Filters
Results 1 - 10 of 52
Results 1 - 10 of 52.
Search took: 0.028 seconds
| Sort by: date | relevance |
[en] The emission of characteristic X-rays from any chemical element induced by beta particles of high energy (105-106 eV) is much higher than photon excitation, with the possible exception of selective excitation. This work describes the properties of a variable energy X-ray generator that uses 90Sr as a source of beta particles and a multitarget array in a transparent source geometry. This compact device provides, through suitable selection of the target material, over 30 monoenergetic lines spread uniformly in the energy range of between 6 and 100 keV. The X-ray photon flux thus generated has an intensity of between 102-103 s-1 sr-1 per MBq of the beta source activity. With this single beta source, the X-ray yield is higher as compared with generators using 241Am or other X- or gamma-ray sources with the same activity, and the line's intensity changes by less than a factor of three over the whole energy range
Journal
Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms; ISSN 0168-583X; 
; CODEN NIMBEU; v. 187(2); p. 259-263
; CODEN NIMBEU; v. 187(2); p. 259-263
[en] The setup was designed for in situ studies of structural transformations in materials at high temperatures. It makes possible simultaneous recording of wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) spectra from room temperature up to 1000 deg. C. The setup was installed in the National Synchrotron Light Laboratory SAXS beamline. It was applied to in situ studies of several structural transformations such as the formation and growth of liquid Bi nanodroplets embedded in a B2O3-Na2O glass and the melting of Bi nanocrystals dispersed in the same glass matrix
Journal
Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms; ISSN 0168-583X; ; CODEN NIMBEU; v. 199(1-4); p. 112-116
; CODEN NIMBEU; v. 199(1-4); p. 112-116
[en] The structural and magnetic properties of the NiFe2O4-SnO2 composite, obtained by ball-milling during different times, were investigated by X-ray diffraction, small-angle X-ray scattering, Moessbauer spectroscopy and vibrating sample magnetometry. The results showed the reduction of the crystalline particle size and modification in the nature of the system interfaces as a consequence of the mechanical treatment. Specimens with smaller particles displayed strong superparamagnetism. Large variation of the hysteresis loops for the different milling times was observed
Journal
Journal of Magnetism and Magnetic Materials; ISSN 0304-8853; ; CODEN JMMMDC; v. 272-276(6); p. 2211-2213
; CODEN JMMMDC; v. 272-276(6); p. 2211-2213
| 1 | 2 | 3 | Next |