Mica Track Research Articles

Two-, three- and four-particle exit channels in the reaction of 14 MeV/amu beam of 238U with gold targets

Abstract Mica and CR-39 track detectors were used in 2π-geometry to allow coincidence measurements to be made of multiple fragments emerging in the reaction of 14 MeV/amu 238 U projectiles on 197 Au target nuclei. Targets were produced from sheets of muscovite mica as well as CR-39, both of which were coated with gold by vacuum deposition. These targets were irradiated with a beam of 238 U ions, incident normally to the surface. After etching, the heavy fragments in the two-, three-, and four-particle exit channels were identified in respect of their masses and energies. Empirical velocity-range relationships in mica, which are explicitly dependent on mass, were found by fitting the Chebyshev series to the experimental data of the elastic scattering events. A computer program has been developed for identifying the two-, three-, and four-pronged events, based on the conservation of momentum and mass. Correlation plots of the final fragment masses and the total kinetic energy loss (TKEL) for the two-pronged events due to elastic scattering, as well as for the three- and four-pronged events, have also been constructed. In addition, the cross sections for binary, ternary, and quaternary fission 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.

Etching characteristics of muscovite mica and feldspar crystalline track detectors

Abstract Experiments carried out to etch the latent damage trails in muscovite mica and feldspar crystalline track detectors show that their etching characteristics depend upon the particular crystallographic planes. Attempts have been made to study various factors causing this anisotropy. There are indications that both, Vg (the etching velocity along the general surface) and Vt (the etching velocity along the damage trail) are functions of the crystallographic planes under investigation. The results have a strong bearing in the use of crystals as charged particle detectors and in the interpretation of track analyses of lunar and meteoritic samples.

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.

Measurement of theB11+Tb159complete-fusion cross section

The complete-fusion cross section for the $^{170}\mathrm{Yb}$ compound system, formed in the reaction of 115 MeV $^{11}\mathrm{B}$ with $^{159}\mathrm{Tb}$, has been measured using a counter telescope containing a thin gas proportional counter and a Si surface-barrier detector. The result is in excellent agreement with that obtained using mica track detectors.NUCLEAR REACTIONS Complete fusion $^{159}\mathrm{Tb}$($^{11}\mathrm{B}$, $^{170}\mathrm{Yb}$*), $E=115$ MeV; measured $\ensuremath{\sigma}(\ensuremath{\theta})$ for evaporation residues.