%V 24 %D 1997 %T Pick-up ions and associated wave energy transport at Comet P/Halley: A case study %K Solar-wind, Elsasser variables, Halley, Turbulence %N 3 %P 305 - 308 %X During the flyby of the spacecraft Giotto at comet p/Halley Poynting vectors and Elsässer variables have been determined to study wave propagation directions. The observed wave properties are compared with the theoretically predicted RH −, LH + and LH − wave modes. Between 10:36 and 19:11 SCET on March 13, 1986 the predicted dominating energy propagation direction mostly corresponds with the observed one. Only between 12:11 and 13:44 SCET there is no agreement. In this region the excitation of waves is dominated by pickâ€up ions which are not locally implanted ions in the solar wind but have been pickedâ€up outside the plasma regime studied, and whose free energy is not already used up. %A A Söding %A K-H Glassmeier %A A Johnstone %A FM Neubauer %A AJ Coates %J Geophysical Research Letters %O Copyright 1997 by the American Geophysical Society %L discovery398860