Observation of fast-ion Doppler-shifted cyclotron resonance with shear Alfvén waves

Yang Zhang; Heidbrink, W. W.; Boehmer, H.; McWilliams, R.; Vincena, S.; Carter, T. A.; Gekelman, W.; Leneman, D.; Pribyl, P.
October 2008
Physics of Plasmas;Oct2008, Vol. 15 Issue 10, p102112
Academic Journal
The Doppler-shifted cyclotron resonance (ω-kzvz=Ωf) between fast ions and shear Alfvén waves is experimentally investigated (ω, wave frequency; kz, axial wavenumber; vz, fast-ion axial speed; Ωf, fast-ion cyclotron frequency). A test particle beam of fast ions is launched by a Li+ source in the helium plasma of the LArge Plasma Device (LAPD) [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Instrum. 62, 2875 (1991)], with shear Alfvén waves (SAW) (amplitude δ B/B up to 1%) launched by a loop antenna. A collimated fast-ion energy analyzer measures the nonclassical spreading of the beam, which is proportional to the resonance with the wave. A resonance spectrum is observed by launching SAWs at 0.3–0.8ωci. Both the magnitude and frequency dependence of the beam-spreading are in agreement with the theoretical prediction using a Monte Carlo Lorentz code that launches fast ions with an initial spread in real/velocity space and random phases relative to the wave. Measured wave magnetic field data are used in the simulation.


Related Articles

  • Formation of field-reversed ion rings in a magnetized background plasma. Omelchenko, Yu. A.; Sudan, R.N. // Physics of Plasmas;Jul95, Vol. 2 Issue 7, p2773 

    Studies the beam evolution in a preformed background plasma on a time scale greater than an ion cyclotron period. Occurrence of axial beam bunching in the downstream applied field; Formation of a compact field-reversed ring; Reflection of the ring in a ramped magnetic field.

  • Collective acceleration of laser-produced ions. Cremer, J. T.; Destler, W. W. // Journal of Applied Physics;5/1/1985, Vol. 57 Issue 9, p4391 

    Presents studies of the collective acceleration of ions from a laser-produced plasma located immediately downstream of the anode. Experimental configuration used for such studies; Typical ion time of flight signals; Results of Thomson spectrometer measurements of accelerated ion charge states...

  • Temperature of ion cyclotron heated impurity ions in fusion plasmas. Pilipenko, D.; Tokar, M. Z.; Pavlenko, I.; Weyssow, B. // Physics of Plasmas;Jul2005, Vol. 12 Issue 7, p072521 

    The temperature of impurity ions in fusion plasmas is normally assumed to be the same as that of background particles. This assumption can be, however, violated for selective impurity species intensively heated by radio frequency waves or in reactor plasmas of low collisionality. An approach to...

  • High current carbon beam production with direct plasma injection scheme. Okamura, Masahiro; Kashiwagi, Hirotsugu; Sakakibara, Kazuhiko; Takano, Jumpei; Hattori, Toshiyuki; Hayashizaki, Noriyosu; Jameson, Robert A.; Yamamoto, Kazuo // Review of Scientific Instruments;Mar2006, Vol. 77 Issue 3, p03B303 

    We have been studying a new heavy-ion production technique called “direct plasma injection scheme,” DPIS, since 2000. A new radio frequency quadrupole (RFQ) designed especially for the DPIS was commissioned in 2004 and very intense carbon beam was successfully obtained, reaching more...

  • Guiding center atoms: Three-body recombination in a strongly magnetized plasma. Glinsky, Michael E.; O’Neil, Thomas M. // Physics of Fluids B: Plasma Physics;May91, Vol. 3 Issue 5, p1279 

    The three-body recombination rate is calculated for an ion introduced into a magnetically confined, weakly correlated, and cryogenic pure electron plasma. The plasma is strongly magnetized in the sense that the cyclotron radius for an electron rce=(kBTe/me)1/2/Ωce is small compared to the...

  • Plasma potential enhancement by rf heating near the ion-cyclotron frequency. Smith, D. K.; Brau, K.; Goodrich, P.; Irby, J.; Mauel, M. E.; McVey, B. D.; Post, R. S.; Sevillano, E.; Sullivan, J. // Physics of Fluids (00319171);Apr86, Vol. 29 Issue 4, p902 

    The observation of enhanced plasma potentials, i.e., potentials greater than the Boltzmann values, in a mirror device is reported. The potential structure is driven by strong radio frequency heating near the ion-cyclotron resonance and near the local electron bounce frequency. The potentials and...

  • Numerical studies of minority ion heating current drive. Wong, K. L.; Ishihara, O.; Gahl, J.; Hagler, M.; Kristiansen, M. // Physics of Fluids (00319171);Mar87, Vol. 30 Issue 3, p834 

    Current generation by asymmetrical heating of minority ions without the injection of net momentum into a plasma is studied numerically by solving the Fokker-Planck equation in which the quasilinear diffusion term for cyclotron absorption is added to the Coulomb collision terms. The results show...

  • Excitation and detection of ICR modes for control and analysis of a multicomponent plasma. Schweikhard, L.; Ziegler, J.; Beiersdorfer, P.; Beck, B.; Becker, St; Elliott, S. // Review of Scientific Instruments;Jan1995, Vol. 66 Issue 1, p448 

    Develops methods to analyze and control the ionic composition of a confined plasma with use of ion cyclotron modes. Resolution of powers much higher than possible with time-of-flight analysis.

  • Review of Beam Driven Plasma Wakefield Accelerators. Joshi, C. // AIP Conference Proceedings;2004, Vol. 737 Issue 1, p3 

    The current status of the beam-driven plasma wakefield accelerators is reviewed. © 2004 American Institute of Physics


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics