摘要:

By help of nuclear spectroscopic methods the microscopic structure of the environments of implanted atoms can be studied. Moessbauer-effect investigations of implanted semiconductors give a dominating substitution of implanted probes and in most cases the observed radiation damage is relatively small. On the other side experiments with perturbed angular correlations (TDPAC) in comparable systems clearly proof that after implantation a high degree of radiation damage exists. Electron channelling investigations support the statements of the Moessbauer experiments. A model for the structure of radiation damaged zones where the tetrahedral coordination of the atoms is prefered strongly and where the bond angles are distributed in a random manner around the ideal values is able to interprete the measured results satisfactorily.

ISSN:0021-1915    

DOI:10.1080/10256018908624108

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A review over the importest techniques for production of thin high Tcsuperconducting films is given in consideration of laser-induced procedures. The effects appearing during the annealing processes for instance the interdiffusion, the formation of interface between the film and substrate and contamination effects are discussed. The possibilities of the avoidance of disturbing effects by the production of the high Tcsuperconducting films are investigated.

ISSN:0021-1915    

DOI:10.1080/10256018908624109

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A prerequisite to the application of MOS sensors for measurement in neutron fields is the investigation of detection of heavy ions and fission fragments using these sensors. The detection efficiency of MOS sensors for heavy ions and fission fragments depends on the angle of incidence and the energy of incident particles. Therefore, investigations were carried out for measurement of the pulse rate-voltage characteristics for different angles of incidence of heavy ions and fission fragments and for different energies of fission fragments slowed down in air. From these characteristics the angular dependence of detection efficiency and the registration threshold to the specific ionization losses of fission fragments as a function of operation voltage were determined. The experiments described in the paper were performed with129Xe ions and232Cf fission fragments.

ISSN:0021-1915    

DOI:10.1080/10256018908624110

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Samples of semiconductor silicon are cutted from large monocrystals. The location of each sample within the rod has been registered. After investigating the concentration gradients of the interesting impurities, the samples are distributed. Copper concentrations of 0.42 ppb have been determined with a relative standard deviation of 6% and without a significant difference between two laboratories.

ISSN:0021-1915    

DOI:10.1080/10256018908624111

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

With pulse radiolysis and detection by optical absorption spectroscopy in transparent, molten and highly viscous PE doped with aromatic olefins as styrene, 1-methylstyrene, 1,1′-diphenylethylene and tetraphenylethylene radical and ionic transients of these scavengers were observed. From the rapid formation behaviour of the benzyl type radicals a mechanism is concluded consisting in a fast motion of excitation energy along the polymer chain with a subsequent trapping by foreign molecules under direct dissociation into radicals. Because of the PE parent cation fragmentation ionic species derived from the aromatic olefins were generated only at scavenger concentrations of ≧ 10−2mol dm−3.

ISSN:0021-1915    

DOI:10.1080/10256018908624112

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In the present study on a CN-85 film both the characteristics of the film and the track density as a function of etching time due to alpha particles of five different energies incident to the cellulose nitrate were stated. The result shows that the CN-85 film is inhomogeneous with increasing depth and that the lower the initial energy of the alpha particles is the earlier they are revealed in etching time.

ISSN:0021-1915    

DOI:10.1080/10256018908624113

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effect of etching conditions on the energy resolution was studied. In the present work cellulose nitrate CN-85 films were used as Solid State Nuclear Track Detectors. There exists a relation between the etching condition and the energy resolution.

ISSN:0021-1915    

DOI:10.1080/10256018908624114

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The natural γ-activity of shielding and construction materials is very low. For the characterization of the intrinsic activities a very sensitive technique must be applied. In the case of the Ge(Li)γ-spectrometers the photopeak intensities are only significant for extremely low background spectrometers. An essential problem is the correction of the peak rates for attenuation of external background radiation by the sample and for self absorption in the sample. A good measure for the intrinsic activity is the integral background of the γ-spectra between 0.1 and 1 MeV. For investigating high Z materials the X-ray fluorescent peak can be used in a very advantageous manner.

ISSN:0021-1915    

DOI:10.1080/10256018908624115

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256018908624116

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0021-1915    

DOI:10.1080/10256018908624117

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor