摘要:

Solid State Nuclear Track Detectors have a very great potential of applications in various fields of science and technology. In the present work we have used several track detectors for measuring high gamma doses. The detector foils were irradiated with a60Co-source. The optical density of each foil was measured using a carry Spectrometer. The changes in optical density of each detector foil due to different irradiation times have been found to be linear. The obtained results can be used to measure unknown gamma doses in the range 1 × 10−2to 6 × 10−2Mrads.

ISSN:1042-0150    

DOI:10.1080/10420159008213129

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Although hard hydrocarbon layers prepared by glow discharge (a-C:H/D films) display hydrogen contents similar to those observed in graphite saturated by hydrogen implantation, the hydrogen-recycling behaviour of both films appears to be significantly different. This is concluded from isotopic exchange measurements during 8 keV D+and 11 keV H+irradiation of hydrogenated and deuterated layers. The a-C:H/D films display a strong initial depletion, which gives slowly way for a resaturation at increasing ion fluence. In the case of saturated carbon the initial depletion appears much weaker or is even missing. This difference may be explained qualitatively by different binding states in the films resulting from the different conditions of preparation.

ISSN:1042-0150    

DOI:10.1080/10420159008213130

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Experiments of secondary electron emission induced by bombarding Si(111) target by 40 keV Na+ions were performed. The influence of target temperature and ion dose on different features of the electron energy distribution were studied. The results give evidence of trapping of Na atoms on the silicon surface which strongly depends on the temperature and on the crystalline state of the Si target. In the temperature range where the silicon surface is amorphized by the ion bombardment, the analysis of the energy distribution shows that the number of trapped Na atoms remains constant.

ISSN:1042-0150    

DOI:10.1080/10420159008213131

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Synthetic quartz crystals were irradiated with Cf-fission fragments to study track registration properties in thex-plane. It was found that the properties depend on the sense of thex-plane: the etched-track size is larger and the effective critical angle ⟨⟩ is higher on the +xx-plane than on the -x-plane and as a result the registration efficiency for fission fragments in 2Π-geometry is also higher. The development of an etched track and changes in the shape of the etched track opening with etching time are discussed. The application of this detector in neutron detection is considered.

ISSN:1042-0150    

DOI:10.1080/10420159008213132

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

In the next nearest surface region the vacancy concentration is constant and independent of the irradiation temperature between 750 and 300°C and decreases with increasing electron flux. The conentrations of interstitials and of vacancies in the sink-free bulk of the material are equal and depend on the irradiation temperature, and are almost independent of the irradiation flux. The activation migration energies of vacancies and of interstitials decrease with increasing irradiation flux.It is further shown that the dynamic steady state defect concentrations resulting from the rate equations are artificial concentrations, which will not be achieved in finite times.

ISSN:1042-0150    

DOI:10.1080/10420159008213133

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

3.5 GeV-Xenon ions-induced defects in Fe-doped 1.2.3 phases YBa2Cu3-xFexO7−δwith x = 1, 0.3 and 0.45 have been investigated by means of in situ resistance measurements at 100 K and Mossbauer spectroscopy at 300 K. Beside the exponential dependence of the resistance with Xe-fluence, the radiation effects result in the appearance on the Mossbauer absorption spectra of a fourth quadrupole doublet D4(δ≈0.3 mm/s, ΔQ4≈ 1.1 mm/s) whose relativeintensity increases with dose i.e. with latent track density. Concerning the distribution of Fe Species on Cu sites in the unperturbed part of the sample, a strong interrelation between the variations of the relative areas of quadrupole doublets D1(ΔQ1≈ 1.1 mm/s) and D3(ΔQ3≈ 0.3 mm/s) under irradiation lead us to assign the corresponding Fe species substituted on Cu(1) sites ([CuO2]∞ chains of corner sharing CuO4groups), in agreement with heat treatment analysis.

ISSN:1042-0150    

DOI:10.1080/10420159008213134

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The subsurface layers with quasi-metal hole conductivity have been observed in n- and p-Ge immersed into liquid He under the60Co-gamma-irradiation. three conditions are to be fulfilled simultaneously for the production of the layers: low temperature, direct contact between helium and germanium and gammairradiation.

ISSN:1042-0150    

DOI:10.1080/10420159008213135

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Solid-state nuclear track detectors, made of Cd doped AgCl crystals, are commonly prepared by rolling into the form of thin foils. Subsequent long-term relaxation is however needed to obtain good quality tracks. The present communication shows for the first time that this detector “ageing” is reflected in lowtemperature (77 K) luminescence spectra. Maximum of the emission band shows a slow (lasting for ∼ 100 hours) blue shift, the magnitude of which (as much as 25 nm) depends on the compression ratio caused by the rolling. The shift is believed to be due to the rearrangement of Cd++ions around freshly introduced dislocations. This finding opens the possibility of monitoring non-destructively the process of detector ageing and to determine the minimum time required for saturation.

ISSN:1042-0150    

DOI:10.1080/10420159008213136

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

By combination of energy and time of flight detection in ERDA or NRA measurement, the particles' masses can be determined, additionally to the depth information. This leads to unique depth profile determination even for complex targets. Combination with th concept of Jacobi transformations results in extremely fast measurements.In this paper, a way is shown how this concept can be realized even for accelerators ofenergies as low as about 1 MeV.

ISSN:1042-0150    

DOI:10.1080/10420159008213137

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Boron implanted metal, semiconductor and ceramic samples as well as metal-semiconductor bilayer structures were annealed thermally. Measurements of the corresponding depth distributions were performed by means of the thermal neutrondepth profiling technique.The results are evaluated in terms of diffusion coefficients whenever possible.Further, long time observations on the stability of implanted Boron are reported. In a special case, boron also served as a marker to study high temperature sublimation of the matrix.

ISSN:1042-0150    

DOI:10.1080/10420159008213138

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor