The chlorophyll fluorescence Fo, excited by polsed ultra-weak blue radiatíon, and thermoluminescence (TL) were recorded in ďie same sample. Temperature-dependent variations of the fluorescence yield influenced ťhe TL emission.
The method to determine the inclination distribution of zodiacal particle orbits according to 3D-density models of zodiacal dust presented by Giese and Kneißel (1987, this volume) is briefly discussed. The results show that models with additional bulges at the solar poles bear an isotropic component of the inclination
distribution amounting up to 20% of all orbits, whereas infrared models show almost no isotropic component. The existence of an isotropic component for zodiacal dust orbits is questioned by comparison with the orbital elements of meteoroidal particles which serve as a source for the zodiacal dust by mutual collisions