摘要:

Quantum theory of incoherent radiation of the above-barrier electrons and positrons in the continuum axes potential approximated by the model Coulomb potential has been developed. Analytical expression has been obtained for the spectral-angular distribution of radiation intensity.

ISSN:0033-7579    

DOI:10.1080/00337578208229924

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Data are presented on the long-term room temperature stability of γ-Ray induced defects in Ge and the response of these centres to thermal annealing. Carrier capture models involving excited states for donor and acceptor centres are also discussed.

ISSN:0033-7579    

DOI:10.1080/00337578208229925

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The rate constant of the reaction of point defects with traps located very close to a crystal surface is studied using Monte Carlo and lattice relaxation simulations. Three effects due to the crystal surface are taken into account: the semi-infinite character of the random walk, changes in defect migration energies and changes in the trapping volume.

ISSN:0033-7579    

DOI:10.1080/00337578208229926

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

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 Å 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.

ISSN:0033-7579    

DOI:10.1080/00337578208229927

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Defect levels produced inp-type silicon by 30 MeV ion implantation and their isochronal annealing behavior were studied by DLTS. Three hole traps located atEv+ 0.18 eV,Ev+ 0.28 eV andEv+ 0.33 eV were introduced at the track end of ions. From comparison with other published data we attribute these levels to single positively charged divacancy (Ev+ 0.18 eV), to Si-B3 (⟨100⟩ split-interstitialEv+ 0.28 eV), and to Si-A14 (divacancy-oxygen complexEv+ 0.33 eV). It was found that the introduction rate of observed defects shows a peak at the fluence of 5 × 1013implanted ions and then decreases at higher fluence.

ISSN:0033-7579    

DOI:10.1080/00337578208229928

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Self-ion implanted molybdenum has been annealedin situin the transmission electron microscope at temperatures up to 1000°C. At low temperatures, ∼500°C, microcrystallites are nucleated on the heavily damaged surface of the foil. The microcrystallites undergo limited growth before being consumed by growth of the underlying matrix. The later stages of annealing consist of the annihilation of point and line defects by normal, thermally-activated mechanisms. Grain boundary re-orientation has also been observed.

ISSN:0033-7579    

DOI:10.1080/00337578208229929

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Systematic measurements of the activation energy for stage III recovery for gold doped with a high concentration of vacancy sinks, are presented. The obtained activation energy of 0.71 ± 0.04 eV must be interpreted as the migration energy of single vacancies.

ISSN:0033-7579    

DOI:10.1080/00337578208229930

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Heavy-ion beams from the Uppsala EN-tandem have been used to induce desorption of ions from samples of glycylglycine, ergosterol and cesium iodide. The experimental technique, involving time-of-flight mass spectroscopy, and the apparatus are described. Secondary ion yields of (M + H)+, M+and Cs+, where M denotes the molecule, have been measured as a function of the atomic number and velocity of the fast primary ions. The results show that the desorption process is connected to the electronic part of the energy loss of the primary ion. A thermal spike model earlier presented to describe sputtering yields from uranium tetrafiuoride1induced by MeV fluorine beams is shown to reproduce some general features of the measured yield distributions.

ISSN:0033-7579    

DOI:10.1080/00337578208229931

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Room temperature Si ion implantation and solid-phase epitaxial regrowth are used to improve the crystalline quality of SOS wafers. Several thickness (0.3 μm to 0.67 μm) SOS wafers are used for the investigation of the mechanism and kinetics of solid-phase epitaxial regrowth after amorphization of the Si layer. MeV helium backscattering with channeling technique, X-ray rocking curve and TEM analysis indicate that a significant reduction in the defect density is obtained for thinner SOS wafers. An annealing time of 2 hrs at 950°C is found to be sufficient to regrow the amorphous region created by Si ion implantation and to produce good crystalline quality SOS layers. From these regrowth investigations, some alternative processess to produce low-defect-density SOS are proposed.

ISSN:0033-7579    

DOI:10.1080/00337578208229932

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A phosphorus implant inp-type silicon was analyzed by SIMS, and both the implant profile and the matrix signal were observed to exhibit some anomalous behavior. Further studies revealed the same behavior in other implants. This phenomenon was observed when ann-type dopant was implanted into ap-type matrix, or vice versa. However, some exceptions arose, making the interpretation difficult. The use of matrix signal normalization was adopted and found to improve the results.

ISSN:0033-7579    

DOI:10.1080/00337578208229933

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor