Particle Acceleration At Comet Related Shock Surfaces

  • Susan M. P. Mckenna-Lawlor
  • E. Kirsch
  • P. Daly
Conference paper

Abstract

A standard picture of how comets interact with the Solar Wind has been developed over approximately the last decade through theoretical analysis, backed by in situ measurements made from spacecraft at comets. According to this scenario, see for example Galeev (1986), Galeev and Sagdeev (1988), Johnstone et al. (1991) and Coates et al. (1989, 1990, 1993a), neutral atoms exiting from a comet nucleus become ionised through a number of processes. In the spacecraft frame, a newly formed ion is created essentially at rest and then undergoes cycloidal motion in the crossed magnetic and electric fields of the Solar Wind. If the angle between the interplanetary magnetic field and the Solar Wind is a, the ions drift at a speed vsw sinα in the E x B direction and display a maximum energy (Emax) on the cycloidal trajectory given by Emax=4Asin2α Esw (where A is the ion mass in a.m.u. and Esw is the kinetic energy of a proton travelling with the Solar Wind velocity). Thus, the peak energy depends on the magnetic field direction (which typically changes on time scales of a few minutes) and on the Solar Wind velocity (which typically varies on a time scale of a few hours). In the Solar Wind rest frame, ions are created with a speed equal to the Solar Wind speed in the comet’s rest frame and form a ring in velocity space as they gyrate about the magnetic field lines. This pickup ring distribution is unstable to the generation of waves, leading to pitch angle scattering around a bispherical shell. If efficient pitch angle scattering occurs in the flow rest frame the peak energy of the ions is 4A Esw, irrespective of the field direction, and the mean direction of motion depends only on the direction of the Solar Wind flow.

Keywords

Energetic Particle Solar Wind Velocity Alfven Wave Shock Surface Diffusive Shock Acceleration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References

