摘要:

A fully dynamical computer model of a bcc crystal is used to compute the displacement energy (ED) spectrum of primary knock-on (PKO) atoms in Tungsten.EDis found to be quite directionally dependent and, when the crystal is assigned a nonzero temperature, to have a spread in energy greater than that predicted by a simple two-body argument. Furthermore, when an energy of 5 to 10 eV greater thanEDis given to the PKO in the (100) direction, there is a significant chance that an uncorrelated Frenkel pair will be produced.

ISSN:0033-7579    

DOI:10.1080/00337577608233054

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The influence of foreign atoms on the defect production rate, during reactor irradiation of aluminium at 4.6 K, has been studied by electrical resistivity measurements on a series of dilute Al(Mg) and Al(Ga) alloys. In high purity aluminium, the decrease of resistivity damage rate with increasing defect resistivity may be interpreted in terms of spontaneous recombination processes with a high incidence of dynamic effects. The presence of the addition element produces an increase of the low-dose damage rate and, for the most concentrated alloys, of the saturation value of the resistivity increment. These effects appear to be due to both deviations from Matthiessen's rule and enhanced defect production rates.

ISSN:0033-7579    

DOI:10.1080/00337577608233055

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Analytical results are obtained for the time-energy distribution of neutrons and the associated displaced atoms slowing down in an amorphous medium according to a general force law. Explicit results are given for the inverse power law, and applications to hard-sphere and Coulomb scattering are discussed. Complete results are obtained for the steady state energy distribution of particles arising from a primary knock-on, and from a neutron initiated cascade. The speed of the slowing down process is assessed by calculating the slowing down time of particles. Two different concepts of slowing down time are discussed, one based upon a density average and the other on a slowing down density average. It is shown that the latter definition is physically more realistic and mathematically simpler.

ISSN:0033-7579    

DOI:10.1080/00337577608233056

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Fission fragment track development properties ofx-cut (1, 0, 0),y-cut (0, 1, 0) andz-cut (0, 0, 1) planes in natural quartz crystals have been studied. Both HF and boiling solution of NaOH have been used as etchants. It has been found thatx-cut and y-cut planes show quite significant anisotropy in the angular distribution of etched tracks. The degree of isotropy is higher when boiling solution of NaOH is used as an etchant than HF etching. Among the planes studied, thex-cut plane is found to be the most sensitive, while no etchable tracks could be obtained inz-cut plane. In the early stages of the etching process, the degree of isotropy seems to increase with the increasing etching time. Attempts have been made to explain these observations.

ISSN:0033-7579    

DOI:10.1080/00337577608233057

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The average energy losses of channeled protons have been studied, both experimentally and theoretically, as a function of dechanneling depth in the planar channel of a W single crystal. The experimental values for the average losses have been obtained from normalized energy spectra of backscattered protons when the crystal planar channel is aligned with the beam. The theoretical description is based on the use of the approximation for continuous planar potentials and on the calculated variation of the mean energy of the transverse motion of particles with depth.

ISSN:0033-7579    

DOI:10.1080/00337577608233058

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

By monitoring the rate of the Zener relaxation, in situ measurements of the dynamic concentration of point defects associated with the bombardment by fast neutrons at intermediate temperatures (0.3–0.4Tm) have been obtained for a Ag-30 at. % Zn alloy.

ISSN:0033-7579    

DOI:10.1080/00337577608233059

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Ion or electron irradiation of silica glass produces radiation damage which results in a compaction of the structure, an increase in refractive index and an enhancement of the chemical etch rate in HF. In the light of the present data and comparisons with other measurements it is concluded that the damage produced by electronic energy loss processes differs from that induced by atomic collision events suggesting that they operate by different mechanisms. The electronic energy loss controls the chemical etch rate whereas both the compaction and refractive index changes are influenced more efficiently by the atomic collision events.

ISSN:0033-7579    

DOI:10.1080/00337577608233060

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

ISSN:0033-7579    

DOI:10.1080/00337577608233061

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

ISSN:0033-7579    

DOI:10.1080/00337577608233062

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

ISSN:0033-7579    

DOI:10.1080/00337577608233063

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor