J. Raju

Etchable track lengths of 3.56 GeV 208Pb in various dielectric solids

Abstract Etchable track lengths of 3.56 GeV 208Pb ions in nine different dielectric materials, namely CR-39 cellulose nitrate, Lexan, Mica, Makrofol-E, Makrofol-N, Triafol-BN, Triafol-TN and X-ray film base, have been determined. The accuracy of the etchable track lengths has been determined and the values are compared with theoretical data obtained from computer codes (1) RANGE (2) TRIM and (3) the program of Henke and Benton.

Fusion-fission of 238U and 209Bi in different SSNTDs

Abstract Fusion-Fission of 238 U and 209 Bi in different SSNTDs has been studied using 4 π-geometry technique. Results indicate that the projectile ions on interaction with the atoms of the detector media form compound nuclei and subsequently scission of the compound nuclei takes place in the forward hemisphere. Intricacies involved in the analysis of such kind of events have been discussed.

Track lengths of energetic 132Xe ions in CR-39 detectors

Abstract Studies of particle tracks in solids have wide ranging applications in many diverse fields of science and technology. Most of these studies require a precise knowledge of heavy ion track lengths or ranges in various knowledge of heavy ion track lengths or ranges in various commonly used solid dielectrics. We have measured the maximum etchable track lengths of 132Xe at 12 different energies ranging from 5.8 MeV/u to 17.0 MeV/u in CR-39 (Homalite). The ion beam with an initial energy of 17.0 MeV/u was degraded by aluminium foils of different thickness. The detectors were irradiated at an angle of 45° to the beam direction and were etched for a period of 2–6 hrs in 6N NaOH at 55°C to reveal the tracks. The track lengths were measured using an optical microscope and the maximum etchable track lengths were determined. The standard deviations have been evaluated and the experimental results are compared with theoretical values obtained from computer codes ‘RANGE’ and ‘TRIM’ and the program of Henke and...

Calibration of CR-39 and ZnP-glass detectors with 350 MeV 90Zr ions

The response of sensitive detectors, CR-39 and ZnP-glass, for 350 MeV 90Zr ions, has been studied. Bulk and track-etch parameters have been evaluated by successive etching. Calibration of the two detectors has been done by correlating the measured track-etch rate (VT) with the residual range and total energy-loss rate. A linear correlation has been observed in both cases. Track registration threshold values of 4.45 MeV mg-1 cm2 for CR-39 and 12.50 MeV mg-1 cm2 for ZnP-glass have been obtained.

Response to 350 MeV 90Zr ions of polycarbonate detectors

Abstract Makrofol-KG and Polycarbonate (Bayer) plastic detectors were exposed to 350 MeV 90Zr ions for studying the heavy ion tracks. Successive etching of these detectors in 6N NaOH at 55°C has been performed in order to develop latent tracks and to evaluate bulk and track etch parameters. The detectors have been characterised by correlating the measured track-etch rate (VT) with residual range (R) and total energy-loss rate ( dE dx ). A linear dependence of VT on both R and dtE dtx has been observed in these detectors for 90Zr ions above 15 MeV. The significance and importance of the experimental results have been discussed.

VT (track etch rate): Reflection of total energy-loss rate (dE/dx) for 238U in CR-39

Registration of 238U ions of three different energies in CR-39 has been carried out. Track etch rate (VT) has been correlated with total energy-loss rate (dE/dx). The theoretically computed values of ranges from three different sources have been compared with the experimentally determined ones.

Characterization of overhead projector transparency as heavy ion detector

Abstract In an attempt to characterize overhead projector transparency (OPT) as a detector material we have carried out its elemental analysis. It has been found to be a triacetate. The optimum etching conditions were found out and the bulk etch rate V G and its activation energy E a have been determined. The maximum etchable track lengths of 252 Cf fission fragments and 132 Xe ranges at 14.5 and 5.9 MeV/u in OPT have been measured. Further work on correlation of V T and dE/dx is in progress.

Measurement of target thickness by a nuclear track technique

Abstract A new application of the nuclear track technique for the measurement of target thickness is presented here. A well collimated beam of heavy ions is allowed to penetrate through thin metal targets and the energies of the heavy ions emerging out of these targets are obtained from the maximum etchable track lengths in a suitable track detector using energy-track length calibration curve. Target thickness is then determined from range-energy calibration plots. In this paper we discuss this track technique and highlight its scope.

Computer oriented numerical analysis of nuclear track data

Abstract Solid State Nuclear Track Detectors (SSNTDs) are used in wide ranging applied fields. The application of any SSNTD is largely dependent on the determination and standardization of all the quantifiable track parameters. The measurement of various track parameters are associated with significant levels of systematic and random errors which need to be minimized. Several computer programs (TRALIN, TRAPOL1, TRAPOL2, TRACAL1, TRACAL2 and TRADIS) have been developed in high level language to analyse the measured nuclear track data in order to generate best fit to the experimental track data as linear and polynomial functions and to test the goodness of fitting. Application of these programs have been demonstrated and the mathematical formulations and logic used to develop these computer codes have been presented.

A track technique for the measurement of target thickness using heavy ions

Abstract A new application of the nuclear track technique, in the measurement of target thickness, is presented here. A well collimated beam of 14.0 MeV/u 238 U ions was allowed to penetrate through thin foils of aluminium, and the energies of the uranium ions emerging out of these foils were obtained from the maximum etchable track lengths in ZnP-glass detectors and the calibration curve. The target thickness is then evaluated from the initial and the transmitted energy of the heavy ions, and the range-energy plots. The thicknesses of the aluminium foils have been measured by this track technique and are compared with values obtained by the weighing method.