摘要:

Zinc and cadmium metals as a heterophase impurity are found to accelerate the rate of radiolysis of alkali metal nitrates. G(NO−2) values increase further with the amount of the metal powder in an admixture. For a fixed quantity of the additive, the extent of enhancement in the rate of decomposition is observed to be dependent upon the properties of the cation. The results are attributed to the electron transfer processes occurring at the interface of the two constituents.

ISSN:1042-0150    

DOI:10.1080/10420159208220187

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The ion-bombardment-induced surface topography of polycrystalline silver was studied using the stereo-photogrammetric method. The samples were irradiated with 30keV argon ions at fairly high fluences (> 1017ions/cm2). The influence of the inclination angle of the sample in the SEM on the cone shape of a SEM-picture is discussed. To analyse the irradiated surfaces covered with cones, the SEM-stereotechnique is proposed. The measurements of the sample section perpendicular to the incidence plane are also carried out.

ISSN:1042-0150    

DOI:10.1080/10420159208220188

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The fast multicharged ion spends about 40% of energy losses on vacancy creation in the inner electron shells. This energy is transferred to the kinetic energy of electrons due to the cascade of Auger processes during ∼ 10−14s whereas the primary excited electrons receive the energy in ∼ 10−16s.

ISSN:1042-0150    

DOI:10.1080/10420159208220189

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The research results of235U fission fragments channeling in silicon semiconductor detectors of heavy ions are reported. The analysis of the pulse height defect enabled to obtain the experimental relationship between energy losses in silicon due to nuclear collisions and the energy of fission fragments in LSS-units. The experimental values obtained more than twice exceed the computed ones given by Heines and Whitehead based on Lindhard's theory.

ISSN:1042-0150    

DOI:10.1080/10420159208220190

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The angular distributions of sputtered particles for the 30 keV Ar-Ni combination have been experimentally studied using the collector technique. The distributions for the ion incidence angle in interval of 0°–80° relative to a surface normal were measured. The influence of both a direct ejection mechanism and collision cascade mechanism on the shape of these distributions has been discussed. The causes of difference between the shapes of the angular distributions of sputtered particles of nickel and the same distributions of copper are discussed too.

ISSN:1042-0150    

DOI:10.1080/10420159208220191

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The properties of BeO thermoluminescent (TL) dosimeters have been investigated in the 1.0–6.0 Gy range. Annealing procedure, fading, calibration and TL dependence on energy and dose were studied along with other relevant physical features. Supralinearity phenomena have been found above 0.5 Gy, but repeated measurements showed a marked stability and reproducibility of the TL response curvevs. dose. The BeO TLDs near tissue equivalence, good sensitivity and integrity to high radiation doses, make them especially suitable for a variety of dosimetric purposes in the radiotherapy field.

ISSN:1042-0150    

DOI:10.1080/10420159208220192

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Positron lifetime and Doppler broadening measurements have been performed on alpha-irradiated tungsten to study the evolution of defects during isochronal annealing from 100°C to 1050°C. Vacancy-impurity complexes dissociate at the earlier stages and release the vacancies. Monovacancies start migrating at 400°C. The vacancy clusters coarsen to form microvoids in the region from 350°C to 650°C and remain stable upto 750°C. Some of the clusters collapse into vacancy loops. Dislocation/vacancy loops and microvoids start annealing around 750°C. The role of impurities and grain boundaries on the annealing behaviour of the defects is also discussed.

ISSN:1042-0150    

DOI:10.1080/10420159208220193

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Structural changes of (111)Si after 10keV D+2ion implantation with fluence in the range of 1016– 1019cm−2at room temperature have been studied with cross-sectional transmission electron microscopy (XTEM), secondary ion mass spectroscopy (SIMS) and neutral molecules mass spectroscopy (NMMS).

ISSN:1042-0150    

DOI:10.1080/10420159208220194

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The EPR parameters (D, g‖andg⊥) for V2+, Ni2+and Mn2+ions in linear-chain lattice CsMgCl3at 77 K have been studied from the crystal-field theory. From these studies, one can find that the local lattice relaxation occurs in the vicinity of these paramagnetic impurity ions. The bonding angles β of MCl4-6groups in the cases of V2+and Ni2+ions are determined quantitatively from EPR data and in the case of Mn2+ion, it is estimated qualitatively. These results support the opinion that the [MX−3]nchains in one-dimensional AMX3, lattice are easily deformed to accommodate impurity ions.

ISSN:1042-0150    

DOI:10.1080/10420159208220195

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The optical absorption and EPR spectra of magnesium potassium phosphate hexahydrate (MPPH) doped with copper ions are recorded both at room and liquid nitrogen temperatures. The spectrum is characteristic of Cu2+in tetragonal symmetry. The spin-Hamiltonian parameters and molecular orbital coefficients are evaluated. A correlation between EPR and optical absorption studies is drawn.

ISSN:1042-0150    

DOI:10.1080/10420159208220196

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor