Direct Measurement of Desorption Kinetics of 4He at Low Temperatures

general results a r e similar : The characteristic lengths of helicity a r e larger than those of the energy, and the helicity again oscillates between positive and negative values at all smaller scales. The data at 1 AU were taken in a s t ream interaction region13 and included both slow stream and fast stream intervals. Thus these results suggest that there is nothing atypical in the data shown in Figs. 1 and 2. A detailed analysis of the solar wind magnetic field structure at several additional locations in the heliosphere during different time periods and in different types of morphological environments is in preparation and will be presented in a more complete paper. We thank the Voyager magnetometer team for help and cooperation in the data analysis, W. H. Mish for aid with the numerical analysis, and D. Montgomery and L. Turner for many stimulating conversations. This research was supported in part by the National Aeronautics and Space Administration under Grant No. NSG-7416. One of us (W.H.M.) i s a National Academy of ScienceNational Research Council resident post doctoral research associate.