| 1. |
- Broitman, Esteban, 1958-, et al.
(författare)
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Influence of deposition parameters on the microstructure of ion-plated films
- 1996
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Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP). - 0094-243X .- 1551-7616. ; 378, s. 356-359
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Tidskriftsartikel (refereegranskat)abstract
- Ion plating is essentially vapor deposition onto a substrate which is the cathode of a glow discharge. The most important characteristic of the technique is that the growing film is subjected to a flux of high energy particles (neutrals and ions). In this study we report information about the effect of ion plating parameters on grain diameter and crystallite size distribution. At a constant potential grain size remains constant with the increase of ion density. On the other hand, at a constant ion density the grain size decreases with the substrate potential increment. Ion bombardment also has an effect on the crystallite size distribution. The ion plated films show a higher degree of uniformity in grain size than vacuum evaporated films. In contrast with vacuum evaporated films, where the grain size is proportional to the thickness, no variation of grain size with film thickness has been observed for the ion‐plated films. Electron diffraction patterns have shown that the orientation remains near random over the entire J and V range studied.
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| 2. |
- Gadea, A., et al.
(författare)
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Spectroscopy at N=Z with EUROBALL III
- 1999
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. ; 495, s. 195-198
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Konferensbidrag (refereegranskat)abstract
- A complete study of the nuclear structure by means of gamma spectroscopy requires, in addition to the high resolution gamma measurement and accurate DCO's or angular distributions, the information concerning the Electric or Magnetic character of the transition. This information for transitions in nuclei far from stability valley is now reachable in the new generation of Ge-arrays based in composite detectors. EUROBALL III is a good example with the high polarization sensitivity of the 90 degrees ring of Clovers. The Polarization correlations PCO's measured in coincidence with the Cluster detectors permits to investigate transitions in weakly populated nuclei. In this contribution we present results on medium mass N=Z nuclei measured with EUROBALL III coupled with light particle ancillary detectors.
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| 3. |
- Kalli, K., et al.
(författare)
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Room temperature hydrogen gas detection with optically thin palladium films on silicon oxide using photomodulated thermoreflectance
- 1999
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Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP). - 0094-243X .- 1551-7616. ; 463, s. 220-222
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Tidskriftsartikel (refereegranskat)abstract
- The sensitivity of various thicknesses of optically thin film Pd layers evaporated into a silicon oxide substrate is investigated in the presence of a hydrogen/air atmosphere at room temperature. The magnitude of the resulting reflectivity change is measured using an excite-probe technique, through laser excited photothermal modulation of a probe beam. Data indicates that concentrations of 0.1% hydrogen in a balanced air mixture and at room temperature may be measured with. an 8nm Pd film. Inhomogeneities in the Pd layers lead to anomalous behavior.
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| 4. |
- Rudolph, Dirk, et al.
(författare)
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Prompt Particle Decays of Deformed Bands and Nuclear Structure near 56Ni
- 1999
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. ; 481, s. 192-206
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Konferensbidrag (refereegranskat)abstract
- Excited states in neutron-deficient mass A similar to 60 nuclei were studied by means of several heavy-ion fusion-evaporation reactions. The G(AMMASPHERE) array in conjunction with ancillary detector systems such as MICROBALL and neutron detectors allowed for the identification of well deformed rotational structures in the second well of nuclei in the direct vicinity of the doubly-magic isotope Ni-56. Most interestingly, some of these bands were found to decay by prompt particle emission in competition to the expected gamma decay-out. Experimental details of this decay mode are presented. The rotational bands are interpreted with mean-field and large-scale shell-model calculations.
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| 5. |
- Mångård, Måns, 1969-, et al.
(författare)
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Optimal conditions for X-ray imaging by mathematical simulation
- 1999
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Ingår i: AIP Conference Proceedings 509. - : AIP. - 0094-243X. - 1563969300 ; , s. 665-672
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Konferensbidrag (refereegranskat)abstract
- Image quality strongly affects the detectability, which is the possibility to detect defects. To obtain maximum detectability it is necessary to conduct the testing with optimal equipment settings. In radiography and computerized tomography based on conventional poly-energetic x-rays, the optimal equipment settings depend on the imaging task. An imaging task is defined as testing of a specific object with a specific defect, defined by composition and geometry. However, the optimal equipment settings (e.g., x-ray tube potential, x-ray filtration and exposure time) are tedious to find experimentally. This is particularly true for industrial applications due to the wide range of imaging tasks. In this work, mathematical models of the image collection process for radiography and computerized tomography have been developed. The objective has been to develop techniques to aid the imaging operator to find optimal imaging parameters. With the models it is possible to find the optimal settings and to predict the detectability of defects in terms of its size as a function of imaged object diameter and these are formulated in terms of detectable detail—object diameter diagram. It is shown that the image quality is very sensitive with respect to the settings, with e.g., slightly non-optimal choice of x-ray filter thickness leading to a loss of image quality that cannot be compensated by varying the x-ray tube potential. Furthermore, non-optimal conditions are found to considerably reduce the detectability of defects, especially for large objects.
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| 6. |
- Wahlström, Claes-Göran, et al.
(författare)
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High-order harmonic generation
- 1995
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Ingår i: The 4th International Colloquium: X-ray Lasers 1994. - : AIP. ; 332:1, s. 312-319
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Konferensbidrag (refereegranskat)
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