  We discuss some aspects of magnetic reconnection which could help in
understanding many aspects of magnetic plasma interactions. We will show that
the helical structure often observed in polar jets is a natural consequence of
magnetic helicity conservation in 3D reconnection driven by a collision of two
parts of an emerging flux tube within the single emerged loop. We perform 3D
simulations by solving the time-dependent, ideal MHD equations with a uniform
initial twist. We deduce that the emergence of highly twisted magnetic flux
introduces several null points, which in turn causes reconnection between
opposite directions of magnetic field within a single loop at nearest part and
the release of the trapped twist in the form of a helical jet-like emission.
