Electron Microscope Investigation on the Nature of Tracks of Fission Products in Mica

Abstract

Specimens of biotite, muscovite, artificial fluorophlogopite, and muscovite annealed at 900°C were examined using an electron microscope after having been covered with a uranium layer and irradiated in a reactor. Tracks due to fission products appeared on every specimen except biotite, and the respective diameters were put into correspondence with the resistance of the various micas to thermal decomposition. The tracks were larger in muscovite (240 A), thinner in fiuorophlogopite (150 A), and still more in dehydrated muscovite (115 A). The writers believe that the mechanism of damage has its origin in the heat released by the heavy ionizing particles. Peculiar recovery effects were often observed.

Modification of graphene supported on SiO2 substrate with swift heavy ions from atomistic simulation point

“…However, the influence of ion track formation on the supported graphene remains a mystery, though limited available experimental observations indicate that extended damages along the ion track direction can be created with SHI irradiation at an oblique angle [17,21,22]. The track formation in materials such as silica has been successfully described by the thermal spike model [16,23], in which the energy of SHI is considered to dissipate from target electrons to lattice atoms through electronphonon coupling at a short time scale. By assuming that the excited electron energy is absorbed by phonons within a radius defined by the initial electron energy distribution and the electron-phonon coupling strength, the classical molecular dynamics (MD) is capable to describe the damage mechanism of SHI to materials [24,25].…”

Growth of heavy ion-induced nanodots at the SiO2–Si interface: Correlation with ultrathin gate oxide reliability

“…It should therefore be emphasized that both electronic conduction and thermal conductivity of the SiO 2 target are then some of the key parameters of the energy conversion into atomic motion [15][16][17][18]. Our experimental work, described in this paper, is completely supported by a Ôthermal spikeÕ model [16,19].…”

Melting and shock wave creation in uranium oxide due to Coulomb explosion after a pulsed ionization

“…Bringa and Johnson supported CE mechanism [1], while many other studies favored thermal spike model [2][3][4][5]. In the thermal spike model, energetic electrons are created under a high electron stopping power and subsequent electron-lattice coupling leads to melting and lattice disorders [6][7][8]. In the CE model, swift ions cause strong electron ionization of target atoms, leading to partial electron depletion along an ion track.…”