactive and medical aspects that must be taken into account for any radiopharmaceutical. According to the regulations and in compliance with general rules of work with radioactivity, radiopharmaceuticals should only be prepared/manufactured under special conditions, using special areas and special equipment and applying special procedures (e.g. sterilisation, disinfection, aseptic work). Also, there are special procedures for cleaning and maintenance. Sometimes the requirements for the product safety clash with those for the safety of the personnel; several examples of solutions pertaining to these cases are given in the lecture. Also, the specific role of cyclotron radiopharmaceuticals is discussed. (author)

  2. Comparative study of the loss cone-driven instabilities in the low solar corona

    International Nuclear Information System (INIS)

    Sharma, R.R.; Vlahos, L.

    1984-01-01

    A comparative study of the loss cone--driven instabilities in the low solar corona is undertaken. The instailities considered are the electron maser, the whistler, and the electrostatic upper hybrid. We show that the first-harmonic extraordinary mode of the electron cyclotron maser instability is the fastest growing mode for strongly magnetized plasma (ω/sub e//Ω/sub e/ 1.0, no direct electromagnetic radiation is expected since other instabilities, which do not escape directly, saturate the electron cyclotron maser (the whistler or the electrostatic upper hybrid waves). We also show that the second-harmonic electron cyclotron maser emission never grows to an appreciable level. Thus, we suggest that the electron cyclotron maser instability can be the explanation for intense radio bursts only when the first harmonic escapes from the low corona. We propose a possible explanation for the escape of the first harmonic from a flaring loop

  3. Applied research with cyclotrons

    International Nuclear Information System (INIS)

    Apel, P.; Dmitriev, S.; Gulbekian, G.; Gikal, B.; Ivanov, O.; Reutov, V.; Skuratov, V.

    2005-01-01

    During the past three decades the Flerov laboratory carried out research and development of a number of applications that have found or may find use in modern technologies. One of the applications is the so-called ion track technology enabling us to create micro- and nano-structured materials. Accelerated heavy ion beams are the unique tools for structuring insulating solids in a controllable manner. At FLNR JINR the U-400 cyclotron and the IC-100 cyclotron are employed for irradiation of materials to be modified by the track-etch technique. For practical applications, U-400 delivers the 86 Kr ion beams with total energies of 250, 350, 430 and 750 MeV, and the 136 Xe ion beams with the energy of 430 MeV. The cyclotron is equipped with a specialized channel for irradiation of polymer foils. IC-100 is a compact accelerator specially designed for the technological uses. High-intensity krypton ion beams with the energy of ∼ 1 MeV/u are available now at IC-100. Production of track-etch membranes is an example of mature technology based on irradiation with accelerated ions. The track-etch membranes offer distinct advantages over other types of membranes due to their precisely determined structure. One-pore, oligo-pore and multi-pore samples can serve as models for studying the transport of liquids, gases, particles, solutes, and electrolytes in narrow channels. Track-etch pores are also used as templates for making nano wires, nano tubes or array of nano rods. The microstructures obtained this way may find use in miniaturized devices such as sensors for biologically important molecules. Bulk and surface modification for the production of new composites and materials with special optical properties can be performed with ion beams. Flexible printed circuits, high-performance heat transfer modules, X-ray filters, and protective signs are examples of products developed in collaboration with research and industrial partners. Some recent achievements and promising ideas that

  4. Isochronous cyclotron data base description

    International Nuclear Information System (INIS)

    Kiyan, I.N.; Vorozhtsov, S.B.; Tarashkevich, R.

    2004-01-01

    The relational data base of the control parameters of the isochronous cyclotron, Isochronous Cyclotron Data Base (ICDB), is described. The relational data base under consideration, written in Transact SQL for the MS SQL Server 2000 with the use of MS Enterprise Manager and MS Query Analyzer, was installed on the server of the AIC144 isochronous cyclotron in Krakow, which operates under the control of the operating system MS Windows Server 2003 (Standard Edition). The interface of the data base under considerations is written in C++ with the use of Visual C++ .NET and is built in the Cyclotron Operator Help Program (COHP), which is used for modeling the operational modes of the isochronous cyclotron. Communication between the COHP and the relational data base is realised on the base of the Open Data Base Connectivity protocol. The relational data base of the control parameter of the isochronous cyclotron is intended: firstly, for systematization and automatic use of all measured and modelled magnetic field maps in the process of modeling the operational modes; secondly, for systematization and convenient access to the stored operational modes; thirdly, for simplifying the operator's work. The relational data base of the control parameter of the isochronous cyclotron reflects its physical structure and the logic of its operator's work. (author)

  5. [Cyclotron based nuclear science

    International Nuclear Information System (INIS)

    1991-08-01

    This report contains descriptions of research programs carried out by Institute staff, as well as progress on new instrumentation during the period, April 1, 1990, to March 31, 1991. The K500 cyclotron and ECR source provided beam for 4140 hours during the period. The beam was actually available for experiments 1927.50 hours and 1110.50 hours was devoted to developing new beams and exploring cyclotron performance. A wide range of beams from protons to Xe with energies from 2.4 MeV/u to 60 MeV/U have been used in experiments. The highest total energy beam accelerated was 35 MeV/u 63 Cu. The ECR source, made a tremendous improvement in accelerator performance and reliability. Substantial amounts of beam time were devoted to investigations of hot nuclei, electron-positron, giant resonances, atomic effects of high velocity ion beams, astrophysics related reactions and proton and alpha bremsstrahlung. Scientific accomplishments included determination of the heat capacity of nuclei through new insight into the level densities and establishing a lower limit for electron positron resonances a factor of ten better than previous measurements. The proton spectrometer, constructed for studies of the Gamow-Teller interaction is complete, and initial physics measurements will be made in the next few months. All of the BaF 2 crystals have been delivered and acceptance tests are underway. A K=315 MDM spectrometer has been obtained from Oxford University and is scheduled for installation in Spring 1992, after removal of the K=150 Enge split pole spectrometer. Institute groups continue participation in MEGA, instrumentation projects for RHIC, and few nucleon studies at LAMPF and KEK. Reports of these activities are included

  6. The importance of plasma effects on electron-cyclotron maser-emission from flaring loops

    Science.gov (United States)

    Sharma, R. R.; Vlahos, L.; Papadopoulos, K.

    1982-01-01

    Electron cyclotron maser instability has been suggested as the cause of the observed short (10-20 msec), intense (an approximate brightness temperature of 10 to the 15th K) and up to 100% polarized microwave solar emission. It is shown that plasma effects and thermal cyclotron damping, ignored in previous theories, play an important role in controlling the frequency range of the emission. The radio emission is suppressed for ratios of the plasma frequency to the cyclotron frequency smaller than 0.4. An examination of the cyclotron damping, reveals that the maser action is suppressed unless a large fraction (i.e., over 10%) of the accelerated electrons participates in the emission process.

  7. Design Study of a Mini Cyclotron for the Application of Biomedical Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Kim, Jong-Won; Yun, Chong-Chul; Youn, Min-Yong; Wang, Sonjong

    2009-01-01

    A small cyclotron has been considered for the use of biomedical accelerator mass spectrometer (BAMS). Over a decade ago a few cyclotrons had been constructed and tested for AMS, but technical problems of instability and poor transmission efficiency caused to discontinue further developments. The major reason of the demise of cyclotron AMS was the dominance of commercial Tandem-based AMS facilities. Now BAMS may ask for more compact system, and perhaps using positive ions to accelerate isotope tracers is a favorable feature. The design of a cyclotron to meet the requirements of BAMS has been performed by adopting a compact magnet with high stability and a flat-topping rf system to increase transmission efficiency.

  8. 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...

  9. Present and future superconducting cyclotrons

    International Nuclear Information System (INIS)

    Nolen, J.A. Jr.

    1987-01-01

    This paper begins with a brief review of the status of present superconducting (SC) cyclotron projects, including the two which are currently operating and the six which are under construction. The next section summarizes the main features shared by five of these machines, while the third section presents recent developments and new concepts introduced in the other three ''second generation'' SC cyclotrons. Projects in early stages of development are discussed in the fourth section

  10. Injection and extraction for cyclotrons

    International Nuclear Information System (INIS)

    Heikkinen, P.

    1994-01-01

    External ion sources for cyclotrons are needed for polarised and heavy ions. This calls for injection systems, either radial or axial. Radial injection is also needed when a cyclotron works as a booster after another cyclotron or a linear accelerator (usually tandem). Requirements for injection differ from separated sector cyclotrons where there is plenty of room to house inflectors and/or strippers, to superconducting cyclotrons where the space is limited by a small magnet gap, and high magnetic field puts other limitations to the inflectors. Several extraction schemes are used in cyclotrons. Stripping injection is used for H - and also for heavy ions where the q/m ratio is usually doubled. For other cases, electric and magnetic deflection has to be used. To increase the turn separation before the first deflector, both resonant and non-resonant schemes are used. In this lecture, external injection systems are surveyed and some rules to thumb for injection parameters are given. Extraction schemes are also reviewed. (orig.)

  11. 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.

  12. Tachyonic cyclotron radiation

    International Nuclear Information System (INIS)

    Tomaschitz, R.

    2006-01-01

    We study superluminal cyclotron emission by electrons and muons in semiclassical orbits. The tachyonic line spectra of hydrogenic ions such as H, 56 Fe 25+ , and 238 U 91+ , as well as their muonic counterparts pμ - , 56 Fe 26+ μ - and 238 U 92+ μ - are calculated, in particular the tachyonic power transversally and longitudinally radiated, the total intensity, and the power radiated in the individual harmonics. We also investigate tachyonic continuum radiation from electrons and protons cycling in the surface and light cylinder fields of γ -ray and millisecond pulsars, such as the Crab pulsar, PSR B1509-58, and PSR J0218 + 4232. The superluminal spectral densities generated by non-relativistic, mildly relativistic and ultra-relativistic source particles are derived. We study the parameters determining the global shape of the transversal and longitudinal densities and the energy scales of the broadband spectrum. The observed cutoff frequency in the γ-ray band of the pulsars is used to infer the upper edge of the orbital energy, and we conclude that electrons and nuclei cycling in the surface fields can reach energies beyond the ''ankle'' of the cosmic ray spectrum. This suggests γ-ray pulsars as sources of ultra-high energy cosmic rays. (orig.)

  13. Simulation and quasilinear theory of proton firehose instability

    Energy Technology Data Exchange (ETDEWEB)

    Seough, Jungjoon [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Faculty of Human Development, University of Toyama, 3190, Gofuku, Toyama City, Toyama, 930-8555 (Japan); Yoon, Peter H. [University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Hwang, Junga [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Korea, University of Science and Technology, Daejeon (Korea, Republic of)

    2015-01-15

    The electromagnetic proton firehose instability is driven by excessive parallel temperature anisotropy, T{sub ∥} > T{sub ⊥} (or more precisely, parallel pressure anisotropy, P{sub ∥} > P{sub ⊥}) in high-beta plasmas. Together with kinetic instabilities driven by excessive perpendicular temperature anisotropy, namely, electromagnetic proton cyclotron and mirror instabilities, its role in providing the upper limit for the temperature anisotropy in the solar wind is well-known. A recent Letter [Seough et al., Phys. Rev. Lett. 110, 071103 (2013)] employed quasilinear kinetic theory for these instabilities to explain the observed temperature anisotropy upper bound in the solar wind. However, the validity of quasilinear approach has not been rigorously tested until recently. In a recent paper [Seough et al., Phys. Plasmas 21, 062118 (2014)], a comparative study is carried out for the first time in which quasilinear theory of proton cyclotron instability is tested against results obtained from the particle-in-cell simulation method, and it was demonstrated that the agreement was rather excellent. The present paper addresses the same issue involving the proton firehose instability. Unlike the proton cyclotron instability, however, it is found that the quasilinear approximation enjoys only a limited range of validity, especially for the wave dynamics and for the relatively high-beta regime. Possible causes and mechanisms responsible for the discrepancies are speculated and discussed.

  14. [Cyclotron based nuclear science

    International Nuclear Information System (INIS)

    1993-07-01

    The period 1 April 1992--31 March 1993 saw the initial runs of three new spectrometers, which constitute a major portion of the new detection capabilities developed for this facility. These devices are the Proton Spectrometer (PSP) (data from which are shown on the cover of this document), the Mass Achroniat Recoil Mass Spectrometer (MARS), and the Multipole Dipole Multipole (MDM) Particle Spectrometer. The ECR-K500 cyclotron combination operated 5,849 hours. The beam was on target 39% of this time. Studies of nuclear dynamics and nuclear thermodynamics using the neutron ball have come to fruition. A critical re-evaluation of the available data on the giant monopole resonance indicated that the incompressibility is not specified to a range smaller than 200--350 MeV by those data. New systematic experiments using the MDM spectrometer are now underway. The MEGA collaboration obtained the first data on the μ → eγ decay rate and determination of the Michel parameter in normal μ decay. Experiments appear to confirm the existence of monoenergetic pair peaks even for relatively low Z projectile -- Z target combinations. Studies of the (α,2α) knockout reaction indicate that this reaction may prove to be a valuable tool for determination of reaction rates of astrophysical interest. Theoretical work reported in this document ranges from nuclear structure calculations using the IBM-2 model to calculations of kaon production and the in-medium properties of the rho and phi mesons. Nuclear dynamics and exotic shapes and fragmentation modes of hot nuclei are also addressed. New measurements of x-ray emission from highly ionized ions, of molecular dissociation and of surface interactions are reported. The research is presented in nearly 50 brief summaries usually including data and references

  15. Electromagnetic waves near the proton cyclotron frequency: Stereo observations

    Energy Technology Data Exchange (ETDEWEB)

    Jian, L. K. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Wei, H. Y.; Russell, C. T. [Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095 (United States); Luhmann, J. G. [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States); Klecker, B. [Max-Planck-Institut für Extraterrestrische Physik, D-85741 Garching (Germany); Omidi, N. [Solana Scientific Inc., Solana Beach, CA 92075 (United States); Isenberg, P. A. [Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824 (United States); Goldstein, M. L.; Figueroa-Viñas, A. [Heliophysics Science Division, NASA Goddard Space Flight Center, MD 20771 (United States); Blanco-Cano, X., E-mail: lan.jian@nasa.gov [Instituto de Geofisica, Universidad Nacional Autónoma de México, Coyoacán D.F. (Mexico)

    2014-05-10

    Transverse, near-circularly polarized, parallel-propagating electromagnetic waves around the proton cyclotron frequency were found sporadically in the solar wind throughout the inner heliosphere. They could play an important role in heating and accelerating the solar wind. These low-frequency waves (LFWs) are intermittent but often occur in prolonged bursts lasting over 10 minutes, named 'LFW storms'. Through a comprehensive survey of them from Solar Terrestrial Relations Observatory A using dynamic spectral wave analysis, we have identified 241 LFW storms in 2008, present 0.9% of the time. They are left-hand (LH) or right-hand (RH) polarized in the spacecraft frame with similar characteristics, probably due to Doppler shift of the same type of waves or waves of intrinsically different polarities. In rare cases, the opposite polarities are observed closely in time or even simultaneously. Having ruled out interplanetary coronal mass ejections, shocks, energetic particles, comets, planets, and interstellar ions as LFW sources, we discuss the remaining generation scenarios: LH ion cyclotron instability driven by greater perpendicular temperature than parallel temperature or by ring-beam distribution, and RH ion fire hose instability driven by inverse temperature anisotropy or by cool ion beams. The investigation of solar wind conditions is compromised by the bias of the one-dimensional Maxwellian fit used for plasma data calibration. However, the LFW storms are preferentially detected in rarefaction regions following fast winds and when the magnetic field is radial. This preference may be related to the ion cyclotron anisotropy instability in fast wind and the minimum in damping along the radial field.

  16. Electron cyclotron harmonic wave acceleration

    Science.gov (United States)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  17. Electron cyclotron harmonic wave acceleration

    International Nuclear Information System (INIS)

    Karimabadi, H.; Menyuk, C.R.; Sprangle, P.; Vlahos, L.; Salonika Univ., Greece)

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts. 31 references

  18. Present situation of 'baby cyclotron'

    International Nuclear Information System (INIS)

    Yamada, Teruo

    1981-01-01

    A ''baby cyclotron'' has been developed by the Japan Steel Works, Ltd. Its No. 1 model (proton 9.4 MeV) was delivered to the Nakano Hospital of National Sanatorium in March, 1979. It is being used successfully for the production of 11 C, 13 N and 15 O and labeled compounds. The proton or deuteron particles accelerated in the cyclotron collide on target materials. The target box, which is automatically changeable, is directly installed to the accelerating box, thereby taking the safety measures for any leaking radiation. The following matters are described: the production of short-lived radioisotopes (RI yields and treatment); the processes of production in the Nakano Hospital, with No. 1 baby cyclotron, including the photosynthesis of labeled compounds such as 11 C-labeled glucose; the research on the automation in the synthesis of organic labeled compounds like 11 C-palmitic acid. (J.P.N.)

  19. Status Report on Cyclotron Operation

    International Nuclear Information System (INIS)

    Kovacs, P.; Szuecs, I.; Ander, I.; Lakatos, T.; Tarkanyi, F.

    2004-01-01

    Complete text of publication follows. The operation of the cyclotron in 2004 was concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 3554 hours, the time used for systematic maintenance was 450 hours. The breakdown periods amounted to 70 hours last year, included in it a 50 hours repair of RF control module under guarantee. The cyclotron was available for users during 3034 hours. The effectively used beam-on-target time statistics is summarized in Table 1. Developments: A new measuring site with a HPGe detector based gamma spectrometer is under installation in the basement of the Cyclotron Laboratory. A two channel pneumatic rabbit system is also under development to enable fast transport of samples between the new measuring site and two irradiation sites (the low intensity fast neutron irradiation site and the beam line used for Thin Layer Activation). (author)

  20. Development of Medical Cyclotron in KIRAMS

    International Nuclear Information System (INIS)

    Chai, Jong Seo; Jung, In Su; An, Dong Hyun

    2005-01-01

    This paper is presented on the development and status of medical cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) at present. We have developed medical cyclotron which is KIRAMS-13. And the improvement of KIRAMS-13 is presented. Furthermore, the design of new cyclotrons, such as KIRAMS-5 and KIRAMS-30 cyclotron, are presented, and R and D studies for future plan of heavy ion accelerator are discussed

  1. Decay instability of a whistler in a plasma

    International Nuclear Information System (INIS)

    Tewari, D.P.; Sharma, R.R.

    1982-01-01

    The parametric instabilities of a high power whistler in a high density plasma possess large growth rate when the scattered sideband is an electrostatic lower hybrid mode. The efficient channels of decay include oscillating two stream instability, nonlinear Landau damping and resonant decay involving ion acoustic and ion cyclotron modes. The processes of nonlinear scattering, i.e., the ones possessing whistler sidebands are relatively less significant. (author)

  2. MC-50 AVF cyclotron operation

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong

    1995-12-01

    The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .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 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs.

  3. MC-50 AVF cyclotron operation

    International Nuclear Information System (INIS)

    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 20-60μA. 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

  4. 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.

  5. The development of cyclotron radiopharmaceuticals

    International Nuclear Information System (INIS)

    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 develop the 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 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

  6. MC-50 AVF cyclotron operation

    International Nuclear Information System (INIS)

    Chae, Jong Seo; Lee, Dong Hoon; Kim, You Seok; Park, Chan Won; Lee, Yong Min; Hong, Sung Seok; Lee, Min Yong.

    1995-12-01

    The first cyclotron in Korea, MC-59 cyclotron is used for neutron irradiation, radionuclide development, production and material and biomedical research. 50.5MeV and 35MeV proton beam have been extracted with 20-70 .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 23days. Fundamental data for failure decrement and efficient beam extraction were composed and maintenance technologies were developed. (author). 8 tabs., 17 figs., 10 refs

  7. Carpal instability

    International Nuclear Information System (INIS)

    Schmitt, R.; Froehner, S.; Coblenz, G.; Christopoulos, G.

    2006-01-01

    This review addresses the pathoanatomical basics as well as the clinical and radiological presentation of instability patterns of the wrist. Carpal instability mostly follows an injury; however, other diseases, like CPPD arthropathy, can be associated. Instability occurs either if the carpus is unable to sustain physiologic loads (''dyskinetics'') or suffers from abnormal motion of its bones during movement (''dyskinematics''). In the classification of carpal instability, dissociative subcategories (located within proximal carpal row) are differentiated from non-dissociative subcategories (present between the carpal rows) and combined patterns. It is essential to note that the unstable wrist initially does not cause relevant signs in standard radiograms, therefore being ''occult'' for the radiologic assessment. This paper emphasizes the high utility of kinematographic studies, contrast-enhanced magnetic resonance imaging (MRI) and MR arthrography for detecting these predynamic and dynamic instability stages. Later in the natural history of carpal instability, static malalignment of the wrist and osteoarthritis will develop, both being associated with significant morbidity and disability. To prevent individual and socio-economic implications, the handsurgeon or orthopedist, as well as the radiologist, is challenged for early and precise diagnosis. (orig.)

  8. Electromagnetic ion cyclotron waves in the plasma depletion layer

    Science.gov (United States)

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

    1993-01-01

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

  9. Princeton Cyclotron QDDD spectrograph system

    International Nuclear Information System (INIS)

    Kouzes, R.T.

    1985-01-01

    A review of experiments involving the Princeton Quadrupole-Dipole-Dipole- Dipole (QDDD) spectrograph is given. The QDDD is a high resolution, large solid angle device which is combined with the azymuthally varying field (AVF) cyclotron. Some reactions involving 3 He beams are discussed

  10. PIXE analysis by baby cyclotron

    International Nuclear Information System (INIS)

    Yoshida, Hyogo; Tanaka, Teruaki; Ito, Takashi; Toda, Yohjiro; Wakasa, Hideichiro

    1988-01-01

    The Japan Steel Works, Ltd. has been supplying a very small sized cyclotron (Baby Cyclotron) to hospitals and research facilities. The cyclotron is designed to produce short-lived radioisotopes for medical use. In the present study, this cyclotron is modified so that it can serve for PIXE analysis. The PIXE (particle induced X-ray emission) technique has the following features: (1) Down to 1 ng of trace material in a sample (mg - μg) can be detected, (2) An analysis run is completed in one to ten minutes, permitting economical analysis for a large number of samples, (3) Several elements can be analyzed simultaneously, with an almost constant sensitivity for a variety of elements ranging from aluminum to heavy metals, (4) Analysis can be performed nondestructively without a chemical process, and (5) The use of microbeam can provide data on the distribution of elements with a resolution of several μm. Software for analysis is developed to allow the modified equipment to perform peak search, background fitting, and identification and determination of peaks. A study is now being conducted to examine the performance of the equipment for PIXE analysis of thin samples. Satisfactory results have been obtained. The analysis time, excluding the background correction, is 5-10 min. (Nogami, K.)

  11. Ion sources for cyclotron applications

    International Nuclear Information System (INIS)

    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

  12. Cyclotron transitions of bound ions

    Science.gov (United States)

    Bezchastnov, Victor G.; Pavlov, George G.

    2017-06-01

    A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

  13. 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.)

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

    International Nuclear Information System (INIS)

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

    1993-02-01

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

  15. Development of cyclotron solid targetry

    International Nuclear Information System (INIS)

    D'Souza, J.; Deans, T.; Cryer, D.; Price, R.

    2004-01-01

    Full text: Western Australia's first medical cyclotron was recently installed in the Department of Medical Technology and Physics at Sir Charles Gairdner Hospital. The cyclotron is routinely used for 18 F production using a liquid target, and now research is being undertaken into solid target bombardment for production of novel isotopes such as 124 I, 64 Cu and 96 Tc. The IBA Cyclone 18/9 has a maximum proton beam energy of 18MeV and maximum beam current of 80μA. A proton beam is generated by the acceleration of H- ions in the evacuated cyclotron (10 -6 bar) which are then stripped of 2 electrons just prior to exiting a target port. Each port has two strippers which are made of 10μm thick carbon with dimensions 12mmxl3mm. Due to their thinness, the strippers are easily ruptured. The Cyclone 18/9 has 8 target ports. In order to fit a target onto the cyclotron when the cyclotron is already evacuated the target is first evacuated to 10 -3 bar by a roughing pump before an isolation valve at the port is opened. This stops any damage that may occur by the flow of air from the target reservoir to the cyclotron eg to the strippers. The first step in the project to develop solid targetry is to build a beam line in order to measure the beam profile. If successful, this design will be improved in order to have a beam line and target holder that are suitable for use in solid target bombardment. A 40cm beam line with an internal diameter of 3.6cm was built to fit onto the IBA Cyclone 18/9. The beam line, made out of aluminium, incorporates a step 5cm from the end at which a target material can be fitted. A cover fits onto the beam line, behind the target in order to maintain vacuum. The cover is held in place by the vacuum within the beam line. At the end of bombardment, the beam line can be isolated from the vacuum of the target and normal air pressure restored. In doing so the cover plate falls open and the target falls into a lead pot, ready for removal from the cyclotron

  16. Simultaneous Propagation of Heat Waves Induced by Sawteeth and Electron-Cyclotron Heating Power Modulation in the Rtp Tokamak

    NARCIS (Netherlands)

    Gorini, G.; Mantica, P.; Hogeweij, G. M. D.; De Luca, F.; Jacchia, A.; Konings, J. A.; Cardozo, N. J. L.; Peters, M.

    1993-01-01

    The incremental electron heat diffusivity chi(inc) is determined in Rijnhuizen Tokamak Project plasmas by measurements of simultaneous heat pulses due to (1) the sawtooth instability and (2) modulated electron cyclotron heating. No systematic difference is observed between the two measured chi(inc)

  17. Neutron radiography with the cyclotron

    International Nuclear Information System (INIS)

    Tazawa, Shuichi; Asada, Yorihisa; Yano, Munehiko; Nakanii, Takehiko.

    1985-01-01

    Neutron radiography is well recognized as a powerful tool in nondestructive testing, but not widely used yet owing to lack of high intense thermal neutron source convenient for practical use. This article presents a new neutron radiograph facility, utilizing a sub-compact cyclotron as neutron source and is equipped with vertical and horizontal irradiation ports. The article describes a series of experiments, we conducted using beams of a variable energy cyclotron at Tohoku University to investigate the characteristics of thermal neutron obtained from 9 Be(p, n) reaction and thermalized by elastic scattering process. The article also describes a computer simulation of neutron moderator to analyze conditions getting maximal thermal neutron flux. Further, some of practical neutron radiograph examinations of aero-space components and museum art objects of classic bronze mirror and an attempt realizing real time imaging technique, are introduced in the article. (author)

  18. 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.

  19. Cyclotron radiation from hot plasmas

    International Nuclear Information System (INIS)

    Pohl, F.; Henning, J.; Duechs, D.

    1975-11-01

    In calculating the energy transport and losses due to cyclotron radiation there are two major requirements: the absorption coefficient has to be known and the proper geometry of the plasma has to be taken into account. In this report Trubnikov's integral formulae for the absorption coefficient have been evaluated numerically and compared with the approximative formulas of previous authors. Deviations by a factor of 2 - 10 in various frequency regimes are not unusual. With these coefficients the rate of change of the energy density due to cyclotron radiation in a plasma as well as the radiation density at a plasma surface are computed for plasma slab and plasma cylinder. Sometimes considerable differences to the results of previons papers can found. Many simple formulae interpolating the numerical results are given in the text, and the FORTRAN computer programs have been reproduced in the appendices. (orig.) [de

  20. Cyclotron production of Cu-61

    Czech Academy of Sciences Publication Activity Database

    Lebeda, Ondřej; Ráliš, Jan; Seifert, Daniel

    2013-01-01

    Roč. 40, 2 Supplement (2013), S323-S323 ISSN 1619-7070. [Annual Congress of the European Association of Nuclear Medicine (EANM). 19.10.2013-23.10.2013, Lyon] R&D Projects: GA TA ČR TA02010797 Institutional support: RVO:61389005 Keywords : cyclotron U-120M * PET * Cu-61 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  1. Status report on the cyclotron

    International Nuclear Information System (INIS)

    Kormany, Z.

    2002-01-01

    Complete text of publication follows. The operation of the cyclotron in 2001 was again concentrated to the usual 9 months; January, July and August were reserved for maintenance and holidays. The overall working time of the accelerator was 4300 hours, the breakdown periods amounted to 66 hours last year. The cyclotron was available for users during 3751 hours, the effectively used beam-on-target time is summarized in Table 1. The total time required for machine setup and beam tuning or spent waiting for the start of an irradiation was 272 hours. The control of the adjustable collimators applied in the beam transport system of the cyclotron was renewed during the winter maintenance period. They have been connected to the programmable logic controllers (PLC) and their new control code frees the operators from the long and slow manual setting process. The successful renewal of the control of this and other subsystems (cyclotron and beam transport power supplies) made lots of adjusting and measuring elements on the original control desk needless. To provide more space for the control PCs and remove all unnecessary devices, the unused part of the control desk has been dismantled. The short beam line used mainly for radiation hardness studies was equipped with a new oil-diffusion vacuum system during the summer maintenance. Its components are also connected to the PLC and the same automatic control has been provided like for the other vacuum stands of- the beam transport system. Another short beam line - basically a mirror image of the first one - has also been installed and successfully tested by trial irradiations. (R.P.)

  2. Commercial compact cyclotrons in the 90's

    International Nuclear Information System (INIS)

    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 we 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. We will also discuss the possibility of systems designed for higher energies and capable of extracted beam currents of up to 2.0 mA. (author)

  3. Commercial compact cyclotrons in the 90's

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. Future cyclotron systems : an industrial perspective

    International Nuclear Information System (INIS)

    Stevenson, N.R.; Dickie, W.J.

    1995-09-01

    The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modem cyclotron-based isotope production facilities. In particular, the change to negative ion acceleration and new high power systems have resulted in dramatic improvements in reliability, increases in capacity, and decreases in personnel radiation dose. As more and more older machines are retired decisions regarding their replacement are made based on several factors including the market's potential and the cyclotron system's abilities. Taking the case of the recently upgraded TR30 cyclotron at TRIUMF/Nordion, we investigate the requirements industrial/medical users are likely to impose on future commercial cyclotron systems and the impact this will have on cyclotron technology by the end of the century. (author)

  6. Future cyclotron systems: An industrial perspective

    International Nuclear Information System (INIS)

    Stevenson, N.R.; Dickie, W.J.

    1995-09-01

    The use of commercial cyclotron systems for the production of radioisotopes continues to grow on a world-wide scale. Improvements in technology have significantly increased the production capabilities of modern cyclotron-based isotope production facilities. In particular, the change to negative ion acceleration and new high power systems have resulted in dramatic improvements in reliability, increases in capacity, and decreases in personnel radiation dose. As more and more older machines are retired, decisions regarding their replacement are made based on several factors including the market's potential and the cyclotron system's abilities. Taking the case of the recently upgraded TR30 cyclotron at TRIUMF/Nordion, the authors investigate the requirements industrial/medical users are likely to impose on future commercial cyclotron systems and the impact this will have on cyclotron technology by the end of the century

  7. Drift Instabilities and Electron Cyclotron Oscillations for Arbitrary Plasma Pressure; Instabilites de Derive et Oscillations Cyclotroniques des Electrons pour des Pressions de Plasma Arbitraires; Drejfovaya neustojchivost' i ehlektronno-tsiklotronnye kolebaniya pri proizvol'nom davlenii plazmy; Inestabilidades de Deriva y Oscilaciones Ciclotronicas de los Electrones en un Plasma de Presion Arbitraria

    Energy Technology Data Exchange (ETDEWEB)

    Krall, N. A.; Pearlstein, L. D. [General Atomic Division, General Dynamics Corporation, San Diego, CA (United States)

    1966-04-15

    Most of the familiar drift instabilities (flute, universal, etc.) were, calculated in the limit {beta} = (plasma pressure)/(magnetic pressure) = 0. In this limit the perturbed electric field is electrostatic, and the Vlasov equation is remarkably simplified. The {beta} limit for validity of the electrostatic approximation depends on the particular mode considered and many present experiments fall outside the range. Two well-known low frequency drift instabilities are examined at arbitrary {beta}; the zero-{beta} regime is determined and stability criteria for larger values of {beta} are derived. In addition, the influence of finite {beta} on radiation at the electron cyclotron harmonics is examined. The finite Larmor radius (R) flute instability driven by mirror type curvature of the magnetic field is considered first. The lowest order's ominously large contribution, inversely proportional to R{sup 2}, cancels to all orders of {beta}. The leading terms are then independent of R, and are. included in the eigenvalue problem; stability criteria are obtained for various ranges of B. Next the universal instability, E = Perturbed = E (exp ik{sub Up-Tack }r{sub Up-Tack })(exp ik{sub II}r{sub II}), in a uniform magnetic field B = B{sub 0}i{sub II} is considered, with field curvature simulated by a fictitious gravity. Here the zero-{beta} limit is dependent upon wavelengths. If {beta} < (electron mass)/(ion mass), or if {beta} <(k{sub II}r{sub p}){sup 2} where r{sub p} = plasma radius and 1/k{sub II} {>=} plasma length, the zero-{beta} limit obtains. Since the instability only exists for (k{sub II}r{sub p}){sup 2} < 0.01, a modest plasma pressure violates the zero-{beta} limit. The eigenvalue for {beta} >(k{sub ll}r{sub p}){sup 2} is calculated and conditions for cusp stabilization as well as mirror destabilization are obtained. The dominant high frequency non-relativistic modes of the stable zero-{beta} plasma are longitudinal waves at electron gyrofrequency harmonics. If

  8. A new cyclotron for biomedical research

    International Nuclear Information System (INIS)

    Wolber, G.

    1988-01-01

    This paper presents the rationale for replacing the old AEG Compact Cyclotron (built in 1969/71) of the Institute for Radiology and Pathophysiology at the German Cancer Research Center by a 30 MeV H - /15 MeV D - cyclotron. A status report is followed by the scientific and technical reasoning as well as budgetary and organizational considerations. In the appendix we tried to explain the function of a cyclotron in a simple and comprehensive manner. (orig.) [de

  9. Advances in superconducting cyclotrons at MSU

    International Nuclear Information System (INIS)

    Blosser, H.; Antaya, T.; Au, R.

    1987-01-01

    Intensive work on superconducting cyclotrons began at MSU in late 1973 (a brief earlier study had occurred in the early 1960's) and continues vigorously at present. One large cyclotron, the ''K500'', has been operating for a number of years, a second, the ''K800'', is nearing completion, the first operating tests of its magnet having occurred at the time of the previous conference, and a third, the ''medical cyclotron'', is now also nearing completion with first operation of its magnet expected just after the present conference. These cyclotrons like other superconducting cyclotrons are all dramatically smaller than comparable room temperature machines; overall weight is typically about 1/20th of that of room temperature cyclotrons of the same energy. This large reduction in the quantities of materials is partially offset by added complexity, but finally, a net overall cost savings of 50 to 70 % typically results; as a consequence the superconducting cyclotron is widely viewed as the cyclotron of the future. The thirteen years of experience at MSU involving three of these cyclotrons, together with much important work at other laboratories, gives a rather clear view of the advantages and disadvantages of various design approaches including by now a rather significant period of long term evaluation. This paper reviews highlights of this program. (author)

  10. 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...... experiments. The observations can be linked to parametric decay of the gyrotron radiation at the second harmonic upper hybrid resonance layer....

  11. Tail anisotropy instability during plasma current rise by lower-hybrid waves in a tokamak

    International Nuclear Information System (INIS)

    Yamagiwa, Mitsuru.

    1986-01-01

    Tail anisotropy instability during lower-hybrid current rise is investigated. Tail formation by lower-hybrid waves is studied by using a Fokker-Planck equation combined with the return field and the rf associated terms. Quasi-linear relaxation of the electron tail distribution under the influence of the plasma waves excited due to the instability is examined. It is found that the instability condition is related to the strength of the parallel diffusion by lower-hybrid waves and the ratio of the electron cyclotron frequency to the electron plasma frequency. The time scale between the instability spikes and the suppression of the instability by electron cyclotron heating are also discussed. (author)

  12. Oblique Alfvén instabilities driven by compensated currents

    Energy Technology Data Exchange (ETDEWEB)

    Malovichko, P. [Main Astronomical Observatory, NASU, Kyiv (Ukraine); Voitenko, Y.; De Keyser, J., E-mail: voitenko@oma.be [Solar-Terrestrial Centre of Excellence, Space Physics Division, Belgian Institute for Space Aeronomy, Ringlaan-3-Avenue Circulaire, B-1180 Brussels (Belgium)

    2014-01-10

    Compensated-current systems created by energetic ion beams are widespread in space and astrophysical plasmas. The well-known examples are foreshock regions in the solar wind and around supernova remnants. We found a new oblique Alfvénic instability driven by compensated currents flowing along the background magnetic field. Because of the vastly different electron and ion gyroradii, oblique Alfvénic perturbations react differently on the currents carried by the hot ion beams and the return electron currents. Ultimately, this difference leads to a non-resonant aperiodic instability at perpendicular wavelengths close to the beam ion gyroradius. The instability growth rate increases with increasing beam current and temperature. In the solar wind upstream of Earth's bow shock, the instability growth time can drop below 10 proton cyclotron periods. Our results suggest that this instability can contribute to the turbulence and ion acceleration in space and astrophysical foreshocks.

  13. Oblique Alfvén instabilities driven by compensated currents

    International Nuclear Information System (INIS)

    Malovichko, P.; Voitenko, Y.; De Keyser, J.

    2014-01-01

    Compensated-current systems created by energetic ion beams are widespread in space and astrophysical plasmas. The well-known examples are foreshock regions in the solar wind and around supernova remnants. We found a new oblique Alfvénic instability driven by compensated currents flowing along the background magnetic field. Because of the vastly different electron and ion gyroradii, oblique Alfvénic perturbations react differently on the currents carried by the hot ion beams and the return electron currents. Ultimately, this difference leads to a non-resonant aperiodic instability at perpendicular wavelengths close to the beam ion gyroradius. The instability growth rate increases with increasing beam current and temperature. In the solar wind upstream of Earth's bow shock, the instability growth time can drop below 10 proton cyclotron periods. Our results suggest that this instability can contribute to the turbulence and ion acceleration in space and astrophysical foreshocks.

  14. Summary on electron cyclotron theory

    International Nuclear Information System (INIS)

    Westerhof, E.

    2003-01-01

    The papers presented within the Theory Sessions of the conference clearly reflect the general trends of the research field. The growing use of Electron Bernstein Waves (EBW) for plasma heating and current drive in overdense plasmas goes hand in hand with an increased theoretical understanding of EBW excitation. While the expanding number of devices with powerful ECRH systems allowing ever more detailed experiments is reflected in the increased detail of modelling and consequent understanding of the experimental results. Apart from these general trends, some more fundamental contributions to the field of electron cyclotron wave propagation are highlighted. (author)

  15. Studies of electron cyclotron emission on text

    International Nuclear Information System (INIS)

    Gandy, R.F.

    1990-07-01

    The Auburn University electron cyclotron emission (ECE) system has made many significant contributions to the TEXT experimental program during the past five years. Contributions include electron temperature information used in the following areas of study: electron cyclotron heating (ECH), pellet injection, and impurity/energy transport. Details of the role which the Auburn ECE system has played will now be discussed

  16. Cyclotrons for the production of radioactive beams

    International Nuclear Information System (INIS)

    Clark, D.J.

    1990-01-01

    This paper describes the characteristics and design choices for modern cyclotrons. Cyclotrons can be used in 3 areas in the radioactive beam field: the production of high energy heavy ion beams for use in fragmentation, the spallation of targets with high energy protons, and the acceleration of radioactive beams from low energy to the MeV/u range. 16 refs., 6 figs

  17. Isochronous cyclotron for thermonuclear reactors driving

    International Nuclear Information System (INIS)

    Alenitskij, Yu.G.

    1998-01-01

    The main requirements to an accelerator as a part of an electronuclear power plant are considered. The range of the parameters of the accelerated proton and deuteron beams, for which the isochronous cyclotron is the most profitable, is proposed. An opportunity of using the cyclotron to drive the research reactors of various types is considered

  18. Trends in cyclotrons for radionuclide production

    International Nuclear Information System (INIS)

    Vera Ruiz, H.; Lambrecht, R.M.

    1999-01-01

    The IAEA recently concluded a worldwide survey of the cyclotrons used for radionuclide production. Most of the institutions responded to the questionnaire. The responses identified technical, utilisation and administrative information for 206 cyclotrons. Compiled data includes the characteristics, performance and popularity of each of the different commercial cyclotrons. Over 20 cyclotrons are scheduled for installation in 1998. The expansion in the number of cyclotron installations during the last decade was driven by the advent of advances in medical imaging instrumentation (namely, positron emission tomography (PET), and more recently by 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons; and recent governmental decisions that permit reimbursement for cyclotron radiopharmaceutical studies by the government or insurance companies. The priorities for the production of clinical, commercial and research radionuclides were identified. The emphasis is on radionuclides used for medical diagnosis with SPET (e.g. 123 I, 201 Tl) and PET (e.g. 11 C, 13 N, 15 O, 18 F) radiopharmaceuticals, and for individualized patient radiation treatment planning (e.g. 64 Cu, 86 Y, 124 I) with PET. There is an emerging trend to advance the cyclotron as an alternative method to nuclear reactors for the production of neutron-rich radionuclides (e.g. 64 Cu, 103 Pd, 186 Re) needed for therapeutic applications. (authors)

  19. Wave fronts of electromagnetic cyclotron harmonic waves

    International Nuclear Information System (INIS)

    Ohnuma, T.; Watanabe, T.

    1982-01-01

    In an inhomogeneous high-density magnetized plasma, the spatial properties of the wave fronts and ray trajectories of electromagnetic ordinary and extraordinary cyclotron harmonic waves are investigated. Those waves which are radiated from a local source are found to have wave fronts which are almost parallel to the magnetic field. Also, the reflective properties of the electromagnetic cyclotron harmonic waves are confirmed

  20. Recent development and progress of IBA cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Kleeven, W., E-mail: Willem.Kleeven@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Abs, M., E-mail: Michel.Abs@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Delvaux, J.L., E-mail: Jean-Luc.Delvaux@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Forton, E., E-mail: Eric.Forton@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Jongen, Y., E-mail: Yves.Jongen@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Medeiros Romao, L., E-mail: Luis.MedeirosRomao@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nactergal, B., E-mail: Benoit.Nactergal@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Nuttens, V., E-mail: Vincent.Nuttens@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Servais, T., E-mail: Thomas.Servais@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Vanderlinden, T., E-mail: Thierry.Vanderlinden@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium); Zaremba, S., E-mail: Simon.Zaremba@iba-group.com [Ion Beam Applications s.a. Chemin du Cyclotron 3, Louvain-la-Neuve (Belgium)

    2011-12-15

    Several cyclotron development projects were recently realized by Ion Beam Applications S.A. (IBA). This contribution presents three of them: (i) the intensity enhancement of the Cyclone 30 cyclotron, a machine mainly used for the production of SPECT isotopes. This project is related with the increased demand for {sup 201}Tl because of the shortage of Mo/Tc generators from nuclear reactors, (ii) development of a new versatile multiple-particle K = 30 isotope-production cyclotron (the Cyclone 30XP) being able to accelerate H{sup -}, D{sup -} and also {alpha}-particles. The {alpha}-beam of this cyclotron will allow the production of new therapeutic isotopes (e.g. {sup 211}At) and (iii) commissioning of the Cyclone 70 cyclotron installed for Arronax in France. This machine is similar to the C30XP but provides higher energy (K = 70) and allows research on new types of medical isotopes.

  1. 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...

  2. Computer design of a compact cyclotron

    International Nuclear Information System (INIS)

    Bing Wang; Huanfeng Hao; Qinggao Yao; Jinquan Zhang; Mingtao Song; Vorozhtsov, S.B.; Smirnov, V.L.; Hongwei Zhao

    2011-01-01

    Here we present results of the computer design of the structural elements of a compact cyclotron by the example of HITFiL cyclotron selected as the driving accelerator that is under construction at the Institute of Modern Physics (Lanzhou, China). In the article a complex approach to modeling of the compact cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics calculations, is described. The existing design data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron are used as a starting point in the simulation. Some of the upgrades of the cyclotron structural elements were proposed, which led to substantial improvement of the beam quality and transmission

  3. Cyclotron-Resonance-Maser Arrays

    International Nuclear Information System (INIS)

    Kesar, A.; Lei, L.; Dikhtyar, V.; Korol, M.; Jerby, E.

    1999-01-01

    The cyclotron-resonance-maser (CRM) array [1] is a radiation source which consists of CRM elements coupled together under a common magnetic field. Each CRM-element employs a low-energy electron-beam which performs a cyclotron interaction with the local electromagnetic wave. These waves can be coupled together among the CRM elements, hence the interaction is coherently synchronized in the entire array. The implementation of the CRM-array approach may alleviate several technological difficulties which impede the development of single-beam gyro-devices. Furthermore, it proposes new features, such as the phased-array antenna incorporated in the CRM-array itself. The CRM-array studies may lead to the development of compact, high-power radiation sources operating at low-voltages. This paper introduces new conceptual schemes of CRM-arrays, and presents the progress in related theoretical and experimental studies in our laboratory. These include a multi-mode analysis of a CRM-array, and a first operation of this device with five carbon-fiber cathodes

  4. Production of radiopharmaceuticals by cyclotrons

    International Nuclear Information System (INIS)

    Schmitz, F.; Van Naemen, J.; Monclus, M.; Van Gansbeke, B.; Kadiata, M.; Ekelmans, D.; Moray, M.; Penninckx, R.; Goldman, S.

    2004-01-01

    Companies specialized in the development and installation of accelerator-based systems dedicated to the medical applications brought on the market cyclotrons well fitted to the requests of the industrial community or universities and so covering every segment of the market. These machines are fully automatic, and need reduced maintenance; they are highly specialized for defined tasks. They can produce high beam intensity and realize dual beam irradiation. Also the prices are reducing considerably. The targets and the automatic system follow the same trend. Unfortunately, the flexibility of these devices for new area of research and development has been dramatically reduced. The growing number of PET cameras has increased the popularity of PET tracers used for nuclear imaging. Consequently, there is a growing demand for these radiopharmaceuticals compounds labeled with short-lived radioisotopes for clinical applications. From a research and development tool in the eighties, PET has now grown up to a clinical tool. Moreover, depending of the social welfare, reimbursement of some PET examinations is granted, which accelerates the trend for an extended use of PET tracers. Regulatory affairs try to establish and standardize the control on these radiopharmaceutical compounds produced in a growing number of local radio pharmacies owning a baby cyclotron. On the other hand, the attention of equipment suppliers was brought in the setting up of a total quality control follow up. These efforts were successively achieved by getting for instance the ISO 9001 certificate

  5. Medical cyclotron basic concepts and its applications

    International Nuclear Information System (INIS)

    Kumar, Rajeev; Sonkawade, R.G.

    2012-01-01

    More than 3000 nuclides are known, of which approximately 2700 are radioactive, and rest are stable. The majority of radionuclides are artificially produced in the reactor and cyclotron. In a cyclotron, Charge particle such as proton, Deuteron, á (Alpha) particle, 3 He particles and so forth are accelerated in circular paths within the Dees under vacuum by means of an electromagnetic field. These accelerated particles can possess few KeV to several BeV of kinetic energy depending on the design of the cyclotron. At our setup we have an 11 MeV dual beam multi target cyclotron which is capable producing 11 C, 13 N, 15 O, 18 F and 2 F radioisotopes and all have been successfully produced and tested in our lab. Earlier cyclotrons were the best source of high-energy beams for nuclear physics experiments; several cyclotrons are still in use for this type of research. Cyclotrons can be used to treat cancer. Ion beams from cyclotrons can be used, as in proton therapy. The positron emitting isotopes are suitable for PET imaging. As discussed we are producing mainly Carbon-11, Nitrogen-13, Oxygen-15, and Fluorine-18: These are positron emitters used in PET for studying brain physiology and pathology, in particular for localizing epileptic focus, and in dementia, psychiatry and neuropharmacology studies. So these are having significant role in diagnosis of Oncological, Neurological and Cardiological disorder. More than ninety percent we are producing 18 F in FDG. 18 F in FDG (Flouro-Deoxy-glucose) has become very important in detection of cancers and the monitoring of progress in their treatment, using PET. Medical cyclotron is complex equipment requiring delicate handling by highly trained personnel. The aim of this article is to highlight few finer aspects of Medical cyclotron operation, including precautions for safety and smooth functioning of this sophisticated equipment. (author)

  6. Off-equatorial current-driven instabilities ahead of approaching dipolarization fronts

    Science.gov (United States)

    Zhang, Xu; Angelopoulos, V.; Pritchett, P. L.; Liu, Jiang

    2017-05-01

    Recent kinetic simulations have revealed that electromagnetic instabilities near the ion gyrofrequency and slightly away from the equatorial plane can be driven by a current parallel to the magnetic field prior to the arrival of dipolarization fronts. Such instabilities are important because of their potential contribution to global electromagnetic energy conversion near dipolarization fronts. Of the several instabilities that may be consistent with such waves, the most notable are the current-driven electromagnetic ion cyclotron instability and the current-driven kink-like instability. To confirm the existence and characteristics of these instabilities, we used observations by two Time History of Events and Macroscale Interactions during Substorms satellites, one near the neutral sheet observing dipolarization fronts and the other at the boundary layer observing precursor waves and currents. We found that such instabilities with monochromatic signatures are rare, but one of the few cases was selected for further study. Two different instabilities, one at about 0.3 Hz and the other at a much lower frequency, 0.02 Hz, were seen in the data from the off-equatorial spacecraft. A parallel current attributed to an electron beam coexisted with the waves. Our instability analysis attributes the higher-frequency instability to a current-driven ion cyclotron instability and the lower frequency instability to a kink-like instability. The current-driven kink-like instability we observed is consistent with the instabilities observed in the simulation. We suggest that the currents needed to excite these low-frequency instabilities are so intense that the associated electron beams are easily thermalized and hence difficult to observe.

  7. The magnetized electron-acoustic instability driven by a warm, field-aligned electron beam

    International Nuclear Information System (INIS)

    Sooklal, A.; Mace, R.L.

    2004-01-01

    The electron-acoustic instability in a magnetized plasma having three electron components, one of which is a field-aligned beam of intermediate temperature, is investigated. When the plasma frequency of the cool electrons exceeds the electron gyrofrequency, the electron-acoustic instability 'bifurcates' at sufficiently large propagation angles with respect to the magnetic field to yield an obliquely propagating, low-frequency electron-acoustic instability and a higher frequency cyclotron-sound instability. Each of these instabilities retains certain wave features of its progenitor, the quasiparallel electron-acoustic instability, but displays also new magnetic qualities through its dependence on the electron gyrofrequency. The obliquely propagating electron-acoustic instability requires a lower threshold beam speed for its excitation than does the cyclotron-sound instability, and for low to intermediate beam speeds has the higher maximum growth rate. When the plasma is sufficiently strongly magnetized that the plasma frequency of the cool electrons is less than the electron gyrofrequency, the only instability in the electron-acoustic frequency range is the strongly magnetized electron-acoustic instability. Its growth rate and real frequency exhibit a monotonic decrease with wave propagation angle and it grows at small to intermediate wave numbers where its parallel phase speed is approximately constant. The relevance of the results to the interpretation of cusp auroral hiss and auroral broadband electrostatic noise is briefly discussed

  8. Two-dimensional Nonlinear Simulations of Temperature-anisotropy Instabilities with a Proton-alpha Drift

    Science.gov (United States)

    Markovskii, S. A.; Chandran, Benjamin D. G.; Vasquez, Bernard J.

    2018-04-01

    We present two-dimensional hybrid simulations of proton-cyclotron and mirror instabilities in a proton-alpha plasma with particle-in-cell ions and a neutralizing electron fluid. The instabilities are driven by the protons with temperature perpendicular to the background magnetic field larger than the parallel temperature. The alpha particles with initially isotropic temperature have a nonzero drift speed with respect to the protons. The minor ions are known to influence the relative effect of the proton-cyclotron and mirror instabilities. In this paper, we show that the mirror mode can dominate the power spectrum at the nonlinear stage even if its linear growth rate is significantly lower than that of the proton-cyclotron mode. The proton-cyclotron instability combined with the alpha-proton drift is a possible cause of the nonzero magnetic helicity observed in the solar wind for fluctuations propagating nearly parallel to the magnetic field. Our simulations generally confirm this concept but reveal a complex helicity spectrum that is not anticipated from the linear theory of the instability.

  9. Electron cyclotron resonance plasma photos

    Energy Technology Data Exchange (ETDEWEB)

    Racz, R.; Palinkas, J. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary); University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary)

    2010-02-15

    In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

  10. Electron cyclotron resonance plasma photos

    International Nuclear Information System (INIS)

    Racz, R.; Palinkas, J.; Biri, S.

    2010-01-01

    In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

  11. Channeling experiments at IPNE Cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, F; Dumitru, M; Ivan, A [Cyclotron Laboratory, Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, R-76900 Bucharest, P.O.Box MG-6, (Romania)

    1992-01-01

    Channeling experiments have been performed at the I.P.N.E Cyclotron using a 3 MeV alpha beam. A slide system cut the beam up to 5 minutes spatial resolution with a maximum 60 nA beam current on the target. The two-axis goniometer, fully computer-controlled, moves the target, a silicon wafer, with 2.5 minute resolution, while an alpha particle sensitive solid state detector, monitors the backscattered particle fluence. In the first stage, channeling appears to be a simple, fast and reliable method for precise monocrystal orientation. A reduction of the host yield by a factor of two allowed impurities and defects to be studied. (Author).

  12. Cyclotron resonance in bilayer graphene.

    Science.gov (United States)

    Henriksen, E A; Jiang, Z; Tung, L-C; Schwartz, M E; Takita, M; Wang, Y-J; Kim, P; Stormer, H L

    2008-02-29

    We present the first measurements of cyclotron resonance of electrons and holes in bilayer graphene. In magnetic fields up to B=18 T, we observe four distinct intraband transitions in both the conduction and valence bands. The transition energies are roughly linear in B between the lowest Landau levels, whereas they follow square root[B] for the higher transitions. This highly unusual behavior represents a change from a parabolic to a linear energy dispersion. The density of states derived from our data generally agrees with the existing lowest order tight binding calculation for bilayer graphene. However, in comparing data to theory, a single set of fitting parameters fails to describe the experimental results.

  13. All-magnetic extraction for cyclotron beam reacceleration

    Science.gov (United States)

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

    1975-07-22

    An isochronous cyclotron can be modified to provide an initial electron stripping stage, a complete acceleration of the stripped ions through the cyclotron to a first energy state, means for returning the ions to an intermediate cyclotron orbit through a second stripping stage, further acceleration of the now higher energy stripped ions through the cyclotron to their final energy, and final extraction of the ions from the cyclotron. (auth)

  14. Dispersion equations for field-aligned cyclotron waves in axisymmetric magnetospheric plasmas

    Directory of Open Access Journals (Sweden)

    N. I. Grishanov

    2006-03-01

    Full Text Available In this paper, we derive the dispersion equations for field-aligned cyclotron waves in two-dimensional (2-D magnetospheric plasmas with anisotropic temperature. Two magnetic field configurations are considered with dipole and circular magnetic field lines. The main contribution of the trapped particles to the transverse dielectric permittivity is estimated by solving the linearized Vlasov equation for their perturbed distribution functions, accounting for the cyclotron and bounce resonances, neglecting the drift effects, and assuming the weak connection of the left-hand and right-hand polarized waves. Both the bi-Maxwellian and bi-Lorentzian distribution functions are considered to model the ring current ions and electrons in the dipole magnetosphere. A numerical code has been developed to analyze the dispersion characteristics of electromagnetic ion-cyclotron waves in an electron-proton magnetospheric plasma with circular magnetic field lines, assuming that the steady-state distribution function of the energetic protons is bi-Maxwellian. As in the uniform magnetic field case, the growth rate of the proton-cyclotron instability (PCI in the 2-D magnetospheric plasmas is defined by the contribution of the energetic ions/protons to the imaginary part of the transverse permittivity elements. We demonstrate that the PCI growth rate in the 2-D axisymmetric plasmasphere can be significantly smaller than that for the straight magnetic field case with the same macroscopic bulk parameters.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-01

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

  16. The thermo magnetic instability in hot viscose plasmas

    Science.gov (United States)

    Haghani, A.; Khosravi, A.; Khesali, A.

    2017-10-01

    Magnetic Rotational Instability (MRI) can not performed well in accretion disks with strong magnetic field. Studies have indicated a new type of instability called thermomagnetic instability (TMI) in systems where Nernst coefficient and gradient temperature were considered. Nernst coefficient would appear if Boltzman equation could be expanded through ω_{Be} (cyclotron frequency). However, the growth rate of this instability was two magnitude orders below MRI growth (Ωk), which could not act the same as MRI. Therefor, a higher growth rate of unstable modes was needed. In this paper, rotating viscid hot plasma with strong magnetic filed was studied. Firstly, a constant alpha viscosity was studied and then a temperature sensitive viscosity. The results showed that the temperature sensitive viscosity would be able to increase the growth rate of TMI modes significantly, hence capable of acting similar to MRI.

  17. Ordinary mode instability associated with thermal ring distribution

    Science.gov (United States)

    Hadi, F.; Yoon, P. H.; Qamar, A.

    2015-02-01

    The purely growing ordinary (O) mode instability driven by excessive parallel temperature anisotropy has recently received renewed attention owing to its potential applicability to the solar wind plasma. Previous studies of O mode instability have assumed either bi-Maxwellian or counter-streaming velocity distributions. For solar wind plasma trapped in magnetic mirror-like geometry such as magnetic clouds or in the vicinity of the Earth's collisionless bow shock environment, however, the velocity distribution function may possess a loss-cone feature. The O-mode instability in such a case may be excited for cyclotron harmonics as well as the purely growing branch. The present paper investigates the O-mode instability for plasmas characterized by the parallel Maxwellian distribution and perpendicular thermal ring velocity distribution in order to understand the general stability characteristics.

  18. Ordinary mode instability associated with thermal ring distribution

    Energy Technology Data Exchange (ETDEWEB)

    Hadi, F.; Qamar, A. [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of)

    2015-02-15

    The purely growing ordinary (O) mode instability driven by excessive parallel temperature anisotropy has recently received renewed attention owing to its potential applicability to the solar wind plasma. Previous studies of O mode instability have assumed either bi-Maxwellian or counter-streaming velocity distributions. For solar wind plasma trapped in magnetic mirror-like geometry such as magnetic clouds or in the vicinity of the Earth's collisionless bow shock environment, however, the velocity distribution function may possess a loss-cone feature. The O-mode instability in such a case may be excited for cyclotron harmonics as well as the purely growing branch. The present paper investigates the O-mode instability for plasmas characterized by the parallel Maxwellian distribution and perpendicular thermal ring velocity distribution in order to understand the general stability characteristics.

  19. 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.

  20. NORTICA - a new code for cyclotron analysis

    International Nuclear Information System (INIS)

    Gorelov, D.; Johnson, D.; Marti, F.

    2001-01-01

    The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state

  1. Development of a Medical Cyclotron Production Facility

    Science.gov (United States)

    Allen, Danny R.

    2003-08-01

    Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes.

  2. Development of a Medical Cyclotron Production Facility

    International Nuclear Information System (INIS)

    Allen, Danny R.

    2003-01-01

    Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short-lived isotopes

  3. 10 GHz ECRIS for Warsaw Cyclotron

    CERN Document Server

    Sudlitz, K

    1999-01-01

    Cusp type, 10 GHz ECRIS has been built and tested earlier. For obtaining intensive beams, more relevant for cyclotron, cusp geometry has been replaced by hexapole. Discharge chamber (stainless steel, 50 mm diameter, 250 mm long) is an extension of a coaxial line, feeding RF (9,6 GHz, up to 200 W) to the plasma. The NdFeB hexapole (0,52 T on the surface) has been used. The axial magnetic field is created by water cooled coils. The axial injection line dedicated to K160 isochronous heavy ion cyclotron has been constructed. The line consists of Glaser lenses, double focusing magnet, solenoid and mirror type inflector. The system provides sufficient transmission of the beam from ECR ion source to the firsts orbits of the cyclotron for m/q ranging from 7 to 2. After successful initial tests which were done in July 1997 the ECRIS serves as an external source for Warsaw Cyclotron.

  4. Application of superconductivity in cyclotron construction

    International Nuclear Information System (INIS)

    Blosser, H.G.

    1982-01-01

    This paper reviews major concepts and design features of the new class of cyclotrons which use superconducting coils to provide main magnet excitation. The discussion begins with a brief historical review tracing the evolution of these ''superconducting'' cyclotrons and the impact of this application of superconductivity in pushing back traditional cyclotron construction limits. This is followed by a review of the principal phenomena which come into play to set new limits on the operating regime, and the nature of these limits, some of which arise from orbit properties and some of which result from construction intricacies in the coil and in the rf system. Conclusions anticipate a future widely encompassing role in the application of superconductivity to cyclotron

  5. Progress report: Variable Energy Cyclotron Centre, Calcutta

    International Nuclear Information System (INIS)

    1999-01-01

    This volume of the progress report brings out the scientific and technical activities of Variable Energy Cyclotron Centre, Calcutta during the year 1999. This includes brief review of the various R and D activities of the Centre and outside users of the cyclotron from the universities and other research institutes. The operational activities of the cyclotron with ECR ion sources, accelerator oriented research activities, activities on detector, target and electronics are reported. The activities of the Computer and Informatics group are described. The status report of the ongoing projects is also provided. The main activities of the superconducting cyclotron project, radioactive ion beam project, heavy ion experimental facility, advanced computational facility, recovery and analysis of helium from hot springs and material science research are described

  6. Electron cyclotron emission imaging in tokamak plasmas

    NARCIS (Netherlands)

    Munsat, T.; Domier, C.W.; Kong, X. Y.; Liang, T. R.; N C Luhmann Jr.,; Tobias, B. J.; Lee, W.; Park, H. K.; Yun, G.; Classen, I.G.J.; Donne, A. J. H.

    2010-01-01

    We discuss the recent history and latest developments of the electron cyclotron emission imaging diagnostic technique, wherein electron temperature is measured in magnetically confined plasmas with two-dimensional spatial resolution. The key enabling technologies for this technique are the

  7. Cyclotron/PET project in Uruguay

    International Nuclear Information System (INIS)

    Engler, H.

    2006-01-01

    The Positron Computed Tomography (PET) is a tri dimensional image technique which shows biochemical information. PET is used in neurology and cardiology diseases. The National Center Cyclotron PET has been found to research, development and health science applications.

  8. Cyclotron method for heavy ion acceleration

    International Nuclear Information System (INIS)

    Gikal, B.N.; Gul'bekyan, G.G.; Kutner, V.B.; Oganesyan, R.Ts.

    1984-01-01

    Studies on heavy ion beams in a wide range of masses (up to uranium) and energies disclose essential potential opportunities for solution of both fundamental scientific and significant economical problems. A cyclotron method for heavy ion acceleration is considered. Development of low and medium energy heavy ion accelerators is revealed. The design of a complex comprising two isochronous cyclotrons which is planned to be constrdcted 1n the JINR is described. The cyclotron complex includes the U-400 and the U-400 M cyclotrons and it is intended for acceleration of both 35-20 MeV/nucleon superheavy ions such as Xe-U and 120 MeV/nucleon light ions. Certain systems of the accelerators are described. Prospects of the U-400 and the U-400 M development are displayed

  9. Progress report on the Milan superconducting cyclotron

    International Nuclear Information System (INIS)

    Acerbi, E.; Alessandria, F.; Baccaglioni, G.; Bellomo, G.; Birattari, C.; Bosotti, A.; Broggi, F.; Cortesi, G.; DeMartinis, C.; Fabrici, E.; Ferrari, A.; Giove, D.; Giussani, A.; Giussani, W.; Michelato, P.; Pagani, C.; Rivoltella, G.; Rossi, L.; Serafini, L.; Sussetto, A.; Torri, V.; Varisco, G.; Cuttone, G.; Raia, G.; Kai, L.

    1988-01-01

    This paper reports on the construction of the K800 superconducting cyclotron at the University of Milan underway since February 1981. The delay in the construction of the new building and a defect of the weldings of the helium vessel have caused a shift in the project schedule of about two years. Currently, the cyclotron magnet and the cryogenic plant have been completed and installed. First operation of the magnet and magnetic field mapping are to begin shortly

  10. 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.

  11. NIRS-Chiba isochronous cyclotron 1975

    International Nuclear Information System (INIS)

    Ogawa, H.; Kumamoto, Y.; Yamada, T.; Hiramoto, T.

    1976-02-01

    The cyclotron facility installed according to the recommendation of the Atomic Energy Committee of Japan is used for neutron therapy and production of short-lived radioisotopes. Construction on the facility was started in the autumn of 1972, and completed in March 1974. Described are the following: beam transport and the experimental hall, machine research and improvement, machine time sharing and the particles and energies, characteristics of the cyclotron, and facility personnel. (auth.)

  12. Initial operation of the cyclotron CYTRACK

    International Nuclear Information System (INIS)

    Denisov, Yu.N.; Dolya, S.N.; Kalinichenko, V.V.; Karamysheva, G.A.; Kostromin, S.A.; Fedorenko, S.B.

    2005-01-01

    The industrial cyclotron CYTRACK is dedicated to produce the track membranes. It is the basic instrument for the industry of membrane products to be consumed in medicine, biotechnology, pharmacology, microelectronics and many other industries. Cyclotron CYTRACK started working in August 2002. Argon ions were accelerated to the project energy - 2.4 MeV/nucleon, the extracted beam intensity was about 200 nA, the extraction efficiency totaled ∼50%

  13. Cyclotron beam dynamic simulations in MATLAB

    International Nuclear Information System (INIS)

    Karamysheva, G.A.; Karamyshev, O.V.; Lepkina, O.E.

    2008-01-01

    MATLAB is useful for beam dynamic simulations in cyclotrons. Programming in an easy-to-use environment permits creation of models in a short space of time. Advanced graphical tools of MATLAB give good visualization features to created models. The beam dynamic modeling results with an example of two different cyclotron designs are presented. Programming with MATLAB opens wide possibilities of the development of the complex program, able to perform complete block of calculations for the design of the accelerators

  14. Effect of an external alternating electric field non-monochromaticity on parametric excitation of surface ion cyclotron X-modes

    International Nuclear Information System (INIS)

    Girka, V O; Puzyrkov, S Yu; Shpagina, V O; Shpagina, L O

    2012-01-01

    The application of an external alternating electric field in the range of ion cyclotron frequencies is a well-known method for the excitation of surface electromagnetic waves. The present paper is devoted to the development of a kinetic theory of parametric excitation of these eigenwaves propagating across an external steady magnetic field along the plasma boundary at the second harmonic of the ion cyclotron frequency. Unlike previous papers on this subject, parametric excitation of surface ion cyclotron X-modes is studied here under the condition of non-monochromaticity of an external alternating electric field. Non-monochromaticity of the external alternating electric field is modeled by the superposition of two uniform and monochromatic electric fields with different amplitudes and frequencies. The nonlinear boundary condition is formulated for a tangential magnetic field of the studied surface waves. An infinite set of equations for the harmonics of a tangential electric field is solved using the approximation of the wave packet consisting of the main harmonic and two nearest satellite harmonics. Two different regimes of instability have been considered. If one of the applied generators has an operation frequency that is close to the ion cyclotron frequency, then changing the amplitude of the second generator allows one to enhance the growth rate of the parametric instability or to diminish it. But if the operation frequencies of the both generators are not close to the ion cyclotron frequency, then changing the amplitudes of their fields allows one to decrease the growth rate of the instability and even to suppress its development. The problem is studied both analytically and numerically.

  15. Ion heating at the disruptive instability in the LT-3 Tokamak

    International Nuclear Information System (INIS)

    Bell, M.G.; Hutchinson, I.H.

    1976-01-01

    Measurements of the ion temperature and the toroidal current density and electric field during the disruptive instability in LT-3 are presented. Rapid ion heating and strong current inhibition have been observed. Fluctuation measurements suggest that these effects may be attributable to the excitation of ion cyclotron drift waves in the plasma

  16. Ion-cyclotron-resonance- and Fourier-transform-ion-cyclotron-resonance spectroscopy: technology and application

    International Nuclear Information System (INIS)

    Luederwald, I.

    1977-01-01

    Instrumentation and technology of Ion-Cyclotron-Resonance and Fourier-Transform-Ion-Cyclotron-Resonance Spectroscopy are described. The method can be applied to studies of ion/molecule reactions in gas phase, to obtain thermodynamic data as gas phase acidity or basicity, proton and electron affinity, and to establish reaction mechanisms and ion structures. (orig.) [de

  17. A national medical cyclotron facility: report to the Minister of Health by the Medical Cyclotron Committee

    International Nuclear Information System (INIS)

    1985-01-01

    Research and training in nuclear medicine in Australia are both limited by the lack of a medical cyclotron facility. The Committee recommends the establishment of a national medical cyclotron to provide a supply of short-lived radioisotopes for research in relevant fields of medicine, and for diagnostic use in nuclear medicine

  18. 57 Co produced in cyclotron

    International Nuclear Information System (INIS)

    Landini, Liliane; Osso Junior, Joao Alberto

    2000-01-01

    The Cyclotron CV-28 of IPEN-CNEN/SP is a particle accelerator, used mainly in the radioisotope production, applied in 'in vivo' diagnosis in nuclear medicine. Some of them are employed in the calibration of Diagnosis equipment, such as gamma and X-rays detectors. Co-57 is an example of this application. A natural nickel foil was used as target and irradiated with proton beams of 24 MeV energy. The radioactivity analysis of the irradiated target was performed by Gamma Spectroscopy with a HPGe detector. A 259,74MBq (7,02 mCi) Co-57 source was prepared, 67 days after the last bombardment, with impurity levels of 1.13% for Co-56 and 1.29% for Co-58. The thick target yields for Co-57 and for the main radionuclidic impurities were measured, after the chemical separation of the irradiated target, extrapolated to the last EOB: 1.076 MBq (29.09 mCi)/mA.h, 0.012 MBq (0.33 mCi)/mA.h and 0.014 MBq (0.37 mCi)/mA.h, for Co-57, Co-56 and Co-58, respectively. (author)

  19. Electron cyclotron heating of plasmas

    International Nuclear Information System (INIS)

    Guest, Gareth

    2009-01-01

    As nuclear fusion becomes an increasingly important potential energy source in these times of global oil and energy crises, the development of technologies that can lead to the realization of this virtually inexhaustible source of energy takes on ever greater urgency. Over the past decade electron cyclotron heating has undergone a significant maturation and has emerged as an essential component of the major approaches to achieving controlled nuclear fusion. The gyrotron, first developed in the Soviet Union, has made it possible to employ ECH in large tokamak and stellarator fusion devices by providing megawatts of microwave power at frequencies above 100 GHz. A contemporary VGT-8110 gyrotron, for example, shown here with Kevin Felch and Pat Cahalan of Communications and Power Industries, is capable of delivering 10 second pulses of 1 MW of power at 110 GHz. The present monograph addresses the ECH physics critical to the international fusion reactor experiment, ITER, but also presents the fundamentals of ECH that are essential to its successful implementation in applications that range from active experiments in planetary magnetospheres to commercial plasma sources for the manufacture of computer chips. The book seeks to convey the physics of ECH in an orderly and coherent fashion to a professional audience by presenting the basic theoretical foundations and then using the theory to interpret a number of established experimental results. Exercises are included to aid the reader in making the theory more concrete. (orig.)

  20. Nonlinear phenomena at cyclotron resonance

    International Nuclear Information System (INIS)

    Subbarao, D.; Uma, R.

    1986-01-01

    Finite amplitude electromagnetic waves in a magnetoplasma which typically occur in situations as in present day wave heating, current drives and other schemes in magnetically confined fusion systems, can show qualitatively different absorption and emission characteristics around resonant frequencies of the plasma because of anharmonicity. Linear wave plasma coupling as well as weak nonlinear effects such as parametric instabilities generally overlook this important effect even though the thresholds for the two phenomena as shown here are comparable. Though the effects described here are relevant to a host of nonlinear resonance effects in fusion plasmas, the authors mainly limit themselves to ECRH

  1. Electron-cyclotron maser emission during flares: emission in various modes and temporal variations

    International Nuclear Information System (INIS)

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

    1986-01-01

    Absorption of radiation at the electron-cyclotron frequency, OMEGA sub e, generated by the electron-cyclotron maser instability was proposed as a possible mechanism for transporting energy and heating of the corona during flares. Radiation from the same instability but at harmonics of OMEGA sub e is believed to be the source of solar microwave spike bursts. The actual mode and frequency of the dominant emission from the maser instability is shown to be dependent on: (1) the plasma temperature, (2) the form of the energetic electron distribution, and (3) on the ratio of the plasma frequency omega sub p to OMEGA sub e. As a result, the emission along a flux tube can vary, with emission at harmonics being favored in regions where omega sub p/OMEGA sub e approx. equal to or greater than 1. Changes in the plasma density and temperature in the source region associated with the flare can also cause the characteristics of the emission to change in time

  2. Anisotropic gravitational instability

    International Nuclear Information System (INIS)

    Polyachenko, V.L.; Fridman, A.M.

    1988-01-01

    Exact solutions of stability problems are obtained for two anisotropic gravitational systems of different geometries - a layer of finite thickness at rest and a rotating cylinder of finite radius. It is shown that the anisotropic gravitational instability which develops in both cases is of Jeans type. However, in contrast to the classical aperiodic Jeans instability, this instability is oscillatory. The physics of the anisotropic gravitational instability is investigated. It is shown that in a gravitating layer this instability is due, in particular, to excitation of previously unknown interchange-Jeans modes. In the cylinder, the oscillatory Jeans instability is associated with excitation of a rotational branch, this also being responsible for the beam gravitational instability. This is the reason why this instability and the anisotropic gravitational instability have so much in common

  3. Neutron radiography by using JSW baby cyclotron

    International Nuclear Information System (INIS)

    Toda, Yojiro

    1995-01-01

    At present, JSW baby cyclotrons are mostly used for the production of the radioisotopes for medical use. The attempt to use this baby cyclotron for neutron radiography began already in 1981. The feasibility of the neutron radiography for the explosives in metallic cases which are used for H1 rockets was investigated. In 1983, it was shown that the neutron radiography by using the baby cyclotron in Muroran Works, Japan Steel Works, Ltd. was able to be carried out as a routine work. Since then, the nondestructive inspection by neutron radiography has been performed for rocket pyrotechnic articles, and contributed to heighten their reliability. Further, the radiography by using fast neutrons was developed and put to practical use for recent large H2 rockets. The JSW baby cyclotron BC 168 which has been used for neutron radiography can accelerate 16 MeV protons or 8 MeV deuterons up to 50 μA. The principle of thermal neutron radiography is the generation of fast neutrons by irradiating a Be target with the proton beam accelerated by a baby cyclotron, the moderation of the fast neutrons, the formation of the thermal neutron flux of uniform distribution with a collimator, the thermal neutron flux hitting the Gd plate in a film cassette through an object, and the exposure of an X-ray film to electrons from the Gd plate. Fast neutron radiography apparatus, and commercial neutron radiography are described. (K.I.)

  4. 83-inch cyclotron research program. Final report

    International Nuclear Information System (INIS)

    Parkinson, W.C.

    1983-07-01

    In June of 1960 the US Atomic Energy Commission authorized the construction of a modern variable energy cyclotron facility at The University of Michigan to be used for research in nuclear spectroscopy. The Legislature of the State of Michigan made available funds for construction of a building to house the 83-inch cyclotron and auxiliary equipment as well as the University's remodeled 42-inch cyclotron. The research program centered around the 83-inch cyclotron was funded by the AEC and its successors, the Energy Research and Development Administration (ERDA) and the Department of Energy (DOE), from September 1964 through March 1977. The program represented a continuation of the research effort using the 42-inch cyclotron facility which had been supported continuously by the AEC since February 1950. This final report to DOE briefly describes the research facility, the research program, and highlights the principal accomplishments of the effort. It begins with a historical note to place this effort within the context of nuclear physics research in the Department of Physics of the University of Michigan

  5. Manufacturing on the radiopharmaceuticals produced by cyclotron

    International Nuclear Information System (INIS)

    Ueda, Nobuo

    1994-01-01

    Radiopharmaceutical (RP) produced by cyclotrons are widely used for the in vivo diagnosis of various diseases such as cancer, cerebral vascular disorders and cardiac diseases. The nuclides used as RPs and their nuclear reactions, and the quantity of RPs supplied in Japan in the last five years are shown. These RPs are delivered to about 1,100 hospitals in Japan. Thallium-201 and iodine-123 showed very high growth rate. Recently, two new I-123 RPs, BMIPP and MIBG which are heart-imaging agents, have been supplied. It suggests that the quantity of I-123 will increase much more in future. The image diagnostic method using RPs is called in vivo nuclear medicine, and has become the indispensable means for medical institutions together with X-ray CT, nuclear magnetic resonance imaging and ultrasonic diagnosis. The RPs for in vivo diagnosis generally used at present are classified into those labeled with the RIs produced with cyclotrons and those labeled with Tc-99m formed by the decay of Mo-99. The quantity being used is overwhelmingly more in the latter, but the former shows the tendency of growth. The commercial production of cyclotron RIs for medical use, the chemical forms and the diagnostic purposes of the RPs using cyclotron RIs, and the state of use of the cyclotron-produced RPs are reported. (K.I.)

  6. Low energy cyclotron for radiocarbon dating

    International Nuclear Information System (INIS)

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14 C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14 C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14 C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

  7. Recycling and recommissioning a used biomedical cyclotron

    International Nuclear Information System (INIS)

    Carroll, L.R.; Ramsey, F.; Armbruster, J.; Montenero, M.

    2001-01-01

    Biomedical Cyclotrons have a very long life, but there eventually comes a time when any piece of equipment has to be retired from service. From time to time, we have the opportunity to help find new homes for used cyclotrons which, with relatively modest overhaul and refurbishment, can have many additional years of productive service, and thus represent a very valuable asset. The reasons for retiring a cyclotron vary, of course, but in our experience it is often due to an institution's changing priorities or changing needs, rather than the due to any fundamental age-related deficiency in the cyclotron itself. In this paper we will report on the relocation and successful restoration of a used TCC CP-42 cyclotron, which was moved from M.D. Anderson Hospital in Houston to Denton, Texas in early 1998, where it is presently being used for R and D and commercial production of biomedical isotopes. Ownership of the machine has been transferred to the University of North Texas; facility, manpower, and operational resources are provided by International Isotopes, Inc

  8. Superconducting cyclotron magnet coil short

    International Nuclear Information System (INIS)

    Mallory, M.L.; Blosser, H.G.; Clark, D.J.; Launer, H.; Lawton, D.; Miller, P.; Resmini, F.

    1982-01-01

    In February 1981, a short circuit appeared in the superconducting coil of the K500 cyclotron. The short is resistive in character and therefore has no effect on steady state operation of the magnet. The resistance of the short varies, sometimes being below threshold of detection as a heat load on the cooling system and sometimes being significant. The resistance under certain conditions shows approximately cyclic phenomena with time constants in the range of seconds and other approximately cyclic phenomena which correlate with gross operating parameters of the magnet (shifting current from one coil to another at high field and lowering and raising the liquid helium level). A number of diagnostic studies of the short have been made, using 1) an array of flux sensing loops to sense the magnetic effect of the short, 2) voltage comparisons between upper and lower sections of the coil, 3) comparisons of forces in the nine member coil support system and 4) the effect of the short on the thermal charactersitics of the coil. Insulation failure or a metal chip shorting out turns have been explored in some detail but a convincing determination of the exact cause of the short may never be available, (even the extreme step of unwinding the coil having a significant probability that an imperfection with the observed characteristics would pass unnoticed). Analysis of the characteristics of the short indicated that the most serious consequence would be failure of the coils mechanical support system in the event that the magnet was quickly discharged, as in a dump or quench. To deal with this hazard, the support system has been modified by installing solid supports which prevent the coil from moving by an amount sufficient to damage the support system. We have also reexamined the data and calculations used in the original coil design and have made some additional measurements of the properties of the materials (yield strength, friction coefficient, Young's modulus) used in the

  9. Low-frequency instabilities of a warm plasma in a magnetic field

    International Nuclear Information System (INIS)

    Smith, D.F.; Hollweg, J.V.

    1977-01-01

    The marginal stability of a plasma carrying current along the static magnetic field with isotropic Maxwellian ions and isotropic Maxwellian electrons drifting relative to the ions is investigated. The complete electromagnetic dispersion relation is studied using numerical techniques; the electron sums are restricted to three terms which limits the analysis to frequencies much less than the electron gyro-frequency, but includes frequencies somewhat above the ion gyro-frequency. A 'kink-like' instability and an instability of the Alfven mode are found to have the lowest threshold drift velocities in most cases. In fact the threshold drift for the kink-like instability can be significantly less than the ion thermal speed. Electrostatic and electromagnetic ion-cyclotron instabilities are also found as well as the electro-static ion-acoustic instability. No instability of the fast magnetosonic mode was found. The stability analysis provides only threshold drift velocities and gives no information about growth rates. (author)

  10. Radiation shielding and health physics instrumentation for PET medical cyclotrons

    International Nuclear Information System (INIS)

    Mukherjee, B.

    2002-01-01

    Full text: Modern Medical Cyclotrons produce a variety of short-lived positron emitting PET radioisotopes, and as a result are the source of intense neutron and gamma radiations. Since such cyclotrons are housed within hospitals or medical clinics, there is significant potential for un-intentional exposure to staff or patients in proximity to cyclotron facilities. Consequently, the radiological hazards associated with Cyclotrons provide the impetus for an effective radiological shielding and continuous monitoring of various radiation levels in the cyclotron environment. Management of radiological hazards is of paramount importance for the safe operation of a Medical Cyclotron facility. This work summarised the methods of shielding calculations for a compact hospital based Medical Cyclotron currently operating in Canada, USA and Australia. The design principle and operational history of a real-time health physics monitoring system (Watchdog) operating at a large multi-energy Medical Cyclotron is also highlighted

  11. Statistical fluctuations in cooperative cyclotron radiation

    Science.gov (United States)

    Anishchenko, S. V.; Baryshevsky, V. G.

    2018-01-01

    Shot noise is the cause of statistical fluctuations in cooperative cyclotron radiation generated by an ensemble of electrons oscillating in magnetic field. Autophasing time - the time required for the cooperative cyclotron radiation power to peak - is the critical parameter characterizing the dynamics of electron-oscillators interacting via the radiation field. It is shown that premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function for which the analytic expression is obtained. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1 / lnNe) to square-root (δT ∼ 1 /√{Ne }). A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative cyclotron radiation.

  12. Decommissioning analyzis of a university cyclotron

    International Nuclear Information System (INIS)

    Eggermont, G.X.; Buls, N.; Hermanne, A.

    1996-01-01

    In the widespread use of some medical nuclear facilities, such as cyclotrons for isotope production, Life cycle analyzis, including decommissioning, was not taken into account. The structural materials of an accelerator and the concrete shielding of the bunker are activated by neutrons. This could yield a considerable volume of nuclear waste and needs radiation protection concern for occupational workers and the environment during some decennia. At the university of Brussels (WB) a prospective radiation protection and waste analyzis is being made for the later decommissioning of their cyclotron. Only few similar studies have been published. In Belgium future nuclear dismantling operations will be submitted to a radiation protection authorization procedure. Meanwhile the nuclear waste authorities insist on dismantling planning, including financial provisioning. An optimization exercise was made at the VUB-cyclotron, taking into account international trends to clearance levels for low level nuclear waste. Conceptual prevention opportunities e.g. selective material choice could be identified for future accelerator constructions. (author)

  13. Scientific instruments, scientific progress and the cyclotron

    International Nuclear Information System (INIS)

    Baird, David; Faust, Thomas

    1990-01-01

    Philosophers speak of science in terms of theory and experiment, yet when they speak of the progress of scientific knowledge they speak in terms of theory alone. In this article it is claimed that scientific knowledge consists of, among other things, scientific instruments and instrumental techniques and not simply of some kind of justified beliefs. It is argued that one aspect of scientific progress can be characterized relatively straightforwardly - the accumulation of new scientific instruments. The development of the cyclotron is taken to illustrate this point. Eight different activities which promoted the successful completion of the cyclotron are recognised. The importance is in the machine rather than the experiments which could be run on it and the focus is on how the cyclotron came into being, not how it was subsequently used. The completed instrument is seen as a useful unit of scientific progress in its own right. (UK)

  14. Pick-Up Ion Instabilities at Planetary Magnetospheres

    Science.gov (United States)

    Strangeway, Robert J.; Sharber, James (Technical Monitor)

    2001-01-01

    This effort involved the analysis of low frequency waves as observed by the Galileo spacecraft near the Galilean moon, Io. Io is a significant source of material, especially SO2, and various products of dissociation, and further these atoms and molecules are readily ionized. The initial velocity of the ions is essentially that of the neutral species, i.e., the Keplerian velocity. The plasma, on the other hand is co-rotating, and there is a differential flow of the order 57 km/s between the plasma and the neutral particles. Thus pick-up ion instabilities are Rely to occur within the Jovian magnetosphere. Indeed, magnetometer observations from the Galileo spacecraft clearly show ion cyclotron waves that have been identified with a large variety of plasma species, such as O+, S++ (which has the same gyro-frequency as O+), S+, and SO2+. Typically, however, the dominant frequency is near the SO2+ gyro-frequency. The research effort was originally planned to be a team effort between Robert J. Strangeway as the Principal Investigator, and Debbie Huddleston, who was an Assistant Research Geophysicist at UCLA. Unfortunately, Dr. Huddleston took a position within Industry. The effort was therefore descoped, and Dr. Strangeway instead pursued a collaboration with Dr. Xochitl Blanco-Cano, of the Instituto de Geofisica, Universidad Nacional Autonoma de Mexico. This has proved to be a productive collaboration, with several papers and publications arising out of the effort. The magnetic field oscillations near lo generally fall into two types: ion cyclotron waves, with frequencies near an ion gyro-frequency, and lower frequency mirror-mode waves. The ion cyclotron waves are mainly transverse, and frequently propagate along the ambient magnetic field. The mirror-mode waves are compressional waves, and they have essentially zero frequency in the plasma rest frame. One of the purposes of our investigation is to understand what controls the types of wave modes that occur, since both

  15. Compact dispersion relations for parametric instabilities of electromagnetic waves in magnetized plasmas

    International Nuclear Information System (INIS)

    Cohen, B.I.

    1987-01-01

    The existence of compact dispersion relations for parametric instabilities of coherent electromagnetic waves in magnetized plasmas is addressed here. In general, comprehensive dispersion relations for parametric instabilities in unmagnetized plasmas become more complicated in the presence of an applied time-independent magnetic field. This is demonstrated with a fluid perturbation theory. A compact dispersion relation for parametric instabilities in unmagnetized plasma is heuristically extended here to the case of a magnetized plasma. This dispersion relation gives the correct results in a variety of circumstances of interest in considering electron cyclotron heating applications

  16. Curvature-driven instabilities in a hot-electron plasma: radial analysis

    International Nuclear Information System (INIS)

    Berk, H.L.; Van Dam, J.W.; Rosenbluth, M.N.; Spong, D.A.

    1981-12-01

    The theory of unfavorable curvature-driven instabilities is developed for a plasma interacting with a hot electron ring whose drift frequencies are larger than the growth rates predicted from conventional magnetohydrodynamic theory. A z-pinch model is used to emphasize the radial structure of the problem. Stability criteria are obtained for the five possible modes of instability: the conventional hot electron interchange, a high-frequency hot electron interchange (at frequencies larger than the ion cyclotron frequency), a compressional instability, a background pressure-driven interchange, and an interacting pressure-driven interchange

  17. Radiation exposure to workers at cyclotron facilities

    International Nuclear Information System (INIS)

    Ribeiro, M.S.; Sanches, M.P.; Sanchez, A.S.; Rodrigues, D.L.

    2001-01-01

    Radiopharmaceuticals quickly furnish the information doctors need to establish a precise diagnosis of the patient's condition, and therefore to prescribe the most effective therapy. In cancerology, F18-FDG, the most widely used PET imaging tracer, excels in the early detection of cancer tumors, even very tiny ones, which it locates and clearly distinguishes from healthy surrounding tissues. IPEN-CNEN/SP has two cyclotron accelerators used mainly for radioisotope production to be utilized in nuclear medicine for diagnosis and therapy. The first is a CV-28 cyclotron, variable energy that came into operation in 1982, which was used to produce F18-FDG and Iodine 123 up to 1998. The second, a Cyclone 30 cyclotron, 30 MeV, commenced operation in 1998 for certification purpose, and due to increase demand for radiopharmaceuticals in Brazil, started F18-FDG production in 1999. Cyclotron Laboratory will be a reference Research and Developing Center in our country and will help the Brazilian and Latin-American community. It is necessary to have an adequate database to allow regular follow up and analysis of the individual dose distributions for each group involved in the cyclotron activities. These databases are also important means to assess the effectiveness of efforts in order to maintain doses ALARA and reduce inequalities. The official individual occupational dosimetry is provided by certified Laboratory of Thermoluminescent Dosimetry at IPEN-CNEN/SP. This paper describes the occupational doses distribution in Laboratory of Cyclotrons at IPEN-CNEN/SP from January, 1998 to July, 2000 and propose improvements for the future. (author)

  18. Knowledge based operation assist system for JAERI AVF cyclotron

    International Nuclear Information System (INIS)

    Agematsu, T.; Okumura, S.; Yokota, W.; Arakawa, K.; Murakami, T.; Okamura, T.

    1992-01-01

    We have developed two operation assist systems for easy and rapid operation of the JAERI AVF cyclotron. One is a knowledge based expert system guiding the sequence of parameter adjustment to inexperienced cyclotron operators. The other is a real-time simulation of the beam trajectories which are calculated from actual operating parameters. It graphically indicates feasible setting range of parameters that satisfies the acceptance of the cyclotron. These systems provide a human interface to adjust the parameters of the cyclotron. (author)

  19. Commissioning of cryogen delivery system for superconducting cyclotron magnet

    International Nuclear Information System (INIS)

    Pal, G.; Nandi, C.; Bhattacharyya, T.K.; Chaudhuri, J.; Bhandari, R.K.

    2005-01-01

    A K-500 superconducting cyclotron is being constructed at VECC Kolkata. The cryogen delivery system distributes liquid helium and liquid nitrogen to the superconducting cyclotron. Liquid helium is required to cool the cyclotron magnet and cryopanels. Liquid nitrogen is used to reduce the capacity of the helium liquefier. This paper describes the system, the current status and the commissioning experiences of cryogen delivery system for cyclotron magnet. (author)

  20. ECR ion source for variable energy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Bose, D K; Taki, G S; Nabhiraj, P Y; Pal, G; Dasgupta, B; Mallik, C; Das, S K; Bandopadhaya, D K; Bhandari, R K [Variable Energy Cyclotron Centre, Calcutta (India)

    1995-09-01

    Some performance characteristics of 6.4 GHz two stage ECR ion source which was under development at this centre is presented. The present ion source will facilitate acceleration of light heavy ions with the existing k=130 variable energy cyclotron. Multiply charged heavy ion (MCHI) beam from the source will also be utilized for atomic physics studies. Oxygen beam has already been used for ion implantation studies. The external injection system under development is nearing completion. Heavy ion beam from cyclotron is expected by end of 1995. (author).

  1. Cyclotron Lines in Accreting Neutron Star Spectra

    Science.gov (United States)

    Wilms, Jörn; Schönherr, Gabriele; Schmid, Julia; Dauser, Thomas; Kreykenbohm, Ingo

    2009-05-01

    Cyclotron lines are formed through transitions of electrons between discrete Landau levels in the accretion columns of accreting neutron stars with strong (1012 G) magnetic fields. We summarize recent results on the formation of the spectral continuum of such systems, describe recent advances in the modeling of the lines based on a modification of the commonly used Monte Carlo approach, and discuss new results on the dependence of the measured cyclotron line energy from the luminosity of transient neutron star systems. Finally, we show that Simbol-X will be ideally suited to build and improve the observational database of accreting and strongly magnetized neutron stars.

  2. Instabilities in inhomogeneous plasma

    International Nuclear Information System (INIS)

    Mikhailovsky, A.B.

    1983-01-01

    The plasma inhomogeneity across the magnetic field causes a wide class of instabilities which are called instabilities of an inhomogeneous plasma or gradient instabilities. The instabilities that can be studied in the approximation of a magnetic field with parallel straight field lines are treated first, followed by a discussion of the influence of shear on these instabilities. The instabilities of a weakly inhomogeneous plasma with the Maxwellian velocity distribution of particles caused by the density and temperature gradients are often called drift instabilities, and the corresponding types of perturbations are the drift waves. An elementary theory of drift instabilities is presented, based on the simplest equations of motion of particles in the field of low-frequency and long-wavelength perturbations. Following that is a more complete theory of inhomogeneous collisionless plasma instabilities which uses the permittivity tensor and, in the case of electrostatic perturbations, the scalar of permittivity. The results are used to study the instabilities of a strongly inhomogeneous plasma. The instabilities of a plasma in crossed fields are discussed and the electromagnetic instabilities of plasma with finite and high pressure are described. (Auth.)

  3. 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) bea...

  4. Building on TR-24 success. Advanced Cyclotron Systems Inc. launches a new cyclotron model

    International Nuclear Information System (INIS)

    Russell Watt; William Gyles; Alexander Zyuzin

    2015-01-01

    ACSI is designing a new 30 MeV cyclotron based on the TR-24. While minimizing changes from the proven TR-24, including maintaining the same outer dimensions, the energy of the cyclotron will be increased to 30 MeV, which will make it the most compact, non-superconducting, 30 MeV cyclotron design to date. Maximum beam current will match the TR-24 at 1 mA. With the size and footprint of a typical low energy PET cyclotron, this system will offer users a cost effective solution for a diversified facility capable of producing a wide spectrum of PET and SPECT radioisotopes for research and commercial distribution. (author)

  5. 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.

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

    Science.gov (United States)

    Thorne, Richard M.; Horne, Richard B.

    1994-01-01

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

  7. Identification of minority ion cyclotron emission during radio frequency heating in the JET tokamak

    International Nuclear Information System (INIS)

    Cottrell, G.A.

    1999-11-01

    First measurements and identification of Minority Ion Cyclotron Emission (MICE) during ICRF (H)D minority heating in the JET tokamak are presented. An inner wall radiofrequency (rf) probe shows the new single MICE spectral line, downshifted from the heating, frequency and appearing ∼ 400 ms after the ICRH switch-on. The line is narrow (Δω / ω) ∼ 0.04), characterised by the ion cyclotron frequency of minority protons in the outer edge mid-plane plasma and is observed irrespective of whether single or multi-frequency ICRH is applied. Threshold conditions for MICE are: coupled RF power to the plasma P rf ≥ 4.5 MW; total fast ion energy content W fast ≥ 0.6 MJ. At the time of the rapid switch-on of MICE, the measured power loss from the energetic minority ions is ∼ 0.1 ± 0.1 MW, constituting rf . The observations are consistent with the classical evolution and population of the plasma edge with ∼ 3 MeV ICRH protons on orbits near the outboard limiters. Particle loss and energy filtering contribute to a local non-Maxwellian energetic ion distribution which is susceptible to ion cyclotron instability

  8. Tokamak startup with electron cyclotron heating

    International Nuclear Information System (INIS)

    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

  9. Passive cyclotron current drive for fusion plasmas

    International Nuclear Information System (INIS)

    Kernbichler, W.

    1995-01-01

    The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2 nd -kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

  10. Radioisotope production with a medical cyclotron

    International Nuclear Information System (INIS)

    Silvester, D.J.

    1974-01-01

    The cyclotron of Hammersmith hospital in England was completed and started the operation in 1955. The feature is in its design operable at high beam current, reaching 500μA in internal beam and 300μA in external beam. In 1960's, twelve nuclides of radioactive pharmaceuticals were produced with the cyclotron. C-11, N-13 and O-15 have been used in the form of radioactive gases such as CO or H 2 O to test lung functions. F-18 has been used for bone scanning. K-43 is employed in the research of electrolyte balancing together with Na-24 and Br-77. Fe-52 is utilized in iron ion researches as a tracer. Cs-129 is highly evaluated as an isotope for imaging cardiac clogging part. Radioisotopes must be much more used in the examination of in vivo metabolic function. For this purpose, peculiarly labelled compounds should be further developed. It is welcome that the persons paying attention to the medical prospect of cyclotrons are increasing. The author hopes to continue his endeavour to find new products made with the cyclotron for human welfare. (Wakatsuki, Y.)

  11. The Data Cyclotron query processing scheme

    NARCIS (Netherlands)

    Goncalves, R.; Kersten, M.

    2011-01-01

    A grand challenge of distributed query processing is to devise a self-organizing architecture which exploits all hardware resources optimally to manage the database hot set, minimize query response time, and maximize throughput without single point global coordination. The Data Cyclotron

  12. The Data Cyclotron query processing scheme.

    NARCIS (Netherlands)

    R.A. Goncalves (Romulo); M.L. Kersten (Martin)

    2011-01-01

    htmlabstractA grand challenge of distributed query processing is to devise a self-organizing architecture which exploits all hardware resources optimally to manage the database hot set, minimize query response time, and maximize throughput without single point global coordination. The Data Cyclotron

  13. Cyclotron-based neutron source for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

    2013-04-19

    Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

  14. <600> MeV synchro-cyclotron

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  15. Helical axial injection concept for cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical.

  16. Helical axial injection concept for cyclotrons

    International Nuclear Information System (INIS)

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical

  17. Automated cyclotron tuning using beam phase measurements

    International Nuclear Information System (INIS)

    Timmer, J.H.; Roecken, H.; Stephani, T.; Baumgarten, C.; Geisler, A.

    2006-01-01

    The ACCEL K250 superconducting cyclotron is specifically designed for the use in proton therapy systems. The compact medical 250 MeV proton accelerator fulfils all present and future beam requirements for fast scanning treatment systems and is delivered as a turn key system; no operator is routinely required. During operation of the cyclotron heat dissipation of the RF system induces a small drift in iron temperature. This temperature drift slightly detunes the magnetic field and small corrections must be made. A non-destructive beam phase detector has been developed to measure and quantify the effect of a magnetic field drift. Signal calculations were made and the design of the capacitive pickup probe was optimised to cover the desired beam current range. Measurements showed a very good agreement with the calculated signals and beam phase can be measured with currents down to 3 nA. The measured phase values are used as input for a feedback loop controlling the current in the superconducting coil. The magnetic field of the cyclotron is tuned automatically and online to maintain a fixed beam phase. Extraction efficiency is thereby optimised continuously and activation of the cyclotron is minimised. The energy and position stability of the extracted beam are well within specification

  18. A visual assistance environment for cyclotron operation

    International Nuclear Information System (INIS)

    Okamura, Tetsuya; Murakami, Tohru; Agematsu, Takashi; Okumura, Susumu; Arakawa, Kazuo.

    1993-01-01

    A computer-based operation system for a cyclotron which assists inexperienced operators has been developed. Cyclotron start-up operations require dozens of adjustable parameters to be finely tuned to maximize extracted beam current. The human interfaces of the system provide a visual environment designed to enhance beam parameter adjustments. First, the mental model of operators is analyzed. It is supposed to be composed of five partial mental models: beam behavior model, feasible setting regions model, parameter sensitivity model, parameter mutual relation model, and status map model. Next, based on these models, three visual interfaces are developed, i.e., (1) Beam trajectory is rapidly calculated and graphically displayed whenever the operators change the cyclotron parameters. (2) Feasible setting regions (FSR) of the parameters that satisfy the cyclotron's beam acceptance criteria are indicated. (3) Search traces, being a historical visual map of beam current values, are superimposed on the FSRs. Finally, to evaluate system effectiveness, the search time required to reach maximum beam current conditions was measured. In addition, system operability was evaluated using written questionnaires. Results of the experiment showed that the search time to reach specific beam conditions was reduced by approximately 65% using these interfaces. The written questionnaires survey showed the operators highly evaluate system operability. (author)

  19. Microwave power coupling with electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    600 W microwave power with an average electron density of ∼ 6 × 1011 cm. −3 ... the angular frequency of the cyclotron motion, e is the electron charge, m is the mass of .... is also suitable for ECR plasma-based applications like high-quality ...

  20. Development of HM12 cyclotron for PET

    International Nuclear Information System (INIS)

    Morita, Takuzo; Kawama, Tetsuo; Fujii, Kazuo

    2000-01-01

    In Japan, there are at present more than 30 PET (Positron Emission Tomography) facilities. The movements of medical insurance application to the PET diagnosis using [ 18 F] FDG (2-[ 18 F]-fluoro-2-deoxy-glucose) by the Ministry of Health and Welfare are being enhanced by PET related people. Therefore, more clinical centers using PET system are expected to be built in the near future. HM12 cyclotron was developed to meet such market demands for PET, and the prototype machine has been rent to Cyclotron Radio Isotope Center (CYRIC) of Tohoku University since Oct. 1998 for their use of clinical research with positron emitters like 11 C, 13 N, 15 O and 18 F. We got many technical data of HM12 Cyclotron on the clinical base. The data was enough to establish the reliability of HM12 system operation under the clinical condition. The first commercial product of HM12 Cyclotron was delivered to National Cancer Center in March 2000. The final performance test will be finished by the end of June 2000. (author)

  1. Electron cyclotron emission from thermal plasmas

    International Nuclear Information System (INIS)

    Fidone, I.; Granata, G.

    1978-02-01

    Electron cyclotron radiation from a warm inhomogeneous plasma is investigated. A direct calculation of the emissive power of a plasma slab is performed using Rytov's method and the result is compared with the solution of the transfer equation. It is found that, for arbitrary directions of emission, the two results differ, which reflects the fact that Kirchhoff's law is not generally obeyed

  2. Electron cyclotron heating and associated parallel cooling

    International Nuclear Information System (INIS)

    Rapozo, C. da C.; Assis, A.S. de; Busnardo Neto, J.

    1990-01-01

    It has been experimentally observed that during the electron-cyclotron heating the electron longitudinal temperature drops as the perpendicular temperature increases. The experiment was carried in a linear mirror machine with a low density (10 10 cm -3 ) weakly ionized (< 1.0 %) plasma. (Author)

  3. On Resonant Heating Below the Cyclotron Frequency

    International Nuclear Information System (INIS)

    Chen, Liu; Lin, Zhihong; White, R.

    2001-01-01

    Resonant heating of particles by an electrostatic wave propagating perpendicular to a confining uniform magnetic field is examined. It is shown that, with a sufficiently large wave amplitude, significant perpendicular stochastic heating can be obtained with wave frequency at a fraction of the cyclotron frequency

  4. Emergency situation in a medical cyclotron facility

    International Nuclear Information System (INIS)

    Kumar, Rajeev; Bhat, M.K.; Singh, D.K.; Pthania, B.S.; Pandit, A.G.; Jacob, M.J.

    2010-01-01

    Full text: Medical cyclotron is a particle accelerator used in producing short lived radioisotopes such as 18 F, 11 C, 15 O, 13 N, 18 F-2 gas etc. Positron Emission Tomography (PET) is a nuclear imaging modality that has rapidly gained favour. 18 F-FDG is the most widely used radiopharmaceutical with a half-life of 109.8 min. Having more than five years experience in this field we face lots of emergency conditions in the medical cyclotron facility. On the basis of harm we have divided in to three categories i.e. Harm of (a) working personnel, (b) Equipment and (c) environment. Radioactive gas leak and Target foil rupture is considered as the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. Recommendations have also been made to reduce personal exposure while handling the radioactive gas leak and target foil rupture conditions

  5. Electron-cyclotron-resonance ion sources (review)

    International Nuclear Information System (INIS)

    Golovanivskii, K.S.; Dougar-Jabon, V.D.

    1992-01-01

    The physical principles are described and a brief survey of the present state is given of ion sources based on electron-cyclotron heating of plasma in a mirror trap. The characteristics of ECR sources of positive and negative ions used chiefly in accelerator technology are presented. 20 refs., 10 figs., 3 tabs

  6. Currents driven by electron cyclotron waves

    International Nuclear Information System (INIS)

    Karney, C.F.F.; Fisch, N.J.

    1981-07-01

    Certain aspects of the generation of steady-state currents by electron cyclotron waves are explored. A numerical solution of the Fokker-Planck equation is used to verify the theory of Fisch and Boozer and to extend their results into the nonlinear regime. Relativistic effects on the current generated are discussed. Applications to steady-state tokamak reactors are considered

  7. 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.

  8. Cyclotron resonance cooling by strong laser field

    International Nuclear Information System (INIS)

    Tagcuhi, Toshihiro; Mima, Kunioka

    1995-01-01

    Reduction of energy spread of electron beam is very important to increase a total output radiation power in free electron lasers. Although several cooling systems of particle beams such as a stochastic cooling are successfully operated in the accelerator physics, these cooling mechanisms are very slow and they are only applicable to high energy charged particle beams of ring accelerators. We propose here a new concept of laser cooling system by means of cyclotron resonance. Electrons being in cyclotron motion under a strong magnetic field can resonate with circular polarized electromagnetic field, and the resonance take place selectively depending on the velocity of the electrons. If cyclotron frequency of electrons is equal to the frequency of the electromagnetic field, they absorb the electromagnetic field energy strongly, but the other electrons remain unchanged. The absorbed energy will be converted to transverse kinetic energy, and the energy will be dumped into the radiation energy through bremastrahlung. To build a cooling system, we must use two laser beams, where one of them is counter-propagating and the other is co-propagating with electron beam. When the frequency of the counter-propagating laser is tuned with the cyclotron frequency of fast electrons and the co-propagating laser is tuned with the cyclotron frequency of slow electrons, the energy of two groups will approach and the cooling will be achieved. We solve relativistic motions of electrons with relativistic radiation dumping force, and estimate the cooling rate of this mechanism. We will report optimum parameters for the electron beam cooling system for free electron lasers

  9. HEATING AND CURRENT DRIVE BY ELECTRON CYCLOTRON WAVES

    International Nuclear Information System (INIS)

    Prater, R.

    2003-01-01

    OAK-B135 The physics model of electron cyclotron heating (ECH) and current drive (ECCD) is becoming well validated through systematic comparisons of theory and experiment. This work has shown that ECH and ECCD can be highly localized and robustly controlled in toroidal plasma confinement systems, leading to applications including stabilization of magnetohydrodynamic (MHD) instabilities like neoclassical tearing modes, control and sustainment of desired profiles of current density and plasma pressure, and studies of localized transport in laboratory plasmas. The experimental work was supported by a broad base of theory based on first principles which is now well encapsulated in linear ray tracing codes describing wave propagation, absorption, and current drive and in fully relativistic quasilinear Fokker-Planck codes describing in detail the response of the electrons to the energy transferred from the wave. 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. 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. The agreement of theory and experiment, the wide range of established applications, and the technical advantages of ECH support the application of ECH in next-step tokamaks and stellarators

  10. Electron-cyclotron maser emission during solar and stellar flares

    International Nuclear Information System (INIS)

    Winglee, R.M.

    1985-01-01

    Radio bursts, with high brightness temperature 10 to the 10th power K and high degree of polarization, and the heating of the solar and stellar coronae during flares have been attributed to emission from the semirelativistic maser instability. In plasmas where the electron-plasma frequency, p, omega sub p, and the electron-cyclotron frequency, Omega sub e, are such that omega sup 2 sub p/Omega sup 2 sub e 1, x-mode growth dominates while z-mode growth dominates if omega sup 2 sub p/Omega sup 2 sub e is of order unity. The actual value of omega sup 2 sub p/Omega sup 2 sub e at which x-mode growth dominates is shown to be dependent on the plasma temperature with x-mode growth dominating at higher omega sub p/Omega sub e as the plasma temperature increases. Observations from a set of 20 impulsive flares indicate that the derived conditions for the dominance of x-mode growth are satisfied in about 75 percent of the flares

  11. Heating of Solar Wind Ions via Cyclotron Resonance

    Science.gov (United States)

    Navarro, R.; Moya, P. S.; Figueroa-Vinas, A.; Munoz, V.; Valdivia, J. A.

    2017-12-01

    Remote and in situ observations in the solar wind show that ion and electron velocity distributions persistently deviate from thermal equilibrium in the form of relative streaming between species components, temperature anisotropy, etc. These non-thermal features represent a source of free energy for the excitation of kinetic instabilities and fluctuations in the plasma. In this regard, it is believed that plasma particles can be heated, through a second order Fermi acceleration process, by multiple resonances with unstable counter-propagating field-aligned Ion-cyclotron waves. For multi-species plasmas, several collective wave modes participate in this process. In this work, we test this model by studying the percentage of ions that resonate with the waves modes described by the proper kinetic multi-species dispersion relation in a solar-wind-like plasma composed of electrons, protons, and alpha particles. Numerical results are compared with WIND spacecraft data to test its relevance for the existence of thresholds for the preferential perpendicular heating of He+2 ions as observed in the solar wind fast streams.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

    An expression for the linear electromagnetic ion cyclotron convective growth rate has been derived, considering multiple ions in the energetic anisotropic component of the plasma (which provides the free energy for the instability) as well as in the cold component of the plasma. This represents a modification of recent treatments investigating electromagnetic ion cyclotron growth rates which have considered only hydrogen ions in the energetic component. Four major effects on the growth and propagation characteristics result from inclusion of heavy ions in the energetic component. Some wave growth occurs at low frequencies below the corresponding marginally unstable wave mode for each heavy ion. Enhanced quasi-monochronomatic peaks in the convective growth rate appear just below the O + and He + gyrofrequency and can be quite pronounced for certain plasma conditions. Stop bands, decreased group velocity and other effects normally attributed to cold heavy ions can be produced or enhanced by heavy ions in the energetic plasma component. Partial or complete suppression of wave growth at frequencies above the marginally unstable wave mode for a particular energetic heavy ion can greatly alter the growth rates that would occur in the absence of this energetic heavy ion. The expression for the linear electromagnetic ion cyclotron convective growth rate along with appropriate plasma parameters was used to investigate the nature of linear wave growth in the plasmapause region. The frequencies of peaks in the convective growth rate given by this model compare favorably with wave measurements in this region. It is conceivable that through wave-particle interactions, electromagnetic ion cyclotron waves could supply the energy source for various plasmapause region phenomena such as the O + torus, the plasma cloak and stable auroral red arcs

  13. Directory of cyclotrons used for radionuclide production in Member States

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that {sup 15}O-oxygen PET studies in Japan, and {sup 18}F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies.

  14. Directory of cyclotrons used for radionuclide production in Member States

    International Nuclear Information System (INIS)

    1998-03-01

    The directory of cyclotrons used for radionuclide production is an update of the data base on cyclotrons that was compiled in 1983 by the International Atomic Energy Agency. The directory contains technical, utilization and administrative information supplied to the IAEA as of October 1997. The directory was prepared through information collected by questionnaires sent to institutions that either have a cyclotron, or that were identified to be in the process of installation of a cyclotron. The directory contains 206 entries for cyclotrons operating in 34 Member States. The largest concentration of cyclotrons for radionuclide production are located in the United States of America (66), Japan (33) and Germany (22). The largest number of cyclotrons for a single country is the United States of America. The expansion in number of cyclotrons during the last decade has been driven by the advent of advances in medical imaging instrumentation (PET, SPET and more recently 511 KeV emission tomography); introduction of user friendly compact medical cyclotrons from several companies that manufacture cyclotrons; and recent decisions that 15 O-oxygen PET studies in Japan, and 18 F-FDG PET studies in Germany are eligible for reimbursement by government or insurance companies

  15. Joint Instability and Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Darryl Blalock

    2015-01-01

    Full Text Available Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA. Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  16. Joint instability and osteoarthritis.

    Science.gov (United States)

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  17. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.

    Science.gov (United States)

    Nagornov, Konstantin O; Kozhinov, Anton N; Tsybin, Yury O

    2017-04-01

    The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ω c . In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ω c quantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω + ), whereas the ω c and the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω + quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ω c frequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω + frequencies can be reduced to negligible levels relative to peaks close to ω c frequencies. Due to reduced errors with which the ω c quantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω + frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.

  18. Radiation protection of cyclotron vault with maze in PET Cyclotron Center

    International Nuclear Information System (INIS)

    Fueloep, Marko

    2003-01-01

    The PET Cyclotron center (PCC) is a complex for production, research and application of positron radiopharmaceuticals for PET (Positron Emission Tomography), which was commissioned this year (2004) in Bratislava, Slovak Republic. Positron radionuclides are produced by 18/9 MeV proton/deuteron cyclotron CYCLONE 18/9. Radiation protection of personnel and inhabitants against ionizing radiation in the PCC is solved with regard to the ICRP recommendations and Slovak regulatory system, protection rules and criteria and optimization of radiation protection. In the article comparisons of calculated and measured neutron and gamma dose equivalent rates around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze are presented. Description of the CYCLONE 18/9 as a source of angular distribution of neutron energy spectra (production of 18 F was considered) was simulated by Monte Carlo code MCNPX. Code MCNP4B was used for shielding calculation of cyclotron vault with maze. Neutron energy spectra behind the shielding were measured by Bonner spectrometer. The values of neutron dose equivalent, which were calculated and measured around the CYCLONE 18/9 and at various points behind the shielding of cyclotron vault with maze, are within the range of factor 2. (authors)

  19. The Cyclotron Center of the Slovak Republic

    International Nuclear Information System (INIS)

    Podhorsky, D.; Ruzicka, J.; Macasek, F.; Makaiova, I.; Saro, S.; Kristiak, J.; Fulup, M.

    2001-01-01

    The Cyclotron Center of the Slovak Republic was established at the beginning of August 1999 - within the Slovak-Office of Standards, Metrology and Testing (SOSMT), in Bratislava, Slovak Republic. It will have two cyclotrons - a large heavy and light cyclotron DC-72, which will be constructed by the Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation, and a small commercial light ion cyclotron IBA 18/9. The heavy ion source of the electron resonance type (DECRS-2M) will be used for low and medium energy experiments in physics. The small electron accelerator is planned for different applications, including improving the properties of plastics, increasing the resistance of cables to fire and temperature, the sterilization of medical disposables in the CC SR. The main purpose of the Cyclotron Center of the Slovak Republic (CC SR) is to catch the present approach and trends in the area of improving of inhabitants life and health quality using the progressive technology, which is introduced by bringing into practice of the physical equipment - accelerators, producing beams of high energy particles. Experts of nuclear physics and of the related branches have no experimental basis in Slovakia, as after dissolution of the former the Czech and Slovak Federal Republic all bigger nuclear equipment were left in the Czech Republic. The Slovak Republic is one of the European countries where cancer and cardiovascular diseases have a rapidly increasing tendency (the rate of new oncological cases is approximately 20,000/year at the population of 5 million inhabitants) - early diagnostics of population is necessary to be updated urgently. The Slovak Republic use a great part of electricity (about 60 %) from its own nuclear power stations and thus it is in need of education of rising generations of experts from different nuclear fields. The Government of the Slovak republic on June 18, 1996 approved the strategic aim of building up the Cyclotron Laboratory at the

  20. Research and education by SF cyclotron facility

    International Nuclear Information System (INIS)

    1992-04-01

    This report represents the current activities in research and education using the cyclotron facility and related apparatus which are supported by Nuclear Physics Division and this is a continuation of INS-T-466 (1986, December). In this version an iron-free β-ray spectrometer and a cooler-synchrotron (TARN II) are briefly described also in the first chapter. The second chapter explains experimental programs performed in the last 5 years. The third chapter gives the number of publications on researches performed in 1975-1991, and also gives twelve topics obtained from the cyclotron and the β-ray spectrometer in recent 5 years. The last chapter provides the whole list of the works for Doctor and Master theses performed at the facility in the last 10 years. (J.P.N.)

  1. MMS Observations of Harmonic Electromagnetic Cyclotron Waves

    Science.gov (United States)

    Usanova, M.; Ahmadi, N.; Ergun, R.; Trattner, K. J.; Fuselier, S. A.; Torbert, R. B.; Mauk, B.; Le Contel, O.; Giles, B. L.; Russell, C. T.; Burch, J.; Strangeway, R. J.

    2017-12-01

    Harmonically related electromagnetic ion cyclotron waves with the fundamental frequency near the O+ cyclotron frequency were observed by the four MMS spacecraft on May 20, 2016. The wave activity was detected by the spacecraft on their inbound passage through the Earth's morning magnetosphere during generally quiet geomagnetic conditions but enhanced solar wind dynamic pressure. It was also associated with an enhancement of energetic H+ and O+ ions. The waves are seen in both magnetic and electric fields, formed by over ten higher order harmonics, most pronounced in the electric field. The wave activity lasted for about an hour with some wave packets giving rise to short-lived structures extending from Hz to kHz range. These observations are particularly interesting since they suggest cross-frequency coupling between the lower and higher frequency modes. Further work will focus on examining the nature and role of these waves in the energetic particle dynamics from a theoretical perspective.

  2. Neutron radiography with the cyclotron, 3

    International Nuclear Information System (INIS)

    Hiraoka, Eiichi; Fujishiro, Masatoshi; Tsujii, Yukio

    1985-01-01

    Neutron radiography is well recognized as a powerful tool in nondestructive testing, but not widely used yet owing to lack of high intense thermal neutron source convenient for practical use. A new neutron radiograph facility, utilizing a sub-compact cyclotron as neutron source and equipped with vertical and horizontal irradiation ports, is presented in this article. A series of experiment, prior to its construction, was conducted using beams of a variable energy cyclotron at Tohoku University to investigate the characteristics of thermal neutron obtained, from 9 Be (p, n) reaction and thermalized by elastic scattering process. This article describes a computer simulation of neutron moderator to analyze conditions getting maximal thermal neutron flux. Some of practical neutron radiograph examination of aero-space components and museum art objects of classic bronze mirror are also presented together with an attempt realizing real time imaging technique. (author)

  3. Research activities by INS cyclotron facility

    International Nuclear Information System (INIS)

    1992-06-01

    Research activities made by the cyclotron facility and the related apparatuses at Institute for Nuclear Study (INS), University of Tokyo, have been reviewed in terms of the associated scientific publications. This publication list, which is to be read as a continuation of INS-Rep.-608 (October, 1986), includes experimental works on low-energy nuclear physics, accelerator technology, instrumental developments, radiation physics and other applications in interdisciplinary fields. The publications are classified into the following four categories. (A) : Internal reports published in INS. (B) : Publications in international scientific journals on experimental research works done by the cyclotron facility and the related apparatuses at INS. Those made by outside users are also included. (C) : Publications in international scientific journals on experimental low-energy nuclear physics, which have been done by the staff of INS Nuclear Physics Division using facilities outside INS. (D) : Contributions to international conferences. (author)

  4. New design for a medical cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M

    1985-12-01

    The Oxford Instruments Group PLC, have designed a 30 MeV energy proton cyclotron incorporating a super-conducting magnet and a novel RF accelerating cavity. The energy range is suitable for the production of isotopes such as /sup 67/Ga, /sup 111/In, /sup 123/I and /sup 201/Tl, and the short lived isotopes of carbon, nitrogen, oxygen and fluorine for use in Positron Emmission Tomography (PET). A new magnet and RF cavity design permit a considerable power and weight reduction and a compact size (1.5m dia x 1.9m high), allowing the cyclotron to be transported to a shielded site as an assembly after factory testing. A method of beam extraction has been adopted which minimises activation of the accelerator components and so allows hands on maintenance to be carried out when required.

  5. Matching of ion sources to cyclotron inflectors

    International Nuclear Information System (INIS)

    Baartman, R.

    1988-06-01

    In general, cyclotron inflectors strongly couple the two transverse subspaces. This leads to a growth in emittance projections for a beam with no initial correlation between the two transverse subspaces. Only in the case of the Mueller (hyperboloid) inflector is there no emittance growth. We have made calculations using an optimization routine to match a given beam through the axial injection system. We find that in the limit where all the emittance is due to a beam's axial angular momentum (for example, from an ECR source), matching with no emittance growth is possible even in the case of mirror or spiral inflectors. Moreover, any one of the two transverse emittances circulating in the cyclotron can be made smaller than the source emittance while maintaining the sum of the emittances constant. This is achieved by rotating the matching quadrupoles with respect to the inflector and retuning

  6. Cyclotrons as Drivers for Precision Neutrino Measurements

    International Nuclear Information System (INIS)

    Alonso, J.; Barletta, W. A.; Winslow, L. A.; Shaevitz, M. H.; Spitz, J.; Conrad, J. M.; Toups, M.; Adelmann, A.

    2014-01-01

    As we enter the age of precision measurement in neutrino physics, improved flux sources are required. These must have a well defined flavor content with energies in ranges where backgrounds are low and cross-section knowledge is high. Very few sources of neutrinos can meet these requirements. However, pion/muon and isotope decay-at-rest sources qualify. The ideal drivers for decay-at-rest sources are cyclotron accelerators, which are compact and relatively inexpensive. This paper describes a scheme to produce decay-at-rest sources driven by such cyclotrons, developed within the DAEδALUS program. Examples of the value of the high precision beams for pursuing Beyond Standard Model interactions are reviewed. New results on a combined DAEδALUS—Hyper-K search for CP violation that achieve errors on the mixing matrix parameter of 4° to 12° are presented

  7. 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.

  8. Electron cyclotron emission from the PLT tokamak

    International Nuclear Information System (INIS)

    Hosea, J.; Arunasalam, V.; Cano, R.

    1977-07-01

    Experimental measurements of electron cyclotron emission from the PLT tokamak plasma reveal that black-body emission occurs at the fundamental frequency. Such emission, not possible by direct thermal excitation of electromagnetic waves, is herein attributed to thermal excitation of electrostatic (Bernstein) waves which then mode convert into electromagnetic waves. The local feature of the electrostatic wave generation permits spatially and time resolved measurements of electron temperature as for the second harmonic emission

  9. Use of maze in cyclotron hoppers

    International Nuclear Information System (INIS)

    Fernandes, Fernando A.; Alves, Juliano S.; Fochesatto, Cintia; Cerioli, Luciane; Borges, Joao Alfredo; Gonzalez, Delfin; Silva, Daniel C.

    2013-01-01

    Introduction: the increasing number of cyclotrons in Brazil due to constitutional amendment 49 /06 that enabled the production of radiopharmaceuticals with a short half - life by private companies. The radionuclides used for PET - CT require production centers near or within the diagnostic centers. In order to minimize maintenance and operating risks, gaining efficiency, our facility was the first in Brazil to use the access to a cyclotron bunker via maze, rather than armored door stopper type. Materials: the design calculations were based on the Monte Carlo method (MCNP5 - Monte Carlo N-Particletransportcode version 5). At the ends of the labyrinth are installed a door of polyethylene, for thermalization of neutrons, and other of wood for limiting access. Both legs of the maze have wall thickness of 100cm. In inspection Brazilian CNEN realize measures of dose rate for neutrons and gamma 9 points: 7 around the bunker, 1 over the bunker and 1 in the exhaust with the cyclotron operating with maximum load, double beam of 50uA for 2 hours. After commissioning were carried out around the bunker, the following measures: cumulative dose in three months with dosimeters for neutron rate dose with a gas proportional detector type filled with 3 He and polyethylene neutron moderator and dose rate with a Geiger - Mueller detector for gamma radiation. Readings with neutron detectors were classified as background radiation and dose rates were always below the limits established in standard EN 3.01, and the calculation of the predicted regardless of the intensity of irradiation inside the bunker. Conclusion: the use of labyrinths as a way to access the bunkers cyclotron has been shown to be effective as the radiation shielding and efficient by allowing quick and easy access, virtually eliminating the maintenance

  10. The superconducting separated orbit cyclotron TRITRON

    International Nuclear Information System (INIS)

    Trinks, U.

    1984-01-01

    At the Munich 13 MV-Tandem Laboratory the TRITRON is under development, which will be the prototype of a superconducting separated orbit cyclotron for acceleration of heavy ions with 0.04 or approx.20) of the revolution frequency. Thus the frequency range for acceleration of ions with different revolution frequency can be kept small (+-3%). The magnets as well as the cavities are contained in the same cavity. (orig.)

  11. DAISY - the Oslo Cyclotron data acquisition system

    International Nuclear Information System (INIS)

    Ramsoey, T.

    1991-08-01

    The new CACTUS multidetector system for the Oslo Cyclotron consists of 8 particle telescopes, 28 NAI detectors and 2 Ge detectors. Each detector gives rise to one energy parameter and one time parameter. Thus, a total of 80 parameters are present. The counting rate is 100 kByte/s for the highest beam intensities. A new data acquisition system, DAISY, satisfying these demands has been designed. The present report is intended as a complete technical manual for the new system. 24 refs

  12. Electron cyclotron resonance multiply charged ion sources

    International Nuclear Information System (INIS)

    Geller, R.

    1975-01-01

    Three ion sources, that deliver multiply charged ion beams are described. All of them are E.C.R. ion sources and are characterized by the fact that the electrons are emitted by the plasma itself and are accelerated to the adequate energy through electron cyclotron resonance (E.C.R.). They can work without interruption during several months in a quasi-continuous regime. (Duty cycle: [fr

  13. Cyclotron heating rate in a parabolic mirror

    International Nuclear Information System (INIS)

    Smith, P.K.

    1984-01-01

    Cyclotron resonance heating rates are found for a parabolic magnetic mirror. The equation of motion for perpendicular velocity is solved, including the radial magnetic field terms neglected in earlier papers. The expression for heating rate involves an infinite series of Anger's and Weber's functions, compared with a single term of the unrevised expression. The new results show an increase of heating rate compared with previous results. A simple expression is given for the ratio of the heating rates. (author)

  14. First experimental observation of cyclotron superradiance

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, N S; Zotova, I V; Sergeev, A S; Konoplev, I V [Russian Academy of Sciences, Nizhny Novgorod (Russian Federation). Inst. of Applied Physics; Shpak, V G; Yalandin, M I; Shunajlov, C A; Ulmaskulov, M P [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Electrophysics

    1997-12-31

    The first experimental observation of cyclotron superradiance from subnanosecond high-current electron bunches moving through waveguide systems is reported. Ultrashort microwave K{sub {alpha}} band pulses with a power of 200 kW and duration less than 0.5 ns were observed in the regime of group synchronism when the electron bunch drift velocity coincided with the group velocity of the electromagnetic waves. (author). 2 figs., 13 refs.

  15. Electron cyclotron emission measurement in Tore Supra

    International Nuclear Information System (INIS)

    Javon, C.

    1991-06-01

    Electron cyclotron radiation from Tore-Supra is measured with Michelson and Fabry-Perot interferometers. Calibration methods, essential for this diagnostic, are developed allowing the determination of electron temperature in the plasma. In particular the feasibility of Fabry-Perot interferometer calibration by an original method is demonstrated. A simulation code is developed for modelling non-thermal electron population in these discharges using measurements in non-inductive current generation regime [fr

  16. Modular beam diagnostics instrument design for Cyclotrons

    International Nuclear Information System (INIS)

    Chaddha, N.; Bhole, R.B.; Sahoo, S.; Nandy, P.P.; Pal, S.

    2012-01-01

    The Cyclotrons at VECC, Kolkata i.e. Room Temperature Cyclotron (RTC) and Superconducting Cyclotron (SCC) comprise of internal and external Beam Diagnostic systems. These systems provide the beam developer with position, intensity, beam profile, a visual impression of the size and shape of ion beam, and operational control over diagnostic components like 3-finger probe, Beam Viewer probe, Deflector probe, Faraday cup, X-Y slit, Beam viewer etc. Automation of these components was initially done using customised modules for individual sub-system. An expansion of this facility and various levels of complexity demand modular design to cater easy modification and upgradation. The overall requirements are analysed and modular cards are developed based on basic functionalities like valve operation, probe/slit/viewer control, position read-out, Interlock, aperture control of beam line and communication. A 32-bit Advanced RISC Machine (ARM) based card with embedded EPICS is chosen as the master controller and FPGA/microcontroller is used for functional modules. The paper gives a comprehensive description of all modules and their integration with the control system. (author)

  17. Ion Cyclotron Heating on Proto-MPEX

    Science.gov (United States)

    Goulding, R. H.; Caughman, J. B. O.; Rapp, J.; Biewer, T. M.; Campbell, I. H.; Caneses, J. F.; Kafle, N.; Ray, H. B.; Showers, M. A.; Piotrowicz, P. A.

    2016-10-01

    Ion cyclotron heating will be used on Proto-MPEX (Prototype Material Plasma Exposure eXperiment) to increase heat flux to the target, to produce varying ion energies without substrate biasing, and to vary the extent of the magnetic pre-sheath for the case of a tilted target. A 25 cm long, 9 cm diameter dual half-turn helical ion cyclotron antenna has been installed in the device located at the magnetic field maximum. It couples power to ions via single pass damping of the slow wave at the fundamental resonance, and operates with ω 0.8ωci at the antenna location. It is designed to operate at power levels up to 30 kW, with a later 200 kW upgrade planned. Near term experiments include measuring RF loading at low power as a function of frequency and antenna gap. The plasma is generated by a helicon plasma source that has achieved ne > 5 ×1019m-3 operating with deuterium, as measured downstream from the ion cyclotron antenna location. Measurements will be compared with 1-D and 2-D models of RF coupling. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  18. Nonlinear cyclotron absorption and stimulated scattering

    International Nuclear Information System (INIS)

    Chung, T.H.

    1986-01-01

    In electron cyclotron resonance heating (ECRH), wave sources heating a plasma linearly with respect to intensity; but as the intensity of ECRH gets larger, there might appear nonlinear effects that would result in cutoff of net absorption. This thesis uses quantum mechanical theory to derive a threshold microwave intensity for nonlinear absorption. The quantum mechanical theory estimates that the threshold microwave intensity for nonlinear absorption is about 10 5 watts/cm 2 for a microwave heating experiment (T/sub e/ = 100 ev, λ = 3,783 cm, B = 2.5 kG). This value seems large considering the present power capabilities of microwave sources (10 2 ∼ 10 3 watts/cm 2 ), but for a low temperature plasma, this threshold will go down. There is another nonlinear phenomenon called stimulated cyclotron scattering that enhances photon scattering by electrons gyrating in a magnetic field. This is expected to prevent incoming photons from arriving at the central region of the fusion plasma, where absorption mainly takes place. Theory based on a photon transport model predicts that the threshold intensity for the stimulated cyclotron scattering is about 10 4 watts/cm 2 for the plasma parameters mentioned above. This value seems large also, but a longer wavelength of microwaves and a larger magnitude magnetic field, which will be the case in reactor type facilities, will lower the threshold intensity to levels comparable with the currently developed microwave sources

  19. Transparency of Magnetized Plasma at Cyclotron Frequency

    International Nuclear Information System (INIS)

    G. Shvets; J.S. Wurtele

    2002-03-01

    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

  20. Improving cancer treatment with cyclotron produced radionuclides

    International Nuclear Information System (INIS)

    Larson, S.M.; Finn, R.D.

    1992-01-01

    Our goal is to improve the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The grant includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. The radiochemistry group seeks to develop innovative cyclotron targetry, radiopharmaceuticals, and radiolabeled antibodies, which are then used to assess important unanswered questions in tumor pharmacology and immunology. Examples include selected positron emitting radionuclides, such as Iodine-124, and Ga-66; I-124, I-123, I-131 labeled iododeoxyuridine, C-11 colchicine, and antimetabolites, like C-11 methotrexate; and radiolabeled antibodies, 3F8, M195, A33, and MRK16 for application in the pharmacology and immunology projects. The pharmacology program studies tumor resistance to chemotherapy, particularly the phenomenon of multidrug resistance and the relationship between tumor uptake and retention and the tumor response for anti-metabolite drugs. The immunology program studies the physiology of antibody localization at the tissue level as the basis for novel approaches to improving tumor localization such as through the use of an artificial lymphatic system which mechanically reduces intratumoral pressures in tumors in vivo. Quantitative imaging approaches based on PET and SPECT in radioimmunotherapy are studied to give greater insight into the physiology of tumor localization and dosimetry

  1. Operation of a quasioptical electron cyclotron maser

    International Nuclear Information System (INIS)

    Morse, E.C.; Pyle, R.V.

    1984-12-01

    The electron cyclotron maser or gyrotron concept has been developed to produce sources producing 200 kW at 28 GHz continuously, and higher power outputs and frequencies in pulsed mode. These sources have been useful in electron cyclotron resonance heating (ECRH) in magnetically confined fusion devices. However, higher frequencies and higher power levels will be required in reactor-grade fusion plasmas, with likely requirements of 1.0 MW or more per source at 140 GHz. Conventional gyrotrons follow a trend of decreasing power for increasing frequency. In order to circumvent this problem, the quasioptical electron cyclotron maser was proposed. In this device, the closed resonator of the conventional gyrotron is replaced with an open, Fabry-Perot type resonator. The cavity modes are then the TEM-type modes of an optical laser. The advantage of this configuration is that the cavity size is not a function of frequency, since the length can be any half-integer number of wavelengths. Furthermore, the beam traverses across the cavity transverse to the direction of radiation output, and thus the rf window design is less complicated than in conventional tubes. The rf output, if obtained by diffraction coupling around one of the mirrors, could be in a TEM mode, which would allow for quasioptical transmission of the microwaves into the plasma in fusion devices. 4 references, 1 figure

  2. TFTR vertically viewing electron cyclotron emission diagnostic

    International Nuclear Information System (INIS)

    Taylor, G.

    1990-01-01

    The Tokamak Fusion Test Reactor (TFTR) Michelson interferometer has a spectral coverage of 75--540 GHz, allowing measurement of the first four electron cyclotron harmonics. Until recently the instrument has been configured to view the TFTR plasma on the horizontal midplane, primarily in order to measure the electron temperature profile. Electron cyclotron emission (ECE) extraordinary mode spectra from TFTR Supershot plasmas exhibit a pronounced, spectrally narrow feature below the second harmonic. A similar feature is seen with the ECE radiometer diagnostic below the electron cyclotron fundamental frequency in the ordinary mode. Analysis of the ECE spectra indicates the possibility of a non-Maxwellian 40--80 keV tail on the electron distribution in or near the core. During 1990 three vertical views with silicon carbide viewing targets will be installed to provide a direct measurement of the electron energy distribution at major radii of 2.54, 2.78, and 3.09 m with an energy resolution of approximately 20% at 100 keV. To provide the maximum flexibility, the optical components for the vertical views will be remotely controlled to allow the Michelson interferometer to be reconfigured to either the midplane horizontal view or one of the three vertical views between plasma shots

  3. Nonlinear excitation of electron cyclotron waves by a monochromatic strong microwave: computer simulation analysis of the MINIX results

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, H.; Kimura, T.

    1986-01-01

    Triggered by the experimental results of the MINIX, a computer simulation study was initiated on the nonlinear excitation of electrostatic electron cyclotron waves by a monochromatic electromagnetic wave such as the transmitted microwave in the MINIX. The model used assumes that both of the excited waves and exciting (pumping) electromagnetic wave as well as the idler electromagnetic wave propagate in the direction perpendicular to the external magnetic field. The simulation code used for this study was the one-and-two-half dimensional electromagnetic particle code named KEMPO. The simulation result shows the high power electromagnetic wave produces both the backscattered electromagnetic wave and electrostatic electron cyclotron waves as a result of nonlinear parametric instability. Detailed nonlinear microphysics related to the wave excitation is discussed in terms of the nonlinear wave-wave couplings and associated ponderomotive force produced by the high power electromagnetic waves. 2 references, 4 figures.

  4. Nonlinear excitation of electron cyclotron waves by a monochromatic strong microwave: computer simulation analysis of the MINIX results

    International Nuclear Information System (INIS)

    Matsumoto, H.; Kimura, T.

    1986-01-01

    Triggered by the experimental results of the MINIX, a computer simulation study was initiated on the nonlinear excitation of electrostatic electron cyclotron waves by a monochromatic electromagnetic wave such as the transmitted microwave in the MINIX. The model used assumes that both of the excited waves and exciting (pumping) electromagnetic wave as well as the idler electromagnetic wave propagate in the direction perpendicular to the external magnetic field. The simulation code used for this study was the one-and-two-half dimensional electromagnetic particle code named KEMPO. The simulation result shows the high power electromagnetic wave produces both the backscattered electromagnetic wave and electrostatic electron cyclotron waves as a result of nonlinear parametric instability. Detailed nonlinear microphysics related to the wave excitation is discussed in terms of the nonlinear wave-wave couplings and associated ponderomotive force produced by the high power electromagnetic waves. 2 references, 4 figures

  5. Diagnostic system for the nuclear medicine with baby cyclotron

    International Nuclear Information System (INIS)

    Kashihara, Masao; Wakasa, Shyuichiro

    1982-01-01

    The system of cyclotron nuclear medicine consists of ''RI-production by using the cyclotron'', ''production of radio-pharmaceuticals labeled with RI'', ''positron tomography''. On the other hand, Ultra compact cyclotron (Baby cyclotron) itself, RI production technique and positron tomography have been rapidly developed and advanced. We think that these three functions must be balance in the development in order to spread this system into the routine work in the hospital. However, since the technology of the synthesis for the labeled compounds is not so developed so far, more advance can be strongly expected. In this report, construction of the cyclotron nuclear medicine, utility for the practical use of RI produced by using the cyclotron, technique of RI production, and the studies on automated and efficient productions of radio-pharmaceuticals labeled with short-lived positron emitters for medical diagnostic use are described. (author)

  6. arXiv Cyclotrons: Magnetic Design and Beam Dynamics

    CERN Document Server

    Zaremba, Simon

    Classical, isochronous, and synchro-cyclotrons are introduced. Transverse and longitudinal beam dynamics in these accelerators are covered. The problem of vertical focusing and iscochronism in compact isochronous cyclotrons is treated in some detail. Different methods for isochronization of the cyclotron magnetic field are discussed. The limits of the classical cyclotron are explained. Typical features of the synchro-cyclotron, such as the beam capture problem, stable phase motion, and the extraction problem are discussed. The main design goals for beam injection are explained and special problems related to a central region with an internal ion source are considered. The principle of a Penning ion gauge source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different methods of (axial) injection are briefly outlined. Different solutions for beam extraction are described. These include the internal target, extracti...

  7. Hydrodynamic instabilities in inertial fusion

    International Nuclear Information System (INIS)

    Hoffman, N.M.

    1994-01-01

    This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability

  8. Calculation of proton beam initial orbit at cyclotron central region

    International Nuclear Information System (INIS)

    Pramudita Anggraita

    2012-01-01

    A calculation of proton beam initial orbits at cyclotron central region was carried out using Scilab 5.2.0. The calculation was done in 2 dimensions in a homogeneous magnetic field of 1.66 tesla at frequency of fourth harmonics. The positions of ion source, dees, and dummy dees follow those of GE Minitrace cyclotron, peak dee voltage 30 kV. The calculation yields result comparable to those simulated at KIRAMS-13 cyclotron. (author)

  9. Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 1

    International Nuclear Information System (INIS)

    1993-03-01

    The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

  10. Proceedings of eighth joint workshop on electron cyclotron emission and electron cyclotron resonance heating. Vol. 2

    International Nuclear Information System (INIS)

    1993-03-01

    The theory of electron cyclotron resonance phenomena is highly developed. The main theoretical tools are well established, generally accepted and able to give a satisfactory description of the main results obtained in electron cyclotron emission, absorption and current drive experiments. In this workshop some advanced theoretical and numerical tools have been presented (e.g., 3-D Fokker-Planck codes, treatment of the r.f. beam as a whole, description of non-linear and finite-beam effects) together with the proposal for new scenarios for ECE and ECA measurements (e.g., for diagnosing suprathermal populations and their radial transport). (orig.)

  11. Genomic instability following irradiation

    International Nuclear Information System (INIS)

    Hacker-Klom, U.B.; Goehde, W.

    2001-01-01

    Ionising irradiation may induce genomic instability. The broad spectrum of stress reactions in eukaryontic cells to irradiation complicates the discovery of cellular targets and pathways inducing genomic instability. Irradiation may initiate genomic instability by deletion of genes controlling stability, by induction of genes stimulating instability and/or by activating endogeneous cellular viruses. Alternatively or additionally it is discussed that the initiation of genomic instability may be a consequence of radiation or other agents independently of DNA damage implying non nuclear targets, e.g. signal cascades. As a further mechanism possibly involved our own results may suggest radiation-induced changes in chromatin structure. Once initiated the process of genomic instability probably is perpetuated by endogeneous processes necessary for proliferation. Genomic instability may be a cause or a consequence of the neoplastic phenotype. As a conclusion from the data available up to now a new interpretation of low level radiation effects for radiation protection and in radiotherapy appears useful. The detection of the molecular mechanisms of genomic instability will be important in this context and may contribute to a better understanding of phenomenons occurring at low doses <10 cSv which are not well understood up to now. (orig.)

  12. Cyclotron will not survive yet this year without state support

    International Nuclear Information System (INIS)

    Marcan, P.

    2005-01-01

    In this paper the project of the Cyclotron Center of the Slovak republic is described. On the basis of this project the state joint-stock company Biont was constituted. Small cyclotron is in operation; big cyclotron is in process of manufacture and it will be put in operation in 2007. Small cyclotron will be used for production of radiopharmaceuticals. Positron emission tomograph (PET) in Oncological Institute of St. Elizabeth (in Bratislava) and gamma camera in Central Military Hospital (in Ruzomberok) are constituents of the Biont. The PET will be also in Biont. The hadron therapy of ophthalmic tumors is planned. Financial plans of the Biont up to 2009 are presented

  13. The problems of high efficient extraction from the isochronous cyclotron

    International Nuclear Information System (INIS)

    Schwabe, J.

    1994-06-01

    The problem of high efficient extraction (η ≥ 50%) from isochronous cyclotrons (with the exception of the stripping method) is not completely solved up to this day. This problem is specifically important, because these cyclotrons are being also applied in the production of medical radioisotopes, labeled pharmaceuticals as well as in neutron therapy (oncology), machine industry, agriculture (plant mutagenesis), etc. The aim of the proposed topic is to solve this problem on the AIC-144 isochronous cyclotron in the INP (Institute of Nuclear Physics). Lately, a beam of 20 MeV deuterons with an efficiency of ca. 15% was extracted from this cyclotron. (author). 25 refs, 14 figs

  14. Cyclotron based nuclear science. Progress report, April 1, 1985-March 31, 1986

    International Nuclear Information System (INIS)

    Youngblood, D.H.

    1986-08-01

    Progress report for cyclotron based nuclear science cyclotron facility are summarized. Research is described under the headings heavy ion reactions, nuclear theory, atomic studies and activation analysis, superconducting cyclotron and instrumentation. Publications are listed

  15. Fire Hose Instability in the Multiple Magnetic Reconnection

    Science.gov (United States)

    Alexandrova, A.; Retino, A.; Divin, A. V.; Le Contel, O.; Matteini, L.; Breuillard, H.; Deca, J.; Catapano, F.; Cozzani, G.; Nakamura, R.; Panov, E. V.; Voros, Z.

    2017-12-01

    We present observations of multiple reconnection in the Earth's magnetotail. In particular, we observe an ion temperature anisotropy characterized by large temperature along the magnetic field, between the two active X-lines. The anisotropy is associated with right-hand polarized waves at frequencies lower than the ion cyclotron frequency and propagating obliquely to the background magnetic field. We show that the observed anisotropy and the wave properties are consistent with linear kinetic theory of fire hose instability. The observations are in agreement with the particle-in-cell simulations of multiple reconnection. The results suggest that the fire hose instability can develop during multiple reconnection as a consequence of the ion parallel anisotropy that is produced by counter-streaming ions trapped between the X-lines.

  16. Relationship Between the Parameters of the Linear and Nonlinear Wave Generation Stages in a Magnetospheric Cyclotron Maser in the Backward-Wave Oscillator Regime

    Science.gov (United States)

    Demekhov, A. G.

    2017-03-01

    By using numerical simulations we generalize certain relationships between the parameters of quasimonochromatic whistler-mode waves generated at the linear and nonlinear stages of the cyclotron instability in the backward-wave oscillator regime. One of these relationships is between the wave amplitude at the nonlinear stage and the linear growth rate of the cyclotron instability. It was obtained analytically by V.Yu.Trakhtengerts (1984) for a uniform medium under the assumption of constant frequency and amplitude of the generated wave. We show that a similar relationship also holds for the signals generated in a nonuniform magnetic field and having a discrete structure in the form of short wave packets (elements) with fast frequency drift inside each element. We also generalize the formula for the linear growth rate of absolute cyclotron instability in a nonuniform medium and analyze the relationship between the frequency drift rate in the discrete elements and the wave amplitude. These relationships are important for analyzing the links between the parameters of chorus emissions in the Earth's and planetary magnetospheres and the characteristics of the energetic charged particles generating these signals.

  17. 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

  18. Auroral ion beams and ion acoustic wave generation by fan instability

    Energy Technology Data Exchange (ETDEWEB)

    Vaivads, A

    1996-04-01

    Satellite observations indicate that efficient energy transport among various plasma particles and between plasma waves and plasma particles is taking place in auroral ion beam regions. These observations show that two characteristic wave types are associated with the auroral ion beam regions: electrostatic hydrogen cyclotron waves with frequencies above hydrogen gyrofrequency, and low frequency waves with frequencies below hydrogen gyrofrequency. We speculate that the low frequency waves can be ion acoustic waves generated through the fan instability. The presence of a cold background ion component is necessary for the onset of this instability. A cold ion component has been directly observed and has been indirectly suggested from observations of solitary wave structures. The wave-particle interaction during the development of the fan instability results in an efficient ion beam heating in the direction perpendicular to the ambient magnetic field. The fan instability development and the ion beam heating is demonstrated in a numerical particle simulation. 23 refs, 16 figs.

  19. Excitation of Ion Cyclotron Waves by Ion and Electron Beams in Compensated-current System

    Science.gov (United States)

    Xiang, L.; Wu, D. J.; Chen, L.

    2018-04-01

    Ion cyclotron waves (ICWs) can play important roles in the energization of plasma particles. Charged particle beams are ubiquitous in space, and astrophysical plasmas and can effectively lead to the generation of ICWs. Based on linear kinetic theory, we consider the excitation of ICWs by ion and electron beams in a compensated-current system. We also investigate the competition between reactive and kinetic instabilities. The results show that ion and electron beams both are capable of generating ICWs. For ICWs driven by ion beams, there is a critical beam velocity, v bi c , and critical wavenumber, k z c , for a fixed beam density; the reactive instability dominates the growth of ICWs when the ion-beam velocity {v}{bi}> {v}{bi}c and the wavenumber {k}zz≃ 2{k}zc/3 for a given {v}{bi}> {v}{bi}c. For the slow ion beams with {v}{bi}< {v}{bi}c, the kinetic instability can provide important growth rates of ICWs. On the other hand, ICWs driven by electron beams are excited only by the reactive instability, but require a critical velocity, {v}{be}c\\gg {v}{{A}} (the Alfvén velocity). In addition, the comparison between the approximate analytical results based on the kinetic theory and the exact numerical calculation based on the fluid model demonstrates that the reactive instabilities can well agree quantitatively with the numerical results by the fluid model. Finally, some possible applications of the present results to ICWs observed in the solar wind are briefly discussed.

  20. Tearing instabilities in turbulence

    International Nuclear Information System (INIS)

    Ishizawa, A.; Nakajima, N.

    2009-01-01

    Full text: Effects of micro-turbulence on tearing instabilities are investigated by numerically solving a reduced set of two-fluid equations. Micro-turbulence excites both large-scale and small-scale Fourier modes through energy transfer due to nonlinear mode coupling. The energy transfer to large scale mode does not directly excite tearing instability but it gives an initiation of tearing instability. When tearing instability starts to grow, the excited small scale mode plays an important role. The mixing of magnetic flux by micro-turbulence is the dominant factor of non-ideal MHD effect at the resonant surface and it gives rise to magnetic reconnection which causes tearing instability. Tearing instabilities were investigated against static equilibrium or flowing equilibrium so far. On the other hand, the recent progress of computer power allows us to investigate interactions between turbulence and coherent modes such as tearing instabilities in magnetically confined plasmas by means of direct numerical simulations. In order to investigate effects of turbulence on tearing instabilities we consider a situation that tearing mode is destabilized in a quasi-equilibrium including micro-turbulence. We choose an initial equilibrium that is unstable against kinetic ballooning modes and tearing instabilities. Tearing instabilities are current driven modes and thus they are unstable for large scale Fourier modes. On the other hand kinetic ballooning modes are unstable for poloidal Fourier modes that are characterized by ion Larmor radius. The energy of kinetic ballooning modes spreads over wave number space through nonlinear Fourier mode coupling. We present that micro-turbulence affects tearing instabilities in two different ways by three-dimensional numerical simulation of a reduced set of two-fluid equations. One is caused by energy transfer to large scale modes, the other is caused by energy transfer to small scale modes. The former is the excitation of initial

  1. Method of enhancing cyclotron beam intensity

    Science.gov (United States)

    Hudson, Ed D.; Mallory, Merrit L.

    1977-01-01

    When an easily ionized support gas such as xenon is added to the cold cathode in sources of the Oak Ridge Isochronous Cyclotron, large beam enhancements are produced. For example, .sup.20 Ne.sup.7+ is increased from 0.05 enA to 27 enA, and .sup.16 O.sup.5+ intensities in excess of 35 e.mu.A have been extracted for periods up to 30 minutes. Approximately 0.15 cc/min of the easily ionized support gas is supplied to the ion source through a separate gas feed line and the primary gas flow is reduced by about 30%.

  2. New compact cyclotron design for SPIRAL

    International Nuclear Information System (INIS)

    Duval, M.; Bourgarel, M.P.; Ripouteau, F.

    1995-01-01

    The SPIRAL project whose purpose is the production and the acceleration of radioactive nuclei is under realization at GANIL. The new facility uses a cyclotron as post accelerator taking place behind the present machine. The magnet structure is made of 4 independent return yokes and a common circular pole piece (3.5 m in diameter) with 4 sectors. The average induction needed is 1.56 Tesla with hill and valley gaps of respectively 0.12 and 0.3 m. The required field patterns are adjusted by means of circular trim coils located between the sectors and the pole piece. (author)

  3. Isotope separation by ionic cyclotron resonance

    International Nuclear Information System (INIS)

    Compant La Fontaine, A.; Gil, C.; Louvet, P.

    1986-10-01

    The principle of the process of isotopic separation by ionic cyclotron resonance is explained succinctly. The theoretical calculation of the isotopic effect is given as functions of the electric and magnetic fields in the frame of single particle approximation and of plasma collective theory. Then, the main parts of the demonstration device which is in operation at the CEA, are described here: the supraconducting magnetic field, the used diagnostics, the principle of the source and the collecting apparatus. Some experimental results are given for chromium. The application of the process to ponderal separation of metal isotopes, as chromium, nickel and molybdenum is discussed in view of production of medical, structural and irradiation isotopes

  4. Diffusion induced by cyclotron resonance heating

    International Nuclear Information System (INIS)

    Riyopoulos, S.; Tajima, T.; Hatori, T.; Pfirsch, D.

    1985-09-01

    The wave induced particle transport during the ion cyclotron resonance heating is studied in collisionless toroidal plasmas. It is shown that the previously neglected non-conservation of the toroidal angular momentum IP/sub phi/ caused by the toroidal wave component E/sub phi/ is necessary to allow particle diffusion and yields the leading diffusive contribution. While the induced ion transport for the rf power in contemporary experiments is of the order of the neoclassical value, that of fast alpha particles is quite large if resonance is present

  5. Cyclotron resonance in a cathode ray tube

    International Nuclear Information System (INIS)

    Gherbanovschi, N.; Tanasa, M.; Stoican, O.

    2002-01-01

    Absorption of the RF energy by the electron beam in a cathode ray tube due to the cyclotron resonance is described. The cathode ray tube is placed within a Helmholtz coils system supplied by a sawtooth current generator. In order to generate RF field and to detect RF absorption a gate dip-meter equipped with a FET transistor is used. The bias voltage variations of the FET transistors as a function of the magnetic field are recorded. The operating point of the cathode ray tube has been chosen so that the relaxation oscillations of the detection system can be observed. (authors)

  6. Properties of the TRIUMF cyclotron beam

    International Nuclear Information System (INIS)

    Craddock, M.K.; Blackmore, E.W.; Dutto, G.; Kost, C.J.; Mackenzie, G.H.; Richardson, J.R.; Root, L.W.; Schmor, P.

    1975-08-01

    Eight percent of the 300 keV d.c. beam from the ion source can be transmitted to 500 MeV in the TRIUMF cyclotron, without using the buncher. The beam losses are entirely accounted for; there are no significant losses due to orbit dynamic problems during 1500 turns of acceleration. The phase history is in good agreement with predictions based on the magnetic field survey. The effect of the harmonic coils and injection parameters on beam quality has been investigated. (author)

  7. High efficiency cyclotron trap assisted positron moderator

    OpenAIRE

    Gerchow, L.; Cooke, D. A.; Braccini, S.; Döbeli, M.; Kirch, K.; Köster, U.; Müller, A.; Van Der Meulen, N. P.; Vermeulen, C.; Rubbia, A.; Crivelli, P.

    2017-01-01

    We report the realisation of a cyclotron trap assisted positron tungsten moderator for the conversion of positrons with a broad keV- few MeV energy spectrum to a mono-energetic eV beam with an efficiency of 1.8(2)% defined as the ratio of the slow positrons divided by the $\\beta^+$ activity of the radioactive source. This is an improvement of almost two orders of magnitude compared to the state of the art of tungsten moderators. The simulation validated with this measurement suggests that usi...

  8. Axial injection in Orsay superconducting cyclotron

    International Nuclear Information System (INIS)

    Depauw, J.; Kugler, M.F.; Legoff, A.; Potier, J.C.; Richomme, A.; Skowron, R.; Mandrillon, P.; Schapira, J.P.

    1983-01-01

    The compact superconducting cyclotron currently planned at IPN at Orsay is designed for light ion acceleration together with heavy ion acceleration. From the beginning, for this reason, a central geometry able to receive an inflector (to 90deg C) allowing the axial injection of low energy ion beams given by an outer source. The present study is aimed at showing the technical feasibility of theoretical results obtained on axial injection. First experimental study has been made of spatial repartition in three dimensions of electric potential developed by a central geometry of 3 electrodes. Then, the electric study of an electrostatic mirror has been made [fr

  9. Modeling Whistler Wave Generation Regimes In Magnetospheric Cyclotron Maser

    Science.gov (United States)

    Pasmanik, D. L.; Demekhov, A. G.; Trakhtengerts, V. Y.; Parrot, M.

    Numerical analysis of the model for cyclotron instability development in the Earth magnetosphere is made.This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. Two different mechanisms of energetic electron loss from the interaction region are discussed. The first one is precipitation of energetic particles via the loss cone. The other mechanism is drift of particles away from the interaction region across the mag- netic field line. In the case of interaction in plasmasphere or rather large areas of cold plasma density enhancement the loss cone precipitation are dominant. For interaction in a subauroral duct losses due to drift are most effective. A parametric study of the model for both mechanisms of particle losses is made. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch-angle distributions and elec- tron density. We show that in addition to the well-known stationary generation and periodic regime with successive spikes of similar shape, more complex forms of wave spectrum exist. In particular, we found a periodic regime, in which a single period in- cludes two separate spikes with different spectral shapes. In another regime, periodic generation of spikes at higher frequencies together with quasi-stationary generation at lower frequencies occurs. Quasi-periodic regime with spike overlapping, i.e. when generation of a new spike begins before the previous one is over is also found. Results obtained are compared with experimental data on quasi-periodic regimes of whistler wave generation.

  10. Modeling whistler wave generation regimes in magnetospheric cyclotron maser

    Directory of Open Access Journals (Sweden)

    D. L. Pasmanik

    2004-11-01

    Full Text Available Numerical analysis of the model for cyclotron instability in the Earth's magnetosphere is performed. This model, based on the self-consistent set of equations of quasi-linear plasma theory, describes different regimes of wave generation and related energetic particle precipitation. As the source of free energy the injection of energetic electrons with transverse anisotropic distribution function to the interaction region is considered. A parametric study of the model is performed. The main attention is paid to the analysis of generation regimes for different characteristics of energetic electron source, such as the shape of pitch angle distributions and its intensity. Two mechanisms of removal of energetic electrons from a generation region are considered, one is due to the particle precipitation through the loss cone and another one is related to the magnetic drift of energetic particles.

    It was confirmed that two main regimes occur in this system in the presence of a constant particle source, in the case of precipitation losses. At small source intensity relaxation oscillations were found, whose parameters are in good agreement with simplified analytical theory developed earlier. At a larger source intensity, transition to a periodic generation occurs. In the case of drift losses the regime of self-sustained periodic generation regime is realized for source intensity higher than some threshold. The dependencies of repetition period and dynamic spectrum shape on the source parameters were studied in detail. In addition to simple periodic regimes, those with more complex spectral forms were found. In particular, alteration of spikes with different spectral shape can take place. It was also shown that quasi-stationary generation at the low-frequency band can coexist with periodic modulation at higher frequencies.

    On the basis of the results obtained, the model for explanation of

  11. Ponderomotive force effects on temperature-gradient-driven instabilities

    International Nuclear Information System (INIS)

    Sundaram, A.K.; Hershkowitz, N.

    1992-01-01

    The modification of temperature-gradient-driven instabilities due to the presence of nonuniform radio-frequency fields near the ion cyclotron frequency is investigated in the linear regime. Employing the fluid theory, it is shown that the induced field line compression caused by ion cyclotron range of frequencies (ICRF) fields makes the net parallel compressibility positive, and thus provides a stabilizing influence on the ion-temperature-gradient-driven mode for an appropriately tailored profile of radio-frequency (rf) pressure. Concomitantly, the radial ponderomotive force generates an additional contribution via coupling between the perturbed fluid motion and the equilibrium ponderomotive force and this effect plays the role of dissipation to enhance or decrease the growth of temperature-gradient-driven modes depending upon the sign of rf pressure gradients. For decreased growth of temperature-gradient-driven instabilities, the plasma density gradients and rf pressure gradients must have opposite signs while enhancement in growth arises when both gradients have the same sign. Finally, the kinetic effects associated with these modes are briefly discussed

  12. Cyclotrons at the Institute of Physical and Chemical Research

    International Nuclear Information System (INIS)

    Imamura, Masashi.

    1989-01-01

    In this article the destruction by American forces, during World War II, of the Japanese cyclotrons and the subsequent construction of new cyclotrons at the Institute of Physical and Chemical Research, Japan is described. Their use for biological and medical radiation chemistry studies is summarized. (UK)

  13. Lower-hybrid absorption at the ion cyclotron harmonics

    International Nuclear Information System (INIS)

    Puri, S.

    1975-01-01

    In the presence of magnetic field gradients, the lower-hybrid wave can be absorbed through linear collisionless damping at the location of cyclotron or cyclotron harmonic resonances acting as singular turning points in the path of the advancing wave-front. (Auth.)

  14. A radioisotope production cyclotron designed to minimize dose

    International Nuclear Information System (INIS)

    Szlavik, F.F.; Moritz, L.E.

    1992-01-01

    This paper describes a radioisotope production cyclotron which has been designed to minimize the dose to personnel during operation and maintenance. The design incorporates lessons learned from the operation of a CP42 cyclotron and has resulted in a reduction of the dose by a factor of more than 10. (author)

  15. Calculation of particle dynamics in CI-10 cyclotron

    International Nuclear Information System (INIS)

    Samsonov, E.V.; Karamysheva, G.A.; Vorozhtsov, S.B.

    1999-01-01

    The calculations of beam dynamic characteristics of High-Intensity Cyclotron-Injector CI-10 for deuteron beam of 15 MeV energy are presented. Analytical estimations of space charge effects are given. In order to increase the intensity of the accelerator beam some ideas about the cyclotron design modification are given too. (author)

  16. First results of beam generation test for JAERI AVF cyclotron

    International Nuclear Information System (INIS)

    Tachikawa, T.; Hayashi, Y.; Ishii, K.

    1992-01-01

    The performance of JAERI AVF cyclotron was investigated with several kinds of ions in the wide energy range. The 90 MeV protons of 10 μA intensity was successfully extracted for the first time by the model 930 cyclotron. The feature of beam chopping system is also presented. (author)

  17. Resonance cones below the ion cyclotron frequency: theory and experiment

    International Nuclear Information System (INIS)

    Bellan, P.

    1976-03-01

    The resonance cones existing below the ion cyclotron frequency, ω/sub c/sub i//, are shown, theoretically and experimentally, to be the asymptotes of hyperbolic constant-phase surfaces of low-frequency ion acoustic waves. Above ω/sub c/sub i// the surfaces transform into ellipses that are related to the electrostatic ion cyclotron waves and ion acoustic waves

  18. Computer modeling of magnetic structure for IC-35 cyclotron

    International Nuclear Information System (INIS)

    Alenitskij, Yu.G.; Morozov, N.A.

    1998-01-01

    An extensive series of calculations has been carried out in order to design the magnetic structure of the IC-35 cyclotron for radioisotope production. The calculations were carried out by 2-D POISCR code. The average magnetic field and its variation were produced with the help of two different calculation models. The parameters of the cyclotron magnetic system are presented

  19. Relativistic gravitational instabilities

    International Nuclear Information System (INIS)

    Schutz, B.F.

    1987-01-01

    The purpose of these lectures is to review and explain what is known about the stability of relativistic stars and black holes, with particular emphases on two instabilities which are due entirely to relativistic effects. The first of these is the post-Newtonian pulsational instability discovered independently by Chandrasekhar (1964) and Fowler (1964). This effectively ruled out the then-popular supermassive star model for quasars, and it sets a limit to the central density of white dwarfs. The second instability was also discovered by Chandrasekhar (1970): the gravitational wave induced instability. This sets an upper bound on the rotation rate of neutron stars, which is near that of the millisecond pulsar PSR 1937+214, and which is beginning to constrain the equation of state of neutron matter. 111 references, 5 figures

  20. Character of decay instability

    International Nuclear Information System (INIS)

    Polovin, R.V.; Demutskii, V.P.

    1981-01-01

    If the initial wave is unstable in the upper half plane Im ω>0 and there are no branch points of the quasiwave number, or if waves traveling in the same direction coalesce at a branch point, the instability is convective. On the other hand, if a branch point k(ω) does exist in the upper half-plane Im ω>0, and not all the waves that merge at this point travel in the same direction, the instability is absolute. A Green's function that describes the evolution of the perturbations of the initial wave in space and in time is constructed. The growth rates of the decay instability of the harmonics are determined. The produced waves are richer in harmonics than the initial waves. It is shown that the decay instability of an Alfven wave is absolute

  1. Spondylolisthesis and Posterior Instability

    International Nuclear Information System (INIS)

    Niggemann, P.; Beyer, H.K.; Frey, H.; Grosskurth, D.; Simons, P.; Kuchta, J.

    2009-01-01

    We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI

  2. Spondylolisthesis and Posterior Instability

    Energy Technology Data Exchange (ETDEWEB)

    Niggemann, P.; Beyer, H.K.; Frey, H.; Grosskurth, D. (Privatpraxis fuer Upright MRT, Koeln (Germany)); Simons, P.; Kuchta, J. (Media Park Klinik, Koeln (Germany))

    2009-04-15

    We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.

  3. Fabrication of beam diagnostic components for Superconducting Cyclotron at Kolkata

    International Nuclear Information System (INIS)

    Roy, S.; Bhattacharya, S.; Das, T.; Bhattacharyya, T.K.; Pal, S.; Pal, G.; Mallik, C.; Bhandari, R.K.

    2009-01-01

    The viewer probe and main probe are used for determining the position and current of charged particles as it is accelerated inside the superconducting cyclotron. The viewer probe is used to visually observe the shape of the charged particle beam inside the cyclotron with the help of a borescope. The main probe measures the distribution of charged particles. The viewer probe and main probe are bellow sealed. They can be positioned with an accuracy of 0.5 mm at different radii within the superconducting cyclotron. M9 slit is placed after the exit flange of the cyclotron. It determines the position of the beam leaving the cyclotron. The beam line has slits, faraday cup, beam viewers, collimators, etc. for beam diagnostics. This paper presents the mechanical design and details of beam diagnostic components. (author)

  4. New superconducting cyclotron driven scanning proton therapy systems

    International Nuclear Information System (INIS)

    Klein, Hans-Udo; Baumgarten, Christian; Geisler, Andreas; Heese, Juergen; Hobl, Achim; Krischel, Detlef; Schillo, Michael; Schmidt, Stefan; Timmer, Jan

    2005-01-01

    Since one and a half decades ACCEL is investing in development and engineering of state of the art particle-therapy systems. A new medical superconducting 250 MeV proton cyclotron with special focus on the present and future beam requirements of fast scanning treatment systems has been designed. The first new ACCEL medical proton cyclotron is under commissioning at PSI for their PROSCAN proton therapy facility having undergone successful factory tests especially of the closed loop cryomagnetic system. The second cyclotron is part of ACCEL's integrated proton therapy system for Europe's first clinical center, RPTC in Munich. The cyclotron, the energy selection system, the beamline as well as the four gantries and patient positioners have been installed. The scanning system and major parts of the control software have already been tested. We will report on the concept of ACCEL's superconducting cyclotron driven scanning proton therapy systems and the current status of the commissioning work at PSI and RPTC

  5. Operation of the Karlsruhe Isochronous Cyclotron in 1975

    International Nuclear Information System (INIS)

    Schulz, F.; Schweickert, H.

    1976-06-01

    The operation of the Karlsruhe Isochronous Cyclotron in 1975 is briefly surveyed. The main reasons for a very short period for maintenance, repair and installation, and several additional efforts to improve the reliability of the accelerator installation, are discussed. The status and the results of several technical developments for the cyclotron are described: 1) the axial injection system; 2) computer aided cyclotron operation; 3) ion source development; 4) capacitive current measurement at the external beam; 5) new correction coils for the cyclotron; 6) improvement of the neutron time-of-flight spectrometer. As there is an increasing interest in using this type of accelerator for research in fields other than nuclear physics, it was felt appropriate to present short surveys on investigations at our cyclotron in 1975 in the fields of: 1) solid state physics; 2) engineering; 3) materials research; 4) nuclear medicine; 5) nuclear chemistry. (orig.) [de

  6. A new generation of medical cyclotrons for the 90's

    International Nuclear Information System (INIS)

    Milton, B.F.

    1995-08-01

    Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in 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 indicates 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. Existing and potential markets for these cyclotrons will be presented. They will also discuss the possibility of systems capable of extracted energies up to 150 MeV and extracted beam currents of up to 2.0 mA

  7. A new generation of medical cyclotrons for the 90's

    International Nuclear Information System (INIS)

    Milton, B.F.

    1995-08-01

    Cyclotrons continue to be efficient accelerators for use in radio-isotope production. In recent years, developments in 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 indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology as they relate to the new generation of commercial cyclotrons. Existing and potential markets for these cyclotrons will be presented. We will also discuss the possibility of systems capable of extracted energies up to 150 MeV and extracted beam currents of up to 2.0 mA. (author)

  8. U-2g0 cyclotron operational experience and improvement

    International Nuclear Information System (INIS)

    Gigal, B.N.; Gul'bekyan, G.G.; Kozlov, S.I.; Oganesyan, R.Ts.

    1983-01-01

    Brief description of main syste's of the U-200 isochronous 2-m cyclotron put into opera ion in 1968 is given and its operational characteristics a e presented. The cyclotron is used for conducting inve tigations in the field of nuclear physics. Ions from d uterium to argon have been accelerated in the cyclotro'. Annual time of target irradiation constitutes 2000-4000. The specific features of the cyclotron are: high l vel of a magnetic field (of about 20 kOe), possibili y of acceleration of ions with different mass-to-charge ratio a low correcting winding power, simple and high-e fective beam extraction by the method of charge exchange on a thin target allowing to vary smoothly energy of extracted ons. An experience in the U-200 cyclotron development and o eration is used as the basis for designing and choosing basic parameters of the U-200P, U-250, U-400 heavy ion cyclotrons

  9. Streaming gravity mode instability

    International Nuclear Information System (INIS)

    Wang Shui.

    1989-05-01

    In this paper, we study the stability of a current sheet with a sheared flow in a gravitational field which is perpendicular to the magnetic field and plasma flow. This mixing mode caused by a combined role of the sheared flow and gravity is named the streaming gravity mode instability. The conditions of this mode instability are discussed for an ideal four-layer model in the incompressible limit. (author). 5 refs

  10. Status report on RIKEN Ring Cyclotron

    International Nuclear Information System (INIS)

    Yano, Y.

    1988-01-01

    This paper gives a status report on RIKEN Ring Cyclotron (RRC), successfully commissioned on December 16, 1986. The routine operation of RRC began in April, 1987, and was made until March 1988. April and May were devoted to the machine studies, and beams were delivered to the experiments from the end of May. Seven kinds of ion species from carbon to copper were used for the nuclear physics and atomic physics experiments during these one-year runs. High quality beams with transverse emittances less than 10 mm mrad, energy spread of approximately 0.1% and pulse width less than 300 psec were extracted. Since the middle of March, 1988, RRC has been shut down for extending the beam transfer lines and installing the various experimental setups. Next experimental program will start in July, 1988. The initial operational status of RRC is described as well as the running construction program of the new injector, a K70 AVF cyclotron with an external ECR ion source

  11. Electron cyclotron heating calculations for ATF

    International Nuclear Information System (INIS)

    Goldfinger, R.C.; Batchelor, D.B.

    1986-03-01

    The RAYS geometrical optics code has been used to calculate electron cyclotron wave propagation and heating in the Advanced Toroidal Facility (ATF) device under construction at Oak Ridge National Laboratory (ORNL). The intent of this work is to predict the outcome of various heating scenarios and to give guidance in designing an optimum heating system. Particular attention is paid to the effects of wave polarization and antenna location. We investigate first and second harmonic cyclotron heating with the parameters predicted for steady-state ATF operation. We also simulate the effect of wall reflections by calculating a uniform, isotropic flux of power radiating from the wall. These results, combined with the first-pass calculations, give a qualitative picture of the heat deposition profiles. From these results we identify the compromises that represent the optimum heating strategies for the ATF model considered here. Our basic conclusions are that second harmonic heating with the extraordinary mode (X-mode) gives the best result, with fundamental ordinary mode (O-mode) heating being slightly less efficient. Assuming the antenna location is restricted to the low magnetic field side, the antenna should be placed at phi = 0 0 (the toroidal angle where the helical coils are at the sides) for fundamental heating and at phi = 15 0 (where the helical coils are at the top and bottom) for second harmonic heating. These recommendations come directly from the ray tracing results as well as from a theoretical identification of the relevant factors affecting the heating

  12. Acceleration of tritons with a compact cyclotron

    International Nuclear Information System (INIS)

    Wegmann, H.; Huenges, E.; Muthig, H.; Moringa, H.

    1981-01-01

    With the compact cyclotron at the Faculty of Physics of the Technical University of Munich, tritons have been accelerated to an energy of 7 MeV. A safe and reliable operation of the gas supply for the ion source was obtained by a new tritium storage system. A quantity of 1500 Ci tritium is stored by two special Zr-Al getter pumps in a non-gaseous phase. The tritium can be released in well-defined amounts by heating the getter material. During triton acceleration the pressure in the cyclotron vacuum chamber is maintained only by a large titanium sputter-ion pump, thus forming a closed vacuum system without any exhaust of tritium contaminated gas. Any tritium contaminations in the air can be detected by an extremely sensitive tritium monitoring system. The triton beam with a maximum intensity of 30 μA has been used so far to produce neutron-rich radioisotopes such as 28 Mg, 43 K, or 72 Zn, which are successfully applied in tracer techniques in the studies of biological systems. (orig.)

  13. Cyclotron Resonances in Electron Cloud Dynamics

    International Nuclear Information System (INIS)

    Celata, C.M.; Furman, M.A.; Vay, J.L.; Grote, D.P.; Ng, J.T.; Pivi, M.F.; Wang, L.F.

    2009-01-01

    A new set of resonances for electron cloud dynamics in the presence of a magnetic field has been found. For short beam bunch lengths and low magnetic fields where l b c , (l b = bunch duration, ω c = non-relativistic cyclotron frequency) resonances between the bunch frequency and harmonics of the cyclotron frequency cause an increase in the electron cloud density in narrow ranges of magnetic field near the resonances. For ILC parameters the increase in the density is up to a factor ∼ 3, and the spatial distribution of the electrons is broader near resonances, lacking the well-defined density 'stripes' of multipactoring found for non-resonant cases. Simulations with the 2D computer code POSINST, as well as a single-particle tracking code, were used to elucidate the physics of the dynamics. The resonances are expected to affect the electron cloud dynamics in the fringe fields of conventional lattice magnets and in wigglers, where the magnetic fields are low. Results of the simulations, the reason for the bunch-length dependence, and details of the dynamics will be discussed

  14. Visual assistance system for cyclotron operation

    International Nuclear Information System (INIS)

    Okamura, Tetsuya; Tachikawa, Toshiki; Murakami, Tohru.

    1994-01-01

    A computer-based operation system for a cyclotron which assists operators has been developed. It is the operation assistance system depending on visual sense to indicate beam parameters to operators. First, the mental model of operators at the time of beam adjustment was analyzed, and it was presumed to be composed of five partial mental models, that is, beam behavior model, feasible setting region model, parameter sensitivity model, parameter interrelation model and status map model. Next, three visual interfaces were developed. Beam trajectory is rapidly calculated and graphically displayed whenever operators change parameters. Feasible setting regions (FSR) for parameters that satisfy the beam acceptance criteria of a cyclotron are indicated. The distribution of beam current values which are the quantity for evaluating adjustment is indicated as search history. Finally, for evaluating the system effectiveness, the search time required to reach the optimum conditions was measured. In addition, the system usability was evaluated by written questionnaires. The result of experiment showed the reduction of search time by about 65%. The written questionnaires survey showed the operators highly evaluate system usability. (K.I.)

  15. Genomic instability and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Little, John B [Harvard School of Public Health, Boston, MA 02115 (United States)

    2003-06-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  16. Genomic instability and radiation

    International Nuclear Information System (INIS)

    Little, John B

    2003-01-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  17. Cyclotron Production of Technetium-99m

    Science.gov (United States)

    Gagnon, Katherine M.

    Technetium-99m (99mTc) has emerged as the most widely used radionuclide in medicine and is currently obtained from a 99Mo/ 99mTc generator system. At present, there are only a handful of ageing reactors worldwide capable of producing large quantities of the parent isotope, 99Mo, and owing to the ever growing shutdown periods for maintenance and repair of these ageing reactors, the reliable supply 99mTc has been compromised in recent years. With an interest in alternative strategies for producing this key medical isotope, this thesis focuses on several technical challenges related to the direct cyclotron production of 99mTc via the 100Mo(p,2n)99mTc reaction. In addition to evaluating the 100Mo(p,2n)99mTc and 100Mo(p,x)99Mo reactions, this work presented the first experimental evaluation of the 100Mo(p,2n) 99gTc excitation function in the range of 8-18 MeV. Thick target calculations suggested that large quantities of cyclotron-produced 99mTc may be possible. For example, a 6 hr irradiation at 500 μA with an energy window of 18→10 MeV is expected to yield 1.15 TBq of 99mTc. The level of coproduced 99gTc contaminant was found to be on par with the current 99Mo/99mTc generator standard eluted with a 24 hr frequency. Highly enriched 100Mo was required as the target material for 99mTc production and a process for recycling of this expensive material is presented. An 87% recovery yield is reported, including metallic target preparation, irradiation, 99mTc extraction, molybdate isolation, and finally hydrogen reduction to the metal. Further improvements are expected with additional optimization experiments. A method for forming structurally stable metallic molybdenum targets has also been developed. These targets are capable of withstanding more than a kilowatt of beam power and the reliable production and extraction of Curie quantities of 99mTc has been demonstrated. With the end-goal of using the cyclotron-produced 99mTc clinically, the quality of the cyclotron

  18. Curvature-driven instabilities in the Elmo Bumpy Torus (EBT)

    International Nuclear Information System (INIS)

    Abe, H.; Spong, D.A.; Antonsen, T.M. Jr.; Tsang, K.T.; Nguyen, K.T.

    1982-01-01

    Curvature-driven instabilities are analyzed for an EBT configuration which consists of plasma interacting with a hot electron ring whose drift frequencies are larger than the growth rates predicted from conventional magnetohydrodynamic (MHD) theory. Stability criteria are obtained for five possible modes: the conventional hot electron interchange, a high-frequency hot electron interchange (at frequencies greater than the ion-cyclotron frequency), a compressional instability, a background plasma interchange, and an interacting pressure-driven interchange. A wide parameter regime for stable operation is found, which, however, severely deteriorates for a band of intermediate mode numbers. Finite Larmor radius effects can eliminate this deterioration; moreover, all short-wavelength curvature-driven modes are stabilized if the hot electron Larmor radius rho/sub h/ satisfies (kappa/sub perpendicular/rho/sub h/) 2 > 2Δ/[Rβ/sub h/(1 + P'/sub parallel//P'/sub perpendicular/)], where kappa/sub perpendicular/ is the transverse wavenumber, Δ is the ring half-width, R is the mid-plane radius of curvature, β/sub h/ is the hot electron beta value, and P' is the pressure gradient. Resonant wave-particle instabilities predicted by a new low frequency variational principle show that a variety of remnant instabilities may still persist

  19. Implementation of a computer-controlled monitoring system at the Princeton AVF Cyclotron

    International Nuclear Information System (INIS)

    Moore, W.H.

    1984-01-01

    Stability in the parameters of the beams from cyclotrons is often crucial to the experiments laboratories perform. For example, when running a high-resolution experiment with Princeton's QDDD Spectrograph, there are 42 magnetic elements between the ion source and the detector. Instability or drift in any of these elements can easily nullify the sophisticated dispersion matching and kinematic correction that make such experiments possible with machines. At the Princeton Cyclotron they have purchased a commercial computer-controlled measurement system and interfaced it to 20 elements of their beamline. While this project is still far from complete, the authors have satisfied two of the conditions that must be met for such a system to be useful. These are, firstly, that measurements can be made under the conditions of a working laboratory to 1 part in 100,000, and secondly that the results can be presented in a form useful both to the experimenter concerned with the quality of his data and to the technical staff who must maintain and develop the equipment

  20. Modelling ion cyclotron emission from KSTAR tokamak and LHD helical device plasmas

    Science.gov (United States)

    Dendy, Richard; Chapman, Ben; Reman, Bernard; Chapman, Sandra; Akiyama, Tsuyoshi; Yun, Gunsu

    2017-10-01

    New high quality measurements of ion cyclotron emission (ICE) from KSTAR and LHD greatly extend the scope and diversity of plasma conditions under which ICE is observed. Variables include the origin (fusion reactions or neutral beam injection) and energy (sub- or super-Alfvénic) of the minority energetic ions that drive ICE; the composition of the bulk plasma (hydrogen or deuterium) which supports the modes excited; plasma density in the emitting region, and the timescale on which it changes; and toroidal magnetic field geometry (tokamak or helical device). Future exploitation of ICE as a diagnostic for energetic ion populations in JET D-T plasmas and in ITER rests on quantitative understanding of the physics of the emission. This is tested and extended by current KSTAR and LHD measurements of ICE. We report progress on direct numerical simulation using full orbit ion kinetic codes that solve the Maxwell-Lorentz equations for hundreds of millions of particles. In the saturated regime, these simulations yield excited field spectra that correspond directly to the measured ICE spectra under diverse KSTAR and LHD regimes. At early times, comparison of simulation outputs with linear analytical theory confirms the magnetoacoustic cyclotron instability as the basic driver of ICE. Supported by RCUK Energy Programme Grant EP/P012450/1, NRF Korea Grant 2014M1A7A1A03029881, NIFS budget ULHH029 and Euratom.

  1. Ion-Flow-Induced Excitation of Electrostatic Cyclotron Mode in Magnetized Dusty Plasma

    Science.gov (United States)

    Bezbaruah, P.; Das, N.

    2018-05-01

    The stability of electrostatic cyclotron mode is investigated in a flowing magnetized dusty plasma in the presence of strong ion-neutral collisions. In the high magnetic field limit, when the dust magnetization becomes important, it is expected that the collective behavior of magnetized dust grains suspended in the near-sheath region substantially influences the dispersion properties of electrostatic modes. The growth/damping of the collective excitation is significantly controlled by such parameters as the ion-neutral collision frequency, Mach number, and magnetic field strength. In our case, the explicit dependence of the Mach number on the magnetic field and collision frequency has been taken into account and possible implications on the stability of the mode is analyzed. Streaming instability of cyclotron modes may be important to understand issues related to the interaction mechanism between dust grains and other associated phenomena like Coulomb crystallization, phase behavior, transport properties, etc., in the relatively strong magnetic field limit, which is currently accessible in the DPD (Kiel University) and MDPX (PSL, Auburn University) experiments.

  2. High harmonic ion cyclotron heating in DIII-D: Beam ion absorption and sawtooth stabilization

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Fredrickson, E.D.; Mau, T.K.; Petty, C.C.; Pinsker, R.I.; Porkolab, M.; Rice, B.W.

    1999-01-01

    Combined neutral beam injection and fast wave heating at the fourth cyclotron harmonic produce an energetic deuterium beam ion tail in the DIII-D tokamak. When the concentration of thermal hydrogen exceeds ∼ 5%, the beam ion absorption is suppressed in favour of second harmonic hydrogen absorption. As theoretically expected, the beam absorption increases with beam ion gyro-radius; also, central absorption at the fifth harmonic is weaker than central absorption at the fourth harmonic. For central heating at the fourth harmonic, an energetic, perpendicular, beam population forms inside the q = 1 surface. The beam ion tail transiently stabilizes the sawtooth instability but destabilizes toroidicity induced Alfven eigenmodes (TAEs). Saturation of the central heating correlates with the onset of the TAEs. Continued expansion of the q = 1 radius eventually precipitates a sawtooth crash; complete magnetic reconnection is observed. (author)

  3. Amplification of electromagnetic ion cyclotron waves along a wave path in the Earth's multicomponent magnetosphere

    International Nuclear Information System (INIS)

    Hu, Y.D.; Fraser, B.J.; Olson, J.V.

    1990-01-01

    In this report, the authors consider the amplification of electromagnetic ion cyclotron waves along a geomagnetic field line in the multicomponent magnetosphere, assuming that the waves propagate parallel to the background magnetic field. The find it is possible for the ring-current protons (energy ∼ 10-100 keV), which supply the free energy to stimulate the waves, to resonate with the waves not only in the equatorial region but also off the equator. An instability, caused by a thermal anisotropy, may occur in separated regions on and/or off the equator. The positions of the source regions along the wave path depend on the concentration of cold heavy ion species. The significant off-equator source regions may be located at geomagnetic latitudes where the waves, with frequencies greater than the He + gyrofrequency on the equator, are in a local He + pass band

  4. Influence of Bernstein modes on the efficiency of electron cyclotron resonance x-ray source

    International Nuclear Information System (INIS)

    Andreev, V. V.; Nikitin, G.V.; Savanovich, V.Yu.; Umnov, A.M.; Elizarov, L.I.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-01-01

    The article considers the factors influencing the temperature of hot electron component in an electron cyclotron resonance (ECR) x-ray source. In such sources the electron heating occurs often due to extraordinary electromagnetic wave propagating perpendicularly to the magnetic field. In this case the possibility of the absorption of Bernstein modes is regarded as an additional mechanism of electron heating. The Bernstein modes in an ECR x-ray source can arise due to either linear transformation or parametric instability of external transversal wave. The article briefly reviews also the further experiments which will be carried out to study the influence of Bernstein modes on the increase of hot electron temperature and consequently of x-ray emission

  5. Magnetic field related mechanical tolerances for the proposed Chalk River superconducting heavy-ion cyclotron

    International Nuclear Information System (INIS)

    Heighway, E.A.; Chaplin, K.R.

    1977-11-01

    A four sector azimuthally varying field cyclotron with superconducting main coils has been proposed as a heavy-ion post-accelerator for the Chalk River MP Tandem van de Graaff. The radial profile of the average axial field will be variable using movable steel trim rods. The field errors due to coil, trim rod and flutter pole imperfections are calculated. Those considered are errors in the axial field, first and second azimuthal harmonic axial fields, transverse field and first azimuthal harmonic transverse field. Such fields induce phase slip, axial or radial coherent oscillations and can result in axial or radial beam instability. The allowed imperfections (tolerances) required to retain stability and maintain acceptably small coherent oscillation amplitudes are calculated. (author)

  6. A Proton-Cyclotron Wave Storm Generated by Unstable Proton Distribution Functions in the Solar Wind

    Science.gov (United States)

    Wicks, R. T.; Alexander, R. L.; Stevens, M.; Wilson, L. B., III; Moya, P. S.; Vinas, A.; Jian, L. K.; Roberts, D. A.; O’Modhrain, S.; Gilbert, J. A.; hide

    2016-01-01

    We use audification of 0.092 seconds cadence magnetometer data from the Wind spacecraft to identify waves with amplitudes greater than 0.1 nanoteslas near the ion gyrofrequency (approximately 0.1 hertz) with duration longer than 1 hour during 2008. We present one of the most common types of event for a case study and find it to be a proton-cyclotron wave storm, coinciding with highly radial magnetic field and a suprathermal proton beam close in density to the core distribution itself. Using linear Vlasov analysis, we conclude that the long-duration, large-amplitude waves are generated by the instability of the proton distribution function. The origin of the beam is unknown, but the radial field period is found in the trailing edge of a fast solar wind stream and resembles other events thought to be caused by magnetic field footpoint motion or interchange reconnection between coronal holes and closed field lines in the corona.

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

    Science.gov (United States)

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

    1992-01-01

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

  8. Comparative Study of the Axial and Azimuthal Bunching Mechanisms in Electromagnetic Cyclotron Instabilities.

    Science.gov (United States)

    1977-09-01

    role in the criterion and, hence, should not be a factor in the justification of a nonrelativistic treatment. Regimes of validity of nonrelativistic models are defined, however. Applications to gyroton experiments are discussed.

  9. Compact superconducting cyclotron C400 for hadron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jongen, Y.; Abs, M.; Blondin, A.; Kleeven, W.; Zaremba, S.; Vandeplassche, D. [IBA, Chemin du Cyclotron 3, B-1348 Louvain-la-Neuve (Belgium); Aleksandrov, V.; Gursky, S.; Karamyshev, O. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Karamysheva, G., E-mail: gkaram@nu.jinr.r [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation); Kazarinov, N.; Kostromin, S.; Morozov, N.; Samsonov, E.; Shirkov, G.; Shevtsov, V.; Syresin, E.; Tuzikov, A. [JINR, Joliot-Curie 6, 141980 Dubna, Moscow region (Russian Federation)

    2010-12-01

    The compact superconducting isochronous cyclotron C400 has been designed by the IBA-JINR collaboration. It will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for cancer treatment. The cyclotron construction is started this year within the framework of the Archade project (Caen, France). {sup 12}C{sup 6+} and {sup 4}He{sup 2+} ions will be accelerated to 400 MeV/uu energy and extracted by the electrostatic deflector, H{sub 2}{sup +} ions will be accelerated to the energy of 265 MeV/uu and extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts of the cyclotron will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located below the cyclotron. The main parameters of the cyclotron, its design, the current status of the development work on the cyclotron systems are presented.

  10. Cyclotron Development and Technical Aspects on Accelerator Based Laboratory Development

    International Nuclear Information System (INIS)

    Sunarhadijoso

    2000-01-01

    BATAN is planning to establish an accelerator-based laboratory at P3TM Yogyakarta as an effort in the development and use of accelerator technology for improving industrial performance and public welfare. This paper reviews several aspects of cyclotron technology and describes the combination of a linear accelerator - cyclotron system as an alternative to be considered in the planing of the laboratory. The progress of cyclotron technology is discussed covering three generations, i.e. conventional cyclotron, synchrocyclotron and AVF cyclotron generations. The planning should not consider the accelerator application for radioisotope production because it is established in Serpong with the existing negative ion cyclotron. The proposed facility at P3TM may comprise two linear accelerators coupled with a positive ion cyclotron of synchrocyclotron generation. In fact, the attachment of the synchrocyclotron unit is flexible and it can be installed subsequently if the higher energy particle beam, which can not be produced by the linear accelerators, is extremely needed. Some technical aspects related to ion beam application, building construction and infrastructure, human resources, and specification of function test are discussed for additional information in the implementation of the planning. (author)

  11. Survey on radionuclide producing using cyclotron method in Malaysia

    International Nuclear Information System (INIS)

    Mohd Fadli Mohammad Noh

    2008-01-01

    This research discuss about basic design and systems of medical cyclotron that Malaysia currently have, its applications in radionuclide production and upcoming technologies of cyclotron. Surveys have been carried out on cyclotron facilities at Hospital Putrajaya and Wijaya International Medical Center, WIMC as well as reactor facility at Malaysia Nuclear Agency. The sources in this research also involves on-line and library searches. Information obtained are recorded, categorized, synthesized and discussed. systems of cyclotron of Hospital Putrajaya are further discussed in details. Based from the surveys carried out, it is found out that cyclotron facilities both in Hospital Putrajaya and WIMC only produce ( 18 F)FDG with radioactivity of 18 F produced in 2007 are 16479 mCi and 92546 mCi respectively. Survey also revealed that radioisotope production at Nuclear Malaysia has had its operation been ceased. A new radiopharmaceutical, namely CHOL is suggested to be synthesized by both facilities as a new PET tracer. Latest developments concerning technologies of cyclotron as well as other accelerators such as laser for future medical accelerator, prospect of boron neutron capture and the potential of hadron therapy in Malaysia are discussed here. Radioisotope production in Malaysia is expected to keep booming in future due to increase in usage of PET techniques and the construction of more compact, easy to handle and less costly cyclotrons. (author)

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

    International Nuclear Information System (INIS)

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

    1992-01-01

    Pc 2 electromagnetic ion cyclotron waves at 0.1 waves at 0.1 Hz, near the oxygen cyclotron frequency, have been observed by ISEE 1 and 2 between L = 7.6 and 5.8 on an inbound near-equatorial pass in the dusk sector. The waves occurred in a thick plasmapause of width ∼ 1.5 R E and penetrated ∼1 R E into the plasmasphere. Wave onset was accompanied by significant increases in the thermal (0-100 eV) He + and the warm (0.1-16 keV/e) O + and He + heavy ion populations. The most intense waves (8 nT) were observed in the outer plasmasphere where convection drift velocities (E x B)/B 2 were largest and the Alfven velocity was a minimum. Wave polarization is predominantly left-handed with propagation almost parallel to the ambient magnetic field, and the spectral slot and polarization reversal predicted by cold plasma propagation theory are identified in the wave data. Poynting fluxes calculated during the first 15 min of the event show wave energy propagation directions both parallel and antiparallel to the field. Computations of the experimental wave spectra during the passage through the plasmapause show that the spectral slots relate to local plasma parameters, possibly suggesting an ion cyclotron wave growth source near the spacecraft. A regular wave packet structure seen over the first 30 min of the event may be attributed to the modulation of this energy source by the Pc 5 waves seen at the same time. Overall, the results are considered an example of an electromagnetic ion cyclotron wave-particle interaction occurring during the outer plasmasphere refilling process at the time of the substorm recovery phase

  13. Present status of device controls and hardware interfaces for the RCNP ring cyclotron

    International Nuclear Information System (INIS)

    Yamazaki, T.; Tamura, K.; Hosono, K.

    1994-01-01

    Since the first proton beam from the injector AVF cyclotron was injected to the ring cyclotron in 1991, the computer control system has been used for the beam acceleration of the ring cyclotron. Some device control modules have been updated, and computer configuration has been changed in 1992. Total control system performs basic facilities almost satisfactory under actual cyclotron operation. (author)

  14. Plasma physics and instabilities

    International Nuclear Information System (INIS)

    Lashmore-Davies, C.N.

    1981-01-01

    These lectures procide an introduction to the theory of plasmas and their instabilities. Starting from the Bogoliubov, Born, Green, Kirkwood, and Yvon (BBGKY) hierarchy of kinetic equations, the additional concept of self-consistent fields leads to the fundamental Vlasov equation and hence to the warm two-fluid model and the one-fluid MHD, or cold, model. The properties of small-amplitude waves in magnetized (and unmagnetized) plasmas, and the instabilities to which they give rise, are described in some detail, and a complete chapter is devoted to Landau damping. The linear theory of plasma instabilities is illustrated by the current-driven electrostatic kind, with descriptions of the Penrose criterion and the energy principle of ideal MHD. There is a brief account of the application of feedback control. The non-linear theory is represented by three examples: quasi-linear velocity-space instabilities, three-wave instabilities, and the stability of an arbitrarily largeamplitude wave in a plasma. (orig.)

  15. Electromagnetic Ion Cyclotron Waves in the Helium Branch Induced by Multiple Electromagnetic Ion Cyclotron Triggered Emissions

    Science.gov (United States)

    Shoji, M.; Omura, Y.; Grison, B.; Pickett, J. S.; Dandouras, I. S.; Engebretson, M. J.

    2011-12-01

    Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

  16. A study of parametric instability in a harmonic gyrotron: Designs of third harmonic gyrotrons at 94 GHz and 210 GHz

    International Nuclear Information System (INIS)

    Saraph, G.P.; Antonsen, T.M. Jr.; Nusinovich, G.S.; Levush, B.

    1995-01-01

    Mode competition can present a major hurdle in achieving stable, efficient operation of a gyrotron at the cyclotron harmonics. A type of mode interaction in which three modes at different cyclotron harmonics are parametrically coupled together is analyzed here. This coupling can lead to parametric excitation or suppression of a mode; cyclic mode hopping; or the coexistence of three modes. Simulation results are presented for the parametric instability involving modes at the fundamental, second harmonic, and third harmonic of the cyclotron frequency. It is shown that the parametric excitation can lead to stable, efficient operation of a high-power gyrotron at the third harmonic. Based on this phenomenon, two practical designs are presented here for the third harmonic operation at 94 and 210 GHz. copyright 1995 American Institute of Physics

  17. Analytic descriptions of ion cyclotron absorption

    International Nuclear Information System (INIS)

    Bers, A.; Francis, G.; Fuchs, V.; Lashmore-Davies, C.N.; Ram, A.K.

    1987-05-01

    Analysis of energy propagation and absorption in ion-cyclotron heating of tokamak plasmas has relied on numerical solutions of fourth (and sixth) order differential equations for slab models of the plasma (poloidal) cross section. Realistic two-dimensional and fully toroidal geometry analyses would become quite unwieldy. It is shown here that the analysis of the slab model can be simplified considerably. A first-order differential equation is shown to describe the transmission coefficient for the fast wave, and it is solved analytically. A second order differential equation is shown to adequately describe both transmission and reflection. Conditions for ion absorption or mode conversion are derived. Including toroidal effects in propagation, conditions for electron absorption on the mode-converted ion-Bernstein waves are also described analytically

  18. Ion cyclotron emission by spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Da Costa, O [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Gresillon, D [Ecole Polytechnique, 91 - Palaiseau (France). Lab. de Physique des Milieux Ionises

    1994-07-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs.

  19. In-house cyclotron and nuclear medicine

    International Nuclear Information System (INIS)

    Tateno, Yukio; Shishido, Fumio; Yamazaki, Toshiro

    1982-01-01

    In-house cyclotron produced radioisotopes and positron computed tomography provide a unique technique which gives cross-sectional bodyimages of various kinds of physiological activities of living human body. Applications of the technique to clinical study might throw a new light on the etiologically unknown disorders of human central nervous system and etc. However, some difficulties should be settled before the establishment of this technique as an useful research and diagnostic tool. One of them was spatial resolution of positron computed tomography, and another was selection and development of really effective labeled compounds for the disease in question. A rotary positron emission computed tomography device was developed by our physicist team, and our chemist team developed various kinds of radiopharmaceuticals. Clinical applications of the technique started in our institute in November 1979, using the positron computed tomography machine named Positrologica I and the pharmaceuticals, 13sup( n h3, )11sup( C o and )18 F-2-fluoro-deoxy-glucose. (author)

  20. 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.

  1. Electron cyclotron resonance (ECR) ion sources

    International Nuclear Information System (INIS)

    Jongen, Y.

    1984-05-01

    Starting with the pioneering work of R. Geller and his group in Grenoble (France), at least 14 ECR sources have been built and tested during the last five years. Most of those sources have been extremely successful, providing intense, stable and reliable beams of highly charged ions for cyclotron injection or atomic physics research. However, some of the operational features of those sources disagreed with commonly accepted theories on ECR source operation. To explain the observed behavior of actual sources, it was found necessary to refine some of the crude ideas we had about ECR sources. Some of those new propositions are explained, and used to make some extrapolations on the possible future developments in ECR sources

  2. Particle acceleration by electromagnetic ion cyclotron turbulence

    International Nuclear Information System (INIS)

    Crew, G.B.; Chang, Tom

    1990-01-01

    The LF EM-turbulence which furnishes energy for the acceleration of ions in various regions of the earth's magnetosphere efficiently accomplishes its transfer of energy from waves to particles through ion cyclotron resonance (ICR) with the left-hand polarized component of the turbulence; the result of this interaction is a heating of the particle distribution. A general theoretical treatment of ICR heating in a weakly inhomogeneous magnetic geometry is presented, en route to a more detailed examination of auroral ion conics' formation. A substantial simplification of the analysis of the altitude-asymptotic form of the conic distribution is obtained via the similarity transformation introduced into the properties of the electric field spectral density and the earth's dipolar magnetic field. 60 refs

  3. Ion cyclotron emission by spontaneous emission

    International Nuclear Information System (INIS)

    Da Costa, O.; Gresillon, D.

    1994-01-01

    The goal of the study is to examine whether the spontaneous emission can account for ICE (ion cyclotron emission) experimental results, or part of them. A straightforward approach to plasma emission is chosen, investigating the near equilibrium wave radiation by gyrating ions, and thus building from the majority and fast fusion ions the plasma fluctuations and emission on the fast magnetoacoustic or compressional Alfven wave mode in the IC frequency range. Similarities with the ICE experiments are shown: the emission temperature in the presence of fast ions (even in a very small amount), the strong fast ion emission increase with the harmonic, the fine double-line splitting of each peak, the linear but not proportional increase of the peak width with the harmonic. 3 refs., 2 figs

  4. Ion cyclotron heating in TMX-U

    International Nuclear Information System (INIS)

    Dimonte, G.; Barter, J.; Romesser, T.; Molvik, A.W.; Cummins, W.F.; Falabella, S.; Poulsen, P.

    1987-01-01

    Ion cyclotron heating (ICH) is applied to TMX-U to improve the thermal barrier performance by reducing the passing ion collisionality. During its development, measurements of the antenna loading resistance, R p , and the absorption efficiency, η, were compared with calculations with the antenna design code ANTENA over a wide range of densities and frequencies. Good agreement in R p was obtained in the short wavelength slow wave regime but not for long wavelength fast waves because the experimental magnetic field gradients are not modelled in ANTENA. Similarly, η is much larger experimentally (40%) than in ANTENA (10%) due to the magnetic beach in TMX-U. In its application, ICH successfully decreased the passing ion collisionality tenfold but did not extend thermal barrier plugging to higher density, indicating that collisional barrier filling is not currently limiting TMX-U performance. (author). 23 refs, 23 figs

  5. Neutron radiography using a transportable superconducting cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D.A. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Hawkesworth, M.R. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Beynon, T.D. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Green, S. (School of Physics and Space Research, University of Birmingham, Birmingham, B15 2TT (United Kingdom)); Rogers, J.D. (Rolls-Royce, Derby (United Kingdom)); Allen, M.J. (Rolls-Royce, Derby (United Kingdom)); Plummer, H.C. (Rolls-Royce, MatEval, Derby (United Kingdom)); Boulding, N.J. (Oxford Instruments (United Kingdom)); Cox, M. (Oxford Instruments (United Kingdom)); McDougall, I. (Oxford Instruments (United Kingdom))

    1994-12-30

    A thermal neutron radiography system based on a compact 12 MeV superconducting proton cyclotron is described. Neutrons are generated using a thick beryllium target and moderated in high density polyethylene. Monte Carlo computer simulations have been used to model the neutron and photon transport in order to optimise the performance of the system. With proton beam currents in excess of 100 [mu]A, it can provide high thermal neutron fluxes with L/D ratios of between 50 and 300 for various applications. Both film and electronic imaging are used to produce radiographs. The electronic imaging system consists of a [sup 6]Li-loaded ZnS intensifier screen, and a low light CCD or SIT camera. High resolution images can be recorded and computer-controlled data processing, analysis and display are possible. ((orig.))

  6. Electron - cyclotron resonance heating and current drive

    International Nuclear Information System (INIS)

    Fidone, I.; Castejon, F.

    1992-01-01

    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

  7. Electron Cyclotron Resonances in Electron Cloud Dynamics

    International Nuclear Information System (INIS)

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

    2008-01-01

    We report a previously unknown resonance for electron cloud dynamics. The 2D simulation code 'POSINST' was used to study the electron cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. An electron equilibrium density enhancement of up to a factor of 3 was found at magnetic field values for which the bunch frequency is an integral multiple of the electron cyclotron frequency. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ∼(2 pi mec/(elb)), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics are discussed

  8. Auxiliary accelerating system for TRIUMF cyclotron

    International Nuclear Information System (INIS)

    Zach, M.; Fong, K.; Laxdal, R.; Mackenzie, G.H.; Pacak, V.; Pearson, J.; Richardson, J.R.; Stanford, G.; Worsham, R.

    1990-06-01

    A 92 MHz auxiliary accelerating cavity has been designed and manufactured for installation in the TRIUMF cyclotron. Operating at the fourth harmonic of the RF with a peak voltage of 150 kV, it almost doubles the present energy gain per turn in the 400-500 MeV range, and reduces by ∼50% the stripping loss of the H - beam. This significant improvement will allow a substantial increase in the extracted current above the present routine level of 150μA while maintaining the same levels of residual radioactivity. The system is completed and being commissioned. A description of the design and commissioning procedures is presented, and results of beam tests given. (Author) 7 refs., 5 figs

  9. Isochronization calculations for the Indiana University cyclotron

    International Nuclear Information System (INIS)

    Jones, W.P.

    1975-01-01

    A series of calculations using measured magnetic fields was performed to determine the optimal gradient coil currents for the wide range of operating conditions to be experienced by the Indiana University main stage cyclotron. Depending on the particle type to be accelerated and final energy desired, the required radial field increase varies from 0.5 percent to 22 percent. An iterative least squares fitting technique is used to minimize orbit time variations. For the acceleration of 200 MeV protons (330 revolutions, fourth harmonic), the maximum phase excursion is predicted to be less than two rf degrees. The technique used can be adapted to using measured phase histories to predict corrections to gradient coil currents. (auth)

  10. Magnetic field optimisation and orbit calculation for VEC superconducting cyclotron

    International Nuclear Information System (INIS)

    Debnath, J.; Dey, M.K.; Mallik, C.; Bhandari, R.K.

    2003-01-01

    At VECC, Kolkata preparations are underway to measure the magnetic field of the cyclotron. Also once the superconducting cyclotron is assembled prediction of beam related parameters will be a very important exercise to carry out. Considering this the beam behaviour in the cyclotron will be crucial to achieve these goals. The present paper deals with the efforts in this direction and using a test beam of He 1+ 20 MeV/n the trim coil currents, the tune variation and the (r,Pr) behaviour of the central trajectory

  11. Design features and operating characteristics of the MC-50 cyclotron

    International Nuclear Information System (INIS)

    Bak, Hae Ill; Bak, Joo Shik

    1989-01-01

    The MC-50 cyclotron at Korean Cancer Center Hospital is now operational for neutron therapy and medical radioisotope production. Design features, mechanical structures and operating characteristics of the MC-50 are described in this paper. Optimum operating condition for this cyclotron has been determined by the repetitive running, and the performances of the internal beam have been investigated through the measurements of intensity and spatial distribution of the internal beam as a function of the radius of the cyclotron. Routinely, the 40 μA of 50 MeV protons have been obtained at first Faraday cup with a extraction efficiency of 61%. (Author)

  12. Health physics aspects of the 1.5M cyclotron

    International Nuclear Information System (INIS)

    Song, W.J.; Du, H.L.; Wei, Z.Q.; Xia, X.S.; Zheng, H.Z.; Jiang, G.F.; Liu, Y.Y.

    1987-01-01

    The 1.5m cyclotron in Institute of Modern Physics, Academia Sinica had operated for about 20 years until 1984 then converted to 1.7m sector focusing cyclotron. In this period it mainly used for fast neutron physics, light ion induced nucleus reactions, radioisotope production and heavy ion reactions. The health physics performed on this cyclotron including personnel dose monitoring, area monitoring (radiation field, radioactive aerosol, surface contamination and activated components etc.), maintenance inspection, environment survey and waste disposal is presented in this paper

  13. Thermal Stabilization of Cryogenic System in Superconducting Cyclotron

    International Nuclear Information System (INIS)

    Shin, Seung Jae; Kim, Kyung Min; Cho, Hyung Hee; Hong, Bong Hwan; Kang, Joon Sun; Ahn, Dong Hyun

    2011-01-01

    Radiology has some useful applications for medical purpose. For cancer therapy, the superconducting cyclotron should generate heavy ion beams. It radiates heavy ion beams to cancer patients. In order to make cyclotron system stable, the cryogenic system which makes superconducting state should work constantly. However, radiation heat transfer of cryogenic system should be considered because liquid helium's boiling point is extremely low and there is huge temperature difference between the cryogenic system and ambient temperature. Accordingly, thermal analysis should be carried out. In this paper, the numerical analysis of the cryogenic system in practical superconducting cyclotron show temperature distribution and suggest the number of coolers using ANSYS Workbench program

  14. Improving cancer treatment with cyclotron produced radionuclides. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Larson, S.M.; Finn, R.D.

    1993-11-01

    This report describes our continuing long term goal of promoting nuclear medicine applications by improving the scientific basis for tumor diagnosis, treatment and treatment follow-up based on the use of cyclotron produced radiotracers in oncology. The program includes 3 interactive components: Radiochemistry/Cyclotron; Pharmacology; and Immunology. An essential strategy is as follows: novel radionuclides and radiotracers developed in the Radiochemistry/Cyclotron section will be employed in the Pharmacology and Immunology sections during the next year. The development of novel radionuclides and tracers is of course useful in and of itself, but their utility is greatly enhanced by the interaction with the immunology and pharmacology components of the program.

  15. Ion extraction in the cyclotron geometry

    International Nuclear Information System (INIS)

    Rodenburg, R.E.

    1985-01-01

    The detailed physics of ion beam extraction from a plasma column by intense sinusoidal radio frequency (rf) electric fields at the ion cyclotron frequency omega/sub ci/ and its harmonics is experimentally studied. Results describe the instantaneous relationship - within one rf period of approx. = 3009 nsec - between applied rf, the plasma response and the ions expelled by rf and plasma fields. Reflex discharges in H 2 , D 2 , and He with ion and electron densities greater than or equal to10 11 cm -3 are subjected to 0-5 kV zero-to-peak rf electric fields E vector and 0.65-9.00 kG background magnetic fields B 0 vector with E vector perpendicular to B 0 vector. Ion currents up to 200 μA are extracted. Nonperturbing optical diagnostics measure the relative amplitude and phase of instantaneous ion and electron density fluctuations induced by the rf during each rf cycle and the time variation of extracted ion bursts, the latter made possible by the use of a phosphor beam-stop. Detailed dependences on external electric and magnetic fields are reported. The plasma density fluctuations are in good agreement with the dispersion relation for electrostatic ion cyclotron waves (EICW), and the beam data show current enhancement at the second harmonic over that at the fundamental and evidence for a radically different mechanism for the rf-driven ion extraction process than conventional wisdom assumes. This work represents the first detailed, systematic study of the ac ion extraction process

  16. Fingerprints of dynamical instabilities

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Colonna, M.; Guarnera, A.

    1993-01-01

    It is explained why any reduced descriptions, such as mean field approximation, are stochastic in nature. It is shown that the introduction of this stochastic dynamics leads to a predictive theory in a statistical sens whatever the individual trajectories are characterized by the occurrence of bifurcations, instabilities or phase transitions. Concerning nuclear matter, the spinodal instability is discussed. In such a critical situation, the possibility to replace the stochastic part of the collision integral in the Boltzmann-Langevin model by the numerical noise associated with the finite number of test particles in ordinary BUU treatment is studied. It is shown that the fingerprints of these instabilities are kept during the evolution because of the relatively long recombination time compared with the typical time scales imposed by the Coulomb repulsion and the possible collective expansion. (author) 5 refs., 12 figs

  17. Instability and star evolution

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.

    1981-01-01

    The observational data are discussed which testify that the phenomena of dynamical instability of stars and stellar systems are definite manifestations of their evolution. The study of these phenomena has shown that the instability is a regular phase of stellar evolution. It has resulted in the recognition of the most important regularities of the process of star formation concerning its nature. This became possible due to the discovery in 1947 of stellar associations in our Galaxy. The results of the study of the dynamical instability of stellar associations contradict the predictions of classical hypothesis of stellar condensation. These data supplied a basis for a new hypothesis on the formation of stars and nebulae by the decay of superdense protostars [ru

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

    International Nuclear Information System (INIS)

    Ono, Masayuki.

    1993-05-01

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

  19. Causes of genome instability

    DEFF Research Database (Denmark)

    Langie, Sabine A S; Koppen, Gudrun; Desaulniers, Daniel

    2015-01-01

    function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make......Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus...

  20. Instabilities and nonequilibrium structures

    International Nuclear Information System (INIS)

    Tirapegui, E.; Villarroel, D.

    1987-01-01

    Physical systems can be studied both near to and far from equilibrium where instabilities appear. The behaviour in these two regions is reviewed in this book, from both the theoretical and application points of view. The influence of noise in these situations is an essential feature which cannot be ignored. It is therefore discussed using phenomenological and theoretical approaches for the numerous problems which still remain in the field. This volume should appeal to mathematicians and physicists interested in the areas of instability, bifurcation theory, dynamical systems, pattern formation, nonequilibrium structures and statistical mechanics. (Auth.)

  1. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  2. Progress on Electron Cyclotron Heating Experiments in LHD

    International Nuclear Information System (INIS)

    Shimozuma, T.; Kubo, S.; Yoshimura, Y.; Igami, H.; Nagasaki, K.; Notake, T.; Inagaki, S.; Ito, S.; Kobayashi, S.; Mizuno, Y.; Takita, Y.; Ohkubo, K.; Saito, K.; Seki, T.; Kumazawa, R.; Watari, T.; Mutoh, T.

    2005-01-01

    Electron cyclotron resonance heating (ECH) is a powerful heating method because of its well-controlled local heating and high deposition power density. Together with the development of high power long pulse gyrotrons, ECH becomes one of the major heating scenarios to control electron temperature and current profiles for the improved plasma confinement and suppression of some magneto-hydro-dainamic (MHD) instabilities in both tokamaks and stellarators [1]. In the Large Helical Device (LHD), ECH has been worked as a method of plasma initiation and electron heating. The ECH system has been improved with respect to each experimental campaign. In the recent campaign, nine gyrotrons were operated reliably and steadily. As a diagnostic objective, a modulated ECH (MECH) was injected together with main ECH power. A Fourier analysis of the induced heat wave gave useful information of not only the heat transport in the plasmas but also precise power deposition layer [2]. Several kinds of ECH experiment were performed by using this flexible ECH system. In LHD, electron ITB formation have been observed by using strongly focused ECH in the plasma core [3].Two different kinds of improved confinement were realized depending on the direction of tangentially injected NBI. NBI beam driven currents modify the profiles of the rotational transform 2 ro and the existence low order rational surfaces, 2 = 0.5 in special, affects the difference of appearance of the improved confinement states. The MECH method was used to investigate the internal structure of the thermal diffusion in such plasmas [4]. Another important role of the MECH is the precise determination of the ECH power deposition. Shift of the deposition location by changing an injection polarization in the electron Bernstein wave (EBW) heating was clearly demonstrated by the MECH method. Electron cyclotron current drive (ECCD) experiments were proceeded by using a flexible antenna system, which had wide scanning range in both

  3. Buneman instability and Pierce instability in a collisionless bounded plasma

    International Nuclear Information System (INIS)

    Iizuka, Satoru; Saeki, Koichi; Sato, Noriyoshi; Hatta, Yoshisuke

    1983-01-01

    A systematic experiment is performed on the Buneman instability and the Pierce instability in a bounded plasma consisting of beam electrons and stationary ions. Current fluctuations are confirmed to be induced by the Buneman instability. On the other hand, the Pierce instability gives rise to a current limitation. The phenomena are well explained by Mikhailovskii's theory taking account of ion motion in a bounded plasma. (author)

  4. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 23

    Energy Technology Data Exchange (ETDEWEB)

    1967-10-09

    Progress is reported in the design, installation of various components of the cyclotron, including coils, magnets, rf system, and vacuum system. Also reported are measurements on magnets and rf components. (LEW)

  5. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 20

    Energy Technology Data Exchange (ETDEWEB)

    1967-06-30

    Progress is reported in the fabrication and testing of cyclotron components, including magnet system and rf system components. Work on vacuum components and instrumentation and control equipment is also reported. (LEW)

  6. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 32

    Energy Technology Data Exchange (ETDEWEB)

    1968-06-28

    Completion of magnet tests, followed by completion of installation of major cyclotron components, are reported. Intermediate level power tests of the rf system are also reported. Design and fabrication of the control system are reported to be under way. (LEW)

  7. Maryland University sectored isochronous cyclotron (MUSIC): Progress report No. 26

    Energy Technology Data Exchange (ETDEWEB)

    1968-01-17

    Progress is reported in the fabrication, installation, and testing of cyclotron components, including magnets and coils, rf components, vacuum and control equipment. Also reported are magnet and rf component measurements. (LEW)

  8. Cyclotron radiation by a multi-group method

    International Nuclear Information System (INIS)

    Chu, T.C.

    1980-01-01

    A multi-energy group technique is developed to study conditions under which cyclotron radiation emission can shift a Maxwellian electron distribution into a non-Maxwellian; and if the electron distribution is non-Maxwellian, to study the rate of cyclotron radiation emission as compared to that emitted by a Maxwellian having the same mean electron density and energy. The assumptions in this study are: the electrons should be in an isotropic medium and the magnetic field should be uniform. The multi-group technique is coupled into a multi-group Fokker-Planck computer code to study electron behavior under the influence of cyclotron radiation emission in a self-consistent fashion. Several non-Maxwellian distributions were simulated to compare their cyclotron emissions with the corresponding energy and number density equivalent Maxwellian distribtions

  9. Cryogenic system for VECC K500 superconducting cyclotron

    CERN Document Server

    Pal, G; Bhattacharyya, T K; Bhandari, R K

    2009-01-01

    VEC Centre, Kolkata in India is at an advanced stage of commissioning a K500 superconducting cyclotron. The superconducting coil of the magnet for cyclotron is cooled by liquid helium. Three liquid helium cooled cryopanels, placed inside the Dees of the radiofrequency system, maintain the vacuum in the acceleration region of the superconducting cyclotron. The cryogenic system for magnet for cyclotron has been tested by cooling the coil and energizing the magnet. The cryogenic system for cryopanels has also been tested. Heater and temperature sensor were placed on the liquid helium cold head for cryopanel. The temperature of the cold head was observed to be below 20 K upto a heat load of 11.7 watt.

  10. H-superconducting cyclotron for PET isotope production

    International Nuclear Information System (INIS)

    Smirnov, V.L.; Vorozhtsov, S.B.; Vincent, J.

    2014-01-01

    The scientific design of a 14-MeV H - compact superconducting cyclotron for producing of the 18 F and 13 N isotopes has been developed. Main requirements to the facility as a medical accelerator are met in the design. In particular, the main requirement for the cyclotron was the smallest possible size due to the superconducting magnet. The calculations show that the proposed cyclotron allows extracted beam intensity over 500 μA. To increase system reliability and production rates, an external H - ion source is applied. The choice of the cyclotron concept, design of the structure elements, calculation of the electromagnetic fields and beam dynamics from the ion source to the extraction system were performed.

  11. NORTICA—a new code for cyclotron analysis

    Science.gov (United States)

    Gorelov, D.; Johnson, D.; Marti, F.

    2001-12-01

    The new package NORTICA (Numerical ORbit Tracking In Cyclotrons with Analysis) of computer codes for beam dynamics simulations is under development at NSCL. The package was started as a replacement for the code MONSTER [1] developed in the laboratory in the past. The new codes are capable of beam dynamics simulations in both CCF (Coupled Cyclotron Facility) accelerators, the K500 and K1200 superconducting cyclotrons. The general purpose of this package is assisting in setting and tuning the cyclotrons taking into account the main field and extraction channel imperfections. The computer platform for the package is Alpha Station with UNIX operating system and X-Windows graphic interface. A multiple programming language approach was used in order to combine the reliability of the numerical algorithms developed over the long period of time in the laboratory and the friendliness of modern style user interface. This paper describes the capability and features of the codes in the present state.

  12. Cyclotrons for clinical and biomedical research with PET

    International Nuclear Information System (INIS)

    Wolf, A.P.

    1987-01-01

    The purpose of this commentary is to present some background material on cyclotrons and other particle accelerators particularly with a view toward the considerations behind acquiring and installing such a machine for purely clinical and/or biomedical research use

  13. Electron cyclotron resonance heating in a short cylindrical plasma ...

    Indian Academy of Sciences (India)

    The power mode conversion efficiency is estimated to be ... has also found application in electron cyclotron current drive (ECCD) in fusion ... (few GHz) of microwave sources, a small linear ECR plasma system can also serve ..... References.

  14. Development of baby cyclotron for PET in Korea

    International Nuclear Information System (INIS)

    Chai, J.S.; Kim, Y.S.; Hu, J.Y.; Shin, Y.C.; Yoon, M.H.

    2001-01-01

    Development of a 13 MeV cyclotron for Positron Emission Tomography (PET) has been in progress since April 1999 at the Korea Cancer Center Hospital (KCCH). The study has been carried out in a joint collaboration between KCCH and the Pohang University of Science and Technology (POSTECH). Increasing desire for an uninterrupted, reliable and timely supply of the isotopes to customers has prompted obtaining a dedicated 5-13 MeV cyclotron for PET applications and pursuing the purchase of another 30MeV medical cyclotron in the very near future. A decision has been made to design the PET cyclotron in Korea. This will not only ease the problems associated with maintenance during operation but also keep the door open for continuous upgrading of the machine in the future

  15. Remote machining and robotic welding in a proton cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, W; Mark, C

    1984-09-01

    Increasing residual radiation in the TRIUMF meson research facility cyclotron at the University of British Columbia has required development of a remotely operable industrial robot cutting and vacuum tight welding capabili

  16. The beam handling system of the Oslo Cyclotron

    International Nuclear Information System (INIS)

    Messelt, S.

    1985-11-01

    The beam optic system of the Oslo Cyclotron is described. A computer program for the calculation of optimal settings of quadropoles is presented. The reliability of the computer program is confirmed by experimental data

  17. Variable-Energy Cyclotron for Proton Therapy Application

    CERN Document Server

    Alenitsky, Yu G; Vorozhtsov, A S; Glazov, A A; Mytsyn, G V; Molokanov, A G; Onishchenko, L M

    2004-01-01

    The requirements to characteristics of the beams used for proton therapy are considered. The operation and proposed cyclotrons for proton therapy are briefly described. The technical decisions of creation of the cyclotron with energy variation in the range 70-230 MeV and with current up to 100 nA are estimated. Taking into account the fact, that the size and cost of the cyclotron are approximately determined by the maximum proton energy, it is realistically offered to limit the maximum proton energy to 190 MeV and to elaborate a cyclotron project with a warm winding of the magnet for acceleration of H^{-} ions. The energy of the extracted protons for each run is determined by a stripped target radius in the vacuum chamber of the accelerator, and the radiation dose field for the patient is created by the external devices using the developed techniques.

  18. Magnet design and test of positron emission tomography cyclotron

    International Nuclear Information System (INIS)

    Wei Tao; Yang Guojun; He Xiaozhong; Pang Jian; Zhao Liangchao; Zhang Kaizhi

    2012-01-01

    An 11 MeV H - compact cyclotron used for medical radioactive isotope production is under construction in Institute of Fluid Physics, CAEP. The cyclotron magnet adopts the design of small valley gaps and coulee structure which can provide high average magnetic field and strong focus ability. To achieve 5 × 10 -4 measuring accuracy, a magnetic field mapping system has been developed. After iterative correction using field measurement data, the total phase excursion of the cyclotron is within ± 9° and the first harmonic is less than 10 -3 T, which are all acceptable. Furthermore, the beam testing declares the successful construction of the cyclotron magnet. Besides, some magnetic field influence factors were discussed, including the magnetic field distortion and measurement error. (authors)

  19. Neutron field inside a PET Cyclotron vault room

    International Nuclear Information System (INIS)

    Vega C, H.R.; Mendez, R.; Iniguez, M.P.; Climent, J.M.; Penuelas, I.; Barquero, R.

    2006-01-01

    The neutron field around a Positron Emission Tomography cyclotron was investigated during 18 F radioisotope production with an 18 MeV proton beam. In this study the Ion Beam Application cyclotron, model Cyclone 18/9, was utilized. Measurements were carried out with a Bonner sphere neutron spectrometer with pairs of thermoluminescent dosemeters (TLD600 and TLD700) as thermal neutron detector. The TLDs readouts were utilized to unfold the neutron spectra at three different positions inside the cyclotron's vault room. With the spectra the Ambient dose equivalent was calculated. Neutron spectra unfolding were performed with the BUNKIUT code and the UTA4 response matrix. Neutron spectra were also determined by Monte Carlo calculations using a detailed model of cyclotron and vault room. (Author)

  20. Elbow joint instability

    DEFF Research Database (Denmark)

    Olsen, Bo Sanderhoff; Henriksen, M G; Søjbjerg, Jens Ole

    1994-01-01

    The effect of simultaneous ulnar and radial collateral ligament division on the kinematics of the elbow joint is studied in a cadaveric model. Severance of the anterior part of the ulnar collateral ligament and the annular ligament led to significant elbow joint instability in valgus and varus...

  1. Structural and Material Instability

    DEFF Research Database (Denmark)

    Cifuentes, Gustavo Cifuentes

    This work is a small contribution to the general problem of structural and material instability. In this work, the main subject is the analysis of cracking and failure of structural elements made from quasi-brittle materials like concrete. The analysis is made using the finite element method. Three...

  2. Agricultural Markets Instability

    NARCIS (Netherlands)

    Garrido, A.; Brümmer, B.; M'Barek, R.; Gielen-Meuwissen, M.P.M.; Morales-Opazo, C.

    2016-01-01

    Since the financial and food price crises of 2007, market instability has been a topic of major concern to agricultural economists and policy professionals. This volume provides an overview of the key issues surrounding food prices volatility, focusing primarily on drivers, long-term implications of

  3. Comment on critical instability

    International Nuclear Information System (INIS)

    King, S.F.; Suzuki, Mahiko

    1992-01-01

    We discuss the problem of the mass splitting between top and bottom quarks, within the context of Nambu-Jona-Lasinio type models involving top and bottom quark condensates. We interpret the phenomenon of 'critical instability' recently proposed to account for such a mass splitting as the fine-tuning of two vacuum expectation values in a composite two-Higgs doublet model. (orig.)

  4. On 'conflict of conservation laws in cyclotron radiation'

    International Nuclear Information System (INIS)

    White, S.M.; Parle, A.J.

    1985-01-01

    The authors reconsider the apparent conflict of conservation laws in cyclotron radiation, and show that earlier workers in this field did not correctly include the effects of radiation reaction in their calculations. When a 'recoil' term, calculated using relativistic quantum theory, is included in the angular momentum of the particle the conflict disappears. It is found that the guiding centre of the particle drifts outwards during cyclotron radiation. (author)

  5. The Medical Cyclotron Facility in RMC, Parel, BARC

    International Nuclear Information System (INIS)

    Gopalakrishna, Arjun; Banerjee, Sharmila

    2017-01-01

    The Medical Cyclotron Facility in Radiation Medicine Centre (RMC) is the first one of its kind, installed in 2002. "1"8F based radiotracers are produced in this facility on a routine basis for Positron Emission Tomography (PET), of in-house patients, as well as for supply to other nuclear medicine centers in Mumbai as well as Pune. The facility consists of the following sub parts - Cyclotron and support equipment; Radiochemistry synthesis laboratory; Quality control (QC) laboratory

  6. Channel of Axial Injection of DC-60 Cyclotron

    CERN Document Server

    Gikal, B N; Bogomolov, S L; Borisenko, A N; Borisov, O N; Gulbekyan, G G; Ivanenko, I A; Kalagin, I V; Kazacha, V I; Kazarinov, N Yu; Khabarov, M V; Lysukhin, S N; Melnikov, V N; Paschenko, S V; Tikhomirov, A V

    2006-01-01

    The design study and realization of the axial injection beam line of DC-60 cyclotron constructed at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research are given. The channel allows one to transport and to inject into the cyclotron ions with mass-to-charge ratio $A/Z$ being within interval A/Z=6-12 and kinetic energy up to 17 $Z/A$ keV/m.u.

  7. Ion-Beam-Excited Electrostatic Ion Cyclotron Waves

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1976-01-01

    Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field.......Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field....

  8. Parameters of the eigenellipsoid for separated sector cyclotrons

    International Nuclear Information System (INIS)

    Ferme, J.

    1989-01-01

    The analytical expressions of the elements of the beam matrix corresponding to the eigenellipsoid for a beam injected on an equilibrium orbit of a cyclotron are presented. The four dimensional phase space of the horizontal plane is only considered. Some restrictive hypotheses are made: there is no acceleration, and space charge effects are not taken into account. The beam matrix has been computed for the general case of spiraled sectors cyclotrons, and is valid for any given azimuth

  9. Process of a cyclotron modeling with SNOP program

    International Nuclear Information System (INIS)

    Smirnov, V.L.

    2015-01-01

    The description of the SNOP program developed in JINR and intended for numerical modeling of a beam dynamics in accelerating setups of cyclotron type is presented. The main methods of work with program components, and also stages of numerical modeling of a cyclotron, the analysis of the main characteristics of the accelerated bunch by means of the SNOP are given. The explanation of some algorithms and procedures used in the program is given. [ru

  10. Design study of electrostatic inflector in compact cyclotron injection system

    International Nuclear Information System (INIS)

    Zhang Tianjue; Fan Mingwu

    1996-01-01

    The beam dynamics behaviour in electrostatic inflector is investigated for a vertical type injection system to a compact cyclotron. The computer aided design and matching of the inflector are based on the simulation of computed beam orbit. Modeling and simulation are done on PC-486 to form a software package. The software package can be used to develop a new type cyclotron design combining with the software package CYCCAE developed by China Institute of Atomic Energy three years ago

  11. Wave trajectory and electron cyclotron heating in toroidal plasmas

    International Nuclear Information System (INIS)

    Maekawa, T.; Tanaka, S.; Terumichi, Y.; Hamada, Y.

    1977-12-01

    Wave trajectories propagating obliquely to magnetic field in toroidal plasmas are studied theoretically. Results show that the ordinary wave at appropriate incident angle is mode-converted to the extraordinary wave at first turning point and is further converted to the electron Bernstein wave during passing a loop or a hooked nail curve near second turning point and is cyclotron-damped away, resulting in local electron heating, before arriving at cyclotron resonance layer. (auth.)

  12. Mass measurements with the CIME cyclotron at GANIL

    International Nuclear Information System (INIS)

    Hornillos, M B Gomez; Chartier, M; Mittig, W; Blank, B; Chautard, F; Demonchy, C E; Gillibert, A; Jacquot, B; Jurado, B; Lecesne, N; Lepine-Szily, A; Orr, N A; Roussel-Chomaz, P; Savajols, H; Villari, A C C

    2005-01-01

    A new direct technique using the CIME cyclotron as a high-resolution mass spectrometer is being developed in order to measure the masses of exotic nuclei. Tests have been performed to check the feasibility of the method with a mixed beam of stable ions extracted from the SPIRAL ion source and injected into the CIME cyclotron. Preliminary results obtained with this new technique are presented and discussed

  13. Tracking Code for Microwave Instability

    International Nuclear Information System (INIS)

    Heifets, S.; SLAC

    2006-01-01

    To study microwave instability the tracking code is developed. For bench marking, results are compared with Oide-Yokoya results [1] for broad-band Q = 1 impedance. Results hint to two possible mechanisms determining the threshold of instability

  14. Instabilities in thin tunnel junctions

    International Nuclear Information System (INIS)

    Konkin, M.K.; Adler, J.G.

    1978-01-01

    Tunnel junctions prepared for inelastic electron tunneling spectroscopy are often plagued by instabilities in the 0-500-meV range. This paper relates the bias at which the instability occurs to the barrier thickness

  15. Stability and nonlinear dynamics of gyrotrons at cyclotron harmonics

    International Nuclear Information System (INIS)

    Saraph, G.P.; Nusinovich, G.S.; Antonsen, T.M. Jr.; Levush, B.

    1992-01-01

    Gyrotrons operating at higher harmonics of the cyclotron frequency can overcome the frequency limitations caused by achievable strength of the magnetic field. However, the excitation of modes at the fundamental frequency exhibit a major problem for stable operation of harmonic gyrotron at high power with high efficiency. Therefore the issues of stability of gyrotron operation at the cyclotron harmonics and nonlinear dynamics of mode interaction are of great importance. The results of the authors stability analysis and multimode simulation are presented here. A detailed nonlinear theory of steady state single mode operation at cyclotron harmonics has been presented previously, taking into account beam-wave coupling and nonlinear gain function at cyclotron harmonics. A set of equations describing low gain regime interaction of modes resonant at different cyclotron harmonics was studied before. The multifrequency time-dependent nonlinear analysis presented here is based on previous gyrotron studies and beam-wave interaction at cyclotron harmonics. The authors have determined the parameter space for stable single mode operation at the second harmonic. The nonlinear dynamics of mode evolution and mode interaction for a harmonic gyrotron is presented. A new nonlinear effect in which the parasite at the fundamental harmonic helps excite the operating mode at the second harmonic has been demonstrated

  16. Rf structure of superconducting cyclotron for therapy application

    International Nuclear Information System (INIS)

    Takekoshi, Hidekuni; Matsuki, Seishi; Mashiko, Katuo; Shikazono, Naomoto.

    1981-01-01

    Advantages of fast neutrons in therapeutical application are now widely recognized. Fast neutrons are generated by bombarding a thick beryllium target with high energy protons and deuterons. The AVF cyclotrons which deliver 50 MeV protons and 25 MeV deuterons are commonly used and are commercially available now. At the treatment usually rotational irradiation is taken to prevent an injury to normal tissue from the high LET effect of fast neutrons. The construction cost of both cyclotrons and isocentric irradiation installation are relatively high, so that the spread of neutron therapy is obstructed. A superconducting cyclotron for neutron therapy application was proposed by a Chalk River group. This low cost design allows the installation to be a dedicated facility located in a hospital, and small size allows installations of the complete cyclotron in a rotatable gantry. The design studies of the superconducting cyclotron based on this idea are going on at Kyoto University. The full scale model experiments for a rf structure of the cyclotron were carried out. (author)

  17. A mobile superconducting cyclotron for PET and neutron radiography

    International Nuclear Information System (INIS)

    Griffiths, R.

    1988-01-01

    The report addresses the development of a mobile superconducting cyclotron for PET (positron emission tomography) and neutron radiography. Proposals for an ultralight cyclotron were made by Finlan et al., who suggested a novel technique of utilising a superconducting magnet with RF acceleration and iron sectors contained within the room temperature bore of the magnet. Detailed design of a cyclotron based on this concept has progressed well at Oxford Instruments. The main design priorities were to minimise the weight and power consumption of the cyclotron. The cyclotron required a large amount of shielding to reduce either radiation background levels or stray magnetic field. Thus low background levels of radiation and magnetic field are key design criteria. The superconducting magnet has a mean field of 2.35 Tesla and a room temperature bore diameter of 500 mm. Three pairs of profiled iron sectors placed in the center of the warm bore of the magnet provide an azimuthally varying magnetic field. This permits the use of high beam currents with low background. A novel technique is incorporated to reduce the stray magnetic field and radiation from the cyclotron. The RF system consists of three pairs of resonators mounted within the warm bore of the magnet between the iron sectors. (Nogami, K.)

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

    Science.gov (United States)

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

    2014-02-01

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

  19. A 30 MeV H- cyclotron for isotope production

    International Nuclear Information System (INIS)

    Milton, B.F.; Dawson, R.; Erdman, K.L.

    1989-05-01

    Because of an expanding market for radioisotopes there is a need for a new generation of cyclotrons designed specifically for this purpose. TRIUMF is cooperating with a local industrial company in designing and constructing such a cyclotron. It will be a four sector H - cyclotron, exploiting the newly developed high brightness multicusp ion source. This source with H - current capability in excess of 5 mA makes feasible accelerated H - beam intensities of up to 500 μA. Beam extraction is by stripping to H + in a thin graphite foil. Extraction of two high-intensity beams, with energy variable from 15 to 30 MeV is planned. The use of an external ion source, provision of a good vacuum in the acceleration region, and the careful choice of materials for components in the median plane leads to a cyclotron that will have low activation and can be easily serviced in spite of the very high operating beam intensities. A design extension to 70 MeV using many of the design features of the 30 MeV cyclotron can be easily made. Such a machine with a good quality variable energy beam is a highly desirable source of protons for isotope production, injection into higher energy high intensity acceleration, injection into higher energy high intensity accelerators, and as an irradiation facility for ocular melanomas. Design of the 30 MeV cyclotron is well advanced and construction is in progress

  20. Two-point theory of current-driven ion-cyclotron turbulence

    International Nuclear Information System (INIS)

    Chiueh, T.; Diamond, P.H.

    1985-02-01

    An analytical theory of current-driven ion-cyclotron turbulenc which treats incoherent phase space density granulations (clumps) is presented. In contrast to previous investigations, attention is focused on the physically relevant regime of weak collective dissipation, where waves and clumps coexist. The threshold current for nonlinear instability is calculated, and is found to deviate from the linear threshold. A necessary condition for the existence of stationary wave-clump turbulence is derived, and shown to be analogous to the test particle model fluctuation-dissipation theorem result. The structure of three dimensional magnetized clumps is characterized. It is proposed that instability is saturated by collective dissipation due to ion-wave scattering. For this wave-clump turbulence regime, it is found that the fluctuation level (e psi/T/sub e/)/sub rms/ less than or equal to 0.1, and that the modification of anomalous resistivity to levels predicted by conventional nonlinear wave theories is moderate. It is also shown that, in marked contrast to the quasilinear prediction, ion heating significantly exceeds electron heating

  1. Commercial cyclotrons. Part I: Commercial cyclotrons in the energy range 10 30 MeV for isotope production

    Science.gov (United States)

    Papash, A. I.; Alenitsky, Yu. G.

    2008-07-01

    A survey of commercial cyclotrons for production of medical and industrial isotopes is presented. Compact isochronous cyclotrons which accelerate negative hydrogen ions in the energy range 10 30 MeV have been widely used over the last 25 years for production of medical isotopes and other applications. Different cyclotron models for the energy range 10 12 MeV with moderate beam intensity are used for production of 11C, 13N, 15O, and 18F isotopes widely applied in positron emission tomography. Commercial cyclotrons with high beam intensity are available on the market for production of most medical and industrial isotopes. In this work, the physical and technical parameters of different models are compared. Possibilities of improving performance and increasing intensity of H- beams up to 2 3 mA are discussed.

  2. Proceedings of the 12. Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Heating

    International Nuclear Information System (INIS)

    Giruzzi, Gerardo

    2003-01-01

    The 12. Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Heating was held in Aix-en-Provence (France) from 13 to 16 May 2002. The meeting was hosted by the Association Euratom-CEA sur la Fusion (CEA/Cadarache, France), with additional financial support from: - Region Provence-Alpes Cote d'Azur - The City of Aix-en-Provence - Communaute de l'Agglomeration du Pays d'Aix - Thales Electron Devices (France) - Alstom Magnets and Superconductors (France) - Spinner GmbH (Germany). The members of the local organizing committee were: G. Giruzzi, M. Lennholm, R. Magne and V. Poli, from CEA/Cadarache. The composition of the International Programme Committee was the following: M. Bornatici (Italy), A. Costley (ITER), E. de la Luna (Spain), G. Giruzzi (France), W. Kasparek (Germany), B. Lloyd (UK), J. Lohr (USA), K. Sakamoto (Japan). The subjects of the meeting were classified in four main topics: Electron Cyclotron Theory; Electron Cyclotron Emission; Electron Cyclotron Heating and Current Drive Experiments; Electron Cyclotron Technology. The results presented in these topics have been summarised in the closing session by E. Westerhof, A. Kraemer-Flecken, T. Goodman and G. Bosia, respectively. The workshop was attended by 85 participants from 18 countries, providing 10 invited talks, 30 oral presentations and 50 posters. The success of the workshop is mainly due to the amount and quality of their work and of their presentations. The generosity of the sponsors, the selection and advice work of the International Programme Committee, as well as the contribution of the chairmen and of the summary speakers should also be warmly acknowledged. The papers in this collection have been reproduced directly from the authors' manuscripts, provided either as camera-ready texts or as pdf files. The constraints on the papers lengths and formats have been kept to a minimum, on purpose. This series of workshops has now reached a good level of maturity, with well established

  3. Nonlinear evolution of MHD instabilities

    International Nuclear Information System (INIS)

    Bateman, G.; Hicks, H.R.; Wooten, J.W.; Dory, R.A.

    1975-01-01

    A 3-D nonlinear MHD computer code was used to study the time evolution of internal instabilities. Velocity vortex cells are observed to persist into the nonlinear evolution. Pressure and density profiles convect around these cells for a weak localized instability, or convect into the wall for a strong instability. (U.S.)

  4. Flute instability growth on a magnetized plasma column

    International Nuclear Information System (INIS)

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r i , where R is the Gaussian characteristic radius and r i is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation

  5. Electron cyclotron emission measurements during 28 GHz electron cyclotron resonance heating in Wendelstein WVII-A stellarator

    International Nuclear Information System (INIS)

    Hartfuss, H.J.; Gasparino, U.; Tutter, M.; Brakel, R.; Cattanei, G.; Dorst, D.; Elsner, A.; Engelhardt, K.; Erckmann, V.; Grieger, G.; Grigull, P.; Hacker, H.; Jaeckel, H.; Jaenicke, R.; Junker, J.; Kick, M.; Kroiss, H.; Kuehner, G.; Maassberg, H.; Mahn, C.; Mueller, G.; Ohlendorf, W.; Rau, F.; Renner, H.; Ringler, H.; Sardei, F.; Weller, A.; Wobig, H.; Wuersching, E.; Zippe, M.; Kasparek, W.; Mueller, G.A.; Raeuchle, E.; Schueller, P.G.; Schwoerer, K.; Thumm, M.

    1987-11-01

    Electron cyclotron emission measurements have been carried out on electron cyclotron resonance heated plasmas in the WENDELSTEIN VII-A Stellarator. Blackbody radiation from the thermalized plasma main body as well as radiation from a small amount of weakly relativistic suprathermal electrons has been detected. In addition sideband emission has been observed near the second harmonic of the heating line source. Harmonic generation and parametric wave decay at the upper hybrid layer may be a reasonable explanation. (orig.)

  6. Characterization of electron cyclotron resonance hydrogen plasmas

    International Nuclear Information System (INIS)

    Outten, C.A.

    1990-01-01

    Electron cyclotron resonance (ECR) plasmas yield low energy and high ion density plasmas. The characteristics downstream of an ECR hydrogen plasma were investigated as a function of microwave power and magnetic field. A fast-injection Langmuir probe and a carbon resistance probe were used to determine plasma potential (V p ), electron density (N e ), electron temperature (T e ), ion energy (T i ), and ion fluence. Langmuir probe results showed that at 17 cm downstream from the ECR chamber the plasma characteristics are approximately constant across the center 7 cm of the plasma for 50 Watts of absorbed power. These results gave V p = 30 ± 5 eV, N e = 1 x 10 8 cm -3 , and T e = 10--13 eV. In good agreement with the Langmuir probe results, carbon resistance probes have shown that T i ≤ 50 eV. Also, based on hydrogen chemical sputtering of carbon, the hydrogen (ion and energetic neutrals) fluence rate was determined to be 1 x 10 16 /cm 2 -sec. at a pressure of 1 x 10 -4 Torr and for 50 Watts of absorbed power. 19 refs

  7. Fourier transform ion cyclotron resonance mass spectrometry

    Science.gov (United States)

    Marshall, Alan G.

    1998-06-01

    As for Fourier transform infrared (FT-IR) interferometry and nuclear magnetic resonance (NMR) spectroscopy, the introduction of pulsed Fourier transform techniques revolutionized ion cyclotron resonance mass spectrometry: increased speed (factor of 10,000), increased sensitivity (factor of 100), increased mass resolution (factor of 10,000-an improvement not shared by the introduction of FT techniques to IR or NMR spectroscopy), increased mass range (factor of 500), and automated operation. FT-ICR mass spectrometry is the most versatile technique for unscrambling and quantifying ion-molecule reaction kinetics and equilibria in the absence of solvent (i.e., the gas phase). In addition, FT-ICR MS has the following analytically important features: speed (~1 second per spectrum); ultrahigh mass resolution and ultrahigh mass accuracy for analysis of mixtures and polymers; attomole sensitivity; MSn with one spectrometer, including two-dimensional FT/FT-ICR/MS; positive and/or negative ions; multiple ion sources (especially MALDI and electrospray); biomolecular molecular weight and sequencing; LC/MS; and single-molecule detection up to 108 Dalton. Here, some basic features and recent developments of FT-ICR mass spectrometry are reviewed, with applications ranging from crude oil to molecular biology.

  8. Inactivation of bacterial cells by cyclotron beams

    Energy Technology Data Exchange (ETDEWEB)

    Yatagai, F [Waseda Univ., Tokyo (Japan). School of Science and Engineering; Takahashi, T; Matsuyama, A

    1975-06-01

    B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r were bombarded with ..cap alpha..-particles and heavy ions of carbon, nitrogen and oxygen accelerated in the IPCR Cyclotron. The RBE versus LETsub(infinity) curve for B. subtilis spores showed a maximum peak at 120 keV/..mu..m, while those for E. coli Bsub(s-1) and E. coli B/r declined without any maximum as LETsub(infinity) values increased. In the region of ..cap alpha..-particles, the effective inactivation cross section (Ssub(eff)) for these three strains increased with increasing LETsub(infinity), and the rates of increase in Ssub(eff) in the LET region from --30 to --150 keV/..mu..m were 15.0, 1.5 and 2.5 times for B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r, respectively. In the case of B. subtilis spores, Ssub(eff) values for heavy ions were almost independent of their energies, but the other two strains showed a considerable dependence upon beam energy. The characteristic LET dependence of Ssub(eff) observed in this study was fairly well explained by the target theory based on microdose concept.

  9. The 200 MeV cyclotron facility

    International Nuclear Information System (INIS)

    1987-01-01

    Beams of protons with several different energies have now been successfully transported between the injector cyclotron SPC1 and the SSC. Some small modifications to the placement of steering magnets and diagnostic equipment have been made in the light of our operational experience, which should improve the ease of tuning this beamline. Proton beams up to 200 MeV in energy have been transported to the experimental areas, where experiments in nuclear physics have been successful conducted. Three of the experimental beamlines are now in operation. Beams of 66 MeV protons have also been transported to targets in the isotope production vault, without difficulty. Field mapping of the remaining quadrupoles on site has been completed. Installation of and alignment of magnets up to the beam swinger is also complete, although the beam tube itself, plus vacuum and diagnostic equipment must still be tackled. The beam swinger has been designed and detailed in the drawing office, and is now being manufactured locally. The beamline elements for the sepctrometer beamline remain to be purchased. A personal computer has been purchased for controlling the field-mapping equipment for the spectrometer magnets, which are being manufactured in this country. A number of computer programs have been written for conversion of calibrated quadrupole and dipole magnet field data to absolute current values for the control system. Other programs permit diagnostic measurements of beam profiles to be used to calculated the beam emittance, or to set steering magnets so that the beam is correctly aligned

  10. Electronic cyclotron radiation amplification in thermonuclear plasmas

    International Nuclear Information System (INIS)

    Ziebell, L.F.

    1983-01-01

    The amplified emission of electron cyclotron radiation near the fundamental frequency from an inhomogeneous, anisotropic plasma slab is investigated in a linear theory. Plasma polarization effects are consistently included. Expressions are developed in the WKB approximation for emission in the ordinary and the extraordinary modes, for propagation perpendicular to the magnetic field. Numerical results are given for the extraordinary mode, for which effects are strongest. For the case of a loss-cone-type electron momentum distribution, it is shown that the amplification is sensitively dependent on the ratio of parallel-to-perpendicular temperature and on inhomogeneities in the magnetic field. The dependence of the amplification on the distribution is further investigated by considering superpositions of loss-cone and Maxwellian components. It is show that the presence of a Maxwellian component in general reduces the emission relative to the pure loss-cone case, and situations occur in which a layer in the slab very effectively absorbs all the radiation amplified elsewhere. A peculiar behaviour of the refractive index, which occurs in the transition from the pure loss-cone to the pure Maxwellian case, is discussed. (author)

  11. Ferrite-guided cyclotron-resonance maser

    International Nuclear Information System (INIS)

    Jerby, Eli; Kesar, A.; Aharony, A.; Breitmeier, G.

    2002-01-01

    The concept of a cyclotron-resonance maser (CRM) with a ferrite loading incorporated in its waveguide is proposed. The CRM interaction occurs between the rotating electron beam and the em wave propagating along a longitudinally magnetized ferrite medium. The ferrite anisotropic permeability resembles the CRM susceptibility in many aspects, and particularly in their similar response to the axial magnetic field (the ferrite susceptibility can be regarded as a passive analog of the active CRM interaction). The ferrite loading slows down the phase velocity of the em wave and thus the axial (Weibel) mechanism of the CRM interaction dominates. The ferrite loading enables also a mechanism of spectral tunability for CRM's. The ferrite loading is proposed, therefore, as a useful ingredient for high-power CRM devices. A linear model of the combined ferrite-guided CRM interaction reveals its useful features. Future schemes may also incorporate ferrite sections functioning as isolators, gyrators, or phase shifters within the CRM device itself for selective suppression of backward waves and spurious oscillations, and for gain and efficiency enhancement

  12. Automation in irradiating target systems for cyclotrons

    International Nuclear Information System (INIS)

    Araujo, Sumair G.; Sciani, Valdir; Almeida, Rosemeire S.

    2000-01-01

    Nowadays, two cyclotron are being operated at IPEN-CNEN/SP: one model CV-28, capable of accelerating p, d, 3 He 4 and α, with energies of 24, 14, 36 and 28 MeV, respectively, and beam currents up to 30 μA; the other one, model cyclone 30, accelerates protons with energy of 30 MeV and currents up to 350 μ A. Both have the objective of irradiating targets both for radioisotope production for use in Nuclear Medicine, such as 67 Ga, 201 Tl, 111 In, 123 I, 18 F, and general research. The development of irradiating systems completely automatized was the objective of this work, always aiming to reduce the radiation exposition dose to the workers and to increasing the reliability of use of these systems, because very high activities are expected in these processes. In the automation, a Programmable Logical Controller (PLC) was used connected to a feedback net, to manage all the variables involved in the irradiation processes. The program of the PLC was developed using Simatic Step Seven (S7), Software from Siemens, where all the steps are supervised in screens at a microcomputer. The assembling and sequence of leading were developed using the software from Unisoft, that keeps the operator informed about the work being carried out, at any time. (author)

  13. Inactivation of bacterial cells by cyclotron beams

    International Nuclear Information System (INIS)

    Yatagai, Fumio; Takahashi, Tadashi; Matsuyama, Akira.

    1975-01-01

    B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r were bombarded with α-particles and heavy ions of carbon, nitrogen and oxygen accelerated in the IPCR Cyclotron. The RBE versus LETsub(infinity) curve for B. subtilis spores showed a maximum peak at 120 keV/μm, while those for E. coli Bsub(s-1) and E. coli B/r declined without any maximum as LETsub(infinity) values increased. In the region of α-particles, the effective inactivation cross section (Ssub(eff)) for these three strains increased with increasing LETsub(infinity), and the rates of increase in Ssub(eff) in the LET region from --30 to --150 keV/μm were 15.0, 1.5 and 2.5 times for B. subtilis spores, E. coli Bsub(s-1) and E. coli B/r, respectively. In the case of B. subtilis spores, Ssub(eff) values for heavy ions were almost independent of their energies, but the other two strains showed a considerable dependence upon beam energy. The characteristic LET dependence of Ssub(eff) observed in this study was fairly well explained by the target theory based on microdose concept. (auth.)

  14. Ion cyclotron system design for KSTAR tokamak

    International Nuclear Information System (INIS)

    Hong, B. G.; Hwang, C. K.; Jeong, S. H.; Yoony, J. S.; Bae, Y. D.; Kwak, J. G.; Ju, M. H.

    1998-05-01

    The KSTAR (Korean Superconducting Tokamak Advanced Research) tokamak (R=1.8 m, a=0.5 m, k=2, b=3.5T, I=2MA, t=300 s) is being constructed to do long-pulse, high-b, advanced-operating-mode fusion physics experiments. The ion cyclotron (IC) system (in conjunction with an 8-MW neutral beam and a 1.5-MW lower hybrid system) will provide heating and current drive capability for the machine. The IC system will deliver 6 MW of RF power to the plasma in the 25 to 60 MHz frequency range, using a single four-strap antenna mounted in a midplane port. It will be used for ion heating, fast-wave current drive (FWCD), and mode-conversion current drive (MCCD). The phasing between current straps in the antenna will be adjustable quickly during operation to provide the capability of changing the current-drive efficiency. This report describes the design of the IC system hardware: the electrical characteristics of the antenna and the matching system, the requirements on the power sources, and electrical analyses of the launcher. (author). 7 refs., 2 tabs., 40 figs

  15. Ion cyclotron system design for KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Hong, B. G.; Hwang, C. K.; Jeong, S. H.; Yoony, J. S.; Bae, Y. D.; Kwak, J. G.; Ju, M. H

    1998-05-01

    The KSTAR (Korean Superconducting Tokamak Advanced Research) tokamak (R=1.8 m, a=0.5 m, k=2, b=3.5T, I=2MA, t=300 s) is being constructed to do long-pulse, high-b, advanced-operating-mode fusion physics experiments. The ion cyclotron (IC) system (in conjunction with an 8-MW neutral beam and a 1.5-MW lower hybrid system) will provide heating and current drive capability for the machine. The IC system will deliver 6 MW of RF power to the plasma in the 25 to 60 MHz frequency range, using a single four-strap antenna mounted in a midplane port. It will be used for ion heating, fast-wave current drive (FWCD), and mode-conversion current drive (MCCD). The phasing between current straps in the antenna will be adjustable quickly during operation to provide the capability of changing the current-drive efficiency. This report describes the design of the IC system hardware: the electrical characteristics of the antenna and the matching system, the requirements on the power sources, and electrical analyses of the launcher. (author). 7 refs., 2 tabs., 40 figs.

  16. Electron cyclotron emission spectroscopy on thermonuclear plasmas

    International Nuclear Information System (INIS)

    Tubbing, B.J.D.

    1987-01-01

    Analysis of electron cyclotron emission (ECE) enables one to infer the radial profile of the electron temperature in tokamaks. The Dutch FOM institute for plasma physics has designed, built, installed and operated a grating polychromator for ECE measurements at JET. This thesis deals with a few instrumental aspects of this project and with applications of ECE measurements in tokamak physics studies. Ch. 3 and 4 deal with the wave transport in ECE systems. In Ch. 3 a method is developed to infer the mode conversion, which is a source for transmission losses, in a waveguide component from the antenna pattern of its exit aperture. In Ch. 4 the design and manufacture of the waveguide transition system to the grating polychromator are described. In Ch. 5 a method is reported for calibration of the spectrometers, based on the use of a microwave source which simulates a large area blackbody of very high temperature. The feasibility of the method is tested by applying it to two different ECE systems. In Ch. 6 a study of heat pulse propagation in tokamak plasma's, based on measurement of the electron temperature with the grating polychromator, is presented. 105 refs.; 48 figs.; 8 tabs

  17. Instabilities in strongly coupled plasmas

    CERN Document Server

    Kalman, G J

    2003-01-01

    The conventional Vlasov treatment of beam-plasma instabilities is inappropriate when the plasma is strongly coupled. In the strongly coupled liquid state, the strong correlations between the dust grains fundamentally affect the conditions for instability. In the crystalline state, the inherent anisotropy couples the longitudinal and transverse polarizations, and results in unstable excitations in both polarizations. We summarize analyses of resonant and non-resonant, as well as resistive instabilities. We consider both ion-dust streaming and dust beam-plasma instabilities. Strong coupling, in general, leads to an enhancement of the growth rates. In the crystalline phase, a resonant transverse instability can be excited.

  18. Orphans and political instability.

    Science.gov (United States)

    Breuning, Marijke; Ishiyama, John

    2011-01-01

    This study investigates the security implications of growing orphan populations, particularly in Sub-Saharan Africa. Little has been written about the security implications of this especially vulnerable group of children. Are growing orphan populations associated with increases in political instability as has been suggested? Using data from several sources, we employ regression analysis to test whether Sub-Saharan African countries with larger proportions of orphans and those with increasing orphan populations experience higher rates of political instability. We find that the increase in the orphan population is related to an increasing incidence of civil conflict, but do not find a similar relationship for the proportion of orphans. In addition, we find that the causes of orphanhood matter. We conclude that increases in orphan populations (rather than simple proportions) are destabilizing. We suggest possible avenues for mediating the security risks posed by growing orphan populations.

  19. A trickle instability

    Science.gov (United States)

    Bossa, Benjamin

    2005-11-01

    We address the problem of the free fall of a long, horizontal and narrow liquid layer squeezed in a vertical open Hele-Shaw cell. The layer destabilizes as it falls down, evolving into a series of liquid blobs linked together by thin bridges, which ultimately break, leaving the initially connex fluid layer as a set a disjointed drops. The mechanism of this instability is the onset of a vertical pressure gradient due to the curvature difference of the moving contact line between the advancing interface and the rear interface. This instability, whose growth rate scales with a non-trivial power of the capillary number, amplifies indifferently a broad band of wavenumbers because of the flat shape of its dispersion relation in the thin layer limit. We will finally comment on the nature of the final fragmentation process and drop size distributions.

  20. Instability and internet design

    Directory of Open Access Journals (Sweden)

    Sandra Braman

    2016-09-01

    Full Text Available Instability - unpredictable but constant change in one’s environment and the means with which one deals with it - has replaced convergence as the focal problem for telecommunications policy in general and internet policy in particular. Those who designed what we now call the internet during the first decade of the effort (1969-1979, who in essence served simultaneously as its policy-makers, developed techniques for coping with instability of value for network designers today and for those involved with any kind of large-scale sociotechnical infrastructure. Analysis of the technical document series that was medium for and record of that design process reveals coping techniques that began with defining the problem and went on to include conceptual labour, social practices, and technical approaches.

  1. Imaging of patellofemoral instability

    International Nuclear Information System (INIS)

    Waldt, S.; Rummeny, E.J.

    2012-01-01

    Patellofemoral instability remains a diagnostic and therapeutic challenge due to its multifactorial genesis. The purpose of imaging is to systematically analyze predisposing factors, such as trochlear dysplasia, patella alta, tibial tuberosity-trochlear groove (TT-TG) distance, rotational deformities of the lower limb and patellar tilt. In order to evaluate anatomical abnormalities with a sufficient diagnostic accuracy, standardized measurement methods and implementation of various imaging modalities are necessary. Diagnosis of acute and often overlooked lateral patellar dislocation can be established with magnetic resonance imaging (MRI) because of its characteristic patterns of injury. Damage to the medial patellofemoral ligament (MPFL) has a significance just as high as the predisposing risk factors in relation to the cause of chronic instability. (orig.) [de

  2. Linear waves and instabilities

    International Nuclear Information System (INIS)

    Bers, A.

    1975-01-01

    The electrodynamic equations for small-amplitude waves and their dispersion relation in a homogeneous plasma are outlined. For such waves, energy and momentum, and their flow and transformation, are described. Perturbation theory of waves is treated and applied to linear coupling of waves, and the resulting instabilities from such interactions between active and passive waves. Linear stability analysis in time and space is described where the time-asymptotic, time-space Green's function for an arbitrary dispersion relation is developed. The perturbation theory of waves is applied to nonlinear coupling, with particular emphasis on pump-driven interactions of waves. Details of the time--space evolution of instabilities due to coupling are given. (U.S.)

  3. Cosmic ray driven instability

    International Nuclear Information System (INIS)

    Dorfi, E.A.; Drury, L.O.

    1985-01-01

    The interaction between energetic charged particles and thermal plasma, which forms the basis of diffusive shock acceleration, leads also to interesting dynamical phenomena. For a compressional mode propagating in a system with homoeneous energetic particle pressure it is well known that friction with the energetic particles leads to damping. The linear theory of this effect has been analyzed in detail by Ptuskin. Not so obvious is that a non-uniform energetic particle pressure can in addition amplify compressional disturbances. If the pressure gradient is sufficiently steep this growth can dominate the frictional damping and lead to an instability. It is important to not that this effect results from the collective nature of the interaction between the energetic particles and the gas and is not connected with the Parker instability, nor with the resonant amplification of Alfven waves

  4. Instability in dynamic fracture

    Science.gov (United States)

    Fineberg, J.; Marder, M.

    1999-05-01

    The fracture of brittle amorphous materials is an especially challenging problem, because the way a large object shatters is intimately tied to details of cohesion at microscopic scales. This subject has been plagued by conceptual puzzles, and to make matters worse, experiments seemed to contradict the most firmly established theories. In this review, we will show that the theory and experiments fit within a coherent picture where dynamic instabilities of a crack tip play a crucial role. To accomplish this task, we first summarize the central results of linear elastic dynamic fracture mechanics, an elegant and powerful description of crack motion from the continuum perspective. We point out that this theory is unable to make predictions without additional input, information that must come either from experiment, or from other types of theories. We then proceed to discuss some of the most important experimental observations, and the methods that were used to obtain the them. Once the flux of energy to a crack tip passes a critical value, the crack becomes unstable, and it propagates in increasingly complicated ways. As a result, the crack cannot travel as quickly as theory had supposed, fracture surfaces become rough, it begins to branch and radiate sound, and the energy cost for crack motion increases considerably. All these phenomena are perfectly consistent with the continuum theory, but are not described by it. Therefore, we close the review with an account of theoretical and numerical work that attempts to explain the instabilities. Currently, the experimental understanding of crack tip instabilities in brittle amorphous materials is fairly detailed. We also have a detailed theoretical understanding of crack tip instabilities in crystals, reproducing qualitatively many features of the experiments, while numerical work is beginning to make the missing connections between experiment and theory.

  5. Adiabatic-drift-loss modification of the electromagnetic loss-cone instability for anisotropic plasma

    International Nuclear Information System (INIS)

    Juhl, B.; Treumann, R.A.

    1980-01-01

    Observation of the adiabatic behaviour of energetic particle pitch-angle distributions in the magnetosphere (Lyons, 1977, and others) in the past indicated the development of pronounced minima or drift-loss cones on the pitch-angle distributions centred at α approx.= 90 0 in connection with storm-time changes in magnetospheric convection and magnetic field. Using a model of a drift-modified loss-cone distribution (MLCD) of the butterfly type, the linear stability of electromagnetic whistler or ion-cyclotron waves propagating parallel to the magnetic field has been investigated. The instability is shown to be quenched at high frequencies ω 0 are identified as generating electromagnetic cyclotron waves near the marginally stable frequency ωsub(m). It is concluded that the absence of electromagnetic VLF and ELF noise during times when MLCD develops is the result of the shift of the unstable spectrum to low frequencies. (orig.)

  6. Relativistic centrifugal instability

    Science.gov (United States)

    Gourgouliatos, Konstantinos N.; Komissarov, Serguei S.

    2018-03-01

    Near the central engine, many astrophysical jets are expected to rotate about their axis. Further out they are expected to go through the processes of reconfinement and recollimation. In both these cases, the flow streams along a concave surface and hence, it is subject to the centrifugal force. It is well known that such flows may experience the centrifugal instability (CFI), to which there are many laboratory examples. The recent computer simulations of relativistic jets from active galactic nuclei undergoing the process of reconfinement show that in such jets CFI may dominate over the Kelvin-Helmholtz instability associated with velocity shear (Gourgouliatos & Komissarov). In this letter, we generalize the Rayleigh criterion for CFI in rotating fluids to relativistic flows using a heuristic analysis. We also present the results of computer simulations which support our analytic criterion for the case of an interface separating two uniformly rotating cylindrical flows. We discuss the difference between CFI and the Rayleigh-Taylor instability in flows with curved streamlines.

  7. Analyses of MHD instabilities

    International Nuclear Information System (INIS)

    Takeda, Tatsuoki

    1985-01-01

    In this article analyses of the MHD stabilities which govern the global behavior of a fusion plasma are described from the viewpoint of the numerical computation. First, we describe the high accuracy calculation of the MHD equilibrium and then the analysis of the linear MHD instability. The former is the basis of the stability analysis and the latter is closely related to the limiting beta value which is a very important theoretical issue of the tokamak research. To attain a stable tokamak plasma with good confinement property it is necessary to control or suppress disruptive instabilities. We, next, describe the nonlinear MHD instabilities which relate with the disruption phenomena. Lastly, we describe vectorization of the MHD codes. The above MHD codes for fusion plasma analyses are relatively simple though very time-consuming and parts of the codes which need a lot of CPU time concentrate on a small portion of the codes, moreover, the codes are usually used by the developers of the codes themselves, which make it comparatively easy to attain a high performance ratio on the vector processor. (author)

  8. Ion temperature gradient instability

    International Nuclear Information System (INIS)

    1989-01-01

    Anomalous ion thermal conductivity remains an open physics issue for the present generation of high temperature Tokamaks. It is generally believed to be due to Ion Temperature Gradient Instability (η i mode). However, it has been difficult, if not impossible to identify this instability and study the anomalous transport due to it, directly. Therefore the production and identification of the mode is pursued in the simpler and experimentally convenient configuration of the Columbia Linear Machine (CLM). CLM is a steady state machine which already has all the appropriate parameters, except η i . This parameter is being increased to the appropriate value of the order of 1 by 'feathering' a tungsten screen located between the plasma source and the experimental cell to flatten the density profile and appropriate redesign of heating antennas to steepen the ion temperature profile. Once the instability is produced and identified, a thorough study of the characteristics of the mode can be done via a wide range of variation of all the critical parameters: η i , parallel wavelength, etc

  9. A small low energy cyclotron for radioisotope measurements

    International Nuclear Information System (INIS)

    Bertsche, K.J.

    1989-11-01

    Direct detection of 14 C by accelerator mass spectrometry has proved to be a much more sensitive method for radiocarbon dating than the decay counting method invented earlier by Libby. A small cyclotron (the ''cyclotrino'') was proposed for direct detection of radiocarbon in 1980. This combined the suppression of background through the use of negative ions, which had been used effectively in tandem accelerators, with the high intrinsic mass resolution of a cyclotron. Development of a small electrostatically-focused cyclotron for use as a mass spectrometer was previously reported but the sensitivity needed for detection of 14 C at natural abundance was not achieved. The major contributions of this work are the integration of a high current external ion source with a small flat-field, electrostatically-focused cyclotron to comprise a system capable of measuring 14 C at natural levels, and the analysis of ion motion in such a cyclotron, including a detailed analysis of phase bunching and its effect on mass resolution. A high current cesium sputter negative ion source generates a beam of carbon ions which is pre-separated with a Wien filter and is transported to the cyclotron via a series of electrostatic lenses. Beam is injected radially into the cyclotron using electrostatic deflectors and an electrostatic mirror. Axial focusing is entirely electrostatic. A microchannel plate detector is used with a phase-grated output. In its present form the system is capable of improving the sensitivity of detecting 14 C in some biomedical experiments by a factor of 10 4 . Modifications are discussed which could bring about an additional factor of 100 in sensitivity, which is important for archaeological and geological applications. Possibilities for measurements of other isotopes, such as 3 H, and 10 Be, and 26 Al, are discussed. 70 refs

  10. Risk assessment of 30 MeV cyclotron facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Gyo Seong; Lee, Jin Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Chong Yeal [Dept. of Radiation Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

    2017-03-15

    A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce 18F, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fres and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a free. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI.

  11. Design of RF system for CYCIAE-230 superconducting cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Zhiguo, E-mail: bitbearAT@hotmail.com; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

    2017-05-11

    The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push–pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

  12. The PET / cyclotron facility at Putrajaya Hospital - an update

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib; Suzilawati Muhd Sarowi; Munira Shaikh Nasir; Zulkifli Mohamed Hashim

    2006-01-01

    Malaysia desire to have a cyclotron for nuclear medical use came into realisation recently with the establishment of a PET/Cyclotron Facility at Putrajaya Hospital. The testing and commissioning of the cyclotron, hot cells, QC equipment and PET/CT started on March 27, culminating in the first patient to be injected on May 10 2006. Three other patients were to be followed on May 15. The patients from both the Kuala Lumpur and Putrajaya Hospital were pre-selected by physicians from these hospitals. The 18 MeV cyclotron is capable of generating 16.4 MeV protons and 8.4 MeV deuterons. The cyclotron at Putrajaya has three targets (2 liquid and 1 gas) and is capable of producing 18 F-FDG and 18 F-DOPA. To complement this, the facility has 2 modules for FDG synthesis, 1 for F-DOPA and 1 for nucleophilic synthesis. The facility will be GMP compliant. For the first production for human use, the water-18 target was irradiated for 50 minutes at 20 mA to produce 1.3 Ci of F-18. At the end of synthesis, the activity of the FDG obtained was 600 mCi. The product was then injected to a 26-year-old female, with a suspected adenocarcinoma. (Author)

  13. Radiation protection problems by the operation of the cyclotron facility

    International Nuclear Information System (INIS)

    Durcik, M.; Nikodemova, D.

    1998-01-01

    The Cyclotron Center in Bratislava will consist of two cyclotrons. First - cyclotron DC-72 with maximal energy of 72 MV for protons for making experiments, for teaching process, for radioisotope production as 123 I and for neutron and proton therapy. Second - compact cyclotron with maximal proton energy of 18 MeV will be used for radioisotopes production for medical diagnosis as 1 *F (fluorodeoxyglucose), 81 Rb/ 81 Kr generator. This paper deals with the radiation protection problems by the operation of tis cyclotron facility as radiation protection of workers, monitoring plan, ventilation, safety lock and limitation and radiation monitoring. For proposed and continuing practices at the accelerator facility, the following general principles have to be fulfilled: (1) practices should produce sufficient benefit to offset the radiation detriment they case (justification); (2) the magnitude of the individual doses should be kept as low as achievable (optimization of protection); (3) individual exposures are subject to dose limits and some control of risk from potential exposures (dose and risk limits)

  14. Power deposition for ion cyclotron heating in large tokamaks

    International Nuclear Information System (INIS)

    Hellsten, T.; Villard, L.

