spase://CNES/NumericalData/CDPP-Archive/Cluster-4/PEACE/CLU_PP_C4_PEA

This data set contains the Cluster 4 PEACE Prime Parameters (spin averaged). The parameters are the electron density, velocity, temperature and heat flux (derived from a subset of the moment sums calculated onboard) and instrument status. Caveats At the time of writing (March 2002) the moments data provided to CSDS are being derived only from HEEA. Thus the minimum measured electron energy is typically about 34 eV opposed to 10 eV when LEEA is included. This approach is an initial response to the frequently occurring situation that the spacecraft potential does rise above 10 volts. The spacecraft potential is at times above 34 volts, in which case the moments calculations will be include measurements of both plasma and spacecraft electrons and will not accurately describe the plasma population. These cases can usually be recognised as they have particularly high density. The spacecraft potential, when uncontrolled by ASPOC, can often reach such values, particularly in thinner plasmas (e.g., magnetotail lobes, polar cap, etc.) The CSDS Quicklook plots show spacecraft potential from EFW which will further inform the interested reader about which regions characteristically have high spacecraft potential. ASPOC operations do not occur on Spacecraft 1 at all. On about 50% of the orbits there are no ASPOC operations on the other spacecraft, and operations are typically for less than 10 hours at a time when ASPOC is in use. The PEACE Team are reconsidering their approach to provision of and validation of electron moments data to the CSDS, in the light of the problems with spacecraft potential. The PEACE team will report on the outcome in a future update of this document. Please for further relevant information consult the PEACE home page (https://www.mssl.ucl.ac.uk/www_plasma/missions/cluster/).