Structure of current sheets in the sector boundaries - Helios 2 observations during early 1976

The orientation and structure of 14 current sheets are examined. Most of the observed sheets can be interpreted as tangential discontinuities that are, on the average, inclined at large angles with respect to the ecliptic plane, and have a typical thickness ranging from 1000 to 6000 km. Results do not show any evidence for a variation of the physical characteristics of the boundaries with time or heliocentric distances. The implications of a comparison between present results and the global configuration of the sector boundary surface are discussed, and it is concluded that the multiplicity of events within individual transition regions may suggest fluctuations of the sector boundary surface on the fine scale.