Nucl. Tracks Radiat. Meas., Vol. 20, No. 2, pp. 383--387,1992 Int. J. Radiat. ,4ppL Instrum., Part D Printed in Great Britain 0735-245X/92 $5.00 + .00 © 1992 PergamonPress Ltd SHORT COMMUNICATION DESIGN AND CONSTRUCTION OF AN ELECTROCHEMICAL ETCHING POWER SUPPLY GUILLERMO ESPlNOSA,*FRANCISCO FERN~,NDEZ and VICTOR M. CASTA~O Instituto de Fisica, U.N.A.M., Apartado Postal 20-364, 01000 Mexico, D. F. Mexico (Received 13 January 1992) Almtrmet--An original design for a high-voltage power supply for electrochemical etching of latent nuclear tracks is presented. The device is analysed in terms of each of its block components and its performance with and without loading. Some of the main advantages of the design, besides the electronic performance, are its portability and low power consumption. 1. INTRODUCTION FOR ~ ~ working in the field of particle track detection, efficient etching of plastic (polymeric) detectors is a well-known problem. Indeed, it is sometimes difficult to decide whether to use chemical or electrochemical etching, when processing time and cost are considered. Since the introduction of electrochemical etching (ECE) in the 1970s (Tommasino, 1970; Tommasino and Armellini, 1973), a number of systems intended to produce dielectric breakdown (also known as treeing) have been developed, especially in the case of polymeric detectors which are widely used nowa- days in a variety of applications such as particle accelerators, nuclear reactions, personal and environ. mental dosimetry, radon measurements and, in general, in every case where solid state nuclear track detectors (SSNTDs) are utilized (Tayyeb et al., 1988). The main advantage of ECE is that it allows an enlargement of the latent track produced by radi- ation. This, associated with some physicochemical parameters such as the concentration of the etchant solution, temperature, wave form, frequency and voltage, gives the possibility of determining the characteristics of the incident radiation (i.e. energy, nature, etc.). Generally speaking, one of the most important parameters to be taken into account when designing a workable ECE system is the high- voltage high-frequency power supply. In this present work we report our design of a high-voltage power supply that requires low power for operating and which can be used both in field or in laboratory conditions. 2. GENERAL DESCRIPTION OF THE ELECTRONIC SYSTEM As already mentioned, various interesting designs for high-voltage power supplies have been reported in the literature during the last 20 yr (Matiullah et al., 1987; Tommasino, 1970; Tommasino and Armellini, 1973). Nevertheless, it is still a challenge for elec- tronics designers to offer a power supply with a high adaptability to the available ECE chambers, flexi- bility in its voltage and frequency ranges and, above all, absolute control over all the detectors to be recorded. Our present design has been developed through various stages in the generation of the signal as well as high-voltage production. We mention this because it could prove interesting to know our experi- ences for people thinking of building their own dedicated power supply. In 1975, the first prototype was built, based upon a commercial television "fly- back". This power supply produced an acceptable high-voltage but the output power was rather low and the signal was distorted. After this attempt a solenoid from an automobile was utilized and a high voltage was achieved; the efficiency, however, was extremely low and the treeing was not obtained in most cases. Further, Lawrence Livermore National Laboratory technology (Griffith and McMahon, 1982) was used successfully and it was possible to handle up to 50 detectors at a time. Unfortunately, the current employed and the heat dissipated were too high. The current design, based on an output trans- former built with materials designed for good per- formance at high frequencies, utilizes integrated *CICESE Graduate Student. 383