Pergamon Radiation Measurements. Vol. 28, Nos I-6, pp. 41-44, 1997 © 1997 Elsevier Science Ltd Printed in Great Britain. All rights reserved 1350-4487/97 $17.00 + 0.00 PII: S 1350-4487(97)00036.X MEAN RANGES OF 161Dy IN HOSTAPHAN AND KAPTON AND MAXIMUM ETCHABLE TRACK LENGTHS IN ZnP-GLASS DETECTOR S. GHOSH, (l) D. SINHA, (1) A.K. MAWAR,(1) S. SINGH, (1) A. SRIVASTAVA, (1'2) K.K. DWIVEDI (I) AND g. BRANDT (3) (I) Department of Chemistry, North-Eastern Hill University, Shiilong-793 003, India. (2) Department of Chemistry, Allahabad University, Allahabad-211 002, India (3) Kernchemie, FBI4, Philipps University, D-35032 Marburg, Germany. ABSTRACT The mean ranges and energy-loss of different energies of 161Dy in Hostaphan and Kapton have been determined using the nuclear track technique. Calibrated detectors of PADC are used for ~6tDy ions through targets of different thickness. The experimental mean ranges are compared with theoretical values derived from three different prescriptions. In another experiment the track lengths of t6tDy ions at five different energies were measured in Zn-P glass and the experimental track lengths have been compared with theoretical values obtained from three different computer codes. KEYWORDS Mean ranges; energy-loss; PADC detector; ~6~Dy;Hostaphan; Kapton; ZnP glass; maximum etchable track length. INTRODUCTION Solid state nuclear track detectors have found increasing use in the study of heavy ion interactions with matter. These are extensively used to measure mean ranges and energy-loss of heavy ions in any media. The knowledge of energy-loss and mean ranges for heavy ions in elemental and complex media are of great importance in many nuclear physics experiments. Due to the paucity of experimental data one resorts to values derived either from theoretical computations or from tabulations (Northcliffe and Schilling, 1970 and Hubert et al., 1990) whose validity require to be tested. In this paper we present our experimental work on measurement of mean ranges and energy-loss of 13.0 MeV/u '6'Dy in Hostaphan and Kapton using the nuclear track technique (Dwivedi, 1991) and also the maximum etchable track length of L6JDyin ZnP-glass at five different energies. The experimental results are compared with the theoretical ranges obtained from the different computer codes (Biersack and Haagmark, 1980; Dwivedi, 1988; Henke and Benton, 1968) in order to assess their validity. EXPERIMENTAL PROCEDURE Stacks of Kapton (H-polyimide) with 5 foils and Hostaphan (.polyethylene terephthalate) with 6 foils arranged in a stair-case configuration and mounted on Polyallyldiglycol carbonate (PADC), were exposed to a well collimated beam of 13.0 MeV/u ~61Dy ions. In a separate arrangement four aluminium foils were mounted on a ZnP-glass plate and exposed to 13.0 MeV/u ~6tDy ions to get five different energies of impinging ions. The irradiations were done at UNILAC, GSI, Darmstadt. The detectors were irradiated at an angle of 45 ° to the surface with an optimum fluence of 5x104 ions cm"2. The degrader foils (Kapton, Hostaphan and Aluminium) were then taken out and the PADC detectors as well as the ZnP-glass detectors were etched in 6N NaOH at 550C till the tracks were completely etched. The detectors were then taken out, washed, dried and observed under the microscope. The track- diameters and track lengths were then measured. About 200 tracks were measured in each sector of the 41