摘要:

Any type of irradiation that displaces atoms can produce voids in non-fissile metals and alloys, consequent swelling and mechanical property effects becoming important in fast reactor design and operation. The basic reason for void formation is preferential absorption of interstitials at dislocations. Void growth depends on competition between alternative sinks for diffusing vacancies and interstitials. Irradiation and materials variables affect void formation through both the point defect behaviour and the dislocation behaviour. Void ordering and annealing effects are also discussed.

ISSN:0033-7579    

DOI:10.1080/00337577208232576

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Investigation of the kinetics of disappearance of optical absorption arising during pulse radiolysis of 14.5 M aqueous KOH solutions revealed that the laws of disappearance of absorption at λ=650 nm and λ=720 nm are different. It is suggested from the spectroscopic data obtained earlier(1)that in the region 720 nm, in addition to the hydrated electron, another short-lived particle absorbs light. The modeling of chemical processes occurring in the system by means of an analogue computer allowed to determine the extinction coefficient of this particle, which is equal to 1.0×l04I/mol cm, and also the rate constants of the reactions of its formation and disappearance.

ISSN:0033-7579    

DOI:10.1080/00337577208232577

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0033-7579    

DOI:10.1080/00337577208232578

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

In order to investigate the structural changes in alloys with different size and structure of small spherical G.P. zones and intermediate precipitates, measurement of X-ray small angle scattering were carried out at liquid nitrogen temperature for A1–4.4 at per cent Zn, AI-1.0 at per cent Ag, AI-5.0 at per cent Zn-5.0 at per cent Ag and AI-2.8 at per cent Zn-1.4 at per cent Mg alloys.

ISSN:0033-7579    

DOI:10.1080/00337577208232579

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The orientation dependence of the backscattering yield (channeling) of 1.0 MeV protons was used to investigate fast neutron-induced lattice damage in silicon and germanium single crystals. The measurements were made at room temperature and for protons incident in ⟨110⟩ crystal directions. The reactor irradiations were made, using a fast neutron flux Φ =3.3 × 10l2n/cm2-sec (E>0.1 MeV) at 60 °C, to total exposures (Φt) between 2.1 × 1017n/cm2and 3.4 × 1019n/cm2. The percent of lattice atoms displaced was not linear with neutron exposure. The displacements rose rapidly with exposure initially, then assumed a very slow rise having a dependence on neutron exposure of (Φt)0.1. This appears to be some modification of an exponential saturation mechanism. It agrees qualitatively with a thermal annealing mechanism, which predicts a flux dependent (i.e., rate of defect introduction dependent) saturation value occurring even for room temperature irradiations.

ISSN:0033-7579    

DOI:10.1080/00337577208232580

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Using a steady state concentration method we have measured the rate constants of reactions of radicals, formed upon addition of OH and eaqto pyrimidine base thymine (T)—(T+OH)=R1and (T+e−aq)=R2with methanol. We find K=(0.8±0.2).104M−1sec−1and K > 2,3.103M−1sec−1respectively.

ISSN:0033-7579    

DOI:10.1080/00337577208232581

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Diffusion controlled correlated recovery kinetics are compared for the Continuum and discrete lartice treatments. Specific results are given for the simple cubic, face-centered cubic, body-centered cubic and diamond lattices. It is concluded that samples with anisotropic damage distributions created by irradiation in different crystallographic directions will not exhibit substantial differences in their correlated recovery, but it is argued that for small capture volumes and for the treatment of the early recovery times, the discrete lattice treatment is required.

ISSN:0033-7579    

DOI:10.1080/00337577208232582

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The large-depth decrease of heavy-ion path-length, projected range, and deposited-energy distributions is calculated assuming power-cross-section nuclear stopping, and estimated in the general case. The rate of decrease can be exponential at sufficiently low incident ion energies and becomes gaussian at high energies.

ISSN:0033-7579    

DOI:10.1080/00337577208232583

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Six new EPR spectra are reported which are apparently due to intrinsic defects created in the neutron-irraditation and, in some cases, annealing of silicon. In addition a spectrum similar to, but distinct from, that due to the vacancy-phosphorus center is reported. Some tentative defect models are discussed to emphasize the features of the spectra, but more detailed studies are required to establish the identity of the defects giving rise to these spectra.

ISSN:0033-7579    

DOI:10.1080/00337577208232584

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The redistribution of the channeled ion flux in the transverse plane has been examined. General formulae describing the flux peaking effect are obtained. Main factors on which the effect depends are investigated. An analysis is made of back-scattering experiments. The study has been made for the axial and planar channeling.

ISSN:0033-7579    

DOI:10.1080/00337577208232585

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor