Pergamon Radiation Measurements, Vol. 25, Nos I-4, pp. 667--674, 1995 Copyright O 1995 Elsevier Science Ltd Printed in Great Britain. All rights reserved 1350-4487/95 $9.50 + .00 1350-4487(95)00219-7 HEAVY PARTICLE TRACKS IN POLYMERS AND POLYMERIC TRACK MEMBRANES P. Yu. APEL Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna 141980, Russia ABSTRACT The review describes the evolution and present state of the use of accelerated heavy ion beams for investigation of track radiation effects and track membrane production at FLNR JINR. The research ,and development activity on track membranes (TMs) included studies of track formation process, latent track structure, environmental effects, sensitization of tracks, track etching, methods of membrane testing, designing and constructing facilities for membrane production. Some results on the physics and chemistry' of ion tracks in polymers are described with the emphasis on the experiments performed during the last few years. KEYWORDS Polymer, irradiation, heavy ion, tracks, radiation effects, pores, etching, track membrane, filtration INTRODUCTION The frst track membranes were produced on hcavv ion cyclotrons in Dubna in the early seventies. Bv 1980 the tectmology of polyethylene terephthalate (PETP) membranes was elaborated and the first pilot machines for ion irradiation, ultraviolet treatment and chemical etching ~,ere constructed. During the next decade the facilities and technology were improved significantly. The xenon ion beams of high intensity from the U-300 cyclotron were used for the irradiation of polymeric fihns. Many attempts were made to develop new membranes of chemically or thermally stable polymers. Since 1990 the ion beams from the U-400 cyclotron have become available for the treatment of polymers. The staff of the Center of Applied Physics have been working in close cooperation with the personnel of the Flerov Laboratory' of Nuclear Reactions. That is why this report presents the results obtained by a large group of scientists mad engineers. TRACKS IN POLYMERS We have been dealing with a number of polymers. First of all it is polyethylene terephthalate. The mechanical strength and chemical compatibility of the PETP films are satisfactory' for many applications. The quality of the polyethylene terephthalate films is well reproducible which is of key import,'mce for membrane production. Polyvmylidenefluoridc (PVDF) and polypropylene (PP) are very attractive because of their chemical stability. Thin PVDF and PP films of good quality are available on the market which enables us to perform systematic studies on track formation and track etching in these polymers. Polyimides are very stable at high temperatures but, very often, the properties of commercially available films (such as sensitivity to ionizing particles) are not reproducible (Samoilova et al., 1991). This imposes a limitation on the use of thin polyimide films as a matrix of track membranes. 667