Simple 3D distributions of the interplanetary dust cloud deríved from observations in the visible and distributions suggested by IR investigators are compared. Predictions of visual brightness based on IR models are falrly compatible with observations for large (ε<70°) elongations but not close to the Sun. Some reasons for this behaviour and first steps towards more realistic models are díscussed.
The dominant forces determining the motion of interplanetary particulates are gravitation, solar radiation pressure and Lorentz force. The latter two becoming significant for micron- and submicron- sized particles. In situ measurements by spaceprobes, microcrater distributions and remote observations both in the IR and visible wavelength range have established the mass frequency and spatial distribution of dust particles in interplanetary space. Consequences of the Poynting-Robertson effect and mutual collisions on these distributions and the contributions of various sources (interstellar dust, asteroids and comets) are discussed. It is shown that the contribution from a distributed source of large particles in the inner solar system is most important. Collisions between these meteor sized particles (m > 10^-5 g) produce large amounts of zodiacal light particles (10^-5 g to 10^-10 g) and
β-meteoroids (m < 10^-10 g) which leave the solar system on hyperbolic orbits. At the present time the Poynting-Robertson effect transports into the inner solar system less than 10% of the zodiacal light particles which are produced by collisions from bigger particles.
Kinetic equations for the distribution function of dust particles in mass and element spaces are formulated. Erosive as well as catastrophic collisions are taken into account. Sputtering is also included and radiative effects are considered. Initial conditions are derived from the Interplanetary Flux Model for mass distribution, and fan or cosine models for spatial density.
Dust particles of sizes between 1 micron and 100 microns from various materials have been contained with help of quadrupole field in vacuum chamber at pressures from 10^-4 to 10^-6 mbar and charged by Ar^+ ions of energies up to 3 keV as well as by electrons of energies up to 5 keV. For damping of particles motion at low
pressures the damping system with photomultipliers and feedback circuits was developed. By charging with Ar^+ ions charge-to-mass ratios up to 4 C kg^-1 were measured and dependence of maximum charge-to-mass ratio on the energy of ions was studied. Measurements of parameters of secondary electron emission by charging with electrons at different chamber pressures were started.