A new nuclear track filter of CR-39

Nuclear track filters are used in more and more fields of science and technology. This paper presents a nuclear track filter of the plastic CR-39, a material not used for that purpose up to now. In comparison with other microfilters like those of Makrofol-polycarbonate, Kodak-cellulose nitrate, Lavsan-polyester and others this filter shows geometrically exact pores and no roughness of its surface or of the inner walls of the pores. This is a very important fact for theoretical studies of the laminar air flow through a nuclear microfilter. Furthermore optical investigations (range: 210 nm to 660 nm) have been made and the high transparency of CR-39 makes this microfilter very promising for optical investigations e.g. on collected aerosol particles. (author)