Annual report - 2007
Introduction
Bepi Colombo is a joint ESA and JAXA mission that consists of two spacecraft, MMO (Mercury magnetospheric orbiter) and MPO (Mercury planetary orbiter). The preparation of MPO is coordinated by ESA, whereas JAXA is responsible for MMO. The present project is related to the MEA electron analyzer that is a part of the scientific payload onboard MMO. The present PECS project was originally proposed for the 2006 - 2009 period, in accord with the schedule of the Mercury Plasma Particle Experiment (MPPE) for MMO. However, the approval process was rather long and thus the project was rescheduled for the 2007-2010 years. The project agreement was signed on April 30, 2007 but the work on the project started at the beginning of 2007.
1. Objectives planned for the reporting period
2. Results achieved
WP1 - calibration facility
In the technical part of the project, we have prepared two vacuum chambers. The large vessel, see Fig.1a, (~80 liters) is aimed for vacuum tests of electronic blocks, whereas the smaller one was equipped with the helium UV source (~22 eV) and electron gun (300 eV - 5 keV). The UV source with an auxiliary pumping unit is now tested. Fig. 1b shows the vacuum vessel with the two main pumping units in the bottom part, UV lamp and corresponding vacuum system on the right hand side and electron gun on the left.
Obr.č.1a 
WP2-5 - Scientific part.
The results of the scientific part were subject of 6 publications in scientific journals, 8 papers in conference proceedings and 29 contributions to 7 international conferences. All of them are listed in section 7, and copies of major scientific papers are attached. For this reason, we will give here only a very brief overview of the results that were subject of conference contributions and that were not published yet. However, almost all these topics will be a subject of a further investigation and publication in journals in course of oncoming years.
WP2 - Solar wind instabilities.
WP3 - Interaction of discontinuities with the bow shock.
WP4 - Magnetopause processes.
This rate is a function of the magnetic shear across the magnetopause that is determined by an orientation of the magnetic field in the magnetosheath that is often highly fluctuating. For this reason, we have carried out a study of a correlation length of the magnetosheath fluctuations that has brought a very surprising result. This length is only several thousands of kilometers, i.e. much smaller than the wavelength of the plasma waves in the investigated frequency range. Moreover, the correlation length does not depend on the orientation of the magnetosheath flow or magnetic field as can be seen from Fig. 2.
The investigation of the magnetospheric layer adjacent to the magnetopause (LLBL) has shown that this layer is generally decoupled from the magnetosheath but that its parameters can follow abrupt changes of upstream conditions as Fig. 3 demonstrates.
WP5 - Inner magnetosphere.
The other direction of investigations was the study of propagation of disturbances induced by interplanetary shocks through the inner magnetosphere. The study has provided the speed of shocks and has shown that the shock profile can differ significantly in different positions of the observing spacecraft. A better understanding requires the computer modeling that is in progress now.
czechspace.cz
