ISSN:0021-1915    

DOI:10.1080/10256019008624293

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The state of the art in the title field including vacuum thermochromatography and sublimatography is discussed. Thermochromatography has proven to be effective in studying properties of the transactinoid elements, in separation of products from spallation reactions, in the production of radionuclides for nuclear medicine. Applications of the method for the radiochemical activation analysis seem especially prospective. From the theoretical side, the dependence of deposition temperatures on experimental parameters is reasonably well understood for uniform surfaces while reported theoretical calculations of peak shapes have not yet been confronted with the experimental data extensively enough. The case of nonuniform surfaces is a problem for future research. Some interesting non-analytical applications of the method can be suggested, such as measuring the diffusion coefficients of the adsorbates and enthalpies and entropies of adsorption.

ISSN:0021-1915    

DOI:10.1080/10256019008624294

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Emission of spoliation products with mass numbers A = 147 − 173 from tantalum targets irradiated by 660 MeV protons has been investigated. Cascade-evaporation model calculations are compared to experimental results and data for smaller energies and various targets. Calculations are in agreement with experiments. Relations allowing to estimate the “practical range” of neutron deficient nuclides in thick targets have been obtained.

ISSN:0021-1915    

DOI:10.1080/10256019008624295

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Refractory metal silcides are under intensive investigation to be used as contact and interconnect materials in VLSI circuits. Ion beam mixing has been proposed as a technique for simultaneous doping and metal silicide formution. This work presents a theoretical model for calculating the different parameters required for ion beam mixing through ion implantation. The minimum ion beam energy and dose for complete mixing is calculated. A plot of the obtained energy-dose relation shows that the dose increases linearly with energy. The dose-silicide thickness relation is also plotted. It is found that the thickness of the formed metal silicide increases linearly with the square root of the applied dose. A good agreement is found between the values and relations of the proposed model and experimental results.

ISSN:0021-1915    

DOI:10.1080/10256019008624296

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The present work represents the results of angular distribution measurements performed for promt gamma-rays in the range of 1.1 … 1.2. MeV due to the233U(n, f) and239Pu(n,f) reactions. The measurements yielded anisotropy values found to be consistent with values previously measured and using the same technique at different gamma energy bands. Such consistency, also found to exist between anisotropy values previously measured for the235U(n,f) reaction, is a strong evidence about the energy independence of the anisotropy and indicates that the gamma spectra (at 180° and 90° to the fission direction) are essentially the same. The average values of the fragment angular momentum were calculated according to Strutinsky and Nix-Swiatecki theories. It was found that the values of the average angular momentum calculated for234U,236U and240Pu according to Strutinsky,s formula (at different gamma energy bands) are consistent and yield average values which are in good agreement with those obtained from direct measurements.

ISSN:0021-1915    

DOI:10.1080/10256019008624297

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The flow rate of some liquids (water, heptane, toluene, xylene, dodecane) through Kapton nuclear track filters has been measured. The results can be interpreted with a modified Poiseuille formula. The influence of the viscosity of the liquids on their throughput through Kapton nuclear track filters has been determined. The purification of liquids with Kapton filters has been investigated. It is possible to measure the density of solid particles in deionized water by using Kapton filters. Consequently, nuclear track filters can remove solid particles from high-purity liquids. The soaking effect of some common liquid chemicals on Kapton filters has also been studied, no such soaking could be observed in most of the cases. Finally, these Kapton nuclear track filters are compared with a filter device from Hamamatsu (Japan).

ISSN:0021-1915    

DOI:10.1080/10256019008624298

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The decay of14057La (40.3 h) to levels in14058Ce has been studied in the present work. The energies and relative intensities of 37 gamma-rays following the β−decay of14057La have been measured with high precision using Ge(Li) and HP.Ge spectrometers. log (ft) values of beta decay were determined from our gamma ray intensities using the beta branchings and a decay scheme is deduced. The sum-peak technique has been used to determine k-conversion coefficient of the transition 1596.41 keV and was found to be 6.98x10−4in an excellent agreement with the theoretical value 6.9×10−4obtained by Pauli for pure E2 transition.

ISSN:0021-1915    

DOI:10.1080/10256019008624299

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Microstructure defects play a very important role in the swelling of irradiated stainless steel. This work is a parametric study of the effects of microstructural defects on the swelling of ion-irradiated steel. For simplicity, vacancy loop effects were neglected. Cold working was found to play a complicated role in the swelling behavior. On one hand, it increase the bias to interstitial absorption due to the increase in dislocation density. On the other hand, it decreases the total flux of point defects to voids by the decrease of the point defect concentrations. Grain size has also a strong effect on swelling. It was found that large gain sizes produces higher swelling and vise versa, i.e. the larger the surface of grain boundaries the less the irradiation-produced swelling. Similar effects were found for precipitates.

ISSN:0021-1915    

DOI:10.1080/10256019008624300

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019008624301

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256019008624302

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor