Two high resolution velocity vector analyzers for cosmic dust particles

Two new methods are described to measure velocities and angles of incidence of charged cosmic dust particles with precisions of about 1% and 1°, respectively. Both methods employ four one−dimensional position−sensitive detectors in series. The first method utilizes a charge−dividing technique while the second utilizes a time−of−flight technique for determining the position of a particle inside the instrument. The velocity vectors are measured although mechanical interaction between the particle and the instrument is completely avoided. Applications to cosmic dust composition and collection experiments are discussed. The range of radii of measurable particles is from about 0.01 to 100 μ at velocities from 1 to 80 km/sec.