  1. Amata, E. and Formisano, V: 1985, ‘Energization of positive ions in the cometary foreshock region’. Planet. Space Sci., 33, 1243.ADSCrossRefGoogle Scholar
  2. Armstrong, T.P., Pesses, M.E., and Decker, R.D: 1987, ‘Shock drift acceleration in Collisionless shocks in the Heliosphere: Reviews of current research’. Geophys. Monograph Series Vol. 35, 271, ed. B.T. Tsurutani and R.G. Stone, American Geophysical Union, Washington D.C.Google Scholar
  3. Coates, A.J., Johnstone, A.D., Wilken, B., Jockers, K. and Glassmeier, K-H: 1989, ‘Velocity space diffusion of pickup ions from the water group at comet Halley’. J. Geophys. Res. 94, 9983.ADSCrossRefGoogle Scholar
  4. Coates, A.J., Johnstone, A.D., Wilken, B., Jockers, K. and Glassmeier, K-H: 1990, ‘Correction to Coates et al. 1989’. J. Geophys. Res. 95, 4343.ADSCrossRefGoogle Scholar
  5. Coates, A.J., Johnstone, A.D., Wilken, B. and Neubauer, F.M: 1993a, ‘Velocity space diffusion and nongyrotropy of pickup water group ions at comet Grigg-Skjellerup’. J. Geophys. Res. 98, 20985.ADSCrossRefGoogle Scholar
  6. Coates, A.J., Johnstone, A.D., Huddieston, D.E., Wilken, B., Jockers, K. Borg, H., Amata, E., Formisano, V., Bavassano-Cattaneo, M.B., Winningham, J.D., Gurgiolo and Neubauer, F.M: 1993b, ‘Pickup water group ions at comet Grigg-Skjellerup’. Geophys. Res. Lett., 20. 483.ADSCrossRefGoogle Scholar
  7. Decker, R.B. and Vlahos, L: 1986, ‘Modeling of ion acceleration through drift and diffusion at interplanetary shocks’ J. Geophys. Res. 91, 13349.ADSCrossRefGoogle Scholar
  8. Fisk, L.A: 1976, ‘The acceleration of energetic particles in the interplanetary medium by transit time damping’. J. Geophys. Res., 81, 4633.ADSCrossRefGoogle Scholar
  9. Galeev, A.A: 1986, ‘Theory and observations of solar wind/cometary plasma interaction processes’. Proc. 20th. ESLAB Symposium on the Exploration of Halley’s Comet, ESA SP-250, Vol. 1, 3, eds. B. Battrick, E. J. Rolfe and R. Reinhard.Google Scholar
  10. Galeev, A.A. and Sagdeev, R.Z: 1988, ‘Alfven waves in a space plasma and its role in the solar wind interaction with comets’. Astrophys. Space Sci. 144, 427.ADSGoogle Scholar
  11. Glassmeier, K.-H., Neubauer, F.M., Acuna, M.H. and Mariani, F: 1987, ‘Low frequency magnetic field fluctuations in comet P/Halley’s magnetosheath, Giotto observations’. Astron. Astrophys. 187, 65.ADSGoogle Scholar
  12. Glassmeier, K.-H. and Neubauer, F.M: 1993, ‘Low frequency electromagnetic plasma waves at comet P/Grigg-Skjellerup: overview and spectral characteristics,’. J. Geophys. Res. 98, 20921.ADSCrossRefGoogle Scholar
  13. Gombosi, T.I., Lorencz, K. and Jokipii, J.R: 1989, ‘Combined first and second order Fermi acceleration at comets’. Adv. Space Res., 9, 3337.Google Scholar
  14. Hynds, R.J., Cowley, S.W.H., Sanderson, T.R., Wenzel, K.-P. and van Rooijen, J.J: 1986, ‘Observations of energetic ions from comet Giacobini-Zinner’. Science 232, 361.ADSCrossRefGoogle Scholar
  15. Ip, H.W. and Axford, W.I: 1986, ‘The acceleration of particles in the vicinity of comets’. Planet. Space Sci;, 34, 1061.ADSCrossRefGoogle Scholar
  16. Ip, H.W. and Axford, W.I: 1987, ‘A numerical simulation of charged particle acceleration and pitch-angle scattering in the turbulent plasma environment of comets’. Proc. 20th. Internat. Cosmic ray Conf. Moscow, Vol. 3, pp. 233, International Union of Pure and Applied Physics, Moscow.Google Scholar
  17. Ipavich, F.M: 1974, ‘The Compton Getting effect for low energy particles’. Geophys. Res. Lett. 1, 149.ADSCrossRefGoogle Scholar
  18. Johnstone, A., Coates, A., Kellock, S., Wilken, B., Jockers, K., Rosenbauer, R., Studemann, W., Weiss, W., Formisano, V., Amata, E., Cerulli-Irelli, R., Dobrowolny, M., Terenzi, R., Egidi, A., Borg, H., Hultquist, B., Winningham, J., Gurgiolo, C., Bryant, D., Edwards, T., Feldman, W., Thomsen, M., Wallis, M.K., Biermann, L., Schmidt, H., Lust, R., Haerendel, G. and Paschmann, G: 1986, ‘Ion flow at comet Halley’. Nature, 321(6067) 344.ADSCrossRefGoogle Scholar
  19. Johnstone, A.D., Huddleston, D.E. and Coates, A.J: 1991, ‘The spectrum and energy density of solar wind turbulence of cometary origin in Cometary Plasma Processes’. Geophys. Monogr. Ser. Vol. 61, 259, ed. A.D. Johnstone, AGU, Washington D.C.Google Scholar
  20. Johnstone, A.D., Coates, A.J., Huddleston, D.E., Jockers, K., Wilken, B., Borg, H., Gurgiolo, C., Winningham, J.DS. and Amata, E: 1993, ‘Observations of the solar wind and cometary ions during the encounter between Giotto and comet P/Grigg-Skjellerup’. Astron. Astrophys. 273, L1.ADSGoogle Scholar
  21. Kecskemety, K., Cravens, T.E., Afonin, V.V., Erdos, G., Eroshenko, E.G., Gan, Lu., Gombosi, T.I., Gringauz, K.I., Keppler, E., Klimenko, I.N., Marsden, R., Nagy, A.F., Remizov, A.P., Richter, A.K., Riedler, W., Schwingenschuh, K., Somogyi, A.J., Szego, K., Tatrallyay, M., Vaga, A., Verigin, M.I. and Wenzel, K-P: 1989, ‘Pickup ions in the unshocked solar wind at comet Halley’. J. Geophys. Res. 94, 185.ADSCrossRefGoogle Scholar
  22. Kecskemety, K. and Cravens, T.E: 1992a, ‘Accelerated cometary ions observed downstream of the comet Halley Bow Shock’. J. Geophys. Res. 97, No. A3, 2891.ADSCrossRefGoogle Scholar
  23. Kecskemety, K. and Cravens, T.E: 1992b, ‘Correction to Accelerated cometary ions observed downstream of the comet Halley Bow Shock’. J. Geophys. Res. 97, No. A6, 8719.ADSCrossRefGoogle Scholar
  24. Kirsch, E., McKenna-Lawlor, S., Daly, P., Korth, A. Neubauer, F.M., O’Sullivan, D., Thompson, A. and Wenzel, K.-P: 1989, ‘Evidence for the field line reconnection process in the particle and magnetic field measurements obtained during the Giotto-Halley encounter’. Ann. Geophys. 7, (2) 107.ADSGoogle Scholar
  25. Kirsch, E., McKenna-Lawlor, S., Daly, P., Korth, A. Neubauer, F.M., O’Sullivan, D., Thompson, A. and Wenzel, K.-P: 1990, ‘Particle observations by EPA/EPONA during the outbound pass of Giotto from comet Halley and their relationship to large-scale magnetic field irregularities’. Ann. Geophys. 9, 455.ADSGoogle Scholar
  26. Kirsch, E., McKenna-Lawlor, S., Daly, P.W., Neubauer, F.M., Coates, A., Thompson, A., O’Sullivan, D. and Wenzel, K-P: 1991, ‘Energetic water group ions fluxes (EH20 > 60 keV) in a quasiperpendicular and a quasiparallel shock front as observed during the Giotto-Halley encounter’. In Cometary Plasma Processes, Geophys. Monogr. Series, Vol. 61, 357, American Geophys. Union, Washington D.C.CrossRefGoogle Scholar
  27. Krankowsky, D., Lammerzahl, P., Herrewerth, L, Woweries, J., Eberhardt, P., Dolder, U., Hermann, U., Schulte, W., Berthelier, J.J., Illiano, J.M., Hodges, R.R. and Hoffman, J.H: 1986, ‘In situ gas and ion measurements at comet Halley’. Nature, 321(6067), 326.ADSCrossRefGoogle Scholar
  28. McKenna-Lawlor, S., Kirsch, E., O’Sullivan, D., Thompson, A. and Wenzel, K-P: 1986, ‘Energetic ions in the environment of comet Halley’. Nature 321, (6067), 347.ADSCrossRefGoogle Scholar
  29. McKenna-Lawlor, S., Kirsch, E., Thompson, A., O’Sullivan D. and Wenzel, K-P: 1987, ‘The lightweight energetic particle detector EPONA and its performance on Giotto’. J. Phys. E.: Sci. Instrum. 20, 732.ADSCrossRefGoogle Scholar
  30. McKenna-Lawlor, S.M.P., Daly, P.W., Kirsch, E., O’Sullivan, D., Thompson, A., Wenzel, P.-K. and Afonin, V: 1993, ‘Energetic ions at comet Grigg-Skjellerup measured from the Giotto spacecraft’. Nature, 363, 326.ADSCrossRefGoogle Scholar
  31. McKenna-Lawlor, Susan, Afonin, V.V., Kirsch E. and Daly, P: 1997, ‘Characteristic boundary transitions in energetic particle data (60-≥ 260 keV) recorded at comets P/Grigg-Skjellerup and P/Halley by the EPONA instrument on Giotto’. Planet. Space Sci 45 No. 9, 1119.ADSCrossRefGoogle Scholar
  32. Mazelle, C., Reme, H., Neubauer, F.M. and Glassmeier, K-H: 1995, ‘Comparison of the main magnetic and plasma features in the environments of comets Grigg-Skjellerup and Halley’. Adv. Space Res. 16, 441.CrossRefGoogle Scholar
  33. Neubauer, F.M., Glassmeier, K-H., Pohl, M., Raeder, J., Acuna, M.H., Burlaga, I.F., Ness, N.F., Musmann, G., Mariani, F., Wallis, M.K., Ungstrup, E. and Schmidt, H.U: 1986, ‘First results from the Giotto magnetometer experiment at comet Halley’. Nature 321, (6067), 352.ADSCrossRefGoogle Scholar
  34. Neubauer, F.M., Glassmeier, K-H., Acuna, M.H., Mariani, F., Musmann, G., Ness, N.F. and Coates, A.J: 1990, ‘Giotto magnetic field observations at the outbound bow shock of comet Halley’. Ann. Geophys. 8 (7-8), 463.ADSGoogle Scholar
  35. Neubauer, F.M., Marschall, H., Pohl, M., Glassmeier, K-H., Musmann, G., Mariani, F., Acuna, M.H., Burlaga, L.F., Ness, N.F., Wallis, M.K., Schmidt, H.U. and Ungstrup, E: 1993a, ‘First results from the Giotto Magnetometer experiment during the P/Grigg-Skjellerup encounter’. Astron. Astrophys. 268, L5.ADSGoogle Scholar
  36. Neubauer, F.M., Glassmeier, K-H., Coates, A.J. and Johnstone, A.D: 1993b, ‘Low-frequency electromagnetic plasma waves at comet P/Grigg-Skjellerup: analysis and interpretation’. J. Geophys. Res. 98, 20,937.Google Scholar
  37. Richardson, J.G., Cowley, S.W. H., Hynds, R.J., Tranquille, C., Sanderson, T.R., Wenzel, K-P and Daly, P. W: 1987, ‘Observations of energetic water group ions at comet Giacobini-Zinner: implications for ion acceleration processes’. Planet. Space Sci. 35, 1323.ADSCrossRefGoogle Scholar
  38. Somogyi, A.J., Axford, W.I., Erdos, G., Ip, W-H, Shapiro, V.D. and Shevechenko: 1990, ‘Particle acceleration in the plasma fields near Comet Halley’. In Comet Halley, Investigations, Results, Interpretations, Vol. 1, Organisation, Plasma, Gas, ed. J. Mason, Chap. 13, 202, Ellis Horwood.ADSGoogle Scholar
  39. Tsurutani, B.T., Brinca, A.L., Smith, E.J., Thome, R.M., Scarf, F.L., Gosling, J.T. and Ipavich, F.M: 1986, ‘MHD waves detected by ICE at distances > 28 x 106 km from Comet Halley: Cometary or Solar Wind origin?’ Proc. 20th. ESLAB Symposium on the Exploration of Halley’s Comet, ESA SP-250, Vol. 3, 451, eds. B. Battrick, E. J. Rolfe and R. Reinhard.Google Scholar
  40. Wenzel, K-P., Sanderson, T.R., Richardson, I.G., Cowley, S.W.H., Hynds, R.J., Bame, S.J., Zwickl, R.D., Smith, E.J., and Tsurutani, B.T: 1986, ‘In-situ observations of cometary pick-up ions ≥ 0.2 AU upstream of comet Halley: ICE observations’. Geophys. Res. Lett. 13, 861.ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • Susan M. P. Mckenna-Lawlor
    • 1
  • E. Kirsch
    • 2
  • P. Daly
    • 2
  1. 1.Maynooth, Co.Space Technology Ireland, LtdKildareIreland
  2. 2.Max Planck Institut fur AeronomieKatlenburg-LindauGermany

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