9314409 Goldman Relevant new theoretical research will be performed in support of current ionospheric modification experiments. The specific focus will be on acceleration of particles and effects of spatial nonuniformity in connection with strong Langmuir and ion-acoustic wave turbulence excited in the ionosphere by an HF modifier. The new theoretical research has been motivated by airglow, incoherent scatter, and barium release experiments performed during ionospheric modification over Arecibo, PR. The mean energy and moments of the velocity distriubtion of electrons accelerated by strong Langmuir turbulence iwll be computer after systematic development of appropriate and workable theoretical acceleration models in one dimension. Numerical simulations will be based on modified versions of existing 2-time- scale fluid codes, and will be calibrated against kinetic simulations. A goal will be to determine whether or not such energetic electrons can account for the oxygenic airglowobserved during ionospheric modification. The general area of theoretical and computational research is Langmuir turbulence. Research performed under this grant is expected to be relevant also to laser-plasma interaction physics and to beam-excited Langmuir turbulence in naturally-occurring space plasmas. ***
