Glass Track Detectors Research Articles

Cluster decay of 230U via Ne emission

By using glass track detectors in 4π geometry we measured the branching ratio of 230U for emission of Ne clusters to be B=(4.8±2.0)×10 −14 and an upper limit for 18O emission from 226Th to be B<3.2×10 −14 . On the basis of theoretical calculations, the most probable neon cluster comes out to be 22Ne.

Track etching characteristics of glass track detectors

Samples of barium phosphate (BP-1), soda and quartz glasses have been irrdiated by the 238U (11.4 MeV) ion beam available from the heavy ion UNILAC accelerator at GSI, Darmstadt, Germany. After chemical etching of these specimen samples in appropriate etchants at different temperatures, the values of etched track parameters, viz. bulk etch rate, track etch rate, sensitivity, etching efficiency and the critical of etching, have been determined. The activation energies for bulk and track etch rates have also been determined. Finally, a comparison of the track etch parameters for these glass detectors has been made.

The etching characteristics of phosphate glass track detectors

The etching characteristics of phosphate glasses of types VG-13 and PSK-50 have been studied under various etching conditions using relativistic heavy ions 238 U, 197 Au and 139 La. The addition of KF to HBF 4 solution markedly increases the sensitivity of VG-13. The effects of concentration of KF on s (= v T / v G ) were studied. For La ions ( Z/β=63 ), s was measured to be about 1.15.

Thermal effects of heavy ion radiation damage in glass track detectors

Abstract The radiation damage after bombardment with high energy particles is believed to becaused by the displacement of atoms from their normal sites. These displaced atoms tendto return to their original positions particularly during annealing. The thermal effects caused by 238U having ion beam energies 15.0 and 5.9 MeV/n were studied insodalime, phosphate and silicate glass detectors. The annealing kinetics of these radiation damaged tracks is discussed using both isochronal and isothermal processes. A modified formulation developed earlier is employed to calculate the activation energy of annealing.

Effect of oxygen on response of plastic and glass track detectors

Using beams of relativistic Au and U ions, we have found that the sensitivity (reduced track etch rate) of CR-39, Rodyne polycarbonate, and Cronar polyester track detectors depends on the length of time for which the sample is exposed to oxygen before irradiation and to the partial pressure of oxygen before and during irradiation. In contrast, the sensitivity of VG-13 phosphate glass detectors is independent of the presence or absence of oxygen before or during irradiation.

Charge ( Z)- and [formula omitted]-threshold values of some track detectors: Measurements and use in nuclear reaction studies

We have prepared three glass track detectors with new chemical compositions. The detectors were tested for the detection of heavy charged particles. Experimentation was carried out in order to calibrate (a) the previously existing plastic, glass, and crystalline track detectors, and (b) the glass detectors fabricated by us. Charged particles ranging from protons to uranium ions were employed in these calibration studies. We have used the results so obtained for the estimation of charge ( Z)- and Z β - values of the reaction products emitted in the interaction of 86 MeV nucleon 18O-ions with niobium, hafnium, bismuth, and thorium targets. An attempt has been made to determine the possible reaction mechanism responsible for such interactions.

Etchable track formation in glasses: Values of some basic parameters

Abstract Formation of etchable tracks in a variety of glasses has been studied. Three new types of glass track detectors were prepared and tested for the detection of heavy charged particles. Extensive experimentation was carried out in order to (a) optimize the chemical compositions of these glasses for their use as track detectors, and (b) to determine Z- and Z/β-track registration threshold values of these and of other commonly available glass track detectors. It is expected that a knowledge of the threshold values of these glasses besides being useful in quantitative applications is expected to enhance our understanding of the mechanism of etchable latent damage trail formation in glassy media.

Determination of charge (Z) - and Z/β - threshold values for different glass and plastic track detectors

Abstract Charge (Z) - and (Z/β)-threshold values of (a) a number of glass track detectors, (b) plastic track detectors such as CR-39, CN-85, Makrofol E, Lexan, and (c) Muscovite mica have been determined experimentally. The calibrated threshold detectors were used for the estimation of charge (Z) and Z/β values of the reaction products emitted in the interaction of 86 MeV/nucleon 18O with 180Hf targets.

Study of 132Xe ion tracks in a soda glass detector

Soda glass track detectors have been exposed to 132Xe ion cyclotron beams at the Joint Institute for Nuclear Research, Dubna (USSR). The etch pit diameters are measured for different etching times after etching the detectors in a ‘new etchant’ free of the adverse effect of the etch product layer. The computed values of energy loss, dE dx , in soda glass have been correlated with the track diameter. The energy resolution of soda glass and the critical angle for etching of 132Xe ion tracks in glass detectors have also been determined. The maximum etched track length of Xe ions in soda glass has been compared with the theoretical range. The effects of different annealing conditions on the bulk etch rate, the track etch rate, the etching efficiency, the track diameter and on the range of Xe ions in soda glass have been studied.

Multifragment emission in the interaction of 86 MeV/μ 18O-ions with 197Au, 184W, and 106Ag

Thin targets of 197Au, 184W, and 106Ag were vacuum deposited on Muscovite mica, CR-39, Makrofol-E, and phosphate glass track detectors. The ‘target-detector’ assemblies were then exposed perpendicularly to 86 MeV/μ 18O ions at CERN-SC. The exposed detectors were etched in appropriate etchants for various time intervals. Correlated reaction products were scanned in order to obtain multiprong events with different multiplicities. Multiplicity-distributions, fission-and total-reaction cross-sections have been determined.

Fission fragment scattering measurements using solid state nuclear track detectors

Abstract A combination of Muscovite Mica, Phosphate Glass, and CR-39 plastic track detectors has been successfully employed in studying the phenomena of forward-, and back-scattering of fission fragments from Perspex, AI, Cu, Ho, Au, Pb, Bi, and U targets of varying thicknesses. Two different geometries were used in these studies. It was found that the fraction of the scattered-out particles increases with the increasing “Z” of the target material and that only the top 600 A or so thick layer of Bismuth is important for the scattering of Cf-252 fission fragments. Angular distribution measurements show that the scattered-out fraction decreases with the increasing angle of scattering. It has also been found that the evenness (on microscopic scale) of the target surface affects the fraction of the scattered-out fission fragments.

Measurement of nuclear reactor neutron flux with glass track detectors

ABSTRACT Integrated reactor neutron flux must be measured when samples to be dated or to be analysed for uranium content are irradiated with neutrons in nuclear reactor. A method has been suggested to measure the integrated reactor neutron flux by counting the track density on a glass surface and before and after etching determining the change of thickness of the glass which is irradiated together with the analysed samples. This method is based on the fact that the track density increases linearly as the thickness of the glass decreases during the first stage when the tracks were being etched. Two parameters (glass constants) have been defined for glass track detectors according to the analysis of the behaviour of the track density. Two kinds of glasses have been calibrated in nuclear reactor core with known integrated neutron flux. The glasses can be used to measure the neutron flux ranging from 1014 to 1018 n/cm2 with an accuracy of about ± 7%. The measurements of reactor neutron flux with these glasses and with cobalt activation foils are in good agreement. The advantages of the calibrating method are: it is easy to perform and can provide sufficient quantity of glasses after calibrating only once. The method of calibrating glasses is also presented.

Dependence of etch pit cone angles in glass track detectors on the energy and charge of the particles

Soda lime and phosphate glass solid state nuclear track detectors (SSNTD) have been exposed to 84Kr, 136Xe, and 238U ions of various energy from the UNILAC (GSI, Darmstadt, West Germany). The etch pits were broken along the lengths/heights of the cones and scanning electron microscope (SEM) analysis of their side views was carried out. Detailed SEM studies indicate that the cone angle (θ) and the critical angle of etching (θ c), decrease with the increasing Z of the incoming particle. On the other hand, there does not seem to be any significant dependence on the initial energy of the projectiles. Phosphate glass has been found to yield much smaller values of θ and θ c as compared to that produced by a soda lime glass detector for the same projectiles. The studies suggest that these results can be profitably employed for the determination of the Z of the particle.

Low-sensitivity glass track detectors

An attempt has been made to manufacture a low-sensitivity glass track detector. It has been found that strontium-magnesium glass has the lowest sensitivity to heavy ions and provides visual discrimination between the tracks of fission fragments and those due to zinc ions.

Direct Evidence for Multiple Sequential Fission in the Interaction ofPb208andU238with Uranium

In coincidence experiments using mica and glass track detectors four- and five-pronged events have been observed in 1785-MeV $^{238}\mathrm{U}$+${\mathrm{U}}_{\mathrm{nat}}$ and 1535-MeV $^{208}\mathrm{Pb}$+${\mathrm{U}}_{\mathrm{nat}}$. The events are shown to be due to multiple sequential fission. Angular distributions are presented.

Etching of glass solid state nuclear track detectors in aqueous solutions of (NH 4)HF 2, NaOH and KOH

Experiments have been carried out on fission fragment track development characteristics of soda-lime glass track detectors when etched in aqueous solutions of (NH 4)HF 2, NaOH and KOH. The parameters studied include track development efficiency, etch pit diameter, and etching velocities. The results show that among these etchants ammonium biflouride has the maximum, and NaOH the minimum track development efficiency. In order to optimise etching conditions various etchant concentrations have been tried. The comparison of these results with those obtained by using HF indicates (1) that aqueous solutions of NaOH and KOH are less efficient and produce shallower tracks than those produced by HF, and (2) that the development efficiencies of HF acid and aqueous solutions of (NH 4)HF 2 are quite comparable.

Study by track detectors of the 580-MeV photofission of U, Au, Te, Ag, Se, Cu and Cr

The fission of U, Au, Te, Ag, Se, Cu and Cr induced by photons with a maximum energy of 580 MeV has been investigated using mica and glass track detectors in a sandwich configuration.

The role of pre-irradiation annealing in changing the track development characteristics of glass track detectors

Annealing experiments have been carried out to study the changes brought about by pre-irradiation annealing in the track registration properties of a soda lime glass detector. It has been observed that as the pre-irradiation annealing temperature is raised from room temperature to its softening point, the registration efficiency at first shows an increase and then, after going through a peak at about 275°C, returns to the unannealed values. Under the present experimental conditions an enhancement of as much as 30% can be achieved in efficiency for the optimum annealing temperature. This effect may be due to a likely devitrification of the glass, and an increase in its crystallinity, under the particular annealing conditions.

Solar flare particles - Energy-dependent composition and relationship to solar composition

view Abstract Citations (42) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Solar flare particles: energy-dependent dependent composition and relationship to solar composition. Crawford, H. J. ; Price, P. B. ; Cartwright, B. G. ; Sullivan, J. D. Abstract Plastic and glass track detectors on rockets and Apollo spacecraft have been used to determine the composition of particles from He to Ni at energies from 0.1 to 50 MeV per nucleon in several solar flares of widely varying intensities. At low energies the composition of solar particles is enriched in heavy elements by an amount, relative to the asymptotic high-energy composition, that increases with atomic number from Z = 2 up to at least Z = 50, that decreases with energy, and that varies from flare to flare. At high energies (usually beyond an energy of 5 to 20 MeV per nucleon) the composition becomes independent of energy and, though somewhat variable from flare to flare, approximates the composition of the solar atmosphere. A table of abundances of the even-Z elements from He to Ni (plus N) in solar particles is constructed by averaging the asymptotic high-energy abundances in several flares. Publication: The Astrophysical Journal Pub Date: January 1975 DOI: 10.1086/153320 Bibcode: 1975ApJ...195..213C Keywords: Abundance; Solar Corpuscular Radiation; Solar Cosmic Rays; Solar Flares; Apollo Flights; Chemical Composition; Particle Production; Particle Tracks; Rocket Sounding; Solar Physics full text sources ADS |