Ion Track Technology

PhysicsConsult

Reimar Spohr

PostHeaderIcon Abstract

Nuclear Track Microfilters made of Mica. P. Vater, G. Tress, R. Brandt, B. Gensw├╝rger, R. Spohr. Nuclear Instruments and Methods, vol 173 (1980) 205-210.

Production and properties of a new class of microsieves with high resistance to corrosion, chemical attack and temperature is described. At the heavy ion accelerator facility GSI, mica foils of 50 mm diameter and up to 60 pm thickness are irradiated with xenon, lead or uranium ions of specific energies up to 8.5 MeV/amu at preset doses (10^3-l0^6 cm^-2), making often use of the waste beam from nuclear research experiments. The irradiated foils are etched in hydrofluoric acid to the desired pore diameter. The side length of the rhomboidally shaped pore depends linearly on the etching time and has a Gaussian distribution of fwhm -12%. The pore size remains constant throughout the thickness of the filter. For higher porosities multiple holes occur with predictable probability. Application of these well defined microsieves is envisioned in chemical engineering for filtration of hot aggressive liquids, in environmental studies for accurate determination of airborne particles, and in diagnostic medicine for filtration of blood.