    1988-01-01

    The power deposition profiles during minority ion cyclotron heating are analysed in large tokamaks by using the global, toroidal wave code LION. For tokamaks with large aspect ratio and with circular cross-section, the wave is focused on the magnetic axis and can be absorbed there by cyclotron absorption when the cyclotron resonance passes through the magnetic axis. The power deposition profile is then essentially determined by the Doppler broadening of the ion cyclotron resonance. For equilibria either non-circular or with a small aspect ratio the power deposition profile depends also on the strength of the damping. In this case the power deposition profile can be expressed as a sum of two power deposition profiles. One is related to the power absorbed in a single pass, and its shape is similar to that obtained for large aspect ratio and circular cross-section. The other profile is obtained by calculating the power deposition in the limit of weak damping, in which case the wave electric field is almost constant along the cyclotron resonance layer. A heuristic formula for the power deposition is given. The formula includes a number of calibration curves and functions which has been calculated with the LION code for JET relevant equilibria. The formula enables calculation of the power deposition profile in a simple way when the launched wave spectrum and damping coefficients are known. (author). 7 refs, 11 figs

  15. Design of RF system for CYCIAE-230 superconducting cyclotron

    Science.gov (United States)

    Yin, Zhiguo; Ji, Bin; Fu, Xiaoliang; Cao, Xuelong; Zhao, Zhenlu; Zhang, Tinajue

    2017-05-01

    The CYCIAE230 is a low-current, compact superconducting cyclotron designed for proton therapy. The Radio Frequency system consists of four RF cavities and applies second harmonic to accelerate beams. The driving power for the cavity system is estimated to be approximately 150 kW. The LLRF controller is a self-made device developed and tested at low power using a small-scale cavity model. In this paper, the resonator systems of an S.C. cyclotron in history are reviewed. Contrary to those RF systems, the cavities of the CYCIAE230 cyclotron connect two opposite dees. Two high-power RF windows are included in the system. Each window carries approximately 75 kW RF power from the driver to the cavities. Thus, the RF system for the CY-CIAE230 cyclotron is operated in driven push-pull mode. The two-way amplifier-coupler-cavity systems are operated with approximately the same amount of RF power but 180° out of phase compared with each other. The design, as well as the technical advantage and limitations of this operating mode, of the CYCIAE230 cyclotron RF system is analyzed.

  16. Cyclotron for industrial production of radioisotopes: relevants characteristics

    International Nuclear Information System (INIS)

    Lima, Wanderley de

    1997-01-01

    The industrial production of radioisotopes requests cyclotrons with easy maintenance services, high productivity and low operation costs. To obtain this performance the experts on the have achieved excellent results, taking advantage of modern resources in calculation and modeling. Only by the maximum exploitation of the azimutal variation of the magnetic field, a physical concept introduced in 1967 with the isocronous cyclotrons, it was possible to construct cyclotrons with only 30% of the electrical consumption required by the former cyclotrons. On the other hand, the acceleration of negative ions enable the 100% accelerated beam utilization, without internal energy dissipation, obtaining beam intensities up to 1mA in continuous running which represents an increased factor of 15. Other construction parameters were optimized aiming at reliability and reduction in the components activation. Concerning energy consumption and the beam intensity supplied, a present cyclotron with 30 MeV and 300μA of protons current is 15 times more efficient than its precedent. (author). 6 refs., 1 fig., 2 tabs

  17. Potential of cyclotron based accelerators for energy production and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Stammbach, T.; Adam, S.; Fitze, H.R. [Paul Scherrer Institute, Villigen (Switzerland)] [and others

    1995-10-01

    PSI operates a 590 MeV-cyclotron facility for high intensity proton beams for the production of intense beams of pions and muons. The facility, commissioned in 1974, has been partially upgraded and is now operated routinely at a beam current of 1 mA, which corresponds to a beam power of 0.6 MW. At this current, the beam losses in the cyclotron are about 0.02%. By the end of 1995 the authors expect to have 1.5 mA of protons. Extensive theoretical investigations on beam current limitations in isochronous cyclotrons were undertaken. They show that the longitudinal space charge effects dominate. Based on their experience the authors present a preliminary design of a cyclotron scheme that could produce a 10 MW beam as a driver for an {open_quotes}energy amplifier{close_quotes} as proposed by C. Rubbia and his collaborators. The expected efficiency for the conversion of AC into beam power would be about 50% (for the RF-systems only). The beam losses in the cyclotron are expected to be a few {mu}A, leading to a tolerable activation level.

  18. Risk assessment of 30 MeV cyclotron facilities

    International Nuclear Information System (INIS)

    Jeong, Gyo Seong; Lee, Jin Woo; Kim, Chong Yeal

    2017-01-01

    A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce 18F, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fres and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a free. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI

  19. Radial structure of curvature-driven instabilities in a hot-electron plasma

    International Nuclear Information System (INIS)

    Spong, D.A.; Berk, H.L.; Van Dam, J.W.

    1984-01-01

    A nonlocal analysis of curvature-driven instabilities for a hot-electron ring interacting with a warm background plasma has been made. Four different instability modes characteristic of hot-electron plasmas have been examined: the high-frequency hot-electron interchange (at frequencies larger than the ion-cyclotron frequency), the compressional Alfven instability, the interacting background pressure-driven interchange, and the conventional hot-electron interchange (at frequencies below the ion-cyclotron frequency). The decoupling condition between core and hot-electron plasmas has also been examined, and its influence on the background and hot-electron interchange stability boundaries has been studied. The assumed equilibrium plasma profiles and resulting radial mode structure differ somewhat from those used in previous local analytic estimates; however, when the analysis is calibrated to the appropriate effective radial wavelength of the nonlocal calculation, reasonable agreement is obtained. Comparison with recent experimental measurements indicates that certain of these modes may play a role in establishing operating boundaries for the ELMO Bumpy Torus-Scale (EBT-S) experiment. The calculations given here indicate the necessity of having core plasma outside the ring to prevent the destabilizing wave resonance of the precessional mode with a cold plasma

  20. Instability of warped discs

    Science.gov (United States)

    Doǧan, S.; Nixon, C. J.; King, A. R.; Pringle, J. E.

    2018-05-01

    Accretion discs are generally warped. If a warp in a disc is too large, the disc can `break' apart into two or more distinct planes, with only tenuous connections between them. Further, if an initially planar disc is subject to a strong differential precession, then it can be torn apart into discrete annuli that precess effectively independently. In previous investigations, torque-balance formulae have been used to predict where and when the disc breaks into distinct parts. In this work, focusing on discs with Keplerian rotation and where the shearing motions driving the radial communication of the warp are damped locally by turbulence (the `diffusive' regime), we investigate the stability of warped discs to determine the precise criterion for an isolated warped disc to break. We find and solve the dispersion relation, which, in general, yields three roots. We provide a comprehensive analysis of this viscous-warp instability and the emergent growth rates and their dependence on disc parameters. The physics of the instability can be understood as a combination of (1) a term that would generally encapsulate the classical Lightman-Eardley instability in planar discs (given by ∂(νΣ)/∂Σ < 0) but is here modified by the warp to include ∂(ν1|ψ|)/∂|ψ| < 0, and (2) a similar condition acting on the diffusion of the warp amplitude given in simplified form by ∂(ν2|ψ|)/∂|ψ| < 0. We discuss our findings in the context of discs with an imposed precession, and comment on the implications for different astrophysical systems.

  1. Study of first harmonic field effects on beam extraction for VEC K500 superconducting cyclotron

    International Nuclear Information System (INIS)

    Dey, M.K.; Debnath, J.; Mallik, C.; Bhandari, R.K.

    2002-01-01

    In superconducting cyclotron large momentum compaction at extraction region makes the turn separation very small. The first harmonic effects on the He +1 beam using simulated magnetic field for VEC K500 cyclotron is reported

  2. Reduction of the beam pulse repetition rate of the Hamburg Isochronous Cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Krause, H; Langkau, R; Schirm, N [Hamburg Univ. (F.R. Germany). 1. Inst. fuer Experimentalphysik

    1976-04-01

    A system for the reduction of the beam pulse repetition rate of the energy-variable Hamburg Isochronous Cyclotron comprising beam pulse supression in the cyclotron center and in the external beam is described.

  3. System Detects Vibrational Instabilities

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1990-01-01

    Sustained vibrations at two critical frequencies trigger diagnostic response or shutdown. Vibration-analyzing electronic system detects instabilities of combustion in rocket engine. Controls pulse-mode firing of engine and identifies vibrations above threshold amplitude at 5.9 and/or 12kHz. Adapted to other detection and/or control schemes involving simultaneous real-time detection of signals above or below preset amplitudes at two or more specified frequencies. Potential applications include rotating machinery and encoders and decoders in security systems.

  4. Evaporation and Antievaporation Instabilities

    Directory of Open Access Journals (Sweden)

    Andrea Addazi

    2017-10-01

    Full Text Available We review (antievaporation phenomena within the context of quantum gravity and extended theories of gravity. The (antievaporation effect is an instability of the black hole horizon discovered in many different scenarios: quantum dilaton-gravity, f ( R -gravity, f ( T -gravity, string-inspired black holes, and brane-world cosmology. Evaporating and antievaporating black holes seem to have completely different thermodynamical features compared to standard semiclassical black holes. The purpose of this review is to provide an introduction to conceptual and technical aspects of (antievaporation effects, while discussing problems that are still open.

  5. Superconducting cyclotron deflector conditioning status - an experience with high voltage

    International Nuclear Information System (INIS)

    Ghosh, Subhash; Chattopadhyay, Subrata; Bhattacharjee, Tanushyam; De, Anirban; Paul, Santanu; Pal, Gautam; Saha, Subimal; Mallik, C.; Bhandari, R.K.

    2009-01-01

    In this paper we report about the status of the electrostatic deflector which will be used in K500 superconducting cyclotron at VECC, Kolkata. For extraction of beams from superconducting cyclotron we have to achieve 130 kV/cm. Titanium and tungsten are used for anode and septum respectively. The deflector fits within the median plane of the superconducting magnet. We report here the voltage limit, sparking rates, dark current levels and the effects observed on conditioning. For commissioning of the superconducting cyclotron, the plan is to accelerate Neon beam of 50 MeV/n for which the required extraction voltage is 81 kV/cm and we reached up to 110 kV/cm. The conditioning test chamber is maintained at a pressure of 8.0 x 10 -7 mbar. (author)

  6. Radioisotope production by reactors and cyclotrons in Japan

    International Nuclear Information System (INIS)

    Murakami, Yukio

    1978-01-01

    Present status of radioisotope production in Japan and the increasing demand from various fields are generally reviewed. Future problems associated with the shortage of economical supply are also discussed. The first half of this report is devoted to general review of the increasing demand for various radioisotopes from increasing number of users. The present status and future trends of the distribution of users of specific radioisotopes and their demands are shown. The remaining half of this report reviews the production with reactors and cyclotrons. The Japanese reactors producing radioisotopes are limited to low flux (10 13 ) research reactors at JAERI. Some problems associated with the improvement of availability and with the organizational structure are discussed. As for the production with cyclotrons, available facilities and the method of production are explained in detail. For clinical use, especially for the production of short lived radioisotopes, the advantage of a small special purpose cyclotron at each medical organization is emphasized. (Aoki, K.)

  7. CACTUS - a multidetector set-up at the Oslo Cyclotron

    International Nuclear Information System (INIS)

    Guttormsen, M.; Bjerke, B.; Messelt, S.; Olsen, E.A.; Ramsoey, T.; Rekstad, J.; Tveter, T.S.; Wikne, J.C.; Kownacki, J.

    1989-06-01

    The design and construction of the multidetector system CACTUS is discussed, and its operation in the context of the Oslo Cyclotron is described. The multidetector system has been initiated to meet the requirements at the Oslo Cyclotron Laboratory in the experimental work on nuclear structure at high intrinsic excitation energy. The laboratory has developed a promising technique based on measuring γ-decay after single nucleon transfer reactions with the use of pγ coincidences. However, a proper interpretation of the experimental results has often been difficult due to low counting rates. One of the most important aims for the new experimental set-up has been to obtain pγ as well as pγγ coincidence spectra with high statistics. The CACTUS detector system which is mounted on the 90 o beam line of the cyclotron, consists of 28 NaI and 2 Ge detectors in combination with 8 Si particle telescopes

  8. 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...... of the electron cyclotron frequency. These are injected obliquely from the outside of the tokamak near an optimal angle to the magnetic field lines. This method involves two mode conversions. The ordinary waves are converted into extraordinary waves near the plasma cut-off layer. The extraordinary waves...... are subsequently converted into electrostatic electron Bernstein waves at the upper hybrid resonance layer, and the Bernstein waves are completely absorbed close to the plasma centre. Results are presented from ray-tracinq calculations in full three-dimensional geometry using the dispersion function for a hot non...

  9. Design study of the KIRAMS-430 superconducting cyclotron magnet

    International Nuclear Information System (INIS)

    Kim, Hyun Wook; Kang, Joonsun; Hong, Bong Hwan; Jung, In Su

    2016-01-01

    Design study of superconducting cyclotron magnet for the carbon therapy was performed at the Korea Institute of Radiological and Medical Science (KIRAMS). The name of this project is The Korea Heavy Ion Medical Accelerator (KHIMA) project and a fixed frequency cyclotron with four spiral sector magnet was one of the candidate for the accelerator type. Basic parameters of the cyclotron magnet and its characteristics were studied. The isochronous magnetic field which can guide the "1"2C"6"+ ions up to 430 MeV/u was designed and used for the single particle tracking simulation. The isochronous condition of magnetic field was achieved by optimization of sector gap and width along the radius. Operating range of superconducting coil current was calculated and changing of the magnetic field caused by mechanical deformations of yokes was considered. From the result of magnetic field design, structure of the magnet yoke was planned.

  10. Radiation monitoring in a self-shielded cyclotron installation

    International Nuclear Information System (INIS)

    Capaccioli, L.; Gori, C.; Mazzocchi, S.; Spano, G.

    2002-01-01

    As nuclear medicine is approaching a new era with the spectacular growth of PET diagnosis, the number of medical cyclotrons installed within the major hospitals is increasing accordingly. Therefore modern medical cyclotron are highly engineered and highly reliable apparatus, characterised with reduced accelerating energies (as the major goal is the production of fluorine 18) and often self-shielded. However specific dedicated monitors are still necessary in order to assure the proper radioprotection. At the Careggi University Hospital in Florence a Mini trace 10 MeV self-shielded cyclotron produced by General Electric has been installed in 2000. In a contiguous radiochemistry laboratory, the preparation and quality control of 1 8F DG and other radiopharmaceuticals takes place. Aim of this work is the characterisation and the proper calibration of the above mentioned monitors and control devices

  11. Isochronous variable energy cyclotron of IPEN-CNEN/SP (Brazil)

    International Nuclear Information System (INIS)

    Lucki, G.; Zanchetta, A.A.; Gouveia, S.; Klein, H.

    1984-01-01

    The cyclotron CV-28 installed at the Radiation Damage Division of IPEN-CNEN/SP is a multi-particle radiation source where protons, deuterons, 3 He ions and alpha particles can be accelerated with variable energy up to 24, 14, 36 and 28 MeV, respectively. The cyclotron is a versatile machine that can be applied in research and development of : radioisotope production - materials science - nuclear physics - activation analysis and others. First internal beam with 24 MeV protons has been obtained in April 23, 1981. First irradiation of Cu sample, at the external beam (beam current 1.5 μA), with 28 MeV alpha particles was performed in December 29, 1983. Main characteristics of the cyclotron are given together with a description of peripheral systems and experimental capability. Presently the accelerator is being optimized for cpontinuous running. (Author) [pt

  12. Design study of the KIRAMS-430 superconducting cyclotron magnet

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Wook; Kang, Joonsun, E-mail: genuinei@kirams.re.kr; Hong, Bong Hwan; Jung, In Su

    2016-07-01

    Design study of superconducting cyclotron magnet for the carbon therapy was performed at the Korea Institute of Radiological and Medical Science (KIRAMS). The name of this project is The Korea Heavy Ion Medical Accelerator (KHIMA) project and a fixed frequency cyclotron with four spiral sector magnet was one of the candidate for the accelerator type. Basic parameters of the cyclotron magnet and its characteristics were studied. The isochronous magnetic field which can guide the {sup 12}C{sup 6+} ions up to 430 MeV/u was designed and used for the single particle tracking simulation. The isochronous condition of magnetic field was achieved by optimization of sector gap and width along the radius. Operating range of superconducting coil current was calculated and changing of the magnetic field caused by mechanical deformations of yokes was considered. From the result of magnetic field design, structure of the magnet yoke was planned.

  13. Radiation effects testing at the 88-Inch Cyclotron at LBNL

    International Nuclear Information System (INIS)

    McMahan, Margaret A.; Koga, Rokotura

    2002-01-01

    The effects of ionizing particles on sensitive microelectronics is an important component of the design of systems as diverse as satellites and space probes, detectors for high energy physics experiments and even internet server farms. Understanding the effects of radiation on human cells is an equally important endeavor directed towards future manned missions in space and towards cancer therapy. At the 88-Inch Cyclotron at the Berkeley Laboratory, facilities are available for radiation effects testing (RET) with heavy ions and with protons. The techniques for doing these measurements and the advantages of using a cyclotron will be discussed, and the Cyclotron facilities will be compared with other facilities worldwide. RET of the same part at several facilities of varying beam energy can provide tests of the simple models used in this field and elucidate the relative importance of atomic and nuclear effects. The results and implications of such measurements will be discussed

  14. Automatized target devices for radioisotope production at the RITs cyclotron

    International Nuclear Information System (INIS)

    Bogdanov, P.V.; Ivanov, V.V.; Karasev, B.G.

    1981-01-01

    An automation target device intended for isotope production on the internal beam of the RITs cyclotron is decribed. The target device comprises the following main units: target head, vacuum lock, charging device, transport system for bringing the target for charging; mechanism of target discharge transport device, control interlocking and signalling control system of target radiation power. The automation target device permits radioisotope production on the cyclotron in commercial scales with automation substitution of irradiated targets. The time of substitution of one of six targets makes up only 5 min. The time of charging a new group of targets to the charge device - 60 min. Contact of the personnel with irradiated targets is practically excluded and the necessity of entering the cyclotron room for maintenance of the plant is reduced to the minimum [ru

  15. A 30 MeV H- cyclotron for isotope production

    International Nuclear Information System (INIS)

    Baartman, R.; Kleevan, W.J.; Laxdal, R.E.; Milton, B.F.; Otter, A.J.; Pearson, J.B.; Poirier, R.L.; Schmor, P.W.; Schneider, H.R.; Erdman, K.L.; Walker, Q.

    1989-01-01

    Because of an expanding market for radioisotopes there is a need for a new generation of cyclotrons designed specifically for this purpose. We describe such a cyclotron currently under construction. It is a 30 MeV H - design that exploits a newly developed high brightness multicusp ion source which is capable of H - currents of up to 5 mA. This together with careful beam matching then makes feasible accelerated H - beam intensities of 500 μA. The cyclotron being built is a four sector radial ridge design with two 45 degree dees in opposite valleys. Beam extraction is by stripping to H + in a thin graphite foil. Two extraction probes will allow simultaneous extraction of two beams, each with an intensity of up to 200 μA. Energy variation from 15 MeV to 30 MeV is achieved by varying the radial position of the extraction foil. 7 refs., 4 figs., 1 tab

  16. The Ion Cyclotron, Lower Hybrid, and Alfven Wave Heating Methods

    International Nuclear Information System (INIS)

    Koch, R.

    2004-01-01

    This lecture covers the practical features and experimental results of the three heating methods. The emphasis is on ion cyclotron heating. First, we briefly come back to the main non-collisional heating mechanisms and to the particular features of the quasilinear coefficient in the ion cyclotron range of frequencies (ICRF). The specific case of the ion-ion hybrid resonance is treated, as well as the polarisation issue and minority heating scheme. The various ICRF scenarios are reviewed. The experimental applications of ion cyclotron resonance heating (ICRH) systems are outlined. Then, the lower hybrid and Alfven wave heating and current drive experimental results are covered more briefly. Where applicable, the prospects for ITER are commented

  17. Nonlinear cyclotron-resonance accelerations by a generalized EM wave

    International Nuclear Information System (INIS)

    Akimoto, K.; Hojo, H.

    2004-01-01

    Particle accelerations by a one-dimensional, electromagnetic, dispersive pulse in an external magnetic field are investigated. It is found that the well-known cyclotron resonance may be classified into three regimes as the length and/or the amplitude of the pulse are varied. Namely, as the pulse amplitude increases, the transit-time cyclotron-resonance acceleration (CRA) evolves to phase trapping, and reflect particles. The amplitude and wave dispersion as well as the pulse length strongly affect those accelerations. The interesting phenomena of quantization of resonance velocities in between the two regimes are also investigated. This new mechanism may lead to wave amplification at some discrete frequencies other than the cyclotron frequency. (authors)

  18. Calibration of the simulation model of the VINCY cyclotron magnet

    Directory of Open Access Journals (Sweden)

    Ćirković Saša

    2002-01-01

    Full Text Available The MERMAID program will be used to isochronise the nominal magnetic field of the VINCY Cyclotron. This program simulates the response, i. e. calculates the magnetic field, of a previously defined model of a magnet. The accuracy of 3D field calculation depends on the density of the grid points in the simulation model grid. The size of the VINCY Cyclotron and the maximum number of grid points in the XY plane limited by MERMAID define the maximumobtainable accuracy of field calculations. Comparisons of the field simulated with maximum obtainable accuracy with the magnetic field measured in the first phase of the VINCY Cyclotron magnetic field measurements campaign has shown that the difference between these two fields is not as small as required. Further decrease of the difference between these fields is obtained by the simulation model calibration, i. e. by adjusting the current through the main coils in the simulation model.

  19. Stochasticity of the energy absorption in the electron cyclotron resonance

    International Nuclear Information System (INIS)

    Gutierrez T, C.; Hernandez A, O.

    1998-01-01

    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)

  20. CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

    International Nuclear Information System (INIS)

    Turner, S.

    1996-01-01

    These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being 'Cyclotrons, Linacs and Their Applications'. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.)

  1. CAS CERN Accelerator School: Cyclotrons, linacs and their applications. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Turner, S [ed.

    1996-03-04

    These proceedings present the lectures given at the eighth specialized course organized by the CERN Accelerator School (CAS), the topic this time being `Cyclotrons, Linacs and Their Applications`. Following an introductory lecture on linacs, the fundamental features of electron, ion and induction linacs are described together with their RF systems and particle sources. Cyclotrons are then introduced followed by details of their different types, their magnet and RF design, and their injection and extraction systems, with a glance towards exotic and possible future machines. Chapters are then presented on the use of linacs and cyclotrons for medical, fission, fusion and material applications, as well as for isotope production. Finally, descriptions of the design of a radioisotope facility, the matching of accelerators to their task and the computational tools used in their design are included. (orig.).

  2. The role of cold plasma and its composition on the growth of electromagnetic ion cyclotron waves in the inner magnetosphere

    Science.gov (United States)

    Snelling, J. M.; Johnson, J.; Engebretson, M. J.; Kim, E. H.; Tian, S.

    2017-12-01

    While it is currently well accepted that the free energy for growth of electromagnetic ion cyclotron (EMIC) waves in Earth's magnetosphere comes from unstable configurations of hot anisotropic ions that are injected into the ring current, several questions remain about what controls the instability. A recent study of the occurrence of EMIC waves relative to the plasmapause in Vallen Probes Data showed that plasma density gradients or enhancements were not the dominant factor in determining the site of EMIC wave generation [Tetrick et al. 2017]. However, the factors that control wave growth on each of the branches are not fully understood. For example, in some cases, the measured anisotropy is not adequate to explain local instability, and the relative importance of the density and composition of a cold plasma population is still uncertain. Several intervals of EMIC wave activity are analyzed to determine the role of a cold population in driving instability on each of the wave branches. This study utilizes the WHAMP (Waves in Homogeneous Anisotropic Magnetized Plasma) stability code with plasma distributions optimized to fit the observed distributions including temperature anisotropy, loss cone, and ring beam populations.

  3. Resonant Drag Instabilities in protoplanetary disks: the streaming instability and new, faster-growing instabilities

    Science.gov (United States)

    Squire, Jonathan; Hopkins, Philip F.

    2018-04-01

    We identify and study a number of new, rapidly growing instabilities of dust grains in protoplanetary disks, which may be important for planetesimal formation. The study is based on the recognition that dust-gas mixtures are generically unstable to a Resonant Drag Instability (RDI), whenever the gas, absent dust, supports undamped linear modes. We show that the "streaming instability" is an RDI associated with epicyclic oscillations; this provides simple interpretations for its mechanisms and accurate analytic expressions for its growth rates and fastest-growing wavelengths. We extend this analysis to more general dust streaming motions and other waves, including buoyancy and magnetohydrodynamic oscillations, finding various new instabilities. Most importantly, we identify the disk "settling instability," which occurs as dust settles vertically into the midplane of a rotating disk. For small grains, this instability grows many orders of magnitude faster than the standard streaming instability, with a growth rate that is independent of grain size. Growth timescales for realistic dust-to-gas ratios are comparable to the disk orbital period, and the characteristic wavelengths are more than an order of magnitude larger than the streaming instability (allowing the instability to concentrate larger masses). This suggests that in the process of settling, dust will band into rings then filaments or clumps, potentially seeding dust traps, high-metallicity regions that in turn seed the streaming instability, or even overdensities that coagulate or directly collapse to planetesimals.

  4. Band rejection filter for measurement of electron cyclotron emission during electron cyclotron heating

    International Nuclear Information System (INIS)

    Iwase, Makoto; Ohkubo, Kunizo; Kubo, Shin; Idei, Hiroshi.

    1996-05-01

    For the measurement of electron cyclotron emission from the high temperature plasma, a band rejection filter in the range of 40-60 GHz is designed to reject the 53.2 GHz signal with large amplitude from the gyrotron for the purpose of plasma electron heating. The filter developed with ten sets of three quarters-wavelength coupled by TE 111 mode of tunable resonant cavity has rejection of 50 dB and 3 dB bandwidth of 500 MHz. The modified model of Tschebysheff type for the prediction of rejection is proposed. It is confirmed that the measured rejection as a function of frequency agrees well with the experimental results for small coupling hole, and also clarified that the rejection ratio increases for the large coupling hole. (author)

  5. Electron cyclotron resonance plasmas and electron cyclotron resonance ion sources: Physics and technology (invited)

    International Nuclear Information System (INIS)

    Girard, A.; Hitz, D.; Melin, G.; Serebrennikov, K.

    2004-01-01

    Electron cyclotron resonance (ECR) ion sources are scientific instruments particularly useful for physics: they are extensively used in atomic, nuclear, and high energy physics, for the production of multicharged beams. Moreover, these sources are also of fundamental interest for plasma physics, because of the very particular properties of the ECR plasma. This article describes the state of the art on the physics of the ECR plasma related to multiply charged ion sources. In Sec. I, we describe the general aspects of ECR ion sources. Physics related to the electrons is presented in Sec. II: we discuss there the problems of heating and confinement. In Sec. III, the problem of ion production and confinement is presented. A numerical code is presented, and some particular and important effects, specific to ECR ion sources, are shown in Sec. IV. Eventually, in Sec. V, technological aspects of ECR are presented and different types of sources are shown

  6. Next customers to cyclotron center meanwhile are not entered

    International Nuclear Information System (INIS)

    Bato, R.; Zackova, K.

    2004-01-01

    In this paper the financial aspects of construction of the Cyclotron Centre of the Slovak Republic (CC SR) are analysed. This building represents the problems of exploitation of commodity deblocation of Russian Federation debt to Slovakia. The estimated expenses have risen from original planned 2 billion Slovak crowns to 6 billion Slovak crowns. Devices which should be part of centre - a cyclotron used for radiopharmaceuticals production for oncological purposes and a big cyclotron for industrial purposes, a centre of positron emissive tomography (PET), a laboratory of nano-technologies, a source of heavy ions - they indicates that the oncological institutes, departments of health service, of education, of economy, of defence, of environment, also Nuclear Regulatory Authority of Slovak Republic and Slovak Academy of Sciences should become the customers principally. Around 2.2 billion of Slovak crowns from deblocation have been spent for a construction of Cyclotron Centre of SR yet. The national budget has contributed by 95 million Slovak crowns; 90.5 million USD will be obtained from deblocation of Russian debt yet. IAEA has supported this centre by grant of almost 800 thousand USD. Budget of Cyclotron Centre of SR is still rising also because of rising of VAT from 10 percent to 19 percent. VAT will be paid also for goods imported within the framework of deblocation after integration of Slovak Republic to European Union; besides also 10 percent duty is paid. Project of CC SR has not passed the state expert opinion. Agreement for construction of Cyclotron Centre of SR was issued by State Health Institute of Bratislava, therefore it was confirmed also by the main hygienist of Slovak Republic

  7. Calculations for the design and modification of the 2 cyclotrons of S.A.R.A

    International Nuclear Information System (INIS)

    Albrand, P.S.; Belmont, J.L.; Ripouteau, F.

    1983-09-01

    S.A.R.A. is a heavy ion accelerator constituted by 2 cyclotrons. The second cyclotron (post-accelerator) was entirely calculated at the I.S.N. The pole tips of the first cyclotron which is much older, have recently been modified. An almost identical procedure was used for the calculation of each element of the post-accelerator of S.A.R.A. and also for the modifications to the first cyclotron

  8. Feedback stabilization of plasma instabilities

    International Nuclear Information System (INIS)

    Cap, F.F.

    1977-01-01

    This paper reviews the theoretical and experimental aspects of feedback stabilization. After giving an outline of a general theoretical model for electrostatic instabilities the author provides a theoretical analysis of the suppression of various types of instability. Experiments which have been carried out on the feedback stabilization of various types of plasma instability are reported. An extensive list of references is given. (B.R.H.)

  9. Thermal Shrinkage for Shoulder Instability

    OpenAIRE

    Toth, Alison P.; Warren, Russell F.; Petrigliano, Frank A.; Doward, David A.; Cordasco, Frank A.; Altchek, David W.; O’Brien, Stephen J.

    2010-01-01

    Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent...

  10. Political Instability and Economic Growth

    OpenAIRE

    Alberto Alesina; Sule Ozler; Nouriel Roubini; Phillip Swagel

    1992-01-01

    This paper investigates the relationship between political instability and per capita GDP growth in a sample of 113 countries for the period 1950-1982. We define ?political instability? as the propensity of a government collapse, and we estimate a model in which political instability and economic growth are jointly determined. The main result of this paper is that in countries and time periods with a high propensity of government collapse, growth is significantly lower than otherwise. This ef...

  11. E × B electron drift instability in Hall thrusters: Particle-in-cell simulations vs. theory

    Science.gov (United States)

    Boeuf, J. P.; Garrigues, L.

    2018-06-01

    The E × B Electron Drift Instability (E × B EDI), also called Electron Cyclotron Drift Instability, has been observed in recent particle simulations of Hall thrusters and is a possible candidate to explain anomalous electron transport across the magnetic field in these devices. This instability is characterized by the development of an azimuthal wave with wavelength in the mm range and velocity on the order of the ion acoustic velocity, which enhances electron transport across the magnetic field. In this paper, we study the development and convection of the E × B EDI in the acceleration and near plume regions of a Hall thruster using a simplified 2D axial-azimuthal Particle-In-Cell simulation. The simulation is collisionless and the ionization profile is not-self-consistent but rather is given as an input parameter of the model. The aim is to study the development and properties of the instability for different values of the ionization rate (i.e., of the total ion production rate or current) and to compare the results with the theory. An important result is that the wavelength of the simulated azimuthal wave scales as the electron Debye length and that its frequency is on the order of the ion plasma frequency. This is consistent with the theory predicting destruction of electron cyclotron resonance of the E × B EDI in the non-linear regime resulting in the transition to an ion acoustic instability. The simulations also show that for plasma densities smaller than under nominal conditions of Hall thrusters the field fluctuations induced by the E × B EDI are no longer sufficient to significantly enhance electron transport across the magnetic field, and transit time instabilities develop in the axial direction. The conditions and results of the simulations are described in detail in this paper and they can serve as benchmarks for comparisons between different simulation codes. Such benchmarks would be very useful to study the role of numerical noise (numerical

  12. Solid targets for production of radioisotopes with cyclotron

    International Nuclear Information System (INIS)

    Paredes G, L.; Balcazar G, M.

    1999-01-01

    The design of targets for production of radioisotopes and radiopharmaceuticals of cyclotron to medical applications requires a detailed analysis of several variables such as: cyclotron operation conditions, choice of used materials as target and their physicochemical characteristics, activity calculation, the yielding of each radioisotope by irradiation, the competition of nuclear reactions in function of the projectiles energy and the collision processes amongst others. The objective of this work is to determine the equations for the calculation for yielding of solid targets at the end of the proton irradiation. (Author)

  13. The Juelich compact cyclotron - a multi-purpose irradiation facility

    International Nuclear Information System (INIS)

    Hemmerich, J.; Hoelzle, R.; Kogler, W.

    1977-01-01

    A commercially available variable-energy compact cyclotron has been installed at the Kernforschungsanlage Juelich. It is equipped to accelerate protons, deuterons, 3 He- and α-particles. A +- 60 0 switching magnet allows to switch the beam to any of seven external target stations. Three separately shielded target rooms allow a flexible use of the cyclotron for a wide range of applications such as production of short-lived nuclides, activation analysis, radiation damage studies in metals and studies of biological effects of fast neutron irradiation. (orig.) [de

  14. Superconducting conversion of the Oak Ridge Isochronous Cyclotron

    International Nuclear Information System (INIS)

    Martin, J.A.; Ball, J.B.; Cleary, E.D.

    1981-01-01

    The superconducting conversion of the Oak Ridge Isochronous Cyclotron (ORIC) will replace the existing aluminum main magnet coils with a NbTi superconducting coil system to provide an increase in magnetic field from 1.9 to 3.3 T. The higher magnetic field will provide a three-fold increase in maximum energy capability of the cyclotron for high mass ions. The conversion will include a new beam extraction system, magnet yoke stiffening to counteract the increased magnetic forces, and minor modifications to the beam transport systems and shielding

  15. The National Medical Cyclotron - An Australian experience in technology

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, R K [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). National Medical Cyclotron

    1998-12-31

    The establishment of the National Medical Cyclotron (NMC) in the early 1990`s was the practical outcome of a vision, held by nuclear medicine professionals, to complement the available neutron-rich radionuclides produced in Australia, with neutron-deficient radionuclides. The NMC is operated by the Australian Nuclear Science and Technology Organisation (ANSTO) in collaboration with the Royal Prince Alfred Hospital (RPAH) in Sydney where the PET department is able to use the short-lived radiotracers to good advantage. Neutron-deficient radionuclides, are also produced by the NMC laboratories. The cyclotron-generated radionuclides are used in over 70,000 patient studies per year. 7 refs., 1 tab.

  16. A 600 MeV cyclotron for radioactive beam production

    International Nuclear Information System (INIS)

    Clark, D.J.

    1993-01-01

    The magnetic field design for a 600 MeV proton cyclotron is described. The cyclotron has a single stage, a normal conducting magnet coil and a 9.8 m outside yoke diameter. It has 8 sectors, with a transition to 4 sectors in the center region. The magnetic field design was done using 1958 Harwell rectangular ridge system measurements and was compared with recent 3-dimensional field calculations with the program TOSCA at NSCL. The center region 4--8 sector transition focussing was also checked with TOSCA

  17. A compact cost-effective beamline for a PET Cyclotron

    International Nuclear Information System (INIS)

    Dehnel, M.P.; Jackle, P.; Roeder, M.; Stewart, T.; Theroux, J.; Brasile, J.P.; Sirot, P.; Buckley, K.R.; Bedue, M.

    2007-01-01

    Most commercial PET Cyclotrons have targets mounted on or near the main cyclotron vacuum chamber. There is often little or no system capability for centering or focusing the extracted beam on target to achieve maximum production. This paper describes the ion-optics, design and development of a compact cost-effective beamline comprised of low activation and radiation resistant materials. The beamline, complete with suitable diagnostic devices, permits the extracted proton beam to be centered (X-Y steering magnet), and focused (quadrupole doublet) on target eliminating unnecessary beamspill and ensuring high production

  18. The National Medical Cyclotron - An Australian experience in technology

    International Nuclear Information System (INIS)

    Barnes, R. K.

    1997-01-01

    The establishment of the National Medical Cyclotron (NMC) in the early 1990's was the practical outcome of a vision, held by nuclear medicine professionals, to complement the available neutron-rich radionuclides produced in Australia, with neutron-deficient radionuclides. The NMC is operated by the Australian Nuclear Science and Technology Organisation (ANSTO) in collaboration with the Royal Prince Alfred Hospital (RPAH) in Sydney where the PET department is able to use the short-lived radiotracers to good advantage. Neutron-deficient radionuclides, are also produced by the NMC laboratories. The cyclotron-generated radionuclides are used in over 70,000 patient studies per year

  19. New type sector cyclotron and improvement of EULIMA project

    International Nuclear Information System (INIS)

    Gao, Shuyang

    1988-01-01

    In this paper the two sorts of new type sector cyclotron have been discussed. Both of them remain with the same structure as straight-side sector magnet; but the annular shim systems are added on the pole faces of the every sectors. One of them has one group of the shim system; another has the three groups on the every sector. The analytical expressions of the magnetic field for the structure have been given. The linear motion stability of the particles has been proved. The new type of the compact superconducting cyclotron in the median energy is put forward as an instance for its application to the EULIMA project. (author)

  20. Polarized electron cyclotron emission in the Tokapole II Tokamak

    International Nuclear Information System (INIS)

    Sengstacke, M.A.; Dexter, R.N.; Prager, S.C.

    1984-06-01

    To examine the effect of wall reflections we have measured the polarization of second harmonic cyclotron emission (at omega = 2 omega/sub ce/) in the Tokapole II tokamak both with and without a microwave absorber installed within the field of view of the receiving antenna. Indeed, the local elimination of wall reflections markedly enhances the polarization, as described in section II. Section III describes observations consistent with right-hand cutoff effects and an attempt to infer the electron temperature from cyclotron emission in an optically thin plasma