摘要:

The paper considers the recombination processes involving disordered regions (DR's). A general expression for the lifetimeTrwith respect to recombination on DR's at low injection levels is obtained under the assumption of one recombination level existing inside the DR. An analysis is made of the dependence of the lifetimeTron the equilibrium height of the potential barrier and the location of the Fermi level μ. The rate of recombination on DR's is found to be maximum at ψo = ψ0minwhere ψ0minis determined by the recombination center parameters and the majority carrier concentration is undamaged material. The temperature and injection dependences of the lifetime axe considered. The DR's are shown to introduce additional asymmetry into the trapping cross-sectionsTrapping on the centers inside a DR is considered. The DR's are proposed to be classified as “recombination DR's” when ψ0≈ ψ0min, and “trapping DR's” when ψ0> ψ0min. The effective lifetimeTeffis calculated.

ISSN:0033-7579    

DOI:10.1080/00337577608233041

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

On the basis of dielectric formalism the analytical expressions for the calculation of close collision and plasmon excitation contributions to the total energy loss of light ions (protons, α-particles) on valence electrons of metals have been obtained. The importance of accounting for the relation between the mentioned contributions while interpreting the results on ion dechannelling due to their multiple scattering on the crystal valence electrons has been pointed out. The ratio of the total energy loss for the best channelled light ions to the energy loss in the non- oriented target in the energy range ofE≈ 100 keV-500 MeV has been calculated.

ISSN:0033-7579    

DOI:10.1080/00337577608233042

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The validity of the track formation model proposed by Fleischer, Price and Walker was tested for a sensitive cellulose nitrate track detector using protons, deuterons and alpha particles. Quantitative data are given on the threshold energies and etchable track lengths of these particles. The same data were also calculated for3H,3He,6He and8He by means of the model of primary radiation damage density presented in the paper. A simple empirical relation was found for the evolution of the etch rate ratio along the particle trajectory.

ISSN:0033-7579    

DOI:10.1080/00337577608233043

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A simple and direct method for measuring neutron fluence is achieved through the induced volumetric density changes in borate glass systems after being irradiated with neutrons of an average energy 5 MeV. The fading of density of irradiated samples after storage at different temperatures has been studied.

ISSN:0033-7579    

DOI:10.1080/00337577608233044

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A model for description of charge distribution for scattering of heavy ions in the keV region, on metal surfaces developing and improving the method of Van der Weg and Bierman, and taking into account the connection between the ion charge state and scattering kinematics, is proposed.

ISSN:0033-7579    

DOI:10.1080/00337577608233045

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Une augmentation de contrainte, effectuée au cours d'une irradiation à 36 K par les fragments de fission, donne naissance à un régime de fluage transitoire. On explique cet ailongement para-élastique par un réarrangement des boucles de dislocations, au sein des pointes “thermiques” associées aux cascades de déplacements. Une telle analyse fournit les concentrations de défauts presents sous forme condensée au moment du changement de contrainte. Elle permet également de determiner le volume de matière concerné par ces rearrangements, sous l'impact d'un fragment de fission.

ISSN:0033-7579    

DOI:10.1080/00337577608233046

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Aqueous solutions of Co(III)-ethylenediamine tetraacetate (C) at different pH were irradiated with X-rays both in the presence and absence of dissolved oxygen. Radiolytic decomposition of the metal chelate and the formation of hydrogen peroxide and formaldehyde were determined. The radiolysis was found to be initiated by attack both at the ligand and at the central metal ion of the metal chelate by the free radicals derived from water. A detailed radio- lytic mechanism has been discussed. From competition kinetic studies with methanol in neutral medium the rate constant, k(OH + C) was found to be 5.3 × 108M−1sec−1.

ISSN:0033-7579    

DOI:10.1080/00337577608233047

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Enhancement of substitutional diffusion is observed in a brass (30 wt% Zn) by following the decrease in electrical resistivity with neutron irradiation of a thermally equilibrated alloy; the decrease arises from the increase in short- range order. It was determined by previous research that this diffusion enhancement is largely caused by the annealing of radiation-produced vacancies in excess of the thermal equilibrium concentration. Therefore, the results reported here are based upon a well-established technique.

ISSN:0033-7579    

DOI:10.1080/00337577608233048

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

G-values have been measured for some ammo acids and their quinone complexes radiolysed by cobalt 60 gamma rays. The G-values for the complexes are much lower than for the individual compounds. Free radical saturation occurs for the complexes at lower dosages than either the amino acids or quinones.

ISSN:0033-7579    

DOI:10.1080/00337577608233049

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

In the thermal spike model of the interaction of energetic radiation with matter, it is assumed that energy is deposited instantaneously in a very small region, producing a localized increase of temperature which spreads and dissipates according to the laws of classical heat conduction in a continuum. If an activated process (e.g. the migration of atoms, evaporation of atoms from a surface, etc.) is energized by the spike, the number of elementary steps caused by one spike can be expressed as an integral over space and time of the exponential of − Q/T(r,t), whereQis the activation energy for the process andT(r,t), is the spike temperature at positionrand timet.In the past quantitative results have been obtained from this model only with the aid of further approximations and the assumption that thermal conductivity and heat capacity are independent of temperature.

ISSN:0033-7579    

DOI:10.1080/00337577608233050

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor