  We analyze the well observed flare-CME event from October 1, 2011
(SOL2011-10-01T09:18) covering the complete chain of action - from Sun to Earth
- for a better understanding of the dynamic evolution of the CME and its
embedded magnetic field. We study the solar surface and atmosphere associated
with the flare-CME from SDO and ground-based instruments, and also track the
CME signature off-limb from combined EUV and white-light data with STEREO. By
applying 3D reconstruction techniques (GCS, total mass) to stereoscopic
STEREO-SoHO coronagraph data, we track the temporal and spatial evolution of
the CME in interplanetary space and derive its geometry and 3D-mass. We combine
the GCS and Lundquist model results to derive the axial flux and helicity of
the MC from in-situ measurements (Wind). This is compared to nonlinear
force-free (NLFF) model results as well as to the reconnected magnetic flux
derived from the flare ribbons (flare reconnection flux) and the magnetic flux
encompassed by the associated dimming (dimming flux). We find that magnetic
reconnection processes were already ongoing before the start of the impulsive
flare phase, adding magnetic flux to the flux rope before its final eruption.
The dimming flux increases by more than 25% after the end of the flare,
indicating that magnetic flux is still added to the flux rope after eruption.
Hence, the derived flare reconnection flux is most probably a lower limit for
estimating the magnetic flux within the flux rope. We find that the magnetic
helicity and axial magnetic flux are reduced in interplanetary space by ~50%
and 75%, respectively, possibly indicating to an erosion process. A mass
increase of 10% for the CME is observed over the distance range from ~4-20 Rs.
The temporal evolution of the CME associated core dimming regions supports the
scenario that fast outflows might supply additional mass to the rear part of
the CME.
