workshop on Space Plasma Phenomena at the Collisional/Non-collisional Interplay Meudon Observatory FINAL REPORT by

We present the final report of the workshop on “Space Plasma Phenomena at the Collisional/Non-collisional Interplay” held at the “Chateau” of Meudon Observatory during June 18–29, 2001. The workshop allowed 15 scientists belonging to 13 institutions from the Czech Republic, France, Germany, Italy, United Kingdom and USA to gather and to tackle a number of problems in Plasma Physics at various degrees of collisionality typical of the Space environment. Three broad areas were considered involving three working groups: a) ‘Vlasov Plasma Theory and Simulations’ (i.e. novel and critical approaches to Vlasov plasma theory); b) ‘Kinetic effects on MHD wave propagation’ (i.e. the problem of the ‘hybrid treatment of plasmas’); c) ‘Fluid phenomena in plasmas’ (i.e. the fluid treatment of fast particle populations). The main results of the workshop were: i) the concomitant and successful benchmarking and tuning of several numerical codes on a suite of kinetic, ‘hybrid’ and fluid plasma problems (including the exchange of several such codes by participants); ii) theoretically new and numerically compact approach to Vlasov Plasma theory (‘ q -space’ and Chebyshev approaches); iii) a novel approach to the effect of correlations in plasmas (i.e. a revision of the foundations of Vlasov theory); iv) a study of MHD turbulence at high numerical resolution (i.e. novel results on the long standing riddle of the small-scale MHD turbulent power spectrum). Nine publications were laid out during the workshop to be authored by participants belonging to different institutions. The total cost of the workshop was FFr. 53,300.